WorldWideScience

Sample records for microalgal cultivation systems

  1. Microalgal Cultivation in Treating Liquid Digestate from Biogas Systems.

    Science.gov (United States)

    Xia, Ao; Murphy, Jerry D

    2016-04-01

    Biogas production via anaerobic digestion (AD) has rapidly developed in recent years. In addition to biogas, digestate is an important byproduct. Liquid digestate is the major fraction of digestate and may contain high levels of ammonia nitrogen. Traditional processing technologies (such as land application) require significant energy inputs and raise environmental risks (such as eutrophication). Alternatively, microalgae can efficiently remove the nutrients from digestate while producing high-value biomass that can be used for the production of biochemicals and biofuels. Both inorganic and organic carbon sources derived from biogas production can significantly improve microalgal production. Land requirement for microalgal cultivation is estimated as 3% of traditional direct land application of digestate. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Co-cultivation of fungal and microalgal cells as an efficient system for harvesting microalgal cells, lipid production and wastewater treatment.

    Directory of Open Access Journals (Sweden)

    Digby Wrede

    Full Text Available The challenges which the large scale microalgal industry is facing are associated with the high cost of key operations such as harvesting, nutrient supply and oil extraction. The high-energy input for harvesting makes current commercial microalgal biodiesel production economically unfeasible and can account for up to 50% of the total cost of biofuel production. Co-cultivation of fungal and microalgal cells is getting increasing attention because of high efficiency of bio-flocculation of microalgal cells with no requirement for added chemicals and low energy inputs. Moreover, some fungal and microalgal strains are well known for their exceptional ability to purify wastewater, generating biomass that represents a renewable and sustainable feedstock for biofuel production. We have screened the flocculation efficiency of the filamentous fungus A. fumigatus against 11 microalgae representing freshwater, marine, small (5 µm, large (over 300 µm, heterotrophic, photoautotrophic, motile and non-motile strains. Some of the strains are commercially used for biofuel production. Lipid production and composition were analysed in fungal-algal pellets grown on media containing alternative carbon, nitrogen and phosphorus sources contained in wheat straw and swine wastewater, respectively. Co-cultivation of algae and A. fumigatus cells showed additive and synergistic effects on biomass production, lipid yield and wastewater bioremediation efficiency. Analysis of fungal-algal pellet's fatty acids composition suggested that it can be tailored and optimised through co-cultivating different algae and fungi without the need for genetic modification.

  3. Co-cultivation of fungal and microalgal cells as an efficient system for harvesting microalgal cells, lipid production and wastewater treatment.

    Science.gov (United States)

    Wrede, Digby; Taha, Mohamed; Miranda, Ana F; Kadali, Krishna; Stevenson, Trevor; Ball, Andrew S; Mouradov, Aidyn

    2014-01-01

    The challenges which the large scale microalgal industry is facing are associated with the high cost of key operations such as harvesting, nutrient supply and oil extraction. The high-energy input for harvesting makes current commercial microalgal biodiesel production economically unfeasible and can account for up to 50% of the total cost of biofuel production. Co-cultivation of fungal and microalgal cells is getting increasing attention because of high efficiency of bio-flocculation of microalgal cells with no requirement for added chemicals and low energy inputs. Moreover, some fungal and microalgal strains are well known for their exceptional ability to purify wastewater, generating biomass that represents a renewable and sustainable feedstock for biofuel production. We have screened the flocculation efficiency of the filamentous fungus A. fumigatus against 11 microalgae representing freshwater, marine, small (5 µm), large (over 300 µm), heterotrophic, photoautotrophic, motile and non-motile strains. Some of the strains are commercially used for biofuel production. Lipid production and composition were analysed in fungal-algal pellets grown on media containing alternative carbon, nitrogen and phosphorus sources contained in wheat straw and swine wastewater, respectively. Co-cultivation of algae and A. fumigatus cells showed additive and synergistic effects on biomass production, lipid yield and wastewater bioremediation efficiency. Analysis of fungal-algal pellet's fatty acids composition suggested that it can be tailored and optimised through co-cultivating different algae and fungi without the need for genetic modification.

  4. A simple method for decomposition of peracetic acid in a microalgal cultivation system.

    Science.gov (United States)

    Sung, Min-Gyu; Lee, Hansol; Nam, Kibok; Rexroth, Sascha; Rögner, Matthias; Kwon, Jong-Hee; Yang, Ji-Won

    2015-03-01

    A cost-efficient process devoid of several washing steps was developed, which is related to direct cultivation following the decomposition of the sterilizer. Peracetic acid (PAA) is known to be an efficient antimicrobial agent due to its high oxidizing potential. Sterilization by 2 mM PAA demands at least 1 h incubation time for an effective disinfection. Direct degradation of PAA was demonstrated by utilizing components in conventional algal medium. Consequently, ferric ion and pH buffer (HEPES) showed a synergetic effect for the decomposition of PAA within 6 h. On the contrary, NaNO3, one of the main components in algal media, inhibits the decomposition of PAA. The improved growth of Chlorella vulgaris and Synechocystis PCC6803 was observed in the prepared BG11 by decomposition of PAA. This process involving sterilization and decomposition of PAA should help cost-efficient management of photobioreactors in a large scale for the production of value-added products and biofuels from microalgal biomass.

  5. Microalgal cultivation with biogas slurry for biofuel production.

    Science.gov (United States)

    Zhu, Liandong; Yan, Cheng; Li, Zhaohua

    2016-11-01

    Microalgal growth requires a substantial amount of chemical fertilizers. An alternative to the utilization of fertilizer is to apply biogas slurry produced through anaerobic digestion to cultivate microalgae for the production of biofuels. Plenty of studies have suggested that anaerobic digestate containing high nutrient contents is a potentially feasible nutrient source to culture microalgae. However, current literature indicates a lack of review available regarding microalgal cultivation with biogas slurry for the production of biofuels. To help fill this gap, this review highlights the integration of digestate nutrient management with microalgal production. It first unveils the current status of microalgal production, providing basic background to the topic. Subsequently, microalgal cultivation technologies using biogas slurry are discussed in detail. A scale-up scheme for simultaneous biogas upgrade and digestate application through microalgal cultivation is then proposed. Afterwards, several uncertainties that might affect this practice are explored. Finally, concluding remarks are put forward. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Microalgal cultivation and utilization in sustainable energy production

    Energy Technology Data Exchange (ETDEWEB)

    Lakaniemi, A.-M.

    2012-07-01

    Microalgae are a promising feedstock for biofuel and bioenergy production due to their high photosynthetic efficiencies, high growth rates and no need for external organic carbon supply. However, microalgal biomass cultivation for energy production purposes is still rare in commercial scale. Further research and development is needed to make microalgal derived energy sustainable and economically competitive. This work investigated cultivation of fresh water microalga Chlorella vulgaris and marine microalga Dunaliella tertiolecta and their utilization in production of hydrogen, methane, electricity, butanol and bio-oil after bulk harvesting the biomass. Growth of the two microalgae was studied in five different photobioreactor (PBR) configurations especially concentrating on the quantification and characterization of heterotrophic bacteria in non-axenic microalgal cultivations and microalgal utilization of different nitrogen sources. Anaerobic cultures used for the energy conversion processes were enriched from a mesophilic municipal sewage digester separately for production of H{sub 2}, CH{sub 4} and electricity from the two microalgal species. After culture enrichment, energy conversion yields of microalgal biomass to the different energy carriers were compared. In summary, this study demonstrated that both C. vulgaris and D. tertiolecta can be used for production of Hv(2), CHv(4), electricity, butanol and lipids. Based on this study C. vulgaris is more suitable for bioenergy production than D. tertiolecta. Depending on cellular lipid content, lipid utilization for bio-oil production and anaerobic digestion were the most potent means of converting C. vulgaris biomass to energy. The study also revealed diverse microbial communities in non-axenic microalgal photobioreactor cultures and in anaerobic consortia converting microalgal biomass to energy carriers

  7. On the use of selective environments in microalgal cultivation

    NARCIS (Netherlands)

    Mooij, P.R.

    2016-01-01

    This thesis deals with selective environments in microalgal cultivation. As explained in Chapter 1 microalgae have changed the course of life on Earth dramatically by performing oxygenic photosynthesis. In oxygenic photosynthesis electrons from water are used to reduce carbon dioxide to

  8. Microalgal Cultivation in Secondary Effluent: Recent Developments and Future Work

    Directory of Open Access Journals (Sweden)

    Junping Lv

    2017-01-01

    Full Text Available Eutrophication of water catchments and the greenhouse effect are major challenges in developing the global economy in the near future. Secondary effluents, containing high amounts of nitrogen and phosphorus, need further treatment before being discharged into receiving water bodies. At the same time, new environmentally friendly energy sources need to be developed. Integrating microalgal cultivation for the production of biodiesel feedstock with the treatment of secondary effluent is one way of addressing both issues. This article provides a comprehensive review of the latest progress in microalgal cultivation in secondary effluent to remove pollutants and accumulate lipids. Researchers have discovered that microalgae remove nitrogen and phosphorus effectively from secondary effluent, accumulating biomass and lipids in the process. Immobilization of appropriate microalgae, and establishing a consortium of microalgae and/or bacteria, were both found to be feasible ways to enhance pollutant removal and lipid production. Demonstrations of pilot-scale microalgal cultures in secondary effluent have also taken place. However there is still much work to be done in improving pollutants removal, biomass production, and lipid accumulation in secondary effluent. This includes screening microalgae, constructing the consortium, making use of flue gas and nitrogen, developing technologies related to microalgal harvesting, and using lipid-extracted algal residues (LEA.

  9. An experimental investigation of microalgal dewatering efficiency of belt filter system

    Directory of Open Access Journals (Sweden)

    Anjali Sandip

    2015-11-01

    Full Text Available The objective of this study was to investigate the microalgal dewatering efficiency of a belt filter system for feed concentrations below 10 g dry wt./L. A prototype belt filtration system designed for 50 g dry wt./L microalgal feed concentration was used for this investigation. The highest concentration of microalgal suspension available for testing on the prototype belt filtration system was 6 g dry wt./L obtained from biomass settling tanks at the Lawrence, Kansas domestic wastewater treatment plant. For preparation of feed suspension with concentrations below 10 g dry wt./L, microalgal cultivation was followed by flocculation. A mixed laboratory culture of freshwater species dominated by three eukaryotic green microalgae (Chlorella vulgaris, Scenedesmus sp., and Kirchneriella sp. was cultivated in wastewater effluent. This was followed by flocculation which resulted in a microalgal feed suspension concentration of 4 g dry wt./L. Belt dewatering tests were conducted on microalgal suspensions with feed concentrations of 4 g dry wt./L and 6 g dry wt./L. The maximum microalgal recovery with the belt dewatering system was 46% from the 4 g dry wt./L, and 84% from the 6 g dry wt./L suspensions respectively. The results of this study indicate that microalgal suspension concentrations as low as 6 g dry wt./L can be recovered with a belt filter system improving the overall dewatering efficiency of the system.

  10. Microalgal cultivation for value-added products: a critical enviro-economical assessment.

    Science.gov (United States)

    Kothari, Richa; Pandey, Arya; Ahmad, Shamshad; Kumar, Ashwani; Pathak, Vinayak V; Tyagi, V V

    2017-08-01

    The present review focuses on the cultivation of algal biomass for generating value-added products (VAP) and to assess their economic benefits and harmful environmental impact. Additionally, the impact of bioreactor designs on the yield of microalgal biomass for VAP is also considered. All these factors are discussed in relation to the impact of microalgae production on the bio-economy sector of commercial biotechnology.

  11. Aerobic treatment of swine manure to enhance anaerobic digestion and microalgal cultivation.

    Science.gov (United States)

    Bekoe, Dominic; Wang, Lijun; Zhang, Bo; Scott Todd, Matthew; Shahbazi, Abolghasem

    2018-02-01

    Aerobic treatment of swine manure was coupled with anaerobic digestion and microalgal cultivation. A 14-day aerobic treatment reduced the total solid content of swine manure by >15%. Ammonia and carbon dioxide were stripped by the air supplied, and this off-gas was further used to aerate the culture of Chlorella vulgaris. The microalgal growth rates in Bristol medium and the wastewater with the off-gas increased from 0.08 to 0.22 g/L/d and from 0.15 to 0.24 g/L/d, respectively. Meanwhile, the aerobically treated swine manure showed a higher methane yield during anaerobic digestion. The experimental results were used to establish a demonstration unit consisting of a 100 L composter, a 200 L anaerobic digester, a 60 L tubular photobioreactor, and a 300 L micro-open raceway pond.

  12. A novel one-stage cultivation/fermentation strategy for improved biogas production with microalgal biomass.

    Science.gov (United States)

    Klassen, Viktor; Blifernez-Klassen, Olga; Hoekzema, Yoep; Mussgnug, Jan H; Kruse, Olaf

    2015-12-10

    The use of alga biomass for biogas generation has been studied for over fifty years but until today, several distinct features, like inefficient degradation and low C/N ratios, limit the applicability of algal biomass for biogas production in larger scale. In this work we investigated a novel, one-stage combined cultivation/fermentation strategy including inherently progressing nitrogen starvation conditions to generate improved microalgal biomass substrates. For this strategy, comparable low amounts of nitrogen fertilizers were applied during cultivation and no additional enzymatic, chemical or physical pretreatments had to be performed. The results of this study demonstrate that progressing nitrogen limitation leads to continuously increasing C/N ratios of the biomass up to levels of 24-26 for all three tested alga strains (Chlamydomonas reinhardtii, Parachlorella kessleri and Scenedesmus obliquus). Importantly, the degradation efficiency of the algal cells increased with progressing starvation, leading to strain-specific cell disintegration efficiencies of 35%-100% during the fermentation process. Nitrogen limitation treatment resulted in a 65% increase of biogas yields for C. reinhardtii biomass (max. 698±23mL biogas g(-1) VS) when compared to replete conditions. For P. kessleri and S. obliquus, yields increased by 94% and 106% (max. 706±39mL and 586±36mL biogas g(-1) VS, respectively). From these results we conclude that this novel one-stage cultivation strategy with inherent nitrogen limitation can be used as a pretreatment for microalgal biomass generation, in order to produce accessible substrates with optimized C/N ratios for the subsequent anaerobic fermentation process, thus increasing methane production and avoiding the risk of ammonia inhibition effects within the fermenter. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. A novel microalgal system for energy production with nitrogen cycling

    Energy Technology Data Exchange (ETDEWEB)

    Minowa, T.; Sawayama, S. [National Institute for Resources and Environment, Tsukuba (Japan)

    1999-08-01

    A microalga, Chlorella vulgaris, could grow in the recovered solution from the low temperature catalytic gasification of itself, by which methane rich fuel gas was obtained. All nitrogen in the microalga was converted to ammonia during the gasification, and the recovered solution, in which ammonia was dissolved, could be used as nitrogen nutrient. The result of the energy evaluation indicated that the novel microalgal system for energy production with nitrogen cycling could be created. 9 refs., 3 tabs.

  14. Role of granular activated carbon in the microalgal cultivation from bacteria contamination.

    Science.gov (United States)

    Ni, Zhi-Yi; Li, Jing-Ya; Xiong, Zhao-Zhao; Cheng, Li-Hua; Xu, Xin-Hua

    2018-01-01

    Microalgal wastewater treatment has been considered as one of the most promising measures to treat nitrogen and phosphorus in the municipal wastewater. While the municipal wastewater provides sufficient nitrogen and phosphorus for microalgal growth, the microalgae still faces serious biological contamination caused by bacteria in wastewater. In this study, the commercial granular activated carbon (GAC) was added into the simulated municipal wastewater to avoid the influence of bacteria on the growth of microalgae. The extracellular organic matter (EOM) in microalgal broth was then characterized to enlighten the role of GAC in reducing the bioavailability of EOM. The results showed that the GAC addition could increase the dry weight of microalgae from 0.06mgL -1 to 0.46mgL -1 under the condition of bacterial inoculation. The GAC could mitigate bacterial contamination mainly due to its adsorption of both bacteria and EOM that might contain algicidal extracellular substances. Moreover, compared to the control group, the GAC addition could mitigate the microalgal lysis caused by bacteria and thus greatly reduce the bioavailability of EOM from 2.80mgL -1 to 0.61mgL -1 , which was beneficial for the improvement of biostability and reuse of effluent after the microalgal harvesting. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Modelling of green microalgal growth and algal storage processes using wastewater resources

    DEFF Research Database (Denmark)

    Wágner, Dorottya Sarolta; Plósz, Benedek G.; Valverde Pérez, Borja

    2017-01-01

    Recent research focuses on the recovery of nutrients, water and energy from wastewater. Microalgal cultivation on wastewater resources is considered as a more sustainable means to produce fertilizers or biofuels. Innovative systems that incorporate microalgal cultivation into conventional wastewa...... have been developed according to the activated sludge modelling (ASM) framework to facilitate the integration with existing modelling frameworks in water treatment. This chapter presents in detail the recently developed ASM-A biokinetic green microalgal process model. The model includes...

  16. Carbon Dioxide Sequestering Using Microalgal Systems

    Energy Technology Data Exchange (ETDEWEB)

    Daniel J. Stepan; Richard E. Shockey; Thomas A. Moe; Ryan Dorn

    2002-02-01

    This project evaluated key design criteria, the technical feasibility, and the preliminary economic viability of a CO{sub 2}-sequestering system integrated with a coal-fired power plant based on microalgae biofixation. A review of relevant literature was conducted, and a bench-scale algal-based sequestration system was constructed and operated to verify algal growth capabilities using a simulated flue gas stream. The bench-scale system was a 20-gallon glass aquarium with a 16-gallon operating volume and was direct-sparged with a simulated flue gas. The flue gas composition was based on flue gas analyses for a 550-MW Coal Creek Power Station boiler in Underwood, North Dakota, which averaged 12.1% CO{sub 2}, 5.5% O{sub 2}, 423 ppm SO{sub 2}, 124 ppm NO{sub x}, and an estimated 50 mg/m{sup 3} fly ash loading. The algae were grown in Bold's basal growth medium. Lighting was provided using a two-tube fluorescent ''grow-light'' bulb fixture mounted directly above the tank. Algal growth appeared to be inhibited in the presence of SO{sub 2} using mixed cultures of green and blue-green cultures of algae. Samples of Monoraphidium strain MONOR02 and Nannochloropsis NANNO02 algal samples were obtained from the University of Hawaii Culture Collection. These samples did not exhibit inhibited growth in the presence of all the simulated flue gas constituents, but growth rates were somewhat lower than those expected, based on the review of literature. Samples of harvested algae were analyzed for protein, lipid, and carbohydrate content. A lipid content of 26% appeared to be fairly normal for algae, and it did not appear that large amounts of nitrogen were being fixed and promoting growth, nor were the algae starved for nitrogen. Proteins made up 41% of the total mass, and carbohydrates were assumed to be 33% (by difference). A preliminary economic analysis showed the costs of an integrated system based on microalgae biofixation to sequester 25% of the CO

  17. Repeated batch cultivation of the hydrocarbon-degrading, micro-algal strain Prototheca zopfii RND16 immobilized in polyurethane foam.

    Science.gov (United States)

    Ueno, Ryohei; Wada, Shun; Urano, Naoto

    2008-01-01

    This study reports on the stability of the cells of a heterotrophic green micro-algal strain Prototheca zopfii RND16 immobilized in polyurethane foam (PUF) cubes during degradation of mixed hydrocarbon substrate, which was composed of n-alkanes and polycyclic aromatic hydrocarbons (PAHs), in 5 successive cycles of repeated batch cultivation at 30 degrees C. Both RND16 cells and mixed hydrocarbon substrate components had been entrapped in PUF cubes through cultivation. PUF-immobilized RND16 degraded n-alkanes almost completely, whereas the strain hardly degraded PAHs in PUFs, rather they accumulated in the matrices. It is noteworthy that this result is strikingly different from that of the free-living cell culture, where RND16 reduced concentrations of both n-alkanes and PAHs. However, PAHs accumulation in the PUFs did not impair the performance of the immobilized alga to utilize n-alkanes. These results suggest that the PUFs harboring RND16 cells could be used repeatedly for selective retrieval of PAHs from oil-polluted waters after preferential biodegradation of n-alkanes by algae.

  18. Resource Assessment for Microalgal/Emergent Aquatic Biomass Systems in the Arid Southwest: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Vigon, B. W.; Arthur, M. F.; Taft, L. G.; Wagner, C. K.; Lipinsky, E. S.; Litchfield, J. H.; McCandlish, C. D.; Clark, R.

    1982-12-23

    This research project has been designed to facilitate the eventual selection of biomass production systems using aquatic species (microalgal and emergent aquatic plant species (MEAP) which effectively exploit the potentially available resources of the Southwest.

  19. Biofilm based attached cultivation technology for microalgal biorefineries-A review.

    Science.gov (United States)

    Wang, Junfeng; Liu, Wen; Liu, Tianzhong

    2017-11-01

    The attached cultivation for microalga has many superiorities over the conventional aqua-suspend methods, which make it a promising pathway to supply feedstock for microalgae based bio-refinery attempts. In this review, the current reports on bioreactor, application, modeling, substratum material and engineering aspects were summarized and the future research and developments should be focused on the following aspects: 1) Build principles and guidelines for rational structure design by studying the relationship of physiological properties with typical structures and light regimes; 2) Set up theory foundation of substratum material selection by studying the physic-chemical properties of algal cells and substratum materials; 3) Further understanding the mass transfer behaviors of both CO 2 and nutrients in biofilm for enhanced growth rate and products accumulation; 4) New equipment and machines for inoculation, harvesting and moisture keeping should be developed and integrated with bioreactor structure. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Continuous microalgal cultivation in a laboratory-scale photobioreactor under seasonal day-night irradiation: experiments and simulation.

    Science.gov (United States)

    Bertucco, Alberto; Beraldi, Mariaelena; Sforza, Eleonora

    2014-08-01

    In this work, the production of Scenedesmus obliquus in a continuous flat-plate laboratory-scale photobioreactor (PBR) under alternated day-night cycles was tested both experimentally and theoretically. Variation of light intensity according to the four seasons of the year were simulated experimentally by a tunable LED lamp, and effects on microalgal growth and productivity were measured to evaluate the conversion efficiency of light energy into biomass during the different seasons. These results were used to validate a mathematical model for algae growth that can be applied to simulate a large-scale production unit, carried out in a flat-plate PBR of similar geometry. The cellular concentration in the PBR was calculated in both steady-state and transient conditions, and the value of the maintenance kinetic term was correlated to experimental profiles. The relevance of this parameter was finally outlined.

  1. A comparative study of soft sensor design for lipid estimation of microalgal photobioreactor system with experimental validation.

    Science.gov (United States)

    Yoo, Sung Jin; Jung, Dong Hwi; Kim, Jung Hun; Lee, Jong Min

    2015-03-01

    This study examines the applicability of various nonlinear estimators for online estimation of the lipid concentration in microalgae cultivation system. Lipid is a useful bio-product that has many applications including biofuels and bioactives. However, the improvement of lipid productivity using real-time monitoring and control with experimental validation is limited because measurement of lipid in microalgae is a difficult and time-consuming task. In this study, estimation of lipid concentration from other measurable sources such as biomass or glucose sensor was studied. Extended Kalman filter (EKF), unscented Kalman filter (UKF), and particle filter (PF) were compared in various cases for their applicability to photobioreactor systems. Furthermore, simulation studies to identify appropriate types of sensors for estimating lipid were also performed. Based on the case studies, the most effective case was validated with experimental data and found that UKF and PF with time-varying system noise covariance is effective for microalgal photobioreactor system. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. EBP2R – An innovative enhanced biological nutrient recovery activated sludge system to produce growth medium for green microalgae cultivation

    DEFF Research Database (Denmark)

    Valverde Perez, Borja; Ramin, Elham; Smets, Barth F.

    2015-01-01

    system to produce nutrient rich organic-carbon depleted algal cultivation media of target composition. Via SRT control, the quality of the constructed cultivation media can be optimized to support a wide range of green micro-algal growth requirements. Up to 75% of the influent phosphorus can be recovered...... that the system performance predicted through the model-based design can be achieved in reality....

  3. Biodiesel production by microalgal biotechnology

    Energy Technology Data Exchange (ETDEWEB)

    Huang, GuanHua [School of Chemical Engineering and Technology, China University of Mining and Technology (China); Chen, Feng [School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong (China); College of Light Industry and Food Sciences, South China University of Technology, Guangzhou (China); Wei, Dong; Zhang, XueWu; Chen, Gu [College of Light Industry and Food Sciences, South China University of Technology, Guangzhou (China)

    2010-01-15

    Biodiesel has received much attention in recent years. Although numerous reports are available on the production of biodiesel from vegetable oils of terraneous oil-plants, such as soybean, sunflower and palm oils, the production of biodiesel from microalgae is a newly emerging field. Microalgal biotechnology appears to possess high potential for biodiesel production because a significant increase in lipid content of microalgae is now possible through heterotrophic cultivation and genetic engineering approaches. This paper provides an overview of the technologies in the production of biodiesel from microalgae, including the various modes of cultivation for the production of oil-rich microalgal biomass, as well as the subsequent downstream processing for biodiesel production. The advances and prospects of using microalgal biotechnology for biodiesel production are discussed. (author)

  4. Development of an attached microalgal growth system for biofuel production.

    Science.gov (United States)

    Johnson, Michael B; Wen, Zhiyou

    2010-01-01

    Algal biofuel production has gained a renewed interest in recent years but is still not economically feasible due to several limitations related to algal culture. The objective of this study is to explore a novel attached culture system for growing the alga Chlorella sp. as biodiesel feedstock, with dairy manure wastewater being used as growth medium. Among supporting materials tested for algal attachment, polystyrene foam led to a firm attachment, high biomass yield (25.65 g/m(2), dry basis), and high fatty acid yield (2.31 g/m(2)). The biomass attached on the supporting material surface was harvested by scraping; the residual colonies left on the surface served as inoculum for regrowth. The algae regrowth on the colony-established surface resulted in a higher biomass yield than that from the initial growth on fresh surface due to the downtime saved for initial algal attachment. The 10-day regrowth culture resulted in a high biodiesel production potential with a fatty acid methyl esters yield of 2.59 g/m(2) and a productivity of 0.26 g/m(-2) day(-1). The attached algal culture also removed 61-79% total nitrogen and 62-93% total phosphorus from dairy manure wastewater, depending on different culture conditions. The biomass harvested from the attached growth system (through scraping) had a water content of 93.75%, similar to that harvested from suspended culture system (through centrifugation). Collectively, the attached algal culture system with polystyrene foam as a supporting material demonstrated a good performance in terms of biomass yield, biodiesel production potential, ease to harvest biomass, and physical robustness for reuse.

  5. Nutrient removal and biomass production: advances in microalgal biotechnology for wastewater treatment.

    Science.gov (United States)

    Abinandan, Sudharsanam; Subashchandrabose, Suresh R; Venkateswarlu, Kadiyala; Megharaj, Mallavarapu

    2018-05-17

    Owing to certain drawbacks, such as energy-intensive operations in conventional modes of wastewater treatment (WWT), there has been an extensive search for alternative strategies in treatment technology. Biological modes for treating wastewaters are one of the finest technologies in terms of economy and efficiency. An integrated biological approach with chemical flocculation is being conventionally practiced in several-sewage and effluent treatment plants around the world. Overwhelming responsiveness to treat wastewaters especially by using microalgae is due to their simplest photosynthetic mechanism and ease of acclimation to various habitats. Microalgal technology, also known as phycoremediation, has been in use for WWT since 1950s. Various strategies for the cultivation of microalgae in WWT systems are evolving faster. However, the availability of innovative approaches for maximizing the treatment efficiency, coupled with biomass productivity, remains the major bottleneck for commercialization of microalgal technology. Investment costs and invasive parameters also delimit the use of microalgae in WWT. This review critically discusses the merits and demerits of microalgal cultivation strategies recently developed for maximum pollutant removal as well as biomass productivity. Also, the potential of algal biofilm technology in pollutant removal, and harvesting the microalgal biomass using different techniques have been highlighted. Finally, an economic assessment of the currently available methods has been made to validate microalgal cultivation in wastewater at the commercial level.

  6. Perspectives of microalgal biofuels as a renewable source of energy

    International Nuclear Information System (INIS)

    Kiran, Bala; Kumar, Ritunesh; Deshmukh, Devendra

    2014-01-01

    Highlights: • Microalgae offer solution of wastewater treatment, CO 2 sequestration, and energy crises. • Microalgal biofuel is renewable, nontoxic and environmentally friendly option. • Integration of wastewater treatment with biofuels production has made them more cost effective. • This article details out the potential production process and benefits of microalgal biofuels. - Abstract: Excessive use of fossil fuels to satisfy our rapidly increasing energy demand has created severe environmental problems, such as air pollution, acid rain and global warming. Biofuels are a potential alternative to fossil fuels. First- and second-generation biofuels face criticism due to food security and biodiversity issues. Third-generation biofuels, based on microalgae, seem to be a plausible solution to the current energy crisis, as their oil-producing capability is many times higher than that of various oil crops. Microalgae are the fastest-growing plants and can serve as a sustainable energy source for the production of biodiesel and several other biofuels by conversion of sunlight into chemical energy. Biofuels produced from microalgae are renewable, non-toxic, biodegradable and environment friendly. Microalgae can be grown in open pond systems or closed photobioreactors. Microalgal biofuels are a potential means to keep the development of human activities in synchronization with the environment. The integration of wastewater treatment with biofuel production using microalgae has made microalgal biofuels more attractive and cost effective. A biorefinery approach can also be used to improve the economics of biofuel production, in which all components of microalgal biomass (i.e., proteins, lipids and carbohydrates) are used to produce useful products. The integration of various processes for maximum economic and environmental benefits minimizes the amount of waste produced and the pollution level. This paper presents an overview of various aspects associated with

  7. Microalgal lipids biochemistry and biotechnological perspectives.

    Science.gov (United States)

    Bellou, Stamatia; Baeshen, Mohammed N; Elazzazy, Ahmed M; Aggeli, Dimitra; Sayegh, Fotoon; Aggelis, George

    2014-12-01

    . Therefore, algal production systems need to be improved and harvesting systems need to be more effective in order for their industrial applications to become more competitive and economically viable. Besides, a reduction of the production cost of microalgal lipids can be achieved by combining lipid production with other commercial applications. The combined production of bioactive products and lipids, when possible, can support the commercial viability of both processes. Hydrophobic compounds can be extracted simultaneously with lipids and then purified, while hydrophilic compounds such as proteins and sugars may be extracted from the defatted biomass. The microalgae also have applications in environmental biotechnology since they can be used for bioremediation of wastewater and to monitor environmental toxicants. Algal biomass produced during wastewater treatment may be further valorized in the biofuel manufacture. It is anticipated that the high microalgal lipid potential will force research towards finding effective ways to manipulate biochemical pathways involved in lipid biosynthesis and towards cost effective algal cultivation and harvesting systems, as well. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Soilless cultivation system for functional food crops

    International Nuclear Information System (INIS)

    Ahamad Sahali Mardi; Shyful Azizi Abdul Rahman; Ahmad Nazrul Abd Wahid; Abdul Razak Ruslan; Hazlina Abdullah

    2007-01-01

    This soilless cultivation system is based on the fertigation system and cultivation technologies using Functional Plant Cultivation System (FPCS). EBARA Japan has been studying on the cultivation conditions in order to enhance the function of decease risk reduction in plants. Through the research and development activities, EBARA found the possibilities on the enhancement of functions. Quality and quantity of the products in term of bioactive compounds present in the plants may be affected by unforeseen environmental conditions, such as temperature, strong light and UV radiation. The main objective to develop this system is, to support? Functional Food Industry? as newly emerging field in agriculture business. To success the system, needs comprehensive applying agriculture biotechnologies, health biotechnologies and also information technologies, in agriculture. By this system, production of valuable bioactive compounds is an advantage, because the market size of functional food is increasing more and more in the future. (Author)

  9. Microalgal production - A close look at the economics

    NARCIS (Netherlands)

    Norsker, N.H.; Barbosa, M.J.; Vermuë, M.H.; Wijffels, R.H.

    2011-01-01

    Worldwide, microalgal biofuel production is being investigated. It is strongly debated which type of production technology is the most adequate. Microalgal biomass production costs were calculated for 3 different micro algal production systems operating at commercial scale today: open ponds,

  10. Integration of microalgae cultivation with industrial waste remediation for biofuel and bioenergy production: opportunities and limitations.

    Science.gov (United States)

    McGinn, Patrick J; Dickinson, Kathryn E; Bhatti, Shabana; Frigon, Jean-Claude; Guiot, Serge R; O'Leary, Stephen J B

    2011-09-01

    There is currently a renewed interest in developing microalgae as a source of renewable energy and fuel. Microalgae hold great potential as a source of biomass for the production of energy and fungible liquid transportation fuels. However, the technologies required for large-scale cultivation, processing, and conversion of microalgal biomass to energy products are underdeveloped. Microalgae offer several advantages over traditional 'first-generation' biofuels crops like corn: these include superior biomass productivity, the ability to grow on poor-quality land unsuitable for agriculture, and the potential for sustainable growth by extracting macro- and micronutrients from wastewater and industrial flue-stack emissions. Integrating microalgal cultivation with municipal wastewater treatment and industrial CO(2) emissions from coal-fired power plants is a potential strategy to produce large quantities of biomass, and represents an opportunity to develop, test, and optimize the necessary technologies to make microalgal biofuels more cost-effective and efficient. However, many constraints on the eventual deployment of this technology must be taken into consideration and mitigating strategies developed before large scale microalgal cultivation can become a reality. As a strategy for CO(2) biomitigation from industrial point source emitters, microalgal cultivation can be limited by the availability of land, light, and other nutrients like N and P. Effective removal of N and P from municipal wastewater is limited by the processing capacity of available microalgal cultivation systems. Strategies to mitigate against the constraints are discussed.

  11. Comparison of Microalgae Cultivation in Photobioreactor, Open Raceway Pond, and a Two-Stage Hybrid System

    Energy Technology Data Exchange (ETDEWEB)

    Narala, Rakesh R.; Garg, Sourabh; Sharma, Kalpesh K.; Thomas-Hall, Skye R.; Deme, Miklos; Li, Yan; Schenk, Peer M., E-mail: p.schenk@uq.edu.au [Algae Biotechnology Laboratory, School of Agriculture and Food Sciences, The University of Queensland, Brisbane, QLD (Australia)

    2016-08-02

    In the wake of intensive fossil fuel usage and CO{sub 2} accumulation in the environment, research is targeted toward sustainable alternate bioenergy that can suffice the growing need for fuel and also that leaves a minimal carbon footprint. Oil production from microalgae can potentially be carried out more efficiently, leaving a smaller footprint and without competing for arable land or biodiverse landscapes. However, current algae cultivation systems and lipid induction processes must be significantly improved and are threatened by contamination with other algae or algal grazers. To address this issue, we have developed an efficient two-stage cultivation system using the marine microalga Tetraselmis sp. M8. This hybrid system combines exponential biomass production in positive pressure air lift-driven bioreactors with a separate synchronized high-lipid induction phase in nutrient deplete open raceway ponds. A comparison to either bioreactor or open raceway pond cultivation system suggests that this process potentially leads to significantly higher productivity of algal lipids. Nutrients are only added to the closed bioreactors, while open raceway ponds have turnovers of only a few days, thus reducing the issue of microalgal grazers.

  12. Comparison of microalgae cultivation in photobioreactor, open raceway pond, and a two-stage hybrid system

    Directory of Open Access Journals (Sweden)

    Rakesh R Narala

    2016-08-01

    Full Text Available In the wake of intensive fossil fuel usage and CO2 accumulation in the environment, research is targeted towards sustainable alternate bioenergy that can suffice the growing need for fuel and also that leaves a minimal carbon footprint. Oil production from microalgae can potentially be carried out more efficiently, leaving a smaller footprint and without competing for arable land or biodiverse landscapes. However, current algae cultivation systems and lipid induction processes must be significantly improved and are threatened by contamination with other algae or algal grazers. To address this issue, we have developed an efficient two-stage cultivation system using the marine microalga Tetraselmis sp. M8. This hybrid system combines exponential biomass production in positive pressure air lift-driven bioreactors with a separate synchronized high-lipid induction phase in nutrient deplete open raceway ponds. A comparison to either bioreactor or open raceway pond cultivation system suggests that this process potentially leads to significantly higher productivity of algal lipids. Nutrients are only added to the closed bioreactors while open raceway ponds have turnovers of only a few days, thus reducing the issue of microalgal grazers.

  13. Comparison of Microalgae Cultivation in Photobioreactor, Open Raceway Pond, and a Two-Stage Hybrid System

    International Nuclear Information System (INIS)

    Narala, Rakesh R.; Garg, Sourabh; Sharma, Kalpesh K.; Thomas-Hall, Skye R.; Deme, Miklos; Li, Yan; Schenk, Peer M.

    2016-01-01

    In the wake of intensive fossil fuel usage and CO 2 accumulation in the environment, research is targeted toward sustainable alternate bioenergy that can suffice the growing need for fuel and also that leaves a minimal carbon footprint. Oil production from microalgae can potentially be carried out more efficiently, leaving a smaller footprint and without competing for arable land or biodiverse landscapes. However, current algae cultivation systems and lipid induction processes must be significantly improved and are threatened by contamination with other algae or algal grazers. To address this issue, we have developed an efficient two-stage cultivation system using the marine microalga Tetraselmis sp. M8. This hybrid system combines exponential biomass production in positive pressure air lift-driven bioreactors with a separate synchronized high-lipid induction phase in nutrient deplete open raceway ponds. A comparison to either bioreactor or open raceway pond cultivation system suggests that this process potentially leads to significantly higher productivity of algal lipids. Nutrients are only added to the closed bioreactors, while open raceway ponds have turnovers of only a few days, thus reducing the issue of microalgal grazers.

  14. Growth and biomass productivity of Scenedesmus vacuolatus on a twin layer system and a comparison with other types of cultivations.

    Science.gov (United States)

    Carbone, Dora Allegra; Olivieri, Giuseppe; Pollio, Antonino; Gabriele; Melkonian, Michael

    2017-12-01

    Scenedesmus is a genus of microalgae employed for several industrial uses. Industrial cultivations are performed in open ponds or in closed photobioreactors (PBRs). In the last years, a novel type of PBR based on immobilized microalgae has been developed termed porous substrate photobioreactors (PSBR) to achieve significant higher biomass density during cultivation in comparison to classical PBRs. This work presents a study of the growth of Scenedesmus vacuolatus in a Twin Layer System PSBR at different light intensities (600 μmol photons m -2  s -1 or 1000 μmol photons m -2  s -1 ), different types and concentrations of the nitrogen sources (nitrate or urea), and at two CO 2 levels in the gas phase (2% or 0.04% v/v). The microalgal growth was followed by monitoring the attached biomass density as dry weight, the specific growth rate and pigment accumulation. The highest productivity (29 g m -2 d -1 ) was observed at a light intensity of 600 μmol photons m -2  s -1 and 2% CO 2 . The types and concentrations of nitrogen sources did not influence the biomass productivity. Instead, the higher light intensity of 1000 μmol photons m -2  s -1 and an ambient CO 2 concentration (0.04%) resulted in a significant decrease of productivity to 18 and 10-12 g m -2 d -1 , respectively. When compared to the performance of similar cultivation systems (15-30 g m -2 d -1 ), these results indicate that the Twin Layer cultivation System is a competitive technique for intensified microalgal cultivation in terms of productivity and, at the same time, biomass density.

  15. Microalgae for high-value compounds and biofuels production: a review with focus on cultivation under stress conditions.

    Science.gov (United States)

    Markou, Giorgos; Nerantzis, Elias

    2013-12-01

    Microalgal biomass as feedstock for biofuel production is an attracting alternative to terrestrial plant utilization for biofuels production. However, today the microalgal cultivation systems for energy production purposes seem not yet to be economically feasible. Microalgae, though cultivated under stress conditions, such as nutrient starvation, high salinity, high temperature etc. accumulate considerable amounts (up to 60-65% of dry weight) of lipids or carbohydrates along with several secondary metabolites. Especially some of the latter are valuable compounds with an enormous range of industrial applications. The simultaneous production of lipids or carbohydrates for biofuel production and of secondary metabolites in a biorefinery concept might allow the microalgal production to be economically feasible. This paper aims to provide a review on the available literature about the cultivation of microalgae for the accumulation of high-value compounds along with lipids or carbohydrates focusing on stress cultivation conditions. © 2013.

  16. Energy analysis and environmental impacts of microalgal biodiesel in China

    International Nuclear Information System (INIS)

    Liao Yanfen; Huang Zehao; Ma Xiaoqian

    2012-01-01

    The entire life cycle of biodiesel produced by microalgal biomasses was evaluated using the method of life cycle assessment (LCA) to identify and quantify the fossil energy requirements and environmental impact loading of the system. The life cycle considers microalgae cultivation, harvesting, drying, oil extraction, anaerobic digestion, oil transportation, esterification, biodiesel transportation and biodiesel combustion. The investigation results show that the fossil energy requirement for the biodiesel production is 0.74 MJ/MJ biodiesel, indicating that 1 MJ of biodiesel requires an input of 0.74 MJ of fossil energy. Accordingly, biodiesel production is feasible as an energy producing process. The environmental impact loading of microalgal biodiesel is 3.69 PET 2010 (Person Equivalents, Targeted, in 2010) and the GWP is 0.16 kg CO 2-eq /MJ biodiesel. The effects of photochemical ozone formation were greatest among all calculated categorization impacts. The fossil energy requirement and GWP in this operation were found to be particularly sensitive to oil content, drying rate and esterification rate. Overall, the results presented herein indicate that the cultivation of microalgae has the potential to produce an environmentally sustainable feedstock for the production of biodiesel. - Highlights: ► Do energy analysis and environmental impacts of algal biodiesel in China. ► GWP and energy consumption are sensitive to lipid content and drying rate. ► Fossil energy consumption for algal biodiesel is 0.74 MJ/MJ. ► Microalgae are an environmentally sustainable feedstock for biodiesel production.

  17. SIMULATION OF MICROALGAL GROWTH IN A CONTINUOUS PHOTOBIOREACTOR WITH SEDIMENTATION AND PARTIAL BIOMASS RECYCLING

    Directory of Open Access Journals (Sweden)

    C. E. de Farias Silva

    Full Text Available Abstract Microalgae are considered as promising feedstocks for the third generation of biofuels. They are autotrophic organisms with high growth rate and can stock an enormous quantity of lipids (about 20 - 40% of their dried cellular weight. This work was aimed at studying the cultivation of Scenedesmus obliquus in a two-stage system composed of a photobioreactor and a settler to concentrate and partially recycle the biomass as a way to enhance the microalgae cellular productivity. It was attempted to specify by simulation and experimental data a relationship between the recycling rate, kinetic parameters of microalgal growth and photobioreactor operating conditions. Scenedesmus obliquus cells were cultivated in a lab-scale flat-plate reactor, homogenized by aeration, and running in continuous flow with a residence time of 1.66 day. Experimental data for the microalgal growth were used in a semi-empirical simulation model. The best results were obtained for Fw=0.2FI, when R = 1 and kd = 0 and 0.05 day-1, with the biomass production in the reactor varying between 8 g L -1 and 14 g L-1, respectively. The mathematical model fitted to the microalgal growth experimental data was appropriate for predicting the efficiency of the reactor in producing Scenedesmus obliquus cells, establishing a relation between cellular productivity and the minimum recycling rate that must be used in the system.

  18. Microalgal Culture Collection Transfers

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Milford Microalgal culture Collection holds over 200 live cultures representing 13 classes of of algae. The cultures are maintained in three different growing...

  19. EBP2R - an innovative enhanced biological nutrient recovery activated sludge system to produce growth medium for green microalgae cultivation.

    Science.gov (United States)

    Valverde-Pérez, Borja; Ramin, Elham; Smets, Barth F; Plósz, Benedek Gy

    2015-01-01

    Current research considers wastewater as a source of energy, nutrients and water and not just a source of pollution. So far, mainly energy intensive physical and chemical unit processes have been developed to recover some of these resources, and less energy and resource demanding alternatives are needed. Here, we present a modified enhanced biological phosphorus removal and recovery system (referred to as EBP2R) that can produce optimal culture media for downstream micro-algal growth in terms of N and P content. Phosphorus is recovered as a P-stream by diversion of some of the effluent from the upstream anaerobic reactor. By operating the process at comparably low solids retention times (SRT), the nitrogen content of wastewater is retained as free and saline ammonia, the preferred form of nitrogen for most micro-algae. Scenario simulations were carried out to assess the capacity of the EBP2R system to produce nutrient rich organic-carbon depleted algal cultivation media of target composition. Via SRT control, the quality of the constructed cultivation media can be optimized to support a wide range of green micro-algal growth requirements. Up to 75% of the influent phosphorus can be recovered, by diverting 30% of the influent flow as a P-stream at an SRT of 5 days. Through global sensitivity analysis we find that the effluent N-to-P ratio and the P recovered are mainly dependent on the influent quality rather than on biokinetics or stoichiometry. Further research is needed to demonstrate that the system performance predicted through the model-based design can be achieved in reality. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Advanced continuous cultivation methods for systems microbiology.

    Science.gov (United States)

    Adamberg, Kaarel; Valgepea, Kaspar; Vilu, Raivo

    2015-09-01

    Increasing the throughput of systems biology-based experimental characterization of in silico-designed strains has great potential for accelerating the development of cell factories. For this, analysis of metabolism in the steady state is essential as only this enables the unequivocal definition of the physiological state of cells, which is needed for the complete description and in silico reconstruction of their phenotypes. In this review, we show that for a systems microbiology approach, high-resolution characterization of metabolism in the steady state--growth space analysis (GSA)--can be achieved by using advanced continuous cultivation methods termed changestats. In changestats, an environmental parameter is continuously changed at a constant rate within one experiment whilst maintaining cells in the physiological steady state similar to chemostats. This increases the resolution and throughput of GSA compared with chemostats, and, moreover, enables following of the dynamics of metabolism and detection of metabolic switch-points and optimal growth conditions. We also describe the concept, challenge and necessary criteria of the systematic analysis of steady-state metabolism. Finally, we propose that such systematic characterization of the steady-state growth space of cells using changestats has value not only for fundamental studies of metabolism, but also for systems biology-based metabolic engineering of cell factories.

  1. Changes in shifting cultivation systems on small Pacific islands

    DEFF Research Database (Denmark)

    Mertz, Ole; Birch-Thomsen, Torben; Elberling, Bo

    2012-01-01

    The limited information on change in shifting cultivation systems of small islands of the Pacific stands in contrast to increasing evidence of this farming system's demise in other parts of the tropics. Here, we assess changes in agricultural activities during the past 40 years of Bellona Island......, Solomon Islands, where shifting cultivation is still maintained in the traditional way. Fallow length has increased despite population growth due to redistribution of the cultivated area, migration-induced extensification and changes in crops. Productivity of the farming system remains high although...

  2. Mixotrophic cultivation of microalgae for biodiesel production: status and prospects.

    Science.gov (United States)

    Wang, Jinghan; Yang, Haizhen; Wang, Feng

    2014-04-01

    Biodiesel from microalgae provides a promising alternative for biofuel production. Microalgae can be produced under three major cultivation modes, namely photoautotrophic cultivation, heterotrophic cultivation, and mixotrophic cultivation. Potentials and practices of biodiesel production from microalgae have been demonstrated mostly focusing on photoautotrophic cultivation; mixotrophic cultivation of microalgae for biodiesel production has rarely been reviewed. This paper summarizes the mechanisms and virtues of mixotrophic microalgae cultivation through comparison with other major cultivation modes. Influencing factors of microalgal biodiesel production under mixotrophic cultivation are presented, development of combining microalgal biodiesel production with wastewater treatment is especially reviewed, and bottlenecks and strategies for future commercial production are also identified.

  3. Modeling of microalgal metabolism

    NARCIS (Netherlands)

    Kliphuis, A.M.J.

    2010-01-01

    Microalgae are a potential source for a wide range of products, such as carotenoids, lipids, hydrogen, protein and starch, which are of interest for food, feed and biofuel applications. Maximization of microalgal product and biomass productivity in (large-scale) outdoor photobioreactors is important

  4. BILINEAR SYSTEM AS A MODELLING FRAMEWORK FOR ANALYSIS OF MICROALGAL GROWTH

    Czech Academy of Sciences Publication Activity Database

    Papáček, Š.; Čelikovský, Sergej; Štys, D.; Ruiz León, J.

    2007-01-01

    Roč. 43, č. 1 (2007), s. 1-20 ISSN 0023-5954 R&D Projects: GA ČR GA102/05/0011 Institutional research plan: CEZ:AV0Z10750506 Keywords : bilinear system * model of photosynthetic factory * microalgae * light/dark cycles * flashing light experiments Subject RIV: BC - Control Systems Theory Impact factor: 0.552, year: 2007

  5. Biomek Cell Workstation: A Variable System for Automated Cell Cultivation.

    Science.gov (United States)

    Lehmann, R; Severitt, J C; Roddelkopf, T; Junginger, S; Thurow, K

    2016-06-01

    Automated cell cultivation is an important tool for simplifying routine laboratory work. Automated methods are independent of skill levels and daily constitution of laboratory staff in combination with a constant quality and performance of the methods. The Biomek Cell Workstation was configured as a flexible and compatible system. The modified Biomek Cell Workstation enables the cultivation of adherent and suspension cells. Until now, no commercially available systems enabled the automated handling of both types of cells in one system. In particular, the automated cultivation of suspension cells in this form has not been published. The cell counts and viabilities were nonsignificantly decreased for cells cultivated in AutoFlasks in automated handling. The proliferation of manual and automated bioscreening by the WST-1 assay showed a nonsignificant lower proliferation of automatically disseminated cells associated with a mostly lower standard error. The disseminated suspension cell lines showed different pronounced proliferations in descending order, starting with Jurkat cells followed by SEM, Molt4, and RS4 cells having the lowest proliferation. In this respect, we successfully disseminated and screened suspension cells in an automated way. The automated cultivation and dissemination of a variety of suspension cells can replace the manual method. © 2015 Society for Laboratory Automation and Screening.

  6. Closing the water and nutrient cycles in soilless cultivation systems

    NARCIS (Netherlands)

    Beerling, E.A.M.; Blok, C.; Maas, van der A.A.; Os, van E.A.

    2014-01-01

    Soilless cultivation systems are common in Dutch greenhouse horticulture, i.e., less than 20% of the greenhouse area is still soil grown. For long, it was assumed that in these so-called closed systems the emission of nutrients and plant protection products (PPPs) was close to zero. However, Water

  7. Microalgal biofilms for wastewater treatment

    NARCIS (Netherlands)

    Boelee, N.C.

    2013-01-01

    The objective of this thesis was to explore the possibilities of using microalgal biofilms for the treatment of municipal wastewater, with a focus on the post-treatment of municipal wastewater effluent. The potential of microalgal biofilms for wastewater treatment was first investigated using a

  8. Progress and Challenges in Microalgal Biodiesel Production

    Science.gov (United States)

    Mallick, Nirupama; Bagchi, Sourav K.; Koley, Shankha; Singh, Akhilesh K.

    2016-01-01

    The last decade has witnessed a tremendous impetus on biofuel research due to the irreversible diminution of fossil fuel reserves for enormous demands of transportation vis-a-vis escalating emissions of green house gasses (GHGs) into the atmosphere. With an imperative need of CO2 reduction and considering the declining status of crude oil, governments in various countries have not only diverted substantial funds for biofuel projects but also have introduced incentives to vendors that produce biofuels. Currently, biodiesel production from microalgal biomass has drawn an immense importance with the potential to exclude high-quality agricultural land use and food safe-keeping issues. Moreover, microalgae can grow in seawater or wastewater and microalgal oil can exceed 50–60% (dry cell weight) as compared with some best agricultural oil crops of only 5–10% oil content. Globally, microalgae are the highest biomass producers and neutral lipid accumulators contending any other terrestrial oil crops. However, there remain many hurdles in each and every step, starting from strain selection and lipid accumulation/yield, algae mass cultivation followed by the downstream processes such as harvesting, drying, oil extraction, and biodiesel conversion (transesterification), and overall, the cost of production. Isolation and screening of oleaginous microalgae is one pivotal important upstream factor which should be addressed according to the need of freshwater or marine algae with a consideration that wild-type indigenous isolate can be the best suited for the laboratory to large scale exploitation. Nowadays, a large number of literature on microalgal biodiesel production are available, but none of those illustrate a detailed step-wise description with the pros and cons of the upstream and downstream processes of biodiesel production from microalgae. Specifically, harvesting and drying constitute more than 50% of the total production costs; however, there are quite a less

  9. Ecotoxicological effects of enrofloxacin and its removal by monoculture of microalgal species and their consortium.

    Science.gov (United States)

    Xiong, Jiu-Qiang; Kurade, Mayur B; Jeon, Byong-Hun

    2017-07-01

    Enrofloxacin (ENR), a fluoroquinolone antibiotic, has gained big scientific concern due to its ecotoxicity on aquatic microbiota. The ecotoxicity and removal of ENR by five individual microalgae species and their consortium were studied to correlate the behavior and interaction of ENR in natural systems. The individual microalgal species (Scenedesmus obliquus, Chlamydomonas mexicana, Chlorella vulgaris, Ourococcus multisporus, Micractinium resseri) and their consortium could withstand high doses of ENR (≤1 mg L -1 ). Growth inhibition (68-81%) of the individual microalgae species and their consortium was observed in ENR (100 mg L -1 ) compared to control after 11 days of cultivation. The calculated 96 h EC 50 of ENR for individual microalgae species and microalgae consortium was 9.6-15.0 mg ENR L -1 . All the microalgae could recover from the toxicity of high concentrations of ENR during cultivation. The biochemical characteristics (total chlorophyll, carotenoid, and malondialdehyde) were significantly influenced by ENR (1-100 mg L -1 ) stress. The individual microalgae species and microalgae consortium removed 18-26% ENR at day 11. Although the microalgae consortium showed a higher sensitivity (with lower EC 50 ) toward ENR than the individual microalgae species, the removal efficiency of ENR by the constructed microalgae consortium was comparable to that of the most effective microalgal species. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Microalgal biomass production pathways: evaluation of life cycle environmental impacts.

    Science.gov (United States)

    Zaimes, George G; Khanna, Vikas

    2013-06-20

    Microalgae are touted as an attractive alternative to traditional forms of biomass for biofuel production, due to high productivity, ability to be cultivated on marginal lands, and potential to utilize carbon dioxide (CO2) from industrial flue gas. This work examines the fossil energy return on investment (EROIfossil), greenhouse gas (GHG) emissions, and direct Water Demands (WD) of producing dried algal biomass through the cultivation of microalgae in Open Raceway Ponds (ORP) for 21 geographic locations in the contiguous United States (U.S.). For each location, comprehensive life cycle assessment (LCA) is performed for multiple microalgal biomass production pathways, consisting of a combination of cultivation and harvesting options. Results indicate that the EROIfossil for microalgae biomass vary from 0.38 to 1.08 with life cycle GHG emissions of -46.2 to 48.9 (g CO2 eq/MJ-biomass) and direct WDs of 20.8 to 38.8 (Liters/MJ-biomass) over the range of scenarios analyzed. Further anaylsis reveals that the EROIfossil for production pathways is relatively location invariant, and that algae's life cycle energy balance and GHG impacts are highly dependent on cultivation and harvesting parameters. Contrarily, algae's direct water demands were found to be highly sensitive to geographic location, and thus may be a constraining factor in sustainable algal-derived biofuel production. Additionally, scenarios with promising EROIfossil and GHG emissions profiles are plagued with high technological uncertainty. Given the high variability in microalgae's energy and environmental performance, careful evaluation of the algae-to-fuel supply chain is necessary to ensure the long-term sustainability of emerging algal biofuel systems. Alternative production scenarios and technologies may have the potential to reduce the critical demands of biomass production, and should be considered to make algae a viable and more efficient biofuel alternative.

  11. Dependence of carbon dioxide concentration on microalgal carbon dioxide fixation

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Yeoung Sang; Park, Song Moon [Department of Chemical Engineering, School of Environmental Engineering, Pohang University of Science and Technology, Pohang (Korea); Bolesky, Bohumil [Department of Chemical Engineering, McGill University (Canada)

    1999-10-01

    Batch cultivation of chlorella vulgaris was carried out under various CO{sub 2} concentrations in order to understand and describe mathematically the CO{sub 2} inhibition of microalgal CO{sub 2} fixation. The volumetric CO{sub 2} transfer coefficient from mixture gas to culture medium was estimated from the volumetric O{sub 2} transfer coefficient obtained experimentally. Using this transfer coefficient and aquatic equilibrium relationship between dissolved inorganic carbons, the behavior of dissolved CO{sub 2} was calculated during microalgal culture. When air containing 0.035%(v/v) CO{sub 2} was supplied into microalgal culture, the fixation rate was limited by CO{sub 2} transfer rate. However, the limitation was disappeared by supplying mixture gas containing above 2%(v/v) CO{sub 2} and the dissolved CO{sub 2} concentration was maintained at the saturated value. In the range of CO{sub 2} partial pressure in the flue gases from thermal power sations and steel-making plants, the microalgal CO{sub 2} fixation rate was inhibited. The CO{sub 2} fixation rate was successfully formulated by a new empirical equation as a function of dissolved CO{sub 2} concentration, which could be useful for modeling and simulating the performance of photobioreaction with enriched CO{sub 2}. Also, it was found that the CO{sub 2} inhibition of microalgal CO{sub 2} fixation was reversible and that microalgal CO{sub 2} fixation process could be stable against a shock of unusually high CO{sub 2} concentration. 29 refs., 8 figs.

  12. Third-generation biofuels: current and future research on microalgal lipid biotechnology

    Directory of Open Access Journals (Sweden)

    Li-Beisson Yonghua

    2013-11-01

    Full Text Available One pressing issue faced by modern societies is to develop renewable energy for transportation. Microalgal biomass offers an attractive solution due to its high (annual surface biomass productivity, efficient conversion of solar energy into chemical energy and the ability to grow on non-agricultural land. Despite these considerable advantages, microalgal biofuels are not yet commercially sustainable. Major challenges lie in improving both cultivation technologies and microalgal strains. A microalgal crop species is yet to emerge. In this review, we focus on researches aiming at understanding and harnessing lipid metabolism in microalgae in view of producing lipid-based biofuels such as biodiesel. Current biotechnological challenges and key progresses made in the development of algal models, genetic tools and lipid metabolic engineering strategies are reviewed. Possible future research directions to increase oil yields in microalgae are also highlighted.

  13. Energy aspects of microalgal biodiesel production

    Directory of Open Access Journals (Sweden)

    Edith Martinez-Guerra

    2016-03-01

    Full Text Available Algal biodiesel production will play a significant role in sustaining future transportation fuel supplies. A large number of researchers around the world are investigating into making this process sustainable by increasing the energy gains and by optimizing resource-utilization efficiencies. Although, research is being pursued aggressively in all aspects of algal biodiesel production from microalgal cell cultivation, cell harvesting, and extraction and transesterification steps to the final product separation and purification, there is a large disparity in the data presented in recent reports making it difficult to assess the real potential of microalgae as a future energy source. This article discusses some of the key issues in energy consumption in the process of algal biodiesel production and identifies the areas for improvement to make this process energy-positive and sustainable.

  14. Weed infestation of onion in soil reduced cultivation system

    Directory of Open Access Journals (Sweden)

    Marzena Błażej-Woźniak

    2013-12-01

    Full Text Available Field experiment was conducted in the years 1998-2000 in GD Felin. The influence of no-tillage cultivation and conventional tillage with spring ploughing on weed infestation of onion was compared. In experiment four cover crop mulches (Sinapis alba L., Vicia sativa L., Phacelia tanacetifolia B., Avena sativa L. were applied. From annual weeds in weed infestation of onion in great number Matricaria chamomilla L., and Senecio vulgaris L. stepped out. and from perennial - Agropyron repens (L.P.B. Reduced soil cultivation system (no-tillage caused the significant growth of primary weed infestation of onion in comparison with conventional tillage. In all years of investigations the executed pre-sowing ploughing limited significantly the annual weeds' number in primary weed infestation. The applied mulches from cover plants limited in considerable degree the number of primary weed infestation. In all years of investigations the most weeds stepped out on control object. Among investigated cover crop mulches Vicia sativa L. and Avena sativa L. had a profitable effect on decrease of onion`s primary weed infestation. Soil cultivation system and cover crop mulches had no signi ficant residual influence on the secondary weed infestation of onion.

  15. Hydroponic cultivation of soybean for Bioregenerative Life Support Systems (BLSSs)

    Science.gov (United States)

    De Pascale, Stefania; De Micco, Veronica; Aronne, Giovanna; Paradiso, Roberta

    For long time our research group has been involved in experiments aiming to evaluate the possibility to cultivate plants in Space to regenerate resources and produce food. Apart from investigating the response of specific growth processes (at morpho-functional levels) to space factors (namely microgravity and ionising radiation), wide attention has been dedicated to agro-technologies applied to ecologically closed systems. Based on technical and human dietary requirements, soybean [Glycine max (L.) Merr.] is studied as one of the candidate species for hydroponic (soilless) cultivation in the research program MELiSSA (Micro-Ecological Life Support System Alternative) of the European Space Agency (ESA). Soybean seeds show high nutritional value, due to the relevant content of protein, lipids, dietary fiber and biologically active substances such as isoflavones. They can produce fresh sprouts or be transformed in several edible products (soymilk and okara or soy pulp). Soybean is traditionally grown in open field where specific interactions with soil microrganisms occur. Most available information on plant growth, seed productivity and nutrient composition relate to cultivated varieties (cultivars) selected for soil cultivation. However, in a space outpost, plant cultivation would rely on soilless systems. Given that plant growth, seed yield and quality strictly depend on the environmental conditions, to make successful the cultivation of soybean in space, it was necessary to screen all agronomic information according to space constraints. Indeed, selected cultivars have to comply with the space growth environment while providing a suitable nutritional quality to fulfill the astronauts needs. We proposed an objective criterion for the preliminary theoretical selection of the most suitable cultivars for seed production, which were subsequently evaluated in bench tests in hydroponics. Several Space-oriented experiments were carried out in a closed growth chamber to

  16. Microalgal production--a close look at the economics.

    Science.gov (United States)

    Norsker, Niels-Henrik; Barbosa, Maria J; Vermuë, Marian H; Wijffels, René H

    2011-01-01

    Worldwide, microalgal biofuel production is being investigated. It is strongly debated which type of production technology is the most adequate. Microalgal biomass production costs were calculated for 3 different micro algal production systems operating at commercial scale today: open ponds, horizontal tubular photobioreactors and flat panel photobioreactors. For the 3 systems, resulting biomass production costs including dewatering, were 4.95, 4.15 and 5.96 € per kg, respectively. The important cost factors are irradiation conditions, mixing, photosynthetic efficiency of systems, medium- and carbon dioxide costs. Optimizing production with respect to these factors, a price of € 0.68 per kg resulted. At this cost level microalgae become a promising feedstock for biodiesel and bulk chemicals. Photobioreactors may become attractive for microalgal biofuel production. Copyright © 2010 Elsevier Inc. All rights reserved.

  17. Microalgal distribution, diversity and photo-physiological ...

    African Journals Online (AJOL)

    Microalgal distribution, diversity and photo-physiological performance across five ... D'Esny (MAPD), the sandy beach of Blue Bay (SBBB) and the estuarine area of Le ... Microalgal density in the water column (micro-phytoplankton) was highest in ... Diatom was the most abundant microalgal group, followed by dinoflagellate ...

  18. Evaluation of various solvent systems for lipid extraction from wet microalgal biomass and its effects on primary metabolites of lipid-extracted biomass.

    Science.gov (United States)

    Ansari, Faiz Ahmad; Gupta, Sanjay Kumar; Shriwastav, Amritanshu; Guldhe, Abhishek; Rawat, Ismail; Bux, Faizal

    2017-06-01

    Microalgae have tremendous potential to grow rapidly, synthesize, and accumulate lipids, proteins, and carbohydrates. The effects of solvent extraction of lipids on other metabolites such as proteins and carbohydrates in lipid-extracted algal (LEA) biomass are crucial aspects of algal biorefinery approach. An effective and economically feasible algae-based oil industry will depend on the selection of suitable solvent/s for lipid extraction, which has minimal effect on metabolites in lipid-extracted algae. In current study, six solvent systems were employed to extract lipids from dry and wet biomass of Scenedesmus obliquus. To explore the biorefinery concept, dichloromethane/methanol (2:1 v/v) was a suitable solvent for dry biomass; it gave 18.75% lipids (dry cell weight) in whole algal biomass, 32.79% proteins, and 24.73% carbohydrates in LEA biomass. In the case of wet biomass, in order to exploit all three metabolites, isopropanol/hexane (2:1 v/v) is an appropriate solvent system which gave 7.8% lipids (dry cell weight) in whole algal biomass, 20.97% proteins, and 22.87% carbohydrates in LEA biomass. Graphical abstract: Lipid extraction from wet microalgal biomass and biorefianry approach.

  19. Plant growth and gas balance in a plant and mushroom cultivation system

    Science.gov (United States)

    Kitaya, Y.; Tani, A.; Kiyota, M.; Aiga, I.

    1994-11-01

    In order to obtain basic data for construction of a plant cultivation system incorporating a mushroom cultivation subsystem in the CELSS, plant growth and atmospheric CO2 balance in the system were investigated. The plant growth was promoted by a high level of CO2 which resulted from the respiration of the mushroom mycelium in the system. The atmospheric CO2 concentration inside the system changed significantly due to the slight change in the net photosynthetic rate of plants and/or the respiration rate of the mushroom when the plant cultivation system combined directly with the mushroom cultivation subsystem.

  20. Hydroponic cultivation techniques: good results with Eg system

    Energy Technology Data Exchange (ETDEWEB)

    Mimiola, G; Sigliuzzo, C [Tecnagro, Valenzano (Italy)

    1988-12-01

    This report describes results obtained at the Tecnagro agronomic institute (Valenzano, Italy) in which research is being carried out on the use of the Eg hydroponic system developed in Israel. The research program examined the following: composition of nutritive solutions for ornamental plants and vegetables, methods of application of nutritive substances, breeding densities for ornamental plants and vegetables. Successful nutritive formulas were obtained which resulted, in the case of ornamental plants, in increases in plant height (from 30 to 50%), foliage area (50%), as well as, in shortened growth cycles. For vegetables, shortened growth cycles were developed along with a greater and more consistant production. From the economics point of view, tomatoes proved to be the best choice of vegetable for cultivation with the Eg technique.

  1. Kinetics of Chlorella protothecoides microalgal oil using base catalyst

    Directory of Open Access Journals (Sweden)

    Mukesh Kumar

    2016-09-01

    Full Text Available Due to continuous diminishing of fossil fuel resources and emission of greenhouse gases, the search for alternative fuels such as biodiesel and bioethanol has become inevitable. Biodiesel, also known as fatty acid methyl or ethyl ester, has emerged as a substitute for diesel because of similar fuel properties. Presently, biodiesel is produced from edible, non-edible and microalgal oil. Chlorella protothecoides (lipid content 14.6–57.8% is being investigated as the potential microalgae species owing to high oil content, less land area required for cultivation and faster growth rate. The present investigation shows the results of the kinetics of transesterification of C. protothecoides microalgal oil carried out at optimum conditions of catalyst concentration, reaction temperature, molar ratio and reaction time. The percentage of methyl ester yield is the only parameter chosen to carry out the optimum parameter and the kinetics of transesterification. The reaction rate constant was to be 0.0618 min−1. Furthermore, microalgal biodiesel is characterized for physico-chemical properties that are found to meet American (ASTM D6751 and Indian (IS 15607 standards, especially in cold flow properties and stability of conventional biodiesel.

  2. Physiology limits commercially viable photoautotrophic production of microalgal biofuels.

    Science.gov (United States)

    Kenny, Philip; Flynn, Kevin J

    2017-01-01

    Algal biofuels have been offered as an alternative to fossil fuels, based on claims that microalgae can provide a highly productive source of compounds as feedstocks for sustainable transport fuels. Life cycle analyses identify algal productivity as a critical factor affecting commercial and environmental viability. Here, we use mechanistic modelling of the biological processes driving microalgal growth to explore optimal production scenarios in an industrial setting, enabling us to quantify limits to algal biofuels potential. We demonstrate how physiological and operational trade-offs combine to restrict the potential for solar-powered algal-biodiesel production in open ponds to a ceiling of ca. 8000 L ha -1 year -1 . For industrial-scale operations, practical considerations limit production to ca. 6000 L ha -1 year -1 . According to published economic models and life cycle analyses, such production rates cannot support long-term viable commercialisation of solar-powered cultivation of natural microalgae strains exclusively as feedstock for biofuels. The commercial viability of microalgal biofuels depends critically upon limitations in microalgal physiology (primarily in rates of C-fixation); we discuss the scope for addressing this bottleneck concluding that even deployment of genetically modified microalgae with radically enhanced characteristics would leave a very significant logistical if not financial burden.

  3. Characterization of the bacterial metagenome in an industrial algae bioenergy production system

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Shi [Chinese Academy of Sciences; Fulbright, Scott P [Colorado State University; Zeng, Xiaowei [Chinese Academy of Sciences; Yates, Tracy [Solix Biofuels; Wardle, Greg [Solix Biofuels; Chisholm, Stephen T [Colorado State University; Xu, Jian [Chinese Academy of Sciences; Lammers, Peter [New Mexico State University

    2011-03-16

    Cultivation of oleaginous microalgae for fuel generally requires growth of the intended species to the maximum extent supported by available light. The presence of undesired competitors, pathogens and grazers in cultivation systems will create competition for nitrate, phosphate, sulfate, iron and other micronutrients in the growth medium and potentially decrease microalgal triglyceride production by limiting microalgal health or cell density. Pathogenic bacteria may also directly impact the metabolism or survival of individual microalgal cells. Conversely, symbiotic bacteria that enhance microalgal growth may also be present in the system. Finally, the use of agricultural and municipal wastes as nutrient inputs for microalgal production systems may lead to the introduction and proliferation of human pathogens or interfere with the growth of bacteria with beneficial effects on system performance. These considerations underscore the need to understand bacterial community dynamics in microalgal production systems in order to assess microbiome effects on microalgal productivity and pathogen risks. Here we focus on the bacterial component of microalgal production systems and describe a pipeline for metagenomic characterization of bacterial diversity in industrial cultures of an oleaginous alga, Nannochloropsis salina. Environmental DNA was isolated from 12 marine algal cultures grown at Solix Biofuels, a region of the 16S rRNA gene was amplified by PCR, and 16S amplicons were sequenced using a 454 automated pyrosequencer. The approximately 70,000 sequences that passed quality control clustered into 53,950 unique sequences. The majority of sequences belonged to thirteen phyla. At the genus level, sequences from all samples represented 169 different genera. About 52.94% of all sequences could not be identified at the genus level and were classified at the next highest possible resolution level. Of all sequences, 79.92% corresponded to 169 genera and 70 other taxa. We

  4. Microalgal cell disruption via ultrasonic nozzle spraying.

    Science.gov (United States)

    Wang, M; Yuan, W

    2015-01-01

    The objective of this study was to understand the effect of operating parameters, including ultrasound amplitude, spraying pressure, nozzle orifice diameter, and initial cell concentration on microalgal cell disruption and lipid extraction in an ultrasonic nozzle spraying system (UNSS). Two algal species including Scenedesmus dimorphus and Nannochloropsis oculata were evaluated. Experimental results demonstrated that the UNSS was effective in the disruption of microalgal cells indicated by significant changes in cell concentration and Nile red-stained lipid fluorescence density between all treatments and the control. It was found that increasing ultrasound amplitude generally enhanced cell disruption and lipid recovery although excessive input energy was not necessary for best results. The effect of spraying pressure and nozzle orifice diameter on cell disruption and lipid recovery was believed to be dependent on the competition between ultrasound-induced cavitation and spraying-generated shear forces. Optimal cell disruption was not always achieved at the highest spraying pressure or biggest nozzle orifice diameter; instead, they appeared at moderate levels depending on the algal strain and specific settings. Increasing initial algal cell concentration significantly reduced cell disruption efficiency. In all UNSS treatments, the effectiveness of cell disruption and lipid recovery was found to be dependent on the algal species treated.

  5. Minimising losses to predation during microalgae cultivation.

    Science.gov (United States)

    Flynn, Kevin J; Kenny, Philip; Mitra, Aditee

    2017-01-01

    We explore approaches to minimise impacts of zooplanktonic pests upon commercial microalgal crops using system dynamics models to describe algal growth controlled by light and nutrient availability and zooplankton growth controlled by crop abundance and nutritional quality. Losses of microalgal crops are minimised when their growth is fastest and, in contrast, also when growing slowly under conditions of nutrient exhaustion. In many culture systems, however, dwindling light availability due to self-shading in dense suspensions favours slow growth under nutrient sufficiency. Such a situation improves microalgal quality as prey, enhancing zooplankton growth, and leads to rapid crop collapse. Timing of pest entry is important; crop losses are least likely in established, nutrient-exhausted microalgal communities grown for high C-content (e.g. for biofuels). A potentially useful approach is to promote a low level of P-stress that does not adversely affect microalgal growth but which produces a crop that is suboptimal for zooplankton growth.

  6. Cultivation of shear stress sensitive microorganisms in disposable bag reactor systems.

    Science.gov (United States)

    Jonczyk, Patrick; Takenberg, Meike; Hartwig, Steffen; Beutel, Sascha; Berger, Ralf G; Scheper, Thomas

    2013-09-20

    Technical scale (≥5l) cultivations of shear stress sensitive microorganisms are often difficult to perform, as common bioreactors are usually designed to maximize the oxygen input into the culture medium. This is achieved by mechanical stirrers, causing high shear stress. Examples for shear stress sensitive microorganisms, for which no specific cultivation systems exist, are many anaerobic bacteria and fungi, such as basidiomycetes. In this work a disposable bag bioreactor developed for cultivation of mammalian cells was investigated to evaluate its potential to cultivate shear stress sensitive anaerobic Eubacterium ramulus and shear stress sensitive basidiomycetes Flammulina velutipes and Pleurotus sapidus. All cultivations were compared with conventional stainless steel stirred tank reactors (STR) cultivations. Good growth of all investigated microorganisms cultivated in the bag reactor was found. E. ramulus showed growth rates of μ=0.56 h⁻¹ (bag) and μ=0.53 h⁻¹ (STR). Differences concerning morphology, enzymatic activities and growth in fungal cultivations were observed. In the bag reactor growth in form of small, independent pellets was observed while STR cultivations showed intense aggregation. F. velutipes reached higher biomass concentrations (21.2 g l⁻¹ DCW vs. 16.8 g l⁻¹ DCW) and up to 2-fold higher peptidolytic activities in comparison to cell cultivation in stirred tank reactors. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. An economic evaluation comparison of solar water pumping system with engine pumping system for rice cultivation

    Science.gov (United States)

    Treephak, Kasem; Thongpron, Jutturit; Somsak, Dhirasak; Saelao, Jeerawan; Patcharaprakiti, Nopporn

    2015-08-01

    In this paper we propose the design and economic evaluation of the water pumping systems for rice cultivation using solar energy, gasoline fuel and compare both systems. The design of the water and gasoline engine pumping system were evaluated. The gasoline fuel cost used in rice cultivation in an area of 1.6 acres. Under same conditions of water pumping system is replaced by the photovoltaic system which is composed of a solar panel, a converter and an electric motor pump which is compose of a direct current (DC) motor or an alternating current (AC) motor with an inverter. In addition, the battery is installed to increase the efficiency and productivity of rice cultivation. In order to verify, the simulation and economic evaluation of the storage energy battery system with batteries and without batteries are carried out. Finally the cost of four solar pumping systems was evaluated and compared with that of the gasoline pump. The results showed that the solar pumping system can be used to replace the gasoline water pumping system and DC solar pump has a payback less than 10 years. The systems that can payback the fastest is the DC solar pumping system without batteries storage system. The system the can payback the slowest is AC solar pumping system with batteries storage system. However, VAC motor pump of 220 V can be more easily maintained than the motor pump of 24 VDC and batteries back up system can supply a more stable power to the pump system.

  8. Towards increased microalgal productivity in photobioreactors

    NARCIS (Netherlands)

    Bosma, R.; Vermuë, M.H.; Tramper, J.; Wijffels, R.H.

    2010-01-01

    Currently there is much interest to cultivate microalgae for the production of bulk products like lipids for biodiesel or as feedstock for industrial chemical processes. To make the production economically feasible, it is essential to develop cultivation systems in which algae convert the light with

  9. Construction of the Classification and Grading Index System of Cultivated Land Based on the Viewpoint of Sustainable Development

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In order to objectively and reasonably evaluate the actual and potential value of cultivated land, both social and ecological values are introduced into the classification and grading index system of cultivated land based on the viewpoint of sustainable development, after considering the natural and economic values of cultivated land. Index system construction of the sustainable utilization of cultivated land should follow the principles of economic viability, social acceptability, and ecological protection. Classification of cultivated land should take into account the soil fertility of cultivated land. Then, grading of cultivated land is carried out from the practical productivity (or potential productivity) of cultivated land. According to the existing classification index system of cultivated land, the soil, natural and environmental factors in plains, mountains and hills are mainly modified in the classification index system of cultivated land. And index systems for the cultivated land classification in plains, mountains and hills are set up. The grading index system of cultivated land is established based on the economic viability (economic value), social acceptability (social value) and protection of cultivated land (ecological value). Quantitative expression of cultivated land grading index is also carried out.

  10. The Influence of Cultivation System on Distribution Profile Of 137cs and Erosion / Deposition Rate

    Directory of Open Access Journals (Sweden)

    Nita Suhartini

    2016-05-01

    Full Text Available 137Cs radiogenic content in the soil can be used to estimate the rate of erosion and deposition in an area occurring since 1950’s, by comparing the content of the 137Cs in observed site with those in a stable reference site. This experiment aimed to investigate the influence of cultivation type on distribution profile of 137Cs and distribution of erosion and deposition rate in cultivated area. A study site was small cultivated area with slope steepness <10o and length 2 km located in Bojong – Ciawi. For this purpose, the top of a slope was chosen for reference site and three plot sites were selected namely Land Use I that using simple cultivation, Land Use II that using simple cultivation with ridge and furrow, and Land Use III using machine cultivation. The results showed that cultivation could make a movement of 137Cs to the deeper layer and ridges and furrows cultivation system could minimized an erosion process. The net erosion and deposition for land Use I, II and III were -25 t/ha/yr , 24 t/ha/yr and -58 t/ha/yr, respectively.

  11. Optimisation of cultivation parameters in photobioreactors for microalgae cultivation using the A-stat technique

    NARCIS (Netherlands)

    Barbosa, M.J.; Hoogakker, J.; Wijffels, R.H.

    2003-01-01

    Light availability inside the reactor is often the bottleneck in microalgal cultivation and for this reason much attention is being given to light limited growth kinetics of microalgae, aiming at the increase of productivity in photobioreactors. Steady-state culture characteristics are commonly used

  12. Microalgal Mass Culture Room Harvest Records

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The microalgal mass culture room, housed at the NOAA Fisheries' Milford CT laboratory, provides research grade microalgae (phytoplankton) to in-house and...

  13. Metabolic engineering of microalgal based biofuel production: prospects and challenges

    Directory of Open Access Journals (Sweden)

    Chiranjib eBanerjee

    2016-03-01

    Full Text Available The current scenario in renewable energy is focused on development of alternate and sustainable energy sources, amongst which microalgae stands as one of the promising feedstock for biofuel production. It is well known that microalgae generate much larger amounts of biofuels in a shorter time than other sources based on plant seeds. However, the greatest challenge in a transition to algae-based biofuel production is the various other complications involved in microalgal cultivation, its harvesting, concentration, drying and lipid extraction. Several green microalgae accumulate lipids, especially triacylglycerols (TAGs, which are main precursors in the production of lipid. The various aspects on metabolic pathway analysis of an oleaginous microalgae i.e. Chlamydomonas reinhardtii have elucidated some novel metabolically important genes and this enhances the lipid production in this microalgae. Adding to it, various other aspects in metabolic engineering using OptFlux and effectual bioprocess design also gives an interactive snapshot of enhancing lipid production which ultimately improvises the oil yield. This article reviews the current status of microalgal based technologies for biofuel production, bioreactor process design, flux analysis and it also provides various strategies to increase lipids accumulation via metabolic engineering.

  14. Integration of Waste Valorization for Sustainable Production of Chemicals and Materials via Algal Cultivation.

    Science.gov (United States)

    Chen, Yong; Sun, Li-Ping; Liu, Zhi-Hui; Martin, Greg; Sun, Zheng

    2017-11-27

    Managing waste is an increasing problem globally. Microalgae have the potential to help remove contaminants from a range of waste streams and convert them into useful biomass. This article presents a critical review of recent technological developments in the production of chemicals and other materials from microalgae grown using different types of waste. A range of novel approaches are examined for efficiently capturing CO 2 in flue gas via photosynthetic microalgal cultivation. Strategies for using microalgae to assimilate nitrogen, organic carbon, phosphorus, and metal ions from wastewater are considered in relation to modes of production. Generally, more economical open cultivation systems such as raceway ponds are better suited for waste conversion than more expensive closed photobioreactor systems, which might have use for higher-value products. The effect of cultivation methods and the properties of the waste streams on the composition the microalgal biomass is discussed relative to its utilization. Possibilities include the production of biodiesel via lipid extraction, biocrude from hydrothermal liquefaction, and bioethanol or biogas from microbial conversion. Microalgal biomass produced from wastes may also find use in higher-value applications including protein feeds or for the production of bioactive compounds such as astaxanthin or omega-3 fatty acids. However, for some waste streams, further consideration of how to manage potential microbial and chemical contaminants is needed for food or health applications. The use of microalgae for waste valorization holds promise. Widespread implementation of the available technologies will likely follow from further improvements to reduce costs, as well as the increasing pressure to effectively manage waste.

  15. Minimising losses to predation during microalgae cultivation

    OpenAIRE

    Flynn, Kevin J.; Kenny, Philip; Mitra, Aditee

    2017-01-01

    We explore approaches to minimise impacts of zooplanktonic pests upon commercial microalgal crops using system dynamics models to describe algal growth controlled by light and nutrient availability and zooplankton growth controlled by crop abundance and nutritional quality. Losses of microalgal crops are minimised when their growth is fastest and, in contrast, also when growing slowly under conditions of nutrient exhaustion. In many culture systems, however, dwindling light availability due t...

  16. Soybean cultivation for Bioregenerative Life Support Systems (BLSSs): The effect of hydroponic system and nitrogen source

    Science.gov (United States)

    Paradiso, Roberta; Buonomo, Roberta; Dixon, Mike A.; Barbieri, Giancarlo; De Pascale, Stefania

    2014-02-01

    Soybean [Glycine max (L.) Merr.] is one of the plant species selected within the European Space Agency (ESA) Micro-Ecological Life Support System Alternative (MELiSSA) project for hydroponic cultivation in Biological Life Support Systems (BLSSs), because of the high nutritional value of seeds. Root symbiosis of soybean with Bradirhizobium japonicum contributes to plant nutrition in soil, providing ammonium through the bacterial fixation of atmospheric nitrogen. The aim of this study was to evaluate the effects of two hydroponic systems, Nutrient Film Technique (NFT) and cultivation on rockwool, and two nitrogen sources in the nutrient solution, nitrate (as Ca(NO3)2 and KNO3) and urea (CO(NH2)2), on root symbiosis, plant growth and seeds production of soybean. Plants of cultivar 'OT8914', inoculated with B. japonicum strain BUS-2, were grown in a growth chamber, under controlled environmental conditions. Cultivation on rockwool positively influenced root nodulation and plant growth and yield, without affecting the proximate composition of seeds, compared to NFT. Urea as the sole source of N drastically reduced the seed production and the harvest index of soybean plants, presumably because of ammonium toxicity, even though it enhanced root nodulation and increased the N content of seeds. In the view of large-scale cultivation for space colony on planetary surfaces, the possibility to use porous media, prepared using in situ resources, should be investigated. Urea can be included in the nutrient formulation for soybean in order to promote bacterial activity, however a proper ammonium/nitrate ratio should be maintained.

  17. Microalgal carbohydrates: an overview of the factors influencing carbohydrates production, and of main bioconversion technologies for production of biofuels

    DEFF Research Database (Denmark)

    Markou, Giorgos; Angelidaki, Irini; Georgakakis, Dimitris

    2012-01-01

    in research is the cultivation of microalgae for lipids production to generate biodiesel. However, there are several other biological or thermochemical conversion technologies, in which microalgal biomass could be used as substrate. However, the high protein content or the low carbohydrate content...... of the majority of the microalgal species might be a constraint for their possible use in these technologies. Moreover, in the majority of biomass conversion technologies, carbohydrates are the main substrate for production of biofuels. Nevertheless, microalgae biomass composition could be manipulated by several......Microalgal biomass seems to be a promising feedstock for biofuel generation. Microalgae have relative high photosynthetic efficiencies, high growth rates, and some species can thrive in brackish water or seawater and wastewater from the food- and agro-industrial sector. Today, the main interest...

  18. Capacity-oriented curriculum system of optoelectronics in the context of large category cultivation

    Science.gov (United States)

    Luo, Yuan; Hu, Zhangfang; Zhang, Yi

    2017-08-01

    In order to cultivate the innovative talents with the comprehensive development to meet the talents demand for development of economic society, Chongqing University of Posts and Telecommunications implements cultivation based on broadening basic education and enrolment in large category of general education. Optoelectronic information science and engineering major belongs to the electronic engineering category. The "2 +2" mode is utilized for personnel training, where students are without major in the first and second year and assigned to a major within the major categories in the end of the second year. In the context of the comprehensive cultivation, for the changes in the demand for professionals in the global competitive environment with the currently rapid development, especially the demand for the professional engineering technology personnel suitable to industry and development of local economic society, the concept of CDIO engineering ability cultivation is used for reference. Thus the curriculum system for the three-node structure optoelectronic information science and engineering major is proposed, which attaches great importance to engineering practice and innovation cultivation under the background of the comprehensive cultivation. The conformity between the curriculum system and the personnel training objectives is guaranteed effectively, and the consistency between the teaching philosophy and the teaching behavior is enhanced. Therefore, the idea of major construction is clear with specific characteristics.

  19. Simultaneous nitrogen, phosphorous, and hardness removal from reverse osmosis concentrate by microalgae cultivation.

    Science.gov (United States)

    Wang, Xiao-Xiong; Wu, Yin-Hu; Zhang, Tian-Yuan; Xu, Xue-Qiao; Dao, Guo-Hua; Hu, Hong-Ying

    2016-05-01

    While reverse osmosis (RO) is a promising technology for wastewater reclamation, RO concentrate (ROC) treatment and disposal are important issues to consider. Conventional chemical and physical treatment methods for ROC present certain limitations, such as relatively low nitrogen and phosphorus removal efficiencies as well as the requirement of an extra process for hardness removal. This study proposes a novel biological approach for simultaneous removal of nitrogen, phosphorus, and calcium (Ca(2+)) and magnesium (Mg(2+)) ions from the ROC of municipal wastewater treatment plants by microalgal cultivation and algal biomass production. Two microalgae strains, Chlorella sp. ZTY4 and Scenedesmus sp. LX1, were used for batch cultivation of 14-16 days. Both strains grew well in ROC with average biomass production of 318.7 mg/L and lipid contents up to 30.6%, and nitrogen and phosphorus could be effectively removed with efficiencies of up to 89.8% and 92.7%, respectively. Approximately 55.9%-83.7% Ca(2+) could be removed from the system using the cultured strains. Mg(2+) removal began when Ca(2+) precipitation ceased, and the removal efficiency of the ion could reach up to 56.0%. The most decisive factor influencing Ca(2+) and Mg(2+) removal was chemical precipitation with increases in pH caused by algal growth. The results of this study provide a new biological approach for removing nitrogen, phosphorous, and hardness from ROC. The results suggest that microalgal cultivation presents new opportunities for applying an algal process to ROC treatment. The proposed approach serves dual purposes of nutrient and hardness reduction and production of lipid rich micro-algal biomass. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Novel Concept for LSS Based on Advanced Microalgal Biotechnologies

    Science.gov (United States)

    Brown, I.; Jones, J. A.; Bayless, D.; Karakis, S.; Karpov, L.; McKay, D. S.

    2006-01-01

    One of the key issues for successful human space exploration is biomedical life support in hostile space and planetary environments that otherwise cannot sustain life. Bioregenerative life support systems (LSS) are one of the options for atmospheric regeneration. To date, no bioregenerative LSS has shown capability for 100% air regeneration. Nor have these LSS been robust enough to simultaneously provide a regenerable complete food source. In contrast to microalgae, traditional plant approaches, e.g. wheat and lettuce, are lacking essential amino acids, vitamins, and micronutrients. Moreover, the rate of photosynthesis by microalgae significantly exceeds that of high plants. Nevertheless, the employment of microalgae in LSS technology was restricted, until recently, due to high water demands. Also the per person requirement of a 40L volume of microalgae in a photobioreactor, to provide daily O2 production, made an algae-based approach less attractive. By employing a vertically stacked membrane bioreactor, coupled with a solar tracker and photon-delivery system, a lightweight air revitalization system for space based applications, with minimal water requirements, can be developed. Our preliminary estimations suggest that a membrane bioreactor, 8m3 in volume, comprised of 80m2 (twenty 2m x 2m membranes, each spaced 10 cm apart), and a total of 70L of water could produce 2.7 kg of dried microalgal biomass that would supply the energy and essential amino acid requirements, as well as producing sufficient O2 for the daily needs of a 15 member crew. Research on the biochemical content of edible blue-green alga Spirulina (Arthrospira) platensis shows a wide spectrum of stable Spirulina mutants with an enhanced content of amino acids, -carotene, and phycobilliprotein c-phycocyanin. Feeding animals suffering from radiation-induced lesions, c-phycocyanin, extracted from strain 27G, led to a correction in the decrement of dehydrogenase activity and energy-rich phosphate

  1. Optimized production planning model for a multi-plant cultivation system under uncertainty

    Science.gov (United States)

    Ke, Shunkui; Guo, Doudou; Niu, Qingliang; Huang, Danfeng

    2015-02-01

    An inexact multi-constraint programming model under uncertainty was developed by incorporating a production plan algorithm into the crop production optimization framework under the multi-plant collaborative cultivation system. In the production plan, orders from the customers are assigned to a suitable plant under the constraints of plant capabilities and uncertainty parameters to maximize profit and achieve customer satisfaction. The developed model and solution method were applied to a case study of a multi-plant collaborative cultivation system to verify its applicability. As determined in the case analysis involving different orders from customers, the period of plant production planning and the interval between orders can significantly affect system benefits. Through the analysis of uncertain parameters, reliable and practical decisions can be generated using the suggested model of a multi-plant collaborative cultivation system.

  2. Waste biorefineries - integrating anaerobic digestion and microalgae cultivation for bioenergy production.

    Science.gov (United States)

    Chen, Yi-di; Ho, Shih-Hsin; Nagarajan, Dillirani; Ren, Nan-Qi; Chang, Jo-Shu

    2018-04-01

    Commercialization of microalgal cultivation has been well realized in recent decades with the use of effective strains that can yield the target products, but it is still challenged by the high costs arising from mass production, harvesting, and further processing. Recently, more interest has been directed towards the utilization of waste resources, such as sludge digestate, to enhance the economic feasibility and sustainability of microalgae production. Anaerobic digestion for waste disposal and phototrophic microalgal cultivation are well-characterized technologies in both fields. However, integration of anaerobic digestion and microalgal cultivation to achieve substantial economic and environmental benefits is extremely limited, and thus deserves more attention and research effort. In particular, combining these two makes possible an ideal 'waste biorefinery' model, as the C/N/P content in the anaerobic digestate can be used to produce microalgal biomass that serves as feedstock for biofuels, while biogas upgrading can simultaneously be performed by phototrophic CO 2 fixation during microalgal growth. This review is thus aimed at elucidating recent advances as well as challenges and future directions with regard to waste biorefineries associated with the integration of anaerobic waste treatment and microalgal cultivation for bioenergy production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Evaluation of indigenous microalgal isolate Chlorella sp. FC2 IITG as a cell factory for biodiesel production and scale up in outdoor conditions.

    Science.gov (United States)

    Muthuraj, Muthusivaramapandian; Kumar, Vikram; Palabhanvi, Basavaraj; Das, Debasish

    2014-03-01

    The present study reports evaluation of an indigenous microalgal isolate Chlorella sp. FC2 IITG as a potential candidate for biodiesel production. Characterization of the strain was performed under photoautotrophic, heterotrophic, and mixotrophic cultivation conditions. Further, an open-pond cultivation of the strain under outdoor conditions was demonstrated to evaluate growth performance and lipid productivity under fluctuating environmental parameters and in the presence of potential contaminants. The key findings were: (1) the difference in cultivation conditions resulted in significant variation in the biomass productivity (73-114 mg l⁻¹ day⁻¹) and total lipid productivity (35.02-50.42 mg l⁻¹ day⁻¹) of the strain; (2) nitrate and phosphate starvation were found to be the triggers for lipid accumulation in the cell mass; (3) open-pond cultivation of the strain under outdoor conditions resulted in biomass productivity of 44 mg l⁻¹ day⁻¹ and total lipid productivity of 10.7 mg l⁻¹ day⁻¹; (4) a maximum detectable bacterial contamination of 7 % of the total number of cells was recorded in an open-pond system; and (5) fatty acid profiling revealed abundance of palmitic acid (C16:0), oleic acid (C18:1) and linoleic acid (C18:2), which are considered to be the key elements for suitable quality biodiesel.

  4. Microalgal carbohydrates. An overview of the factors influencing carbohydrates production, and of main bioconversion technologies for production of biofuels

    Energy Technology Data Exchange (ETDEWEB)

    Markou, Giorgos; Georgakakis, Dimitris [Agricultural Univ. of Athens (Greece). Dept. of Natural Resources Management and Agricultural Engineering; Angelidaki, Irini [Technical Univ. of Denmark, Lyngby (Denmark). Dept. of Environmental Engineering

    2012-11-15

    Microalgal biomass seems to be a promising feedstock for biofuel generation. Microalgae have relative high photosynthetic efficiencies, high growth rates, and some species can thrive in brackish water or seawater and wastewater from the food- and agro-industrial sector. Today, the main interest in research is the cultivation of microalgae for lipids production to generate biodiesel. However, there are several other biological or thermochemical conversion technologies, in which microalgal biomass could be used as substrate. However, the high protein content or the low carbohydrate content of the majority of the microalgal species might be a constraint for their possible use in these technologies. Moreover, in the majority of biomass conversion technologies, carbohydrates are the main substrate for production of biofuels. Nevertheless, microalgae biomass composition could be manipulated by several cultivation techniques, such as nutrient starvation or other stressed environmental conditions, which cause the microalgae to accumulate carbohydrates. This paper attempts to give a general overview of techniques that can be used for increasing the microalgal biomass carbohydrate content. In addition, biomass conversion technologies, related to the conversion of carbohydrates into biofuels are discussed. (orig.)

  5. Assessment of Environmental Stresses for Enhanced Microalgal Biofuel Production – An Overview

    International Nuclear Information System (INIS)

    Cheng, Dan; He, Qingfang

    2014-01-01

    Microalgal biofuels are currently considered to be the most promising alternative to future renewable energy source. Microalgae have great potential to produce various biofuels, including biodiesel, bioethanol, biomethane, and biohydrogen. Cultivation of biofuel-producing microalgae demands favorable environmental conditions, such as suitable light, temperature, nutrients, salinity, and pH. However, these conditions are not always compatible with the conditions beneficial to biofuel production, because biofuel-related compounds (such as lipids and carbohydrates) tend to accumulate under environmental-stress conditions of light, temperature, nutrient, and salt. This paper presents a brief overview of the effects of environmental conditions on production of microalgal biomass and biofuel, with specific emphasis on how to utilize environmental stresses to improve biofuel productivity. The potential avenues of reaping the benefits of enhanced biofuel production by environmental stresses while maintaining high yields of biomass production have been discussed.

  6. Assessment of environmental stresses for enhanced microalgal biofuel production-an overview

    Directory of Open Access Journals (Sweden)

    Dan eCheng

    2014-07-01

    Full Text Available Microalgal biofuels are currently considered to be the most promising alternative to future renewable energy source. Microalgae have great potential to produce various biofuels, including biodiesel, bioethanol, biomethane, and biohydrogen. Cultivation of biofuel-producing microalgae demands favorable environmental conditions, such as suitable light, temperature, nutrients, salinity, and pH. However, these conditions are not always compatible with the conditions beneficial to biofuel production, because biofuel-related compounds (such as lipids and carbohydrates tend to accumulate under environmental-stress conditions of light, temperature, nutrient, and salt. This paper presents a brief overview of the effects of environmental conditions on production of microalgal biomass and biofuel, with specific emphasis on how to utilize environmental stresses to improve biofuel productivity. The potential avenues of reaping the benefits of enhanced biofuel production by environmental stresses while maintaining high yields of biomass production have been discussed.

  7. Assessment of Environmental Stresses for Enhanced Microalgal Biofuel Production – An Overview

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Dan, E-mail: dxcheng@ualr.edu; He, Qingfang, E-mail: dxcheng@ualr.edu [Department of Applied Science, University of Arkansas at Little Rock, Little Rock, AR (United States)

    2014-07-07

    Microalgal biofuels are currently considered to be the most promising alternative to future renewable energy source. Microalgae have great potential to produce various biofuels, including biodiesel, bioethanol, biomethane, and biohydrogen. Cultivation of biofuel-producing microalgae demands favorable environmental conditions, such as suitable light, temperature, nutrients, salinity, and pH. However, these conditions are not always compatible with the conditions beneficial to biofuel production, because biofuel-related compounds (such as lipids and carbohydrates) tend to accumulate under environmental-stress conditions of light, temperature, nutrient, and salt. This paper presents a brief overview of the effects of environmental conditions on production of microalgal biomass and biofuel, with specific emphasis on how to utilize environmental stresses to improve biofuel productivity. The potential avenues of reaping the benefits of enhanced biofuel production by environmental stresses while maintaining high yields of biomass production have been discussed.

  8. Information system for selection of conditions and equipment for the cultivation of mammalian cells

    Directory of Open Access Journals (Sweden)

    D. R. Batyrgazieva

    2017-01-01

    Full Text Available The use of mammals cells and their products wide application, so the actual problem is a creation of an information system in the field of their cultivation for the organizing and structuring of information on process experimental data. This work is devoted the analysis of mammalian cell cultivation. The main technologies of cell cultivation, necessary equipment and matrices are considered. The main stages of database design and information system is described. The justification of software products are provided and the results of the database and information system implementation are done. The detailed description of all modules of the system, as well as a comparative analysis of the results of the search are in the system to verify correct operation of the system. The scientific and practical significance of the work lies in the fact that the effective tool for presenting knowledge and data for search by specific parameters is required. The convenience of the system is that it is not necessary to address in various data sources to get and conditions of cultivation of mammalian cells, it has already been collected and structured according to parameters. With help of the system, it is possible to select conditions for the cultivation of mammalian cells at the stage of scientific researches that will significantly reduce the time and cost of work, also to rank of recommended technological and hardware solutions. The system has a functional completeness, i.e. in a specific subject area, it ensures the fulfillment of user's requirements, and allows to accumulate and process information.

  9. Water use and its recycling in microalgae cultivation for biofuel application.

    Science.gov (United States)

    Farooq, Wasif; Suh, William I; Park, Min S; Yang, Ji-Won

    2015-05-01

    Microalgal biofuels are not yet economically viable due to high material and energy costs associated with production process. Microalgae cultivation is a water-intensive process compared to other downstream processes for biodiesel production. Various studies found that the production of 1 L of microalgal biodiesel requires approximately 3000 L of water. Water recycling in microalgae cultivation is desirable not only to reduce the water demand, but it also improves the economic feasibility of algal biofuels as due to nutrients and energy savings. This review highlights recently published studies on microalgae water demand and water recycling in microalgae cultivation. Strategies to reduce water footprint for microalgal cultivation, advantages and disadvantages of water recycling, and approaches to mitigate the negative effects of water reuse within the context of water and energy saving are also discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Design of a monitoring system for the cultivation of garden tomato in greenhouse

    Directory of Open Access Journals (Sweden)

    Diana Elizabeth Minda Gilces

    2017-09-01

    Full Text Available This paper briefly discusses the design and implementation of a prototype that monitors temperature, humidity and ultraviolet solar radiation levels in a greenhouse set for the cultivation of garden tomato. The Scrum agile methodology was applied through the deployment of the prototype. The monitoring system is composed by low cost, commercially available sensors, a database and a computer program developed in JAVA. It provides charts, audible and visual alerts, as well as daily, monthly and yearly statistical reports of sensed data. Implementation in the greenhouse aids farmers in the decision- making process regarding crop exposure to the sun, water and ambient temperature, thus enhancing quality of the cultivation process.

  11. An autonomous robot for de-leafing cucumber plants in a high-wire cultivation system

    NARCIS (Netherlands)

    Henten, van E.J.; Tuijl, van B.A.J.; Hoogakker, G.J.; Weerd, van der M.J.; Hemming, J.; Kornet, J.G.; Bontsema, J.

    2005-01-01

    The paper presents an autonomous robot for removing the leaves from cucumber plants grown in a high-wire cultivation system. Leaves at the lower end of the plants are removed because of their reduced vitality, their negligible contribution to canopy photosynthesis and their increased sensitivity for

  12. Microbiota of radish plants, cultivated in closed and open ecological systems

    Science.gov (United States)

    Tirranen, L. S.

    It is common knowledge that microorganisms respond to environmental changes faster than other representatives of the living world. The major aim of this work was to examine and analyze the characteristics of the microbiota of radish culture, cultivated in the closed ecological system of human life-support Bios-3 and in an open system in different experiments. Microbial community of near-root, root zone and phyllosphere of radish were studied at the phases of seedlings, root formation, technical ripeness—by washing-off method—like microbiota of the substrate (expanded clay aggregate) and of the seeds of radish culture. Inoculation on appropriate media was made to count total quantity of anaerobic and aerobic bacteria, bacteria of coliform group, spore-forming, Proteus group, fluorescent, phytopathogenic bacteria, growing on Fermi medium, yeasts, microscopic fungi, Actinomyces. It was revealed that formation of the microbiota of radish plants depends on the age, plant cultivation technology and the specific conditions of the closed system. Composition of microbial conveyor-cultivated in phytotrons varied in quality and in quantity with plant growth phases—in the same manner as cultivation of even-aged soil and hydroponics monocultures which was determined by different qualitative and quantitative composition of root emissions in the course of plant vegetation. The higher plant component formed its own microbial complex different from that formed prior to closure. The microbial complex of vegetable polyculture is more diverse and stable than the monoculture of radish. We registered the changes in the species composition and microorganism quantity during plant cultivation in the closed system on a long-used solution. It was demonstrated that during the short-term (7 days) use of the nutrient solution in the experiments without system closing, the species composition of the microbiota of radish plants was more diverse in a multiple-aged vegetable polyculture (61

  13. Co-cultivation of microalgae in aquaponic systems.

    Science.gov (United States)

    Addy, Min M; Kabir, Faryal; Zhang, Renchuan; Lu, Qian; Deng, Xiangyuan; Current, Dean; Griffith, Richard; Ma, Yiwei; Zhou, Wenguang; Chen, Paul; Ruan, Roger

    2017-12-01

    Aquaponics is a sustainable system for the future farming. In aquaponic systems, the nutrient-rich wastewater generated by the fish provides nutrients needed for vegetable growth. In the present study, the role of microalgae of Chlorella sp. in the floating-raft aquaponic system was evaluated for ammonia control. The yields of algal biomass, vegetable, and removal of the key nutrients from the systems were monitored during the operation of the aquaponic systems. When the systems were in full operation, the algae production was about 4.15±0.19g/m 2 ·day (dry basis) which is considered low because the growth conditions are primarily tailored to fish and vegetable production. However, it was found that algae had a positive effect on balancing pH drop caused by nitrifying bacteria, and the ammonia could be controlled by algae since algae prefer for ammonia nitrogen over nitrate nitrogen. The algae are more efficient for overall nitrogen removal than vegetables. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Phytohormone supplementation significantly increases growth of Chlamydomonas reinhardtii cultivated for biodiesel production.

    Science.gov (United States)

    Park, Won-Kun; Yoo, Gursong; Moon, Myounghoon; Kim, Chul Woong; Choi, Yoon-E; Yang, Ji-Won

    2013-11-01

    Cultivation is the most expensive step in the production of biodiesel from microalgae, and substantial research has been devoted to developing more cost-effective cultivation methods. Plant hormones (phytohormones) are chemical messengers that regulate various aspects of growth and development and are typically active at very low concentrations. In this study, we investigated the effect of different phytohormones on microalgal growth and biodiesel production in Chlamydomonas reinhardtii and their potential to lower the overall cost of commercial biofuel production. The results indicated that all five of the tested phytohormones (indole-3-acetic acid, gibberellic acid, kinetin, 1-triacontanol, and abscisic acid) promoted microalgal growth. In particular, hormone treatment increased biomass production by 54 to 69 % relative to the control growth medium (Tris-acetate-phosphate, TAP). Phytohormone treatments also affected microalgal cell morphology but had no effect on the yields of fatty acid methyl esters (FAMEs) as a percent of biomass. We also tested the effect of these phytohormones on microalgal growth in nitrogen-limited media by supplementation in the early stationary phase. Maximum cell densities after addition of phytohormones were higher than in TAP medium, even when the nitrogen source was reduced to 40 % of that in TAP medium. Taken together, our results indicate that phytohormones significantly increased microalgal growth, particularly in nitrogen-limited media, and have potential for use in the development of efficient microalgal cultivation for biofuel production.

  15. Biomass and Neutral Lipid Production in Geothermal Microalgal Consortia

    Science.gov (United States)

    Bywaters, Kathryn F.; Fritsen, Christian H.

    2015-01-01

    Recently, technologies have been developed that offer the possibility of using algal biomass as feedstocks to energy producing systems – in addition to oil-derived fuels (Bird et al., 2011, 2012). Growing native mixed microalgal consortia for biomass in association with geothermal resources has the potential to mitigate negative impacts of seasonally low temperatures on biomass production systems as well as mitigate some of the challenges associated with growing unialgal strains. We assessed community composition, growth rates, biomass, and neutral lipid production of microalgal consortia obtained from geothermal hot springs in the Great Basin/Nevada area that were cultured under different thermal and light conditions. Biomass production rates ranged from 39.0 to 344.1 mg C L−1 day−1. The neutral lipid production in these consortia with and without shifts to lower temperatures and additions of bicarbonate (both environmental parameters that have been shown to enhance neutral lipid production) ranged from 0 to 38.74 mg free fatty acids (FFA) and triacylglycerols (TAG) L−1 day−1; the upper value was approximately 6% of the biomass produced. The higher lipid values were most likely due to the presence of Achnanthidium sp. Palmitic and stearic acids were the dominant free fatty acids. The S/U ratio (the saturated to unsaturated FA ratio) decreased for cultures shifted from their original temperature to 15°C. Biomass production was within the upper limits of those reported for individual strains, and production of neutral lipids was increased with secondary treatment. All results demonstrate a potential of culturing and manipulating resultant microalgal consortia for biomass-based energy production and perhaps even for biofuels. PMID:25763368

  16. Biomass and Neutral Lipid Production in Geothermal Microalgal Consortia

    Directory of Open Access Journals (Sweden)

    Kathryn Faye Bywaters

    2015-02-01

    Full Text Available Recently, technologies have been developed that offer the possibility of using algal biomass as feedstocks to energy producing systems- in addition to oil-derived fuels (Bird et al., 2011;Bird et al., 2012. Growing native mixed microalgal consortia for biomass in association with geothermal resources has the potential to mitigate negative impacts of seasonally low temperatures on biomass production systems as well as mitigate some of the challenges associated with growing unialgal strains. We assessed community composition, growth rates, biomass and neutral lipid production of microalgal consortia obtained from geothermal hot springs in the Great Basin/Nevada area that were cultured under different thermal and light conditions. Biomass production rates ranged from 368 to 3246 mg C L-1 d-1. The neutral lipid production in these consortia with and without shifts to lower temperatures and additions of bicarbonate (both environmental parameters that have been shown to enhance neutral lipid production ranged from zero to 38.74 mg free fatty acids and triacylglycerols L-1 d-1, the upper value was approximately 6% of the biomass produced. The higher lipid values were most likely due to the presence of Achnanthidium sp. Palmitic and stearic acids were the dominant free fatty acids. The S/U ratio (the saturated to unsaturated FA ratio decreased for cultures shifted from their original temperature to 15°C. Biomass production was within the upper limits of those reported for individual strains, and production of neutral lipids was increased with secondary treatment – all results demonstrate a potential of culturing and manipulating resultant microalgal consortia for biomass-based energy production and perhaps even for biofuels.

  17. Mixotrophic cultivation of oleaginous Chlorella sp. KR-1 mediated by actual coal-fired flue gas for biodiesel production.

    Science.gov (United States)

    Praveenkumar, Ramasamy; Kim, Bohwa; Choi, Eunji; Lee, Kyubock; Cho, Sunja; Hyun, Ju-Soo; Park, Ji-Yeon; Lee, Young-Chul; Lee, Hyun Uk; Lee, Jin-Suk; Oh, You-Kwan

    2014-10-01

    Flue gases mainly consist of CO2 that can be utilized to facilitate microalgal culture for bioenergy production. In the present study, to evaluate the feasibility of the utilization of flue gas from a coal-burning power plant, an indigenous and high-CO2-tolerant oleaginous microalga, Chlorella sp. KR-1, was cultivated under mixotrophic conditions, and the results were evaluated. When the culture was mediated by flue gas, highest biomass (0.8 g cells/L·d) and FAME (fatty acid methyl esters) productivity (121 mg/L·d) were achieved in the mixotrophic mode with 5 g/L glucose, 5 mM nitrate, and a flow rate of 0.2 vvm. By contrast, the photoautotrophic cultivation resulted in a lower biomass (0.45 g cells/L·d) and a lower FAME productivity (60.2 mg/L·d). In general, the fatty acid profiles of Chlorella sp. KR-1 revealed meaningful contents (>40 % of saturated and mono-unsaturated fatty acids) under the mixotrophic condition, which enables the obtainment of a better quality of biodiesel than is possible under the autotrophic condition. Conclusively then, it was established that a microalgal culture mediated by flue gas can be improved by adoption of mixotrophic cultivation systems.

  18. Microalgal toxin(s): characteristics and importance

    African Journals Online (AJOL)

    Prokaryotic and eukaryotic microalgae produce a wide array of compounds with biological activities. These include antibiotics, algicides, toxins, pharmaceutically active compounds and plant growth regulators. Toxic microalgae, in this sense, are common only among the cyanobacteria and dinoflagellates. The microalgal ...

  19. Towards microalgal triglycerides in the commodity markets

    NARCIS (Netherlands)

    Benvenuti, Giulia; Ruiz, Jesús; Lamers, Packo P.; Bosma, Rouke; Wijffels, René H.; Barbosa, Maria J.

    2017-01-01

    Background: Microalgal triglycerides (TAGs) hold great promise as sustainable feedstock for commodity industries. However, to determine research priorities and support business decisions, solid techno-economic studies are essential. Here, we present a techno-economic analysis of two-step TAG

  20. Floristic evolution in an agroforestry system cultivation in Southern Brazil.

    Science.gov (United States)

    Silva, Luís C R; Machado, Sebastião A; Galvão, Franklin; Figueiredo, Afonso

    2016-06-07

    Bracatinga (Mimosa scabrella Bentham) is an important pioneer tree species in Ombrophylous Mixed Forest of Brazil and is widely used as an energy source. In traditional agroforestry systems, regeneration is induced by fire, then pure and dense stands known as bracatinga stands (bracatingais) are formed. In the first year, annual crops are intercalated with the seedlings. At that time the seedlings are thinned, then the stands remain at a fallow period and cut at seven years old. The species is very important mainly for small landowners. We studied the understory species that occur naturally during the succession over several years in order to manage them rationally in the future and maintain the natural vegetation over time. Three to 20 year-old Bracatinga stands were sampled between 1998 and 2011. All tree species with diameter at breast height (DBH) ≥ 5 cm were measured.The floristic evolution was assessed with respect to Sociability Index, the Shannon Diversity Index and the Pielou Evenness Index. Graphs of rank/abundance over different age groups were evaluated using the Kolmogorov-Smirnov test. We identified 153 species dispersed throughout the understory and tend to become aggregated over time.

  1. Encapsulation of Multiple Microalgal Cells via a Combination of Biomimetic Mineralization and LbL Coating

    Directory of Open Access Journals (Sweden)

    Minjeong Kim

    2018-02-01

    Full Text Available The encapsulation of living cells is appealing for its various applications to cell-based sensors, bioreactors, biocatalysts, and bioenergy. In this work, we introduce the encapsulation of multiple microalgal cells in hollow polymer shells of rhombohedral shape by the following sequential processes: embedding of microalgae in CaCO3 crystals; layer-by-layer (LbL coating of polyelectrolytes; and removal of sacrificial crystals. The microcapsule size was controlled by the alteration of CaCO3 crystal size, which is dependent on CaCl2/Na2CO3 concentration. The microalgal cells could be embedded in CaCO3 crystals by a two-step process: heterogeneous nucleation of crystal on the cell surface followed by cell embedment by the subsequent growth of crystal. The surfaces of the microalgal cells were highly favorable for the crystal growth of calcite; thus, micrometer-sized microalgae could be perfectly occluded in the calcite crystal without changing its rhombohedral shape. The surfaces of the microcapsules, moreover, could be decorated with gold nanoparticles, Fe3O4 magnetic nanoparticles, and carbon nanotubes (CNTs, by which we would expect the functionalities of a light-triggered release, magnetic separation, and enhanced mechanical and electrical strength, respectively. This approach, entailing the encapsulation of microalgae in semi-permeable and hollow polymer microcapsules, has the potential for application to microbial-cell immobilization for high-biomass-concentration cultivation as well as various other bioapplications.

  2. Encapsulation of Multiple Microalgal Cells via a Combination of Biomimetic Mineralization and LbL Coating.

    Science.gov (United States)

    Kim, Minjeong; Choi, Myoung Gil; Ra, Ho Won; Park, Seung Bin; Kim, Yong-Joo; Lee, Kyubock

    2018-02-13

    The encapsulation of living cells is appealing for its various applications to cell-based sensors, bioreactors, biocatalysts, and bioenergy. In this work, we introduce the encapsulation of multiple microalgal cells in hollow polymer shells of rhombohedral shape by the following sequential processes: embedding of microalgae in CaCO₃ crystals; layer-by-layer (LbL) coating of polyelectrolytes; and removal of sacrificial crystals. The microcapsule size was controlled by the alteration of CaCO₃ crystal size, which is dependent on CaCl₂/Na₂CO₃ concentration. The microalgal cells could be embedded in CaCO₃ crystals by a two-step process: heterogeneous nucleation of crystal on the cell surface followed by cell embedment by the subsequent growth of crystal. The surfaces of the microalgal cells were highly favorable for the crystal growth of calcite; thus, micrometer-sized microalgae could be perfectly occluded in the calcite crystal without changing its rhombohedral shape. The surfaces of the microcapsules, moreover, could be decorated with gold nanoparticles, Fe₃O₄ magnetic nanoparticles, and carbon nanotubes (CNTs), by which we would expect the functionalities of a light-triggered release, magnetic separation, and enhanced mechanical and electrical strength, respectively. This approach, entailing the encapsulation of microalgae in semi-permeable and hollow polymer microcapsules, has the potential for application to microbial-cell immobilization for high-biomass-concentration cultivation as well as various other bioapplications.

  3. Scenario Analysis of Nutrient Removal from Municipal Wastewater by Microalgal Biofilms

    NARCIS (Netherlands)

    Boelee, N.C.; Temmink, H.; Janssen, M.; Buisman, C.J.N.; Wijffels, R.H.

    2012-01-01

    Microalgae can be used for the treatment of municipal wastewater. The application of microalgal biofilms in wastewater treatment systems seems attractive, being able to remove nitrogen, phosphorus and COD from wastewater at a short hydraulic retention time. This study therefore investigates the area

  4. Soybean cultivar selection for Bioregenerative Life Support Systems (BLSSs) - Hydroponic cultivation

    Science.gov (United States)

    Paradiso, R.; Buonomo, R.; De Micco, V.; Aronne, G.; Palermo, M.; Barbieri, G.; De Pascale, S.

    2012-12-01

    Four soybean cultivars ('Atlantic', 'Cresir', 'Pr91m10' and 'Regir'), selected through a theoretical procedure as suitable for cultivation in BLSS, were evaluated in terms of growth and production. Germination percentage and Mean Germination Time (MGT) were measured. Plants were cultivated in a growth chamber equipped with a recirculating hydroponic system (Nutrient Film Technique). Cultivation was performed under controlled environmental conditions (12 h photoperiod, light intensity 350 μmol m-2 s-1, temperature regime 26/20 °C light/dark, relative humidity 65-75%). Fertigation was performed with a standard Hoagland solution, modified for soybean specific requirements, and EC and pH were kept at 2.0 dS m-1 and 5.5 respectively. The percentage of germination was high (from 86.9% in 'Cresir' to 96.8% in 'Regir')and the MGT was similar for all the cultivars (4.3 days). The growing cycle lasted from 114 in 'Cresir' to 133 days on average in the other cultivars. Differences in plant size were recorded, with 'Pr91m10' plants being the shortest (58 vs 106 cm). Cultivars did not differ significantly in seed yield (12 g plant-1) and in non edible biomass (waste), water consumption and biomass conversion efficiency (water, radiation and acid use indexes). 'Pr91m10' showed the highest protein content in the seeds (35.6% vs 33.3% on average in the other cultivars). Results from the cultivation experiment showed good performances of the four cultivars in hydroponics. The overall analysis suggests that 'Pr91m10' could be the best candidate for the cultivation in a BLSS, coupling the small plant size and the good yield with high resource use efficiency and good seed quality.

  5. Soil carbon and nitrogen mineralization under different tillage systems and Permanent Groundcover cultivation between Orange trees

    Directory of Open Access Journals (Sweden)

    Elcio Liborio Balota

    2011-06-01

    Full Text Available The objective of this work was to evaluate the alterations in carbon and nitrogen mineralization due to different soil tillage systems and groundcover species for intercropped orange trees. The experiment was established in an Ultisol soil (Typic Paleudults originated from Caiuá sandstone in northwestern of the state of Paraná, Brazil, in an area previously cultivated with pasture (Brachiaria humidicola. Two soil tillage systems were evaluated: conventional tillage (CT in the entire area and strip tillage (ST with a 2-m width, each with different groundcover vegetation management systems. The citrus cultivar utilized was the 'Pera' orange (Citrus sinensis grafted onto a 'Rangpur' lime rootstock. The soil samples were collected at a 0-15-cm depth after five years of experiment development. Samples were collected from under the tree canopy and from the inter-row space after the following treatments: (1 CT and annual cover crop with the leguminous Calopogonium mucunoides; (2 CT and perennial cover crop with the leguminous peanut Arachis pintoi; (3 CT and evergreen cover crop with Bahiagrass Paspalum notatum; (4 CT and cover crop with spontaneous B. humidicola grass vegetation; and (5 ST and maintenance of the remaining grass (pasture of B. humidicola. The soil tillage systems and different groundcover vegetation influenced the C and N mineralization, both under the tree canopy and in the inter-row space. The cultivation of B. humidicola under strip tillage provided higher potential mineralization than the other treatments in the inter-row space. Strip tillage increased the C and N mineralization compared to conventional tillage. The grass cultivation increased the C and N mineralization when compared to the others treatments cultivated in the inter-row space.

  6. A Web-Based Decision Support System for Evaluating Soil Suitability for Cassava Cultivation

    Directory of Open Access Journals (Sweden)

    Adewale Opeoluwa Ogunde

    2017-01-01

    Full Text Available Precision agriculture in recent times had assumed a different dimension in order to improve on the poor standard of agriculture. Similarly, the upsurge in technological advancement, most especially in the aspect of machine learning and artificial intelligence, is a promising trend towards a positive solution to this problem. Therefore, this research work presents a decision support system for analyzing and mining knowledge from soil data with respect to its suitability for cassava cultivation. Past data consisting of some major soil attributes were obtained from relevant literature sources. This data was preprocessed using the ARFF Converter, available in WEKA. 70% of the data were used as training data set while remaining 30% were used for testing. Classification rule mining was carried out using J48 decision tree algorithm for the data training. ‘If-then’ construct models were then generated from the decision tree, which was used to develop a system for predicting the suitability status of soil for cassava cultivation. The percentage accuracy of the data classification was 76.5% and 23.5% for correctly classified and incorrectly classified instances respectively. Practically, the developed system was esteemed a prospective tool for farmers, soil laboratories and other users in predicting soil suitability for cassava cultivation.

  7. Role of Pigeonpea Cultivation on Soil Fertility and Farming System Sustainability in Ghana

    Directory of Open Access Journals (Sweden)

    S. Adjei-Nsiah

    2012-01-01

    Full Text Available The productivity of the smallholder farming system in Ghana is under threat due to soil fertility decline. Mineral fertilizer is sparingly being used by smallholder farmers because of prohibitive cost. Grain legumes such as pigeonpea can play a complementary or alternative role as a source of organic fertilizer due to its ability to enhance soil fertility. Despite its importance, the potential of pigeonpea as a soil fertility improvement crop has not been exploited to any appreciable extent and the amount of land cultivated to pigeonpea in Ghana is vey negligible. This paper synthesizes recent studies that have been carried out on pigeonpea in Ghana and discusses the role of pigeonpea cultivation in soil fertility management and its implication for farming system sustainability. The paper shows that recent field studies conducted in both the semi-deciduous forest and the forest/savanna transitional agro-ecological zones of Ghana indicate that pigeonpea/maize rotations can increase maize yield by 75–200%. Barrier to widespread adoption of pigeonpea include land tenure, market, and accessibility to early maturing and high yielding varieties. The paper concludes among other things that in order to promote the cultivation of pigeonpea in Ghana, there is the need to introduce varieties that combine early maturity with high yields and other desirable traits based on farmers preferences.

  8. A trait based dynamic energy budget approach to explore emergent microalgal community structure

    Science.gov (United States)

    Cheng, Y.; Bouskill, N.; Karaoz, U.; Geng, H.; Lane, T.; Pett-Ridge, J.; Mayali, X.; Brodie, E.

    2015-12-01

    Microalgae play important roles in the global carbon budget. Phytoplankton, including microalgae, are responsible for around 50% of global primary production, and also hold promise as a viable renewable biofuel source. Research has been underway for decades to realize the full potential of algal biofuels at the commercial scale, however, uni-algal ponds are typically threatened by collapse due to microalgal grazing and parasite invasions. Recently, it has been proposed that functionally diverse microalgal-bacterial communities can achieve high biomass and/or lipid yields, and are more stable (less susceptible to invasion) than a monoculture. Similar positive diversity-productivity relationships have been observed in a wide range of ecosystem studies, but the purposeful maintenance of a diverse microbiome is less common in managed systems. In our work, a trait based dynamic energy budget model was developed to explore emergent microalgal community structure under various environmental (e.g. light, temperature, nutrient availability) conditions. The complex algal community can be reduced into functional groups (guilds). Each guild (algae or bacteria) is characterized by distinct physiological traits (e.g. nutrient requirement, growth rate, substrate affinity, lipid production) constrained by biochemical trade-offs. These trait values are derived from literature and information encoded in genomic data. Metabolism of the algae and the bacterial species (symbiotic or non-symbiotic) are described within a dynamic energy budget framework. The model offers a mechanistic framework to predict the optimal microalgal community assemblage towards high productivity and resistance to invasion under prevailing environmental conditions.

  9. Development of everlasting flowers (Comanthera elegans (Bong. L.R. Parra & Giul. in three cultivation systems

    Directory of Open Access Journals (Sweden)

    Fernanda da Conceição Moreira

    2017-06-01

    Full Text Available Marketing the inflorescences of Comanthera elegans (Bong. L.R. Parra & Giul. represents a source of income to many families from extractives communities in the portion of the Espinhaço Range located in the state of Minas Gerais, Brazil. Cultivating this species stands out by allying income generation with conservation since the species is currently endangered. This study aimed to assess aspects of the development of C. elegans in three cultivation systems: beds, rows, and whole area. Sowing took place in January 2009 and the inflorescences were harvested in May 2010, which characterized the experimental period. Emergence; plant density; rates of flowering, mortality, resprouting, and recruiting of new individuals; and production of inflorescences per plant and per area were assessed. Emergence began approximately 50 days after sowing. Plant density ranged from 130 to 350 plants.m-2 among the three cultivation systems. The highest mortality rate (18% was observed at the peak of the dry season (August and the overall mortality rate over one reproductive cycle was 49%. Of the plants that lost the aerial part, 36% resprouted. Sprouting and seed germination accounted for 30 and 3% of the recruiting of new individuals, respectively. C. elegans had two bloom (AprilMay 2009 and April-May 2010: 5.4% of the plants bloomed in the first season and 78%, in the second. Each plant produced between three and 178 inflorescences and the highest inflorescence production in terms of weight (232 g.m-2 and number (2,910 inflorescences.m-2 was observed in the cultivation in beds at 1,624 kg.ha-1.

  10. Microalgal bioremediation : Current practices and perspectives

    OpenAIRE

    BISWAJIT RATH

    2011-01-01

    During last two decades, extensive attention has been paid on the management of environmental pollution caused by hazardous materials. A number of methods has been developed for removal of such substances like precipitation, evaporation, ion-exchange etc. However these methods have several disadvantages. This review highlights the alternative biological agent abundantly present in nature i.e Microalgae as a potential sink for removal of such toxic substances from the surrounding. Microalgal b...

  11. Shorter Fallow Cycles Affect the Availability of Noncrop Plant Resources in a Shifting Cultivation System

    Directory of Open Access Journals (Sweden)

    Sarah Paule. Dalle

    2006-12-01

    Full Text Available Shifting cultivation systems, one of the most widely distributed forms of agriculture in the tropics, provide not only crops of cultural significance, but also medicinal, edible, ritual, fuel, and forage resources, which contribute to the livelihoods, health, and cultural identity of local people. In many regions across the globe, shifting cultivation systems are undergoing important changes, one of the most pervasive being a shortening of the fallow cycle. Although there has been much attention drawn to declines in crop yields in conjunction with reductions in fallow times, little if any research has focused on the dynamics of noncrop plant resources. In this paper, we use a data set of 26 fields of the same age, i.e., ~1.5 yr, but differing in the length and frequency of past fallow cycles, to examine the impact of shorter fallow periods on the availability of noncrop plant resources. The resources examined are collected in shifting cultivation fields by the Yucatec Maya in Quintana Roo, Mexico. These included firewood, which is cut from remnant trees and stumps spared at the time of felling, and 17 forage species that form part of the weed vegetation. Firewood showed an overall decrease in basal area with shorter fallow cycles, which was mostly related to the smaller diameter of the spared stumps and trees in short-fallow milpas. In contrast, forage species showed a mixed response. Species increasing in abundance in short-fallow milpas tended to be short-lived herbs and shrubs often with weedy habits, whereas those declining in abundance were predominantly pioneer trees and animal-dispersed species. Coppicing tree species showed a neutral response to fallow intensity. Within the cultural and ecological context of our study area, we expect that declines in firewood availability will be most significant for livelihoods because of the high reliance on firewood for local fuel needs and the fact that the main alternative source of firewood, forest

  12. Dynamic cultivation of human mesenchymal stem cells in a rotating bed bioreactor system based on the Z RP platform.

    Science.gov (United States)

    Diederichs, Solvig; Röker, Stefanie; Marten, Dana; Peterbauer, Anja; Scheper, Thomas; van Griensven, Martijn; Kasper, Cornelia

    2009-01-01

    Because the regeneration of large bone defects is limited by quantitative restrictions and risks of infections, the development of bioartificial bone substitutes is of great importance. To obtain a three-dimensional functional tissue-like graft, static cultivation is inexpedient due to limitations in cell density, nutrition and oxygen support. Dynamic cultivation in a bioreactor system can overcome these restrictions and furthermore provide the possibility to control the environment with regard to pH, oxygen content, and temperature. In this study, a three-dimensional bone construct was engineered by the use of dynamic bioreactor technology. Human adipose tissue derived mesenchymal stem cells were cultivated on a macroporous zirconium dioxide based ceramic disc called Sponceram. Furthermore, hydroxyapatite coated Sponceram was used. The cells were cultivated under dynamic conditions and compared with statically cultivated cells. The differentiation into osteoblasts was initiated by osteogenic supplements. Cellular proliferation during static and dynamic cultivation was compared measuring glucose and lactate concentration. The differentiation process was analysed determining AP-expression and using different specific staining methods. Our results demonstrate much higher proliferation rates during dynamic conditions in the bioreactor system compared to static cultivation measured by glucose consumption and lactate production. Cell densities on the scaffolds indicated higher proliferation on native Sponceram compared to hydroxyapatite coated Sponceram. With this study, we present an excellent method to enhance cellular proliferation and bone lineage specific growth of tissue like structures comprising fibrous (collagen) and globular (mineral) extracellular components. (c) 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009.

  13. Agroforestry systems with fine aroma cocoa cultivation: socio-economic and productive environment

    Directory of Open Access Journals (Sweden)

    Deyanira Mata Anchundia

    2018-01-01

    Full Text Available The agroforestry systems with cocoa are good for many purposes and they give many products to a diversity of soil users, among them, to the families of the producers in their environment. The objective of the research was to evaluate the socioeconomic and productive factors in agroforestry systems with fine aroma cocoa of export, in the El Vergel parish of the Valencia canton, county of Los Ríos, Ecuador. A survey to a random sample of 35 farmers of El Vergel parish was carried out, to evaluate socioeconomic and productivevariables. A descriptive analysis was applied to the data of the surveys. Most of the interviewed producers (71,4 % ignore on agroforestry systems. The farmers possess among 0,63 up to 10 hectares. 100 % of them cultivates the fine aroma cocoa, like main cultivation and other secondary cultivations where they stand out the forest species (48,6 %. The families are conformed by 49,5 % males and 50,5 % women. Most of the farmers (males and women are home bosses, with an age that fluctuates among 45 to 54 years. Alone 37 % of the members of the home is devoted to the work in the agriculture. 51 % of the farmers cohabits in free union and 38,3 % are single. The main monthly entrance oscillates from zero to $488. The monthly expenses of the farmers fluctuate among $101,00 up to $500,00. The analyzed social and productive indicators are not in the level required to achieve the sustainable development of these agroforestry systems.

  14. Heterotrophic cultivation of microalgae for production of biodiesel.

    Science.gov (United States)

    Mohamed, Mohd Shamzi; Wei, Lai Zee; Ariff, Arbakariya B

    2011-08-01

    High cell density cultivation of microalgae via heterotrophic growth mechanism could effectively address the issues of low productivity and operational constraints presently affecting the solar driven biodiesel production. This paper reviews the progress made so far in the development of commercial-scale heterotrophic microalgae cultivation processes. The review also discusses on patentable concepts and innovations disclosed in the past four years with regards to new approaches to microalgal cultivation technique, improvisation on the process flow designs to economically produced biodiesel and genetic manipulation to confer desirable traits leading to much valued high lipid-bearing microalgae strains.

  15. Soil water erosion under different cultivation systems and different fertilization rates and forms over 10 years

    Directory of Open Access Journals (Sweden)

    Ildegardis Bertol

    2014-12-01

    Full Text Available The action of rain and surface runoff together are the active agents of water erosion, and further influences are the soil type, terrain, soil cover, soil management, and conservation practices. Soil water erosion is low in the no-tillage management system, being influenced by the amount and form of lime and fertilizer application to the soil, among other factors. The aim was to evaluate the effect of the form of liming, the quantity and management of fertilizer application on the soil and water losses by erosion under natural rainfall. The study was carried out between 2003 and 2013 on a Humic Dystrupept soil, with the following treatments: T1 - cultivation with liming and corrective fertilizer incorporated into the soil in the first year, and with 100 % annual maintenance fertilization of P and K; T2 - surface liming and corrective fertilization distributed over five years, and with 75 % annual maintenance fertilization of P and K; T3 - surface liming and corrective fertilization distributed over three years, and with 50 % annual maintenance fertilization of P and K; T4 - surface liming and corrective fertilization distributed over two years, and with 25 % annual maintenance fertilization of P and K; T5 - fallow soil, without liming or fertilization. In the rotation the crops black oat (Avena strigosa , soybean (Glycine max , common vetch (Vicia sativa , maize (Zea mays , fodder radish (Raphanus sativus , and black beans (Phaseolus vulgaris . The split application of lime and mineral fertilizer to the soil surface in a no-tillage system over three and five years, results in better control of soil losses than when split in two years. The increase in the amount of fertilizer applied to the soil surface under no-tillage cultivation increases phytomass production and reduces soil loss by water erosion. Water losses in treatments under no-tillage cultivation were low in all crop cycles, with a similar behavior as soil losses.

  16. Cannabis cultivation in Spain: A profile of plantations, growers and production systems.

    Science.gov (United States)

    Alvarez, Arturo; Gamella, Juan F; Parra, Iván

    2016-11-01

    The European market for cannabis derivatives is being transformed. The cultivation of cannabis within the EU and the shift of demand from hashish to domestic marihuana are key aspects of this transformation. Spain, formerly central to the trade of Moroccan hashish, is becoming a marihuana-producing country. The emergence of "import-substitution" has been researched in other EU countries, but thus far the Spanish case remains undocumented. This paper is based on analysis of data of 748 cannabis plantations seized by Spanish police in 2013. The sample comprises reports of seizures identified through a survey of online news and police reports. "Event-analysis" methods were applied to these sources. The analysis offers a typology of plantations, a profile of participants and the different production systems, and a model of regional distribution. Half of the plantations were small (less than 42 plants) and half contained between 100 and 1000 plants, with an average size of 261 plants. About three-quarters of plants were cultivated indoors using stolen electricity. 86% of all plants seized were from large-scale plantations (more than 220 plants). Most plantations were located along the Mediterranean coast, where population and tourism are concentrated. Over three-quarters of those indicted by police were Spanish (85%). Among the foreign owners of big plantations, Dutch nationals predominated. The number of seized plants by province was directly associated with the number of grow shops (β=0.962, pcannabis plantations in the Spanish Mediterranean coast is increasingly replacing import of Moroccan hashish. Indoor cultivation supported by grow shops, that provide the technology and know-how, seem to be the dominant form of organization in this emerging industry. Large-scale plantations may have met most of the demand for marihuana in 2013. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Socio-economic comparison between traditional and improved cultivation methods in agroforestry systems, East Usambara Mountains, Tanzania.

    Science.gov (United States)

    Reyes, Teija; Quiroz, Roberto; Msikula, Shija

    2005-11-01

    The East Usambara Mountains, recognized as one of the 25 most important biodiversity hot spots in the world, have a high degree of species diversity and endemism that is threatened by increasing human pressure on resources. Traditional slash and burn cultivation in the area is no longer sustainable. However, it is possible to maintain land productivity, decrease land degradation, and improve rural people's livelihood by ameliorating cultivation methods. Improved agroforestry seems to be a very convincing and suitable method for buffer zones of conservation areas. Farmers could receive a reasonable net income from their farm with little investment in terms of time, capital, and labor. By increasing the diversity and production of already existing cultivations, the pressure on natural forests can be diminished. The present study shows a significant gap between traditional cultivation methods and improved agroforestry systems in socio-economic terms. Improved agroforestry systems provide approximately double income per capita in comparison to traditional methods. More intensified cash crop cultivation in the highlands of the East Usambara also results in double income compared to that in the lowlands. However, people are sensitive to risks of changing farming practices. Encouraging farmers to apply better land management and practice sustainable cultivation of cash crops in combination with multipurpose trees would be relevant in improving their economic situation in the relatively short term. The markets of most cash crops are already available. Improved agroforestry methods could ameliorate the living conditions of the local population and protect the natural reserves from human disturbance.

  18. Sequential dark-photo fermentation and autotrophic microalgal growth for high-yield and CO{sub 2}-free biohydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Lo, Yung-Chung [Department of Chemical Engineering, National Cheng Kung University, Tainan 701 (China); Chen, Chun-Yen [Department of Chemical Engineering, National Cheng Kung University, Tainan 701 (China); Sustainable Environment Research Center, National Cheng Kung University, Tainan (China); Lee, Chi-Mei [Department of Environmental Engineering, National Chung Hsing University, Taichung (China); Chang, Jo-Shu [Department of Chemical Engineering, National Cheng Kung University, Tainan 701 (China); Sustainable Environment Research Center, National Cheng Kung University, Tainan (China); Center for Biosciences and Biotechnology, National Cheng Kung University, Tainan (China)

    2010-10-15

    Dark fermentation, photo fermentation, and autotrophic microalgae cultivation were integrated to establish a high-yield and CO{sub 2}-free biohydrogen production system by using different feedstock. Among the four carbon sources examined, sucrose was the most effective for the sequential dark (with Clostridium butyricum CGS5) and photo (with Rhodopseudomonas palutris WP3-5) fermentation process. The sequential dark-photo fermentation was stably operated for nearly 80 days, giving a maximum H{sub 2} yield of 11.61 mol H{sub 2}/mol sucrose and a H{sub 2} production rate of 673.93 ml/h/l. The biogas produced from the sequential dark-photo fermentation (containing ca. 40.0% CO{sub 2}) was directly fed into a microalga culture (Chlorella vulgaris C-C) cultivated at 30 C under 60 {mu}mol/m{sup 2}/s illumination. The CO{sub 2} produced from the fermentation processes was completely consumed during the autotrophic growth of C. vulgaris C-C, resulting in a microalgal biomass concentration of 1999 mg/l composed mainly of 48.0% protein, 23.0% carbohydrate and 12.3% lipid. (author)

  19. Cultivation-Independent and Cultivation-Dependent Analysis of Microbes in the Shallow-Sea Hydrothermal System Off Kueishantao Island, Taiwan: Unmasking Heterotrophic Bacterial Diversity and Functional Capacity.

    Science.gov (United States)

    Tang, Kai; Zhang, Yao; Lin, Dan; Han, Yu; Chen, Chen-Tung A; Wang, Deli; Lin, Yu-Shih; Sun, Jia; Zheng, Qiang; Jiao, Nianzhi

    2018-01-01

    Shallow-sea hydrothermal systems experience continuous fluctuations of physicochemical conditions due to seawater influx which generates variable habitats, affecting the phylogenetic composition and metabolic potential of microbial communities. Until recently, studies of submarine hydrothermal communities have focused primarily on chemolithoautotrophic organisms, however, there have been limited studies on heterotrophic bacteria. Here, fluorescence in situ hybridization, high throughput 16S rRNA gene amplicon sequencing, and functional metagenomes were used to assess microbial communities from the shallow-sea hydrothermal system off Kueishantao Island, Taiwan. The results showed that the shallow-sea hydrothermal system harbored not only autotrophic bacteria but abundant heterotrophic bacteria. The potential for marker genes sulfur oxidation and carbon fixation were detected in the metagenome datasets, suggesting a role for sulfur and carbon cycling in the shallow-sea hydrothermal system. Furthermore, the presence of diverse genes that encode transporters, glycoside hydrolases, and peptidase indicates the genetic potential for heterotrophic utilization of organic substrates. A total of 408 cultivable heterotrophic bacteria were isolated, in which the taxonomic families typically associated with oligotrophy, copiotrophy, and phototrophy were frequently found. The cultivation-independent and -dependent analyses performed herein show that Alphaproteobacteria and Gammaproteobacteria represent the dominant heterotrophs in the investigated shallow-sea hydrothermal system. Genomic and physiological characterization of a novel strain P5 obtained in this study, belonging to the genus Rhodovulum within Alphaproteobacteria, provides an example of heterotrophic bacteria with major functional capacity presented in the metagenome datasets. Collectively, in addition to autotrophic bacteria, the shallow-sea hydrothermal system also harbors many heterotrophic bacteria with versatile

  20. Dynamic cell culture system: a new cell cultivation instrument for biological experiments in space

    Science.gov (United States)

    Gmunder, F. K.; Nordau, C. G.; Tschopp, A.; Huber, B.; Cogoli, A.

    1988-01-01

    The prototype of a miniaturized cell cultivation instrument for animal cell culture experiments aboard Spacelab is presented (Dynamic cell culture system: DCCS). The cell chamber is completely filled and has a working volume of 200 microliters. Medium exchange is achieved with a self-powered osmotic pump (flowrate 1 microliter h-1). The reservoir volume of culture medium is 230 microliters. The system is neither mechanically stirred nor equipped with sensors. Hamster kidney (Hak) cells growing on Cytodex 3 microcarriers were used to test the biological performance of the DCCS. Growth characteristics in the DCCS, as judged by maximal cell density, glucose consumption, lactic acid secretion and pH, were similar to those in cell culture tubes.

  1. Convergent Adaptations: Bitter Manioc Cultivation Systems in Fertile Anthropogenic Dark Earths and Floodplain Soils in Central Amazonia

    Science.gov (United States)

    Fraser, James Angus; Alves-Pereira, Alessandro; Junqueira, André Braga; Peroni, Nivaldo; Clement, Charles Roland

    2012-01-01

    Shifting cultivation in the humid tropics is incredibly diverse, yet research tends to focus on one type: long-fallow shifting cultivation. While it is a typical adaptation to the highly-weathered nutrient-poor soils of the Amazonian terra firme, fertile environments in the region offer opportunities for agricultural intensification. We hypothesized that Amazonian people have developed divergent bitter manioc cultivation systems as adaptations to the properties of different soils. We compared bitter manioc cultivation in two nutrient-rich and two nutrient-poor soils, along the middle Madeira River in Central Amazonia. We interviewed 249 farmers in 6 localities, sampled their manioc fields, and carried out genetic analysis of bitter manioc landraces. While cultivation in the two richer soils at different localities was characterized by fast-maturing, low-starch manioc landraces, with shorter cropping periods and shorter fallows, the predominant manioc landraces in these soils were generally not genetically similar. Rather, predominant landraces in each of these two fertile soils have emerged from separate selective trajectories which produced landraces that converged for fast-maturing low-starch traits adapted to intensified swidden systems in fertile soils. This contrasts with the more extensive cultivation systems found in the two poorer soils at different localities, characterized by the prevalence of slow-maturing high-starch landraces, longer cropping periods and longer fallows, typical of previous studies. Farmers plant different assemblages of bitter manioc landraces in different soils and the most popular landraces were shown to exhibit significantly different yields when planted in different soils. Farmers have selected different sets of landraces with different perceived agronomic characteristics, along with different fallow lengths, as adaptations to the specific properties of each agroecological micro-environment. These findings open up new avenues for

  2. Convergent adaptations: bitter manioc cultivation systems in fertile anthropogenic dark earths and floodplain soils in Central Amazonia.

    Directory of Open Access Journals (Sweden)

    James Angus Fraser

    Full Text Available Shifting cultivation in the humid tropics is incredibly diverse, yet research tends to focus on one type: long-fallow shifting cultivation. While it is a typical adaptation to the highly-weathered nutrient-poor soils of the Amazonian terra firme, fertile environments in the region offer opportunities for agricultural intensification. We hypothesized that Amazonian people have developed divergent bitter manioc cultivation systems as adaptations to the properties of different soils. We compared bitter manioc cultivation in two nutrient-rich and two nutrient-poor soils, along the middle Madeira River in Central Amazonia. We interviewed 249 farmers in 6 localities, sampled their manioc fields, and carried out genetic analysis of bitter manioc landraces. While cultivation in the two richer soils at different localities was characterized by fast-maturing, low-starch manioc landraces, with shorter cropping periods and shorter fallows, the predominant manioc landraces in these soils were generally not genetically similar. Rather, predominant landraces in each of these two fertile soils have emerged from separate selective trajectories which produced landraces that converged for fast-maturing low-starch traits adapted to intensified swidden systems in fertile soils. This contrasts with the more extensive cultivation systems found in the two poorer soils at different localities, characterized by the prevalence of slow-maturing high-starch landraces, longer cropping periods and longer fallows, typical of previous studies. Farmers plant different assemblages of bitter manioc landraces in different soils and the most popular landraces were shown to exhibit significantly different yields when planted in different soils. Farmers have selected different sets of landraces with different perceived agronomic characteristics, along with different fallow lengths, as adaptations to the specific properties of each agroecological micro-environment. These findings open

  3. Analysing the Influence of the Spontaneous Aneuploidy Frequency on the Cell Population System Cultivation

    Directory of Open Access Journals (Sweden)

    G. A. Nefedov

    2015-01-01

    Full Text Available The paper provides a qualitative analysis of M.S. Vinogradova's nonlinear model for dynamics of the cell population system. This system describes the stem cells cultivation in vitro under resource constraints. The system consists of two populations, namely: population of normal cells and population of abnormal cells. Resource constraints are considered as linear dependences of mitosis parameters on the normalized densities of each population.One of the key parameters that effects on the realization of the system evolution scenarios is a parameter that determines a share of the normal cells, which pass, when dividing, into population of the abnormal cells. The paper analyses both the existence conditions of the rest points and the changes of the evolution scenarios of population system with changing abovementioned parameter and other system parameters held fixed. It is shown that there is a saddle-node bifurcation in the system; the bifurcation value of the parameter is found. The paper shows the interval of parameter values in which the favorable scenarios of population system evolution are implemented. It also presents results of mathematical modeling.

  4. Direct measurement and characterization of active photosynthesis zones inside biofuel producing and wastewater remediating microalgal biofilms

    Energy Technology Data Exchange (ETDEWEB)

    Bernstein, Hans C.; Kesaano, Maureen; Moll, Karen; Smith, Terence; Gerlach, Robin; Carlson, Ross; Miller, Charles D.; Peyton, Brent; Cooksey, Keith; Gardner, Robert D.; Sims, Ronald C.

    2014-03-01

    Abstract: Microalgal biofilm based technologies are of keen interest due to their high biomass concentrations and ability to utilize renewable resources, such as light and CO2. While photoautotrophic biofilms have long been used for wastewater remediation applications, biofuel production represents a relatively new and under-represented focus area. However, the direct measurement and characterization of fundamental parameters required for physiological analyses are challenging due to biofilm heterogeneity. This study evaluated oxygenic photosynthesis and biofuel precursor molecule production using a novel rotating algal biofilm reactor (RABR) operated at field- and laboratory-scales for wastewater remediation and biofuel production, respectively. Clear differences in oxygenic-photosynthesis, respiration and biofuel-precursor capacities were observed between the two systems and different conditions based on light and nitrogen availability. Nitrogen depletion was not found to have the same effect on lipid accumulation compared to prior planktonic studies. Physiological characterizations of these microalgal biofilms identify potential areas for future process optimization.

  5. A cost analysis of microalgal biomass and biodiesel production in open raceways treating municipal wastewater and under optimum light wavelength.

    Science.gov (United States)

    Kang, Zion; Kim, Byung-Hyuk; Ramanan, Rishiram; Choi, Jong-Eun; Yang, Ji-Won; Oh, Hee-Mock; Kim, Hee-Sik

    2015-01-01

    Open raceway ponds are cost-efficient for mass cultivation of microalgae compared with photobioreactors. Although low-cost options like wastewater as nutrient source is studied to overcome the commercialization threshold for biodiesel production from microalgae, a cost analysis on the use of wastewater and other incremental increases in productivity has not been elucidated. We determined the effect of using wastewater and wavelength filters on microalgal productivity. Experimental results were then fitted into a model, and cost analysis was performed in comparison with control raceways. Three different microalgal strains, Chlorella vulgaris AG10032, Chlorella sp. JK2, and Scenedesmus sp. JK10, were tested for nutrient removal under different light wavelengths (blue, green, red, and white) using filters in batch cultivation. Blue wavelength showed an average of 27% higher nutrient removal and at least 42% higher chemical oxygen demand removal compared with white light. Naturally, the specific growth rate of microalgae cultivated under blue wavelength was on average 10.8% higher than white wavelength. Similarly, lipid productivity was highest in blue wavelength, at least 46.8% higher than white wavelength, whereas FAME composition revealed a mild increase in oleic and palmitic acid levels. Cost analysis reveals that raceways treating wastewater and using monochromatic wavelength would decrease costs from 2.71 to 0.73 $/kg biomass. We prove that increasing both biomass and lipid productivity is possible through cost-effective approaches, thereby accelerating the commercialization of low-value products from microalgae, like biodiesel.

  6. Aboriginal health learning in the forest and cultivated gardens: building a nutritious and sustainable food system.

    Science.gov (United States)

    Stroink, Mirella L; Nelson, Connie H

    2009-01-01

    Sustainable food systems are those in which diverse foods are produced in close proximity to a market. A dynamic, adaptive knowledge base that is grounded in local culture and geography and connected to outside knowledge resources is essential for such food systems to thrive. Sustainable food systems are particularly important to remote and Aboriginal communities, where extensive transportation makes food expensive and of poorer nutritional value. The Learning Garden program was developed and run with two First Nation communities in northwestern Ontario. With this program, the team adopted a holistic and experiential model of learning to begin rebuilding a knowledge base that would support a sustainable local food system. The program involved a series of workshops held in each community and facilitated by a community-based coordinator. Topics included cultivated gardening and forest foods. Results of survey data collected from 20 Aboriginal workshop participants are presented, revealing a moderate to low level of baseline knowledge of the traditional food system, and a reliance on the mainstream food system that is supported by food values that place convenience, ease, and price above the localness or cultural connectedness of the food. Preliminary findings from qualitative data are also presented on the process of learning that occurred in the program and some of the insights we have gained that are relevant to future adaptations of this program.

  7. Cell disruption and lipid extraction for microalgal biorefineries: A review.

    Science.gov (United States)

    Lee, Soo Youn; Cho, Jun Muk; Chang, Yong Keun; Oh, You-Kwan

    2017-11-01

    The microalgae-based biorefinement process has attracted much attention from academic and industrial researchers attracted to its biofuel, food and nutraceutical applications. In this paper, recent developments in cell-disruption and lipid-extraction methods, focusing on four biotechnologically important microalgal species (namely, Chlamydomonas, Haematococcus, Chlorella, and Nannochloropsis spp.), are reviewed. The structural diversity and rigidity of microalgal cell walls complicate the development of efficient downstream processing methods for cell-disruption and subsequent recovery of intracellular lipid and pigment components. Various mechanical, chemical and biological cell-disruption methods are discussed in detail and compared based on microalgal species and status (wet/dried), scale, energy consumption, efficiency, solvent extraction, and synergistic combinations. The challenges and prospects of the downstream processes for the future development of eco-friendly and economical microalgal biorefineries also are outlined herein. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Physico-chemical and biotic factors influencing microalgal seed ...

    African Journals Online (AJOL)

    Physico-chemical and biotic factors influencing microalgal seed culture propagation for inoculation of a ... African Journal of Biotechnology ... used to inoculate an open raceway pond for large scale biomass production for biodiesel production.

  9. First steps towards the successful surface-based cultivation of human embryonic stem cells in hanging drop systems.

    Science.gov (United States)

    Schulz, Julia C; Stumpf, Patrick S; Katsen-Globa, Alisa; Sachinidis, Agapios; Hescheler, Jürgen; Zimmermann, Heiko

    2012-11-01

    Miniaturization and parallelization of cell culture procedures are in focus of research in order to develop test platforms with low material consumption and increased standardization for toxicity and drug screenings. The cultivation in hanging drops (HDs) is a convenient and versatile tool for biological applications and represents an interesting model system for the screening applications due to its uniform shape, the advantageous gas supply, and the small volume. However, its application has so far been limited to non-adherent and aggregate forming cells. Here, we describe for the first time the proof-of-principle regarding the adherent cultivation of human embryonic stem cells in HD. For this microcarriers were added to the droplet as dynamic cultivation surfaces resulting in a maintained pluripotency and proliferation capacity for 10 days. This enables the HD technique to be extended to the cultivation of adherence-dependent stem cells. Also, the possible automation of this method by implementation of liquid handling systems opens new possibilities for miniaturized screenings, the improvement of cultivation and differentiation conditions, and toxicity and drug development.

  10. Qualitative Analysis of Microbial Dynamics during Anaerobic Digestion of Microalgal Biomass in a UASB Reactor

    Directory of Open Access Journals (Sweden)

    Anna Doloman

    2017-01-01

    Full Text Available Anaerobic digestion (AD is a microbiologically coordinated process with dynamic relationships between bacterial players. Current understanding of dynamic changes in the bacterial composition during the AD process is incomplete. The objective of this research was to assess changes in bacterial community composition that coordinates with anaerobic codigestion of microalgal biomass cultivated on municipal wastewater. An upflow anaerobic sludge blanket reactor was used to achieve high rates of microalgae decomposition and biogas production. Samples of the sludge were collected throughout AD and extracted DNA was subjected to next-generation sequencing using methanogen mcrA gene specific and universal bacterial primers. Analysis of the data revealed that samples taken at different stages of AD had varying bacterial composition. A group consisting of Bacteroidales, Pseudomonadales, and Enterobacteriales was identified to be putatively responsible for the hydrolysis of microalgal biomass. The methanogenesis phase was dominated by Methanosarcina mazei. Results of observed changes in the composition of microbial communities during AD can be used as a road map to stimulate key bacterial species identified at each phase of AD to increase yield of biogas and rate of substrate decomposition. This research demonstrates a successful exploitation of methane production from microalgae without any biomass pretreatment.

  11. Qualitative Analysis of Microbial Dynamics during Anaerobic Digestion of Microalgal Biomass in a UASB Reactor

    Science.gov (United States)

    Doloman, Anna; Soboh, Yousef; Walters, Andrew J.; Sims, Ronald C.

    2017-01-01

    Anaerobic digestion (AD) is a microbiologically coordinated process with dynamic relationships between bacterial players. Current understanding of dynamic changes in the bacterial composition during the AD process is incomplete. The objective of this research was to assess changes in bacterial community composition that coordinates with anaerobic codigestion of microalgal biomass cultivated on municipal wastewater. An upflow anaerobic sludge blanket reactor was used to achieve high rates of microalgae decomposition and biogas production. Samples of the sludge were collected throughout AD and extracted DNA was subjected to next-generation sequencing using methanogen mcrA gene specific and universal bacterial primers. Analysis of the data revealed that samples taken at different stages of AD had varying bacterial composition. A group consisting of Bacteroidales, Pseudomonadales, and Enterobacteriales was identified to be putatively responsible for the hydrolysis of microalgal biomass. The methanogenesis phase was dominated by Methanosarcina mazei. Results of observed changes in the composition of microbial communities during AD can be used as a road map to stimulate key bacterial species identified at each phase of AD to increase yield of biogas and rate of substrate decomposition. This research demonstrates a successful exploitation of methane production from microalgae without any biomass pretreatment. PMID:29259629

  12. Microalgal Species Selection for Biodiesel Production Based on Fuel Properties Derived from Fatty Acid Profiles

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    Md. Nurun Nabi

    2013-10-01

    Full Text Available Physical and chemical properties of biodiesel are influenced by structural features of the fatty acids, such as chain length, degree of unsaturation and branching of the carbon chain. This study investigated if microalgal fatty acid profiles are suitable for biodiesel characterization and species selection through Preference Ranking Organisation Method for Enrichment Evaluation (PROMETHEE and Graphical Analysis for Interactive Assistance (GAIA analysis. Fatty acid methyl ester (FAME profiles were used to calculate the likely key chemical and physical properties of the biodiesel [cetane number (CN, iodine value (IV, cold filter plugging point, density, kinematic viscosity, higher heating value] of nine microalgal species (this study and twelve species from the literature, selected for their suitability for cultivation in subtropical climates. An equal-parameter weighted (PROMETHEE-GAIA ranked Nannochloropsis oculata, Extubocellulus sp. and Biddulphia sp. highest; the only species meeting the EN14214 and ASTM D6751-02 biodiesel standards, except for the double bond limit in the EN14214. Chlorella vulgaris outranked N. oculata when the twelve microalgae were included. Culture growth phase (stationary and, to a lesser extent, nutrient provision affected CN and IV values of N. oculata due to lower eicosapentaenoic acid (EPA contents. Application of a polyunsaturated fatty acid (PUFA weighting to saturation led to a lower ranking of species exceeding the double bond EN14214 thresholds. In summary, CN, IV, C18:3 and double bond limits were the strongest drivers in equal biodiesel parameter-weighted PROMETHEE analysis.

  13. Abiotic characteristics and microalgal dynamics in South Africa's largest estuarine lake during a wet to dry transitional phase

    Science.gov (United States)

    Nunes, Monique; Adams, Janine B.; Bate, Guy C.; Bornman, Thomas G.

    2017-11-01

    The summer of 2012/2013 signified the end of the dry phase in the St Lucia estuarine system that lasted for over a decade. The increased rainfall coupled with the partial re-connection of the Mfolozi River to the estuarine system shifted St Lucia to a new limnetic state. With the increased availability of habitat due to the higher water level, it was expected that microalgal biomass and abundance would rapidly increase through recruitment from refuge areas i.e. South Lake and new introductions. Microalgal and physico-chemical data were collected at three sites within the Mfolozi/Msunduzi River and at 23 sites within the St Lucia estuarine system between June 2014 and February 2015. Results from this study indicated low biomass for both phytoplankton (<5 μg l-1) and microphytobenthos (<60 mg m-2) because of local and external drivers. These included limited nutrient and light availability, variable water residence times, biomass dilution and heterogeneity of the sediment. The high spatio-temporal variability limits the effectiveness of using the microalgal communities to detect change in the estuarine lake. In addition, significant intrasystem differences were observed between the three main lake basins and Narrows, due to the influence of the freshwater input from the Mfolozi River. This study provides insight into the spatio-temporal variability of physico-chemical conditions and microalgal communities during the 2014-2015 limnetic state.

  14. Dark Earths and manioc cultivation in Central Amazonia: a window on pre-Columbian agricultural systems?

    Directory of Open Access Journals (Sweden)

    James A. Fraser

    Full Text Available Many commentators highlight the fertility of Anthropogenic Dark Earths (ADE, emphasizing their potential for sustainable agriculture. Some scholars believe that terra mulata (the less fertile, more extensive form of ADE was created by means of agricultural practices used by large settled populations of pre-Columbian farmers. But what was it that these Amerindian farmers were growing? Until recently, scholarly consensus held that manioc does not perform well on ADE. New research on the middle Madeira River is showing, however, that this consensus was premature. In this region, the most common crop in ADE fields is bitter manioc. Farmers there have various landraces of manioc that they believe yield particularly well on ADE, and logically plant more of these varieties on ADE. Aspects of the behaviour and perception of manioc cultivation among 52 farmers at the community of Barro Alto were measured quantitatively on four terra firme soil types (Terra Preta, Terra Mulata, Oxisols and Ultisols. These farmers plant different configurations of landraces in different soils, according to their perception of the suitability of particular landraces and their characteristics to certain soil types and successional processes. This, in turn, shapes selective pressures on these varieties, as new genetic material incorporated from volunteer seedlings is more likely to contain traits present in the most prevalent landrace(s in each soil type. Owing to localized population pressure at Barro Alto, manioc is under more intensive cultivation systems, with shorter cropping periods (5-10 months and shorter fallow periods (1-2 years. The outcome of these processes is different co-evolutionary dynamics on ADE as opposed to non-anthropogenic soils. Further anthropological study of manioc swiddening in one of the richest agricultural environments in Amazonia can fill a gap in the literature, thus opening an additional window on the pre-Columbian period.

  15. Dark Earths and manioc cultivation in Central Amazonia: a window on pre-Columbian agricultural systems?

    Directory of Open Access Journals (Sweden)

    James A. Fraser

    2008-08-01

    Full Text Available Many commentators highlight the fertility of Anthropogenic Dark Earths (ADE, emphasizing their potential for sustainable agriculture. Some scholars believe that terra mulata (the less fertile, more extensive form of ADE was created by means of agricultural practices used by large settled populations of pre-Columbian farmers. But what was it that these Amerindian farmers were growing? Until recently, scholarly consensus held that manioc does not perform well on ADE. New research on the middle Madeira River is showing, however, that this consensus was premature. In this region, the most common crop in ADE fields is bitter manioc. Farmers there have various landraces of manioc that they believe yield particularly well on ADE, and logically plant more of these varieties on ADE. Aspects of the behaviour and perception of manioc cultivation among 52 farmers at the community of Barro Alto were measured quantitatively on four terra firme soil types (Terra Preta, Terra Mulata, Oxisols and Ultisols. These farmers plant different configurations of landraces in different soils, according to their perception of the suitability of particular landraces and their characteristics to certain soil types and successional processes.This, in turn, shapes selective pressures on these varieties, as new genetic material incorporated from volunteer seedlings is more likely to contain traits present in the most prevalent landrace(s in each soil type. Owing to localized population pressure at Barro Alto, manioc is under more intensive cultivation systems, with shorter cropping periods (5-10 months and shorter fallow periods (1-2 years. The outcome of these processes is different co-evolutionary dynamics on ADE as opposed to non-anthropogenic soils. Further anthropological study of manioc swiddening in one of the richest agricultural environments in Amazonia can fill a gap in the literature, thus opening an additional window on the pre-Columbian period.

  16. Growth and metabolic characteristics of oleaginous microalgal isolates from Nilgiri biosphere Reserve of India.

    Science.gov (United States)

    Thangavel, Kalaiselvi; Radha Krishnan, Preethi; Nagaiah, Srimeena; Kuppusamy, Senthil; Chinnasamy, Senthil; Rajadorai, Jude Sudhagar; Nellaiappan Olaganathan, Gopal; Dananjeyan, Balachandar

    2018-01-03

    Renewable energy for sustainable development is a subject of a worldwide debate since continuous utilization of non-renewable energy sources has a drastic impact on the environment and economy; a search for alternative energy resources is indispensable. Microalgae are promising and potential alternate energy resources for biodiesel production. Thus, our efforts were focused on surveying the natural diversity of microalgae for the production of biodiesel. The present study aimed at identification, isolation, and characterization of oleaginous microalgae from shola forests of Nilgiri Biosphere Reserve (NBR), the biodiversity hot spot of India, where the microalgal diversity has not yet been systematically investigated. Overall the higher biomass yield, higher lipid accumulation and thermotolerance observed in the isolated microalgal strains have been found to be the desirable traits for the efficient biodiesel production. Species composition and diversity analysis yielded ten potential microalgal isolates belonging to Chlorophyceae and Cyanophyceae classes. The chlorophytes exhibited higher growth rate, maximum biomass yield, and higher lipid accumulation than Cyanophyceae. Among the chlorophytes, the best performing strains were identified and represented by Acutodesmus dissociatus (TGA1), Chlorella sp. (TGA2), Chlamydomonadales sp. (TGA3) and Hindakia tetrachotoma (PGA1). The Chlamydomonadales sp. recorded with the highest growth rate, lipid accumulation and biomass yield of 0.28 ± 0.03 day -1 (μ exp ), 29.7 ± 0.69% and 134.17 ± 16.87 mg L -1  day -1 , respectively. It was also found to grow well at various temperatures, viz., 25 °C, 35 °C, and 45 °C, indicating its suitability for open pond cultivation. The fatty acid methyl ester (FAME) analysis of stationary phase cultures of selected four algal strains by tandem mass spectrograph showed C16:0, C18:1 and C18:3 as dominant fatty acids suitable for biodiesel production. All the three

  17. Towards microalgal triglycerides in the commodity markets.

    Science.gov (United States)

    Benvenuti, Giulia; Ruiz, Jesús; Lamers, Packo P; Bosma, Rouke; Wijffels, René H; Barbosa, Maria J

    2017-01-01

    Microalgal triglycerides (TAGs) hold great promise as sustainable feedstock for commodity industries. However, to determine research priorities and support business decisions, solid techno-economic studies are essential. Here, we present a techno-economic analysis of two-step TAG production (growth reactors are operated in continuous mode such that multiple batch-operated stress reactors are inoculated and harvested sequentially) for a 100-ha plant in southern Spain using vertically stacked tubular photobioreactors. The base case is established with outdoor pilot-scale data and based on current process technology. For the base case, production costs of 6.7 € per kg of biomass containing 24% TAG (w/w) were found. Several scenarios with reduced production costs were then presented based on the latest biological and technological advances. For instance, much effort should focus on increasing the photosynthetic efficiency during the stress and growth phases, as this is the most influential parameter on production costs (30 and 14% cost reduction from base case). Next, biological and technological solutions should be implemented for a reduction in cooling requirements (10 and 4.5% cost reduction from base case when active cooling is avoided and cooling setpoint is increased, respectively). When implementing all the suggested improvements, production costs can be decreased to 3.3 € per kg of biomass containing 60% TAG (w/w) within the next 8 years. With our techno-economic analysis, we indicated a roadmap for a substantial cost reduction. However, microalgal TAGs are not yet cost efficient when compared to their present market value. Cost-competiveness strictly relies on the valorization of the whole biomass components and on cheaper PBR designs (e.g. plastic film flat panels). In particular, further research should focus on the development and commercialization of PBRs where active cooling is avoided and stable operating temperatures are maintained by the water

  18. Degeneration of penicillin production in ethanol-limited chemostat cultivations of Penicillium chrysogenum : A systems biology approach

    NARCIS (Netherlands)

    Douma, Rutger D.; Batista, Joana M.; Touw, Kai M.; Kiel, Jan A. K. W.; Zhao, Zheng; Veiga, Tania; Klaassen, Paul; Bovenberg, Roel A. L.; Daran, Jean-Marc; van Gulik, Walter M.; Heijnen, J.J.; Krikken, Arjen

    2011-01-01

    Background: In microbial production of non-catabolic products such as antibiotics a loss of production capacity upon long-term cultivation (for example chemostat), a phenomenon called strain degeneration, is often observed. In this study a systems biology approach, monitoring changes from gene to

  19. An Autonomous Robot for De-leafing Cumcumber Plants grown in a High-wire Cultivation System

    NARCIS (Netherlands)

    Henten, van E.J.; Tuijl, van B.A.J.; Hoogakker, G.J.; Weerd, van der M.J.; Hemming, J.; Kornet, J.G.; Bontsema, J.

    2006-01-01

    The paper presents an autonomous robot for removing the leaves from cucumber plants grown in a high-wire cultivation system. Leaves at the lower end of the plants are removed because of their reduced vitality, their negligible contribution to canopy photosynthesis and their increased sensitivity to

  20. Study of Acari and Collembola Populations in Four Cultivation Systems in Dourados - MS

    Directory of Open Access Journals (Sweden)

    Rosilda Mara Mussury

    2002-09-01

    Full Text Available The impact four cultivation systems on the soil fauna was studied, using Oribatida and Gamasida acarids as bioindicators and collembolan. The research was carried out in experimental fields, located in EMBRAPA - CPAO in Dourados, Centerwest of Brazil from July 1997 to December 1999. The constant pasture system presented smaller impact on the soil fauna followed by agricultural cattle rotation and a direct plantation system. In the conventional plantation series, the populational density of the mesofauna organisms was low, especially collembolan families.O impacto de quatro sistemas de cultivo sobre a fauna de solo foram estudados, utilizando-se como bioindicadores os acari Oribatida e Gamasida e os Collembola. A pesquisa foi conduzida em campos experimentais, localizados na EMBRAPA - CPAO no município de Dourados, MS, no período de julho de 1997 à dezembro de 1999. O sistema de pastagem contínua apresentou menor impacto sobre a fauna de solo seguido da rotação agricultura pecuária e do sistema de plantio direto. Nas sucessões do plantio convencional, a densidade populacional dos organismos da mesofauna foi baixa, em especial as famílias de colembolos.

  1. [A hydroponic cultivation system for rapid high-yield transient protein expression in Nicotiana plants under laboratory conditions].

    Science.gov (United States)

    Mo, Qianzhen; Mai, Rongjia; Yang, Zhixiao; Chen, Minfang; Yang, Tiezhao; Lai, Huafang; Yang, Peiliang; Chen, Qiang; Zhou, Xiaohong

    2012-06-01

    To develop a hydroponic Nicotiana cultivation system for rapid and high-yield transient expression of recombinant proteins under laboratory conditions. To establish the hydroponic cultivation system, several parameters were examined to define the optimal conditions for the expression of recombinant proteins in plants. We used the green fluorescent protein (GFP) and the geminiviral plant transient expression vector as the model protein/expression vector. We examined the impact of Nicotiana species, the density and time of Agrobacterium infiltration, and the post-infiltration growth period on the accumulation of GFP. The expression levels of GFP in Nicotiana leaves were then examined by Western blotting and ELISA. Our data indicated that a hydroponic Nicotiana cultivation system with a light intensity of 9000 LX/layer, a light cycle of 16 h day/8 h night, a temperature regime of 28 degrees celsius; day/21 degrees celsius; night, and a relative humidity of 80% could support the optimal plant growth and protein expression. After agroinfiltration with pBYGFPDsRed.R/LBA4404, high levels of GFP expression were observed in both N. benthamiana and N. tobaccum (cv. Yuyan No.5) plants cultured with this hydroponic cultivation system. An optimal GFP expression was achieved in both Nicotiana species leaves 4 days after infiltration by Agrobacterium with an OD(600) of 0.8. At a given time point, the average biomass of N. tobaccum (cv. Yuyan No.5) was significantly higher than that of N. benthamiana. The leaves from 6-week-old N. benthamiana plants and 5-week-old N. tobaccum (cv. Yuyan No.5) plants could be the optimal material for agroinfiltration. We have established a hydroponic cultivation system that allows robust growth of N. benthamiana and N. tobaccum (cv. Yuyan No.5) plants and the optimal GFP expression in the artificial climate box.

  2. Application of the system of water erosion control measures in growths of special cultivations

    Directory of Open Access Journals (Sweden)

    Vítězslav Hálek

    2004-01-01

    Full Text Available The aim of the study is to select an optimal variant of the system of water erosion control measures. The water erosion issue was observed and evaluated in 15 blocks of special cultivations-vineyards and orchards. These blocks are situated in the managed area of the join-stock company PATRIA Kobylí. At first the average long-term loss of soil with the influence of water erosion is calculated. The universal Wischmeier-Smith equation is used for this purpose. If the calculated loss of soil exceeds the permissible value, the erosion control measures have to be suggested. The optimal variant has been selected on the bases of the evaluation of several kinds of measures in each block. This variant follows first of all the erosion control efficiency, but also demands on production as well as slope accessibility for mechanization, expensiveness and some negative sides of suggested measures. The suggested system of water erosion control measures contributes to increasing of soil fertility and production ability with the respect to landscape management and environmental protection.

  3. Non-Invasive Rapid Harvest Time Determination of Oil-Producing Microalgae Cultivations for Biodiesel Production by Using Chlorophyll Fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Qiao, Yaqin [Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan (China); University of Chinese Academy of Sciences, Beijing (China); Rong, Junfeng [SINOPEC Research Institute of Petroleum Processing, Beijing (China); Chen, Hui; He, Chenliu; Wang, Qiang, E-mail: wangqiang@ihb.ac.cn [Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan (China)

    2015-10-05

    For the large-scale cultivation of microalgae for biodiesel production, one of the key problems is the determination of the optimum time for algal harvest when algae cells are saturated with neutral lipids. In this study, a method to determine the optimum harvest time in oil-producing microalgal cultivations by measuring the maximum photochemical efficiency of photosystem II, also called Fv/Fm, was established. When oil-producing Chlorella strains were cultivated and then treated with nitrogen starvation, it not only stimulated neutral lipid accumulation, but also affected the photosynthesis system, with the neutral lipid contents in all four algae strains – Chlorella sorokiniana C1, Chlorella sp. C2, C. sorokiniana C3, and C. sorokiniana C7 – correlating negatively with the Fv/Fm values. Thus, for the given oil-producing algae, in which a significant relationship between the neutral lipid content and Fv/Fm value under nutrient stress can be established, the optimum harvest time can be determined by measuring the value of Fv/Fm. It is hoped that this method can provide an efficient way to determine the harvest time rapidly and expediently in large-scale oil-producing microalgae cultivations for biodiesel production.

  4. Effect of reversal of the flow direction on hydrodynamic characteristics and plants cultivated in constructed wetland systems

    Directory of Open Access Journals (Sweden)

    Gheila Corrêa Ferres Baptestini

    2016-01-01

    Full Text Available The objective of the present study was to evaluate the effect of reversal of the flow direction, when used the surface flow as an operating criteria, on hydrodynamic characteristics and plants grown in horizontal subsurface-flow constructed wetland systems (HSF-CWs. For this purpose, six HSF-CWs were used: two non-cultivated (HSF-CWs 1 and 4, two cultivated with Tifton 85 grass (Cynodon spp. (HSF-CWs 2 and 5 and two cultivated with Alternanthera (Alternanthera philoxeroides (HSF-CWs 3 and 6. It was made a reversal in the flow direction of the HSF-CWs 1, 2 and 3. The reversal of the wastewater flow direction was performed when the superficial flow of the wastewater applied (SF reached 50% of the length of the HSF-CWs. There was a single reversal for each system, on different dates. Reversing the flow direction promoted distinction on the dry matter yield of Tifton 85 grass. This was not observed in HSF-CWs cultivated with Alternanthera. The reversal of the wastewater flow direction promoted, in principle, the extinction of the SF advance in the HSF-CWs, but did not prevent its return. Waiting for the SF to reach 50% of the length was not the best criterion for reversing the flow direction.

  5. Socioeconomic aspects of agroforesty systems: the case of gum-cultivation cycle

    International Nuclear Information System (INIS)

    Sharawi, H. A.

    2010-01-01

    The purpose of the study was to attempt to understand the nature of the problems related to production and local marketing of gum arabic as been by producers and local traders. Using structural questionnaires and multistage stratified sampling, data were collected on economic activities, production and productivity, price and pricing policy and marketing and trade as well as services provided to producers. Statistical analysis was carried out using various descriptive methods including means and means comparisons. The results indicated a general declining trend of the areas trapped by households. Productivity per unit area, prices received by producers and different from of services during the period covered by the study. The level of the producer's price seems to be the most important socioeconomic factor affecting the decision to produce. The need for institutions that are more effective and of services that promote production and marketing were seen as essential. The results have important implications on pricing policies and sustain ability of the gum-cultivation cycle as an integrated management system in the gum belt of the Sudan.(Author)

  6. WATER RETENTION OPTION OF DRAINAGE SYSTEM FOR DRY SEASON CORN CULTIVATION AT TIDAL LOWLAND AREA

    Directory of Open Access Journals (Sweden)

    Bakri

    2015-10-01

    Full Text Available Farming constraint at tidal lowland area is about water management related to the nature of excessive water during wet season and insufficient water during dry season. This field research objectives was to find out the corn crop cultivation in August 2014 which entered dry season. The installation of subsurface drainage that previously had functioned as water discharge was converted into water retention. The research results showed that corn had grown well during peak dry season period (October in which water table was at –50 cm below soil surface, whereas water table depth was dropped to –70 cm below soil surface in land without subsurface drainage. This condition implied that installation of subsurface drainage at dry season had function as water retention, not as water discharge. Therefore, network function was inverted from water discharge into water retention. It had impact on the development of optimum water surface that flow in capillary mode to fulfill the crop’s water requirement. Corn production obtained was 6.4 t ha-1. This condition was very promising though still below the maximum national production. The applications of subsurface drainage was still not optimum due to the supply of water from the main system was not the same because of the soil physical properties diversity and topography differences.

  7. Comparison of two possible routes of pathogen contamination of spinach leaves in a hydroponic cultivation system.

    Science.gov (United States)

    Koseki, Shigenobu; Mizuno, Yasuko; Yamamoto, Kazutaka

    2011-09-01

    The route of pathogen contamination (from roots versus from leaves) of spinach leaves was investigated with a hydroponic cultivation system. Three major bacterial pathogens, Escherichia coli O157:H7, Salmonella, and Listeria monocytogenes, were inoculated into the hydroponic solution, in which the spinach was grown to give concentrations of 10⁶ and 10³ CFU/ml. In parallel, the pathogens were inoculated onto the growing leaf surface by pipetting, to give concentrations of 10⁶ and 10³ CFU per leaf. Although contamination was observed at a high rate through the root system by the higher inoculum (10⁶ CFU) for all the pathogens tested, the contamination was rare when the lower inoculum (10³ CFU) was applied. In contrast, contamination through the leaf occurred at a very low rate, even when the inoculum level was high. For all the pathogens tested in the present study, the probability of contamination was promoted through the roots and with higher inoculum levels. The probability of contamination was analyzed with logistic regression. The logistic regression model showed that the odds ratio of contamination from the roots versus from the leaves was 6.93, which suggested that the risk of contamination from the roots was 6.93 times higher than the risk of contamination from the leaves. In addition, the risk of contamination by L. monocytogenes was about 0.3 times that of Salmonella enterica subsp. enterica serovars Typhimurium and Enteritidis and E. coli O157:H7. The results of the present study indicate that the principal route of pathogen contamination of growing spinach leaves in a hydroponic system is from the plant's roots, rather than from leaf contamination itself.

  8. From hybridomas to a robust microalgal-based production platform: molecular design of a diatom secreting monoclonal antibodies directed against the Marburg virus nucleoprotein.

    Science.gov (United States)

    Hempel, Franziska; Maurer, Michael; Brockmann, Björn; Mayer, Christian; Biedenkopf, Nadine; Kelterbaum, Anne; Becker, Stephan; Maier, Uwe G

    2017-07-27

    The ideal protein expression system should provide recombinant proteins in high quality and quantity involving low production costs only. However, especially for complex therapeutic proteins like monoclonal antibodies many challenges remain to meet this goal and up to now production of monoclonal antibodies is very costly and delicate. Particularly, emerging disease outbreaks like Ebola virus in Western Africa in 2014-2016 make it necessary to reevaluate existing production platforms and develop robust and cheap alternatives that are easy to handle. In this study, we engineered the microalga Phaeodactylum tricornutum to produce monoclonal IgG antibodies against the nucleoprotein of Marburg virus, a close relative of Ebola virus causing severe hemorrhagic fever with high fatality rates in humans. Sequences for both chains of a mouse IgG antibody were retrieved from a murine hybridoma cell line and implemented in the microalgal system. Fully assembled antibodies were shown to be secreted by the alga and antibodies were proven to be functional in western blot, ELISA as well as IFA studies just like the original hybridoma produced IgG. Furthermore, synthetic variants with constant regions of a rabbit IgG and human IgG with optimized codon usage were produced and characterized. This study highlights the potential of microalgae as robust and low cost expression platform for monoclonal antibodies secreting IgG antibodies directly into the culture medium. Microalgae possess rapid growth rates, need basically only water, air and sunlight for cultivation and are very easy to handle.

  9. Improving farming practices using multi-criteria decision analysis in geographic information system for Damask Rose cultivating

    Directory of Open Access Journals (Sweden)

    B. Shokati

    2016-12-01

    Full Text Available Lack of awareness of the critical factors involved in production of plants and sometimes, the cultivation of plants in areas unsusceptible to plant, can increase the amount of chemical fertilizer consumption in order to compensate the subsequent reduction of plant yield. This would increase environmental pollution. Thus, identifying of suitable areas where could supply plants initial needs of the environment is critical. For this goal, several criteria including soil conditions, climatologically indicators, topography situation and agro-climatology criteria were taken into account of modeling processing. Doing so, standardization process was performed on criteria and weighting process was performed by using of analytic hierarchy process approach. Geographical information system based on multi-criteria decision analysis was employed for weighted overlapping of indicators. Initial results indicated that East-Azerbaijan Province in the northern part of Iran has high potential for cultivating of Damask Rose. Results indicate that about 34.4% of East Azerbaijan Province has classified to be high suitability for cultivating this plant, while about 65.5 and 0.1 % of this area classified to be in the moderate and low suitability category respectively. In comparison of Damask Rose production during the 2014 and resulted analytic hierarchy process map results showed that areas with high suitability are not more under cultivation of this plant. Then, the findings of this study are great of importance for the purpose of regional planning in East-Azerbaijan Province.

  10. Morphology and muscle gene expression in GIFT and Supreme Nile tilapia varieties reared in two cultivation systems.

    Science.gov (United States)

    Lima, E C S; Povh, J A; Otonel, R A A; Leonhardt, J H; Alfieri, A A; Headley, S A; Souza, F P; Poveda-Parra, A R; Furlan-Murari, P J; Lopera-Barrero, N M

    2017-03-16

    Tissue growth in most fishes occurs by muscular hyperplasia and hypertrophy, which are influenced by different regulatory factors, such as myostatin. The current study evaluated the influence of cultivation in hapas and earthen ponds on the diameter of white muscle fibers and on the myostatin (MSTN-1) gene in GIFT and Supreme varieties of tilapia. Fish of both varieties were reared for 204 days and then divided into four developmental stages. White muscle samples, corresponding to 100 fibers per slide, were collected from the middle region of fish of each variety and cultivation system, and were measured and divided into two classes representing hyperplasia and hypertrophy. Samples were subjected to real-time PCR to analyze gene expression. Hyperplasia decreased during the developing stages, coupled with increased hypertrophy. There was a higher rate of hypertrophy in fish raised in earthen ponds when compared to those raised in hapas, during juvenile and developing phases, and greater hypertrophic growth was observed in GIFT specimens when compared to Supreme specimens in earthen ponds. Since increased MSTN-1 gene expression was observed in GIFT specimens during the developing phase in pond cultivations, and in Supreme tilapia in hapas, MSTN-1 expression is related to greater hypertrophy. These results demonstrate the capacity for increased muscle growth in earthen pond cultivation in which the GIFT variety developed best. How the environment affects the growth of different tilapia varieties may be employed to optimize culture management and genetic improvement programs. Further investigations should aim to describe mechanisms affecting muscle growth and development.

  11. A dual-species co-cultivation system to study the interactions between Roseobacters and Dinoflagellates

    Directory of Open Access Journals (Sweden)

    Hui eWang

    2014-06-01

    Full Text Available Some microalgae in nature live in symbiosis with microorganisms that can enhance or inhibit growth, thus influencing the dynamics of phytoplankton blooms. In spite of the great ecological importance of these interactions, very few defined laboratory systems are available to study them in detail. Here we present a co-cultivation system consisting of the toxic phototrophic dinoflagellate Prorocentrum minimum and the photoheterotrophic alphaproteobacterium Dinoroseobacter shibae. In a mineral medium lacking a carbon source, vitamins for the bacterium and the essential vitamin B12 for the dinoflagellate, growth dynamics reproducibly went from a mutualistic phase, where both algae and bacteria grow, to a pathogenic phase, where the algae are killed by the bacteria. The data show a Jekyll and Hyde lifestyle that had been proposed but not previously demonstrated. We used RNAseq and microarray analysis to determine which genes of D. shibae are transcribed and differentially expressed in a light dependent way at an early time-point of the co-culture when the bacterium grows very slowly. Enrichment of bacterial mRNA for transcriptome analysis was optimized, but none of the available methods proved capable of removing dinoflagellate ribosomal RNA completely. RNAseq showed that a phasin encoding gene (phaP1 which is part of the polyhydroxyalkanoate (PHA metabolism operon represented approximately 10 % of all transcripts. Five genes for aerobic anoxygenic photosynthesis were down-regulated in the light, indicating that the photosynthesis apparatus was functional. A betaine-choline-carnitine-transporter (BCCT that may be used for dimethylsulfoniopropionate (DMSP uptake was the highest up-regulated gene in the light. The data suggest that at this early mutualistic phase of the symbiosis, PHA degradation might be the main carbon and energy source of D. shibae, supplemented in the light by degradation of DMSP and aerobic anoxygenic photosynthesis.

  12. A novel customizable modular bioreactor system for whole-heart cultivation under controlled 3D biomechanical stimulation.

    Science.gov (United States)

    Hülsmann, Jörn; Aubin, Hug; Kranz, Alexander; Godehardt, Erhardt; Munakata, Hiroshi; Kamiya, Hiroyuki; Barth, Mareike; Lichtenberg, Artur; Akhyari, Payam

    2013-09-01

    In the last decade, cardiovascular tissue engineering has made great progress developing new strategies for regenerative medicine applications. However, while tissue engineered heart valves are already entering the clinical routine, tissue engineered myocardial substitutes are still restrained to experimental approaches. In contrast to the heart valves, tissue engineered myocardium cannot be repopulated in vivo because of its biological complexity, requiring elaborate cultivation conditions ex vivo. Although new promising approaches-like the whole-heart decellularization concept-have entered the myocardial tissue engineering field, bioreactor technology needed for the generation of functional myocardial tissue still lags behind in the sense of user-friendly, flexible and low cost systems. Here, we present a novel customizable modular bioreactor system that can be used for whole-heart cultivation. Out of a commercially obtainable original equipment manufacturer platform we constructed a modular bioreactor system specifically aimed at the cultivation of decellularized whole-hearts through perfusion and controlled 3D biomechanical stimulation with a simple but highly flexible operation platform based on LabVIEW. The modular setup not only allows a wide range of variance regarding medium conditioning under controlled 3D myocardial stretching but can also easily be upgraded for e.g. electrophysiological monitoring or stimulation, allowing for a tailor-made low-cost myocardial bioreactor system.

  13. Determination of volumetric gas-liquid mass transfer coefficient of carbon monoxide in a batch cultivation system using kinetic simulations.

    Science.gov (United States)

    Jang, Nulee; Yasin, Muhammad; Park, Shinyoung; Lovitt, Robert W; Chang, In Seop

    2017-09-01

    A mathematical model of microbial kinetics was introduced to predict the overall volumetric gas-liquid mass transfer coefficient (k L a) of carbon monoxide (CO) in a batch cultivation system. The cell concentration (X), acetate concentration (C ace ), headspace gas (N co and [Formula: see text] ), dissolved CO concentration in the fermentation medium (C co ), and mass transfer rate (R) were simulated using a variety of k L a values. The simulated results showed excellent agreement with the experimental data for a k L a of 13/hr. The C co values decreased with increase in cultivation times, whereas the maximum mass transfer rate was achieved at the mid-log phase due to vigorous microbial CO consumption rate higher than R. The model suggested in this study may be applied to a variety of microbial systems involving gaseous substrates. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Rice cultivation in the farming systems of Sukumaland, Tanzania : a quest for sustainable production under structural adjustment programmes

    OpenAIRE

    Meertens, H.C.C.

    1999-01-01

    This thesis investigates options for sustainable rice cultivation and general agricultural development in the Mwanza and Shinyanga regions in northwestern Tanzania, often called Sukumaland due to the predominance of Wasukuma people. Generally Sukumaland has a semi-arid climate; agriculture is constrained by unreliable and low rainfall. In the past fifty years the population density has doubled in most parts. This has triggered several changes in farming systems. One important change ...

  15. Superstructure optimization of biodiesel production from microalgal biomass

    DEFF Research Database (Denmark)

    Rizwan, Muhammad; Lee, Jay H.; Gani, Rafiqul

    2013-01-01

    In this study, we propose a mixed integer nonlinear programming (MINLP) model for superstructure based optimization of biodiesel production from microalgal biomass. The proposed superstructure includes a number of major processing steps for the production of biodiesel from microalgal biomass...... for the production of biodiesel from microalgae. The proposed methodology is tested by implementing on a specific case study. The MINLP model is implemented and solved in GAMS using a database built in Excel. The results from the optimization are analyzed and their significances are discussed....

  16. Variation in soil fertility influences cycle dynamics and crop diversity in shifting cultivation systems

    NARCIS (Netherlands)

    Braga Junqueira, A.; Stomph, T.J.; Clement, C.R.; Struik, P.C.

    2016-01-01

    Smallholder farming in Amazonia is practised mostly through shifting cultivation, which under low population pressure is well adapted to the low-fertility soils that predominate in uplands and to the lack of external inputs. In this paper we investigate the effects of soil heterogeneity (in terms of

  17. [Cultivated keratinocytes on micro-carriers: in vitro studies of a new carrier system].

    Science.gov (United States)

    Hecht, J; Hoefter, E A; Hecht, J; Haraida, S; Nerlich, A; Hartinger, A; Mühlbauer, W; Dimoudis, N

    1997-03-01

    Epidermal grafts from confluently cultivated keratinocytes have been used since the early eighties for the treatment of severe burns, where the shortage of donor sites for split-thickness skin grafts did not allow for adequate wound coverage. The difficult handling of these grafts as well as the advanced differentiation of their epithelial cells into a multilayer sheet poses a problem for their clinical application. The aim of the study was to characterize cultivated keratinocytes, as well as to observe their migration and proliferation from the MC onto a surface. Keratinocytes were isolated from human foreskin and cultivated in serum-free and serum-containing medium according to a modified method by Rheinwald and Green. Collagen-coated Dextran beads were used as MC. The MC were colonized with keratinocytes using the Spinner culture technique. After seeding the colonized MC into culture flasks, their migration and proliferation was monitored regularly through immunohistochemical studies and measurement of the metabolic cell activity. Immunohistological staining proved that the cells isolated from human foreskin represent keratinocytes of the basal type. Keratinocytes, cultivated with serum-containing and serum free medium, both adhered to the surface of the MC, then migrated onto the surface of the flasks and proliferated to form a multilayer of epithelial cells. In the long-term, a flexible epithelial graft consisting of poorly differentiated keratinocytes should be available, which is simple to produce and easy to handle. This would be an alternative method for treating wounds, where the conventional multilayer epithelial graft (ET) is insufficient.

  18. Study of the evolution of nitrogen compounds during grape ripening. application to differentiate grape varieties and cultivated systems.

    Science.gov (United States)

    Garde-Cerdán, Teresa; Lorenzo, Cándida; Lara, José Félix; Pardo, Francisco; Ancín-Azpilicueta, Carmen; Salinas, M Rosario

    2009-03-25

    The aim of this work was to study the evolution of amino acids and ammonium during grape ripening and to evaluate its application to differentiate grape varieties and cultivated systems (organic and nonorganic). For this purpose, Monastrell, Syrah, Merlot, and Petit Verdot grapes produced using conventional agriculture and Monastrell grape cultivated using organic agriculture, collected during two consecutive harvests at different stages of ripening, were studied. These years of harvest were very different climatic years; even so, the grape varieties presented similar qualitative compositions. Therefore, the percentage of amino acids at harvest moment allowed differentiation of grapes according to variety and cultivated system, regardless of the year. The nitrogen composition could allow estimation of the fermentative aroma potential of grapes. Thus, Syrah was the grape with the greatest aroma potential at harvest. Monastrell nonorganic grape had a concentration of nitrogen compounds superior to that of Monastrell organic grape. In Monastrell, Syrah, and Merlot, traditional varieties in the area, the highest concentration of nitrogen compounds coincided with the highest degrees Baume/total acidity ratio and color index during 2007. Consequently, technological and phenolic maturity of these grape varieties coincided with the maximum composition of nitrogen compounds. However, in 2008, this did not happen because grape ripening was irregular as a consequence of different climatological conditions.

  19. Chemicals to enhance microalgal growth and accumulation of high-value bioproducts

    Directory of Open Access Journals (Sweden)

    Xinheng eYu

    2015-02-01

    Full Text Available Photosynthetic microalgae have attracted significant attention as they can serve as important sources for cosmetic, food and pharmaceutical products, industrial materials and even biofuel biodiesels. However, current productivity of microalga-based processes is still very low, which has restricted their scale-up application. In addition to various efforts in strain improvement and cultivation optimization, it was proposed that the productivity of microalga-based processes can also be increased using various chemicals to trigger or enhance cell growth and accumulation of bioproducts. Herein, we summarized recent progresses in applying chemical triggers or enhancers to improve cell growth and accumulation of bioproducts in algal cultures. Based on their enhancing mechanisms, these chemicals can be classified into four categories:chemicals regulating biosynthetic pathways, chemicals inducing oxidative stress responses, phytohormones and analogues regulating multiple aspects of microalgal metabolism, and chemicals directly as metabolic precursors. Taken together, the early researches demonstrated that the use of chemical stimulants could be a very effective and economical way to improve cell growth and accumulation of high-value bioproducts in large-scale cultivation of microalgae.

  20. Regulations for marine microalgal toxins: Towards harmonization of ...

    African Journals Online (AJOL)

    The World Trade Organization and the General Agreements on Tariffs and Trade encourage the harmonization of regulations on food safety requirements. The current policy on trade liberalization of seafood is presented, together with a review of the regulations for marine microalgal toxins. Activities on harmonization of ...

  1. Crustacean fauna of a mussel cultivated raft system in the Black Sea

    Directory of Open Access Journals (Sweden)

    Murat Sezgin

    2013-06-01

    Full Text Available The aim of the current study was to make a faunistic analysis of the crustaceans associated with cultivated mussels grown on ropes. Mussel samples from 30 cm ropes were collected from rope-grown mussel beds by hand. The crustacean fauna associated with mussel population were quantified. The density of crustacean fauna associated with mussels was significantly greater within rope-grown mussel assemblages than on other biotopes around.

  2. A system dynamics approach to the study of Colombian coca cultivation and the counter-intuitive consequence of law enforcement.

    Science.gov (United States)

    Jaén, Sebastian; Dyner, Isaac

    2014-03-01

    A large-scale expansion of the Colombian coca cultivation is one of the most revealing signs of a structural change in the illegal cocaine market in the Andean region. From being a modest and domestic production, in the space of five years Colombian coca cultivation supplied a competitive market, capable of substituting almost completely the foreign sources of supply. The purpose of this work is to explore the role and potential of system dynamics (SD) as a modeling methodology to better understand the consequences of drug policy. As a case study, this work tests the hypothesis that the outbreak of Colombian coca cultivations is a consequence of the take down of large cartels, leading to the surge of small drug-trafficking firms called "cartelitos." Using an SD model, and elements from the economic theory of the criminal firm, our work shows how the formation of these small firms might significantly contribute to the configuring of a more competitive domestic coca industry (and hence to a more efficient crime industry). We conclude that SD seems an appropriate dynamic modeling-based approach to address policy issues regarding drug markets. The methodology takes into account the dynamic nature of drug markets and their multi-dimensional responses to policy interventions. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Analysis of Selected Environmental Indicators in the Cultivation System of Energy Crops

    Directory of Open Access Journals (Sweden)

    Šoltysová Božena Š

    2017-11-01

    Full Text Available The changes of selected chemical parameters were observed in Gleyic Fluvisols. The field experiment was established as a twofactor experiment with four energy crops (Arundo donax L., Miscanthus × giganteus, Elymus elongatus Gaertner, Sida hermafrodita and two variants of fertilization (nitrogen fertilization in rate 60 kg ha-1, without nitrogen fertilization. Soil samples were taken from the depth of 0 to 0.3 m at the beginning of the experiment in the autumn 2012 and at the end of reference period in the autumn 2015. Land management conversion from market crops to perennial energy crops cultivation has influenced changes of selected soil chemical parameters. The contents of soil organic carbon were affected by cultivated energy crops differently. It was found out that Arundo increased the organic carbon content and Miscanthus, Elymus and Sida decreased its content. At the same time, the same impact of the crops on content of available phosphorus and potassium and soil reaction was found. It was recorded that each cultivated crop decreased the soil reaction and available phosphorus content and increased the content of available potassium.

  4. Changes in the Diversity of Soil Arbuscular Mycorrhizal Fungi after Cultivation for Biofuel Production in a Guantanamo (Cuba) Tropical System

    Science.gov (United States)

    Alguacil, Maria del Mar; Torrecillas, Emma; Hernández, Guillermina; Roldán, Antonio

    2012-01-01

    The arbuscular mycorrhizal fungi (AMF) are a key, integral component of the stability, sustainability and functioning of ecosystems. In this study, we characterised the AMF biodiversity in a native vegetation soil and in a soil cultivated with Jatropha curcas or Ricinus communis, in a tropical system in Guantanamo (Cuba), in order to verify if a change of land use to biofuel plant production had any effect on the AMF communities. We also asses whether some soil properties related with the soil fertility (total N, Organic C, microbial biomass C, aggregate stability percentage, pH and electrical conductivity) were changed with the cultivation of both crop species. The AM fungal small sub-unit (SSU) rRNA genes were subjected to PCR, cloning, sequencing and phylogenetic analyses. Twenty AM fungal sequence types were identified: 19 belong to the Glomeraceae and one to the Paraglomeraceae. Two AMF sequence types related to cultured AMF species (Glo G3 for Glomus sinuosum and Glo G6 for Glomus intraradices-G. fasciculatum-G. irregulare) did not occur in the soil cultivated with J. curcas and R. communis. The soil properties (total N, Organic C and microbial biomass C) were higher in the soil cultivated with the two plant species. The diversity of the AMF community decreased in the soil of both crops, with respect to the native vegetation soil, and varied significantly depending on the crop species planted. Thus, R. communis soil showed higher AMF diversity than J. curcas soil. In conclusion, R. communis could be more suitable for the long-term conservation and sustainable management of these tropical ecosytems. PMID:22536339

  5. Changes in the diversity of soil arbuscular mycorrhizal fungi after cultivation for biofuel production in a Guantanamo (Cuba tropical system.

    Directory of Open Access Journals (Sweden)

    Maria del Mar Alguacil

    Full Text Available The arbuscular mycorrhizal fungi (AMF are a key, integral component of the stability, sustainability and functioning of ecosystems. In this study, we characterised the AMF biodiversity in a native vegetation soil and in a soil cultivated with Jatropha curcas or Ricinus communis, in a tropical system in Guantanamo (Cuba, in order to verify if a change of land use to biofuel plant production had any effect on the AMF communities. We also asses whether some soil properties related with the soil fertility (total N, Organic C, microbial biomass C, aggregate stability percentage, pH and electrical conductivity were changed with the cultivation of both crop species. The AM fungal small sub-unit (SSU rRNA genes were subjected to PCR, cloning, sequencing and phylogenetic analyses. Twenty AM fungal sequence types were identified: 19 belong to the Glomeraceae and one to the Paraglomeraceae. Two AMF sequence types related to cultured AMF species (Glo G3 for Glomus sinuosum and Glo G6 for Glomus intraradices-G. fasciculatum-G. irregulare did not occur in the soil cultivated with J. curcas and R. communis. The soil properties (total N, Organic C and microbial biomass C were higher in the soil cultivated with the two plant species. The diversity of the AMF community decreased in the soil of both crops, with respect to the native vegetation soil, and varied significantly depending on the crop species planted. Thus, R. communis soil showed higher AMF diversity than J. curcas soil. In conclusion, R. communis could be more suitable for the long-term conservation and sustainable management of these tropical ecosytems.

  6. A simple, reproducible and sensitive spectrophotometric method to estimate microalgal lipids

    Energy Technology Data Exchange (ETDEWEB)

    Chen Yimin [ChELSI Institute, Department of Chemical and Biological Engineering, University of Sheffield, Sheffield S1 3JD (United Kingdom); Vaidyanathan, Seetharaman, E-mail: s.vaidyanathan@sheffield.ac.uk [ChELSI Institute, Department of Chemical and Biological Engineering, University of Sheffield, Sheffield S1 3JD (United Kingdom)

    2012-04-29

    Highlights: Black-Right-Pointing-Pointer FAs released from lipids form complex with Cu-TEA in chloroform. Black-Right-Pointing-Pointer The FA-Cu-TEA complex gives strong absorbance at 260 nm. Black-Right-Pointing-Pointer The absorbance is sensitive and independent of C-atom number in the FAs (10-18). Black-Right-Pointing-Pointer Microalgal lipid extract and pure FA (such as C16) can both be used as standards. - Abstract: Quantification of total lipids is a necessity for any study of lipid production by microalgae, especially given the current interest in microalgal carbon capture and biofuels. In this study, we employed a simple yet sensitive method to indirectly measure the lipids in microalgae by measuring the fatty acids (FA) after saponification. The fatty acids were reacted with triethanolamine-copper salts (TEA-Cu) and the ternary TEA-Cu-FA complex was detected at 260 nm using a UV-visible spectrometer without any colour developer. The results showed that this method could be used to analyse low levels of lipids in the range of nano-moles from as little as 1 mL of microalgal culture. Furthermore, the structure of the TEA-Cu-FA complex and related reaction process are proposed to better understand this assay. There is no special instrument required and the method is very reproducible. To the best of our knowledge, this is the first report of the use of UV absorbance of copper salts with FA as a method to estimate lipids in algal cultures. It will pave the way for a more convenient assay of lipids in microalgae and can readily be expanded for estimating lipids in other biological systems.

  7. A simple, reproducible and sensitive spectrophotometric method to estimate microalgal lipids

    International Nuclear Information System (INIS)

    Chen Yimin; Vaidyanathan, Seetharaman

    2012-01-01

    Highlights: ► FAs released from lipids form complex with Cu–TEA in chloroform. ► The FA–Cu–TEA complex gives strong absorbance at 260 nm. ► The absorbance is sensitive and independent of C-atom number in the FAs (10–18). ► Microalgal lipid extract and pure FA (such as C16) can both be used as standards. - Abstract: Quantification of total lipids is a necessity for any study of lipid production by microalgae, especially given the current interest in microalgal carbon capture and biofuels. In this study, we employed a simple yet sensitive method to indirectly measure the lipids in microalgae by measuring the fatty acids (FA) after saponification. The fatty acids were reacted with triethanolamine–copper salts (TEA–Cu) and the ternary TEA–Cu–FA complex was detected at 260 nm using a UV–visible spectrometer without any colour developer. The results showed that this method could be used to analyse low levels of lipids in the range of nano-moles from as little as 1 mL of microalgal culture. Furthermore, the structure of the TEA–Cu–FA complex and related reaction process are proposed to better understand this assay. There is no special instrument required and the method is very reproducible. To the best of our knowledge, this is the first report of the use of UV absorbance of copper salts with FA as a method to estimate lipids in algal cultures. It will pave the way for a more convenient assay of lipids in microalgae and can readily be expanded for estimating lipids in other biological systems.

  8. Non-invasive rapid harvest time determination of oil-producing microalgae cultivations for bio-diesel production by using Chlorophyll fluorescence

    Directory of Open Access Journals (Sweden)

    Yaqin eQiao

    2015-10-01

    Full Text Available For the large-scale cultivation of microalgae for biodiesel production, one of the key problems is the determination of the optimum time for algal harvest when algae cells are saturated with neutral lipids. In this study, a method to determine the optimum harvest time in oil-producing microalgal cultivations by measuring the maximum photochemical efficiency of photosystem II (PSII, also called Fv/Fm, was established. When oil-producing Chlorella strains were cultivated and then treated with nitrogen starvation, it not only stimulated neutral lipid accumulation, but also affected the photosynthesis system, with the neutral lipid contents in all four algae strains – Chlorella sorokiniana C1, Chlorella sp. C2, C. sorokiniana C3, C. sorokiniana C7 – correlating negatively with the Fv/Fm values. Thus, for the given oil-producing algae, in which a significant relationship between the neutral lipid content and Fv/Fm value under nutrient stress can be established, the optimum harvest time can be determined by measuring the value of Fv/Fm. It is hoped that this method can provide an efficient way to determine the harvest time rapidly and expediently in large-scale oil-producing microalgae cultivations for biodiesel production.

  9. Comparative life cycle assessment of real pilot reactors for microalgae cultivation in different seasons

    International Nuclear Information System (INIS)

    Pérez-López, Paula; De Vree, Jeroen H.; Feijoo, Gumersindo; Bosma, Rouke; Barbosa, Maria J.; Moreira, María Teresa; Wijffels, René H.; Van Boxtel, Anton J.B.; Kleinegris, Dorinde M.M.

    2017-01-01

    Highlights: •Life cycle assessment was used to compare 3 real pilot systems for algae cultivation. •The temperature control system was the main contributor to environmental impacts. •Tubular reactors had lower impacts per unit of biomass produced than open pond. •Meteorological conditions on the reactors played a critical role in LCA results. •Environmental impact reductions of 17–90% were estimated for optimized full-scale reactors. -- Abstract: Microalgae are promising natural resources for biofuels, chemical, food and feed products. Besides their economic potential, the environmental sustainability must be examined. Cultivation has a significant environmental impact that depends on reactor selection and operating conditions. To identify the main environmental bottlenecks for scale-up to industrial facilities this study provides a comparative life cycle assessment (LCA) of open raceway ponds and tubular photobioreactors at pilot scale. The results are based on experimental data from real pilot plants operated in summer, fall and winter at AlgaePARC (Wageningen, The Netherlands). The energy consumption for temperature regulation presented the highest environmental burden. The production of nutrients affected some categories. Despite limited differences compared to the vertical system, the horizontal PBR was found the most efficient in terms of productivity and environmental impact. The ORP was, given the Dutch climatic conditions, only feasible under summer operation. The results highlight the relevance of LCA as a tool for decision-making in process design. Weather conditions and availability of sources for temperature regulation were identified as essential factors for the selection of geographic locations and for microalgal cultivation systems based on environmental criteria. Simulation of large-scale reactors with optimized temperature regulation systems lead to environmental improvements and energy demand reductions ranging from 17% up to 90% for

  10. Development of air conditioning system and labor saving technology for efficient hydroponic cultivation; Konoritsuna suiko saibai no tame no kucho to shoryokuka gijutsu no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Okano, T.; Terazoe, H.; Shoji, K. [Central Research Institute of Electric Power Industry, Tokyo (Japan); Yonezawa, K.; Otani, F. [Chugoku Electric Power Co. Inc., Hiroshima (Japan); Sekiyama, T.; Kosakai, K.; Sato, H.

    1997-06-01

    Equipment which made experiments on air conditioning and hydroponic cultivation possible was set up at the technical research center of the Chugoku Electric Power Co., to study an air conditioning system using night power and energy saving technology for the cultivation. Vegetables suitable to the cultivation were selected. For air conditioning, adopted was a water heat storage air conditioning system using night power. The space between the shade curtain and the greenhouse roof was ventilated to prevent increase in cooling load caused by rise in curtain temperature. Moreover, the cultivation equipment was covered with transparent vinyl film to cool the inside of the equipment. The hydroponic cultivation equipment was trially manufactured which makes the continued production by one worker possible. The cultivation of spinach, leaf lettuce and chingensai throughout the year became possible. The yield of chingensai reached the target, but those of spinach and leaf lettuce were approximately 70% of the targets. Vegetables to be produced in the air-conditioned greenhouse by hydroponic cultivation are thought to be those that can have added values such non-pesticides and ingredients, young plants which were increased by cutting or tissue culturing, etc. 5 refs., 19 figs., 8 tabs.

  11. Research on cultivating medical students' self-learning ability using teaching system integrated with learning analysis technology.

    Science.gov (United States)

    Luo, Hong; Wu, Cheng; He, Qian; Wang, Shi-Yong; Ma, Xiu-Qiang; Wang, Ri; Li, Bing; He, Jia

    2015-01-01

    Along with the advancement of information technology and the era of big data education, using learning process data to provide strategic decision-making in cultivating and improving medical students' self-learning ability has become a trend in educational research. Educator Abuwen Toffler said once, the illiterates in the future may not be the people not able to read and write, but not capable to know how to learn. Serving as educational institutions cultivating medical students' learning ability, colleges and universities should not only instruct specific professional knowledge and skills, but also develop medical students' self-learning ability. In this research, we built a teaching system which can help to restore medical students' self-learning processes and analyze their learning outcomes and behaviors. To evaluate the effectiveness of the system in supporting medical students' self-learning, an experiment was conducted in 116 medical students from two grades. The results indicated that problems in self-learning process through this system was consistent with problems raised from traditional classroom teaching. Moreover, the experimental group (using this system) acted better than control group (using traditional classroom teaching) to some extent. Thus, this system can not only help medical students to develop their self-learning ability, but also enhances the ability of teachers to target medical students' questions quickly, improving the efficiency of answering questions in class.

  12. Irradiance optimization of outdoor microalgal cultures using solar tracked photobioreactors.

    Science.gov (United States)

    Hindersin, Stefan; Leupold, Marco; Kerner, Martin; Hanelt, Dieter

    2013-03-01

    Photosynthetic activity and temperature regulation of microalgal cultures (Chlorella vulgaris and Scenedesmus obliquus) under different irradiances controlled by a solar tracker and different cell densities were studied in outdoor flat panel photobioreactors. An automated process control unit regulated light and temperature as well as pH value and nutrient concentration in the culture medium. CO2 was supplied using flue gas from an attached combined block heat and power station. Photosynthetic activity was determined by pulse amplitude modulation fluorometry. Compared to the horizontal irradiance of 55 mol photons m(-2) d(-1) on a clear day, the solar tracked photobioreactors enabled a decrease and increase in the overall light absorption from 19 mol photons m(-2) d(-1) (by rotation out of direct irradiance) to 79 mol photons m(-2) d(-1) (following the position of the sun). At biomass concentrations below 1.1 g cell dry weight (CDW) L(-1), photoinhibition of about 35 % occurred at irradiances of ≥1,000 μmol photons m(-2) s(-1) photosynthetic active radiation (PAR). Using solar tracked photobioreactors, photoinhibition can be reduced and at optimum biomass concentration (≥2.3 g CDW L(-1)), the culture was irradiated up to 2,000 μmol photons m(-2) s(-1) to overcome light limitation with biomass yields of 0.7 g CDW mol photons(-1) and high photosynthetic activities indicated by an effective quantum yield of 0.68 and a maximum quantum yield of 0.80 (F v/F m). Overheating due to high irradiance was avoided by turning the PBR out of the sun or using a cooling system, which maintained the temperature close to the species-specific temperature optima.

  13. Lipid Production of Heterotrophic Chlorella sp. from Hydrolysate Mixtures of Lipid-Extracted Microalgal Biomass Residues and Molasses.

    Science.gov (United States)

    Zheng, Hongli; Ma, Xiaochen; Gao, Zhen; Wan, Yiqin; Min, Min; Zhou, Wenguang; Li, Yun; Liu, Yuhuan; Huang, He; Chen, Paul; Ruan, Roger

    2015-10-01

    This study investigated the feasibility of lipid production of Chlorella sp. from waste materials. Lipid-extracted microalgal biomass residues (LMBRs) and molasses were hydrolyzed, and their hydrolysates were analyzed. Five different hydrolysate mixture ratios (w/w) of LMBRs/molasses (1/0, 1/1, 1/4, 1/9, and 0/1) were used to cultivate Chlorella sp. The results showed that carbohydrate and protein were the two main compounds in the LMBRs, and carbohydrate was the main compound in the molasses. The highest biomass concentration of 5.58 g/L, Y biomass/sugars of 0.59 g/g, lipid productivity of 335 mg/L/day, and Y lipids/sugars of 0.25 g/g were obtained at the hydrolysate mixture ratio of LMBRs/molasses of 1/4. High C/N ratio promoted the conversion of sugars into lipids. The lipids extracted from Chlorella sp. shared similar lipid profile of soybean oil and is therefore a potential viable biodiesel feedstock. These results showed that Chlorella sp. can utilize mixed sugars and amino acids from LMBRs and molasses to accumulate lipids efficiently, thus reducing the cost of microalgal biodiesel production and improving its economic viability.

  14. Carbon Dioxide Mitigation by Microalgal Photosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Mijeong Lee; Gillis, James M.; Hwang, Jiann Yang [Michigan Technological University, Houghton (United States)

    2003-12-15

    Algal growth studies of Chlorella strains were conducted in a batch mode with bench type experiments. Carbon dioxide fixation rates of the following green microalgae were determined: Chlorella sp. H84, Chlorella sp. A2, Chlorella sorokiniana UTEX 1230, Chlorella vulgaris, and Chlorella pyrenoidosa. C. vulgaris, among other strains of microalgae, showed the highest growth rate (1.17 optical density/5 days). Cultivating conditions for C. vulgaris that produced the highest growth rate were at concentrations of 243 μg CO{sub 2}/mL, 10 mM ammonia, and 1 mM phosphate, with an initial pH range of 7-8.

  15. Use of geographic information systems (GIS to identify adequate sites for cultivation of the seaweed Gracilaria birdiae in Rio Grande do Norte, Northeastern Brazil

    Directory of Open Access Journals (Sweden)

    Flavo E. S. de Sousa

    2012-06-01

    Full Text Available This study was designed to select potential areas for cultivation of the seaweed Gracilaria birdiae Plastino & E.C. Oliveira (Gracilariales, Rhodophyta on the coast of Rio Grande do Norte state, Brazil. The Geographic Information System (GIS and multi-criteria evaluation (MCE were used to identify the most suitable areas. The Analytical Hierarchical Process (AHP was applied to establish MCE weights, thereby generating viable areas for species cultivation. From a total of 3316.82 ha, around 53.67% (1780.06 ha were indicated as highly suitable areas, 40.93% (1357.58 ha as moderately suitable and 5.40% (179.18 ha as scarcely suitable for seaweed cultivation. Seven areas (1084.62 ha are located on the northern coast and 20 (2232.20 ha on the eastern coast. The results show that GIS can be used as an effective instrument for selecting seaweed cultivation areas.

  16. Beneficial effect of compost utilization on reducing greenhouse gas emissions in a rice cultivation system through the overall management chain.

    Science.gov (United States)

    Jeong, Seung Tak; Kim, Gil Won; Hwang, Hyun Young; Kim, Pil Joo; Kim, Sang Yoon

    2018-02-01

    Livestock manure application can stimulate greenhouse gas (GHG) emissions, especially methane (CH 4 ) in rice paddy. The stabilized organic matter (OM) is recommended to suppress CH 4 emission without counting the additional GHG emission during the composting process. To evaluate the effect of compost utilization on the net global warming potential (GWP) of a rice cropping system, the fluxes of GHGs from composting to land application were calculated by a life cycle assessment (LCA) method. The model framework was composed of GHG fluxes from industrial activities and biogenic GHG fluxes from the composting and rice cultivation processes. Fresh manure emitted 30MgCO 2 -eq.ha -1 , 90% and 10% of which were contributed by CH 4 and nitrous oxide (N 2 O) fluxes, respectively, during rice cultivation. Compost utilization decreased net GWP by 25% over that of the fresh manure during the whole process. The composting process increased the GWP of the industrial processes by 35%, but the 60% reduction in CH 4 emissions from the rice paddy mainly influenced the reduction of GWP during the overall process. Therefore, compost application could be a good management strategy to reduce GHG emissions from rice paddy systems. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Evaluation of the cultivation of the lettuce (Lactuca sativa L. under organoponico and semi-protected systems

    Directory of Open Access Journals (Sweden)

    Dania Bárbara Núñez Sosa

    2015-03-01

    Full Text Available The research was done in the organoponico at the Soil Laboratory in Matanzas. The objective was to evaluate the response of the of the lettuce (Lactuca sativa, L. cultivation under conditions of organoponic and Semi-protected cultivation systems. Two varieties were studied: Fomento 95 and Black Seeded Simpson (BSS. The random block design was used. The data were processed using the Statgraphic plus 5.1 package for WINDOWS. The total number of leaves, number of commercial leaves, diameter of bush, yield in kg/m2, total content of soluble proteins and carbohydrates were evaluated. In conclusion, the variety Fomento 95 showed a significant increment of the total number of leaves in the organoponico system and commercial leaves with respect to the semi-protected conditions; the BSS variety showed only significant differences in commercial leaves; no significant differences in yield for both varieties were reported under the studied conditions. The analysis showed that the total soluble carbohydrates and proteins content decreased significantly in both varieties under semi-protected conditions.

  18. Do plastic particles affect microalgal photosynthesis and growth?

    Science.gov (United States)

    Sjollema, Sascha B; Redondo-Hasselerharm, Paula; Leslie, Heather A; Kraak, Michiel H S; Vethaak, A Dick

    2016-01-01

    The unbridled increase in plastic pollution of the world's oceans raises concerns about potential effects these materials may have on microalgae, which are primary producers at the basis of the food chain and a major global source of oxygen. Our current understanding about the potential modes and mechanisms of toxic action that plastic particles exert on microalgae is extremely limited. How effects might vary with particle size and the physico-chemical properties of the specific plastic material in question are equally unelucidated, but may hold clues to how toxicity, if observed, is exerted. In this study we selected polystyrene particles, both negatively charged and uncharged, and three different sizes (0.05, 0.5 and 6μm) for testing the effects of size and material properties. Microalgae were exposed to different polystyrene particle sizes and surface charges for 72h. Effects on microalgal photosynthesis and growth were determined by pulse amplitude modulation fluorometry and flow cytometry, respectively. None of the treatments tested in these experiments had an effect on microalgal photosynthesis. Microalgal growth was negatively affected (up to 45%) by uncharged polystyrene particles, but only at high concentrations (250mg/L). Additionally, these adverse effects were demonstrated to increase with decreasing particle size. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Using single cell cultivation system for on-chip monitoring of the interdivision timer in Chlamydomonas reinhardtii cell cycle

    Directory of Open Access Journals (Sweden)

    Soloviev Mikhail

    2010-09-01

    Full Text Available Abstract Regulation of cell cycle progression in changing environments is vital for cell survival and maintenance, and different regulation mechanisms based on cell size and cell cycle time have been proposed. To determine the mechanism of cell cycle regulation in the unicellular green algae Chlamydomonas reinhardtii, we developed an on-chip single-cell cultivation system that allows for the strict control of the extracellular environment. We divided the Chlamydomonas cell cycle into interdivision and division phases on the basis of changes in cell size and found that, regardless of the amount of photosynthetically active radiation (PAR and the extent of illumination, the length of the interdivision phase was inversely proportional to the rate of increase of cell volume. Their product remains constant indicating the existence of an 'interdivision timer'. The length of the division phase, in contrast, remained nearly constant. Cells cultivated under light-dark-light conditions did not divide unless they had grown to twice their initial volume during the first light period. This indicates the existence of a 'commitment sizer'. The ratio of the cell volume at the beginning of the division phase to the initial cell volume determined the number of daughter cells, indicating the existence of a 'mitotic sizer'.

  20. Removal of eutrophication factors and heavy metal from a closed cultivation system using the macroalgae, Gracilaria sp. (Rhodophyta)

    Science.gov (United States)

    Kang, Kyoung Ho; Sui, Zhenghong

    2010-11-01

    In this study, the ability of macroalgae Gracilaria sp. of removing eutrophication factors and toxic heavy metals Al, Cr, and Zn in a closed cultivation system is reported. The results show that the concentration of the three heavy metals decreased significantly during the experimental period in an algal biomass dependent manner. The biofiltration capacity of the alga for Al, Cr, and Zn is 10.1%-72.6%, 52.5%-83.4% and 36.5%-91.7%, respectively. Using more materials resulted in stronger heavy metal removal. Additionally, the concentration of chl- a, TN, TP and DIN of water samples from aquariums involving large, medium, and small algal biomass cultivation increased first and then decreased during the experiment. COD value of all three groups decreased with time and displayed algal biomass dependency: more algae resulting in a greater COD value than those of less biomass. Furthermore, changes in COD reflect an obvious organic particles deprivation process of algae. This is the first report on heavy metal removal effect by Gracilaria species. The results suggest that macroalgae can be used as a biofilter for the treatment of nutrient-enriched or heavy-metal polluted water, to which an appropriate time range should be carefully determined.

  1. Evaluation of the safety and efficacy of Glycyrrhiza uralensis root extracts produced using artificial hydroponic and artificial hydroponic-field hybrid cultivation systems.

    Science.gov (United States)

    Akiyama, H; Nose, M; Ohtsuki, N; Hisaka, S; Takiguchi, H; Tada, A; Sugimoto, N; Fuchino, H; Inui, T; Kawano, N; Hayashi, S; Hishida, A; Kudo, T; Sugiyama, K; Abe, Y; Mutsuga, M; Kawahara, N; Yoshimatsu, K

    2017-01-01

    Glycyrrhiza uralensis roots used in this study were produced using novel cultivation systems, including artificial hydroponics and artificial hydroponic-field hybrid cultivation. The equivalency between G. uralensis root extracts produced by hydroponics and/or hybrid cultivation and a commercial Glycyrrhiza crude drug were evaluated for both safety and efficacy, and there were no significant differences in terms of mutagenicity on the Ames tests. The levels of cadmium and mercury in both hydroponic roots and crude drugs were less than the limit of quantitation. Arsenic levels were lower in all hydroponic roots than in the crude drug, whereas mean lead levels in the crude drug were not significantly different from those in the hydroponically cultivated G. uralensis roots. Both hydroponic and hybrid-cultivated root extracts showed antiallergic activities against contact hypersensitivity that were similar to those of the crude drug extracts. These study results suggest that hydroponic and hybrid-cultivated roots are equivalent in safety and efficacy to those of commercial crude drugs. Further studies are necessary before the roots are applicable as replacements for the currently available commercial crude drugs produced from wild plant resources.

  2. NGT-3D: a simple nematode cultivation system to study Caenorhabditis elegans biology in 3D

    Directory of Open Access Journals (Sweden)

    Tong Young Lee

    2016-04-01

    Full Text Available The nematode Caenorhabditis elegans is one of the premier experimental model organisms today. In the laboratory, they display characteristic development, fertility, and behaviors in a two dimensional habitat. In nature, however, C. elegans is found in three dimensional environments such as rotting fruit. To investigate the biology of C. elegans in a 3D controlled environment we designed a nematode cultivation habitat which we term the nematode growth tube or NGT-3D. NGT-3D allows for the growth of both nematodes and the bacteria they consume. Worms show comparable rates of growth, reproduction and lifespan when bacterial colonies in the 3D matrix are abundant. However, when bacteria are sparse, growth and brood size fail to reach levels observed in standard 2D plates. Using NGT-3D we observe drastic deficits in fertility in a sensory mutant in 3D compared to 2D, and this defect was likely due to an inability to locate bacteria. Overall, NGT-3D will sharpen our understanding of nematode biology and allow scientists to investigate questions of nematode ecology and evolutionary fitness in the laboratory.

  3. [Progress in microalgae culture system for biodiesel combined with reducing carbon dioxide emission].

    Science.gov (United States)

    Su, Hongyang; Zhou, Xuefei; Xia, Xuefen; Sun, Zhen; Zhang, Yalei

    2011-09-01

    Wastewater resources, CO2 emission reduction and microalgae biodiesel are considered as current frontier fields of energy and environmental researches. In this paper, we reviewed the progress in system of microalgae culture for biodiesel production by wastewater and stack gas. Multiple factors including microalgal species, nutrition, culture methods and photobioreactor, which were crucial to the cultivation of microalgae for biodiesel production, were discussed in detail. A valuable culture system of microalgae for biodiesel production or other high value products combined with the treatment of wastewater by microalgae was put forward through the optimizations of algal species and culture technology. The culture system coupled with the treatment of wastewater, the reduction of CO2 emission with the cultivation of microalgae for biodiesel production will reduce the production cost of microalgal biofuel production and the treatment cost of wastewater simultaneously. Therefore, it would be a promising technology with important environmental value, social value and economic value to combine the treatment of wastewater with the cultivation of microalgae for biodiesel production.

  4. Characterization of a microalgal mutant for CO_2 biofixation and biofuel production

    International Nuclear Information System (INIS)

    Qi, Feng; Pei, Haiyan; Hu, Wenrong; Mu, Ruimin; Zhang, Shuo

    2016-01-01

    Highlights: • Combination of the isolation using 96-well microplates and traditional UV mutagenesis for screening HCT mutant. • Microalgal mutant Chlorella vulgaris SDEC-3M was screened out by modified UV mutagenesis. • SDEC-3M showed high CO_2 tolerance, high CO_2 requiring and relevant genetic stability. • LCE and carbohydrate content of SDEC-3M were significantly elevated. • SDEC-3M offers a strong candidature as CO_2 biofixation and biofuel production. - Abstract: In the present work, a Chlorella vulgaris mutant, named as SDEC-3M, was screened out through the combination of the isolation using 96-well microplates and traditional UV mutagenesis. Compared with its parent (wild type), the growth of SDEC-3M preferred higher CO_2 (15% v/v) environment to ambient air (0.038% CO_2 (v/v)), indicating that the mutant qualified with good tolerance and growth potential under high level CO_2 (high CO_2 tolerance) but was defective in directly utilizing the low level CO_2 (high CO_2 requiring). The genetic stability under ambient air and high level CO_2 was confirmed by a continuous cultivation for five generations. Higher light conversion efficiency (14.52%) and richer total carbohydrate content (42.48%) demonstrated that both solar energy and CO_2 were more effectively productively fixed into carbohydrates for bioethanol production than the parent strain. The mutant would benefit CO_2 biofixation from industrial exhaust gas to mitigate of global warming and promote biofuel production to relieve energy shortage.

  5. Bulk density of an alfisol under cultivation systems in a long-term experiment evaluated with gamma ray computed tomography

    International Nuclear Information System (INIS)

    Bamberg, Adilson Luis; Silva, Thiago Rech da; Pauletto, Eloy Antonio; Pinto, Luiz Fernando Spinelli; Lima, Ana Claudia Rodrigues de; Timm, Luis Carlos

    2009-01-01

    The sustainability of irrigated rice (Oryza sativa L.) in lowland soils is based on the use of crop rotation and succession, which are essential for the control of red and black rice. The effects on the soil properties deserve studies, particularly on soil compaction. The objective of this study was to identify compacted layers in an albaqualf under different cultivation and tillage systems, by evaluating the soil bulk density (Ds) with Gamma Ray Computed Tomography (TC). The analysis was carried out in a long-term experiment, from 1985 to 2004, at an experimental station of EMBRAPA Clima Temperado, Capao do Leao, RS, Brazil, in a random block design with seven treatments, with four replications (T1 - one year rice with conventional tillage followed by two years fallow; T2 - continuous rice under conventional tillage; T4 - rice and soybean (Glycine Max L.) rotation under conventional tillage; T5 - rice, soybean and corn (Zea maize L.) rotation under conventional tillage; T6 - rice under no-tillage in the summer in succession to rye-grass (Lolium multiflorum L.) in the winter; T7 - rice under no-tillage and soybean under conventional tillage rotation; T8 - control: uncultivated soil). The Gamma Ray Computed Tomography method did not identify compacted soil layers under no tillage rice in succession to rye-grass; two fallow years in the irrigated rice production system did not prevent the formation of a compacted layer at the soil surface; and in the rice, soybean and corn rotation under conventional tillage two compacted layers were identified (0.0 to 1.5 cm and 11 to 14 cm), indicating that they may restrict the agricultural production in this cultivation system on Albaqualf soils. (author)

  6. Identification of an industrial microalgal strain for starch production in biorefinery context

    NARCIS (Netherlands)

    Gifuni, Imma; Olivieri, Giuseppe; Pollio, Antonino; Marzocchella, Antonio

    2018-01-01

    The recent trends in microalgal cultures are focused on the biorefinery of the biomass components. Some of them are not completely valorised, for example starch. Since there is a wide market for starch products in food and non-food industries, the exploitation of microalgal starch fractions could

  7. An integrated ecosystem approach for assessing the potential role of cultivated bivalve shells as part of the carbon trading system

    DEFF Research Database (Denmark)

    Filgueira, Ramón; Byron, C.J.; Comeau, L.A.

    2015-01-01

    , is needed to provide a rigorous assessment of the role of bivalve mariculture in the CO2 cycle. On the other hand, the discussion about the inclusion of shells of cultured bivalves into the carbon trading system should be framed in the context of ecosystem goods and services. Humans culture bivalves......The role of bivalve mariculture in the CO2 cycle has been commonly evaluated as the balance between respiration, shell calcium carbonate sequestration and CO2 release during biogenic calcification. However, this approach neglects the ecosystem implications of cultivating bivalves at high densities...... with the aim of producing food, not sequestering CO2 in their shells, therefore the main ecosystem good provided by bivalve aquaculture is meat production, and shells should be considered as by-products of this human activity. This reasoning is key to split the CO2 released due to respiration between meat...

  8. Microbial quality and molecular identification of cultivable microorganisms isolated from an urban drinking water distribution system (Limassol, Cyprus).

    Science.gov (United States)

    Botsaris, George; Kanetis, Loukas; Slaný, Michal; Parpouna, Christiana; Makris, Konstantinos C

    2015-12-01

    Microorganisms can survive and multiply in aged urban drinking water distribution systems, leading to potential health risks. The objective of this work was to investigate the microbial quality of tap water and molecularly identify its predominant cultivable microorganisms. Tap water samples collected from 24 different households scattered in the urban area of Limassol, Cyprus, were microbiologically tested following standard protocols for coliforms, E. coli, Pseudomonas spp., Enterococcus spp., and total viable count at 22 and 37 °C. Molecular identification was performed on isolated predominant single colonies using 16SrRNA sequencing. Approximately 85% of the household water samples were contaminated with one or more microorganisms belonging to the genera of Pseudomonas, Corynebacterium, Agrobacterium, Staphylococcus, Bacillus, Delftia, Acinetobacter, Enterococcus, Enterobacter, and Aeromonas. However, all samples tested were free from E. coli. This is the first report in Cyprus molecularly confirming specific genera of relevant microbial communities in tap water.

  9. Indigenous systems of forest classification: understanding land use patterns and the role of NTFPs in shifting cultivators' subsistence economies.

    Science.gov (United States)

    Delang, Claudio O

    2006-04-01

    This article discusses the system of classification of forest types used by the Pwo Karen in Thung Yai Naresuan Wildlife Sanctuary in western Thailand and the role of nontimber forest products (NTFPs), focusing on wild food plants, in Karen livelihoods. The article argues that the Pwo Karen have two methods of forest classification, closely related to their swidden farming practices. The first is used for forest land that has been, or can be, swiddened, and classifies forest types according to growth conditions. The second system is used for land that is not suitable for cultivation and looks at soil properties and slope. The article estimates the relative importance of each forest type in what concerns the collection of wild food plants. A total of 134 wild food plant species were recorded in December 2004. They account for some 80-90% of the amount of edible plants consumed by the Pwo Karen, and have a base value of Baht 11,505 per year, comparable to the cash incomes of many households. The article argues that the Pwo Karen reliance on NTFPs has influenced their land-use and forest management practices. However, by restricting the length of the fallow period, the Thai government has caused ecological changes that are challenging the ability of the Karen to remain subsistence oriented. By ignoring shifting cultivators' dependence on such products, the involvement of governments in forest management, especially through restrictions imposed on swidden farming practices, is likely to have a considerable impact on the livelihood strategies of these communities.

  10. Reduction of environmental and energy footprint of microalgal biodiesel production through material and energy integration.

    Science.gov (United States)

    Chowdhury, Raja; Viamajala, Sridhar; Gerlach, Robin

    2012-03-01

    The life cycle impacts were assessed for an integrated microalgal biodiesel production system that facilitates energy- and nutrient- recovery through anaerobic digestion, and utilizes glycerol generated within the facility for additional heterotrophic biodiesel production. Results show that when external fossil energy inputs are lowered through process integration, the energy demand, global warming potential (GWP), and process water demand decrease significantly and become less sensitive to algal lipid content. When substitution allocation is used to assign additional credit for avoidance of fossil energy use (through utilization of recycled nutrients and biogas), GWP and water demand can, in fact, increase with increase in lipid content. Relative to stand-alone algal biofuel facilities, energy demand can be lowered by 3-14 GJ per ton of biodiesel through process integration. GWP of biodiesel from the integrated system can be lowered by up to 71% compared to petroleum fuel. Evaporative water loss was the primary water demand driver. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Deepen the Teaching Reform of Operating System, Cultivate the Comprehensive Quality of Students

    Science.gov (United States)

    Liu, Jianjun

    2010-01-01

    Operating system is the core course of the specialty of computer science and technology. To understand and master the operating system will directly affect students' further study on other courses. The course of operating system focuses more on theories. Its contents are more abstract and the knowledge system is more complicated. Therefore,…

  12. Scale-down of continuous protein producing Saccharomyces cerevisiae cultivations using a two compartment system

    DEFF Research Database (Denmark)

    Wright, Naia Risager; Rønnest, Nanna Petersen; Thykær, Jette

    2016-01-01

    ml standard continuous cultivations. It was found that substrate gradients within a limited range result in increased productivity of the heterologous protein under regulation of the glycolytic TPI promoter and delay the decrease of protein and trehalose production during continuous cultivation...

  13. Climate Management System for mushroom cultivation (CMMC). First phase. Inventory and functional design; Klimaat Managementsysteem Champignonteelt (KMC). 1e fase. Inventarisatie en functioneel ontwerp

    Energy Technology Data Exchange (ETDEWEB)

    Gielen, J.H. [DLV Plant, Horst (Netherlands)

    2011-03-15

    This report describes the feasibility and the opportunities of developing a Climate Management System for Mushroom Cultivation (CMMC) software package, based on which a decision can be made to proceed with the realization of phase 2 of the project, i.e. the actual construction of the CMMC for mushroom cultivation [Dutch] Deze rapportage beschrijft de haalbaarheid en de mogelijkheden van de ontwikkeling van een KMC software pakket, op basis waarvan besloten kan worden tot de realisatie van fase 2 van het project, de daadwerkelijke bouw van de KMC voor de champignonteelt.

  14. Studies on the effects on growth and antioxidant responses of two marine microalgal species to uniconazole

    Science.gov (United States)

    Mei, Xueqiao; Zheng, Kang; Wang, Lingdong; Li, Yantuan

    2014-10-01

    Uniconazole, as a plant growth retardant, can enhance stress tolerance in plants, possibly because of improved antioxidation defense mechanisms with higher activities of superoxide dismutase (SOD) and peroxidase (POD) enzymes that retard lipid peroxidation and membrane deterioration. These years much attention has been focused on the responses of antioxidant system in plants to uniconazole stress, but such studies on aquatic organism are very few. Moreover, no information is available on growth and antioxidant response in marine microalgae to uniconazole. In this paper, the growth and antioxidant responses of two marine microalgal species, Platymonas helgolandica and Pavlova viridis, at six uniconazole concentrations (0-15 mg L-1) were investigated. The results demonstrated that 3 mg L-1 uniconazole could increase significantly chlorophyll a and carbohydrate contents of P. helgolandica ( P enzymes, superoxide dismutase (SOD) and catalase (CAT) were enhanced remarkably at low concentrations of uniconazole. However, significant reduction of SOD and CAT activities was observed at higher concentrations of uniconazole.

  15. [Trends of microalgal biotechnology: a view from bibliometrics].

    Science.gov (United States)

    Yang, Xiaoqiu; Wu, Yinsong; Yan, Jinding; Song, Haigang; Fan, Jianhua; Li, Yuanguang

    2015-10-01

    Microalgae is a single-cell organism with the characteristics of high light energy utilization rate, fast growth rate, high-value bioactive components and high energy material content. Therefore, microalgae has broad application prospects in food, feed, bioenergy, carbon sequestration, wastewater treatment and other fields. In this article, the microalgae biotechnology development in recent years were fully consulted, through analysis from the literature and patent. The progress of microalgal biotechnology at home and abroad is compared and discussed. Furthermore, the project layout, important achievements and development bottlenecks of microalgae biotechnology in our country were also summarized. At last, future development directions of microalgae biotechnology were discussed.

  16. Cultivating User-ship? Developing a Circular System for the Acquisition and Use of Baby Clothing

    DEFF Research Database (Denmark)

    Petersen, Trine Brun; Riisberg, Vibeke

    2017-01-01

    This paper sets out to explore the significance of the production, sale and consumption of clothing as a product service system rather than as the more familiar “shop-window” product offered for individual sale. While there are a number of studies of occupational clothing systems, relatively little...... is known about clothing systems tailored for the private market. This article presents a case study of a recently launched subscription service for baby clothing, which offered a range of eco-certified garments for rent as more or less complete wardrobes. Drawing on fashion scholar Kate Fletcher’s concept...... features are mutually constitutive and to how the system interconnects with practices of use and maintenance among subscribers with a special interest in laundry regimes and durability. Taking this empirical example as its point of departure, the article concludes with a discussion of how product qualities...

  17. Vegetable Cultivation Hydroponics System In Community Economic Zone KEM Kanagarian Tikalak Subdistrict X Koto Singkarak Districts Solok

    Directory of Open Access Journals (Sweden)

    I Ketut Budaraga

    2017-05-01

    Full Text Available Current conditions especially in urban agricultural land is getting narrower due to the rapid development. If left untreated it can lead to food security and environmental problems. One solution to allow the fulfillment of foodstuffs such as vegetables can be fulfilled for the people to exploit the potential of the narrow yard with continuous production of hydroponic systems. Interest dedication to the community to find ways to introduce a hydroponic vegetable crops that can supplement the family income of farmers. Benefits of the service is expected to increase peoples income and the public generally in Community Economic Zone KEM Kanagarian Tikalak in particular and can provide lucrative benefits for the environment. Devotion execution method implemented by a lecture and demonstration. The materials used such as husks seeds of vegetables kale collards caisin hydroponic media such as slug biogas rope bamboo to place the plants grow. The results of this activity the community has been able to make a hydroponic vegetable cultivation system and has been applied to plant vegetables such as kale collards and caisin.

  18. Influence of genotype, cultivation system and irrigation regime on antioxidant capacity and selected phenolics of blueberries (Vaccinium corymbosum L.).

    Science.gov (United States)

    Cardeñosa, Vanessa; Girones-Vilaplana, Amadeo; Muriel, José Luis; Moreno, Diego A; Moreno-Rojas, José M

    2016-07-01

    Demand for and availability of blueberries has increased substantially over recent years, driven in part by their health-promoting properties. Three blueberry varieties ('Rocío', V2, and V3) were grown under two cultivation systems (open-field and plastic tunnels) and subjected to two irrigations regimes (100% and 80% of crop evapotranspiration) in two consecutive years (2011-2012). They were evaluated for their phytochemical composition and antioxidant capacity. Genotype influenced the antioxidant capacity and the content of the three groups of phenolics in the blueberries. The antioxidant activity and total flavonols content increased when the blueberries were grown under open-field conditions. Deficit irrigation conditions led to additional positive effects on their phenolics (delphinidn-3-acetilhexoside content was increased under plastic tunnel with deficit irrigation). In conclusion, the amount of phenolic compounds and the antioxidant capacity of blueberries were not negatively affected by water restriction; Moreover, several changes were recorded due to growing system and genotype. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Elimination of root-infecting pathogens in recirculation water from closed cultivation systems by ultra-violet radiation

    International Nuclear Information System (INIS)

    Runia, W.T.

    1994-01-01

    The development from growing in border soil to soilless cultures has not resulted in the disappearance of soil-borne diseases. Most root-infecting pathogens also occur in these new cultivation systems. Some pathogens such as Pythium, Phytophthora, cucumber green mottle mosaic virus and tomato mosaic virus are easily transmitted in recirculation water as is Olpidium, the vector of several viruses. To exclude any risk of dispersal of plant pathogens the water has to be sterilised before re-use. Rainwater collected from the glasshouse roof can also be contaminated with pathogens. When this rainwater is used for irrigation water it should be disinfected first. Currently water disinfection by heating or ozonisation is applied on some 450 nurseries. Initially ultra-violet(UV) radiation was not effective against plant pathogens. Only at a low capacity of 18 l h -1 and a high UV-dose of 430 mJ cm -2 could fungal spores be eliminated in nutrient solution. A low capacity however implies a poor turbulence in the water, resulting in varying UV-doses in the different water layers. Two new UV-installations with high capacities were tested for their efficacy against fungal and viral plant pathogens. One installation was equipped with a high-pressure and the other with a low-pressure mercury vapour lamp. In both installations a sandfilter first removed organic particles from the water. A UV-dose from the high-pressure lamp of 28 mJ cm -2 reduced the infectivity of conidia of Fusarium oxysporum f.sp lycopersici by 90 % resulting in a 99.9 % reduction at 84 mJ cm -2 . The low-pressure lamp completely eliminated conidia of Fusarium at a UV-dose of 70 mJ cm -2 . Tomato mosaic virus was reduced by 99 % using a UV-dose of 100 mJ cm -2 in both installations. Ultra-violet radiation can be effective against plant pathogens providing the dose under controlled conditions is sufficient. Numerous growers use UV-radiation for the disinfection of water in closed cultivation systems. (author)

  20. Automation of a Nile red staining assay enables high throughput quantification of microalgal lipid production.

    Science.gov (United States)

    Morschett, Holger; Wiechert, Wolfgang; Oldiges, Marco

    2016-02-09

    Within the context of microalgal lipid production for biofuels and bulk chemical applications, specialized higher throughput devices for small scale parallelized cultivation are expected to boost the time efficiency of phototrophic bioprocess development. However, the increasing number of possible experiments is directly coupled to the demand for lipid quantification protocols that enable reliably measuring large sets of samples within short time and that can deal with the reduced sample volume typically generated at screening scale. To meet these demands, a dye based assay was established using a liquid handling robot to provide reproducible high throughput quantification of lipids with minimized hands-on-time. Lipid production was monitored using the fluorescent dye Nile red with dimethyl sulfoxide as solvent facilitating dye permeation. The staining kinetics of cells at different concentrations and physiological states were investigated to successfully down-scale the assay to 96 well microtiter plates. Gravimetric calibration against a well-established extractive protocol enabled absolute quantification of intracellular lipids improving precision from ±8 to ±2 % on average. Implementation into an automated liquid handling platform allows for measuring up to 48 samples within 6.5 h, reducing hands-on-time to a third compared to manual operation. Moreover, it was shown that automation enhances accuracy and precision compared to manual preparation. It was revealed that established protocols relying on optical density or cell number for biomass adjustion prior to staining may suffer from errors due to significant changes of the cells' optical and physiological properties during cultivation. Alternatively, the biovolume was used as a measure for biomass concentration so that errors from morphological changes can be excluded. The newly established assay proved to be applicable for absolute quantification of algal lipids avoiding limitations of currently established

  1. Assessment of multifunctional bio fertilizers on tomato plants cultivated under a fertigation system

    International Nuclear Information System (INIS)

    Phua Choo Kwai Hoe; Ahmad Nazrul Abdul Wahid; Khairuddin Abdul Rahim

    2012-01-01

    Malaysian Nuclear Agency (Nuclear Malaysia) has developed a series of multifunctional bio organic fertilizers, namely, MULTIFUNCTIONAL BIOFERT PG and PA and MF-BIOPELLET, in an effort to reduce dependency on chemical fertilizer for crop production. These products contain indigenous microorganisms that have desired characteristics, which include plant growth promoting, phosphate solubilising, antagonistic towards bacterial wilt disease and enhancing N 2 -fixing activity. These products were formulated as liquid inoculants, and introduced into a fertigation system in an effort to reduce usage of chemical fertilizers. A greenhouse trial was conducted to evaluate the effectiveness of multifunctional bio fertilizers on tomato plants grown under a fertigation system. Multifunctional bio fertilizer products were applied singly and in combination with different rates of NPK in the fertigation system. Fresh and dry weights of tomato plants were determined. Application of multifunctional bio fertilizer combined with 20 g NPK resulted in significantly higher fresh and dry weights as compared to other treatments. (author)

  2. Light requirements in microalgal photobioreactors. An overview of biophotonic aspects

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Ana P. [Universidade Catolica Portuguesa, Porto (Portugal). CBQF/Escola Superior de Biotecnologia; Silva, Susana O. [Universidade Catolica Portuguesa, Porto (Portugal). CBQF/Escola Superior de Biotecnologia; INESC Porto, Porto (Portugal); Baptista, Jose M. [INESC Porto, Porto (Portugal); Universidade da Madeira, Funchal (Portugal). Centro de Competencia de Ciencias Exactas e de Engenharia; Malcata, F. Xavier [ISMAI - Instituto Superior da Maia, Avioso S. Pedro (Portugal); Universidade Nova de Lisboa, Oeiras (Portugal). Inst. de Tecnologia Quimica e Biologica

    2011-03-15

    In order to enhance microalgal growth in photobioreactors (PBRs), light requirement is one of the most important parameters to be addressed; light should indeed be provided at the appropriate intensity, duration, and wavelength. Excessive intensity may lead to photo-oxidation and -inhibition, whereas low light levels will become growth-limiting. The constraint of light saturation may be overcome via either of two approaches: increasing photosynthetic efficiency by genetic engineering, aimed at changing the chlorophyll antenna size; or increasing flux tolerance, via tailoring the photonic spectrum, coupled with its intensity and temporal characteristics. These approaches will allow an increased control over the illumination features, leading to maximization of microalgal biomass and metabolite productivity. This minireview briefly introduces the nature of light, and describes its harvesting and transformation by microalgae, as well as its metabolic effects under excessively low or high supply. Optimization of the photosynthetic efficiency is discussed under the two approaches referred to above; the selection of light sources, coupled with recent improvements in light handling by PBRs, are chronologically reviewed and critically compared. (orig.)

  3. Thermochemical conversion of microalgal biomass into biofuels: a review.

    Science.gov (United States)

    Chen, Wei-Hsin; Lin, Bo-Jhih; Huang, Ming-Yueh; Chang, Jo-Shu

    2015-05-01

    Following first-generation and second-generation biofuels produced from food and non-food crops, respectively, algal biomass has become an important feedstock for the production of third-generation biofuels. Microalgal biomass is characterized by rapid growth and high carbon fixing efficiency when they grow. On account of potential of mass production and greenhouse gas uptake, microalgae are promising feedstocks for biofuels development. Thermochemical conversion is an effective process for biofuel production from biomass. The technology mainly includes torrefaction, liquefaction, pyrolysis, and gasification. Through these conversion technologies, solid, liquid, and gaseous biofuels are produced from microalgae for heat and power generation. The liquid bio-oils can further be upgraded for chemicals, while the synthesis gas can be synthesized into liquid fuels. This paper aims to provide a state-of-the-art review of the thermochemical conversion technologies of microalgal biomass into fuels. Detailed conversion processes and their outcome are also addressed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Microalgal biomass pretreatment for bioethanol production: a review

    Directory of Open Access Journals (Sweden)

    Jesús Velazquez-Lucio

    2018-03-01

    Full Text Available Biofuels derived from microalgae biomass have received a great deal of attention owing to their high potentials as sustainable alternatives to fossil fuels. Microalgae have a high capacity of CO2 fixation and depending on their growth conditions, they can accumulate different quantities of lipids, proteins, and carbohydrates. Microalgal biomass can, therefore, represent a rich source of fermentable sugars for third generation bioethanol production. The utilization of microalgal carbohydrates for bioethanol production follows three main stages: i pretreatment, ii saccharification, and iii fermentation. One of the most important stages is the pretreatment, which is carried out to increase the accessibility to intracellular sugars, and thus plays an important role in improving the overall efficiency of the bioethanol production process. Diverse types of pretreatments are currently used including chemical, thermal, mechanical, biological, and their combinations, which can promote cell disruption, facilitate extraction, and result in the modification the structure of carbohydrates as well as the production of fermentable sugars. In this review, the different pretreatments used on microalgae biomass for bioethanol production are presented and discussed. Moreover, the methods used for starch and total carbohydrates quantification in microalgae biomass are also briefly presented and compared.

  5. Applications of Microalgal Biotechnology for Disease Control in Aquaculture

    Directory of Open Access Journals (Sweden)

    Patai Charoonnart

    2018-04-01

    Full Text Available Aquaculture industries, and in particular the farming of fish and crustaceans, are major contributors to the economy of many countries and an increasingly important component in global food supply. However, the severe impact of aquatic microbial diseases on production performance remains a challenge to these industries. This article considers the potential applications of microalgal technology in the control of such diseases. At the simplest level, microalgae offer health-promoting benefits as a nutritional supplement in feed meal because of their digestibility and high content of proteins, lipids and essential nutrients. Furthermore, some microalgal species possess natural anti-microbial compounds or contain biomolecules that can serve as immunostimulants. In addition, emerging genetic engineering technologies in microalgae offer the possibility of producing ‘functional feed additives’ in which novel and specific bioactives, such as fish growth hormones, anti-bacterials, subunit vaccines, and virus-targeted interfering RNAs, are components of the algal supplement. The evaluation of such technologies for farm applications is an important step in the future development of sustainable aquaculture.

  6. Adsorptive removal of cesium using bio fuel extraction microalgal waste

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Katsutoshi, E-mail: inoue@elechem.chem.saga-u.ac.jp [Department of Applied Chemistry, Faculty of Science and Engineering, Saga University, Honjo 1, Saga 840-8502 (Japan); Gurung, Manju [Department of Applied Chemistry, Faculty of Science and Engineering, Saga University, Honjo 1, Saga 840-8502 (Japan); Faculty of Engineering and Applied Science, Memorial University of Newfoundland, St. John' s, NL, Canada A1B 3X5 (Canada); Adhikari, Birendra Babu; Alam, Shafiq [Faculty of Engineering and Applied Science, Memorial University of Newfoundland, St. John' s, NL, Canada A1B 3X5 (Canada); Kawakita, Hidetaka; Ohto, Keisuke [Department of Applied Chemistry, Faculty of Science and Engineering, Saga University, Honjo 1, Saga 840-8502 (Japan); Kurata, Minoru [Research Laboratories, DENSO CORPORATION, Minamiyama 500-1, Komenoki, Nisshin, Aichi 470-0111 (Japan); Atsumi, Kinya [New Business Promotion Dept., DENSO CORPORATION, Showa-cho 1-1, Kariya, Aichi 448-8661 (Japan)

    2014-04-01

    Highlights: • A novel biosorbent was prepared from the microalgal waste after biofuel extraction. • Higher selectivity and adsorption efficiency of the adsorbent for Cs{sup +} over Na{sup +} ions from aqueous solutions. • Potential candidate and eco-friendly alternative to the commercial resins such as zeolite. - Abstract: An adsorption gel was prepared from microalgal waste after extracting biodiesel oil by a simple chemical treatment of crosslinking using concentrated sulfuric acid. The adsorbent exhibited notably high selectivity and adsorption capacity towards Cs{sup +} over Na{sup +} from aqueous solutions, within the pH range of slightly acidic to neutral. The adsorption followed Langmuir isotherm and the maximum adsorption capacity of the gel for Cs{sup +} calculated from Langmuir model was found to be 1.36 mol kg{sup −1}. Trace concentration of Cs{sup +} ions present in aqueous streams was successfully separated from Na{sup +} ions using a column packed with the adsorbent at pH 6.5. The adsorption capacity of the gel towards Cs{sup +} in column operation was 0.13 mol kg{sup −1}. Although the adsorbed Cs{sup +} ions were easily eluted using 1 M hydrochloric acid solution, simple incineration is proposed as an alternative for the treatment of adsorbent loaded with radioactive Cs{sup +} ions due to the combustible characteristics of this adsorbent.

  7. Agroforestry systems, nutrients in litter and microbial activity in soils cultivated with coffee at high altitude

    Directory of Open Access Journals (Sweden)

    Krystal de Alcantara Notaro

    2014-04-01

    Full Text Available Agroforestry systems are an alternative option for sustainable production management. These systems contain trees that absorb nutrients from deeper layers of the soil and leaf litter that help improve the soil quality of the rough terrain in high altitude areas, which are areas extremely susceptible to environmental degradation. The aim of this study was to characterize the stock and nutrients in litter, soil activity and the population of microorganisms in coffee (Coffea arabica L. plantations under high altitude agroforestry systems in the semi-arid region of the state of Pernambuco, Brazil. Samples were collected from the surface litter together with soil samples taken at two depths (0-10 and 10-20 cm from areas each subject to one of the following four treatments: agroforestry system (AS, native forest (NF, biodynamic system (BS and coffee control (CT.The coffee plantation had been abandoned for nearly 15 years and, although there had been no management or harvesting, still contained productive coffee plants. The accumulation of litter and mean nutrient content of the litter, the soil nutrient content, microbial biomass carbon, total carbon, total nitrogen, C/N ratio, basal respiration, microbial quotient, metabolic quotient and microbial populations (total bacteria, fluorescent bacteria group, total fungi and Trichoderma spp. were all analyzed. The systems thatwere exposed to human intervention (A and BS differed in their chemical attributes and contained higher levels of nutrients when compared to NF and CT. BS for coffee production at high altitude can be used as a sustainable alternative in the high altitude zones of the semi-arid region in Brazil, which is an area that is highly susceptible to environmental degradation.

  8. Microbiological and faunal soil attributes of coffee cultivation under different management systems in Brazil

    Directory of Open Access Journals (Sweden)

    D. R. Lammel

    Full Text Available Abstract Brazil is the biggest coffee producer in the world and different plantation management systems have been applied to improve sustainability and soil quality. Little is known about the environmental effects of these different management systems, therefore, the goal of this study was to use soil biological parameters as indicators of changes. Soils from plantations in Southeastern Brazil with conventional (CC, organic (OC and integrated management systems containing intercropping of Brachiaria decumbens (IB or Arachis pintoi (IA were sampled. Total organic carbon (TOC, microbial biomass carbon (MBC and nitrogen (MBN, microbial activity (C-CO2, metabolic quotient (qCO2, the enzymes dehydrogenase, urease, acid phosphatase and arylsulphatase, arbuscular mycorrhizal fungi (AMF colonization and number of spores and soil fauna were evaluated. The greatest difference between the management systems was seen in soil organic matter content. The largest quantity of TOC was found in the OC, and the smallest was found in IA. TOC content influenced soil biological parameters. The use of all combined attributes was necessary to distinguish the four systems. Each management presented distinct faunal structure, and the data obtained with the trap method was more reliable than the TSBF (Tropical Soils method. A canonic correlation analysis showed that Isopoda was correlated with TOC and the most abundant order with OC. Isoptera was the most abundant faunal order in IA and correlated with MBC. Overall, OC had higher values for most of the biological measurements and higher populations of Oligochaeta and Isopoda, corroborating with the concept that the OC is a more sustainable system.

  9. Microbiological and faunal soil attributes of coffee cultivation under different management systems in Brazil.

    Science.gov (United States)

    Lammel, D R; Azevedo, L C B; Paula, A M; Armas, R D; Baretta, D; Cardoso, E J B N

    2015-11-01

    Brazil is the biggest coffee producer in the world and different plantation management systems have been applied to improve sustainability and soil quality. Little is known about the environmental effects of these different management systems, therefore, the goal of this study was to use soil biological parameters as indicators of changes. Soils from plantations in Southeastern Brazil with conventional (CC), organic (OC) and integrated management systems containing intercropping of Brachiaria decumbens (IB) or Arachis pintoi (IA) were sampled. Total organic carbon (TOC), microbial biomass carbon (MBC) and nitrogen (MBN), microbial activity (C-CO2), metabolic quotient (qCO2), the enzymes dehydrogenase, urease, acid phosphatase and arylsulphatase, arbuscular mycorrhizal fungi (AMF) colonization and number of spores and soil fauna were evaluated. The greatest difference between the management systems was seen in soil organic matter content. The largest quantity of TOC was found in the OC, and the smallest was found in IA. TOC content influenced soil biological parameters. The use of all combined attributes was necessary to distinguish the four systems. Each management presented distinct faunal structure, and the data obtained with the trap method was more reliable than the TSBF (Tropical Soils) method. A canonic correlation analysis showed that Isopoda was correlated with TOC and the most abundant order with OC. Isoptera was the most abundant faunal order in IA and correlated with MBC. Overall, OC had higher values for most of the biological measurements and higher populations of Oligochaeta and Isopoda, corroborating with the concept that the OC is a more sustainable system.

  10. Cultivating Undergraduates' Plagiarism Avoidance Knowledge and Skills with an Online Tutorial System

    Science.gov (United States)

    Liu, Gi-Zen; Lu, Hui-Ching; Lin, Vivien; Hsu, Wei-Chen

    2018-01-01

    With the increased use of digital materials, undergraduate writers in English as a foreign language (EFL) contexts have become more susceptible to plagiarism. In this study, the researchers designed a blended English writing course with an online writing tutorial system entitled "DWright." The study examined the effectiveness of the…

  11. Cs phytoremediation by Sorghum bicolor cultivated in soil and in hydroponic system.

    Science.gov (United States)

    Wang, Xu; Chen, Can; Wang, Jianlong

    2017-04-03

    Cs accumulation characteristics by Sorghum bicolor were investigated in hydroponic system (Cs level at 50-1000 μmol/L) and in soil (Cs-spiked concentration was 100 and 400 mg/kg soil). Two varieties of S. bicolor Cowly and Nengsi 2# grown on pot soil during the entire growth period (100 days) did not show significant differences on the height, dry weight (DW), and Cs accumulation. S. bicolor showed the potential phytoextraction ability for Cs-contaminated soil with the bioaccumulation factor (BCF) and the translocation factor (TF) values usually higher than 1 in soil system and in hydroponic system. The aerial parts of S. bicolor contributed to 86-92% of the total removed amounts of Cs from soil. Cs level in solution at 100 μmol/L gave the highest BCF and TF values of S. bicolor. Cs at low level tended to transfer to the aerial parts, whereas Cs at high level decreased the transfer ratio from root to shoot. In soil, the plant grew well when Cs spiked level was 100 mg/kg soil, but was inhibited by Cs at 400 mg/kg soil with Cs content in sorghum reaching 1147 mg/kg (roots), 2473 mg/kg (stems), and 2939 mg/kg (leaves). In hydroponic system, average Cs level in sorghum reached 5270 mg/kg (roots) and 4513 mg/kg (aerial parts), without significant damages to its biomass at 30 days after starting Cs treatment. Cs accumulation in sorghum tissues was positively correlated with the metal concentration in medium.

  12. Soil physical and microbiological attributes cultivated with the common bean under two management systems

    Directory of Open Access Journals (Sweden)

    Lorena Adriana De Gennaro

    Full Text Available Agricultural management systems can alter the physical and biological soil quality, interfering with crop development. The objective of this study was to evaluate the physical and microbiological attributes of a Red Latosol, and its relationship to the biometric parameters of the common bean (Phaseolus vulgaris, irrigated and grown under two management systems (conventional tillage and direct seeding, in Campinas in the state of São Paulo, Brazil. The experimental design was of randomised blocks, with a split-plot arrangement for the management system and soil depth, analysed during the 2006/7 and 2007/8 harvest seasons, with 4 replications. The soil physical and microbiological attributes were evaluated at depths of 0.00-0.05, 0.05-0.10, 0.10-0.20 and 0.20-0.40 m. The following were determined for the crop: density, number of pods per plant, number of beans per pod, thousand seed weight, total weight of the shoots and harvest index. Direct seeding resulted in a lower soil physical quality at a depth of 0.00-0.05 m compared to conventional tillage, while the opposite occurred at a depth of 0.05-0.10 m. The direct seeding showed higher soil biological quality, mainly indicated by the microbial biomass nitrogen, basal respiration and metabolic quotient. The biometric parameters in the bean were higher under the direct seeding compared to conventional tillage.

  13. Microalgal technology for remediation of CO{sub 2} from power plant flue gas: A technoeconomic perspective

    Energy Technology Data Exchange (ETDEWEB)

    Kadam, K.L.; Sheehan, J.J. [National Renewable Energy Lab., Golden, CO (United States). Biotechnology Center for Fuels and Chemicals

    1996-12-01

    Power plants burning fossil fuels are a major source of CO{sub 2}, which is implicated in global warming. Microalgal systems, which photosynthetically assimilate CO{sub 2}, can be used to mitigate this major greenhouse gas. A technoeconomic model was developed for trapping CO{sub 2} from flue gases by microalgae in outdoor ponds. The model allows the authors to make some notable observations about the microalgal process. For example, although it was known that the delivered CO{sub 2} cost is an important parameter, this model demonstrates in quantitative terms that the targeted improvements for productivity and lipid content double the relative impact of CO{sub 2} resource cost on total annualized cost of the technology. The model also shows that both algal lipid content and growth rate are important for an economical process, but a trade-off exists between the two, i.e., a high lipid content and low growth rate combination can be as effective as a low lipid content and high growth rate combination. Model predictions were also used to compare the microalgal technology with alternative technologies in terms of CO{sub 2} mitigation costs. The mid-term process, which can be implemented in the near future, is competitive with other CO{sub 2} remediation technologies currently being proposed. Incorporating anticipated advances into the design basis, a CO{sub 2} mitigation cost of $30/t (CO{sub 2} avoided basis) is obtained for the long-term process, which is very promising. Deployment of this technology for CO{sub 2} mitigation looks attractive if research goals put forth by the model are achieved.

  14. Exploration of plant growth and development using the European Modular Cultivation System facility on the International Space Station.

    Science.gov (United States)

    Kittang, A-I; Iversen, T-H; Fossum, K R; Mazars, C; Carnero-Diaz, E; Boucheron-Dubuisson, E; Le Disquet, I; Legué, V; Herranz, R; Pereda-Loth, V; Medina, F J

    2014-05-01

    Space experiments provide a unique opportunity to advance our knowledge of how plants respond to the space environment, and specifically to the absence of gravity. The European Modular Cultivation System (EMCS) has been designed as a dedicated facility to improve and standardise plant growth in the International Space Station (ISS). The EMCS is equipped with two centrifuges to perform experiments in microgravity and with variable gravity levels up to 2.0 g. Seven experiments have been performed since the EMCS was operational on the ISS. The objectives of these experiments aimed to elucidate phototropic responses (experiments TROPI-1 and -2), root gravitropic sensing (GRAVI-1), circumnutation (MULTIGEN-1), cell wall dynamics and gravity resistance (Cell wall/Resist wall), proteomic identification of signalling players (GENARA-A) and mechanism of InsP3 signalling (Plant signalling). The role of light in cell proliferation and plant development in the absence of gravity is being analysed in an on-going experiment (Seedling growth). Based on the lessons learned from the acquired experience, three preselected ISS experiments have been merged and implemented as a single project (Plant development) to study early phases of seedling development. A Topical Team initiated by European Space Agency (ESA), involving experienced scientists on Arabidopsis space research experiments, aims at establishing a coordinated, long-term scientific strategy to understand the role of gravity in Arabidopsis growth and development using already existing or planned new hardware. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  15. Land-use poverty traps identified in shifting cultivation systems shape long-term tropical forest cover

    Science.gov (United States)

    Coomes, Oliver T.; Takasaki, Yoshito; Rhemtulla, Jeanine M.

    2011-01-01

    In this article we illustrate how fine-grained longitudinal analyses of land holding and land use among forest peasant households in an Amazonian village can enrich our understanding of the poverty/land cover nexus. We examine the dynamic links in shifting cultivation systems among asset poverty, land use, and land cover in a community where poverty is persistent and primary forests have been replaced over time—with community enclosure—by secondary forests (i.e., fallows), orchards, and crop land. Land cover change is assessed using aerial photographs/satellite imagery from 1965 to 2007. Household and plot level data are used to track land holding, portfolios, and use as well as land cover over the past 30 y, with particular attention to forest status (type and age). Our analyses find evidence for two important types of “land-use” poverty traps—a “subsistence crop” trap and a “short fallow” trap—and indicate that the initial conditions of land holding by forest peasants have long-term effects on future forest cover and household welfare. These findings suggest a new mechanism driving poverty traps: insufficient initial land holdings induce land use patterns that trap households in low agricultural productivity. Path dependency in the evolution of household land portfolios and land use strategies strongly influences not only the wellbeing of forest people but also the dynamics of tropical deforestation and secondary forest regrowth. PMID:21873179

  16. Cut and carry vs. grazing of cultivated pastures in small-scale dairy systems in the central highlands of Mexico

    Directory of Open Access Journals (Sweden)

    Paola Estefania Pincay-Figueroa

    2016-12-01

    Full Text Available Small-scale dairy systems are an option to alleviate poverty and contribute up to 37% of milk production in Mexico; however high costs affect their economic sustainability. Since grazing may reduce feeding costs, a participatory on farm experiment was undertaken to compare animal performance and feeding costs of the traditional cut-and-carry strategy or grazing cultivated pastures, during the dry season in the highlands of Mexico. Pastures of perennial and annual ryegrasses with white clover were utilised, complemented with maize silage and commercial concentrate. Five dairy cows were assigned to each strategy. The experiment ran for 12 weeks, recording weekly milk yields and fat and milk protein content; live-weight and body condition score every 14 days. Analysis was as a split-plot design. The adjusted (covariance mean milk yield was 18.78 kg/cow/day with no significant differences (P>0.05 between treatments, and no significant differences for live-weight or body condition score. There were no significant differences for milk fat (P>0.05, but there were for protein in milk (P

  17. SYSTEM DYNAMIC MODELLING AND SIMULATION FOR CULTIVATION OF FOREST LAND: CASE STUDY PERUM PERHUTANI, CENTRAL JAVA, INDONESIA

    Directory of Open Access Journals (Sweden)

    Candra Musi

    2017-07-01

    Full Text Available The deforestation and forest degradation rates have a propensity to rise every year. The problems in pertaining with the issue is not solely preoccupied on the ecological concern but also to the socio-economic impacts. The complexity of forest management is a serious barrier in determining a better management policy. Modeling system is a simple method to describe the real situation in nature. A qualitative approach is used to identify the relationship between the dynamics of important behaviors. The causal relationships among the factors were investigated by using causal loop diagram. The model conceptualization was constructed by using a stock-flow diagram. The result of the simulation model was used to determine the alternative policies for better forest management. The results indicated that the tenant welfare would be enhanced through the provision of production-sharing by 25% and the Corporate Social Responsibility by 2%, which yields a reduction in cultivated area of ​​916.61 ha within a period of 67 years or a decline of land area by an average of 13.68 ha per year.

  18. Heavy metal dynamics in the soil-leaf-fruit system under intensive apple cultivation

    Directory of Open Access Journals (Sweden)

    Murtić Senad

    2014-01-01

    Full Text Available One of the major problems confronting agricultural production is heavy metal contamination of agricultural soils, which imposes considerable limitations on productivity and leads to great consumer health and safety concerns about the products obtained on these soils. The objective of this study was to evaluate heavy metal dynamics in the soil-leaf-fruit system in an intensive apple cv. 'Idared' planting located in the Municipality of Goražde. Heavy metal contents in the soil samples and plant material were determined by atomic absorption spectrophotometry using a Shimadzu 7000 AA device, according to the instructions specified in the ISO 11047 method. The dynamics of the heavy metals analyzed, excepting zinc, in the soil-leaf-fruit system was characterized by relatively high total levels of heavy metals in the soil and a very low degree of their accumulation in the leaves and in particular the fruits. No fruit sample was found to have toxic levels of any of the heavy metals analyzed. In terms of soil contamination, this suggests the suitability of the study location for safe apple fruit production.

  19. Reduction of soil erosion and mercury losses in agroforestry systems compared to forests and cultivated fields in the Brazilian Amazon.

    Science.gov (United States)

    Béliveau, Annie; Lucotte, Marc; Davidson, Robert; Paquet, Serge; Mertens, Frédéric; Passos, Carlos J; Romana, Christine A

    2017-12-01

    In addition to causing physical degradation and nutrient depletion, erosion of cultivated soils in the Amazon affects aquatic ecosystems through the release of natural soil mercury (Hg) towards lakes and rivers. While traditional agriculture is generally cited as being among the main causes of soil erosion, agroforestry practices are increasingly appreciated for soil conservation. This study was carried out in family farms of the rural Tapajós region (Brazil) and aimed at evaluating soil erosion and associated Hg release for three land uses. Soils, runoff water and eroded sediments were collected at three sites representing a land cover gradient: a recently burnt short-cycle cropping system (SCC), a 2-year-old agroforestry system (AFS) and a mature forest (F). At each site, two PVC soil erosion plots (each composed of three 2 × 5 m isolated subplots) were implemented on steep and moderate slopes respectively. Sampling was done after each of the 20 rain events that occurred during a 1-month study period, in the peak of the 2011 rain season. Runoff volume and rate, as well as eroded soil particles with their Hg and cation concentrations were determined. Total Hg and cation losses were then calculated for each subplot. Erosion processes were dominated by land use type over rainfall or soil slope. Eroded soil particles, as well as the amount of Hg and cations (CaMgK) mobilized at the AFS site were similar to those at the F site, but significantly lower than those at the SCC site (p agroforestry systems, even in their early stages of implementation, are characterized by low erosion levels resembling those of local forest environments, thus contributing to the maintenance of soil integrity and to the reduction of Hg and nutrient mobility. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. An Interactive Tool for Outdoor Computer Controlled Cultivation of Microalgae in a Tubular Photobioreactor System

    Directory of Open Access Journals (Sweden)

    Raquel Dormido

    2014-03-01

    Full Text Available This paper describes an interactive virtual laboratory for experimenting with an outdoor tubular photobioreactor (henceforth PBR for short. This virtual laboratory it makes possible to: (a accurately reproduce the structure of a real plant (the PBR designed and built by the Department of Chemical Engineering of the University of Almería, Spain; (b simulate a generic tubular PBR by changing the PBR geometry; (c simulate the effects of changing different operating parameters such as the conditions of the culture (pH, biomass concentration, dissolved O2, inyected CO2, etc.; (d simulate the PBR in its environmental context; it is possible to change the geographic location of the system or the solar irradiation profile; (e apply different control strategies to adjust different variables such as the CO2 injection, culture circulation rate or culture temperature in order to maximize the biomass production; (f simulate the harvesting. In this way, users can learn in an intuitive way how productivity is affected by any change in the design. It facilitates the learning of how to manipulate essential variables for microalgae growth to design an optimal PBR. The simulator has been developed with Easy Java Simulations, a freeware open-source tool developed in Java, specifically designed for the creation of interactive dynamic simulations.

  1. Tillage systems and cover crops on soil physical properties after soybean cultivation

    Directory of Open Access Journals (Sweden)

    Rafael B. Teixeira

    Full Text Available ABSTRACT Soil management alters soil physical attributes and may affect crop yield. In order to evaluate soil physical attributes in layers from 0 to 0.40 m and soybean grain yield, in the 2012/2013 agricultural year, an essay was installed in the experimental area of the Federal University of Mato Grosso do Sul (UFMS/CPCS. Soil tillage systems were: conventional tillage (CT, minimum tillage (MT and no tillage (DS, the cover crops used were millet, sunn hemp and fallow. The experimental design was randomized blocks with split plots. For the layer of 0.20-0.30 m, millet provided the best results for soil bulk density, macro and microporosity. The resistance to penetration (RP was influenced in the layer of 0-0.10 m, and millet provided lower RP. The DS provided the lowest RP values for the layer of 0.10-0.20 m. The treatments did not influence yield or thousand-seed weight.

  2. Cultivation of students' engineering designing ability based on optoelectronic system course project

    Science.gov (United States)

    Cao, Danhua; Wu, Yubin; Li, Jingping

    2017-08-01

    We carry out teaching based on optoelectronic related course group, aiming at junior students majored in Optoelectronic Information Science and Engineering. " Optoelectronic System Course Project " is product-designing-oriented and lasts for a whole semester. It provides a chance for students to experience the whole process of product designing, and improve their abilities to search literature, proof schemes, design and implement their schemes. In teaching process, each project topic is carefully selected and repeatedly refined to guarantee the projects with the knowledge integrity, engineering meanings and enjoyment. Moreover, we set up a top team with professional and experienced teachers, and build up learning community. Meanwhile, the communication between students and teachers as well as the interaction among students are taken seriously in order to improve their team-work ability and communicational skills. Therefore, students are not only able to have a chance to review the knowledge hierarchy of optics, electronics, and computer sciences, but also are able to improve their engineering mindset and innovation consciousness.

  3. Utilization of distillery stillage for energy generation and concurrent production of valuable microalgal biomass in the sequence: Biogas-cogeneration-microalgae-products

    Energy Technology Data Exchange (ETDEWEB)

    Douskova, Irena; Doucha, Jiri; Zachleder, Vilem [Laboratory of Cell Cycles of Algae, Department of Autotrophic Microorganisms, Institute of Microbiology of the Academy of Sciences of the Czech Republic, Novohradska 237, 379 81 Trebon - Opatovicky mlyn (Czech Republic); Kastanek, Frantisek; Maleterova, Ywette [Institute of Chemical Process Fundamentals of the Academy of Sciences of the Czech Republic, Rozvojova 135, 16502 Prague 6 - Suchdol (Czech Republic); Kastanek, Petr [Biocen, Ltd., Ondrickova 1246/13, 13000 Praha - Zizkov (Czech Republic)

    2010-03-15

    The aim of the study was the experimental verification of a proposed novel technology of energy and materials production, consisting of the following process steps: production of biogas from agricultural waste (distillery stillage), presumed utilization of biogas for electricity and heat production (cogeneration) in association with its use as a source of carbon dioxide for microalgae cultivation. The microalgal biomass can be hereafter processed to valuable products such as food and feed supplements. A part of the process wastewater can be utilized as a nitrogen source (ammonium ions) for microalgae cultivation, so the whole process is technologically closed. The tests were performed in a pilot-scale device. Optimization of biogas production from distillery stillage is described. The growth kinetics of microalgae Chlorella sp. consuming biogas or mixture of air and carbon dioxide in the concentration range of 2-20% (v/v) (simulating a flue gas from biogas incineration) in laboratory-scale photo-bioreactors are presented. It was proven that the raw biogas (even without the removal of hydrogen sulphide) could be used as a source of carbon dioxide for growth of microalgae. The growth rate of microalgae consuming biogas was the same as the growth rate of the culture grown on a mixture of air and food-grade carbon dioxide. Using biogas as a source of carbon dioxide has two main advantages: the biomass production costs are reduced and the produced biomass does not contain harmful compounds, which can occur in flue gases. The microalgal growth in bubbled cylinders was typically linear with time. The growth rate dependence on the diameter of the photobioreactor can be correlated using an empirical formula M = 2.2 D{sup -0.8} (valid for the linear bubbling velocities in the range of w = 0.1-0.3 cm/s), where M is the growth rate in g/L/h, and D is the photobioreactor diameter in mm. Processing of the fermenter wastewater was also quantified. Particularly the removal of

  4. Utilization of distillery stillage for energy generation and concurrent production of valuable microalgal biomass in the sequence: Biogas-cogeneration-microalgae-products

    International Nuclear Information System (INIS)

    Douskova, Irena; Kastanek, Frantisek; Maleterova, Ywette; Kastanek, Petr; Doucha, Jiri; Zachleder, Vilem

    2010-01-01

    The aim of the study was the experimental verification of a proposed novel technology of energy and materials production, consisting of the following process steps: production of biogas from agricultural waste (distillery stillage), presumed utilization of biogas for electricity and heat production (cogeneration) in association with its use as a source of carbon dioxide for microalgae cultivation. The microalgal biomass can be hereafter processed to valuable products such as food and feed supplements. A part of the process wastewater can be utilized as a nitrogen source (ammonium ions) for microalgae cultivation, so the whole process is technologically closed. The tests were performed in a pilot-scale device. Optimization of biogas production from distillery stillage is described. The growth kinetics of microalgae Chlorella sp. consuming biogas or mixture of air and carbon dioxide in the concentration range of 2-20% (v/v) (simulating a flue gas from biogas incineration) in laboratory-scale photo-bioreactors are presented. It was proven that the raw biogas (even without the removal of hydrogen sulphide) could be used as a source of carbon dioxide for growth of microalgae. The growth rate of microalgae consuming biogas was the same as the growth rate of the culture grown on a mixture of air and food-grade carbon dioxide. Using biogas as a source of carbon dioxide has two main advantages: the biomass production costs are reduced and the produced biomass does not contain harmful compounds, which can occur in flue gases. The microalgal growth in bubbled cylinders was typically linear with time. The growth rate dependence on the diameter of the photobioreactor can be correlated using an empirical formula M = 2.2 D -0.8 (valid for the linear bubbling velocities in the range of w = 0.1-0.3 cm/s), where M is the growth rate in g/L/h, and D is the photobioreactor diameter in mm. Processing of the fermenter wastewater was also quantified. Particularly the removal of ammonia

  5. Experimentation of grapevine cultivation in organic system, on five different Romanian vineyards

    Directory of Open Access Journals (Sweden)

    Aurora Maria Ranca

    2016-11-01

    Full Text Available In five Romanian vineyards, in 2013-2014 period was experimented organic system growing on  grape varieties for wine representative for each area, here are applied organic growing technology in parallel with the conventional (control. White varieties studied are: Chardonnay (Murfatlar and Valea Calugareasca, Sauvignon blanc and Muscat Ottonel(Tarnave, Feteasca regala (Tarnave, Bujoru and Copou-Iasi. Red varieties are Cabernet Sauvignon (Murfatlar and Valea Calugareasca and Merlot (Bujoru. Concerning evolution of main climatic factors for the years 2013-2014 it is show that the annual average air temperature increase compared with the average of the years 1991-2010; is observed an increasing in mean annual temperature, mean temperature during the growing season and the value of sum of sunshine hours. The water regime was kept constant, registering values close to the annual average, both during the growing season and at entire year. The weeds spectrum is represented both by dicotyledonous as knotweed (Polygonum aviculare, Veronica (Stellaria media, news (Amaranthus retroflexus, bindweed (Convolvurus arvensis and monocotyledonous as grass thick (Cynodon dactylon. Concerning the phytosanitary status, at Murfatlar were registered problems with oidium attack, with all main disease at Dealu Mare and with downy mildew at Bujoru. In all areas the pest has been found are: grape mouth (Lobesia botrana and spiders (Tetranichus sp.. Schemes of treatments focused generally on substances bassed on copper and sulfur to combat diseases and for pests have been used pheromonal traps or other certified organic products. The grapes harvest was lower in organic plots with till 25%; their quality being close at both growing variants.

  6. The use of PCR assay for quality testing of grain of winter wheat cultivated in organic, integrated, conventional system and monoculture in phytopathological aspect

    Directory of Open Access Journals (Sweden)

    Aleksander Łukanowski

    2012-12-01

    Full Text Available The aim of experiments was to evaluate the occurrence of fungi on grain of winter wheat cv. Roma cultivated in four systems on the experimental fields owned by the Institute of Soil Science and Plant Cultivation. Among pathogenic species, fungi from genus Fusarium dominated. Their number was the lowest on grain harvested in organic system and the highest in integrated one. Saprotrophic species were represented mainly by Alternaria alternata, which occurred the most often in organic system. Determination of F. avenaceum, F. culmorum and F. poae with microscope was confirmed with a PCR assay. All isolates of F. culmorum and F. poae gave an amplification product of Tri 5 gene coding the possibility of trichocene production, while none of isolates of F. avenaceum.

  7. Feasibility study of microalgal and jatropha biodiesel production plants: Exergy analysis approach

    International Nuclear Information System (INIS)

    Ofori-Boateng, Cynthia; Keat, Teong Lee; JitKang, Lim

    2012-01-01

    The exergy analyses performed in this study are based on three thermodynamic performance parameters namely exergy destruction, exergy efficiency and thermodynamic improvement potentials. After mathematical analysis with Aspen Plus software, the results showed that 64% and 44% of the total exergy content of the input resources into microalgal methyl ester (MME) and jatropha methyl ester (JME) production plants were destroyed respectively for 1 ton of biodiesel produced. This implies that only 36% and 56% (for MME and JME production plants respectively) useful energy in the products is available to do work. The highest and lowest exergy destructions were recorded in the oil extraction units (38% and 39% of the total exergy destroyed for MME and JME plants respectively) and transesterification units (5% and 2% of total exergy destroyed for MME and JME plants respectively) respectively for 1 ton biodiesel produced. Since sustainable biodiesel production depends on cultivation of feedstock, oil extraction and transesterification processes, exergy analysis which is carried out on only the transesterification unit cannot justify the thermodynamic feasibility of the whole biodiesel production plant unless a complete thermodynamic assessment has been done for the whole plant. Thus, according to this study which considers all the biodiesel production processes, MME and JME production plants are not thermodynamically feasible. - Highlights: ► 64% of exergy content of input resources into MME production plant is destroyed. ► 44% of exergy content of input resources into JME production plant is destroyed. ► Exergetic efficiencies of MME and JME production plants are far less than 1. ► Thermodynamically, MME and JME production plants are unsustainable. ► Exergy loss can be reduced by using heat integrated reactive distillation process.

  8. Cultivating usership?

    DEFF Research Database (Denmark)

    Petersen, Trine Brun; Riisberg, Vibeke

    2017-01-01

    , relatively little is known about clothing systems tailored for the private market. This article presents a case study of a recently launched subscription service for children’s clothing, which offered a range of eco-certified garments for rent as more or less complete wardrobes. Drawing on fashion scholar...

  9. Optimization of stocking density in intensification of mud crab Scylla serrata cultivation in the resirculation system

    Directory of Open Access Journals (Sweden)

    Yuni Puji Hastuti

    2017-07-01

    Full Text Available ABSTRACT This study aimed to determine optimum stocking density of mud crab Scylla serrata through the applied of different stocking density in every treatment in recirculation system. Experimental design used was complete randomized design (CRD with three density treatments which were 5 (P1, 10 (P2, and 15 ind/container (P3. All treatments replicated three times. The crab with the average of body weight 150 g/ind cultured in a plastic box (40×30×30 cm. Crab was cultured within 60 days and were fed two times a day by at satiation method. The result showed that P2 treatment gave the best result of mangrove crabs production performance among all treatments with 73.33±5.77% survival rate, 0.68±0.01 g/ind/day absolute growth rate and food conversion ratio 10.11±0.01. Treatment P1 gave the good response of stress, it indicated by the lowest glucose of all tretamnets at the level of 31.91 mg/dL in the end of treatment periods. The water quality during study period was fluctuative as affected by different stocking density in the treatments. Keywords: mud crab, stocking density, production performance  ABSTRAK Penelitian ini bertujuan untuk menentukan padat tebar optimal kepiting bakau Scylla serrata melalui penerapan kepadatan tebar yang berbeda pada setiap perlakuan dalam sistem resirkulasi. Rancangan penelitian yang digunakan adalah rancangan acak lengkap dengan tiga perlakuan yaitu 5 (P1, 10 (P2, dan 15 ekor/wadah pemeliharaan (P3 dengan tiga ulangan. Kepiting bakau yang digunakan memiliki berat rata-rata 150 g/ekor. Wadah pemeliharaan yang digunakan selama pemeliharaan adalah kontainer plastik yang berukuran 40×30×30 cm. Pemeliharaan kepiting bakau dilaksanakan selama 60 hari dan diberikan pakan berupa ikan rucah dua kali sehari secara at satiation. Penelitian menunjukkan bahwa perlakuan P2 memberikan hasil kinerja produksi terbaik dibandingkan perlakuan lainnya dengan nilai kelangsungan hidup 73,33±5,77%, laju pertumbuhan mutlak 0,68

  10. FY1995 microalgal biotechnology for recycling of pollutants; 1995 nendo tayona sorui kino wo kiban to suru seibutsuken busshitsu junkangta sogo saishigenka gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    The objectives are 1) development of biological processes needed for the treatment of pollutants and the conversion of resulting biomass to value added products such as energy and fine chemicals, and 2) development of techniques for monitoring of both biological and chemical hazards associated with process operation. We developed a microalgal system for simultaneous removal of CO{sub 2}/NO{sub x} from flue gas, as well as an electro-osmotic method for recovery of microalgal cells. A strategy for effective culturing of photoautotrophic cells in photobioreactors was also proposed. We utilized waste algal biomass to produce biosurfactants, and studied about structure-function relationship of lipopeptide biosurfactants. As an energy product, H{sub 2} was produced via lactic acid fermentation of algal biomass. Physiology of marine phytoplankton was also studied in relation to the future mass production of microalgal biomass. A rapid monitoring of microbial populations was possible by using fluorescent probes. An enzyme immunosorbent assay system specific to fish metallothionein was established for the assessment of aquatic environmental pollution. Human herpesvirus latent infection was effectively applied to biological assay of environmental hygiene. (NEDO)

  11. Fungal communities in mycorrhizal roots of conifer seedlings in forest nurseries under different cultivation systems, assessed by morphotyping, direct sequencing and mycelial isolation.

    Science.gov (United States)

    Menkis, Audrius; Vasiliauskas, Rimvydas; Taylor, Andrew F S; Stenlid, Jan; Finlay, Roger

    2005-12-01

    Fungi colonising root tips of Pinus sylvestris and Picea abies grown under four different seedling cultivation systems were assessed by morphotyping, direct sequencing and isolation methods. Roots were morphotyped using two approaches: (1) 10% of the whole root system from 30 seedlings of each species and (2) 20 randomly selected tips per plant from 300 seedlings of each species. The first approach yielded 15 morphotypes, the second yielded 27, including 18 new morphotypes. The overall community consisted of 33 morphotypes. The level of mycorrhizal colonisation of roots determined by each approach was about 50%. The cultivation system had a marked effect on the level of mycorrhizal colonisation. In pine, the highest level of colonisation (48%) was observed in bare-root systems, while in spruce, colonisation was highest in polyethylene rolls (71%). Direct internal transcribed spacer ribosomal DNA sequencing and isolation detected a total of 93 fungal taxa, including 27 mycorrhizal. A total of 71 (76.3%) fungi were identified at least to a genus level. The overlap between the two methods was low. Only 13 (13.9%) of taxa were both sequenced and isolated, 47 (50.5%) were detected exclusively by sequencing and 33 (35.5%) exclusively by isolation. All isolated mycorrhizal fungi were also detected by direct sequencing. Characteristic mycorrhizas were Phialophora finlandia, Amphinema byssoides, Rhizopogon rubescens, Suillus luteus and Thelephora terrestris. There was a moderate similarity in mycorrhizal communities between pine and spruce and among different cultivation systems.

  12. Kinetics of inorganic carbon utilization by microalgal biofilm in a flat plate photoreactor

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Y.H.; Leu, J.Y.; Lan, C.R.; Lin, P.H.P.; Chang, F.L. [Development Center for Biotechnology, Taipei (Taiwan). Dept. for Environmental Program

    2003-11-01

    A kinetic model was developed to describe inorganic carbon utilization by microalgae biofilm in a flat plate photoreactor. The model incorporates the fundamental mechanisms of diffusive mass transport and biological reaction of inorganic carbon by microalgal biofilm. An advanced numerical technique, the orthogonal collocation method and Gear's method, was employed to solve this kinetic model. The model solutions included the concentration profiles of inorganic carbon in the microalgal biofilm, the growths of suspended microalgae and microalgal biofilm, the effluent concentrations of inorganic carbon, and the flux of inorganic carbon from bulk liquid into biofilm. The batch kinetic test was independently conducted to determine biokinetic parameters used in the microalgal biofilm model simulation while initial thickness of microalgal biofilm were assumed. A laboratory-scale flat plate photoreactor with a high recycle flow rate was set up and conducted to verify the model. The volume of photoreactor is 60 l which yields a hydraulic retention time of 1.67 days. The model-generated inorganic carbon and the suspended microalgae concentration curves agreed well with those obtained in the laboratory-scale test. The fixation efficiencies of HCO{sub 3}{sup -} and CO{sub 2} are 98.5% and 90% at a steady-state condition, respectively. The concentration of suspended microalgal cell reached up to 12 mg/l at a maximum growth rate while the thickness of microalgal biofilm was estimated to be 104 pm at a steady-state condition. The approaches of experiments and model simulation presented in this study could be employed for the design of a flat plate photoreactor to treat CO{sub 2} by microalgal biofilm in a fossil-fuel power plant.

  13. Report on achievements in fiscal 1998. Venture business growing type consortium - small business creating infrastructure (Development of ultra-high efficiency cultivation system for Hyphomycetes, and application of the system to plant device to manufacture fermentative foods); 1998 nendo itojokin no chokoritsu tairyo baiyo system no kaihatsu to kinosei hakko sho0kuhin seizo plant kiki eno tekiyo seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    This project has noticed the membrane surface liquid culture method, and researched and developed the following themes with an objective to commercialize the membrane surface liquid culture system and develop novel fermentative foods using this system. Cultivation of Beni-koji bacteria (solid culture of M. pilosus k) is taken up in the model cultivation system. (1) establishment of the membrane surface liquid culture system and development of devices, (2) elucidation of cultivation characteristics of the membrane surface liquid culture system and optimization of the cultivating conditions, and (3) development of fermentative foods. In Item (1), such problems were solved as automation of bacteria planting, long-term pasteurized cultivation, and assurance of clean cultivation broth. In Item (2), it was discovered most suitable that maltose concentration is about 5%, glutamic acid concentration is about 50 mM, the initial culture medium pH is about six, and the cultivation temperature is 30 degree C. In item (3), as a result of mixing this red coloring matter containing cultivation broth into preparation of Miso (bean paste) and soy sauce, products having high {gamma}-Aminobutyric acid and monacholin k content were developed. In addition, while Beni-koji made by solid cultivation had peculiar taste and odor, this drawback was eliminated by using this coloring matter containing cultivation broth. This has made differentiation from conventional products possible. (NEDO)

  14. Extraction of microalgal lipids and the influence of polar lipids on biodiesel production by lipase-catalyzed transesterification.

    Science.gov (United States)

    Navarro López, Elvira; Robles Medina, Alfonso; González Moreno, Pedro Antonio; Esteban Cerdán, Luis; Molina Grima, Emilio

    2016-09-01

    In order to obtain microalgal saponifiable lipids (SLs) fractions containing different polar lipid (glycolipids and phospholipids) contents, SLs were extracted from wet Nannochloropsis gaditana microalgal biomass using seven extraction systems, and the polar lipid contents of some fractions were reduced by low temperature acetone crystallization. We observed that the polar lipid content in the extracted lipids depended on the polarity of the first solvent used in the extraction system. Lipid fractions with polar lipid contents between 75.1% and 15.3% were obtained. Some of these fractions were transformed into fatty acid methyl esters (FAMEs, biodiesel) by methanolysis, catalyzed by the lipases Novozym 435 and Rhizopus oryzae in tert-butanol medium. We observed that the reaction velocity was higher the lower the polar lipid content, and that the final FAME conversions achieved after using the same lipase batch to catalyze consecutive reactions decreased in relation to an increase in the polar lipid content. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Cultivated Sea Lettuce is a Multiorgan Protector from Oxidative and Inflammatory Stress by Enhancing the Endogenous Antioxidant Defense System

    Science.gov (United States)

    Ratnayake, Ranjala; Liu, Yanxia; Paul, Valerie J.; Luesch, Hendrik

    2013-01-01

    The health-promoting effects of seaweeds have been linked to antioxidant activity that may counteract cancer-causing oxidative stress-induced damage and inflammation. While antioxidant activity is commonly associated with direct radical scavenging activity, an alternative way to increase the antioxidant status of a cell is to enhance the endogenous (phase II) defense system consisting of cytoprotective antioxidant enzymes, including NAD(P)H:quinone oxidoreductase 1 (NQO1). These enzymes are transcriptionally regulated by the antioxidant response element (ARE) via the transcription factor Nrf2. Extracts derived from cultivated Ulva sp., a green alga regarded as a marine vegetable (sea lettuce), potently activated the Nrf2-ARE pathway in IMR-32 neuroblastoma and LNCaP prostate cancer cells. RNA interference studies demonstrated that Nrf2 and PI3 kinase are essential for the phase II response in IMR-32 cells. Activity-enriched fractions induced Nrf2 nuclear translocation and target gene transcription, and boosted the cellular glutathione level and therefore antioxidant status. A single-dose gavage feeding of Ulva-derived fractions increased Nqo1 transcript levels in various organs. Nqo1 induction spiked in different tissues, depending on the specific chemical composition of each administered fraction. We purified and characterized four ARE inducers in this extract, including loliolide (1), isololiolide (2), a megastigmen (3), and a novel chlorinated unsaturated aldehyde (4). The ARE-active fractions attenuated lipopolysaccharide-induced iNOS and Cox2 gene expression in macrophagic RAW264.7 cells, decreasing nitric oxide (NO) and prostaglandin E2 (PGE2) production, respectively. Nqo1 activity and NO production were abrogated in nrf2−/− mouse embryonic fibroblasts, providing a direct link between the induction of phase II response and anti-inflammatory activity. PMID:24005795

  16. Influence of Crop Nutrition on Grain Yield, Seed Quality and Water Productivity under Two Rice Cultivation Systems

    Directory of Open Access Journals (Sweden)

    Y.V. SINGH

    2013-03-01

    Full Text Available The system of rice intensification (SRI is reported to have advantages like lower seed requirement, less pest attack, shorter crop duration, higher water use efficiency and the ability to withstand higher degree of moisture stress than traditional method of rice cultivation. With this background, SRI was compared with traditional transplanting technique at Indian Agricultural Research Institute, New Delhi, India during two wet seasons (2009–2011. In the experiment laid out in a factorial randomized block design, two methods of rice cultivation [conventional transplanting (CT and SRI] and two rice varieties (Pusa Basmati 1 and Pusa 44 were used under seven crop nutrition treatments, viz. T1, 120 kg/hm2 N, 26.2 kg/hm2 P and 33 kg/hm2 K; T2, 20 t/hm2 farmyard manure (FYM; T3, 10 t/hm2 FYM + 60 kg/hm2 N; T4, 5 t/hm2 FYM + 90 kg/hm2 N; T5, 5 t/hm2 FYM + 60 kg/hm2 N + 1.5 kg/hm2 blue green algae (BGA; T6, 5 t/hm2 FYM + 60 kg/hm2 N + 1.0 t/hm2 Azolla, and T7, N0P0K0 (control, no NPK application to study the effect on seed quality, yield and water use. In SRI, soil was kept at saturated moisture condition throughout vegetative phase and thin layer of water (2–3 cm was maintained during the reproductive phase of rice, however, in CT, standing water was maintained in crop growing season. Results revealed that CT and SRI gave statistically at par grain yield but straw yield was significantly higher in CT as compared to SRI. Seed quality was superior in SRI as compared to CT. Integrated nutrient management (INM resulted in higher plant height with longer leaves than chemical fertilizer alone in both the rice varieties. Grain yield attributes such as number of effective tillers per hill, panicle length and panicle weight of rice in both the varieties were significantly higher in INM as compared to chemical fertilizer alone. Grain yields of both the varieties were the highest in INM followed by the recommended doses of chemical fertilizer. The grain yield

  17. Characterising rice-based farming systems to identify opportunities for adopting water efficient cultivation methods in Tamil Nadu, India

    NARCIS (Netherlands)

    Senthilkumar, K.; Bindraban, P.S.; Boer, de W.J.; Ridder, de N.; Thiyagarajan, T.M.; Giller, K.E.

    2009-01-01

    Efficient water use in rice cultivation is a prerequisite for sustaining food security for the rice consuming population of India. Novel rice production practices, including water-saving techniques, modifications in transplanting, spacing, weeding and nutrient management, have been developed and

  18. Rice cultivation in the farming systems of Sukumaland, Tanzania : a quest for sustainable production under structural adjustment programmes

    NARCIS (Netherlands)

    Meertens, H.C.C.

    1999-01-01

    This thesis investigates options for sustainable rice cultivation and general agricultural development in the Mwanza and Shinyanga regions in northwestern Tanzania, often called Sukumaland due to the predominance of Wasukuma people. Generally Sukumaland has a semi-arid climate; agriculture

  19. An integrated ecosystem approach for assessing the potential role of cultivated bivalve shells as part of the carbon trading system

    NARCIS (Netherlands)

    Filgueira, R.; Byron, C.J.; Comeau, L.A.; Jansen, H.M.; Smaal, A.C.

    2015-01-01

    The role of bivalve mariculture in the CO2 cycle has been commonly evaluated as the balance between respiration, shell calcium carbonate sequestration and CO2 release during biogenic calcification. However, this approach neglects the ecosystem implications of cultivating bivalves at high densities,

  20. Microalgal technology for remediation of CO{sub 2} from power plant flue gas: A techno-economic perspective

    Energy Technology Data Exchange (ETDEWEB)

    Kadam, K.L. [National Renewable Energy Lab., Golden, CO (United States)

    1996-12-31

    Power plants burning fossil fuels are a major source of CO{sub 2} which is implicated in global warming. Microalgal systems which photosynthetically assimilate carbon dioxide can be used for mitigation of this major greenhouse gas. A techno-economic model was developed for trapping carbon dioxide from flue gases by microalgae in outdoor ponds. The model also shows that algal lipid content and growth rate are both important for an economical process, but a trade-off exists between the two, i.e., a high lipid content and low growth rate combination can be as effective as a low lipid content and high growth rate combination. Hence, these two parameters may be treated as a composite parameter to be optimized to yield the least CO{sub 2} mitigation cost. Model predictions were also used to compare the microalgal technology with alternative technologies in terms of CO{sub 2} mitigation costs. Incorporating advances anticipated in the future into the design basis, the model yields a CO{sub 2} mitigation cost that is competitive with other CO{sub 2} remediation technologies currently being proposed. Furthermore, this technology also provides a lipid feedstock for producing a renewable fuel such as biodiesel. Deployment of this technology for CO{sub 2} mitigation looks attractive if research goals put forth by the model are achieved.

  1. Characterization of nutrient removal and microalgal biomass production on an industrial waste-stream by application of the deceleration-stat technique

    DEFF Research Database (Denmark)

    Van Wagenen, Jonathan; Pape, Mathias Leon; Angelidaki, Irini

    2015-01-01

    Industrial wastewaters can serve as a nutrient and water source for microalgal production. In this study the effluent of an internal circulation (IC) reactor anaerobically treating the wastes of a biotechnology production facility were chosen as the cultivation medium for Chlorella sorokiniana...... in batch and continuous cultures. The aim was to evaluate the rates of nutrient removal and biomass production possible at various dilution rates. The results demonstrate that the industrial wastewater served as a highly effective microalgae culture medium and that dilution rate strongly influenced algae...... photon m2s-1) established the optimal dilution rates to reach volumetric productivity of 5.87 and 1.67gL-1day-1 respectively. The corresponding removal rates of nitrogen were 238 and 93mg L-1day-1 and 40 and 19mg L-1day-1 for phosphorous. The yield on photons at low light intensity was as high as had...

  2. An integrated microalgal growth model and its application to optimize the biomass production of Scenedesmus sp. LX1 in open pond under the nutrient level of domestic secondary effluent.

    Science.gov (United States)

    Wu, Yin-Hu; Li, Xin; Yu, Yin; Hu, Hong-Ying; Zhang, Tian-Yuan; Li, Feng-Min

    2013-09-01

    Microalgal growth is the key to the coupled system of wastewater treatment and microalgal biomass production. In this study, Monod model, Droop model and Steele model were incorporated to obtain an integrated growth model describing the combined effects of nitrogen, phosphorus and light intensity on the growth rate of Scenedesmus sp. LX1. The model parameters were obtained via fitting experimental data to these classical models. Furthermore, the biomass production of Scenedesmus sp. LX1 in open pond under nutrient level of secondary effluent was analyzed based on the integrated model, predicting a maximal microalgal biomass production rate about 20 g m(-2) d(-1). In order to optimize the biomass production of open pond the microalgal biomass concentration, light intensity on the surface of open pond, total depth of culture medium and hydraulic retention time should be 500 g m(-3), 16,000 lx, 0.2 m and 5.2 d in the conditions of this study, respectively. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Biocapture of CO2 by Different Microalgal-Based Technologies for Biogas Upgrading and Simultaneous Biogas Slurry Purification under Various Light Intensities and Photoperiods

    Science.gov (United States)

    Guo, Pengfei; Zhang, Yuejin; Zhao, Yongjun

    2018-01-01

    Co-cultivation of microalgae and microbes for pollutant removal from sewage is considered as an effective wastewater treatment method. The aim of this study is to screen the optimal photoperiod, light intensity and microalgae co-cultivation method for simultaneously removing nutrients in biogas slurry and capturing CO2 in biogas. The microalgae–fungi pellets are deemed to be a viable option because of their high specific growth rate and nutrient and CO2 removal efficiency under the photoperiod of 14 h light:10 h dark. The order of both the biogas slurry purification and biogas upgrading is ranked the same, that is Chlorella vulgaris–Ganoderma lucidum > Chlorella vulgaris–activated sludge > Chlorella vulgaris under different light intensities. For all cultivation methods, the moderate light intensity of 450 μmol m−2 s−1 is regarded as the best choice. This research revealed that the control of photoperiod and light intensity can promote the biological treatment process of biogas slurry purification and biogas upgrading using microalgal-based technology. PMID:29543784

  4. Biocapture of CO2 by Different Microalgal-Based Technologies for Biogas Upgrading and Simultaneous Biogas Slurry Purification under Various Light Intensities and Photoperiods

    Directory of Open Access Journals (Sweden)

    Pengfei Guo

    2018-03-01

    Full Text Available Co-cultivation of microalgae and microbes for pollutant removal from sewage is considered as an effective wastewater treatment method. The aim of this study is to screen the optimal photoperiod, light intensity and microalgae co-cultivation method for simultaneously removing nutrients in biogas slurry and capturing CO2 in biogas. The microalgae–fungi pellets are deemed to be a viable option because of their high specific growth rate and nutrient and CO2 removal efficiency under the photoperiod of 14 h light:10 h dark. The order of both the biogas slurry purification and biogas upgrading is ranked the same, that is Chlorella vulgaris–Ganoderma lucidum > Chlorella vulgaris–activated sludge > Chlorella vulgaris under different light intensities. For all cultivation methods, the moderate light intensity of 450 μmol m−2 s−1 is regarded as the best choice. This research revealed that the control of photoperiod and light intensity can promote the biological treatment process of biogas slurry purification and biogas upgrading using microalgal-based technology.

  5. Biofilm Attached Cultivation of Chlorella pyrenoidosa Is a Developed System for Swine Wastewater Treatment and Lipid Production

    Directory of Open Access Journals (Sweden)

    Pengfei Cheng

    2017-09-01

    Full Text Available This study showed the new potential of using soluble contents and heavy metals in swine wastewater as nutrient supplements for the algae Chlorella pyrenoidosa with biofilm attached method. Algae with biofilm attached cultivation grew well in unpasteurized wastewater reaching a biomass productivity of 5.03 g m−2 d−1, lipid content of 35.9% and lipid productivity of 1.80 g m−2 d−1. Chlorella grew in BG11 medium delivered lower values for each of the aforementioned parameters. The FAMEs compositions in the algae paste were mainly consisted of C16:0, C18:2, and C18:3. Algae removed NH4+–N, total phosphorus (TP, and COD by 75.9, 68.4, and 74.8%, respectively. Notably, Zn2+, Cu+, and Fe2+ were removed from wastewater with a ratio of 65.71, 53.64, and 58.89%, respectively. Biofilm attached cultivation of C. pyrenoidosa in swine wastewater containing heavy metals could accumulate considerable biomass and lipid, and the removal ratio of NH4+–N, TP, COD, and as well as heavy metal were high. Treatment of wastewater with biofilm attached cultivation showed an increasingly popular for the concentration of microalgae and environmental sustainability.

  6. Biofilm Attached Cultivation of Chlorella pyrenoidosa Is a Developed System for Swine Wastewater Treatment and Lipid Production

    Science.gov (United States)

    Cheng, Pengfei; Wang, Yuanzhu; Liu, Tianzhong; Liu, Defu

    2017-01-01

    This study showed the new potential of using soluble contents and heavy metals in swine wastewater as nutrient supplements for the algae Chlorella pyrenoidosa with biofilm attached method. Algae with biofilm attached cultivation grew well in unpasteurized wastewater reaching a biomass productivity of 5.03 g m−2 d−1, lipid content of 35.9% and lipid productivity of 1.80 g m−2 d−1. Chlorella grew in BG11 medium delivered lower values for each of the aforementioned parameters. The FAMEs compositions in the algae paste were mainly consisted of C16:0, C18:2, and C18:3. Algae removed NH4+–N, total phosphorus (TP), and COD by 75.9, 68.4, and 74.8%, respectively. Notably, Zn2+, Cu+, and Fe2+ were removed from wastewater with a ratio of 65.71, 53.64, and 58.89%, respectively. Biofilm attached cultivation of C. pyrenoidosa in swine wastewater containing heavy metals could accumulate considerable biomass and lipid, and the removal ratio of NH4+–N, TP, COD, and as well as heavy metal were high. Treatment of wastewater with biofilm attached cultivation showed an increasingly popular for the concentration of microalgae and environmental sustainability. PMID:28983302

  7. Jatropha curcas and Ricinus communis differentially affect arbuscular mycorrhizal fungi diversity in soil when cultivated for biofuel production in a Guantanamo (Cuba) tropical system.

    Science.gov (United States)

    Alguacil, M. M.; Torrecillas, E.; Hernández, G.; Torres, P.; Roldán, A.

    2012-04-01

    The arbuscular mycorrhizal fungi (AMF) are a key, integral component of the stability, sustainability and functioning of ecosystems. In this study, we characterised the AMF biodiversity in a control soil and in a soil cultivated with Jatropha curcas or Ricinus communis, in a tropical system in Guantanamo (Cuba), in order to verify if a change of land use to biofuel plant production had any effect on the AMF communities. We also asses whether some soil properties related with the soil fertility (total N, Organic C, microbial biomass C, aggregate stability percentage, pH and electrical conductivity) were changed with the cultivation of both crop species. The AM fungal small sub-unit (SSU) rRNA genes were subjected to PCR, cloning, sequencing and phylogenetic analyses. Twenty AM fungal sequence types were identified: 19 belong to the Glomeraceae and one to the Paraglomeraceae. Two AMF sequence types related to cultured AMF species (Glo G3 for Glomus sinuosum and Glo G6 for Glomus intraradices-G. fasciculatum-G. irregulare) disappeared in the soil cultivated with J. curcas and R. communis. The soil properties (total N, Organic C and microbial biomass C) were improved by the cultivation of the two plant species. The diversity of the AMF community decreased in the soil of both crops, with respect to the control soil, and varied significantly depending on the crop species planted. Thus, R. communis soil showed higher AMF diversity than J. curcas soil. In conclusion, R. communis could be more suitable in long-term conservation and sustainable management of these tropical ecosystems.

  8. Use of diluted urine for cultivation of Chlorella vulgaris.

    Science.gov (United States)

    Jaatinen, Sanna; Lakaniemi, Aino-Maija; Rintala, Jukka

    2016-01-01

    Our aim was to study the biomass growth of microalga Chlorella vulgaris using diluted human urine as a sole nutrient source. Batch cultivations (21 days) were conducted in five different urine dilutions (1:25-1:300), in 1:100-diluted urine as such and with added trace elements, and as a reference, in artificial growth medium. The highest biomass density was obtained in 1:100-diluted urine with and without additional trace elements (0.73 and 0.60 g L(-1), respectively). Similar biomass growth trends and densities were obtained with 1:25- and 1:300-diluted urine (0.52 vs. 0.48 gVSS L(-1)) indicating that urine at dilution 1:25 can be used to cultivate microalgal based biomass. Interestingly, even 1:300-diluted urine contained sufficiently nutrients and trace elements to support biomass growth. Biomass production was similar despite pH-variation from < 5 to 9 in different incubations indicating robustness of the biomass growth. Ammonium formation did not inhibit overall biomass growth. At the beginning of cultivation, the majority of the biomass consisted of living algal cells, while towards the end, their share decreased and the estimated share of bacteria and cell debris increased.

  9. Microalgal biotechnologies for recycling of pollutants; Tayona sorui kino wo kiban to suru seibutsuken busshitsu junkangata sogo saishigenka gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    Miyamoto, K; Nasu, M; Hashimoto, C; Tanaka, K; Hirata, M [Osaka University, Osaka (Japan). Faculty of Pharmaceutial Science; Fujita, M; Takagi, M [Osaka University, Osaka (Japan). Faculty of Engineering; Hirata, Y; Taya, M [Osaka University, Osaka (Japan). Faculty of Engineering Science; Yamanishi, H [Osaka University, Osaka (Japan). Faculty of Medicine

    1997-02-01

    This paper describes the technology development by which biomass is produced by treatment of pollutants using microalgae, and is recycled. A bioreactor system has been developed, in which microalgal biomass can be obtained through the effective treatment of CO2 and NOx using microalgae having ability of increase under the severe condition with simultaneous flow of CO2 and NOx. A new method has been also developed for separating and recovering the microalgae. Materials, such as glucose, glycerol, acetic acid, and lactic acid, were produced from the obtained biomass through physico-chemical and biological treatments. These materials can be converted into ethanol and hydrogen. For this treatment and recycling system, functions as a part of natural material recycling were considered to be most significant. Development of an analysis and evaluation method of an impact of this system on the natural environment is also tried. 1 fig.

  10. The effect of light supply on microalgal growth, CO2 uptake and nutrient removal from wastewater

    International Nuclear Information System (INIS)

    Gonçalves, A.L.; Simões, M.; Pires, J.C.M.

    2014-01-01

    Highlights: • Effect of irradiance and light:dark ratio on microalgal growth was analysed. • Microalgal growth, CO 2 capture, nitrogen and phosphorus uptake were evaluated. • Higher irradiances and light periods supported higher growth and CO 2 uptake rates. • All the studied microalgal strains have shown high nitrogen removal efficiencies. • The highest phosphorus removal efficiency was 67.6%. - Abstract: Microalgal based biofuels have been reported as an attractive alternative for fossil fuels, since they constitute a renewable energy source that reduces greenhouse gas emissions to the atmosphere. However, producing biofuels from microalgae is still not economically viable. Therefore, the integration of biofuel production with other microalgal applications, such as CO 2 capture and nutrient removal from wastewaters, would reduce the microalgal production costs (and the environmental impact of cultures), increasing the economic viability of the whole process. Additionally, producing biofuels from microalgae strongly depends on microalgal strain and culture conditions. This study evaluates the effect of culture conditions, namely light irradiance (36, 60, 120 and 180 μE m −2 s −1 ) and light:dark ratio (10:14, 14:10 and 24:0), on microalgal growth, atmospheric CO 2 uptake and nutrient (nitrogen and phosphorous) removal from culture medium. Four different microalgal strains, Chlorella vulgaris, Pseudokirchneriella subcapitata, Synechocystis salina and Microcystis aeruginosa, were studied to ascertain the most advantageous regarding the referred applications. This study has shown that higher light irradiance values and light periods resulted in higher specific growth rates and CO 2 uptake rates. C. vulgaris presented the highest specific growth rate and CO 2 uptake rate: 1.190 ± 0.041 d −1 and 0.471 ± 0.047 g CO2 L −1 d −1 , respectively. All the strains have shown high nitrogen removal efficiencies, reaching 100% removal percentages in

  11. The effect of irrigation, soil cultivation system and nitrogen fertilizer on the vitality and content of selected sugars in Vicia faba seed

    Energy Technology Data Exchange (ETDEWEB)

    Kurasiak-Popowska, D.; Szukala, J.; Gulewicz, K.

    2009-07-01

    In this study the influence of sprinkler irrigation, various soil cultivation systems (conventional, reduced tillage, zero tillage system) and the level (0, 30, 60, 90 kg N ha{sup -}1) of nitrogen (N) fertilization on the vitality and content of selected sugars in faba bean seeds (Vicia faba L.) of the cultivar Nadwislanski was examined. Sprinkler irrigation of faba bean improved seed energy and germination in all three years of the study (1999-2001) - on average germination energy by 8.8% and total germination by 3.2%-. Germination of faba bean seed under conventional tillage in the drier years was significantly higher than in the zero tillage system. In the wetter year, seed from both simplified systems produced seeds with higher germination than in traditional conventional tillage. Nitrogen (N) fertilizer affected germination energy, but had no effect on faba bean germination. Sprinkler irrigation and N fertilization had no effect on the content of the sugars studied in the faba bean seed. However, the stachyose content of faba bean seeds from conventional tilled plants was significantly higher than in seed of zero tilled plants (0.78 mg g{sup -}1 seed dm), and the galactose content of seed from zero tilled plants was significantly higher than in the other two cultivation systems - 0.34 and 0.28 mg g{sup -}1 seed dm in seeds from conventional and reduced tillage system, respectively. Additional key words: agronomic treatment, faba bean seeds, RFOs sugars. (Author) 24 refs.

  12. KAJIAN INPUT ENERGI PADA BUDIDAYA PADI METODE SYSTEM OF RICE INTENSIFICATION Studies on Energy Input in System of Rice Intensification Method of Rice Cultivation

    Directory of Open Access Journals (Sweden)

    Bambang Purwantana

    2012-05-01

    Full Text Available System of Rice Intensification (SRI is a rice cultivation method that intensively control and manage macro and micro nutrients as well as irrigation. This paper quantifies and compares the energy uses of SRI and conventional rice cultiva- tion systems. The study was conducted at some SRI’s experimental plots in the districts of Sleman, Kulonprogo, and Bantul, the province of Yogyakarta. The calculation of the energy was based on the farmers’ work schedule, the time required for each operation, the number of laborers, machines, tools, fuel, and all materials and inputs used. The result shows that SRI method consumed 35% less energy to conventional rice cultivation. Energy inputs from seed, water, fertilizer and pesticide were significantly reduces. However, there was higher input of human energy due to compost- ing, land preparation and weeding operations. The specific energy of SRI method was 1.96 MJ ha-1 lower than conven- tional method of 4.43 MJ ha-1. In the SRI method, 56.2 % of energy consumed was classified as direct energy and 43.8% was indirect energy. The SRI method used 61.9 % of renewable energy and 38.1 % of non-renewable energy. The working efficiency in composting and weeding operations should be improved in perspective of machine and tools to reduce the use of human energy. ABSTRAK System of Rice Intensification (SRI, merupakan suatu metode budidaya padi secara intensif dengan pengendalian unsur-unsur hara makro dan mikro disertai pengendalian dan pengaturan kebutuhan air. Penelitian ini bertujuan untuk menganalisis penggunaan energi dan mengidentifikasi kemungkinan penghematan energi pada budidaya padi SRI. Pe- nelitian dilakukan di Kabupaten Sleman, Kulonprogo, dan Bantul, Propinsi Daerah Istimewa Yogyakarta. Pengamatan dilakukan pada plot-plot percobaan budidaya padi SRI dengan melakukan audit seluruh input energi selama proses budidaya dan dikomparasikan dengan input energi pada budidaya padi cara konvensional. Hasil

  13. Effect of microalgal treatments on pesticides in water.

    Science.gov (United States)

    Hultberg, Malin; Bodin, Hristina; Ardal, Embla; Asp, Håkan

    2016-01-01

    The effect of the microalgae Chlorella vulgaris on a wide range of different pesticides in water was studied. Treatments included short-term exposure (1 h) to living and dead microalgal biomass and long-term exposure (4 days) to actively growing microalgae. The initial pesticide concentration was 63.5 ± 3.9 µg L(-1). There was no significant overall reduction of pesticides after short-term exposure. A significant reduction of the total amount of pesticides was achieved after the long-term exposure to growing microalgae (final concentration 29.7 ± 1.0 µg L(-1)) compared with the long-term control (37.0 ± 1.2 µg L(-1)). The concentrations of 10 pesticides out of 38 tested were significantly lowered in the long-term algal treatment. A high impact of abiotic factors such as sunlight and aeration for pesticide reduction was observed when the initial control (63.5 ± 3.9 µg L(-1)) and the long-term control (37.0 ± 1.2 µg L(-1)) were compared. The results suggest that water treatment using microalgae, natural inhabitants of polluted surface waters, could be further explored not only for removal of inorganic nutrients but also for removal of organic pollutants in water.

  14. Aggregate formation affects ultrasonic disruption of microalgal cells.

    Science.gov (United States)

    Wang, Wei; Lee, Duu-Jong; Lai, Juin-Yih

    2015-12-01

    Ultrasonication is a cell disruption process of low energy efficiency. This study dosed K(+), Ca(2+) and Al(3+) to Chlorella vulgaris cultured in Bold's Basal Medium at 25°C and measured the degree of cell disruption under ultrasonication. Adding these metal ions yielded less negatively charged surfaces of cells, while with the latter two ions large and compact cell aggregates were formed. The degree of cell disruption followed: control=K(+)>Ca(2+)>Al(3+) samples. Surface charges of cells and microbubbles have minimal effects on the microbubble number in the proximity of the microalgal cells. Conversely, cell aggregates with large size and compact interior resist cell disruption under ultrasonication. Staining tests revealed high diffusional resistance of stains over the aggregate interior. Microbubbles may not be effective generated and collapsed inside the compact aggregates, hence leading to low cell disruption efficiencies. Effective coagulation/flocculation in cell harvesting may lead to adverse effect on subsequent cell disruption efficiency. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Nanocellulose size regulates microalgal flocculation and lipid metabolism

    Science.gov (United States)

    Yu, Sun Il; Min, Seul Ki; Shin, Hwa Sung

    2016-01-01

    Harvesting of microalgae is a cost-consuming step for biodiesel production. Cellulose has recently been studied as a biocompatible and inexpensive flocculant for harvesting microalgae via surface modifications such as cation-modifications. In this study, we demonstrated that cellulose nanofibrils (CNF) played a role as a microalgal flocculant via its network geometry without cation modification. Sulfur acid-treated tunicate CNF flocculated microalgae, but cellulose nanocrystals (CNC) did not. In addition, desulfurization did not significantly influence the flocculation efficiency of CNF. This mechanism is likely related to encapsulation of microalgae by nanofibrous structure formation, which is derived from nanofibrils entanglement and intra-hydrogen bonding. Moreover, flocculated microalgae were subject to mechanical stress resulting in changes in metabolism induced by calcium ion influx, leading to upregulated lipid synthesis. CNF do not require surface modifications such as cation modified CNC and flocculation is derived from network geometry related to nanocellulose size; accordingly, CNF is one of the least expensive cellulose-based flocculants ever identified. If this flocculant is applied to the biodiesel process, it could decrease the cost of harvest, which is one of the most expensive steps, while increasing lipid production. PMID:27796311

  16. Toxicity of the pharmaceutical clotrimazole to marine microalgal communities

    International Nuclear Information System (INIS)

    Porsbring, Tobias; Blanck, Hans; Tjellstroem, Henrik; Backhaus, Thomas

    2009-01-01

    Clotrimazole belongs to the group of 14α-demethylase inhibiting fungicides. It is widely used in human and veterinary medicine and has been identified as a priority pollutant for the marine environment. However, the toxicity of clotrimazole to marine primary producers is largely unknown. We therefore sampled natural microalgal communities (periphyton) and exposed them to concentration series of clotrimazole over 4 days. 50 pmol/L clotrimazole caused a concentration-dependent accumulation of C14α-methylated sterol precursors, which coincided with a decrease in algal-specific C14-desmethyl sterols. This indicates an inhibition of algal 14α-demethylases already at environmental concentrations. A clotrimazole concentration of 500 pmol/L reduced total sterol content to 64% of control level. Community chlorophyll a content was affected by clotrimazole in a bi-phasic manner with first reductions becoming visible at 500 pmol/L, along with indications of an altered cycling of photoprotective xanthophyll pigments. Concentrations of 10-100 nmol/L and higher caused large reductions in community growth, and changed community pigment profiles in a concentration-dependent monotonous manner. The study further indicated that diatoms use obtusifoliol as a natural substrate for 14α-demethylase, just as higher plants do but also utilize norlanosterol

  17. Treatment of cattle-slaughterhouse wastewater and the reuse of sludge for biodiesel production by microalgal heterotrophic bioreactors

    Directory of Open Access Journals (Sweden)

    Mariana Manzoni Maroneze

    2014-12-01

    Full Text Available Microalgal heterotrophic bioreactors are a potential technological development that can convert organic matter, nitrogen and phosphorus of wastewaters into a biomass suitable for energy production. The aim of this work was to evaluate the performance of microalgal heterotrophic bioreactors in the secondary treatment of cattle-slaughterhouse wastewater and the reuse of microalgal sludge for biodiesel production. The experiments were performed in a bubble column bioreactor using the microalgae Phormidium sp. Heterotrophic microalgal bioreactors removed 90 % of the chemical oxygen demand, 57 % of total nitrogen and 52 % of total phosphorus. Substantial microalgal sludge is produced in the process (substrate yield coefficient of 0.43 mg sludge mg chemical oxygen demand−¹, resulting in a biomass with high potential for producing biodiesel (ester content of more than 99 %, cetane number of 55, iodine value of 73.5 g iodine 100 g−¹, unsaturation degree of ~75 % and a cold filter plugging point of 5 ºC.

  18. Optimal processing pathway for the production of biodiesel from microalgal biomass: A superstructure based approach

    DEFF Research Database (Denmark)

    Rizwan, Muhammad; Lee, Jay H.; Gani, Rafiqul

    2013-01-01

    In this study, we propose a mixed integer nonlinear programming (MINLP) model for superstructure based optimization of biodiesel production from microalgal biomass. The proposed superstructure includes a number of major processing steps for the production of biodiesel from microalgal biomass......, such as the harvesting of microalgal biomass, pretreatments including drying and cell disruption of harvested biomass, lipid extraction, transesterification, and post-transesterfication purification. The proposed model is used to find the optimal processing pathway among the large number of potential pathways that exist...... for the production of biodiesel from microalgae. The proposed methodology is tested by implementing on a specific case with different choices of objective functions. The MINLP model is implemented and solved in GAMS using a database built in Excel. The results from the optimization are analyzed...

  19. Microalgal bioengineering for sustainable energy development: Recent transgenesis and metabolic engineering strategies.

    Science.gov (United States)

    Banerjee, Chiranjib; Singh, Puneet Kumar; Shukla, Pratyoosh

    2016-03-01

    Exploring the efficiency of algae to produce remarkable products can be directly benefitted by studying its mechanism at systems level. Recent advents in biotechnology like flux balance analysis (FBA), genomics and in silico proteomics minimize the wet lab exertion. It is understood that FBA predicts the metabolic products, metabolic pathways and alternative pathway to maximize the desired product, and these are key components for microalgae bio-engineering. This review encompasses recent transgenesis techniques and metabolic engineering strategies applied to different microalgae for improving different traits. Further it also throws light on RNAi and riboswitch engineering based methods which may be advantageous for high throughput microalgal research. A valid and optimally designed microalga can be developed where every engineering strategies meet each other successfully and will definitely fulfill the market needs. It is also to be noted that Omics (viz. genetic and metabolic manipulation with bioinformatics) should be integrated to develop a strain which could prove to be a futuristic solution for sustainable development for energy. Copyright © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Multi-trait evolution of farmer varieties of bread wheat after cultivation in contrasting organic farming systems in Europe.

    Science.gov (United States)

    Dawson, J C; Serpolay, E; Giuliano, S; Schermann, N; Galic, N; Chable, V; Goldringer, I

    2012-03-01

    Because of the lack of varieties for organic agriculture, associations of organic farmers in several European countries have begun cultivating landraces and historic varieties, effectively practicing in situ conservation of agricultural biodiversity. To promote agrobiodiversity conservation, a special list for "conservation varieties" was implemented in 2008 by the EU because for any exchange and marketing of seeds in the EU, a variety must be registered in an official catalog. Our study aimed at improving knowledge on the phenotypic diversity and evolution of such varieties when cultivated on organic farms in Europe, in order to better define their specific characteristics and the implications for the registration process. We assessed multi-trait phenotypic evolution in eight European landraces and historic varieties of bread wheat and in two pureline variety checks, each grown by eight organic farmers over 2 years and then evaluated in a common garden experiment at an organic research farm. Measurements on each farmer's version of each variety included several standard evaluation criteria for assessing distinctness, uniformity and stability for variety registration. Significant phenotypic differentiation was found among farmers' versions of each variety. Some varieties showed considerable variation among versions while others showed fewer phenotypic changes, even in comparison to the two checks. Although farmers' variety would not satisfy uniformity or stability criteria as defined in the catalog evaluation requirements, each variety remained distinct when assessed using multivariate analysis. The amount of differentiation may be related to the initial genetic diversity within landraces and historic varieties.

  1. Assessment of long-term cultivated human precision-cut lung slices as an ex vivo system for evaluation of chronic cytotoxicity and functionality.

    Science.gov (United States)

    Neuhaus, Vanessa; Schaudien, Dirk; Golovina, Tatiana; Temann, Ulla-Angela; Thompson, Carolann; Lippmann, Torsten; Bersch, Claus; Pfennig, Olaf; Jonigk, Danny; Braubach, Peter; Fieguth, Hans-Gerd; Warnecke, Gregor; Yusibov, Vidadi; Sewald, Katherina; Braun, Armin

    2017-01-01

    Investigation of basic chronic inflammatory mechanisms and development of new therapeutics targeting the respiratory tract requires appropriate testing systems, including those to monitor long- persistence. Human precision-cut lung slices (PCLS) have been demonstrated to mimic the human respiratory tract and have potential of an alternative, ex-vivo system to replace or augment in-vitro testing and animal models. So far, most research on PCLS has been conducted for short cultivation periods (≤72 h), while analyses of slowly metabolized therapeutics require long-term survival of PCLS in culture. In the present study, we evaluated viability, physiology and structural integrity of PCLS cultured for up to 15 days. PCLS were cultured for 15 days and various parameters were assessed at different time points. Structural integrity and viability of cultured PCLS remained constant for 15 days. Moreover, bronchoconstriction was inducible over the whole period of cultivation, though with decreased sensitivity (EC 50 1d = 4 × 10 -8  M vs. EC 50 15d = 4 × 10 -6  M) and reduced maximum of initial airway area (1d = 0.5% vs. 15d = 18.7%). In contrast, even though still clearly inducible compared to medium control, LPS-induced TNF-α secretion decreased significantly from day 1 to day 15 of culture. Overall, though long-term cultivation of PCLS need further investigation for cytokine secretion, possibly on a cellular level, PCLS are feasible for bronchoconstriction studies and toxicity assays.

  2. Water-saving analysis on an effective water reuse system in biodiesel feedstock production based on Chlorella zofingiensis fed-batch cultivation.

    Science.gov (United States)

    Yang, Kang; Qin, Lei; Wang, Zhongming; Feng, Wei; Feng, Pingzhong; Zhu, Shunni; Xu, Jingliang; Yuan, Zhenhong

    2015-01-01

    The micralgae-based biofuel obtained from dairy wastewater (DWW) is considered a promising source of energy. However, this process consumes water due to the concentration of wastewater being normally too high for some micoralgae cultivation, and dilution is always needed. In this work, the cultivation of microalgae has been examined in non-recirculated water (NR) and recirculated water systems (R). The growth of Chlorella zofingiensis and the nutrient removal of DWW have been recorded. The comparison indicates the R had a little more advantage in biomass and lipid output (1.55, 0.22 g, respectively) than the NR (1.51, 0.20 g, respectively). However, the total chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN), and total phosphorus (TP) removals of the R were lower than those of the NR system during the culture. The highest removal of total COD, TKN, and TP were 85.05%, 93.64%, and 98.45%, respectively. Furthermore, no significant difference has been observed in the higher heating value and lipid content of the biomass of the R and NR. The results show the R can save 30% of the total water input during the culture. All above results indicate the R system has great potential in industry.

  3. Improving Former Shifted Cultivation Land Using Wetland Cultivation in Kapuas District, Central Kalimantan

    Directory of Open Access Journals (Sweden)

    Wahyudi Wahyudi

    2016-06-01

    Full Text Available Degraded forest area in Kalimantan could be caused by shifted cultivation activity that be conducted by local peoples in the surrounding forest areas. Efforts to improve the former shifted cultivation area (non productive land is developing the settled cultivation by use of irrigation system, better paddy seed, land processing, fertilizing, spraying pesticide, weeding, and better acces to the market.  Local peoples, especially in Kalimantan, has been depended their food on the shifted cultivation pattern since the long time ago.  This tradition could cause forest damage, forest fire, forest degradation, deforestation, and lose out of children education because they were following shifted cultivation activity although itsspace is very far from their home.  This research was aimed to improve former shifted cultivation lands using wetland cultivation in order to improve land productivity and to support food securityin the local community. This research was administratively located in Tanjung Rendan Village, Kapuas Hulu Sub-Ddistrict, Kapuas District, Central Kalimantan Province, Indonesia.  Data of rice yield from settled cultivation and shifted cultivation were got from 15 households that was taking by random at 2010 to 2011. Homogeneity test, analysis of variants, and least significant different (LSD test using SPSS 15.0 for Windows. Result of this research showed that     paddy yield at settled cultivation was significantly differentand better than shifted cultivation at 0.05 level. LSD test also indicated that all paddy yields from settled cultivation were significantly different compare to shifted cultivation at the 0.05 level.  The community in Tanjung Rendan Villages preferred settled cultivation than shifted cultivation, especially due to higher paddy production. Profit for settled cultivation was IDR10.95 million ha-1, meanwhile profit for shifted cultivation was just IDR 2.81 million ha-1 only.  Settled cultivation pattern could

  4. Utilization of carbon dioxide in industrial flue gases for the cultivation of microalga Chlorella sp.

    Science.gov (United States)

    Kao, Chien-Ya; Chen, Tsai-Yu; Chang, Yu-Bin; Chiu, Tzai-Wen; Lin, Hsiun-Yu; Chen, Chun-Da; Chang, Jo-Shu; Lin, Chih-Sheng

    2014-08-01

    The biomass and lipid productivity of Chlorella sp. MTF-15 cultivated using aeration with flue gases from a coke oven, hot stove or power plant in a steel plant of the China Steel Corporation in Taiwan were investigated. Using the flue gas from the coke oven, hot stove or power plant for cultivation, the microalgal strain obtained a maximum specific growth rate and lipid production of (0.827 d(-1), 0.688 g L(-1)), (0.762 d(-1), 0.961 g L(-1)), and (0.728 d(-1), 0.792 g L(-1)), respectively. This study demonstrated that Chlorella sp. MTF-15 could efficiently utilize the CO₂, NOX and SO₂ present in the different flue gases. The results also showed that the growth potential, lipid production and fatty acid composition of the microalgal strain were dependent on the composition of the flue gas and on the operating strategy deployed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Modeling the spatial distribution of crop cultivated areas at a large regional scale combining system dynamics and a modified Dyna-CLUE: A case from Iran

    Energy Technology Data Exchange (ETDEWEB)

    Mesgari, I.; Saeed Jabalameli, M.

    2017-07-01

    Agricultural land use pattern is affected by many factors at different scales and effects that are separated by time and space. This will lead to simulation models that optimize or project the cropping pattern changes and incorporate complexities in terms of details and dynamics. Combining System Dynamics (SD) and a modified Conversion of Land Use and its Effects (CLUE) modelling framework, this paper suggests a new dynamic approach for assessing the demand of different crops at country-level and for predicting the spatial distribution of cultivated areas at provincial scale. As example, a case study is presented for Iran, where we have simulated a scenario of future cropping pattern changes during 2015–2040.The results indicated a change in the spatial distribution of cultivated areas during the next years. An increase in the proportion of rice is expected in northern Iran, whereas the proportion of wheat is increasing in the mountainous western areas. Wheat and barley crops are expected to become dominant within the cropping system throughout the country regions.

  6. The influence of ripening stage and cultivation system on the total antioxidant activity and total phenolic compounds of yellow passion fruit pulp.

    Science.gov (United States)

    Macoris, Mariana S; De Marchi, Renata; Janzantti, Natália S; Monteiro, Magali

    2012-07-01

    This work aimed to investigate the influence of both ripening stage and cultivation system on the total phenolic compounds (TPC) and total antioxidant activity (TAA) of passion fruit pulp. TPC extraction was optimized using a 2³ central composed design. The variables were fruit pulp volume, methanol volume and extraction solution volume. TPC was determined using the Folin-Ciocalteu reaction, and TAA using the ABTS radical reaction. The conditions to extract TPC were 2 mL passion fruit pulp and 9 mL extraction solution containing 40% methanol:water (v/v). TPC values increased in the passion fruit pulp during ripening for both cultivation systems, ranging from 281.8 to 361.9 mg gallic acid L⁻¹ (P ≤ 0.05) for the organic pulp and from 291.0 to 338.6 mg gallic acid L⁻¹ (P ≤ 0.05) for the conventional pulp. TPC values increased during ripening for both organic and conventional passion fruit. The same was true for TAA values for conventional passion fruit. For organic passion fruit, however, TAA values were highest at the initial ripening stages. These results suggest that antioxidant compounds exert strong influence on the initial ripening stages for organic passion fruit, when TPC still did not reach its maximum level. Copyright © 2012 Society of Chemical Industry.

  7. Microalgal CO2 sequestering – Modeling microalgae production costs

    International Nuclear Information System (INIS)

    Bilanovic, Dragoljub; Holland, Mark; Armon, Robert

    2012-01-01

    Highlights: ► Microalgae production costs were modeled as a function of specific expenses. ► The effects of uncontrollable expenses/factors were incorporated into the model. ► Modeled microalgae production costs were in the range $102–1503 t −1 ha −1 y −1 . - Abstract: Microalgae CO 2 sequestering facilities might become an industrial reality if microalgae biomass could be produced at cost below $500.00 t −1 . We develop a model for estimation of total production costs of microalgae as a function of known production-specific expenses, and incorporate into the model the effects of uncontrollable factors which affect known production-specific expenses. Random fluctuations were intentionally incorporated into the model, consequently into generated cost/technology scenarios, because each and every logically interconnected equipment/operation that is used in design/construction/operation/maintenance of a production process is inevitably subject to random cost/price fluctuations which can neither be eliminated nor a priori controlled. A total of 152 costs/technology scenarios were evaluated to find 44 scenarios in which predicted total production costs of microalgae (PTPCM) was in the range $200–500 t −1 ha −1 y −1 . An additional 24 scenarios were found with PTCPM in the range of $102–200 t −1 ha −1 y −1 . These findings suggest that microalgae CO 2 sequestering and the production of commercial compounds from microalgal biomass can be economically viable venture even today when microalgae production technology is still far from its optimum.

  8. Manipulating nutrient composition of microalgal growth media to ...

    African Journals Online (AJOL)

    Biodiesel production from microalgae depends on the algal biomass and lipid content. Both biomass production and lipid accumulation are limited by several factors in which nutrients play a key role. We investigated the influences of micronutrients on biomass, and lipid content of Micractinium pusillum GU732425 cultivated ...

  9. Shifting Cultivation : Promoting Innovative Policy and Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    ... if improved and rationalized as an agroforestry system, has high potential for poverty ... with the livelihood issues of the cultivators and the health of the ecosystem, and assess the ... International Centre for Integrated Mountain Development.

  10. Harvesting Microalgal Biomass grown in Anaerobic Sewage Treatment Effluent by the Coagulation-Flocculation Method: Effect of pH

    Directory of Open Access Journals (Sweden)

    Servio Tulio Cassini

    2017-03-01

    Full Text Available ABSTRACT Harvesting is a critical step in microalgal biomass production process for many reasons. Among the existing techniques available for harvesting and dewatering microalgal biomass, recovery from aqueous medium by coagulation-flocculation has been the most economically viable process, althoughit is highly dependent on pH. This study aims to assess alternative coagulants compared to the standard coagulant aluminum sulfate for microalgal biomass recovery from anaerobic effluent of domestic sewage treatment. The effluent quality was also analyzed after biomass recovery. Coagulants represented by modified tannin, cationic starch and aluminum sulfate recovered more than 90% of algae biomass, at concentrations greater than 80 mg/L, in the pH range 7-10. Cationic starch promoted higher microalgal biomass recovery with a wider pH range. Powdered seeds of Moringa oleifera and Hibiscus esculentus(okra gum promoted biomass removal of 50%, only in the acidic range of pH. After sedimentation of the microalgal biomass, the effluents showed a removal of >80% for phosphorus and nitrogen values and >50% for BOD and COD when using aluminum sulfate, cationic starch and modified tannin as coagulants. Natural organic coagulants in a wide pH range can replace aluminum sulfate, a reference coagulant in microalgal biomass recovery, without decreasing microalgal biomass harvesting efficiency and the quality of the final effluent.

  11. Hydroponic cultivation of Oncidium baueri

    Directory of Open Access Journals (Sweden)

    Daniele Brandstetter Rodrigues

    2017-08-01

    Full Text Available In Brazil, orchid cultivation has been increasing steadily over the last few years and contributing significantly to the economy. It has been reported that several vegetable crops and ornamentals have been successfully grown by soilless cultivation. The orchid Oncidium baueri Lindl. is grown on pot substrates. Nevertheless, hydroponics is an excellent alternative, especially for the production of cut flowers and bare root plants. The objective of this study was to evaluate the development of Oncidium baueri on two soilless systems: (a pots containing Amafibra® coconut fiber, carbonized rice husk, and pine bark (1:1:1 irrigated with nutrient solution every 15 d; and (b a nutrient film technique (NFT hydroponic system irrigated with nutrient solution daily. Shoot height, pseudobulb diameter, and number of sprouts were evaluated monthly. The number of flowering plants, number of flowers, dry mass of shoots, and dry mass of roots were evaluated 11 months after onset of experiment. The pot cultivation system yielded more flowers and higher values for all vegetative parameters than the NFT hydroponic system.

  12. Similarity microalgal epiphyte composition on seagrass of Enhalus acoroides and Thalasia hemprichii from different waters

    Science.gov (United States)

    Hartati, R.; Zainuri, M.; Ambariyanto, A.; Widianingsih; Trianto, A.; Mahendrajaya, R. T.

    2018-03-01

    The epiphytes are all autotrophic organisms that are permanently attached to rhizomes, roots, and leaves of seagrasses. The epiphyte is an important primary producer for the seagrass ecosystem and contributes significantly to the food chain. This study aims to identify the composition of microepiphyte algae on Enhalus acoroides and Thalassia hemprichii and their similarity levels of both compositions. The 20 leaves samples of E. acoroides and T. hemprichii were observed. The epiphytic microalgae which found on the surface of the seagrass leaves were scrapped, collected in a bottle sample, and fixed with 70 % alcohol and identified into genera. The relation of epiphytic microalgal genera to the location and species of seagrass was analyzed using similarity analysis. The Chrysophyta, Cyanophyta, and Chlorophyta epiphytic microalgal were found. There were similarity variations of the microalgal epiphyte in seagrass of E. acoroides and T. hemprichii and seagrass habitat sites. Morphology and seagrass life affects the abundance and diversity of the epiphytic microalgal attached to the seagrass and it may be associated with the epiphytic lifetime in the seagrass.

  13. Benthic microalgal production in the Arctic: Applied methods and status of the current database

    DEFF Research Database (Denmark)

    Glud, Ronnie Nøhr; Woelfel, Jana; Karsten, Ulf

    2009-01-01

    The current database on benthic microalgal production in Arctic waters comprises 10 peer-reviewed and three unpublished studies. Here, we compile and discuss these datasets, along with the applied measurement approaches used. The latter is essential for robust comparative analysis and to clarify ...

  14. A comparative study: the impact of different lipid extraction methods on current microalgal lipid research

    Science.gov (United States)

    2014-01-01

    Microalgae cells have the potential to rapidly accumulate lipids, such as triacylglycerides that contain fatty acids important for high value fatty acids (e.g., EPA and DHA) and/or biodiesel production. However, lipid extraction methods for microalgae cells are not well established, and there is currently no standard extraction method for the determination of the fatty acid content of microalgae. This has caused a few problems in microlagal biofuel research due to the bias derived from different extraction methods. Therefore, this study used several extraction methods for fatty acid analysis on marine microalga Tetraselmis sp. M8, aiming to assess the potential impact of different extractions on current microalgal lipid research. These methods included classical Bligh & Dyer lipid extraction, two other chemical extractions using different solvents and sonication, direct saponification and supercritical CO2 extraction. Soxhlet-based extraction was used to weigh out the importance of solvent polarity in the algal oil extraction. Coupled with GC/MS, a Thermogravimetric Analyser was used to improve the quantification of microalgal lipid extractions. Among these extractions, significant differences were observed in both, extract yield and fatty acid composition. The supercritical extraction technique stood out most for effective extraction of microalgal lipids, especially for long chain unsaturated fatty acids. The results highlight the necessity for comparative analyses of microalgae fatty acids and careful choice and validation of analytical methodology in microalgal lipid research. PMID:24456581

  15. Advances in photobioreactors for intensive microalgal production: configurations, operating strategies and applications

    NARCIS (Netherlands)

    Olivieri, G.; Salatino, P.; Marzocchella, A.

    2014-01-01

    Over the past ten years a great deal of literature has focused on the biotechnological potential of microalgal commercial applications, mainly in the field of biofuel production. However, the biofuel production is not yet competitive, mainly due to the incidence of the photobioreactor technology on

  16. Controls on microalgal community structures in cryoconite holes upon high-Arctic glaciers, Svalbard

    Czech Academy of Sciences Publication Activity Database

    Vonnahme, T.R.; Devetter, Miloslav; Žárský, J.D.; Šabacká, M.; Elster, Josef

    2016-01-01

    Roč. 13, č. 3 (2016), s. 659-674 ISSN 1726-4170 Institutional support: RVO:60077344 ; RVO:67985939 Keywords : microalgal communities * cryoconite holes * high-Arctic glaciers * Svalbard Subject RIV: EH - Ecology, Behaviour Impact factor: 3.851, year: 2016

  17. Phosphorus removal using a microalgal biofilm in a new biofilm photobioreactor for tertiary wastewater treatment

    Czech Academy of Sciences Publication Activity Database

    Sukačová, Kateřina; Trtílek, M.; Rataj, Tomáš

    2015-01-01

    Roč. 75, mar (2015), s. 55-63 ISSN 0043-1354 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073 Institutional support: RVO:67179843 Keywords : microalgal biofilm * phosphorus removal * wastewater treatment Subject RIV: EH - Ecology, Behaviour Impact factor: 5.991, year: 2015

  18. Isolation and cultivation of microalgae select for low growth rate and tolerance to high pH

    DEFF Research Database (Denmark)

    Berge, Terje; Daugbjerg, Niels; Hansen, Per Juel

    2012-01-01

    Harmful microalgal blooms or red tides are often associated with high levels of pH. Similarly, species and strains of microalgae cultivated in the laboratory with enriched media experience recurrent events of high pH between dilutions with fresh medium. To study the potential for laboratory...... of upper pH tolerance limits were higher in the younger (20 years). These results suggest selection of strains best adapted to tolerate or postpone/avoid events of high pH in the laboratory. Our data have implications for experimental studies of pH response and reaction norms in general of microalgae...

  19. Dynamics of Short-Term Phosphorus Uptake by Intact Mycorrhizal and Non-mycorrhizal Maize Plants Grown in a Circulatory Semi-Hydroponic Cultivation System.

    Science.gov (United States)

    Garcés-Ruiz, Mónica; Calonne-Salmon, Maryline; Plouznikoff, Katia; Misson, Coralie; Navarrete-Mier, Micaela; Cranenbrouck, Sylvie; Declerck, Stéphane

    2017-01-01

    A non-destructive cultivation system was developed to study the dynamics of phosphorus (Pi) uptake by mycorrhizal and non-mycorrhizal maize plantlets. The system consisted of a plant container connected via silicon tubes to a glass bottle containing a nutrient solution supplemented with Pi. The nutrient solution is pumped with a peristaltic pump to the upper part of the container via the silicon tubes and the solution percolate through the plantlet container back into the glass bottle. Pi is sampled from the glass bottle at regular intervals and concentration evaluated. Maize plantlets were colonized by the AMF Rhizophagus irregularis MUCL 41833 and Pi uptake quantified at fixed intervals (9, 21, and 42 h) from the depletion of the Pi in the nutrient solution flowing through the plantlets containers. Plants and fungus grew well in the perlite substrate. The concentration of Pi in the bottles followed an almost linear decrease over time, demonstrating a depletion of Pi in the circulating solution and a concomitant uptake/immobilization by the plantlet-AMF associates in the containers. The Pi uptake rate was significantly increased in the AMF-colonized plantlets (at 9 and 21 h) as compared to non-colonized plantlets, although no correlation was noticed with plant growth or P accumulation in shoots. The circulatory semi-hydroponic cultivation system developed was adequate for measuring Pi depletion in a nutrient solution and by corollary Pi uptake/immobilization by the plant-AMF associates. The measurements were non-destructive so that the time course of Pi uptake could be monitored without disturbing the growth of the plant and its fungal associate. The system further opens the door to study the dynamics of other micro and macro-nutrients as well as their uptake under stressed growth conditions such as salinity, pollution by hydrocarbon contaminants or potential toxic elements.

  20. Dynamics of Short-Term Phosphorus Uptake by Intact Mycorrhizal and Non-mycorrhizal Maize Plants Grown in a Circulatory Semi-Hydroponic Cultivation System

    Directory of Open Access Journals (Sweden)

    Mónica Garcés-Ruiz

    2017-08-01

    Full Text Available A non-destructive cultivation system was developed to study the dynamics of phosphorus (Pi uptake by mycorrhizal and non-mycorrhizal maize plantlets. The system consisted of a plant container connected via silicon tubes to a glass bottle containing a nutrient solution supplemented with Pi. The nutrient solution is pumped with a peristaltic pump to the upper part of the container via the silicon tubes and the solution percolate through the plantlet container back into the glass bottle. Pi is sampled from the glass bottle at regular intervals and concentration evaluated. Maize plantlets were colonized by the AMF Rhizophagus irregularis MUCL 41833 and Pi uptake quantified at fixed intervals (9, 21, and 42 h from the depletion of the Pi in the nutrient solution flowing through the plantlets containers. Plants and fungus grew well in the perlite substrate. The concentration of Pi in the bottles followed an almost linear decrease over time, demonstrating a depletion of Pi in the circulating solution and a concomitant uptake/immobilization by the plantlet-AMF associates in the containers. The Pi uptake rate was significantly increased in the AMF-colonized plantlets (at 9 and 21 h as compared to non-colonized plantlets, although no correlation was noticed with plant growth or P accumulation in shoots. The circulatory semi-hydroponic cultivation system developed was adequate for measuring Pi depletion in a nutrient solution and by corollary Pi uptake/immobilization by the plant-AMF associates. The measurements were non-destructive so that the time course of Pi uptake could be monitored without disturbing the growth of the plant and its fungal associate. The system further opens the door to study the dynamics of other micro and macro-nutrients as well as their uptake under stressed growth conditions such as salinity, pollution by hydrocarbon contaminants or potential toxic elements.

  1. [Growth and biochemical composition of thalassiosira pseudonana (Thalassiosirales: Thalassiosiraceae) cultivated in semicontinuous system at different culture media and irradiances].

    Science.gov (United States)

    Vásquez-Suárez, Aleikar; Guevara, Miguel; González, Mayelys; Cortez, Roraysi; Arredondo-Vega, Bertha

    2013-09-01

    Thalassiosira pseudonana is a marine Bacillariophyta commonly used as live feed in mariculture. The growth rate and biochemical composition of microalgae are highly influenced by environmental factors such as, irradiance and nutrient availability. The aim of this study was to investigate the influence of three irradiances (60, 120 and 180 microE/m2.s) and two culture media (Algal and Humus) on growth and biochemical composition of this diatom. The microalga was grown semicontinuously at a daily renewal rate of fresh media of 30%, 37 per thousand salinity, 25 +/- 1 degree C and constant aeration (200 mL/min). The cell densities (cel/mL) and contents of protein, lipid, carbohydrate, chlorophyll a, total carotenoids, and fatty acids, showed significant differences (p media, the fatty acids unsaturation degree was lower with increasing irradiance, being eicosapentaenoic acid, 20:5 n-3 (EPA) most represented (6.20%) in Algal medium at 60 microE/m2.s. This strain of T. pseudonana showed multiple physiological responses to changes in culture conditions, and may be cultivated with an alternative medium, which reduced the operating costs and allowed a high nutritional biomass production value for animals under culture.

  2. Modeling the transformation of atmospheric CO2 into microalgal biomass.

    Science.gov (United States)

    Hasan, Mohammed Fahad; Vogt, Frank

    2017-10-23

    Marine phytoplankton acts as a considerable sink of atmospheric CO 2 as it sequesters large quantities of this greenhouse gas for biomass production. To assess microalgae's counterbalancing of global warming, the quantities of CO 2 they fix need to be determined. For this task, it is mandatory to understand which environmental and physiological parameters govern this transformation from atmospheric CO 2 to microalgal biomass. However, experimental analyses are challenging as it has been found that the chemical environment has a major impact on the physiological properties of the microalgae cells (diameter typ. 5-20 μm). Moreover, the cells can only chemically interact with their immediate vicinity and thus compound sequestration needs to be studied on a microscopic spatial scale. Due to these reasons, computer simulations are a more promising approach than the experimental studies. Modeling software has been developed that describes the dissolution of atmospheric CO 2 into oceans followed by the formation of HCO 3 - which is then transported to individual microalgae cells. The second portion of this model describes the competition of different cell species for this HCO 3 - , a nutrient, as well as its uptake and utilization for cell production. Two microalgae species, i.e. Dunaliella salina and Nannochloropsis oculata, were cultured individually and in a competition situation under different atmospheric CO 2 conditions. It is shown that this novel model's predictions of biomass production are in very good agreement with the experimental flow cytometry results. After model validation, it has been applied to long-term prediction of phytoplankton generation. These investigations were motivated by the question whether or not cell production slows down as cultures grow. This is of relevance as a reduced cell production rate means that the increase in a culture's CO 2 -sinking capacity slows down as well. One implication resulting from this is that an increase in

  3. Life cycle assessment of coupling household biogas production to agricultural industry: A case study of biogas-linked persimmon cultivation and processing system

    International Nuclear Information System (INIS)

    Chen, Bin; Chen, Shaoqing

    2013-01-01

    Biogas plant construction has been boosted in rural China not only due to the immediate merit from biogas production but also the succeeding benefit from by-product utilization in agro-industry, both of which are significant strategies to address energy shortage and global warming issues. However, little work has been done to evaluate the coupling of biogas projects to traditional agrosystems from a life-cycle perspective, which is most important in process and system optimization in different senses. By taking persimmon cultivation and processing with supports from a household biogas plant as a case study, this study conducts a life cycle assessment of coupling biogas production to agro-industry in terms of energy, environmental and economic performance. The results suggest that each production stage following the biogas/digestate utilization chain (biogas operation-persimmon cultivation-product processing) is beneficial across all three aspects. However, a tradeoff only exists in utilizing digestate as top-dressing and employing biogas utilization as engine fuel, while biogas application in fresh-keeping and digestate reuse as base fertilizer fails to increase either energy production or greenhouse gas mitigation. The coupled system can be hopefully optimized through increasing fermentation efficiency and joint operation of biogas digesters. -- Highlights: •Biogas/digestate utilization is overall beneficial in all production stages. •Each bioresource application may not be profitable in all respects. •Tradeoffs in using biogas and digestate vary among different utilization ways. •Multi-user operation and fermentation efficiency elevation optimize system

  4. Cultivation and characterization of Candidatus Nitrosocosmicus exaquare, an ammonia-oxidizing archaeon from a municipal wastewater treatment system.

    Science.gov (United States)

    Sauder, Laura A; Albertsen, Mads; Engel, Katja; Schwarz, Jasmin; Nielsen, Per H; Wagner, Michael; Neufeld, Josh D

    2017-05-01

    Thaumarchaeota have been detected in several industrial and municipal wastewater treatment plants (WWTPs), despite the fact that ammonia-oxidizing archaea (AOA) are thought to be adapted to low ammonia environments. However, the activity, physiology and metabolism of WWTP-associated AOA remain poorly understood. We report the cultivation and complete genome sequence of Candidatus Nitrosocosmicus exaquare, a novel AOA representative from a municipal WWTP in Guelph, Ontario (Canada). In enrichment culture, Ca. N. exaquare oxidizes ammonia to nitrite stoichiometrically, is mesophilic, and tolerates at least 15 mm of ammonium chloride or sodium nitrite. Microautoradiography (MAR) for enrichment cultures demonstrates that Ca. N. exaquare assimilates bicarbonate in association with ammonia oxidation. However, despite using inorganic carbon, the ammonia-oxidizing activity of Ca. N. exaquare is greatly stimulated in enrichment culture by the addition of organic compounds, especially malate and succinate. Ca. N. exaquare cells are coccoid with a diameter of ~1-2 μm. Phylogenetically, Ca. N. exaquare belongs to the Nitrososphaera sister cluster within the Group I.1b Thaumarchaeota, a lineage which includes most other reported AOA sequences from municipal and industrial WWTPs. The 2.99 Mbp genome of Ca. N. exaquare encodes pathways for ammonia oxidation, bicarbonate fixation, and urea transport and breakdown. In addition, this genome encodes several key genes for dealing with oxidative stress, including peroxidase and catalase. Incubations of WWTP biofilm demonstrate partial inhibition of ammonia-oxidizing activity by 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (PTIO), suggesting that Ca. N. exaquare-like AOA may contribute to nitrification in situ. However, CARD-FISH-MAR showed no incorporation of bicarbonate by detected Thaumarchaeaota, suggesting that detected AOA may incorporate non-bicarbonate carbon sources or rely on an alternative and yet unknown

  5. Microalgal Metabolic Network Model Refinement through High-Throughput Functional Metabolic Profiling

    International Nuclear Information System (INIS)

    Chaiboonchoe, Amphun; Dohai, Bushra Saeed; Cai, Hong; Nelson, David R.; Jijakli, Kenan; Salehi-Ashtiani, Kourosh

    2014-01-01

    Metabolic modeling provides the means to define metabolic processes at a systems level; however, genome-scale metabolic models often remain incomplete in their description of metabolic networks and may include reactions that are experimentally unverified. This shortcoming is exacerbated in reconstructed models of newly isolated algal species, as there may be little to no biochemical evidence available for the metabolism of such isolates. The phenotype microarray (PM) technology (Biolog, Hayward, CA, USA) provides an efficient, high-throughput method to functionally define cellular metabolic activities in response to a large array of entry metabolites. The platform can experimentally verify many of the unverified reactions in a network model as well as identify missing or new reactions in the reconstructed metabolic model. The PM technology has been used for metabolic phenotyping of non-photosynthetic bacteria and fungi, but it has not been reported for the phenotyping of microalgae. Here, we introduce the use of PM assays in a systematic way to the study of microalgae, applying it specifically to the green microalgal model species Chlamydomonas reinhardtii. The results obtained in this study validate a number of existing annotated metabolic reactions and identify a number of novel and unexpected metabolites. The obtained information was used to expand and refine the existing COBRA-based C. reinhardtii metabolic network model iRC1080. Over 254 reactions were added to the network, and the effects of these additions on flux distribution within the network are described. The novel reactions include the support of metabolism by a number of d-amino acids, l-dipeptides, and l-tripeptides as nitrogen sources, as well as support of cellular respiration by cysteamine-S-phosphate as a phosphorus source. The protocol developed here can be used as a foundation to functionally profile other microalgae such as known microalgae mutants and novel isolates.

  6. Microalgal Metabolic Network Model Refinement through High-Throughput Functional Metabolic Profiling

    Energy Technology Data Exchange (ETDEWEB)

    Chaiboonchoe, Amphun; Dohai, Bushra Saeed; Cai, Hong; Nelson, David R. [Division of Science and Math, New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Center for Genomics and Systems Biology (CGSB), New York University Abu Dhabi Institute, Abu Dhabi (United Arab Emirates); Jijakli, Kenan [Division of Science and Math, New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Center for Genomics and Systems Biology (CGSB), New York University Abu Dhabi Institute, Abu Dhabi (United Arab Emirates); Engineering Division, Biofinery, Manhattan, KS (United States); Salehi-Ashtiani, Kourosh, E-mail: ksa3@nyu.edu [Division of Science and Math, New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Center for Genomics and Systems Biology (CGSB), New York University Abu Dhabi Institute, Abu Dhabi (United Arab Emirates)

    2014-12-10

    Metabolic modeling provides the means to define metabolic processes at a systems level; however, genome-scale metabolic models often remain incomplete in their description of metabolic networks and may include reactions that are experimentally unverified. This shortcoming is exacerbated in reconstructed models of newly isolated algal species, as there may be little to no biochemical evidence available for the metabolism of such isolates. The phenotype microarray (PM) technology (Biolog, Hayward, CA, USA) provides an efficient, high-throughput method to functionally define cellular metabolic activities in response to a large array of entry metabolites. The platform can experimentally verify many of the unverified reactions in a network model as well as identify missing or new reactions in the reconstructed metabolic model. The PM technology has been used for metabolic phenotyping of non-photosynthetic bacteria and fungi, but it has not been reported for the phenotyping of microalgae. Here, we introduce the use of PM assays in a systematic way to the study of microalgae, applying it specifically to the green microalgal model species Chlamydomonas reinhardtii. The results obtained in this study validate a number of existing annotated metabolic reactions and identify a number of novel and unexpected metabolites. The obtained information was used to expand and refine the existing COBRA-based C. reinhardtii metabolic network model iRC1080. Over 254 reactions were added to the network, and the effects of these additions on flux distribution within the network are described. The novel reactions include the support of metabolism by a number of d-amino acids, l-dipeptides, and l-tripeptides as nitrogen sources, as well as support of cellular respiration by cysteamine-S-phosphate as a phosphorus source. The protocol developed here can be used as a foundation to functionally profile other microalgae such as known microalgae mutants and novel isolates.

  7. Exploring the Cultivable Ectocarpus Microbiome.

    Science.gov (United States)

    KleinJan, Hetty; Jeanthon, Christian; Boyen, Catherine; Dittami, Simon M

    2017-01-01

    Coastal areas form the major habitat of brown macroalgae, photosynthetic multicellular eukaryotes that have great ecological value and industrial potential. Macroalgal growth, development, and physiology are influenced by the microbial community they accommodate. Studying the algal microbiome should thus increase our fundamental understanding of algal biology and may help to improve culturing efforts. Currently, a freshwater strain of the brown macroalga Ectocarpus subulatus is being developed as a model organism for brown macroalgal physiology and algal microbiome studies. It can grow in high and low salinities depending on which microbes it hosts. However, the molecular mechanisms involved in this process are still unclear. Cultivation of Ectocarpus -associated bacteria is the first step toward the development of a model system for in vitro functional studies of brown macroalgal-bacterial interactions during abiotic stress. The main aim of the present study is thus to provide an extensive collection of cultivable E . subulatus -associated bacteria. To meet the variety of metabolic demands of Ectocarpus -associated bacteria, several isolation techniques were applied, i.e., direct plating and dilution-to-extinction cultivation techniques, each with chemically defined and undefined bacterial growth media. Algal tissue and algal growth media were directly used as inoculum, or they were pretreated with antibiotics, by filtration, or by digestion of algal cell walls. In total, 388 isolates were identified falling into 33 genera (46 distinct strains), of which Halomonas ( Gammaproteobacteria ), Bosea ( Alphaproteobacteria ), and Limnobacter ( Betaproteobacteria ) were the most abundant. Comparisons with 16S rRNA gene metabarcoding data showed that culturability in this study was remarkably high (∼50%), although several cultivable strains were not detected or only present in extremely low abundance in the libraries. These undetected bacteria could be considered as part

  8. Exploring the Cultivable Ectocarpus Microbiome

    Directory of Open Access Journals (Sweden)

    Hetty KleinJan

    2017-12-01

    Full Text Available Coastal areas form the major habitat of brown macroalgae, photosynthetic multicellular eukaryotes that have great ecological value and industrial potential. Macroalgal growth, development, and physiology are influenced by the microbial community they accommodate. Studying the algal microbiome should thus increase our fundamental understanding of algal biology and may help to improve culturing efforts. Currently, a freshwater strain of the brown macroalga Ectocarpus subulatus is being developed as a model organism for brown macroalgal physiology and algal microbiome studies. It can grow in high and low salinities depending on which microbes it hosts. However, the molecular mechanisms involved in this process are still unclear. Cultivation of Ectocarpus-associated bacteria is the first step toward the development of a model system for in vitro functional studies of brown macroalgal–bacterial interactions during abiotic stress. The main aim of the present study is thus to provide an extensive collection of cultivable E. subulatus-associated bacteria. To meet the variety of metabolic demands of Ectocarpus-associated bacteria, several isolation techniques were applied, i.e., direct plating and dilution-to-extinction cultivation techniques, each with chemically defined and undefined bacterial growth media. Algal tissue and algal growth media were directly used as inoculum, or they were pretreated with antibiotics, by filtration, or by digestion of algal cell walls. In total, 388 isolates were identified falling into 33 genera (46 distinct strains, of which Halomonas (Gammaproteobacteria, Bosea (Alphaproteobacteria, and Limnobacter (Betaproteobacteria were the most abundant. Comparisons with 16S rRNA gene metabarcoding data showed that culturability in this study was remarkably high (∼50%, although several cultivable strains were not detected or only present in extremely low abundance in the libraries. These undetected bacteria could be considered

  9. Ultrasonic disintegration of microalgal biomass and consequent improvement of bioaccessibility/bioavailability in microbial fermentation.

    Science.gov (United States)

    Jeon, Byong-Hun; Choi, Jeong-A; Kim, Hyun-Chul; Hwang, Jae-Hoon; Abou-Shanab, Reda Ai; Dempsey, Brian A; Regan, John M; Kim, Jung Rae

    2013-01-01

    Microalgal biomass contains a high level of carbohydrates which can be biochemically converted to biofuels using state-of-the-art strategies that are almost always needed to employ a robust pretreatment on the biomass for enhanced energy production. In this study, we used an ultrasonic pretreatment to convert microalgal biomass (Scenedesmus obliquus YSW15) into feasible feedstock for microbial fermentation to produce ethanol and hydrogen. The effect of sonication condition was quantitatively evaluated with emphases on the characterization of carbohydrate components in microalgal suspension and on subsequent production of fermentative bioenergy. Scenedesmus obliquus YSW15 was isolated from the effluent of a municipal wastewater treatment plant. The sonication durations of 0, 10, 15, and 60 min were examined under different temperatures at a fixed frequency and acoustic power resulted in morphologically different states of microalgal biomass lysis. Fermentation was performed to evaluate the bioenergy production from the non-sonicated and sonicated algal biomasses after pretreatment stage under both mesophilic (35°C) and thermophilic (55°C) conditions. A 15 min sonication treatment significantly increased the concentration of dissolved carbohydrates (0.12 g g(-1)), which resulted in an increase of hydrogen/ethanol production through microbial fermentation. The bioconvertibility of microalgal biomass sonicated for 15 min or longer was comparable to starch as a control, indicating a high feasibility of using microalgae for fermentative bioenergy production. Increasing the sonication duration resulted in increases in both algal surface hydrophilicity and electrostatic repulsion among algal debris dispersed in aqueous solution. Scanning electron microscope images supported that ruptured algal cell allowed fermentative bacteria to access the inner space of the cell, evidencing an enhanced bioaccessibility. Sonication for 15 min was the best for fermentative

  10. Cultivation and harvesting of microalgae in photobioreactor for biodiesel production and simultaneous nutrient removal

    International Nuclear Information System (INIS)

    Yang, Il-Seung; Salama, El-Sayed; Kim, Jong-Oh; Govindwar, Sanjay P.; Kurade, Mayur B.; Lee, Minsun; Roh, Hyun-Seog; Jeon, Byong-Hun

    2016-01-01

    Highlights: • Wastewater treatment with algal biomass production was evaluated in a bench-scale. • C. vulgaris and S. obliquus showed μ_o_p_t values of 1.39 and 1.41 day"−"1, respectively. • Complete removal (>99%) of TN and TP by both algal strains was observed. • Harvesting efficiency of M. oleifera was 81% for C. vulgaris and 92% for S. obliquus. - Abstract: Microalgae, Chlorella vulgaris and Scenedesmus obliquus were cultivated in a small scale vertical flat-plate photobioreactor (PBR) supplemented with municipal wastewater in order to achieve simultaneous wastewater treatment and biomass production for biofuel generation. Microalgal growth and nutrient removal including total nitrogen (TN), total phosphorus (TP), total inorganic carbon (TIC) and trace elements (Ca"2"+, Na"+, Mg"2"+ and Zn"2"+) were monitored during microalgae cultivation. C. vulgaris and S. obliquus showed optimal specific growth rates (μ_o_p_t) of 1.39 and 1.41 day"−"1, respectively, and the TN and TP were completely removed (>99%) from the wastewater within 8 days. Microalgal biomass in the PBR was harvested using a natural flocculant produced from Moringa oleifera seeds. The harvesting efficiency of M. oleifera was 81% for C. vulgaris and 92% for S. obliquus. The amounts of saturated, mono-unsaturated, and poly-unsaturated fatty acids in the harvested biomass accounted for 18.66%, 71.61% and 9.75% for C. vulgaris and 28.67%, 57.14% and 11.15% for S. obliquus, respectively. The accumulated fatty acids were suitable to produce high quality biodiesel with characteristics equivalent to crop seeds oil-derived biodiesel. This study demonstrates the potential of microalgae-based biodiesel production through the coupling of advanced wastewater treatment with microalgae cultivation for low-cost biomass production in a PBR.

  11. Conveyor Cultivation of the Halophytic Plant Salicornia europaea for the Recycling of NaCl from Human Liquid Waste in a Biological Life Support System.

    Science.gov (United States)

    Balnokin, Yurii; Myasoedov, Nikolay; Popova, Larissa; Tikhomirov, Alexander A.; Ushakova, Sofya; Tikhomirova, Natalia; Lasseur, Christophe; Gros, Jean-Bernard

    One problem in designing bioregenerative life support systems (BLSS) is developing technolo-gies to include human liquid and solid waste in intrasystem recycling. A specific task is recycling of NaCl excreted in urine by humans. We showed recently that this could be achieved through inclusion of the salt accumulating halophyte Salicornia europaea in the autotrophic compart-ment of the BLSS (Balnokin et al., ASR, 2010, in press). A model of NaCl circulation in BLSS with inclusion of S. europaea was based on the NaCl turnover in the human -urine -nutrient solution -S. europaea -human cycle. Mineralized urine was used as a basis for preparation of a nutrient solution for the halophyte cultivation. The shoots of the halophyte cultivated in the mineralized urine and containing NaCl could to be used by the BLSS inhabitants in their diets. In this report we describe cultivation of S. europaea which allows turnover of NaCl and produces daily shoot biomass containing Na+ and Cl- in quantities approximately equal to those excreted in daily human urine. The plants were grown in water culture in a climatic chamber under controlled conditions. A solution simulating mineralized urine (SSMU) was used as a basis for preparation of a nutri-ent solution for S. europaea cultivation. For continuous biomass production, seedlings of S. europaea, germinated preliminary in moist sand, were being transferred to the nutrient solu-tion at regular intervals (every two days). Duration of the conveyor operation was 112 days. During the first 56 days, the seedlings were being planted in SSMU diluted by a factor of 1.5 (2/3 SSMU). The same solution was introduced into the growth vessels as volumes of growth medium decreased due to plant transpiration. Starting from the 56th day as conveyor operation was initiated, the plants were being harvested every two days; the solutions from the discharged vessels were mixed with the fresh SSMU and the mixture was introduced into all other growth vessels of

  12. Utilization of Microalgal Biofractions for Bioethanol, Higher Alcohols, and Biodiesel Production: A Review

    Directory of Open Access Journals (Sweden)

    Marwa M. El-Dalatony

    2017-12-01

    Full Text Available Biomass is a crucial energy resource used for the generation of electricity and transportation fuels. Microalgae exhibit a high content of biocomponents which makes them a potential feedstock for the generation of ecofriendly biofuels. Biofuels derived from microalgae are suitable carbon-neutral replacements for petroleum. Fermentation is the major process for metabolic conversion of microalgal biocompounds into biofuels such as bioethanol and higher alcohols. In this review, we explored the use of all three major biocomponents of microalgal biomass including carbohydrates, proteins, and lipids for maximum biofuel generation. Application of several pretreatment methods for enhancement the bioavailability of substrates (simple sugar, amino acid, and fatty acid was discussed. This review goes one step further to discuss how to direct these biocomponents for the generation of various biofuels (bioethanol, higher alcohol, and biodiesel through fermentation and transesterification processes. Such an approach would result in the maximum utilization of biomasses for economically feasible biofuel production.

  13. Cultivating the Deep Subsurface Microbiome

    Science.gov (United States)

    Casar, C. P.; Osburn, M. R.; Flynn, T. M.; Masterson, A.; Kruger, B.

    2017-12-01

    Subterranean ecosystems are poorly understood because many microbes detected in metagenomic surveys are only distantly related to characterized isolates. Cultivating microorganisms from the deep subsurface is challenging due to its inaccessibility and potential for contamination. The Deep Mine Microbial Observatory (DeMMO) in Lead, SD however, offers access to deep microbial life via pristine fracture fluids in bedrock to a depth of 1478 m. The metabolic landscape of DeMMO was previously characterized via thermodynamic modeling coupled with genomic data, illustrating the potential for microbial inhabitants of DeMMO to utilize mineral substrates as energy sources. Here, we employ field and lab based cultivation approaches with pure minerals to link phylogeny to metabolism at DeMMO. Fracture fluids were directed through reactors filled with Fe3O4, Fe2O3, FeS2, MnO2, and FeCO3 at two sites (610 m and 1478 m) for 2 months prior to harvesting for subsequent analyses. We examined mineralogical, geochemical, and microbiological composition of the reactors via DNA sequencing, microscopy, lipid biomarker characterization, and bulk C and N isotope ratios to determine the influence of mineralogy on biofilm community development. Pre-characterized mineral chips were imaged via SEM to assay microbial growth; preliminary results suggest MnO2, Fe3O4, and Fe2O3 were most conducive to colonization. Solid materials from reactors were used as inoculum for batch cultivation experiments. Media designed to mimic fracture fluid chemistry was supplemented with mineral substrates targeting metal reducers. DNA sequences and microscopy of iron oxide-rich biofilms and fracture fluids suggest iron oxidation is a major energy source at redox transition zones where anaerobic fluids meet more oxidizing conditions. We utilized these biofilms and fluids as inoculum in gradient cultivation experiments targeting microaerophilic iron oxidizers. Cultivation of microbes endemic to DeMMO, a system

  14. A Spiral Step-by-Step Educational Method for Cultivating Competent Embedded System Engineers to Meet Industry Demands

    Science.gov (United States)

    Jing,Lei; Cheng, Zixue; Wang, Junbo; Zhou, Yinghui

    2011-01-01

    Embedded system technologies are undergoing dramatic change. Competent embedded system engineers are becoming a scarce resource in the industry. Given this, universities should revise their specialist education to meet industry demands. In this paper, a spirally tight-coupled step-by-step educational method, based on an analysis of industry…

  15. Quantitative assessment of microalgae biomass and lipid stability post cultivation

    Directory of Open Access Journals (Sweden)

    Katerine eNapan

    2015-04-01

    Full Text Available Processing of microalgal biomass to biofuels and other products requires the removal of the culture from a well-controlled growth system to a containment or preprocessing step at non-ideal growth conditions, such as darkness, minimal gas exchange, and fluctuating temperatures. The conditions and the length of time between harvest and processing will impact microalgal metabolism resulting in biomass and lipid degradation. This study experimentally investigates the impact of time and temperature on Nannochloropsis salina harvested from outdoor plate photobioreactors. The impact of three temperatures, 4°, 40° or 70°C, on biomass and lipid content (as fatty acid methyl esters of the harvested microalgae was evaluated over a 156 hour time period. Results show that for N. salina, time and temperature are key factors that negatively impact biomass and lipid yields. The temperature of 70°C resulted in the highest degradation with the overall biofuel potential reduced by 30% over 156 hours. Short time periods, 24 hours, and low temperatures are shown to have little effect on the harvested biomass.

  16. Maximum Plant Uptakes for Water, Nutrients, and Oxygen Are Not Always Met by Irrigation Rate and Distribution in Water-based Cultivation Systems.

    Science.gov (United States)

    Blok, Chris; Jackson, Brian E; Guo, Xianfeng; de Visser, Pieter H B; Marcelis, Leo F M

    2017-01-01

    cultivation in the DeepFlow negatively compared to substrate-based propagation. Water-based propagation resulted in frequent transient discolorations after transplanting in all cultivation systems, indicating a factor, other than irrigation supply of water, nutrients, and oxygen, influencing plant uptake. Plant uptake rates for water, nutrients, and oxygen are offered as a more fundamental way to compare and improve growing systems.

  17. Production of Microalgal Lipids as Biodiesel Feedstock with Fixation of CO2 by Chlorella vulgaris

    OpenAIRE

    Qiao Hu; Sen-Xiang Zhang; Zhong-Hua Yang; Hao Huang; Rong Zeng

    2014-01-01

    The global warming and shortage of energy are two critical problems for human social development. CO2 mitigation and replacing conventional diesel with biodiesel are effective routes to reduce these problems. Production of microalgal lipids as biodiesel feedstock by a freshwater microalga, Chlorella vulgaris, with the ability to fixate CO2 is studied in this work. The results show that nitrogen deficiency, CO2 volume fraction and photoperiod are the key factors responsible for the lipid accum...

  18. Spectroscopic analyses of chemical adaptation processes within microalgal biomass in response to changing environments

    Energy Technology Data Exchange (ETDEWEB)

    Vogt, Frank, E-mail: fvogt@utk.edu; White, Lauren

    2015-03-31

    Highlights: • Microalgae transform large quantities of inorganics into biomass. • Microalgae interact with their growing environment and adapt their chemical composition. • Sequestration capabilities are dependent on cells’ chemical environments. • We develop a chemometric hard-modeling to describe these chemical adaptation dynamics. • This methodology will enable studies of microalgal compound sequestration. - Abstract: Via photosynthesis, marine phytoplankton transforms large quantities of inorganic compounds into biomass. This has considerable environmental impacts as microalgae contribute for instance to counter-balancing anthropogenic releases of the greenhouse gas CO{sub 2}. On the other hand, high concentrations of nitrogen compounds in an ecosystem can lead to harmful algae blooms. In previous investigations it was found that the chemical composition of microalgal biomass is strongly dependent on the nutrient availability. Therefore, it is expected that algae’s sequestration capabilities and productivity are also determined by the cells’ chemical environments. For investigating this hypothesis, novel analytical methodologies are required which are capable of monitoring live cells exposed to chemically shifting environments followed by chemometric modeling of their chemical adaptation dynamics. FTIR-ATR experiments have been developed for acquiring spectroscopic time series of live Dunaliella parva cultures adapting to different nutrient situations. Comparing experimental data from acclimated cultures to those exposed to a chemically shifted nutrient situation reveals insights in which analyte groups participate in modifications of microalgal biomass and on what time scales. For a chemometric description of these processes, a data model has been deduced which explains the chemical adaptation dynamics explicitly rather than empirically. First results show that this approach is feasible and derives information about the chemical biomass

  19. Unexpected associated microalgal diversity in the lichen Ramalina farinacea is uncovered by pyrosequencing analyses.

    Directory of Open Access Journals (Sweden)

    Patricia Moya

    Full Text Available The current literature reveals that the intrathalline coexistence of multiple microalgal taxa in lichens is more common than previously thought, and additional complexity is supported by the coexistence of bacteria and basidiomycete yeasts in lichen thalli. This replaces the old paradigm that lichen symbiosis occurs between a fungus and a single photobiont. The lichen Ramalina farinacea has proven to be a suitable model to study the multiplicity of microalgae in lichen thalli due to the constant coexistence of Trebouxia sp. TR9 and T. jamesii in long-distance populations. To date, studies involving phycobiont diversity within entire thalli are based on Sanger sequencing, but this method seems to underestimate the diversity. Here, we aim to analyze both the microalgal diversity and its community structure in a single thallus of the lichen R. farinacea by applying a 454 pyrosequencing approach coupled with a careful ad hoc-performed protocol for lichen sample processing prior to DNA extraction. To ascertain the reliability of the pyrosequencing results and the applied bioinformatics pipeline results, the thalli were divided into three sections (apical, middle and basal zones, and a mock community sample was used. The developed methodology allowed 40448 filtered algal reads to be obtained from a single lichen thallus, which encompassed 31 OTUs representative of different microalgae genera. In addition to corroborating the coexistence of the two Trebouxia sp. TR9 and T. jamesii taxa in the same thallus, this study showed a much higher microalgal diversity associated with the lichen. Along the thallus ramifications, we also detected variations in phycobiont distribution that might correlate with different microenvironmental conditions. These results highlight R. farinacea as a suitable material for studying microalgal diversity and further strengthen the concept of lichens as multispecies microecosystems. Future analyses will be relevant to

  20. Spectroscopic analyses of chemical adaptation processes within microalgal biomass in response to changing environments

    International Nuclear Information System (INIS)

    Vogt, Frank; White, Lauren

    2015-01-01

    Highlights: • Microalgae transform large quantities of inorganics into biomass. • Microalgae interact with their growing environment and adapt their chemical composition. • Sequestration capabilities are dependent on cells’ chemical environments. • We develop a chemometric hard-modeling to describe these chemical adaptation dynamics. • This methodology will enable studies of microalgal compound sequestration. - Abstract: Via photosynthesis, marine phytoplankton transforms large quantities of inorganic compounds into biomass. This has considerable environmental impacts as microalgae contribute for instance to counter-balancing anthropogenic releases of the greenhouse gas CO 2 . On the other hand, high concentrations of nitrogen compounds in an ecosystem can lead to harmful algae blooms. In previous investigations it was found that the chemical composition of microalgal biomass is strongly dependent on the nutrient availability. Therefore, it is expected that algae’s sequestration capabilities and productivity are also determined by the cells’ chemical environments. For investigating this hypothesis, novel analytical methodologies are required which are capable of monitoring live cells exposed to chemically shifting environments followed by chemometric modeling of their chemical adaptation dynamics. FTIR-ATR experiments have been developed for acquiring spectroscopic time series of live Dunaliella parva cultures adapting to different nutrient situations. Comparing experimental data from acclimated cultures to those exposed to a chemically shifted nutrient situation reveals insights in which analyte groups participate in modifications of microalgal biomass and on what time scales. For a chemometric description of these processes, a data model has been deduced which explains the chemical adaptation dynamics explicitly rather than empirically. First results show that this approach is feasible and derives information about the chemical biomass adaptations

  1. Exploring the efficacy of wastewater-grown microalgal biomass as a biofertilizer for wheat.

    Science.gov (United States)

    Renuka, Nirmal; Prasanna, Radha; Sood, Anjuli; Ahluwalia, Amrik S; Bansal, Radhika; Babu, Santosh; Singh, Rajendra; Shivay, Yashbir S; Nain, Lata

    2016-04-01

    Microalgae possess the ability to grow and glean nutrients from wastewater; such wastewater-grown biomass can be used as a biofertilizer for crops. The present investigation was undertaken to evaluate two formulations (formulation with unicellular microalgae (MC1) and formulation with filamentous microalgae (MC2); T4 and T5, respectively), prepared using wastewater-grown microalgal biomass, as a biofertilizer (after mixing with vermiculite/compost as a carrier) in wheat crop (Triticum aestivum L. HD2967) under controlled conditions. The highest values of available nitrogen (N), phosphorus (P), and potassium (K) in soil and nitrogen-fixing potential were recorded in treatment T5 (75% N + full-dose PK + formulation with filamentous microalgae (MC2). Microbial biomass carbon was significantly enhanced by 31.8-67.0% in both the inoculated treatments over control (recommended dose of fertilizers), with highest values in T4 (75% N + full-dose PK + formulation with unicellular microalgae (MC1)). Both the microalgal formulations significantly increased the N, P, and K content of roots, shoots, and grains, and the highest total N content of 3.56% in grains was observed in treatment T5. At harvest stage, the treatments inoculated with microalgal formulations (T4 and T5) recorded a 7.4-33% increase in plant dry weight and up to 10% in spike weight. The values of 1000-grain weight showed an enhancement of 5.6-8.4%, compared with T1 (recommended doses of fertilizers). A positive correlation was observed between soil nutrient availability at mid crop stage and plant biometrical parameters at harvest stage. This study revealed the promise of such microalgal consortia as a biofertilizer for 25% N savings and improved yields of wheat crop.

  2. Growth and lipid accumulation characteristics of Scenedesmus obliquus in semi-continuous cultivation outdoors for biodiesel feedstock production.

    Science.gov (United States)

    Feng, Pingzhong; Yang, Kang; Xu, Zhongbin; Wang, Zhongming; Fan, Lu; Qin, Lei; Zhu, Shunni; Shang, Changhua; Chai, Peng; Yuan, Zhenhong; Hu, Lei

    2014-12-01

    In an effort to identify suitable microalgal species for biodiesel production, seven species were isolated from various habitats and their growth characteristics were compared. The results demonstrated that a green alga Scenedesmus obliquus could grow more rapidly and synthesize more lipids than other six microalgal strains. S. obliquus grew well both indoors and outdoors, and reached higher μmax indoors than that outdoors. However, the cells achieved higher dry weight (4.36 g L(-1)), lipid content (49.6%) and productivity (183 mg L(-1) day(-1)) outdoors than in indoor cultures. During the 61 days semi-continuous cultivation outdoors, high biomass productivities (450-550 mg L(-1) day(-1)) and μmax (1.05-1.44 day(-1)) were obtained. The cells could also achieve high lipid productivities (151-193 mg L(-1) day(-1)). These results indicated that S. obliquus was promising for lipids production in semi-continuous cultivation outdoors. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Microalgal drying and cell disruption--recent advances.

    Science.gov (United States)

    Show, Kuan-Yeow; Lee, Duu-Jong; Tay, Joo-Hwa; Lee, Tse-Min; Chang, Jo-Shu

    2015-05-01

    Production of intracellular metabolites or biofuels from algae involves various processing steps, and extensive work on laboratory- and pilot-scale algae cultivation, harvesting and processing has been reported. As algal drying and cell disruption are integral processes of the unit operations, this review examines recent advances in algal drying and disruption for nutrition or biofuel production. Challenges and prospects of the processing are also outlined. Engineering improvements in addressing the challenges of energy efficiency and cost-effective and rigorous techno-economic analyses for a clearer prospect comparison between different processing methods are highlighted. Holistic life cycle assessments need to be conducted in assessing the energy balance and the potential environmental impacts of algal processing. The review aims to provide useful information for future development of efficient and commercially viable algal food products and biofuels production. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Nile Red Staining for Oil Determination in Microalgal Cells: A New Insight through Statistical Modelling

    Directory of Open Access Journals (Sweden)

    Ronald Halim

    2015-01-01

    Full Text Available In the wake of global warming and rapid fossil fuel depletion, microalgae emerge as promising feedstocks for sustainable biofuel production. Nile red staining acts as a rapid diagnostic tool to measure the amount of biodiesel-convertible lipid that the cells accumulate. There is a need for the development of a more uniform staining procedure. In its first phase, this study examined the dependence of microalgal Nile red fluorescence (Tetraselmis suecica in terms of its most pertinent staining variables. A quadratic surface model that successfully described the Nile red fluorescence intensity as a composite function of its variables was generated (r2=0.86. Cell concentration was shown to have a significant effect on the fluorescence intensity. Up to a certain threshold, fluorescence intensity was shown to increase with Nile red dye concentration. In its second phase, the study reviewed findings from previous Nile red studies to elucidate some of the fundamental mechanism underlying the diffusion of Nile red dye molecules into the microalgal cells and their subsequent interaction with intracellular lipids. Through the review process, we were able to develop a simple framework that provided a set of guidelines for the standardization of the Nile red staining procedure across different microalgal species.

  5. Isolation and Cultivation of Anaerobes

    DEFF Research Database (Denmark)

    Aragao Börner, Rosa

    2016-01-01

    Anaerobic microorganisms play important roles in different biotechnological processes. Their complex metabolism and special cultivation requirements have led to less isolated representatives in comparison to their aerobic counterparts.In view of that, the isolation and cultivation of anaerobic...

  6. A Hydroponic Co-cultivation System for Simultaneous and Systematic Analysis of Plant/Microbe Molecular Interactions and Signaling.

    Science.gov (United States)

    Nathoo, Naeem; Bernards, Mark A; MacDonald, Jacqueline; Yuan, Ze-Chun

    2017-07-22

    An experimental design mimicking natural plant-microbe interactions is very important to delineate the complex plant-microbe signaling processes. Arabidopsis thaliana-Agrobacterium tumefaciens provides an excellent model system to study bacterial pathogenesis and plant interactions. Previous studies of plant-Agrobacterium interactions have largely relied on plant cell suspension cultures, the artificial wounding of plants, or the artificial induction of microbial virulence factors or plant defenses by synthetic chemicals. However, these methods are distinct from the natural signaling in planta, where plants and microbes recognize and respond in spatial and temporal manners. This work presents a hydroponic cocultivation system where intact plants are supported by metal mesh screens and cocultivated with Agrobacterium. In this cocultivation system, no synthetic phytohormone or chemical that induces microbial virulence or plant defense is supplemented. The hydroponic cocultivation system closely resembles natural plant-microbe interactions and signaling homeostasis in planta. Plant roots can be separated from the medium containing Agrobacterium, and the signaling and responses of both the plant hosts and the interacting microbes can be investigated simultaneously and systematically. At any given timepoint/interval, plant tissues or bacteria can be harvested separately for various "omics" analyses, demonstrating the power and efficacy of this system. The hydroponic cocultivation system can be easily adapted to study: 1) the reciprocal signaling of diverse plant-microbe systems, 2) signaling between a plant host and multiple microbial species (i.e. microbial consortia or microbiomes), 3) how nutrients and chemicals are implicated in plant-microbe signaling, and 4) how microbes interact with plant hosts and contribute to plant tolerance to biotic or abiotic stresses.

  7. Fully Automated On-Chip Imaging Flow Cytometry System with Disposable Contamination-Free Plastic Re-Cultivation Chip

    Directory of Open Access Journals (Sweden)

    Tomoyuki Kaneko

    2011-06-01

    Full Text Available We have developed a novel imaging cytometry system using a poly(methyl methacrylate (PMMA based microfluidic chip. The system was contamination-free, because sample suspensions contacted only with a flammable PMMA chip and no other component of the system. The transparency and low-fluorescence of PMMA was suitable for microscopic imaging of cells flowing through microchannels on the chip. Sample particles flowing through microchannels on the chip were discriminated by an image-recognition unit with a high-speed camera in real time at the rate of 200 event/s, e.g., microparticles 2.5 μm and 3.0 μm in diameter were differentiated with an error rate of less than 2%. Desired cells were separated automatically from other cells by electrophoretic or dielectrophoretic force one by one with a separation efficiency of 90%. Cells in suspension with fluorescent dye were separated using the same kind of microfluidic chip. Sample of 5 μL with 1 × 106 particle/mL was processed within 40 min. Separated cells could be cultured on the microfluidic chip without contamination. The whole operation of sample handling was automated using 3D micropipetting system. These results showed that the novel imaging flow cytometry system is practically applicable for biological research and clinical diagnostics.

  8. Analyzing a self-managed CHP system for greenhouse cultivation as a profitable way to reduce CO2-emissions

    International Nuclear Information System (INIS)

    Compernolle, Tine; Witters, Nele; Van Passel, Steven; Thewys, Theo

    2011-01-01

    To counter global warming, a transition to a low-carbon economy is needed. The greenhouse sector can contribute by installing Combined Heat and Power (CHP) systems, known for their excellent energy efficiency. Due to the recent European liberalization of the energy market, glass horticulturists have the opportunity to sell excess electricity to the market and by tailored policy and support measures, regional governments can fill the lack of technical and economic knowledge, causing initial resistance. This research investigates the economic and environmental opportunities using two detailed cases applying a self managed cogeneration system. The Net Present Value is calculated to investigate the economic feasibility. The Primary Energy Saving, the CO 2 Emission Reduction indicator and an Emission Balance are applied to quantify the environmental impact. The results demonstrate that a self-managed CHP system is economic viable and that CO 2 emissions are reduced.

  9. A Photobioreactor System for Precision Cultivation of Photoautotrophic Microorganisms and for High-Content Analysis of Suspension Dynamics

    Czech Academy of Sciences Publication Activity Database

    Nedbal, Ladislav; Trtílek, M.; Červený, Jan; Komárek, Ondřej; Pakrasi, Himadri B.

    2008-01-01

    Roč. 100, č. 5 (2008), s. 902-910 ISSN 0006-3592 R&D Projects: GA ČR GA206/05/0894 Institutional research plan: CEZ:AV0Z60870520 Keywords : algae * cyanobacteria * high-content monitoring * microbial growth * photosynthesis * systems biology Subject RIV: EI - Biotechnology ; Bionics Impact factor: 2.936, year: 2008

  10. [Dendrobium officinale stereoscopic cultivation method].

    Science.gov (United States)

    Si, Jin-Ping; Dong, Hong-Xiu; Liao, Xin-Yan; Zhu, Yu-Qiu; Li, Hui

    2014-12-01

    The study is aimed to make the most of available space of Dendrobium officinale cultivation facility, reveal the yield and functional components variation of stereoscopic cultivated D. officinale, and improve quality, yield and efficiency. The agronomic traits and yield variation of stereoscopic cultivated D. officinale were studied by operating field experiment. The content of polysaccharide and extractum were determined by using phenol-sulfuric acid method and 2010 edition of "Chinese Pharmacopoeia" Appendix X A. The results showed that the land utilization of stereoscopic cultivated D. officinale increased 2.74 times, the stems, leaves and their total fresh or dry weight in unit area of stereoscopic cultivated D. officinale were all heavier than those of the ground cultivated ones. There was no significant difference in polysaccharide content between stereoscopic cultivation and ground cultivation. But the extractum content and total content of polysaccharide and extractum were significantly higher than those of the ground cultivated ones. In additional, the polysaccharide content and total content of polysaccharide and extractum from the top two levels of stereoscopic culture matrix were significantly higher than that of the ones from the other levels and ground cultivation. Steroscopic cultivation can effectively improves the utilization of space and yield, while the total content of polysaccharides and extractum were significantly higher than that of the ground cultivated ones. The significant difference in Dendrobium polysaccharides among the plants from different height of stereo- scopic culture matrix may be associated with light factor.

  11. A modified closed flow through siphon system for the cultivation of marine or estuarine organisms under simulated conditions

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, K.K.C.; Gopalakrishnan, T.C.; Sankaranarayanan, V.N.; Desai, B.N.

    . Some of the principles used in the present modified design have come from the design of Nair et al., (1978) and Nair and Anger (1980) with lot of innovations to improve the working efficiency. The systems designed is protected under Government..., employing the same principles, in place of diarom/algal culture for water treatment, mangrove plants such as Rhizophora apiculata and Kandelia kandal were found very effective for removal of dissolved nutrients and other end products in the culture media...

  12. Vegetable Cultivation Hydroponics System In Community Economic Zone KEM Kanagarian Tikalak Subdistrict X Koto Singkarak Districts Solok

    OpenAIRE

    I Ketut Budaraga; Ramaiyulis; Ellyza nurdin

    2017-01-01

    Current conditions especially in urban agricultural land is getting narrower due to the rapid development. If left untreated it can lead to food security and environmental problems. One solution to allow the fulfillment of foodstuffs such as vegetables can be fulfilled for the people to exploit the potential of the narrow yard with continuous production of hydroponic systems. Interest dedication to the community to find ways to introduce a hydroponic vegetable crops that can supplement the fa...

  13. The use of nile tilapia ( Oreochromis niloticus) cultivation wastewater for the production of romaine lettuce ( Lactuca sativa L. var. longifolia) in water recirculation system

    Science.gov (United States)

    Effendi, Hefni; Wahyuningsih, Sri; Wardiatno, Yusli

    2017-10-01

    In the recirculation aquaponic system (RAS), fish farming waste was utilized as a nutrient for plant, minimizing the water need, reducing the waste disposal into the environment, and producing the fish and plant as well. The study aimed to examine the growth of romaine lettuce ( Lactuca sativa L. var. Longifolia) in aquaponic system without the addition of artificial nutrient. The nutrient relies solely on wastewater of nile tilapia ( Oreochromis niloticus) cultivation circulated continuously on the aquaponic system. The results showed that tilapia weight reached 48.49 ± 3.92 g of T3 (tilapia, romaine lettuce, and inoculated bacteria), followed by T2 (tilapia and romaine lettuce) and T1 (tilapia) of 47.80 ± 1.97 and 45.89 ± 1.10 g after 35 days of experiment. Tilapia best performance in terms of growth and production occurred at T3 of 3.96 ± 0.44 g/day, 12.10 ± 0.63 %/day, 96.11 ± 1.44 % and 1.60 ± 0.07 for GR, SGR, SR, and FCR, respectively. It is also indicated by better water quality characteristic in this treatment. Romaine lettuce harvests of T2 and T3 showed no significant difference, with the final weight of 61.87 ± 5.59 and 57.74 ± 4.35 g. Overall, the integration of tilapia fish farming and romaine lettuce is potentially a promising aquaponic system for sustainable fish and horticulture plant production.

  14. Cultivating an entrepreneurial mindset.

    Science.gov (United States)

    Matheson, Sandra A

    2013-01-01

    Now as never before, familiar challenges require bold, novel approaches. Registered dietitians will benefit by cultivating an entrepreneurial mindset that involves being comfortable with uncertainty, learning to take calculated risks, and daring to just try it. An entrepreneur is someone who takes risks to create something new, usually in business. But the entrepreneurial mindset is available to anyone prepared to rely only on their own abilities for their economic security and expect no opportunity without first creating value for others.

  15. Cultivating strategic thinking skills.

    Science.gov (United States)

    Shirey, Maria R

    2012-06-01

    This department highlights change management strategies that may be successful in strategically planning and executing organizational change initiatives. With the goal of presenting practical approaches helpful to nurse leaders advancing organizational change, content includes evidence-based projects, tools, and resources that mobilize and sustain organizational change initiatives. In this article, the author presents an overview of strategic leadership and offers approaches for cultivating strategic thinking skills.

  16. Transfer mechanisms in cultivated soils of waste radionuclides from electronuclear power plants in the system river--irrigated soil--underground water level

    Energy Technology Data Exchange (ETDEWEB)

    Saas, A; Grauby, A

    1974-12-31

    From symposinm on environmentl behavior of radionuclides released in the nuclear industry; Aix-en-Provence, France (14 May 1973). The location of nuclear power plants by rivers whose waters are used for irrigation and industrial and domestic consumption necessities a profound study of the river-irrigated soil- ground water system. Mechanisms of radionuclide transport in cultivated soil are considered under three principal aspects: the effect of the quality of the river water, of the irrigation channels, and of the ground water level on the mobility of the radionuclides in the soil; the influence of the type of soil (the four types of soils considered are acid brown soil, calcic brown soil, chalky brown soil, and chalky alluvial soil); and the distribution of radionuclides in the soil (hydrosoluble forms can contminate the ground water level and these are the forms in which they are taken up by plants. A study was made on the following nuclides: /sup 22/Na, /sup 137/Cs, /sup 85/Sr, /Sup 54/Mn, /Sup 59/Fe, /Sup 60/ Co, /sup 65/Zn, /sup 124/Sb, /sup 141 in the cultivated soils permit the evaluation of the risks of contmination of the food chain and of the underground water. This study also showed new perspectives of the behavior of radionuclides as a function of their contmination of the organo-mineral wastes of industrial and domestic origin. This pollution interfers largely with the formation of stble complexes carried by the river to irrigated soils. The quality of the water determines the distribution of the radionuclides in the profile. The hydrosoluble complex persists in the soil and migrates toward the underground water level if they are not biodegradable. The stability of these forms as a function of the soil pH and of its physicochemical characteristics, as well as that of the radionuclides considered, permit the formulation of a new balance of the radionuclides in soils. The formulation of new proposals for the contml of nuclear sites is discussed. (tr-auth)

  17. Microbe observation and cultivation array (MOCA) for cultivating and analyzing environmental microbiota.

    Science.gov (United States)

    Gao, Weimin; Navarroli, Dena; Naimark, Jared; Zhang, Weiwen; Chao, Shih-Hui; Meldrum, Deirdre R

    2013-01-09

    The use of culture-independent nucleic acid techniques, such as ribosomal RNA gene cloning library analysis, has unveiled the tremendous microbial diversity that exists in natural environments. In sharp contrast to this great achievement is the current difficulty in cultivating the majority of bacterial species or phylotypes revealed by molecular approaches. Although recent new technologies such as metagenomics and metatranscriptomics can provide more functionality information about the microbial communities, it is still important to develop the capacity to isolate and cultivate individual microbial species or strains in order to gain a better understanding of microbial physiology and to apply isolates for various biotechnological applications. We have developed a new system to cultivate bacteria in an array of droplets. The key component of the system is the microbe observation and cultivation array (MOCA), which consists of a Petri dish that contains an array of droplets as cultivation chambers. MOCA exploits the dominance of surface tension in small amounts of liquid to spontaneously trap cells in well-defined droplets on hydrophilic patterns. During cultivation, the growth of the bacterial cells across the droplet array can be monitored using an automated microscope, which can produce a real-time record of the growth. When bacterial cells grow to a visible microcolony level in the system, they can be transferred using a micropipette for further cultivation or analysis. MOCA is a flexible system that is easy to set up, and provides the sensitivity to monitor growth of single bacterial cells. It is a cost-efficient technical platform for bioassay screening and for cultivation and isolation of bacteria from natural environments.

  18. Quantitative measurement of damage caused by 1064-nm wavelength optical trapping of Escherichia coli cells using on-chip single cell cultivation system

    International Nuclear Information System (INIS)

    Ayano, Satoru; Wakamoto, Yuichi; Yamashita, Shinobu; Yasuda, Kenji

    2006-01-01

    We quantitatively examined the possible damage to the growth and cell division ability of Escherichia coli caused by 1064-nm optical trapping. Using the synchronous behavior of two sister E. coli cells, the growth and interdivision times between those two cells, one of which was trapped by optical tweezers, the other was not irradiated, were compared using an on-chip single cell cultivation system. Cell growth stopped during the optical trapping period, even with the smallest irradiated power on the trapped cells. Moreover, the damage to the cell's growth and interdivision period was proportional to the total irradiated energy (work) on the cell, i.e., irradiation time multiplied by irradiation power. The division ability was more easily affected by a smaller energy, 0.36 J, which was 30% smaller than the energy that adversely affected growth, 0.54 J. The results indicate that the damage caused by optical trapping can be estimated from the total energy applied to cells, and furthermore, that the use of optical trapping for manipulating cells might cause damage to cell division and growth mechanisms, even at wavelengths under 1064 nm, if the total irradiation energy is excessive

  19. Process Integration for the Disruption of Candida guilliermondii Cultivated in Rice Straw Hydrolysate and Recovery of Glucose-6-Phosphate Dehydrogenase by Aqueous Two-Phase Systems.

    Science.gov (United States)

    Gurpilhares, Daniela B; Pessoa, Adalberto; Roberto, Inês C

    2015-07-01

    Remaining cells of Candida guilliermondii cultivated in hemicellulose-based fermentation medium were used as intracellular protein source. Recovery of glucose-6-phosphate dehydrogenase (G6PD) was attained in conventional aqueous two-phase systems (ATPS) was compared with integrated process involving mechanical disruption of cells followed by ATPS. Influences of polyethylene glycol molar mass (M PEG) and tie line lengths (TLL) on purification factor (PF), yields in top (Y T ) and bottom (Y B ) phases and partition coefficient (K) were evaluated. First scheme resulted in 65.9 % enzyme yield and PF of 2.16 in salt-enriched phase with clarified homogenate (M PEG 1500 g mol(-1), TLL 40 %); Y B of 75.2 % and PF B of 2.9 with unclarified homogenate (M PEG 1000 g mol(-1), TLL 35 %). The highest PF value of integrated process was 2.26 in bottom phase (M PEG 1500 g mol(-1), TLL 40 %). In order to optimize this response, a quadratic model was predicted for the response PFB for process integration. Maximum response achieved was PFB = 3.3 (M PEG 1500 g mol(-1), TLL 40 %). Enzyme characterization showed G6P Michaelis-Menten constant (K M ) equal 0.07-0.05, NADP(+) K M 0.02-1.98 and optimum temperature 70 °C, before and after recovery. Overall, our data confirmed feasibility of disruption/extraction integration for single-step purification of intracellular proteins from remaining yeast cells.

  20. Whole genome sequence analysis of Geitlerinema sp. FC II unveils competitive edge of the strain in marine cultivation system for biofuel production.

    Science.gov (United States)

    Batchu, Navish Kumar; Khater, Shradha; Patil, Sonal; Nagle, Vinod; Das, Gautam; Bhadra, Bhaskar; Sapre, Ajit; Dasgupta, Santanu

    2018-03-05

    A filamentous cyanobacteria, Geitlerinema sp. FC II, was isolated from marine algae culture pond at Reliance Industries Limited (RIL), India. The 6.7 Mb draft genome of FC II encodes for 6697 protein coding genes. Analysis of the whole genome sequence revealed presence of nif gene cluster, supporting its capability to fix atmospheric nitrogen. FC II genome contains two variants of sulfide:quinone oxidoreductases (SQR), which is a crucial elector donor in cyanobacterial metabolic processes. FC II is characterized by the presence of multiple CRISPR- Cas (Clustered Regularly Interspaced Short Palindrome Repeats - CRISPR associated proteins) clusters, multiple variants of genes encoding photosystem reaction centres, biosynthetic gene clusters of alkane, polyketides and non-ribosomal peptides. Presence of these pathways will help FC II in gaining an ecological advantage over other strains for biomass production in large scale cultivation system. Hence, FC II may be used for production of biofuel and other industrially important metabolites. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. Novel schemes for production of biodiesel and value-added co-products from microalgal oil using heterogeneous catalysts

    Science.gov (United States)

    Dong, Tao

    Microalgae are promising sources of biofuels primarily because of their higher potential productivity compared to terrestrial biofuel crops. However, the production of liquid fuels from microalgae suffers from a lack of viable methods of extraction, conversion and fractionation of various components of the algal biomass. In this dissertation study, a rapid method was developed to accurately evaluate the biodiesel potential of microalgae biomass. The major advantage of this method is in situ fatty acid methyl ester (FAME) preparation directly from wet fresh microalgal and yeast biomass, without prior solvent extraction or dehydration. FAMEs were prepared by a sequential alkaline hydrolysis and acidic esterification process. This method can be used even with high amount of water in the biomass and is applicable to a vast range of microalgae and yeast species. A two-step in situ process was also investigated in this study to obtain a high FAME yield from microalgae biomass that had high free fatty acids (FFA) content. This process has the potential to reduce the production cost of microalgae-derived FAME and be more environmental compatible due to the higher FAME yield with reduced catalyst consumption. A cost-effective bio-char based catalyst was tested for the two-step biodiesel production. The results indicated that the bio-char catalyst was superior to commercial Amberly-15. A scalable chlorophyll remove process was also developed as a part of the system. The research resulted in a practical and cost-effective approach for producing biodiesel from crude microalgal oil. An integrated approach was explored in the fourth part of the study to produce biodiesel and fractionate high-value polyunsaturated fatty acid (PUFA). Zeolites were employed as the catalyst for selective esterification of fatty acids according to their chain length and degree of saturation. Low-value short chain FFA could be largely converted into FAME, while PUFA would remain unreacted due to

  2. Coupling auto trophic in vitro plant cultivation system to scanning electron microscope to study plant-fungal interactions

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, N. de; Decock, C.; Declereck, S.; Providencia, I. E. de la

    2010-07-01

    The interactions of plants with pathogens and beneficial micro-organisms have been seldom compared on the same host and under strict controlled auto trophic in vitro culture conditions. Here, the life cycle of two plant beneficial (Glomus sp. MUCL 41833 and Trichoderma harzianum) and one plant pathogen (Rhizoctonia solani) fungi were described on potato (Solanum tuberosum) plantlets under auto trophic in vitro culture conditions using video camera imaging and the scanning electron microscope (SEM). (i) The colony developmental pattern of the extraradical mycelium within the substrate, (ii) the reproduction structures and (iii) the three-dimensional spatial arrangements of the fungal hyphae within the potato root cells were successfully visualized, monitored and described. The combination of the autotrophic in vitro culture system and SEM represent a powerful tool for improving our knowledge on the dynamics of plant-fungal interactions. (Author) 41 refs.

  3. Harvesting Environmental Microalgal Blooms for Remediation and Resource Recovery: A Laboratory Scale Investigation with Economic and Microbial Community Impact Assessment

    Directory of Open Access Journals (Sweden)

    Jagroop Pandhal

    2017-12-01

    Full Text Available A laboratory based microflotation rig termed efficient FLOtation of Algae Technology (eFLOAT was used to optimise parameters for harvesting microalgal biomass from eutrophic water systems. This was performed for the dual objectives of remediation (nutrient removal and resource recovery. Preliminary experiments demonstrated that chitosan was more efficient than alum for flocculation of biomass and the presence of bacteria could play a positive role and reduce flocculant application rates under the natural conditions tested. Maximum biomass removal from a hyper-eutrophic water retention pond sample was achieved with 5 mg·L−1 chitosan (90% Chlorophyll a removal. Harvesting at maximum rates showed that after 10 days, the bacterial diversity is significantly increased with reduced cyanobacteria, indicating improved ecosystem functioning. The resource potential within the biomass was characterized by 9.02 μg phosphate, 0.36 mg protein, and 103.7 μg lipid per mg of biomass. Fatty acid methyl ester composition was comparable to pure cultures of microalgae, dominated by C16 and C18 chain lengths with saturated, monounsaturated, and polyunsaturated fatty acids. Finally, the laboratory data was translated into a full-size and modular eFLOAT system, with estimated costs as a novel eco-technology for efficient algal bloom harvesting.

  4. Comparative Effects of Biomass Pre-Treatments for Direct and Indirect Transesterification to Enhance Microalgal Lipid Recovery

    International Nuclear Information System (INIS)

    Ghasemi Naghdi, Forough; Thomas-Hall, Skye R.; Durairatnam, Reuben; Pratt, Steven; Schenk, Peer M.

    2014-01-01

    Microalgal lipid recovery for biodiesel production is currently considered suboptimal, but pre-treatment of algal biomass, the use of solvent mixtures and the positioning of transesterification can lead to increased yields. Here, the effect of various reportedly successful pre-treatments and solvent mixtures were directly compared to each other and combined with direct and indirect transesterification methods using the oleaginous microalga Tetraselmis sp. M8. Microwave and thermal pre-treatments were applied and the total lipid and fatty acid methyl ester (FAME) recoveries were investigated. The application of pre-treatments increased FAME recovery through indirect transesterification when a Soxhlet system was used but they had no significant effect for direct transesterification. Gravimetric analyses of total lipids revealed that lipid recovery was highest when utilizing the chloroform-based Bligh and Dyer extraction method; however, FAME yield was the highest when applying a Soxhlet system utilizing a solvent mixture of hexane–ethanol (3:1). Total lipid recovery did not necessarily correlate with the recovery of FAMEs. The highest FAME recovery was achieved from thermal or microwave pre-treated biomass followed by indirect transesterification through Soxhlet extraction. FAME recovery could be more than doubled (increase of up to 171%) under these conditions. We conclude that a simple thermal pre-treatment (80°C for 10 min) in combination with solvent mixture extraction through indirect transesterification may present a cost-effective and scalable option for large-scale lipid extraction from microalgae.

  5. Comparative effects of biomass pre-treatments for direct and indirect transesterification to enhance microalgal lipid recovery

    Directory of Open Access Journals (Sweden)

    Forough eGhasemi Naghdi

    2014-12-01

    Full Text Available Microalgal lipid recovery for biodiesel production is currently considered suboptimal, but pre-treatment of algal biomass, the use of solvent mixtures and the positioning of transesterification can lead to increased yields. Here, the effect of various reportedly successful pre-treatments and solvent mixtures were directly compared to each other and combined with direct and indirect transesterification methods using the oleaginous microalga Tetraselmis sp. M8. Microwave and thermal pre-treatments were applied and the total lipid and fatty acid methyl ester (FAME recoveries were investigated. The application of pre-treatments increased FAME recovery through indirect transesterification when a Soxhlet system was used but they had no significant effect for direct transesterification. Gravimetric analyses of total lipids revealed that lipid recovery was highest when utilizing the chloroform-based Bligh and Dyer extraction method; however FAME yield was the highest when applying a Soxhlet system utilizing a solvent mixture of hexane-ethanol (3:1. Total lipid recovery did not necessarily correlate with the recovery of FAMEs. The highest FAME recovery was achieved from thermal or microwave pre-treated biomass followed by indirect transesterification through Soxhlet extraction. FAME recovery could be more than doubled (increase of up to 171% under these conditions. We conclude that a simple thermal pre-treatment (80°C for 10 min in combination with solvent mixture extraction through indirect transesterification may present a cost-effective and scalable option for large-scale lipid extraction from microalgae.

  6. Comparative Effects of Biomass Pre-Treatments for Direct and Indirect Transesterification to Enhance Microalgal Lipid Recovery

    Energy Technology Data Exchange (ETDEWEB)

    Ghasemi Naghdi, Forough; Thomas-Hall, Skye R.; Durairatnam, Reuben [Algae Biotechnology Laboratory, School of Agriculture and Food Sciences, The University of Queensland, Brisbane, QLD (Australia); Pratt, Steven [School of Chemical Engineering, The University of Queensland, Brisbane, QLD (Australia); Schenk, Peer M., E-mail: p.schenk@uq.edu.au [Algae Biotechnology Laboratory, School of Agriculture and Food Sciences, The University of Queensland, Brisbane, QLD (Australia)

    2014-12-04

    Microalgal lipid recovery for biodiesel production is currently considered suboptimal, but pre-treatment of algal biomass, the use of solvent mixtures and the positioning of transesterification can lead to increased yields. Here, the effect of various reportedly successful pre-treatments and solvent mixtures were directly compared to each other and combined with direct and indirect transesterification methods using the oleaginous microalga Tetraselmis sp. M8. Microwave and thermal pre-treatments were applied and the total lipid and fatty acid methyl ester (FAME) recoveries were investigated. The application of pre-treatments increased FAME recovery through indirect transesterification when a Soxhlet system was used but they had no significant effect for direct transesterification. Gravimetric analyses of total lipids revealed that lipid recovery was highest when utilizing the chloroform-based Bligh and Dyer extraction method; however, FAME yield was the highest when applying a Soxhlet system utilizing a solvent mixture of hexane–ethanol (3:1). Total lipid recovery did not necessarily correlate with the recovery of FAMEs. The highest FAME recovery was achieved from thermal or microwave pre-treated biomass followed by indirect transesterification through Soxhlet extraction. FAME recovery could be more than doubled (increase of up to 171%) under these conditions. We conclude that a simple thermal pre-treatment (80°C for 10 min) in combination with solvent mixture extraction through indirect transesterification may present a cost-effective and scalable option for large-scale lipid extraction from microalgae.

  7. Evaluation of the integrated hydrothermal carbonization-algal cultivation process for enhanced nitrogen utilization in Arthrospira platensis production.

    Science.gov (United States)

    Yao, Changhong; Wu, Peichun; Pan, Yanfei; Lu, Hongbin; Chi, Lei; Meng, Yingying; Cao, Xupeng; Xue, Song; Yang, Xiaoyi

    2016-09-01

    Sustainable microalgal cultivation at commercial scale requires nitrogen recycling. This study applied hydrothermal carbonization to recover N of hot-water extracted Arthrospira platensis biomass residue into aqueous phase (AP) under different operation conditions and evaluated the N utilization, biomass yield and quality of A. platensis cultures using AP as the sole N source. With the increase of temperature at 190-210°C or reaction time of 2-3h, the N recovery rate decreased under nitrogen-repletion (+N) cultivation, while contrarily increased under nitrogen-limitation (-N) cultivation. Under +N biomass accumulation in the cultures with AP under 190°C was enhanced by 41-67% compared with that in NaNO3, and the highest protein content of 51.5%DW achieved under 200°C-2h was also 22% higher. Carbohydrate content of 71.4%DW under -N cultivation achieved under 210°C-3h was 14% higher than that in NaNO3. HTC-algal cultivation strategy under -N mode could save 60% of conventional N. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. In Vitro Model for Hepatotoxicity Studies Based on Primary Human Hepatocyte Cultivation in a Perfused 3D Bioreactor System.

    Science.gov (United States)

    Knöspel, Fanny; Jacobs, Frank; Freyer, Nora; Damm, Georg; De Bondt, An; van den Wyngaert, Ilse; Snoeys, Jan; Monshouwer, Mario; Richter, Marco; Strahl, Nadja; Seehofer, Daniel; Zeilinger, Katrin

    2016-04-16

    Accurate prediction of the potential hepatotoxic nature of new pharmaceuticals remains highly challenging. Therefore, novel in vitro models with improved external validity are needed to investigate hepatic metabolism and timely identify any toxicity of drugs in humans. In this study, we examined the effects of diclofenac, as a model substance with a known risk of hepatotoxicity in vivo, in a dynamic multi-compartment bioreactor using primary human liver cells. Biotransformation pathways of the drug and possible effects on metabolic activities, morphology and cell transcriptome were evaluated. Formation rates of diclofenac metabolites were relatively stable over the application period of seven days in bioreactors exposed to 300 µM diclofenac (300 µM bioreactors (300 µM BR)), while in bioreactors exposed to 1000 µM diclofenac (1000 µM BR) metabolite concentrations declined drastically. The biochemical data showed a significant decrease in lactate production and for the higher dose a significant increase in ammonia secretion, indicating a dose-dependent effect of diclofenac application. The microarray analyses performed revealed a stable hepatic phenotype of the cells over time and the observed transcriptional changes were in line with functional readouts of the system. In conclusion, the data highlight the suitability of the bioreactor technology for studying the hepatotoxicity of drugs in vitro.

  9. In Vitro Model for Hepatotoxicity Studies Based on Primary Human Hepatocyte Cultivation in a Perfused 3D Bioreactor System

    Directory of Open Access Journals (Sweden)

    Fanny Knöspel

    2016-04-01

    Full Text Available Accurate prediction of the potential hepatotoxic nature of new pharmaceuticals remains highly challenging. Therefore, novel in vitro models with improved external validity are needed to investigate hepatic metabolism and timely identify any toxicity of drugs in humans. In this study, we examined the effects of diclofenac, as a model substance with a known risk of hepatotoxicity in vivo, in a dynamic multi-compartment bioreactor using primary human liver cells. Biotransformation pathways of the drug and possible effects on metabolic activities, morphology and cell transcriptome were evaluated. Formation rates of diclofenac metabolites were relatively stable over the application period of seven days in bioreactors exposed to 300 µM diclofenac (300 µM bioreactors (300 µM BR, while in bioreactors exposed to 1000 µM diclofenac (1000 µM BR metabolite concentrations declined drastically. The biochemical data showed a significant decrease in lactate production and for the higher dose a significant increase in ammonia secretion, indicating a dose-dependent effect of diclofenac application. The microarray analyses performed revealed a stable hepatic phenotype of the cells over time and the observed transcriptional changes were in line with functional readouts of the system. In conclusion, the data highlight the suitability of the bioreactor technology for studying the hepatotoxicity of drugs in vitro.

  10. Effects of pH control and concentration on microbial oil production from Chlorella vulgaris cultivated in the effluent of a low-cost organic waste fermentation system producing volatile fatty acids.

    Science.gov (United States)

    Cho, Hyun Uk; Kim, Young Mo; Choi, Yun-Nam; Xu, Xu; Shin, Dong Yun; Park, Jong Moon

    2015-05-01

    The objective of this study was to investigate the feasibility of applying volatile fatty acids (VFAs) produced from low-cost organic waste to the major carbon sources of microalgae cultivation for highly efficient biofuel production. An integrated process that consists of a sewage sludge fermentation system producing VFAs (SSFV) and mixotrophic cultivation of Chlorella vulgaris (C. vulgaris) was operated to produce microbial lipids economically. The effluents from the SSFV diluted to different concentrations at the level of 100%, 50%, and 15% were prepared for the C. vulgaris cultivation and the highest biomass productivity (433±11.9 mg/L/d) was achieved in the 100% culture controlling pH at 7.0. The harvested biomass included lipid contents ranging from 12.87% to 20.01% under the three different effluent concentrations with and without pH control. The composition of fatty acids from C. vulgaris grown on the effluents from the SSFV complied with the requirements of high-quality biodiesel. These results demonstrated that VFAs produced from the SSFV are favorable carbon sources for cultivating C. vulgaris. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Transition in nori cultivation

    DEFF Research Database (Denmark)

    Delaney, Alyne

    2011-01-01

    . Technological change has had a profound impact on both the manner of nori production as well as the household division of labor and work and gender roles. Women play a key role in nori production today. With better understanding of such outward manifestations of culture and society we can bring the human...... of social and environmental sustainability, we must understand both society and cultural institutions. With this in mind, this article focuses on the division of labor among cultivators, particularly along gender lines and the impacts, on a cultural level, of technological change on nori production...

  12. Microgravity cultivation of cells and tissues

    Science.gov (United States)

    Freed, L. E.; Pellis, N.; Searby, N.; de Luis, J.; Preda, C.; Bordonaro, J.; Vunjak-Novakovic, G.

    1999-01-01

    In vitro studies of cells and tissues in microgravity, either simulated by cultivation conditions on earth or actual, during spaceflight, are expected to help identify mechanisms underlying gravity sensing and transduction in biological organisms. In this paper, we review rotating bioreactor studies of engineered skeletal and cardiovascular tissues carried out in unit gravity, a four month long cartilage tissue engineering study carried out aboard the Mir Space Station, and the ongoing laboratory development and testing of a system for cell and tissue cultivation aboard the International Space Station.

  13. Microalgae Cultivation on Anaerobic Digestate of Municipal Wastewater, Sewage Sludge and Agro-Waste

    Directory of Open Access Journals (Sweden)

    Luca Zuliani

    2016-10-01

    Full Text Available Microalgae are fast-growing photosynthetic organisms which have the potential to be exploited as an alternative source of liquid fuels to meet growing global energy demand. The cultivation of microalgae, however, still needs to be improved in order to reduce the cost of the biomass produced. Among the major costs encountered for algal cultivation are the costs for nutrients such as CO2, nitrogen and phosphorous. In this work, therefore, different microalgal strains were cultivated using as nutrient sources three different anaerobic digestates deriving from municipal wastewater, sewage sludge or agro-waste treatment plants. In particular, anaerobic digestates deriving from agro-waste or sewage sludge treatment induced a more than 300% increase in lipid production per volume in Chlorella vulgaris cultures grown in a closed photobioreactor, and a strong increase in carotenoid accumulation in different microalgae species. Conversely, a digestate originating from a pilot scale anaerobic upflow sludge blanket (UASB was used to increase biomass production when added to an artificial nutrient-supplemented medium. The results herein demonstrate the possibility of improving biomass accumulation or lipid production using different anaerobic digestates.

  14. Radiological aspects of choice of a system of cultivation of sod-podzolic sandy loam soils with different degree of humidity on lands of Mogilev region contaminated with 137Cs

    International Nuclear Information System (INIS)

    Lazarevich, S.S.; Ermolenko, A.V.; Shapsheeva, T.P.

    2010-01-01

    In the conditions of the Republic of Belarus there were presented data about the influence of technological factors on entry of 137Cs into plant products (grain and green mass). In course of the study there were analyzed the following variants of soil cultivation: moldboard plowing; subsurface chisel soil tillage; subsurface surface soil tillage; minimal tillage. There were presented data on specific activity of 137Cs in plant product samples of oat (Avena sativa) grain; field pea (Pisum arvense L.) and oat mixture grain and green mass; wheat (Triticum aestivum) grain. There were determined the main principles of influence of cultivation systems of sod-podzolic sandy loam soil with different degree of humidity on transition of 137Cs into plants depending on the degree of soil and crop humidity. On the automorphic soil there was revealed a tendency of increased transition of 137Cs into grain and green mass after application of subsurface surface soil tillage system

  15. Effects of co-products on the life-cycle impacts of microalgal biodiesel.

    Science.gov (United States)

    Soratana, Kullapa; Barr, William J; Landis, Amy E

    2014-05-01

    Microalgal biodiesel production has been investigated for decades, yet it is not commercially available. Part of the problem is that the production process is energy and chemical intensive due, in part, to the high portion of microalgal biomass left as residues. This study investigated cradle-to-gate life-cycle environmental impacts from six different scenarios of microalgal biodiesel and its co-products. Ozone depletion, global warming, photochemical smog formation, acidification and eutrophication potentials were assessed using the Tool for the Reduction and Assessment of Chemical and other environmental Impacts (TRACI). Monte Carlo Analysis was conducted to investigate the processes with major contribution in each impact category. The market opportunity for each co-product was examined based on supply, demand and prices of the products that could potentially be substituted by the co-products. The results indicated that the scenario with the least life-cycle environmental impacts in all the five impact categories with the highest net energy ratio was the scenario utilizing a multitude of co-products including bioethanol from lipid-extracted microalgae (LEA), biomethane (to produce electricity and heat) from simultaneous saccharification-fermentation (SSF) residues, land-applied material from SSF residue anaerobic digestion (AD) solid digestate, recycling nutrients from SSF residue AD liquid digestate and CO2 recovered from SSF process contributed. Decreasing the energy consumption of the centrifuge in the land-applied material production process and increasing the lipid content of microalgae can reduce environmental footprints of the co-products. The same scenario also had the highest total income indicating their potential as co-products in the market. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Inhibitory activities of microalgal extracts against Epstein-Barr Virus (EBV antigen expression in lymphoblastoid cells

    Directory of Open Access Journals (Sweden)

    Koh Yih Yih

    2014-01-01

    Full Text Available The inhibitory activities of microalgal extracts against the expression of three EBV antigens, latent membrane protein (LMP1, Epstein-Barr nuclear antigen (EBNA1 and Z Epstein-Barr reactivation activator (ZEBRA were assessed by immunocytochemistry. The observation that the methanol extracts and their fractions from Ankistrodesmus convolutus, Synechococcus elongatus and Spirulina platensis exhibited inhibitory activity against EBV proteins in three Burkitt’s lymphoma cell lines at concentrations as low as 20 μg/ml suggests that microalgae could be a potential source of antiviral compounds against EBV.

  17. Microalgal process-monitoring based on high-selectivity spectroscopy tools: status and future perspectives

    DEFF Research Database (Denmark)

    Podevin, Michael Paul Ambrose; Fotidis, Ioannis; Angelidaki, Irini

    2018-01-01

    microalgae production towards process automation through multivariate process control (MVPC) and software sensors trained on “big data”. The paper will also include a comprehensive overview of off-line implementations of vibrational spectroscopy in microalgal research as it pertains to spectral...... contribution of this review is to present current and prospective advances of on-line and in-line process analytical technology (PAT), with high-selectivity – the capability of monitoring several analytes simultaneously – in the interest of improving product quality, productivity, and process automation...... interpretation and process automation to aid and motivate development....

  18. Fruit sphere microenvironments and berry phenolic content of Cabernet Sauvignon (Vitis vinifera L. cultivated under rain-shelter systems with coloured plastic film

    Directory of Open Access Journals (Sweden)

    Jiang-Fei MENG

    Full Text Available Abstract Rain-shelter cultivation has been proven an important cultivation method for grape-plantings in continental monsoon climate zones, of which white plastic films are the most common shelter material. However, while this method and material reduces the occurrence of the disease, it can also decrease the grape berry quality. Five colours (including red, yellow, blue, purple, and white of plastic films were covered above Cabernet Sauvignon (Vitis vinifera L. grapevine rows before veraison. Rain-shelter cultivation reduced air temperature, wind speed, and total solar radiation and enhanced relative humidity in the fruit sphere of grapevines. For each particular colour plastic film, the irradiance of its corresponding spectrum band in the canopy of vines was higher than with other colour plastic films. Meanwhile, the blue plastic film treatment significantly promoted the accumulation of total phenolics, anthocyanins, flavonoids, tannins, and phenolic acids more than the other colours of plastic films. Blue plastic films are more beneficial for berry quality promotion of wine grapes, especially Cabernet Sauvignon, under rain-shelter cultivation in continental monsoon climate zones.

  19. Glass bead cultivation of fungi

    DEFF Research Database (Denmark)

    Droce, Aida; Sørensen, Jens Laurids; Giese, H.

    2013-01-01

    Production of bioactive compounds and enzymes from filamentous fungi is highly dependent on cultivation conditions. Here we present an easy way to cultivate filamentous fungi on glass beads that allow complete control of nutrient supply. Secondary metabolite production in Fusarium graminearum...... and Fusarium solani cultivated on agar plates, in shaking liquid culture or on glass beads was compared. Agar plate culture and glass bead cultivation yielded comparable results while liquid culture had lower production of secondary metabolites. RNA extraction from glass beads and liquid cultures was easier...... to specific nutrient factors. •Fungal growth on glass beads eases and improves fungal RNA extraction....

  20. ADAPTIVE ENERGY-SAVING CULTIVATOR FOR STONY SOILS CULTIVATING

    Directory of Open Access Journals (Sweden)

    A. B. Kudzaev

    2015-01-01

    Full Text Available Practice of cultivators operation on stony soils in RNO-Alania with high hardness and humidity indicates that traction resistance during the work varies widely, with deviation from the mean value by more than 2 times. Optimally adjust the machine to the soil background when using most modern mechanisms of regulation is not always possible. Customizing the data machine boils down to the choice of priority between the vibration of the working bodies in the soil, the maintenance of the given depth and power reserve stands required to crawl the working body of the big stones. It is very difficult to get in practice the best combination of these three factors, especially on stony soils. Therefore, the machine must be designed with the ability to quickly adjust to changing operating conditions and modes to ensure energy-saving effects and not violations of the specified soil depth of various hardness with the possibility of equipping the machine racks with different working bodies. The interrow cultivator with the possibility of the quick adjustment (including automated to varying conditions was developed. In the process of studied basic parameters of elastic composite racks and parameters of pneumatic mechanism drive to adjust the proposed section of the machine were established. The system hardiness in layouts by elastic bars with air pressure up to 0.6 MPa varies from 17.7 to 45.3 N/mm. It was received effective values of pressures 0.4-0.5 MPa in the pneumatic drive partitions of the machine when operating with universal blade and ridger body OK-3 on stony soil. As a result, traction resistance decreases by 30-35 percent.

  1. The evaluation of the growth and nutrition conditions of the garden nursery material Prunus and Thuja according to the use of various cultivating substrates and systems of fertilization

    Directory of Open Access Journals (Sweden)

    Tomáš Meisl

    2006-01-01

    Full Text Available The influence of different peat-based cultivating substrates and the system of fertilization on the nutrition conditions and growth characteristics of garden nursery material Prunus kurilensis ‘Brillant’ and Thuja occidentalis ‘Smaragd’ were observed during a three-year experiment. Three kinds of substrates were tested: peat + pumice (pemza proportioned 8:2, fermented bark + peat + clay proportioned 4:4:2, fermented bark + peat + clay proportioned 4:4:2. Two fertilizers were used: granular controlled-release fertilizer – Osmocote, and watersoluble with irrigation – Kristalon.A higher content of macroelements was observed in the leaves of Prunus. The only exception was potassium, the quantity of which was demonstrably higher in the assimilative organs of Thuja. On the contrary, Thuja had a higher content of trace elements except for copper and iron. The highest contents of nitrogen, potassium, and iron were statistically proved in leaves of woods grown in the substrate of peat and pumice due to its higher sorption capability. A better nutrition conditions in almost all nutrients were observed at plants where the gradually effective Osmocote was applied. The exceptions were calcium, molybdenum and iron, the content of which was, on the contrary, higher where Kristalon with irrigation were used. Physical characteristics of the growing substrates that contained bark were significantly worse at the end of the experiment. This was even intensified by clay. The substrate containing peat and pumice were less stable. The best growth was observed in woods grown in the substrate of peat and pumice, ie where peat was not substituted by bark, and, at the same time, expanded clay was used instead of classic clay. Higher values of growth characteristics were demonstratively observed after the Osmocote fertilizer was applied.The results of the experiment reveal that pumice should be recommended, pemza with a high sorption capability and the

  2. Starting from grape cultivation.

    Science.gov (United States)

    Yoshida, A

    1992-06-01

    Rapid population growth can only be stopped by lowering the fertility rate. The UNFPA recommends improving the employment opportunities for women as the single best way of achieving this reduction. An example of this phenomenon is the grape cultivation in the Nordeste (Northeastern) region of Brazil. This area is the poorest part of Brazil and has the highest proportion of indigent people. These people have been deforesting the Amazon in search of a better life. What they have done is sterilize the land and turned a tropical rain forest into a desert. In an effort to reverse this trend, grape cultivation has been introduced in an area called Petrolina. The area is very dry with less than 500 mm of precipitation annually. They do have access to a 5000 square kilometer artificial lake (the largest in the world) and the 3rd largest river in Brazil (the Sao Francisco). In an effort to avoid using agricultural medicines, the vines are fertilized with organic matter created on the farm and little or no pesticides are used since pests do not live in such an arid region. It has taken 20 years of trial and error, but the quality of the grapes is now very high and is competitive on the world market. Because of climate and location, harvesting is done year round which increases the productivity of the land. The farm managers have found that married women make the best workers and have the highest level of productivity. Age at 1st marriage averages 24-25, compared with 15-16 for unemployed women in the same area. The fertility rate averages 50% of that for unemployed women in the same area. Agricultural development offers the best opportunity for the women of developing countries. It can pay a high wage, reduce fertility, and replant desert areas.

  3. Desempenho de cultivares de melão rendilhado em função do sistema de cultivo Performance of net melon cultivars depending on the cultivation system

    Directory of Open Access Journals (Sweden)

    Pablo F Vargas

    2008-06-01

    Full Text Available Objetivou-se com este trabalho avaliar cinco cultivares de melão rendilhado em dois sistemas de cultivo quanto às características produtivas. O experimento foi instalado em casa de vegetação na UNESP-FCAV, em Jaboticabal-SP, de novembro/05 a fevereiro/06. O delineamento experimental utilizado foi de blocos ao acaso, em esquema fatorial 5 x 2, com quatro repetições. Os fatores avaliados foram cinco híbridos de melão rendilhado (Maxim, Bônus nº2, Shinju 200, Fantasy e Louis e dois sistemas de cultivo (no solo e em substrato a base de fibra da casca de coco. Após a colheita, foram avaliados a produção por planta (kg planta-1; diâmetro transversal (DTF e longitudinal (DLF do fruto, em mm; índice de formato do fruto (IFF; diâmetro transversal (DTL e longitudinal (DLL do lóculo, em mm; índice de formato do lóculo (IFL; diâmetro de inserção do pedúnculo (DIP, em mm; e espessura do mesocarpo (EM, em mm. Não se verificou interação significativa entre os fatores avaliados. O cultivo em substrato proporcionou maior produtividade por planta em relação ao cultivo no solo (2,51 e 1,52 kg planta-1, respectivamente, tendo a cultivar Fantasy (2,44 kg planta-1 o melhor desempenho entre as cultivares, não diferindo de Louis e Maxim. Para as características DIP, DTL e EM, foram verificados melhores desempenhos em plantas cultivadas em substrato. Para as características DTF, DLF, IFF e DLL não foram encontradas diferenças entre os sistemas de cultivo. Assim, o cultivo em substrato se destacou em relação ao cultivo no solo, tendo a cultivar Fantasy apresentado melhor desempenho comparada a Shinju 200 e Bônus nº2.In this study the productive characteristics of five net melon cultivars, using two different cultivation systems were evaluated. The study was conducted in a greenhouse from November/05 to February/06. The experiments were carried out using randomized complete block design with a 5 x 2 factorial scheme and four

  4. Micrometeorological principles of protected cultivation

    Science.gov (United States)

    Protected cultivation is a broad term commonly used among producers of specialty crops. Techniques can range from complex fixed structures to field site selection, to straightforward cultural practices in the field. This introduction to the ASHS workshop "Protected cultivation for fruit crops" consi...

  5. Pilot-scale continuous recycling of growth medium for the mass culture of a halotolerant Tetraselmis sp. in raceway ponds under increasing salinity: a novel protocol for commercial microalgal biomass production.

    Science.gov (United States)

    Fon Sing, S; Isdepsky, A; Borowitzka, M A; Lewis, D M

    2014-06-01

    The opportunity to recycle microalgal culture medium for further cultivation is often hampered by salinity increases from evaporation and fouling by dissolved and particulate matter. In this study, the impact of culture re-use after electro-flocculation of seawater-based medium on growth and biomass productivity of the halotolerant green algal strain Tetraselmis sp., MUR 233, was investigated in pilot-scale open raceway ponds over 5months. Despite a salinity increase from 5.5% to 12% (w/v) NaCl, Tetraselmis MUR 233 grown on naturally DOC-enriched recycled medium produced 48-160% more ash free dry weight (AFDW) biomass daily per unit pond area than when grown on non-recycled medium. A peak productivity of 37.5±3.1gAFDWm(-2)d(-1) was reached in the recycled medium upon transition from ∼14% to ∼7% NaCl. The combination of high biomass-yielding mixotrophic growth under high salinity has been proven to be a successful sustainable cultivation strategy. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Salt Effect on the Antioxidant Activity of Red Microalgal Sulfated Polysaccharides in Soy-Bean Formula

    Directory of Open Access Journals (Sweden)

    Ariela Burg

    2015-10-01

    Full Text Available Sulfated polysaccharides produced by microalgae, which are known to exhibit various biological activities, may potentially serve as natural antioxidant sources. To date, only a few studies have examined the antioxidant bioactivity of red microalgal polysaccharides. In this research, the effect of different salts on the antioxidant activities of two red microalgal sulfated polysaccharides derived from Porphyridium sp. and Porphyridium aerugineum were studied in a soy bean-based infant milk formula. Salt composition and concentration were both shown to affect the polysaccharides’ antioxidant activity. It can be postulated that the salt ions intefer with the polysaccharide chains’ interactions and alter their structure, leading to a new three-dimensional structure that better exposes antiooxidant sites in comparison to the polysaccharide without salt supplement. Among the cations that were studied, Ca2+ had the strongest enhancement effect on antioxidant activities of both polysaccharides. Understanding the effect of salts on polysaccharides’ stucture, in addition to furthering knowledge on polysaccharide bioactivities, may also shed light on the position of the antioxidant active sites.

  7. Salt Effect on the Antioxidant Activity of Red Microalgal Sulfated Polysaccharides in Soy-Bean Formula.

    Science.gov (United States)

    Burg, Ariela; Oshrat, Levy-Ontman

    2015-10-20

    Sulfated polysaccharides produced by microalgae, which are known to exhibit various biological activities, may potentially serve as natural antioxidant sources. To date, only a few studies have examined the antioxidant bioactivity of red microalgal polysaccharides. In this research, the effect of different salts on the antioxidant activities of two red microalgal sulfated polysaccharides derived from Porphyridium sp. and Porphyridium aerugineum were studied in a soy bean-based infant milk formula. Salt composition and concentration were both shown to affect the polysaccharides' antioxidant activity. It can be postulated that the salt ions intefer with the polysaccharide chains' interactions and alter their structure, leading to a new three-dimensional structure that better exposes antiooxidant sites in comparison to the polysaccharide without salt supplement. Among the cations that were studied, Ca(2+) had the strongest enhancement effect on antioxidant activities of both polysaccharides. Understanding the effect of salts on polysaccharides' stucture, in addition to furthering knowledge on polysaccharide bioactivities, may also shed light on the position of the antioxidant active sites.

  8. A Review on the Assessment of Stress conditions for Simultaneous Production of Microalgal Lipids and Carotenoids

    Directory of Open Access Journals (Sweden)

    Amritpreet kaur Minhas

    2016-05-01

    Full Text Available Microalgal species are potential resource of both biofuels and high-value metabolites, and their production is growth dependent. Growth parameters can be screened for the selection of novel microalgal species that produce molecules of interest. In this context our review confirms that, autotrophic and heterotrophic organisms have demonstrated a dual potential, namely the ability to produce lipids as well as value-added products (particularly carotenoids under influence of various physico-chemical stresses on microalgae. Some species of microalgae can synthesize, besides some pigments, very-long-chain polyunsaturated fatty acids (VL-PUFA,>20C such as docosahexaenoic acid and eicosapentaenoic acid, those have significant applications in food and health. Producing value-added by-products in addition to biofuels, fatty acid methyl esters (FAME, and lipids has the potential to improve microalgae-based biorefineries by employing either the autotrophic or the heterotrophic mode, which could be an offshoot of biotechnology. The review considers the potential of microalgae to produce a range of products and indicates future directions for developing suitable criteria for choosing novel isolates through bioprospecting large gene pool of microalga obtained from various habitats and climatic conditions.

  9. A Review on the Assessment of Stress Conditions for Simultaneous Production of Microalgal Lipids and Carotenoids

    Science.gov (United States)

    Minhas, Amritpreet K.; Hodgson, Peter; Barrow, Colin J.; Adholeya, Alok

    2016-01-01

    Microalgal species are potential resource of both biofuels and high-value metabolites, and their production is growth dependent. Growth parameters can be screened for the selection of novel microalgal species that produce molecules of interest. In this context our review confirms that, autotrophic and heterotrophic organisms have demonstrated a dual potential, namely the ability to produce lipids as well as value-added products (particularly carotenoids) under influence of various physico-chemical stresses on microalgae. Some species of microalgae can synthesize, besides some pigments, very-long-chain polyunsaturated fatty acids (VL-PUFA,>20C) such as docosahexaenoic acid and eicosapentaenoic acid, those have significant applications in food and health. Producing value-added by-products in addition to biofuels, fatty acid methyl esters (FAME), and lipids has the potential to improve microalgae-based biorefineries by employing either the autotrophic or the heterotrophic mode, which could be an offshoot of biotechnology. The review considers the potential of microalgae to produce a range of products and indicates future directions for developing suitable criteria for choosing novel isolates through bioprospecting large gene pool of microalga obtained from various habitats and climatic conditions. PMID:27199903

  10. Production of Microalgal Lipids as Biodiesel Feedstock with Fixation of CO2 by Chlorella vulgaris

    Directory of Open Access Journals (Sweden)

    Qiao Hu

    2014-01-01

    Full Text Available The global warming and shortage of energy are two critical problems for human social development. CO2 mitigation and replacing conventional diesel with biodiesel are effective routes to reduce these problems. Production of microalgal lipids as biodiesel feedstock by a freshwater microalga, Chlorella vulgaris, with the ability to fixate CO2 is studied in this work. The results show that nitrogen deficiency, CO2 volume fraction and photoperiod are the key factors responsible for the lipid accumulation in C. vulgaris. With 5 % CO2, 0.75 g/L of NaNO3 and 18:6 h of light/dark cycle, the lipid content and overall lipid productivity reached 14.5 % and 33.2 mg/(L·day, respectively. Furthermore, we proposed a technique to enhance the microalgal lipid productivity by activating acetyl-CoA carboxylase (ACCase with an enzyme activator. Citric acid and Mg2+ were found to be efficient enzyme activators of ACCase. With the addition of 150 mg/L of citric acid or 1.5 mmol/L of MgCl2, the lipid productivity reached 39.1 and 38.0 mg/(L·day, respectively, which was almost twofold of the control. This work shows that it is practicable to produce lipids by freshwater microalgae that can fixate CO2, and provides a potential route to solving the global warming and energy shortage problems.

  11. Microalgal-biochar immobilized complex: A novel efficient biosorbent for cadmium removal from aqueous solution.

    Science.gov (United States)

    Shen, Ying; Li, Huan; Zhu, Wenzhe; Ho, Shih-Hsin; Yuan, Wenqiao; Chen, Jianfeng; Xie, Youping

    2017-11-01

    The feasibility of the bioremediation of cadmium (Cd) using microalgal-biochar immobilized complex (MBIC) was investigated. Major operating parameters (e.g., pH, biosorbent dosage, initial Cd(II) concentration and microalgal-biochar ratio) were varied to compare the treatability of viable algae (Chlorella sp.), biochar and MBIC. The biosorption isotherms obtained by using algae or biochar were found to have satisfactory Langmuir predictions, while the best fitting adsorption isotherm model for MBIC was the Sips model. The maximum Cd(II) adsorption capacity of MBIC with a Chlorella sp.: biochar ratio of 2:3 (217.41mgg -1 ) was higher than that of Chlorella sp. (169.92mgg -1 ) or biochar (95.82mgg -1 ) alone. The pseudo-second-order model fitted the biosorption process of MBIC well (R 2 >0.999). Moreover, zeta potential, SEM and FTIR studies revealed that electrostatic attraction, ion exchange and surface complexation were the main mechanisms responsible for Cd removal when using MBIC. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Enhanced the energy outcomes from microalgal biomass by the novel biopretreatment

    International Nuclear Information System (INIS)

    He, Shuai; Fan, Xiaolei; Luo, Shengjun; Katukuri, Naveen Reddy; Guo, Rongbo

    2017-01-01

    Highlights: • The micro-aerobic pretreatment was used to improve energy yield of Chlorella sp. • The Bacillus licheniformis was confirmed to damage the cell wall of microalgae. • Obtained energy from Chlorella sp. was improved by 12.3%. • Pretreatment time was decreased from 60 h to 24 h. • The VS degradation efficiency was increased from 75.7% to 82.1%. - Abstract: Microalgae have been considered as one of the most promising biomass for the generation of biofuels. The anaerobic digestion (AD) has been proved to be a promising technique to transfer the microalgal biomass into biofuels. Previous study demonstrated that anaerobic pretreatment of microalgae biomass by Bacillus licheniformis could improve methane production. In this study micro-aerobic bio-pretreatment of microalgal biomass by the facultative anaerobic bacteria Bacillus licheniformis was invested with different loads of oxygen supplied. The bio-hydrogen and biomethane productions were tested to calculate total energy outcomes. The transmission electron microscope (TEM) photographs suggested that the novel micro-aerobic bio-pretreatment (MBP) could effectively damage the firm cell wall of algal cells. The processing time of the novel method (24 h) was less than the previous anaerobic pretreatment (60 h). Results showed that the group with 5 mL oxygen/g VS fed had the highest total energy outcomes, which was 17.6% higher than that of the anaerobic pretreatment.

  13. Comparative assessment of various lipid extraction protocols and optimization of transesterification process for microalgal biodiesel production.

    Science.gov (United States)

    Mandal, Shovon; Patnaik, Reeza; Singh, Amit Kumar; Mallick, Nirupama

    2013-01-01

    Biodiesel, using microalgae as feedstocks, is being explored as the most potent form of alternative diesel fuel for sustainable economic development. A comparative assessment of various protocols for microalgal lipid extraction was carried out using five green algae, six blue-green algae and two diatom species treated with different single and binary solvents both at room temperature and using a soxhlet. Lipid recovery was maximum with chloroform-methanol in the soxhlet extractor. Pretreatments ofbiomass, such as sonication, homogenization, bead-beating, lyophilization, autoclaving, microwave treatment and osmotic shock did not register any significant rise in lipid recovery. As lipid recovery using chloroform-methanol at room temperature demonstrated a marginally lower value than that obtained under the soxhlet extractor, on economical point of view, the former is recommended for microalgal total lipid extraction. Transesterification process enhances the quality of biodiesel. Experiments were designed to determine the effects of catalyst type and quantity, methanol to oil ratio, reaction temperature and time on the transesterification process using response surface methodology. Fatty acid methyl ester yield reached up to 91% with methanol:HCl:oil molar ratio of 82:4:1 at 65 degrees C for 6.4h reaction time. The biodiesel yield relative to the weight of the oil was found to be 69%.

  14. Microalgal process-monitoring based on high-selectivity spectroscopy tools: status and future perspectives.

    Science.gov (United States)

    Podevin, Michael; Fotidis, Ioannis A; Angelidaki, Irini

    2018-08-01

    Microalgae are well known for their ability to accumulate lipids intracellularly, which can be used for biofuels and mitigate CO 2 emissions. However, due to economic challenges, microalgae bioprocesses have maneuvered towards the simultaneous production of food, feed, fuel, and various high-value chemicals in a biorefinery concept. On-line and in-line monitoring of macromolecules such as lipids, proteins, carbohydrates, and high-value pigments will be more critical to maintain product quality and consistency for downstream processing in a biorefinery to maintain and valorize these markets. The main contribution of this review is to present current and prospective advances of on-line and in-line process analytical technology (PAT), with high-selectivity - the capability of monitoring several analytes simultaneously - in the interest of improving product quality, productivity, and process automation of a microalgal biorefinery. The high-selectivity PAT under consideration are mid-infrared (MIR), near-infrared (NIR), and Raman vibrational spectroscopies. The current review contains a critical assessment of these technologies in the context of recent advances in software and hardware in order to move microalgae production towards process automation through multivariate process control (MVPC) and software sensors trained on "big data". The paper will also include a comprehensive overview of off-line implementations of vibrational spectroscopy in microalgal research as it pertains to spectral interpretation and process automation to aid and motivate development.

  15. Detailing the start-up and microalgal growth performance of a full-scale photobioreactor operated with bioindustrial wastewater

    DEFF Research Database (Denmark)

    Podevin, Michael Paul Ambrose; Fotidis, Ioannis; De Francisci, Davide

    2017-01-01

    were tested. Bioindustrial WW medium was treated with ultrafiltration and was demonstrated to be a viable microalgal growth medium at large scale; however, further treatment is needed for the removal of fecal coliform to meet drinking water standards. The fresh water mesophilic algae Chlorella...

  16. Enzymatic transesterification of microalgal oil from Chlorella vulgaris ESP-31 for biodiesel synthesis using immobilized Burkholderia lipase.

    Science.gov (United States)

    Tran, Dang-Thuan; Yeh, Kuei-Ling; Chen, Ching-Lung; Chang, Jo-Shu

    2012-03-01

    An indigenous microalga Chlorella vulgaris ESP-31 grown in an outdoor tubular photobioreactor with CO(2) aeration obtained a high oil content of up to 63.2%. The microalgal oil was then converted to biodiesel by enzymatic transesterification using an immobilized lipase originating from Burkholderia sp. C20. The conversion of the microalgae oil to biodiesel was conducted by transesterification of the extracted microalgal oil (M-I) and by transesterification directly using disrupted microalgal biomass (M-II). The results show that M-II achieved higher biodiesel conversion (97.3 wt% oil) than M-I (72.1 wt% oil). The immobilized lipase worked well when using wet microalgal biomass (up to 71% water content) as the oil substrate. The immobilized lipase also tolerated a high methanol to oil molar ratio (>67.93) when using the M-II approach, and can be repeatedly used for six cycles (or 288 h) without significant loss of its original activity. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Adubação complementar para a mexeriqueira 'Rio' em sistema de cultivo orgânico Complementary fertilization to willowleaf mandarim in organic cultivation system

    Directory of Open Access Journals (Sweden)

    Fillipe S. Marini

    2011-06-01

    Full Text Available Objetivou-se com este trabalho avaliar os efeitos da adubação complementar com o biofertilizante Supermagro, a urina de vaca e a manipueira na produção e nos teores de nutrientes nas folhas da mexeriqueira (Citrus deliciosa Tenore cv. Rio em sistema de cultivo orgânico. O delineamento experimental adotado foi o de blocos casualizados, com cinco repetições. Todas as plantas foram adubadas com esterco bovino e os tratamentos aplicados foram complementares a essa adubação. Foram constituídos dez tratamentos obtidos pelos tipos de adubo e por seu modo de aplicação (via solo, via pulverizações foliares ou ambos e uma testemunha. A produção foi avaliada nas safras de 2006 e 2007 e os teores de nutrientes nas folhas, em 2005, 2006 e 2007. A adubação complementar não influenciou a produção de frutos. As aplicações de urina de vaca via solo, com ou sem aplicação foliar, e da manipueira, independentemente do modo de aplicação, contribuíram para elevar os teores de S nas folhas. O Supermagro aplicado via solo aumentou os teores de B nas folhas e, quando aplicado via foliar, aumentou os teores de Zn.The aim of this work was to evaluate the effect of complementary fertilization with the biofertilizer Supermagro, cow urine and cassava wastewater in the production and levels of nutrients in the leaves of willowleaf mandarim 'Rio' (Citrus deliciosa Tenore in organic cultivation system. The experimental design used was the randomized blocks, with five replications. All plants were fertilized with cow manure and the applied treatments were complementary to this fertilization. Ten treatments were constituted, by fertilizer types and by modes of application (soil, foliar spray or both plus a control. The fruits were harvested in 2006 and 2007. The nutrient content in leaves was determined in 2005, 2006 and 2007. The complementary fertilization did not affect the fruit production. However, the cow urine applied on soil, with or without

  18. Wirelessly powered submerged-light illuminated photobioreactors for efficient microalgae cultivation

    DEFF Research Database (Denmark)

    Murray, Alexandra Marie; Fotidis, Ioannis; Isenschmid, Alex

    2017-01-01

    A novel submerged-light photobioreactor (SL-PBR) with free-floating, wireless internal light sources powered by near-field resonant inductive coupling was investigated using a quick (Chlorella vulgaris) and a slow (Haematococcus pluvialis) growing microalgal species. During testing of the SL......, respectively. Thus, the wireless internal light source was proven to be up to fivefold more effective light delivery system compared to the conventional illumination system. Meanwhile, it was discovered that some of the internal light sources had ceased to function, which might have caused underestimation...

  19. Soil protection through almond tree cultivation

    International Nuclear Information System (INIS)

    Garcia, C.; Hernandez, T.; Moreno, J. L.; Bastida, F.; Masciandaro, G.; Mennone, C.; Ceccanti, B.

    2009-01-01

    Most threat to soil are particularly severe in areas with steps slopes and suffering dry periods followed by heavy rain such as the Mediterranean regions. Severity is aggravated by lacking or inappropriate farming systems. Therefore the objective of this work was to demonstrate that land management based on cultivation of new varieties of local crops (almond trees) suited to these conditions may result in a sustainable system to prevent soil degradation. (Author)

  20. Improving protein production of indigenous microalga Chlorella vulgaris FSP-E by photobioreactor design and cultivation strategies.

    Science.gov (United States)

    Chen, Chun-Yen; Lee, Po-Jen; Tan, Chung Hong; Lo, Yung-Chung; Huang, Chieh-Chen; Show, Pau Loke; Lin, Chih-Hung; Chang, Jo-Shu

    2015-06-01

    Fish meal is currently the major protein source for commercial aquaculture feed. Due to its unstable supply and increasing price, fish meal is becoming more expensive and its availability is expected to face significant challenges in the near future. Therefore, feasible alternatives to fish meal are urgently required. Microalgae have been recognized as the most promising candidates to replace fish meal because the protein composition of microalgae is similar to fish meal and the supply of microalgae-based proteins is sustainable. In this study, an indigenous microalga (Chlorella vulgaris FSP-E) with high protein content was selected, and its feasibility as an aquaculture protein source was explored. An innovative photobioreactor (PBR) utilizing cold cathode fluorescent lamps as an internal light source was designed to cultivate the FSP-E strain for protein production. This PBR could achieve a maximum biomass and protein productivity of 699 and 365 mg/L/day, respectively, under an optimum urea and iron concentration of 12.4 mM and 90 μM, respectively. In addition, amino acid analysis of the microalgal protein showed that up to 70% of the proteins in this microalgal strain consist of indispensable amino acids. Thus, C. vulgaris FSP-E appears to be a viable alternative protein source for the aquaculture industry. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Effect of the nutritional status of semi-continuous microalgal cultures on the productivity and biochemical composition of Brachionus plicatilis.

    Science.gov (United States)

    Ferreira, Martiña; Seixas, Pedro; Coutinho, Paula; Fábregas, Jaime; Otero, Ana

    2011-12-01

    The rotifer Brachionus plicatilis was cultured using the microalga Isochrysis aff. galbana clone T-ISO as feed. T-ISO was cultured semi-continuously with daily renewal rates of 10%, 20%, 30%, 40%, and 50% of the volume of cultures. The increase of renewal rate led to increasing nutrient and light availability in microalgal cultures, which caused differences in the biochemical composition of microalgal biomass. Growth rate, individual dry weight, organic content, and biomass productivity of rotifer cultures increased in response to higher growth rate in T-ISO cultures. Rotifer growth rate showed a strong negative correlation (R² = 0.90) with the C/N ratio of microalgal biomass. Rotifer dry weight was also affected by nutrient availability of T-ISO cultures, increasing up to 50% from nutrient-limited to nutrient-sufficient conditions. Consequently, biomass productivity of rotifer cultures increased more than twofold with the increase of renewal rate of T-ISO cultures. Rotifer organic content underwent the same trend of total dry weight. Maximum content of polyunsaturated fatty acids was reached in rotifers fed T-ISO from the renewal rate of 40%, with percentages of docosahexaenoic acid (22:6ω-3, DHA) and eicosapentaenoic acid (20:5ω-3, EPA) of 11% and 5% of total fatty acids, respectively. Selecting the most appropriate conditions for microalgal culture can therefore enhance the nutritive quality of microalgal biomass, resulting in a better performance of filter feeders and their nutrient content, and may constitute a useful tool to improve the rearing of fish larvae and other aquaculture organisms that require live feed in some or all the stages of their life cycle.

  2. Cultivating Peace: Conflict and Collaboration in Natural Resource ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Cultivating Peace presents original case studies from Africa, Asia, and Latin America, ... experience on moving from conflict to collaborative modes of management. ... public health, and health systems research relevant to the emerging crisis.

  3. Fatty acids from high rate algal pond's microalgal biomass and osmotic stress effects.

    Science.gov (United States)

    Drira, Neila; Dhouibi, Nedra; Hammami, Saoussen; Piras, Alessandra; Rosa, Antonella; Porcedda, Silvia; Dhaouadi, Hatem

    2017-11-01

    The extraction of oil from a wild microalgae biomass collected from a domestic wastewater treatment facility's high rate algal pond (HRAP) was investigated. An experiment plan was used to determine the most efficient extraction method, the optimal temperature, time and solvent system based on total lipids yield. Microwave-assisted extraction was the most efficient method whether in n-hexane or in a mixture of chloroform/methanol compared to Soxhlet, homogenization, and ultrasounds assisted extractions. This same wild biomass was cultivated in a photobioreactor (PBR) and the effect of osmotic stress was studied. The lipids extraction yield after 3days of stress increased by more than four folds without any significant loss of biomass, however, the quality of extracted total lipids in terms of saturated, monounsaturated and polyunsaturated fatty acids was not affected by salinity change in the culture medium. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Using straw hydrolysate to cultivate Chlorella pyrenoidosa for high-value biomass production and the nitrogen regulation for biomass composition.

    Science.gov (United States)

    Zhang, Tian-Yuan; Wang, Xiao-Xiong; Wu, Yin-Hu; Wang, Jing-Han; Deantes-Espinosa, Victor M; Zhuang, Lin-Lan; Hu, Hong-Ying; Wu, Guang-Xue

    2017-11-01

    Heterotrophic cultivation of Chlorella pyrenoidosa based on straw substrate was proposed as a promising approach in this research. The straw pre-treated by ammonium sulfite method was enzymatically hydrolyzed for medium preparation. The highest intrinsic growth rate of C. pyrenoidosa reached to 0.097h -1 in hydrolysate medium, which was quicker than that in glucose medium. Rising nitrogen concentration could significantly increase protein content and decrease lipid content in biomass, meanwhile fatty acids composition kept stable. The highest protein and lipid content in microalgal biomass reached to 62% and 32% under nitrogen excessive and deficient conditions, respectively. Over 40% of amino acids and fatty acids in biomass belonged to essential amino acids (EAA) and essential fatty acids (EFA), which were qualified for high-value uses. This research revealed the rapid biomass accumulation property of C. pyrenoidosa in straw hydrolysate medium and the effectiveness of nitrogen regulation to biomass composition at heterotrophic condition. Copyright © 2017. Published by Elsevier Ltd.

  5. Fate of H2S during the cultivation of Chlorella sp. deployed for biogas upgrading.

    Science.gov (United States)

    González-Sánchez, Armando; Posten, Clemens

    2017-04-15

    The H 2 S may play a key role in the sulfur cycle among the biogas production by the anaerobic digestion of wastes and the biogas upgrading by a microalgae based technology. The biogas is upgraded by contacting with slightly alkaline aqueous microalgae culture, then CO 2 and H 2 S are absorbed. The dissolved H 2 S could limit or inhibit the microalgae growth. This paper evaluated the role of dissolved H 2 S and other sulfured byproducts under prevailing biogas upgrading conditions using a microalgal technology. At initial stages of batch cultivation the growth of Chlorella sp. was presumably inhibited by dissolved H 2 S. After 2 days, the sulfides were oxidized mainly by oxic chemical reactions to sulfate, which was later rapidly assimilated by Chlorella sp., allowing high growing rates. The fate of H 2 S during the microalgae cultivation at pH > 8.5 was assessed by a mathematical model where the pentasulfide, thiosulfate and sulfite were firstly produced and converted finally to sulfate for posterior assimilation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Microalgae cultivation for bioenergy production using wastewaters from a municipal WWTP as nutritional sources.

    Science.gov (United States)

    Cho, Sunja; Lee, Nakyeong; Park, Seonghwan; Yu, Jaecheul; Luong, Thanh Thao; Oh, You-Kwan; Lee, Taeho

    2013-03-01

    In order to reduce input cost for microalgal cultivation, we investigated the feasibility of wastewater taken from a municipal WWTP in Busan, Korea as wastewater nutrients. The wastewaters used in this study were the effluent from a primary settling tank (PS), the effluent from an anaerobic digestion tank (AD), the conflux of wastewaters rejected from sludge-concentrate tanks and dewatering facilities (CR), and two combined wastewaters of AD:PS (10:90, v/v) and AD:CR (10:90, v/v). Chlorella sp. ADE5, which was isolated from the AD, was selected for the feasibility test. The highest biomass production (3.01 g-dry cell weight per liter) of the isolate was obtained with the combined wastewater ADCR, and it was 1.72 times higher than that with BG 11 medium. Interestingly, the cells cultivated with wastewater containing PS wastewater were easily separated from the culture and improved lipid content, especially oleic acid content, in their cells. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Qualidade do tomate de mesa cultivado nos sistemas convencional e orgânico Quality of tomatoes cultivated in the organic and conventional cropping systems

    Directory of Open Access Journals (Sweden)

    Sila Mary Rodrigues Ferreira

    2010-03-01

    Full Text Available A presença dos produtos orgânicos nas gôndolas das grandes redes de supermercados indica que existe um potencial de mercado para esses produtos, no entanto poucas são as informações técnico-científicas sobre eles. Em razão disso, o presente trabalho teve como objetivo determinar a qualidade do tomate de mesa cultivado nos sistemas convencional (SC e orgânico (SO comercializado na Região Metropolitana de Curitiba. As amostras foram avaliadas pela massa, peso específico, cinzas, sólidos totais, sólidos solúveis totais, acidez titulável total, relação sólidos solúveis totais/acidez titulável total, pH, vitamina C, nitratos, nitritos, multirresíduos, benzimidazóis e ditiocarbamatos. Os resultados da análise físico-química mostraram que somente na umidade os tomates não apresentaram diferença significativa ao nível de 5% quando comparados pelo Teste de Tukey. Em relação à análise toxicológica, não foram detectados multirresíduos e benzimidazóis até os limites de 0,04 mg.kg-1 e 0,1 mg.kg-1 de carbendazim, respectivamente. Nos resíduos de pesticidas do grupo químico ditiocarbamatos, foi identificado 0,01 mg.kg-1 (CS2 nas amostras de SC3 e SC4 do tomate de mesa cultivado no sistema convencional, abaixo do limite máximo recomendado (LMR de 2,0 mg.kg-1 (CS2 de mancozebe.The presence of organic products in the aisles of big supermarket chains indicates a market potential for these products. However, there is little technical and scientific information. Thus, the objective of this work was to determine the quality of tomatoes grown under conventional (CS and organic (OS systems, on sale in the metropolitan area of Curitiba, Brazil. Samples were evaluated in terms of mass, specific weight, ash, total solids, total soluble solids, total titratable acidity, total soluble solids/total titratable acidity ratio, pH, vitamin C, nitrates, nitrites, multiresidues. There were no significant differences between conventional and

  8. On microalgal settlements and the sluggish development of marine biofouling in Port Blair waters, Andamans.

    Science.gov (United States)

    Eashwar, M; Nallathambi, T; Kuberaraj, K

    2008-01-01

    Settlement of microalgae was investigated on Perspex, aluminium and zinc coupons immersed in Port Blair Bay waters for over 3 months. Commencement of fouling was exceptionally slow, and few microalgae were found until 14 days. Settlement occurred thereafter, and 47 microalgal species contributed to the fouling. The dominant forms belonged to the genera Navicula and Nitzschia, whereas Coscinodiscus eccentricus, Gyrosigma balticum and Trichodesmium erythraeum also accounted for high proportions of the settlements. The dominance of Nitzschia sigma was particularly marked on zinc coupons, suggesting an ability by the organism to resist toxicity. Settlement of both centric and pennate diatoms was observed in the early and mid periods, and absolute dominance of the pennate diatoms subsequently. The fouling mass was low even after 103 days, and it is speculated that strong ultraviolet radiation might be the prime reason for the sluggish development of marine biofouling in these oceanic island waters.

  9. Effect of nitrogen regime on microalgal lipid production during mixotrophic growth with glycerol.

    Science.gov (United States)

    Paranjape, Kiran; Leite, Gustavo B; Hallenbeck, Patrick C

    2016-08-01

    Mixotrophic growth of microalgae to boost lipid production is currently under active investigation. Such a process could be of practical importance if a cheap source of organic carbon, such as waste glycerol from biodiesel production, could be used. Several previous studies have already demonstrated that this carbon source can be used by different indigenous strains of microalgae. In this study it is shown that different nitrogen limitation strategies can be applied to further increase lipid production during growth with glycerol. In one strategy, cultures were grown in nitrogen replete medium and then resuspended in nitrogen free medium. In a second strategy, cultures were grown with different initial concentrations of nitrate. Lipid production by the two microalgal strains used, Chlorella sorokiniana (PCH02) and Chlorella vulgaris (PCH05), was shown to be boosted by strategies of nitrogen limitation, but they responded differently to how nitrogen limitation was imposed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Three-Dimensional Simulation of Ultrasound-Induced Microalgal Cell Disruption.

    Science.gov (United States)

    Wang, M; Yuan, W; Hale, Andy

    2016-03-01

    The three-dimensional distribution (x, y, and z) of ultrasound-induced microalgal cell disruption in a sonochemical reactor was predicted by solving the Helmholtz equation using a three-dimensional acoustic module in the COMSOL Multiphysics software. The simulated local ultrasound pressure at any given location (x, y, and z) was found to correlate with cell disruption of a freshwater alga, Scenedesmus dimorphus, represented by the change of algal cell particle/debris concentration, chlorophyll-a fluorescence density (CAFD), and Nile red stained lipid fluorescence density (LFD), which was also validated by the model reaction of potassium iodide oxidation (the Weissler reaction). Furthermore, the effect of ultrasound power intensity and processing duration on algal cell disruption was examined to address the limitation of the model.

  11. Biodiesel production by direct transesterification of microalgal biomass with co-solvent.

    Science.gov (United States)

    Zhang, Yan; Li, Ya; Zhang, Xu; Tan, Tianwei

    2015-11-01

    In this study, a direct transesterification process using 75% ethanol and co-solvent was studied to reduce the energy consumption of lipid extraction process and improve the conversion yield of the microalgae biodiesel. The addition of a certain amount of co-solvent (n-hexane is most preferable) was required for the direct transesterification of microalgae biomass. With the optimal reaction condition of n-hexane to 75% ethanol volume ratio 1:2, mixed solvent dosage 6.0mL, reaction temperature 90°C, reaction time 2.0h and catalyst volume 0.6mL, the direct transesterification process of microalgal biomass resulted in a high conversion yield up to 90.02±0.55wt.%. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Effect of laser radiation on the cultivation rate of the microalga Chlorella sorokiniana as a source of biofuel

    Science.gov (United States)

    Politaeva, N.; Smyatskaya, Y.; Slugin, V.; Toumi, A.; Bouabdelli, M.

    2018-01-01

    This article studies the influence of laser radiation on the growth of micro-algal biomass of Chlorella sorokiniana. The composition of nutrient medium and the effect the laser beam (2 and 5 cm diameter, 1, 5, 10, 15 and 20 minutes exposure time) for accelerated cultivation of microalgal biomass were studied. The source of laser radiation (LR) was a helium-neon laser with a nominal output power of 1.6 mW and a wavelength of 0.63 μm. The greatest increase in biomass was observed when LR was applied to a suspension of microalga Chlorella sorokiniana with a beam of 5 cm diameter for a time of 10, 15 and 20 minutes. The results of the microscopic study of the microalga cells show a significant increase in the number of cells after an exposure to LR with a beam diameter of 5 cm in diameter. These cells were characterized by a large vacuole, a thickened lipid shell and a large accumulation of metabolites prone to agglutination. This study proposed to obtain valuable components (lipids, carotenoids, and pectin) from the obtained biomass by extraction method and to use the residual biomass formed wastes, after the extraction of valuable components, as a co-substrate for anaerobic digestion to produce biogas. The composition of biogas consists mainly of methane and carbon dioxide. Methane is recommended to be used for economic needs in supplying the whole process with heat and electricity. The carbon dioxide formed during fermentation and after combustion of methane for energy production, is planned to be used as a carbon source in the cultivation of Chlorella sorokiniana for photoautotrophic biomass production.

  13. Cultivo da levedura Phaffia rhodozyma (Xanthophyllomyces dendrorhous em processo descontínuo alimentado para produção de astaxantina Cultivation of Phaffia rhodozyma (Xanthophyllomyces dendrorhous yeast in discontinuous system to obtain astaxanthin

    Directory of Open Access Journals (Sweden)

    Miriam Blümel Chociai

    2002-12-01

    Full Text Available A levedura Phaffia rhodozyma, produtora de astaxantina, pigmento carotenóide largamente empregado na aqüicultura de peixes e crustáceos, pode ser eficientemente cultivada num meio de cultura de baixo custo, à base de caldo de cana diluído 1:10 e uréia a 1 g/L. No entanto, a produção de biomassa e a formação do carotenóide sofrem a inibição pelo substrato (efeito "Crabtree", limitando desta forma a utilização do caldo de cana com concentrações da fonte de carbono superiores a 20 g/L, importante consideração na produção industrial de astaxantina. No presente trabalho, o cultivo da levedura P. rhodozyma foi realizado em processo descontínuo alimentado, no qual se obteve produtividade volumétrica de 0,024 mg astaxantina/L.h. em relação aos 0,013 mg astaxantina/L.h. obtidos no cultivo controle, que não sofreu alimentação da fonte de carbono.The yeast Phaffia rhodozyma produces astaxanthin, a carotenoid pigment widely applied in fish and crustaceous cultivation. This yeast can be efficiently cultured in a low cost medium, sugar cane broth diluted 1:10 and supplemented with 1 g/L urea. However, the biomass and astaxanthin production undergo inhibition by the substrate (Crabtree effect, limiting the utilization of sugar cane broth up to 20 g/L total sugar concentration. Therefore, this effect must be considered during the industrial production of astaxanthin. In the present work, using fed batch system to cultivate P. rhodozyma we were able to obtain 0.024 mg astaxanthin/l.h compared to 0.013 mg astaxanthin/l.h obtained by the discontinuous cultivation system.

  14. Biodiversity, evolution and adaptation of cultivated crops.

    Science.gov (United States)

    Vigouroux, Yves; Barnaud, Adeline; Scarcelli, Nora; Thuillet, Anne-Céline

    2011-05-01

    The human diet depends on very few crops. Current diversity in these crops is the result of a long interaction between farmers and cultivated plants, and their environment. Man largely shaped crop biodiversity from the domestication period 12,000 B.P. to the development of improved varieties during the last century. We illustrate this process through a detailed analysis of the domestication and early diffusion of maize. In smallholder agricultural systems, farmers still have a major impact on crop diversity today. We review several examples of the major impact of man on current diversity. Finally, biodiversity is considered to be an asset for adaptation to current environmental changes. We describe the evolution of pearl millet in West Africa, where average rainfall has decreased over the last forty years. Diversity in cultivated varieties has certainly helped this crop to adapt to climate variation. Copyright © 2011 Académie des sciences. Published by Elsevier SAS. All rights reserved.

  15. Fungal cultivation on glass-beads

    DEFF Research Database (Denmark)

    Droce, Aida; Sørensen, Jens Laurids; Giese, Henriette

    Transcription of various bioactive compounds and enzymes are dependent on fungal cultivation method. In this study we cultivate Fusarium graminearum and Fusarium solani on glass-beads with liquid media in petri dishes as an easy and inexpensive cultivation method, that resembles in secondary...... metabolite production to agar-cultivation but with an easier and more pure RNA-extraction of total fungal mycelia....

  16. Greenhouse Gas Emissions and Global Warming Potential of Traditional and Diversified Tropical Rice Rotation Systems including Impacts of Upland Crop Management Practices i.e. Mulching and Inter-crop Cultivation

    Science.gov (United States)

    Janz, Baldur; Weller, Sebastian; Kraus, David; Wassmann, Reiner; Butterbach-Bahl, Klaus; Kiese, Ralf

    2016-04-01

    Paddy rice cultivation is increasingly challenged by irrigation water scarcity, while at the same time changes in demand (e.g. changes in diets or increasing demand for biofuels) will feed back on agricultural practices. These factors are changing traditional cropping patterns from flooded double-rice systems to the introduction of well-aerated upland crop systems in the dry season. Emissions of methane (CH4) are expected to decrease, while emissions of nitrous oxide (N2O) will increase and soil organic carbon (SOC) stocks will most likely be volatilized in the form of carbon dioxide (CO2). We measured greenhouse gas (GHG) emissions at the International Rice Research Institute (IRRI) in the Philippines to provide a comparative assessment of the global warming potentials (GWP) as well as yield scaled GWPs of different crop rotations and to evaluate mitigation potentials or risks of new management practices i.e. mulching and inter-crop cultivation. New management practices of mulching and intercrop cultivation will also have the potential to change SOC dynamics, thus can play the key role in contributing to the GWP of upland cropping systems. To present, more than three years of continuous measurement data of CH4 and N2O emissions in double-rice cropping (R-R) and paddy rice rotations diversified with either maize (R-M) or aerobic rice (R-A) in upland cultivation have been collected. Introduction of upland crops in the dry season reduced irrigation water use and CH4 emissions by 66-81% and 95-99%, respectively. Moreover, for practices including upland crops, CH4 emissions in the subsequent wet season with paddy rice were reduced by 54-60%. Although annual N2O emissions increased twice- to threefold in the diversified systems, the strong reduction of CH4 led to a significantly lower (pbalance but also with regard to soil fertility. New upland crop management practices where first implemented during land-preparation for dry season (July) 2015 where i) 6t/ha rice straw

  17. Systems and economic analysis of microalgae ponds for conversion of CO{sub 2} to biomass. Quarterly technical progress report, September 1993--December 1993

    Energy Technology Data Exchange (ETDEWEB)

    Benemann, J.R.; Oswald, W.J.

    1994-01-15

    This report provides an economic analysis and feasibility study for the utilization by microalgal systems of carbon dioxide generated from coal-fired power plants. The resulting biomass could be a fuel substitute for fossil fuels.

  18. Investigation of the photochemical changes of chlorogenic acids induced by ultraviolet light in model systems and in agricultural practice with Stevia rebaudiana cultivation as an example.

    Science.gov (United States)

    Karaköse, Hande; Jaiswal, Rakesh; Deshpande, Sagar; Kuhnert, Nikolai

    2015-04-08

    Mono- and diacyl chlorogenic acids undergo photochemical trans-cis isomerization under ultraviolet (UV) irradiation. The photochemical equilibrium composition was established for eight selected derivatives. In contrast to all other dicaffeoylquinic acid derivatives, cynarin (1,3-dicaffeoylquinic acid) undergoes a [2 + 2] photochemical cycloaddition reaction, constituting a first example of Schmidt's law in a natural product family. The relevance of photochemical isomerization in agricultural practice was investigated using 120 samples of Stevia rebaudiana leave samples grown under defined cultivation conditions. Ratios of cis to trans chlorogenic acids were determined in leaf samples and correlated with climatic and harvesting conditions. The data indicate a clear correlation between the formation of cis-caffeoyl derivatives and sunshine hours prior to harvesting and illustrate the relevance of UV exposure to plant material affecting its phytochemical composition.

  19. Molasses wastewater treatment and lipid production at low temperature conditions by a microalgal mutant Scenedesmus sp. Z-4

    OpenAIRE

    Ma, Chao; Wen, Hanquan; Xing, Defeng; Pei, Xuanyuan; Zhu, Jiani; Ren, Nanqi; Liu, Bingfeng

    2017-01-01

    Background Simultaneous wastewater treatment and lipid production by oleaginous microalgae show great potential to alleviate energy shortage and environmental pollution, because they exhibit tremendous advantages over traditional activated sludge. Currently, most research on wastewater treatment by microalgal are carried out at optimized temperature conditions (25?35??C), but no information about simultaneous wastewater treatment and lipid production by microalgae at low temperatures has been...

  20. Simultaneous improvement in production of microalgal biodiesel and high-value alpha-linolenic acid by a single regulator acetylcholine

    OpenAIRE

    Parsaeimehr, Ali; Sun, Zhilan; Dou, Xiao; Chen, Yi-Feng

    2015-01-01

    Background Photoautotrophic microalgae are a promising avenue for sustained biodiesel production, but are compromised by low yields of biomass and lipids at present. We are developing a chemical approach to improve microalgal accumulation of feedstock lipids as well as high-value alpha-linolenic acid which in turn might provide a driving force for biodiesel production. Results We demonstrate the effectiveness of the small bioactive molecule ?acetylcholine? on accumulation of biomass, total li...

  1. Biodiesel production from microalgal isolates of southern Pakistan and quantification of FAMEs by GC-MS/MS analysis

    Directory of Open Access Journals (Sweden)

    Musharraf Syed

    2012-12-01

    Full Text Available Abstract Background Microalgae have attracted major interest as a sustainable source for biodiesel production on commercial scale. This paper describes the screening of six microalgal species, Scenedesmus quadricauda, Scenedesmus acuminatus, Nannochloropsis sp., Anabaena sp., Chlorella sp. and Oscillatoria sp., isolated from fresh and marine water resources of southern Pakistan for biodiesel production and the GC-MS/MS analysis of their fatty acid methyl esters (FAMEs. Results Growth rate, biomass productivity and oil content of each algal species have been investigated under autotrophic condition. Biodiesel was produced from algal oil by acid catalyzed transesterification reaction and resulting fatty acid methyl esters (FAMEs content was analyzed by GC/MS. Fatty acid profiling of the biodiesel, obtained from various microalgal oils showed high content of C-16:0, C-18:0, cis-Δ9C-18:1, cis-Δ11C-18:1 (except Scenedesmus quadricauda and 10-hydroxyoctadecanoic (except Scenedesmus acuminatus. Absolute amount of C-14:0, C-16:0 and C-18:0 by a validated GC-MS/MS method were found to be 1.5-1.7, 15.0-42.5 and 4.2-18.4 mg/g, respectively, in biodiesel obtained from various microalgal oils. Biodiesel was also characterized in terms of cetane number, kinematic viscosity, density and higher heating value and compared with the standard values. Conclusion Six microalgae of local origin were screened for biodiesel production. A method for absolute quantification of three important saturated fatty acid methyl esters (C-14, C-16 and C-18 by gas chromatography-tandem mass spectrometry (GC-MS/MS, using multiple reactions monitoring (MRM mode, was employed for the identification and quantification of biodiesels obtained from various microalgal oils. The results suggested that locally found microalgae can be sustainably harvested for the production of biodiesel. This offers the tremendous economic opportunity for an energy-deficient nation.

  2. Two-step microalgal biodiesel production using acidic catalyst generated from pyrolysis-derived bio-char

    International Nuclear Information System (INIS)

    Dong, Tao; Gao, Difeng; Miao, Chao; Yu, Xiaochen; Degan, Charles; Garcia-Pérez, Manuel; Rasco, Barbara; Sablani, Shyam S.; Chen, Shulin

    2015-01-01

    Highlights: • Highly active catalyst was prepared using bio-char co-produced in Auger pyrolysis. • Catalyst inhibitors in crude oil were effectively removed by a practical refinery process. • Free fatty acids (FFA) content in refined microalgal oil was reduced to less than 0.5%. • A total fatty acid methyl ester (FAME) yield of 99% was obtained via a two-step process. • The inexpensive bio-char catalyst is superior to Amberlyst-15 in pre-esterification. - Abstract: An efficient process for biodiesel production from fast-refined microalgal oil was demonstrated. A low cost catalyst prepared from pyrolysis-derived bio-char, was applied in pre-esterification to reduce free fatty acid (FFA) content. Results showed that the bio-char catalyst was highly active in esterification; however, the performance of the catalyst significantly reduced when crude microalgal oil was used as feedstock. To solve the problem caused by catalyst-fouling, a fast and scalable crude oil refinery procedure was carried out to remove chlorophyll and phospholipids that might degrade the catalyst and the quality of biodiesel. The activity and reusability of bio-char catalyst were remarkably improved in the fast-refined oil. FFA content in the refined microalgal oil was reduced to less than 0.5% after pre-esterification. The bio-char catalyst could be reused for 10 cycles without dramatic loss in activity. The pre-esterification fits the first-order kinetic reaction with activation energy of 42.16 kJ/mol. The activity of bio-char catalyst was superior to commercial Amberlyst-15 under the same reaction condition. A total fatty acid methyl ester (FAME, namely biodiesel) yield of 99% was obtained following the second-step CaO-catalyzed transesterification. The cost-effective bio-char catalyst has great potential for biodiesel production using feedstocks having high FFA content.

  3. Use of waste material in cultivation substrates

    Directory of Open Access Journals (Sweden)

    Petr Salaš

    2004-01-01

    Full Text Available Gardeners' practical experience and experimental work prove the affirmation that the used substrate is a very important base for the production of quality nursery products. It is important to emphasis the complexity and synergy of all factors influencing the ecosystem and there mutual relations. Physical, chemical and biological properties do not separately affect the growth and development of plants. In addition, the relations are not statical but differ in relation with other factors changes. This article is dealing with the possibility to use waste material from timber processing in cultivation substrates. The large scale use of such substrates would enable people to reach a relative independence from peat substrates, of which the global reserve is gradually decreasing.Our research activities focus on the use of bark. The basic problems of a bark substrate are easy dehydration and unbalanced nutrition of trees and shrubs. The suggested and experimented cultivation technology solves these problems. It is based on the cultivation of woody species in bark substrates, using modern irrigation systems, slow release fertilisers (Silvamix Forte and special soil conditioners (TerraCottem. This technology was tested on the following species of trees and shrubs: Malus and Buxus.

  4. Cultivation Of Deep Subsurface Microbial Communities

    Science.gov (United States)

    Obrzut, Natalia; Casar, Caitlin; Osburn, Magdalena R.

    2018-01-01

    The potential habitability of surface environments on other planets in our solar system is limited by exposure to extreme radiation and desiccation. In contrast, subsurface environments may offer protection from these stressors and are potential reservoirs for liquid water and energy that support microbial life (Michalski et al., 2013) and are thus of interest to the astrobiology community. The samples used in this project were extracted from the Deep Mine Microbial Observatory (DeMMO) in the former Homestake Mine at depths of 800 to 2000 feet underground (Osburn et al., 2014). Phylogenetic data from these sites indicates the lack of cultured representatives within the community. We used geochemical data to guide media design to cultivate and isolate organisms from the DeMMO communities. Media used for cultivation varied from heterotrophic with oxygen, nitrate or sulfate to autotrophic media with ammonia or ferrous iron. Environmental fluid was used as inoculum in batch cultivation and strains were isolated via serial transfers or dilution to extinction. These methods resulted in isolating aerobic heterotrophs, nitrate reducers, sulfate reducers, ammonia oxidizers, and ferric iron reducers. DNA sequencing of these strains is underway to confirm which species they belong to. This project is part of the NASA Astrobiology Institute Life Underground initiative to detect and characterize subsurface microbial life; by characterizing the intraterrestrials, the life living deep within Earth’s crust, we aim to understand the controls on how and where life survives in subsurface settings. Cultivation of terrestrial deep subsurface microbes will provide insight into the survival mechanisms of intraterrestrials guiding the search for these life forms on other planets.

  5. cultivated Curcuma longa seedlings

    African Journals Online (AJOL)

    Ufuoma Uwerhiavwo

    2016-08-10

    Aug 10, 2016 ... content through flow cytometry, utilizing two reference standards, green ... Key words: Turmeric, micropropagation, flow cytometry, vegetal anatomy. ...... A computer statistical analysis system. ... Science 220(4601):1049-1051.

  6. Bioreactor design and implementation strategies for the cultivation of filamentous fungi and the production of fungal metabolites: from traditional methods to engineered systems

    Directory of Open Access Journals (Sweden)

    Musoni, M.

    2015-01-01

    Full Text Available The production of fungal metabolites and conidia at an industrial scale requires an adequate yield at relatively low cost. To this end, many factors are examined and the design of the bioreactor to be used for the selected product takes a predominant place in the analysis. One approach to addressing the issue is to integrate the scaling-up procedure according to the biological characteristics of the microorganism considered, i.e. in our case filamentous fungi. Indeed, the scaling-up procedure is considered as one of the major bottlenecks in fermentation technology, mainly due to the near impossibility of reproducing the ideal conditions obtained in small reactors designed for research purposes when transposing them to a much larger production scale. The present review seeks to make the point regarding the bioreactor design and its implementation for cultivation of filamentous fungi and the production of fungal metabolites according to different developmental stages of fungi of industrial interest. Solid-state (semi-solid, submerged, fermentation and biofilm reactors are analyzed. The different bioreactor designs used for these three processes are also described at the technological level.

  7. Cultivation and uses of cucurbits

    Science.gov (United States)

    Cultivated cucurbits have spread through trade and exploration from their respective Old and New World centers of origin to the six arable continents and are important in local, regional and world trade. Cucumber (Cucumis sativus L.), melon (Cucumis melo L.), pumpkin, squash and gourd (Cucurbita spp...

  8. Cultivating Audiences: Taming, Teaching, Transforming

    Science.gov (United States)

    Nicolucci, Sandra

    2010-01-01

    Satisfying and successful school concerts require an active, empathic, and cooperative partnership between performers and audience members. As music educators work to prepare artful, dignified, and confident performers, "audiences" for these performers must be cultivated just as purposefully. Concertgoers can be motivated to consume school…

  9. Continuous cultivation of photosynthetic microorganisms: Approaches, applications and future trends.

    Science.gov (United States)

    Fernandes, Bruno D; Mota, Andre; Teixeira, Jose A; Vicente, Antonio A

    2015-11-01

    The possibility of using photosynthetic microorganisms, such as cyanobacteria and microalgae, for converting light and carbon dioxide into valuable biochemical products has raised the need for new cost-efficient processes ensuring a constant product quality. Food, feed, biofuels, cosmetics and pharmaceutics are among the sectors that can profit from the application of photosynthetic microorganisms. Biomass growth in a photobioreactor is a complex process influenced by multiple parameters, such as photosynthetic light capture and attenuation, nutrient uptake, photobioreactor hydrodynamics and gas-liquid mass transfer. In order to optimize productivity while keeping a standard product quality, a permanent control of the main cultivation parameters is necessary, where the continuous cultivation has shown to be the best option. However it is of utmost importance to recognize the singularity of continuous cultivation of cyanobacteria and microalgae due to their dependence on light availability and intensity. In this sense, this review provides comprehensive information on recent breakthroughs and possible future trends regarding technological and process improvements in continuous cultivation systems of microalgae and cyanobacteria, that will directly affect cost-effectiveness and product quality standardization. An overview of the various applications, techniques and equipment (with special emphasis on photobioreactors) in continuous cultivation of microalgae and cyanobacteria are presented. Additionally, mathematical modeling, feasibility, economics as well as the applicability of continuous cultivation into large-scale operation, are discussed. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Quantitative Assessment of Microalgae Biomass and Lipid Stability Post-Cultivation

    Energy Technology Data Exchange (ETDEWEB)

    Napan, Katerine; Christianson, Tyler; Voie, Kristen; Quinn, Jason C., E-mail: jason.quinn@usu.edu [Department of Mechanical and Aerospace Engineering, Utah State University, Logan, UT (United States)

    2015-04-15

    Processing of microalgal biomass to biofuels and other products requires the removal of the culture from a well-controlled growth system to a containment or preprocessing step at non-ideal growth conditions, such as darkness, minimal gas exchange, and fluctuating temperatures. The conditions and the length of time between harvest and processing will impact microalgal metabolism, resulting in biomass and lipid degradation. This study experimentally investigates the impact of time and temperature on Nannochloropsis salina harvested from outdoor plate photobioreactors. The impact of three temperatures, 4, 40, or 70°C, on biomass and lipid content (as fatty acid methyl esters) of the harvested microalgae was evaluated over a 156 h time period. Results show that for N. salina, time and temperature are key factors that negatively impact biomass and lipid yields. The temperature of 70°C resulted in the highest degradation with the overall biofuel potential reduced by 30% over 156 h. Short time periods, 24 h, and low temperatures are shown to have little effect on the harvested biomass.

  11. Establishing Comprehensive Experiment System of Microbiological Technologies and Cultivating Undergraduate' s Professional Scientific Literacy%构建微生物学技术综合实验体系 培养大学生科研素养

    Institute of Scientific and Technical Information of China (English)

    韩国民; 沈玲; 张明; 徐世红(编、校)

    2012-01-01

    为了培养学生实验设计能力,提高学生的实验基本功,以学生感兴趣的酒精制作工艺的各个环节为实验内容,构建了微生物学技术综合实验体系。在项目实施过程中将酒精制作工艺分解成酵母菌筛选、菌种鉴定、细胞固定化及酒精发酵等4个模块,在各个模块中融入多种基本实验技术,形成一个系统的综合性实验项目。本项目的实施有利于培养学生实验设计能力、数据分析能力和论文写作能力,以提高学生的科研素养。%In order to cultivate student' s ability of design experiment and enhance their techniques, we selected the manufacture craft of alcohol which was favored by students as the contents of experiment to establish comprehensive experiment system of microbiological technology. The manufacture craft was divided into four parts, i.e. selection of yeasts, identification, immobilization of cells and alcoholic fermentation. A large number of basic techniques were integrated into the four parts and formed a comprehensive experiment system. The experiment system is beneficial to cultivate student' s ability of design experiment, data analytical ability and academic writing capacity for cuhivating and enhancing students' professional scientific literacy.

  12. Cultivating the Glocal Garden

    Directory of Open Access Journals (Sweden)

    Matthijs Hisschemoller

    2016-04-01

    Full Text Available This paper addresses the question under which conditions small-scale urban agriculture (UA initiatives can accelerate a sustainability transition of the global food system. It develops the notion of a glocal garden, a large number of likeminded local initiatives with a global impact and forms of worldwide collaboration. Taking a transition perspective, the glocal garden, producing vegetables and fruits, is a niche that has to overcome barriers to compete with the dominant food regime. Since a sustainability transition restructures (policy sectors, institutional domains including knowledge systems, the paper explores which innovations are needed for the glocal garden to succeed. It discusses the glocal garden as an environmental, a social, an economic and a global project. As an environmental project, the glocal garden will link sustainable production of food with renewable energy production. As a social project, it will be organized into a consumers’ cooperative. As an economic project, it will strive for profit, increasing the yield in a sustainable manner. As a global project, it will enhance collaboration between local cooperatives in the North and the South, as well as with rural agriculture. Under these conditions, the glocal garden can develop into a power, able to resist a possible future food regime that splits societies, in terms of quality standards and food products, into haves and have-nots.

  13. Sustainable intensification of cultivated pastures using multiple ...

    African Journals Online (AJOL)

    rangeland and wildlife parks) for guidelines to implementing this approach in cultivated pasture. In rangeland or natural grassland ... Keywords: animal production, biodiversity, cultivated pastures, foraging ecology, plant–herbivore interactions ...

  14. Disponibilidade de água do solo ao milho cultivado sob sistemas de semeadura direta e preparo convencional Water availability to maize plants cultivated under no-tillage and conventional tillage systems

    Directory of Open Access Journals (Sweden)

    Mirta Teresinha Petry

    2007-06-01

    Full Text Available O objetivo deste trabalho foi quantificar o armazenamento, a disponibilidade e a extração de água no solo por plantas de milho irrigadas e submetidas a déficit hídrico terminal, cultivadas sob sistema de semeadura direta e preparo convencional. Foram realizados dois experimentos durante os anos agrícolas de 1999/00 e 2000/01, em área experimental do Departamento de Engenharia Rural da Universidade Federal de Santa Maria. Utilizou-se o delineamento experimental inteiramente casualizado, fatorial, com quatro repetições. Foram utilizados dois manejos da água de irrigação (fator A: irrigado e déficit hídrico terminal (plantas de milho foram submetidas a déficit hídrico terminal a partir dos 27 dias após a emergência; e dois sistemas de cultivo (fator B: semeadura direta e preparo convencional. Nas parcelas irrigadas, irrigações foram feitas para elevar o conteúdo de água no solo ao limite superior de disponibilidade de água às plantas, sempre que a evapotranspiração máxima acumulada da cultura do milho atingia 25 mm. O conteúdo de água no solo foi medido em três leituras semanais, para determinação da extração de água pelas plantas e disponibilidade de água às plantas de milho. Os resultados indicaram que a disponibilidade de água às plantas de milho foi similar nos sistemas semeadura direta e preparo convencional, em ambos os anos agrícolas avaliados. Plantas de milho cultivadas em preparo convencional extraíram maior quantidade de água, em ambos os anos, em relação à semeadura direta.The aim objective of this study was to quantify the soil water storage, plant-available water and extraction of soil water by corn plants under irrigation and terminal drought. Plants were cultivated under no-tillage and conventional tillage systems. Two experiments were conducted in the 1999/00 and 2000/01 growing season on an experimental field of the Agricultural Engineering Department of the Federal University of Santa

  15. Soil carbon and nitrogen mineralization under different tillage systems and Permanent Groundcover cultivation between Orange trees Mineralização do carbono e nitrogênio sob diferentes preparos de solo e coberturas permanentes intercalares em pomar de laranjeira

    Directory of Open Access Journals (Sweden)

    Elcio Liborio Balota

    2011-06-01

    Full Text Available The objective of this work was to evaluate the alterations in carbon and nitrogen mineralization due to different soil tillage systems and groundcover species for intercropped orange trees. The experiment was established in an Ultisol soil (Typic Paleudults originated from Caiuá sandstone in northwestern of the state of Paraná, Brazil, in an area previously cultivated with pasture (Brachiaria humidicola. Two soil tillage systems were evaluated: conventional tillage (CT in the entire area and strip tillage (ST with a 2-m width, each with different groundcover vegetation management systems. The citrus cultivar utilized was the 'Pera' orange (Citrus sinensis grafted onto a 'Rangpur' lime rootstock. The soil samples were collected at a 0-15-cm depth after five years of experiment development. Samples were collected from under the tree canopy and from the inter-row space after the following treatments: (1 CT and annual cover crop with the leguminous Calopogonium mucunoides; (2 CT and perennial cover crop with the leguminous peanut Arachis pintoi; (3 CT and evergreen cover crop with Bahiagrass Paspalum notatum; (4 CT and cover crop with spontaneous B. humidicola grass vegetation; and (5 ST and maintenance of the remaining grass (pasture of B. humidicola. The soil tillage systems and different groundcover vegetation influenced the C and N mineralization, both under the tree canopy and in the inter-row space. The cultivation of B. humidicola under strip tillage provided higher potential mineralization than the other treatments in the inter-row space. Strip tillage increased the C and N mineralization compared to conventional tillage. The grass cultivation increased the C and N mineralization when compared to the others treatments cultivated in the inter-row space.No presente trabalho, foi avaliada a mineralização do Carbono e Nitrogênio devido ao cultivo intercalar de diferentes coberturas permanentes em pomar de laranjeira. O experimento foi

  16. Anaerobic co-digestion of coffee husks and microalgal biomass after thermal hydrolysis.

    Science.gov (United States)

    Passos, Fabiana; Cordeiro, Paulo Henrique Miranda; Baeta, Bruno Eduardo Lobo; de Aquino, Sergio Francisco; Perez-Elvira, Sara Isabel

    2018-04-01

    Residual coffee husks after seed processing may be better profited if bioconverted into energy through anaerobic digestion. This process may be improved by implementing a pretreatment step and by co-digesting the coffee husks with a more liquid biomass. In this context, this study aimed at evaluating the anaerobic co-digestion of coffee husks with microalgal biomass. For this, both substrates were pretreated separately and in a mixture for attaining 15% of total solids (TS), which was demonstrated to be the minimum solid content for pretreatment of coffee husks. The results showed that the anaerobic co-digestion presented a synergistic effect, leading to 17% higher methane yield compared to the theoretical value of both substrates biodegraded separately. Furthermore, thermal hydrolysis pretreatment increased coffee husks anaerobic biodegradability. For co-digestion trials, the highest values were reached for pretreatment at 120 °C for 60 min, which led to 196 mLCH 4 /gVS and maximum methane production rate of 0.38 d -1 . Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Microalgal biofactories: a promising approach towards sustainable omega-3 fatty acid production

    Directory of Open Access Journals (Sweden)

    Adarme-Vega T

    2012-07-01

    Full Text Available Abstract Omega-3 fatty acids eicosapentaenoic acid (EPA and docosahexaenoic acid (DHA provide significant health benefits and this has led to an increased consumption as dietary supplements. Omega-3 fatty acids EPA and DHA are found in animals, transgenic plants, fungi and many microorganisms but are typically extracted from fatty fish, putting additional pressures on global fish stocks. As primary producers, many marine microalgae are rich in EPA (C20:5 and DHA (C22:6 and present a promising source of omega-3 fatty acids. Several heterotrophic microalgae have been used as biofactories for omega-3 fatty acids commercially, but a strong interest in autotrophic microalgae has emerged in recent years as microalgae are being developed as biofuel crops. This paper provides an overview of microalgal biotechnology and production platforms for the development of omega-3 fatty acids EPA and DHA. It refers to implications in current biotechnological uses of microalgae as aquaculture feed and future biofuel crops and explores potential applications of metabolic engineering and selective breeding to accumulate large amounts of omega-3 fatty acids in autotrophic microalgae.

  18. Dynamic metabolic modeling of heterotrophic and mixotrophic microalgal growth on fermentative wastes.

    Directory of Open Access Journals (Sweden)

    Caroline Baroukh

    2017-06-01

    Full Text Available Microalgae are promising microorganisms for the production of numerous molecules of interest, such as pigments, proteins or triglycerides that can be turned into biofuels. Heterotrophic or mixotrophic growth on fermentative wastes represents an interesting approach to achieving higher biomass concentrations, while reducing cost and improving the environmental footprint. Fermentative wastes generally consist of a blend of diverse molecules and it is thus crucial to understand microalgal metabolism in such conditions, where switching between substrates might occur. Metabolic modeling has proven to be an efficient tool for understanding metabolism and guiding the optimization of biomass or target molecule production. Here, we focused on the metabolism of Chlorella sorokiniana growing heterotrophically and mixotrophically on acetate and butyrate. The metabolism was represented by 172 metabolic reactions. The DRUM modeling framework with a mildly relaxed quasi-steady-state assumption was used to account for the switching between substrates and the presence of light. Nine experiments were used to calibrate the model and nine experiments for the validation. The model efficiently predicted the experimental data, including the transient behavior during heterotrophic, autotrophic, mixotrophic and diauxic growth. It shows that an accurate model of metabolism can now be constructed, even in dynamic conditions, with the presence of several carbon substrates. It also opens new perspectives for the heterotrophic and mixotrophic use of microalgae, especially for biofuel production from wastes.

  19. Composition and Quantitation of Microalgal Lipids by ERETIC 1H NMR Method

    Directory of Open Access Journals (Sweden)

    Angelo Fontana

    2013-09-01

    Full Text Available Accurate characterization of biomass constituents is a crucial aspect of research in the biotechnological application of natural products. Here we report an efficient, fast and reproducible method for the identification and quantitation of fatty acids and complex lipids (triacylglycerols, glycolipids, phospholipids in microalgae under investigation for the development of functional health products (probiotics, food ingredients, drugs, etc. or third generation biofuels. The procedure consists of extraction of the biological matrix by modified Folch method and direct analysis of the resulting material by proton nuclear magnetic resonance (1H NMR. The protocol uses a reference electronic signal as external standard (ERETIC method and allows assessment of total lipid content, saturation degree and class distribution in both high throughput screening of algal collection and metabolic analysis during genetic or culturing studies. As proof of concept, the methodology was applied to the analysis of three microalgal species (Thalassiosira weissflogii, Cyclotella cryptica and Nannochloropsis salina which drastically differ for the qualitative and quantitative composition of their fatty acid-based lipids.

  20. Use of Cellulolytic Marine Bacteria for Enzymatic Pretreatment in Microalgal Biogas Production

    Science.gov (United States)

    Muñoz, Camilo; Hidalgo, Catalina; Zapata, Manuel; Jeison, David; Riquelme, Carlos

    2014-01-01

    In this study, we designed and evaluated a microalgal pretreatment method using cellulolytic bacteria that naturally degrades microalgae in their native habitat. Bacterial strains were isolated from each of two mollusk species in a medium containing 1% carboxymethyl cellulose agar. We selected nine bacterial strains that had endoglucanase activity: five strains from Mytilus chilensis, a Chilean mussel, and four strains from Mesodesma donacium, a clam found in the Southern Pacific. These strains were identified phylogenetically as belonging to the genera Aeromonas, Pseudomonas, Chryseobacterium, and Raoultella. The cellulase-producing capacities of these strains were characterized, and the degradation of cell walls in Botryococcus braunii and Nannochloropsis gaditana was tested with “whole-cell” cellulolytic experiments. Aeromonas bivalvium MA2, Raoultella ornithinolytica MA5, and Aeromonas salmonicida MC25 degraded B. braunii, and R. ornithinolytica MC3 and MA5 degraded N. gaditana. In addition, N. gaditana was pretreated with R. ornithinolytica strains MC3 and MA5 and was then subjected to an anaerobic digestion process, which increased the yield of methane by 140.32% and 158.68%, respectively, over that from nonpretreated microalgae. Therefore, a “whole-cell” cellulolytic pretreatment can increase the performance and efficiency of biogas production. PMID:24795376

  1. Biotechnological Screening of Microalgal and Cyanobacterial Strains for Biogas Production and Antibacterial and Antifungal Effects

    Directory of Open Access Journals (Sweden)

    Opayi Mudimu

    2014-05-01

    Full Text Available Microalgae and cyanobacteria represent a valuable natural resource for the generation of a large variety of chemical substances that are of interest for medical research, can be used as additives in cosmetics and food production, or as an energy source in biogas plants. The variety of potential agents and the use of microalgae and cyanobacteria biomass for the production of these substances are little investigated and not exploited for the market. Due to the enormous biodiversity of microalgae and cyanobacteria, they hold great promise for novel products. In this study, we investigated a large number of microalgal and cyanobacterial strains from the Culture Collection of Algae at Göttingen University (SAG with regard to their biomass and biogas production, as well antibacterial and antifungal effects. Our results demonstrated that microalgae and cyanobacteria are able to generate a large number of economically-interesting substances in different quantities dependent on strain type. The distribution and quantity of some of these components were found to reflect phylogenetic relationships at the level of classes. In addition, between closely related species and even among multiple isolates of the same species, the productivity may be rather variable.

  2. Application of Fungicides and Microalgal Phenolic Extracts for the Direct Control of Fumonisin Contamination in Maize.

    Science.gov (United States)

    Scaglioni, Priscila Tessmer; Blandino, Massimo; Scarpino, Valentina; Giordano, Debora; Testa, Giulio; Badiale-Furlong, Eliana

    2018-05-16

    Fungicides and, for the first time, microalgal phenolic extracts (MPE) from Spirulina sp. and Nannochloropsis sp. were applied on maize culture media under field conditions to evaluate their ability to minimize Fusarium species development and fumonisin production. An in vitro assay against F. verticillioides was carried out using maize grains as the culture medium. An open-field experiment was carried out in Northwest Italy under natural infection conditions. The compared treatments were factorial combinations of two insecticide treatments (an untreated control and pyrethroid, used against European Corn Borer), four antifungal treatments (an untreated control, MPE from Spirulina sp., MPE from Nannochloropsis sp., and a synthetic fungicide), and two timings of the application of the antifungal compounds (at maize flowering and at the milk stage). The MPE compounds were capable of inhibiting fumonisin production in vitro more efficiently than tebuconazole. Insecticide application reduced the infection by Fusarium species and subsequent fumonisin contamination. However, fumonisins in maize fields were not significantly controlled by either fungicide or MPE application.

  3. Bioremoval Capacity Of Phenol By Green Micro-Algal And Fungal Species Isolated From Dry Environment

    Directory of Open Access Journals (Sweden)

    Abdullah T. Al-fawwaz

    2015-08-01

    Full Text Available Phenol is an organic hazardous pollutant that exerts toxic effects on living cells at relatively at low concentrations. Moreover accumulation of phenol exhibit toxicity towards the biotic components of the environment. Phenol bioremoval is a very useful approach to clean up the residual phenol from the environment. This study aims at isolating green microalgae and fungi from local dry environment to test their ability to remove phenol. Subsequently two green microalgal species have been isolated and identified as Desmodesmus sp. and Chlamydomonas sp.. Also two fungal species have been isolated and identified as Rhizopus sp. and Mucor sp. Phenol bioremoval capacity as well as the effects of some physicochemical factors on the bioremoval process were then studied. These factors include initial phenol concentration contact time and the synergistic effect Desmodesmus sp. and Rhizopus sp. on the bioremoval process. Both microalgae and fungi showed phenol bioremoval capacity. The highest phenol removal percentage among algae was found 75 by Desmodesmus sp. after 25 days at 25 mgL while the highest phenol removal percentage among fungi was found 86 by Rhizopus sp. after 25 days at 100 mgL. Bioremoval of phenol by the consortium Desmodesmus sp. and Rhizopus sp. was found to be 95 at the phenol concentration 25 mgL.

  4. Biological Soil Crusts of Arctic Svalbard—Water Availability as Potential Controlling Factor for Microalgal Biodiversity

    Directory of Open Access Journals (Sweden)

    Nadine Borchhardt

    2017-08-01

    Full Text Available In the present study the biodiversity of biological soil crusts (BSCs formed by phototrophic organisms were investigated on Arctic Svalbard (Norway. These communities exert several important ecological functions and constitute a significant part of vegetation at high latitudes. Non-diatom eukaryotic microalgal species of BSCs from 20 sampling stations around Ny-Ålesund and Longyearbyen were identified by morphology using light microscopy, and the results revealed a high species richness with 102 species in total. 67 taxa belonged to Chlorophyta (31 Chlorophyceae and 36 Trebouxiophyceae, 13 species were Streptophyta (11 Klebsormidiophyceae and two Zygnematophyceae and 22 species were Ochrophyta (two Eustigmatophyceae and 20 Xanthophyceae. Surprisingly, Klebsormidium strains belonging to clade G (Streptophyta, which were so far described from Southern Africa, could be determined at 5 sampling stations. Furthermore, comparative analyses of Arctic and Antarctic BSCs were undertaken to outline differences in species composition. In addition, a pedological analysis of BSC samples included C, N, S, TP (total phosphorus, and pH measurements to investigate the influence of soil properties on species composition. No significant correlation with these chemical soil parameters was confirmed but the results indicated that pH might affect the BSCs. In addition, a statistically significant influence of precipitation on species composition was determined. Consequently, water availability was identified as one key driver for BSC biodiversity in Arctic regions.

  5. Biological Soil Crusts of Arctic Svalbard-Water Availability as Potential Controlling Factor for Microalgal Biodiversity.

    Science.gov (United States)

    Borchhardt, Nadine; Baum, Christel; Mikhailyuk, Tatiana; Karsten, Ulf

    2017-01-01

    In the present study the biodiversity of biological soil crusts (BSCs) formed by phototrophic organisms were investigated on Arctic Svalbard (Norway). These communities exert several important ecological functions and constitute a significant part of vegetation at high latitudes. Non-diatom eukaryotic microalgal species of BSCs from 20 sampling stations around Ny-Ålesund and Longyearbyen were identified by morphology using light microscopy, and the results revealed a high species richness with 102 species in total. 67 taxa belonged to Chlorophyta (31 Chlorophyceae and 36 Trebouxiophyceae), 13 species were Streptophyta (11 Klebsormidiophyceae and two Zygnematophyceae) and 22 species were Ochrophyta (two Eustigmatophyceae and 20 Xanthophyceae). Surprisingly, Klebsormidium strains belonging to clade G (Streptophyta), which were so far described from Southern Africa, could be determined at 5 sampling stations. Furthermore, comparative analyses of Arctic and Antarctic BSCs were undertaken to outline differences in species composition. In addition, a pedological analysis of BSC samples included C, N, S, TP (total phosphorus), and pH measurements to investigate the influence of soil properties on species composition. No significant correlation with these chemical soil parameters was confirmed but the results indicated that pH might affect the BSCs. In addition, a statistically significant influence of precipitation on species composition was determined. Consequently, water availability was identified as one key driver for BSC biodiversity in Arctic regions.

  6. Hydrology Affects Environmental and Spatial Structuring of Microalgal Metacommunities in Tropical Pacific Coast Wetlands.

    Directory of Open Access Journals (Sweden)

    Carmen Rojo

    Full Text Available The alternating climate between wet and dry periods has important effects on the hydrology and therefore on niche-based processes of water bodies in tropical areas. Additionally, assemblages of microorganism can show spatial patterns, in the form of a distance decay relationship due to their size or life form. We aimed to test spatial and environmental effects, modulated by a seasonal flooding climatic pattern, on the distribution of microalgae in 30 wetlands of a tropical dry forest region: the Pacific coast of Costa Rica and Nicaragua. Three surveys were conducted corresponding to the beginning, the highest peak, and the end of the hydrological year during the wet season, and species abundance and composition of planktonic and benthic microalgae was determined. Variation partitioning analysis (as explained by spatial distance or environmental factors was applied to each seasonal dataset by means of partial redundancy analysis. Our results show that microalgal assemblages were structured by spatial and environmental factors depending on the hydrological period of the year. At the onset of hydroperiod and during flooding, neutral effects dominated community dynamics, but niche-based local effects resulted in more structured algal communities at the final periods of desiccating water bodies. Results suggest that climate-mediated effects on hydrology can influence the relative role of spatial and environmental factors on metacommunities of microalgae. Such variability needs to be accounted in order to describe accurately community dynamics in tropical coastal wetlands.

  7. dEMBF: A Comprehensive Database of Enzymes of Microalgal Biofuel Feedstock.

    Science.gov (United States)

    Misra, Namrata; Panda, Prasanna Kumar; Parida, Bikram Kumar; Mishra, Barada Kanta

    2016-01-01

    Microalgae have attracted wide attention as one of the most versatile renewable feedstocks for production of biofuel. To develop genetically engineered high lipid yielding algal strains, a thorough understanding of the lipid biosynthetic pathway and the underpinning enzymes is essential. In this work, we have systematically mined the genomes of fifteen diverse algal species belonging to Chlorophyta, Heterokontophyta, Rhodophyta, and Haptophyta, to identify and annotate the putative enzymes of lipid metabolic pathway. Consequently, we have also developed a database, dEMBF (Database of Enzymes of Microalgal Biofuel Feedstock), which catalogues the complete list of identified enzymes along with their computed annotation details including length, hydrophobicity, amino acid composition, subcellular location, gene ontology, KEGG pathway, orthologous group, Pfam domain, intron-exon organization, transmembrane topology, and secondary/tertiary structural data. Furthermore, to facilitate functional and evolutionary study of these enzymes, a collection of built-in applications for BLAST search, motif identification, sequence and phylogenetic analysis have been seamlessly integrated into the database. dEMBF is the first database that brings together all enzymes responsible for lipid synthesis from available algal genomes, and provides an integrative platform for enzyme inquiry and analysis. This database will be extremely useful for algal biofuel research. It can be accessed at http://bbprof.immt.res.in/embf.

  8. Succession and physiological health of freshwater microalgal fouling in a Tasmanian hydropower canal.

    Science.gov (United States)

    Perkins, Kathryn J; Andrewartha, Jessica M; McMinn, Andrew; Cook, Suellen S; Hallegraeff, Gustaaf M

    2010-08-01

    Freshwater microalgal biofouling in hydropower canals in Tarraleah, Tasmania, is dominated by a single diatom species, Gomphonema tarraleahae. The microfouling community is under investigation with the aim of reducing its impact on electricity generation. Species succession was investigated using removable glass slides. Fouled slides were examined microscopically and for chlorophyll a biomass. Chl a biomass increased steeply after 8 weeks (0.09-0.87 mg m(-2)), but increased much earlier on slides surrounded by a biofouled inoculum. Succession began with low profile diatoms such as Tabellaria flocculosa, progressing to stalked diatoms such as Gomphonema spp. and Cymbella aspera. Few chlorophytes and no filamentous algae were present. Pulse amplitude modulated fluorometry was used to measure the physiological health of fouling on the canal wall. Maximum quantum yield (F(v)/F(m)) measurements were consistently <0.18, indicating that the fouling mat consisted of dead or dying algae. The succession and physiological health of cells in the fouling community has broad implications for mitigation techniques used.

  9. Hydrology Affects Environmental and Spatial Structuring of Microalgal Metacommunities in Tropical Pacific Coast Wetlands.

    Science.gov (United States)

    Rojo, Carmen; Mesquita-Joanes, Francesc; Monrós, Juan S; Armengol, Javier; Sasa, Mahmood; Bonilla, Fabián; Rueda, Ricardo; Benavent-Corai, José; Piculo, Rubén; Segura, M Matilde

    2016-01-01

    The alternating climate between wet and dry periods has important effects on the hydrology and therefore on niche-based processes of water bodies in tropical areas. Additionally, assemblages of microorganism can show spatial patterns, in the form of a distance decay relationship due to their size or life form. We aimed to test spatial and environmental effects, modulated by a seasonal flooding climatic pattern, on the distribution of microalgae in 30 wetlands of a tropical dry forest region: the Pacific coast of Costa Rica and Nicaragua. Three surveys were conducted corresponding to the beginning, the highest peak, and the end of the hydrological year during the wet season, and species abundance and composition of planktonic and benthic microalgae was determined. Variation partitioning analysis (as explained by spatial distance or environmental factors) was applied to each seasonal dataset by means of partial redundancy analysis. Our results show that microalgal assemblages were structured by spatial and environmental factors depending on the hydrological period of the year. At the onset of hydroperiod and during flooding, neutral effects dominated community dynamics, but niche-based local effects resulted in more structured algal communities at the final periods of desiccating water bodies. Results suggest that climate-mediated effects on hydrology can influence the relative role of spatial and environmental factors on metacommunities of microalgae. Such variability needs to be accounted in order to describe accurately community dynamics in tropical coastal wetlands.

  10. Modeling bubble dynamics and radical kinetics in ultrasound induced microalgal cell disruption.

    Science.gov (United States)

    Wang, Meng; Yuan, Wenqiao

    2016-01-01

    Microalgal cell disruption induced by acoustic cavitation was simulated through solving the bubble dynamics in an acoustical field and their radial kinetics (chemical kinetics of radical species) occurring in the bubble during its oscillation, as well as calculating the bubble wall pressure at the collapse point. Modeling results indicated that increasing ultrasonic intensity led to a substantial increase in the number of bubbles formed during acoustic cavitation, however, the pressure generated when the bubbles collapsed decreased. Therefore, cumulative collapse pressure (CCP) of bubbles was used to quantify acoustic disruption of a freshwater alga, Scenedesmus dimorphus, and a marine alga, Nannochloropsis oculata and compare with experimental results. The strong correlations between CCP and the intracellular lipid fluorescence density, chlorophyll-a fluorescence density, and cell particle/debris concentration were found, which suggests that the developed models could accurately predict acoustic cell disruption, and can be utilized in the scale up and optimization of the process. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. The cultivated agricultural environment

    International Nuclear Information System (INIS)

    Eriksson, Aa.

    1997-01-01

    Local agricultural practices in the Nordic countries have resulted in a great diversity in agriculture in the Nordic countries. The diversities mean that in the event of contamination of agricultural land by radioactive fallout the consequences may differ greatly from region to region. For crops and soils contaminated directly by radioactive fallout there are five primary causes for concern, namely: 1. short-term internal contamination of man and animals through ingestion of surface-contaminated mature crops; 2. internal contamination of crops through foliar intake; 3. contamination of mature crops from resuspended soil; 4. direct irradiation of agricultural workers; 5. internal irradiation from inhalation of resuspended soil particulates. In the short-term, most of the radionuclides likely to be released to the atmosphere in the event of an accident have a potential to cause problems in agriculture and many have the potential for causing long-term problems. Generally, the magnitude of the problems created will depend on the: deposition mechanism (wet or dry); radionuclide composition of the fallout; type of farming system (i.e. arable or dairy); type of soil (for instance organic soils are more sensitive than mineral soils with respect to radiocaesium); state of development of the crop which in turn is determined by the season of the year. (EG)

  12. The cultivated agricultural environment

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, Aa [Swedish Univ. of Agricultural Sciences, Dept. of Radioecology (Sweden)

    1997-10-01

    Local agricultural practices in the Nordic countries have resulted in a great diversity in agriculture in the Nordic countries. The diversities mean that in the event of contamination of agricultural land by radioactive fallout the consequences may differ greatly from region to region. For crops and soils contaminated directly by radioactive fallout there are five primary causes for concern, namely: 1. short-term internal contamination of man and animals through ingestion of surface-contaminated mature crops; 2. internal contamination of crops through foliar intake; 3. contamination of mature crops from resuspended soil; 4. direct irradiation of agricultural workers; 5. internal irradiation from inhalation of resuspended soil particulates. In the short-term, most of the radionuclides likely to be released to the atmosphere in the event of an accident have a potential to cause problems in agriculture and many have the potential for causing long-term problems. Generally, the magnitude of the problems created will depend on the: deposition mechanism (wet or dry); radionuclide composition of the fallout; type of farming system (i.e. arable or dairy); type of soil (for instance organic soils are more sensitive than mineral soils with respect to radiocaesium); state of development of the crop which in turn is determined by the season of the year. (EG). 56 refs.

  13. Uranium uptake by hydroponically cultivated crop plants

    Energy Technology Data Exchange (ETDEWEB)

    Soudek, Petr; Petrova, Sarka [Laboratory of Plant Biotechnologies, Joint Laboratory of Institute of Experimental Botany AS CR, v.v.i. and Crop Research Institute, v.v.i., Rozvojova 263, 162 05 Prague 6 (Czech Republic); Benesova, Dagmar [Laboratory of Plant Biotechnologies, Joint Laboratory of Institute of Experimental Botany AS CR, v.v.i. and Crop Research Institute, v.v.i., Rozvojova 263, 162 05 Prague 6 (Czech Republic); Faculty of Environment Technology, Institute of Chemical Technology, Technicka 5, 166 28 Prague 6 (Czech Republic); Dvorakova, Marcela [Laboratory of Plant Biotechnologies, Joint Laboratory of Institute of Experimental Botany AS CR, v.v.i. and Crop Research Institute, v.v.i., Rozvojova 263, 162 05 Prague 6 (Czech Republic); Vanek, Tomas, E-mail: vanek@ueb.cas.cz [Laboratory of Plant Biotechnologies, Joint Laboratory of Institute of Experimental Botany AS CR, v.v.i. and Crop Research Institute, v.v.i., Rozvojova 263, 162 05 Prague 6 (Czech Republic)

    2011-06-15

    Hydroponicaly cultivated plants were grown on medium containing uranium. The appropriate concentrations of uranium for the experiments were selected on the basis of a standard ecotoxicity test. The most sensitive plant species was determined to be Lactuca sativa with an EC{sub 50} value about 0.1 mM. Cucumis sativa represented the most resistant plant to uranium (EC{sub 50} = 0.71 mM). Therefore, we used the uranium in a concentration range from 0.1 to 1 mM. Twenty different plant species were tested in hydroponic solution supplemented by 0.1 mM or 0.5 mM uranium concentration. The uranium accumulation of these plants varied from 0.16 mg/g DW to 0.011 mg/g DW. The highest uranium uptake was determined for Zea mays and the lowest for Arabidopsis thaliana. The amount of accumulated uranium was strongly influenced by uranium concentration in the cultivation medium. Autoradiography showed that uranium is mainly localized in the root system of the plants tested. Additional experiments demonstrated the possibility of influencing the uranium uptake from the cultivation medium by amendments. Tartaric acid was able to increase uranium uptake by Brassica oleracea and Sinapis alba up to 2.8 times or 1.9 times, respectively. Phosphate deficiency increased uranium uptake up to 4.5 times or 3.9 times, respectively, by Brassica oleracea and S. alba. In the case of deficiency of iron or presence of cadmium ions we did not find any increase in uranium accumulation. - Highlights: > The uranium accumulation in twenty different plant species varied from 0.160 to 0.011 mg/g DW. > Uranium is mainly localized in the root system. > Tartaric acid was able to increase uranium uptake by Brassica oleracea and Sinapis alba. > The phosphates deficiency increase the uranium uptake.

  14. Uranium uptake by hydroponically cultivated crop plants

    International Nuclear Information System (INIS)

    Soudek, Petr; Petrova, Sarka; Benesova, Dagmar; Dvorakova, Marcela; Vanek, Tomas

    2011-01-01

    Hydroponicaly cultivated plants were grown on medium containing uranium. The appropriate concentrations of uranium for the experiments were selected on the basis of a standard ecotoxicity test. The most sensitive plant species was determined to be Lactuca sativa with an EC 50 value about 0.1 mM. Cucumis sativa represented the most resistant plant to uranium (EC 50 = 0.71 mM). Therefore, we used the uranium in a concentration range from 0.1 to 1 mM. Twenty different plant species were tested in hydroponic solution supplemented by 0.1 mM or 0.5 mM uranium concentration. The uranium accumulation of these plants varied from 0.16 mg/g DW to 0.011 mg/g DW. The highest uranium uptake was determined for Zea mays and the lowest for Arabidopsis thaliana. The amount of accumulated uranium was strongly influenced by uranium concentration in the cultivation medium. Autoradiography showed that uranium is mainly localized in the root system of the plants tested. Additional experiments demonstrated the possibility of influencing the uranium uptake from the cultivation medium by amendments. Tartaric acid was able to increase uranium uptake by Brassica oleracea and Sinapis alba up to 2.8 times or 1.9 times, respectively. Phosphate deficiency increased uranium uptake up to 4.5 times or 3.9 times, respectively, by Brassica oleracea and S. alba. In the case of deficiency of iron or presence of cadmium ions we did not find any increase in uranium accumulation. - Highlights: → The uranium accumulation in twenty different plant species varied from 0.160 to 0.011 mg/g DW. → Uranium is mainly localized in the root system. → Tartaric acid was able to increase uranium uptake by Brassica oleracea and Sinapis alba. → The phosphates deficiency increase the uranium uptake.

  15. Effects of different cultivation techniques on vineyard fauna

    OpenAIRE

    Mikulas, J.; Kutasi, Cs.; Mark, V.; Balog, A.

    2002-01-01

    Green covering compared to soil cultivation enhanced the number of individuals of Araneae living on or near soil. No differences between the different soil management systems were found for the number of individuals of Staphylinidae and Carabidae. The typical main species of the two systems were different for all groups analyzed (Araneae, Staphylinidae and Carabidae).

  16. Production of deuterated switchgrass by hydroponic cultivation.

    Science.gov (United States)

    Evans, Barbara R; Bali, Garima; Foston, Marcus; Ragauskas, Arthur J; O'Neill, Hugh M; Shah, Riddhi; McGaughey, Joseph; Reeves, David; Rempe, Caroline S; Davison, Brian H

    2015-07-01

    The bioenergy crop switchgrass was grown hydroponically from tiller cuttings in 50 % D 2 O to obtain biomass with 34 % deuterium substitution and physicochemical properties similar to those of H 2 O-grown switchgrass controls. Deuterium enrichment of biological materials can potentially enable expanded experimental use of small angle neutron scattering (SANS) to investigate molecular structural transitions of complex systems such as plant cell walls. Two key advances have been made that facilitate cultivation of switchgrass, an important forage and biofuel crop, for controlled isotopic enrichment: (1) perfusion system with individual chambers and (2) hydroponic growth from tiller cuttings. Plants were grown and maintained for several months with periodic harvest. Photosynthetic activity was monitored by measurement of CO2 in outflow from the growth chambers. Plant morphology and composition appeared normal compared to matched controls grown with H2O. Using this improved method, gram quantities of switchgrass leaves and stems were produced by continuous hydroponic cultivation using growth medium consisting of basal mineral salts in 50 % D2O. Deuterium incorporation was confirmed by detection of the O-D and C-D stretching peaks with FTIR and quantified by (1)H- and (2)H-NMR. This capability to produce deuterated lignocellulosic biomass under controlled conditions will enhance investigation of cell wall structure and its deconstruction by neutron scattering and NMR techniques.

  17. Biofuel and Biochemical Analysis of Amphora coffeaeformis RR03, a Novel Marine Diatom, Cultivated in an Open Raceway Pond

    Directory of Open Access Journals (Sweden)

    Muthu Ganesan Rajaram

    2018-05-01

    Full Text Available (1 Background: To increase the biochemical productivity and to reduce the production cost of microalgal biodiesel, this study aimed to investigate the effects of CO2 on biomass, fatty acids, carbon-hydrogen, and biochemical accumulation of the marine diatom, Amphora coffeaeformis RR03 (A. coffeaeformis RR03. (2 Methods: Fatty acid composition of the dry biomass of A. coffeaeformis RR03 was analysed using Gas chromatography-mass spectrometry (GC-MS. (3 Results: The results showed that A. coffeaeformis RR03 contained high biomass productivity and biochemical composition in different cultivation conditions. A. coffeaeformis RR03 showed maximum growth of 5.2 × 106/mL on 21st day cultivation under CO2 supply. The bio-crude oil production from A. coffeaeformis RR03 was 36.19 megajoule (MJ. GC-MS analysis found that the dry biomass of A. coffeaeformis RR03 contained maximum of 47.72% fatty acids of 16-octadecanoic acid methyl ester (10:12 and 19.58% pentadecanoic acid, 13-methyl-, and methyl ester (9.24. (4 Conclusion: The results of this study may suggest that a novel diatom of A. coffeaeformis RR03 could be a suitable candidate for biocrude production in order to meet the future demand of energy.

  18. Re-envisioning the renewable fuel standard to minimize unintended consequences: A comparison of microalgal diesel with other biodiesels

    International Nuclear Information System (INIS)

    Soratana, Kullapa; Khanna, Vikas; Landis, Amy E.

    2013-01-01

    Highlights: • Conducted a life cycle assessment (LCA) of microalgal diesel from PBR to combustion. • Compared the results with other existing LCA results of petroleum and other biodiesels. • Assessed the current Renewable Fuel Standard (RFS2). • Proposed an approach to set emission thresholds for eutrophication (EP) and smog formation potentials (PSP). • Future RFS should include a life-cycle emissions threshold for EP and PSP. - Abstract: The Renewable Fuel Standard 2 (RFS2) program under the Energy Independence and Security Act of 2007 set a life-cycle emission reduction threshold to only greenhouse gas (GHG) emissions; this type of single-dimensional threshold could lead to the unintended trading of one environmental problem for another. Many of the environmental impacts resulting over the life cycle of oil-crop biodiesel fuels manifest in the agricultural phase of production in the form of water quality degradation. This study investigated the extent to which different biofuels meet the RFS GHG requirement, and presents alternative strategies for minimizing unintended consequences. In addition to life-cycle global warming potential (GWP), the eutrophication potential (EP) and photochemical smog formation potential (PSP) from microalgal diesel were compared to the impacts resulting from petroleum-based diesel, soybean diesel and canola diesel. The results showed tradeoffs between GWP and eutrophication potential when microalgal diesel was compared to soybean diesel. Future RFS criteria should include EP and PSP metrics, however establishing thresholds like the GHG management approach may not be appropriate for these other impacts. Two possible strategies to setting life-cycle eutrophication standards are to establish a threshold based on first generation biofuels, as opposed to petro-fuels or to set maximum levels of EP loads for major watersheds or coastal areas. To decrease PSP, together with existing standards for tailpipe emissions, future RFSs

  19. Indicadores de qualidade do solo em sistemas de cultivo orgânico e convencional no semi-árido cearense Soil quality indicators in organic and conventional cultivation systems in the semi arid areas of Ceara - Brazil

    Directory of Open Access Journals (Sweden)

    Herdjania Veras de Lima

    2007-10-01

    Full Text Available A qualidade do solo pode mudar com o passar do tempo, em decorrência de eventos naturais ou ações antrópicas. A adoção de práticas de cultivo orgânico reduz o revolvimento do solo, favorecendo a recuperação de suas propriedades físicas e químicas. Este trabalho teve como objetivo comparar propriedades físicas, químicas e biológicas de solos cultivados com algodão em bases orgânicas e no sistema convencional, assim como identificar as que possam ser utilizadas como indicadores de qualidade do solo. Selecionaram-se seis áreas submetidas ao cultivo orgânico e três ao cultivo convencional para coleta de amostras de solo deformadas e indeformadas, nas camadas de 0-10, 10-20 e 20-30 cm. Técnicas de estatística univariada e multivariada foram utilizadas para análise dos dados. Os resultados mostraram que os indicadores físicos e químicos testados individualmente não foram sensíveis para diferenciar as áreas sob sistema de cultivo orgânico daquelas sob cultivo convencional. No entanto, a aplicação de técnicas de análise multivariada - no caso, componentes principais e a discriminante de Anderson - permitiu a distinção entre algumas áreas cultivadas sob cultivo orgânico comparativamente às convencionais, até mesmo as que estavam em transição. Dos indicadores biológicos, a fauna edáfica mostrou-se mais precisa na avaliação da qualidade do solo, distinguindo de forma satisfatória as áreas sob sistema de cultivo orgânico das que estavam sob sistema convencional.Soil quality can change along the time due to natural events or anthropic activities. The use of organic management practices reduces soil tillage and favors the recovery of soil physical and chemical properties. The objective of this study was to compare the physical, chemical and biological properties of cultivated soils under organic system or conventional tillage system. Six organic and three conventional cultivated areas were selected and soil

  20. Exogenous Gene Integration for Microalgal Cell Transformation Using a Nanowire-Incorporated Microdevice.

    Science.gov (United States)

    Bae, Sunwoong; Park, Seunghye; Kim, Jung; Choi, Jong Seob; Kim, Kyung Hoon; Kwon, Donguk; Jin, EonSeon; Park, Inkyu; Kim, Do Hyun; Seo, Tae Seok

    2015-12-16

    Superior green algal cells showing high lipid production and rapid growth rate are considered as an alternative for the next generation green energy resources. To achieve the biomass based energy generation, transformed microalgae with superlative properties should be developed through genetic engineering. Contrary to the normal cells, microalgae have rigid cell walls, so that target gene delivery into cells is challengeable. In this study, we report a ZnO nanowire-incorporated microdevice for a high throughput microalgal transformation. The proposed microdevice was equipped with not only a ZnO nanowire in the microchannel for gene delivery into cells but also a pneumatic polydimethylsiloxane (PDMS) microvalve to modulate the cellular attachment and detachment from the nanowire. As a model, hygromycin B resistance gene cassette (Hyg3) was functionalized on the hydrothermally grown ZnO nanowires through a disulfide bond and released into green algal cells, Chlamydomonas reinhardtii, by reductive cleavage. During Hyg3 gene delivery, a monolithic PDMS membrane was bent down, so that algal cells were pushed down toward ZnO nanowires. The supply of vacuum in the pneumatic line made the PDMS membrane bend up, enabling the gene delivered algal cells to be recovered from the outlet of the microchannel. We successfully confirmed Hyg3 gene integrated in microalgae by amplifying the inserted gene through polymerase chain reaction (PCR) and DNA sequencing. The efficiency of the gene delivery to algal cells using the ZnO nanowire-incorporated microdevice was 6.52 × 10(4)- and 9.66 × 10(4)-fold higher than that of a traditional glass bead beating and electroporation.

  1. Modelling growth of, and removal of Zn and Hg by a wild microalgal consortium

    Energy Technology Data Exchange (ETDEWEB)

    Monteiro, Cristina M.; Brandao, Teresa R.S.; Castro, Paula M.L. [Universidade Catolica Portuguesa, Porto (Portugal). CBQF/Escola Superior de Biotecnologia; Malcata, F. Xavier [ISMAI - Instituto Superior da Maia, Avioso S. Pedro (Portugal); CIMAR/CIIMAR - Centro Interdisciplinar de Investigacao Marinha e Ambiental, Porto (Portugal)

    2012-04-15

    Microorganisms isolated from sites contaminated with heavy metals usually possess a higher removal capacity than strains from regular cultures. Heavy metal-containing soil samples from an industrial dumpsite in Northern Portugal were accordingly collected; following enrichment under metal stress, a consortium of wild microalgae was obtained. Their ability to grow in the presence of, and their capacity to recover heavy metals was comprehensively studied; the datasets thus generated were fitted to by a combined model of biomass growth and metal uptake, derived from first principles. After exposure to 15 and 25 mg/L Zn{sup 2+} for 6 days, the microalgal consortium reached similar, or higher cell density than the control; however, under 50 and 65 mg/L Zn{sup 2+}, 71% to 84% inhibition was observed. Growth in the presence of Hg{sup 2+} was significantly inhibited, even at a concentration as low as 25 {mu}g/L, and 90% inhibition was observed above 100 {mu}g/L. The maximum amount of Zn{sup 2+} removed was 21.3 mg/L, upon exposure to 25 mg/L for 6 day, whereas the maximum removal of Hg{sup 2+} was 335 {mu}g/L, upon 6 day in the presence of 350 {mu}g/L. The aforementioned mechanistic model was built upon Monod assumptions (including heavy metal inhibition), coupled with Leudeking-Piret relationships between the rates of biomass growth and metal removal. The overall fits were good under all experimental conditions tested, thus conveying a useful tool for rational optimisation of microalga-mediated bioremediation. (orig.)

  2. Dual uses of microalgal biomass: An integrative approach for biohydrogen and biodiesel production

    International Nuclear Information System (INIS)

    Dasgupta, Chitralekha Nag; Suseela, M.R.; Mandotra, S.K.; Kumar, Pankaj; Pandey, Manish K.; Toppo, Kiran; Lone, J.A.

    2015-01-01

    Highlights: • Chlorella sp. NBRI029 and Scenedesmus sp. NBRI012 shows high biomass productivity. • Scenedesmus sp. NBRI012 shows maximum H 2 evolution in 6th day of fermentation. • Residual biomass after H 2 production contains high lipid content. • Lipid extracted from the residual biomass fulfills various biodiesel properties. - Abstract: Dual application of biomass for biohydrogen and biodiesel production could be considered a feasible option for economic and sustainable energy production from microalgae. In this study, after a large screening of fresh water microalgal isolates, Scenedesmus sp. NBRI012 and Chlorella sp. NBRI029 have exhibited high biomass (1.31 ± 0.11 and 2.62 ± 0.13 g/L respectively) and lipid (244.44 ± 12.3 and 587.38 ± 20.2 mg/L respectively) yield with an organic carbon (acetate) source. Scenedesmus sp. NBRI012 has shown the highest H 2 (maximum evolution of 17.72% v/v H 2 of total gases) production; it produced H 2 continuously for seven days in sulfur-deprived TAP media. Sulfur deprivation during the H 2 production was found to increase the lipid content (410.03 ± 18.5 mg/L) of the residual biomass. Fatty acid profile of the lipid extracted from the residual biomass of Scenedesmus sp. NBRI012 has showed abundance of fatty acids with a carbon chain length of C16 and C18. Cetane number, iodine value, and saponification value of biodiesel were found suitable according to the range given by the Indian standard (IS 15607), Brazilian National Petroleum Agency (ANP255) and the European biodiesel standard EN14214

  3. Photobioreactor cultivation strategies for microalgae and cyanobacteria.

    Science.gov (United States)

    Johnson, Tylor J; Katuwal, Sarmila; Anderson, Gary A; Gu, Liping; Zhou, Ruanbao; Gibbons, William R

    2018-03-08

    The current burden on fossil-derived chemicals and fuels combined with the rapidly increasing global population has led to a crucial need to develop renewable and sustainable sources of chemicals and biofuels. Photoautotrophic microorganisms, including cyanobacteria and microalgae, have garnered a great deal of attention for their capability to produce these chemicals from carbon dioxide, mineralized water, and solar energy. While there have been substantial amounts of research directed at scaling-up production from these microorganisms, several factors have proven difficult to overcome, including high costs associated with cultivation, photobioreactor construction, and artificial lighting. Decreasing these costs will substantially increase the economic feasibility of these production processes. Thus, the purpose of this review is to describe various photobioreactor designs, and then provide an overview on lighting systems, mixing, gas transfer, and the hydrodynamics of bubbles. These factors must be considered when the goal of a production process is economic feasibility. Targets for improving microalgae and cyanobacteria cultivation media, including water reduction strategies will also be described. As fossil fuel reserves continue to be depleted and the world population continues to increase, it is imperative that renewable chemical and biofuel production processes be developed toward becoming economically feasible. Thus, it is essential that future research is directed toward improving these processes. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 2018. © 2018 American Institute of Chemical Engineers.

  4. Site-specific cultivation systems for energy plants. Results of the joint project ''Development and comparison of optimized cultivation systems for the agricultural production of energy plants at different site-specific conditions in the Federal Republic of Germany, EVA I''. 3. rev. and enl. ed.; Standortangepasste Anbausysteme fuer Energiepflanzen. Ergebnisse des Verbundprojektes ''Entwicklung und Vergleich von optimierten Anbausystemen fuer die landwirtschaftliche Produktion von Energiepflanzen unter den verschiedenen Standortbedingungen Deutschlands, EVA I''

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-03-15

    With respect to the estimations of the Agency for Renewable Ressources (Guelzow, Federal Republic of Germany), nearly 2 millions ha of the area of arable land in Germany were used for the production of renewable raw materials in the last years. The production of vegetable energy sources only was limited on few cultural species. This led to criticism by organisations of nature protection and environmental protection. The joint project 'Development and comparison of optimized cultivation system for the agricultural production of energy plants at different site specific conditions in the Federal Republic of Germany' was one of the most extensive national agrarian research projects of the past years. This joint project offers practice-relevant knowledge to efficient and sustainable cultivation systems of energy plants. The brochure under consideration reports on the results of the first project phase of this joint project.

  5. Produção hidropônica de morangueiro em sistema de colunas verticais, sob cultivo protegido Hydroponic strawberry production in vertical columns system under protected cultivation

    Directory of Open Access Journals (Sweden)

    Eunice Oliveira Calvete

    2007-01-01

    Full Text Available O cultivo do morangueiro fora do solo possibilita a eliminação do uso de produtos para desinfecção, reduzindo o consumo de frutos contaminados e a agressão ao meio ambiente, além de proporcionar melhor aproveitamento da área e maior facilidade de manejo da cultura. Este trabalho teve como objetivo avaliar, em ambiente protegido e colunas verticais, dois sistemas de irrigação: gotejamento por estacas (externo e autocompensante (interno; dois tipos de substratos: Horta 2 e Tabaco 1; com e sem drenagem. A cultivar utilizada foi a Oso Grande. O delineamento foi em blocos casualizados, com os tratamentos dispostos em parcela subsubdividida, com três repetições. Com base nos rendimentos obtidos nos terços superior, médio e inferior das colunas, o sistema de irrigação mais indicado é o gotejamento por estacas (externo, com drenagem na extremidade inferior da coluna. Os substratos não diferem quanto à produção, mas Horta 2 incrementa o teor de antocianina nos frutos.Since strawberry cultivation in soil less system does not needs disinfection products, it decreases fruits and environmental contamination. Besides it provides a better utilization of the area and makes easy the management of the culture. The objective of this work was to evaluate two irrigation systems: dripping for props (outside and self compensate (inside; and two types of substrates: Horta 2 and Tabaco 1; with or without draining, on the cultivar Oso Grande of strawberry. The experiment was carried out under protected cultivation and in vertical columns conditions. The experimental design was randomized blocks, with three replications, and the treatments were arranged in a split-plot. The strawberry yield found in the upper, medium, and lower positions of the columns indicates that the dripping for props (outside is the most efficient irrigation system, since drainage is used in the lower extremity of the column. Although there were no differences substrates, Horta

  6. Plants cultivation in controlled containments

    International Nuclear Information System (INIS)

    2000-01-01

    The plants cultivation in controlled containments permits to the - Departement d'Ecophysiologie Vegetale et de Microbiologie (DVEM) - of the CEA to lead several topics of research. The works of DVEM which are based on the molecular labelling, technique adapted to plants, contribute to understand the plant - soil relationships and the plant growth process. In addition, the staff of DVEM study the impact of pollutant heavy metals, existing in the soil, on plants and the plant stress induced by oxygen, light, ionizing radiations,... and defence mechanisms of plants (F. M.)

  7. Graphical coding data and operational guidance for implementation or modification of a LabVIEW®-based pHstat system for the cultivation of microalgae.

    Science.gov (United States)

    Golda, Rachel L; Golda, Mark D; Peterson, Tawnya D; Needoba, Joseph A

    2017-06-01

    The influence of pH on phytoplankton physiology is an important facet of the body of research on ocean acidification. We provide data developed during the design and implementation of a novel pHstat system capable of maintaining both static and dynamic pH environments in a laboratory setting. These data both help improve functionality of the system, and provide specific coding blocks for controlling the pHstat using a LabVIEW® virtual instrument (VI). The data in this paper support the research article "Development of an economical, autonomous pHstat system for culturing phytoplankton under steady state or dynamic conditions" (Golda et al. [2]). These data will be of interest to researchers studying the effects of changing pH on phytoplankton in a laboratory context, and to those desiring to build their own pHstat system(s). These data can also be used to facilitate modification of the pHstat system to control salinity, temperature, or other environmental factors.

  8. Aggregate Stability of Tropical Soils Under Long-Term Eucalyptus Cultivation

    Science.gov (United States)

    Eucalyptus cultivation has increased in all Brazilian regions. Despite the large amount of cultivated area, little is known about how this kind of management system affects soil properties, mainly the aggregate stability. Aggregate stability analyses have proved to be a sensitive tool to measure soi...

  9. Sequencing of a Cultivated Diploid Cotton Genome-Gossypium arboreum

    Institute of Scientific and Technical Information of China (English)

    WILKINS; Thea; A

    2008-01-01

    Sequencing the genomes of crop species and model systems contributes significantly to our understanding of the organization,structure and function of plant genomes.In a `white paper' published in 2007,the cotton community set forth a strategic plan for sequencing the AD genome of cultivated upland cotton that initially targets less complex diploid genomes.This strategy banks on the high degree

  10. Simultaneous improvement in production of microalgal biodiesel and high-value alpha-linolenic acid by a single regulator acetylcholine.

    Science.gov (United States)

    Parsaeimehr, Ali; Sun, Zhilan; Dou, Xiao; Chen, Yi-Feng

    2015-01-01

    Photoautotrophic microalgae are a promising avenue for sustained biodiesel production, but are compromised by low yields of biomass and lipids at present. We are developing a chemical approach to improve microalgal accumulation of feedstock lipids as well as high-value alpha-linolenic acid which in turn might provide a driving force for biodiesel production. We demonstrate the effectiveness of the small bioactive molecule "acetylcholine" on accumulation of biomass, total lipids, and alpha-linolenic acid in Chlorella sorokiniana. The effectiveness exists in different species of Chlorella. Moreover, the precursor and analogs of acetylcholine display increased effectiveness at higher applied doses, with maximal increases by 126, 80, and 60% over controls for biomass, total lipids, and alpha-linolenic acid, respectively. Production of calculated biodiesel was also improved by the precursor and analogs of acetylcholine. The biodiesel quality affected by changes in microalgal fatty acid composition was addressed. The chemical approach described here could improve the lipid yield and biodiesel production of photoautotrophic microalgae if combined with current genetic approaches.

  11. Molecular characterization of two microalgal strains in Egypt and investigation of the antimicrobial activity of their extracts

    Directory of Open Access Journals (Sweden)

    El Semary, NA.

    2013-01-01

    Full Text Available The emergence of new pathogens and the increasing drug-resistance of recognized ones pose a difficult challenge. One way that this challenge is being addressed is through the discovery of new cost-effective drug resources in the form of bioactive compounds. Algae represent a promising source of bioactive compounds in this regard. In the present research, we used molecular and phylogenetic analysis to isolate and identify two microalgal strains. We found that one strain belonged to the phylum chrysophyta and the other to the cyanobacteria. We also investigated the antimicrobial activity of some of the lipophilic extracts of the two microalgal strains. Several fractions showed high individual antimicrobial bioactivity against multidrug-resistant Salmonella sp., Citrobacter sp., Aspergillus niger and Aspergillus flavus. Fraction III from Poterioochromonas malhamensis showed the highest level of activity against two multidrug-resistant bacterial pathogens. The inhibition zone diameter was 1.4 cm for Salmonella and 1.4 cm for Citrobacter. Meanwhile, another lipophilic fraction from the cyanobacterium Synechocystis salina showed broad-spectrum bioactivity (inhibition zone diameter of 0.9 cm for Aspergillus niger, 1 cm for Citrobacter and 0.9 cm for Salmonella. One lipophilic fraction from Aphanizomenon showed antifungal bioactivity against Aspergillus niger and Aspergillus flavus, where the inhibition zone diameter was 1.1 cm and 1.0 cm, respectively. The study highlights the antimicrobial bioactivity of extracts from local microalgae and emphasizes the importance of carrying out screening programs for those microorganisms.

  12. Significance, progress and prospects for research in simplified cultivation technologies for rice in China.

    Science.gov (United States)

    Huang, M; Ibrahim, Md; Xia, B; Zou, Y

    2011-08-01

    Simplified cultivation technologies for rice have become increasingly attractive in recent years in China because of their social, economical and environmental benefits. To date, several simplified cultivation technologies, such as conventional tillage and seedling throwing (CTST), conventional tillage and direct seeding (CTDS), no-tillage and seedling throwing (NTST), no-tillage and direct seeding (NTDS) and no-tillage and transplanting (NTTP), have been developed in China. Most studies have shown that rice grown under each of these simplified cultivation technologies can produce a grain yield equal to or higher than traditional cultivation (conventional tillage and transplanting). Studies that have described the influences of agronomic practices on yield formation of rice under simplified cultivation have demonstrated that optimizing agronomy practices would increase the efficiencies of simplified cultivation systems. Further research is needed to optimize the management strategies for CTST, CTDS and NTST rice which have developed quickly in recent years, to strengthen basic research for those simplified cultivation technologies that are rarely used at present (such as NTTP and NTDS), to select and breed cultivars suitable for simplified cultivation and to compare the practicability and effectiveness of different simplified cultivation technologies in different rice production regions.

  13. Feasibility Study on Sterilization of Badge using Radiation and Cultivation by Nano-bubble Water for Matsutake Mushroom Cultivation

    International Nuclear Information System (INIS)

    Jung, Inha

    2013-12-01

    This report on the 'Sterilization of Badge using Radiation and Cultivation by Nano-bubble Water for Matsutake Mushroom Cultivation' is belonged to the final report on the preliminary study of the first subject in 2013 for civilian project. This was complimented on the responsible of the Korea Atomic Energy Research Institute for 1 st of June 2013 to 30 th of November 2013. We are going to make sterilization the badge using the gamma ray and supplying the oxygen by nano-bubble oxygen rich water for cultivating the Matsutake Mushroom, instead of the conventional process of sterilization of the badge by hot steam over 120 .deg. C consuming over 8 hours and expensive ventilation system for supplying the fresh air for delivering the oxygen

  14. Feasibility Study on Sterilization of Badge using Radiation and Cultivation by Nano-bubble Water for Matsutake Mushroom Cultivation

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Inha

    2013-12-15

    This report on the 'Sterilization of Badge using Radiation and Cultivation by Nano-bubble Water for Matsutake Mushroom Cultivation' is belonged to the final report on the preliminary study of the first subject in 2013 for civilian project. This was complimented on the responsible of the Korea Atomic Energy Research Institute for 1{sup st} of June 2013 to 30{sup th} of November 2013. We are going to make sterilization the badge using the gamma ray and supplying the oxygen by nano-bubble oxygen rich water for cultivating the Matsutake Mushroom, instead of the conventional process of sterilization of the badge by hot steam over 120 .deg. C consuming over 8 hours and expensive ventilation system for supplying the fresh air for delivering the oxygen.

  15. Harvesting microalgae using activated sludge can decrease polymer dosing and enhance methane production via co-digestion in a bacterial-microalgal process

    DEFF Research Database (Denmark)

    Wágner, Dorottya Sarolta; Radovici, Maria; Smets, Barth F.

    2016-01-01

    , there is the potential to produce energy by co-digesting the two types of biomass. We present an innovative approach to recover microalgal biomass via a two-step flocculation using bacterial biomass after the destabilisation of microalgae with conventional cationic polymer. A short solids retention time (SRT) enhanced...

  16. The use of 32P Method to Evaluate the Growth of Lowland Rice Cultivated in a System of Rice Intensification (SRI

    Directory of Open Access Journals (Sweden)

    A. Citraresmini

    2013-08-01

    Full Text Available A pot experiment has been conducted to evaluate the growth of the Dyah Suci, a lowland rice variety, in an SRI (System of Rice Intensification planting system. The phosphorus-32 (32P isotope technique was used to evaluate the growth of plants in relation with their phosphorus uptake. The uptake was assumed to vary in the same direction as the growth of the plant. The 32P uptake is assumed to vary in the opposite direction to the plant’s total phosphorus uptake. Here the 32P uptake is expressed in count per minutes (cpm which is then transformed to disintegration per minute (dpm. The results show that, in terms of promoting the plant’s uptake of phosphorus, the SRI planting system is superior to the conventional planting system, and it is manifested in the higher dry weight of straw and grain. From this experiment it is concluded that the 32P method can be used satisfactorily as a tool for explaining the relation between P-uptake and plant growth

  17. Climate-Adapted Soil Cultivation as an Aspect for Sustainable Farming – Task-Technology-Fit of a Decision Support System

    Directory of Open Access Journals (Sweden)

    Welf Guenther-Lübbers

    2013-03-01

    Full Text Available Due to global climate change and its impact on local weather conditions, decision support systems are becoming more important in agriculture. Such systems allow farmers to adapt more effectively to the complex changes affecting their farms. Marginal production sites must apply new tillage strategies adapted to new climatic conditions. Information about proper strategy adjustments is often disseminated through agricultural extension services and journals. A new internet information platform, KlimaBob, which focuses on climate-flexible tillage, was established under the auspices of the Innovation Network of Climate Change Adaptation Brandenburg Berlin. Successful and permanent introduction of such a system requires analysis and verification of its acceptance among individual farmers. This study addresses this need by applying the established task-technology fit approach. A survey was conducted among farmers in the Brandenburg region. The resulting data provided the basis for a structural equation model that explains and evaluates the task-technology fit of the KlimaBob platform. The results indicate that the performance spectrum of the system exerts a strong influence on the task-technology fit when assessed by both the name characteristics of KlimaBob and the individual characteristics of users (for example, time management, technology affinity and risk attitude.

  18. Efficiency of a novel "Food to waste to food" system including anaerobic digestion of food waste and cultivation of vegetables on digestate in a bubble-insulated greenhouse.

    Science.gov (United States)

    Stoknes, K; Scholwin, F; Krzesiński, W; Wojciechowska, E; Jasińska, A

    2016-10-01

    At urban locations certain challenges are concentrated: organic waste production, the need for waste treatment, energy demand, food demand, the need for circular economy and limited area for food production. Based on these factors the project presented here developed a novel technological approach for processing organic waste into new food. In this system, organic waste is converted into biogas and digester residue. The digester residue is being used successfully as a stand-alone fertilizer as well as main substrate component for vegetables and mushrooms for the first time - a "digeponics" system - in a closed new low energy greenhouse system with dynamic soap bubble insulation. Biogas production provides energy for the process and CO2 for the greenhouse. With very limited land use highly efficient resource recycling was established at pilot scale. In the research project it was proven that a low energy dynamic bubble insulated greenhouse can be operated continuously with 80% energy demand reduction compared to conventional greenhouses. Commercial crop yields were achieved based on fertilization with digestate; in individual cases they were even higher than the control yields of vegetables such as tomatoes, cucumber and lettuce among others. For the first time an efficient direct use of digestate as substrate and fertilizer has been developed and demonstrated. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Two-phase systems: Potential for in situ extraction of microalgal products

    NARCIS (Netherlands)

    Kleinegris, D.M.M.; Janssen, M.G.J.; Brandenburg, W.A.; Wijffels, R.H.

    2011-01-01

    Algae are currently used for production of niche products and are becoming increasingly interesting for the production of bulk commodities, such as biodiesel. For the production of these goods to become economically feasible, production costs will have to be lowered by one order of magnitude. The

  20. Development of labor saving operation technique by making large scale paddy field and direct seeding cultivation of rice in Tohoku district [Japan], 2: Development of technique for automatic precision laser-levelling system

    International Nuclear Information System (INIS)

    Kimura, S.; Imazono, S.; Yaji, Y.

    1999-01-01

    1) Preparation for large large paddy fields and utilization of direct rice seeding cultivation are expected to be the key technologies for the low cost and labor saving large farm rice cultivation. To achieve this, the technique of land leveling for field operations have to be developed. A precise land leveling operation by a wheel tractor with laser-beam emitter and recover in a wet paddy field are developed. 2) The automatic measurement system of a rice paddy field surface level by a tractor that we developed was highly practical. After measured data ate stored in a memory of hand-held computer the standard deviation of a field height value is shown on the display. Also, measured data are exported to the personal computer and by RC232C, the contour map of the paddy field is draw quickly, which is useful for the land leveling work. 3) Considering the relation between rice seed germination and water depth in the field, the preciseness of the field leveling for direct rice seeding is required to be under 1.5cm of standard deviation (s.d.). To realize this preciseness, a prototype leveling aparatus consisting a laser emitter, a laser receiver and dry land leveler pulled by a tracter, was developed and was tested the performance. The results of land leveling test at a field of 1 ha indicated that the elevation difference of the field of 16cm was improved to that of 92% of +- 2.5cm (1.58cm s.d.) after leveling work. The working efficiency was 0.57hour/10a. For a precise leveling work, the of the soil water content should be under the plastic limitation, under which less amount of soil adoheres to the blade of the leveler. The performance tests of the laser assisted leveling apparatus for a paddy harrowing work revealed that for an accurate operation only a blade should be controlled by a hydraulic cylinder according to a laser beam. Since large amount of soil can not be handled by the apparatus, the leveling for a paddy harrowing work is recommended for a fine leveling

  1. Lipid extracted microalgal biomass residue as a fertilizer substitute for Zea mays L

    Directory of Open Access Journals (Sweden)

    Rahulkumar eMaurya

    2016-01-01

    Full Text Available High volumes of lipid extracted microalgal biomass residues (LMBRs are expected to be produced upon commencement of biodiesel production on a large scale, thus necessitating its value addition for sustainable development. LMBRs of Chlorella variabilis and Lyngbya majuscula were employed to substitute the nitrogen content of recommended rate of fertilizer (RRF for Zea mays L. The pot experiment comprised of 10 treatments, i.e. T1 (No fertilizer; T2 (RRF-120 N: 60 P2O5: 40 K2O kg ha-1; T3 to T6 -100, 75, 50 and 25% N through LMBR of the Chlorella sp., respectively; T7 to T10 -100, 75, 50 and 25% N through LMBR of Lyngbya sp., respectively. It was found that all LMBR substitution treatments were at par to RRF with respect to grain yield production. T10 gave the highest grain yield (65.16 g plant-1, which was closely followed by that (63.48 g plant-1 under T5. T10 also recorded the highest phosphorus and potassium contents in grains. T4 was markedly superior over control in terms of dry matter accumulation (DMA as well as carbohydrate content, which was ascribed to higher pigment content and photosynthetic activity in leaves. Even though considerably lower DMA was obtained in Lyngbya treatments, which might have been due to the presence of some toxic factors, no reduction in grain yield was apparent. The length of the tassel was significantly higher in either of the LMBRs at any substitution rates over RRF, except T6 and T7. The ascorbate peroxidase activity decreased with decreasing dose of Chlorella LMBR, while all the Lyngbya LMBR treatments recorded lower activity, which were at par with each other. Among the Chlorella treatments, only T5 recorded significantly higher values of glutathione reductase activity over RRF, while the rest were at par. There were significant increases in carbohydrate and crude fat, respectively, only in T4 and T3 over RRF, while no change was observed in crude protein due to LMBR treatments. Apparently, there was no

  2. Qualidade de frutos de laranjeira Valência cultivada sob sistema tecnificado Quality of Valencia orange fruits cultivated under technified system

    Directory of Open Access Journals (Sweden)

    Regina K. Grizotto

    2012-07-01

    Full Text Available Estudou-se, neste estudo, o efeito de um pacote tecnológico implementado no pomar laranjeira Valência em comparação com o sistema convencional tendo-se por base a produção e a qualidade dos frutos colhidos. As tecnologias praticadas constam de adensamento, adubação na implantação e formação, tratamento fitossanitário, manejo de plantas invasoras, irrigação e poda de formação. Os resultados obtidos dos frutos da primeira colheita mostraram que o sistema tecnificado com irrigação (ST + I promoveu aumento significativo no rendimento de colheita, o qual foi maior em pomares com maior adensamento de 727 plantas ha-1 (espaçamento 5,5 x 2,5 m ou 667 plantas ha-1 (espaçamento 6,0 x 2,5 m. A irrigação em sistema tecnificado resultou em frutos com maior tamanho e, consequentemente, menor número de frutos para compor uma caixa padrão, menores teores de sólidos solúveis e acidez titulável. Não houve variação no rendimento em suco, independente do sistema de produção ou espaçamento utilizado. Conclui-se que, nesta primeira avaliação, a implementação de sistema tecnificado de manejo de pomar concomitante à irrigação (ST + I é interessante, uma vez que promove maior rendimento de colheita em comparação ao sistema convencional.The effect of a technological package implemented in a Valencia orange orchard was studied and compared with the conventional system, based on the production and quality of the fruits harvested. The technologies implemented included the densification, fertilization during implantation and training, phytosanitary treatment, weed management, irrigation and pruning. The results for the fruits from the first harvest showed that the Technified System and Irrigation (TS + I resulted in significant increase in crop yield. This increase was higher in orchards with a higher density of 727 plants ha-1 (5.5 x 2.5 m spacing or 667 plants ha-1 (6.0 x 2.5 m spacing. In general, irrigation concomitant with TS

  3. The Cultivation of Wisdom in the Classroom

    Directory of Open Access Journals (Sweden)

    Juliane Reams

    2015-03-01

    Full Text Available This article focuses on a research project that was designed to inquire into the cultivation of wisdom in the classroom in the context of a newly implemented school subject called Glück (English: happiness. Glück was introduced in order to make a difference in traditional mainstream schooling as a reaction to school curricula that emphasize data and knowledge transfer. It is different and new because it embraces the kind of learning that includes the senses, the mind, body, spirit and the guts. Its multidimensional approach makes an attempt to validate a renunciation of the reductionistic perspective of traditional and contemporary schooling. How it is implemented served as a transformational process through a set of experiential exercises, group discussions, contemplative practices, teamwork etc. It is my aim to give an insight into what I understood as an alternative learning arena embedded in a traditional schooling system and the implications for further development beyond the transfer of data and information in adolescents. Zooming in on Glück, I aim to provide some perspectives on how key experiences and the reflection upon them can lead to the cultivation of wisdom. The understanding of cultivating wisdom I have gained from this study is that it is a dynamic process where the creation of new structures of meaning making emerge through the interaction with others, with oneself and the reflection upon one’s own interior processes that can help unfold, know how to use and refine tacit knowledge. Part of this process is actively discovering and transforming complex information in order to embody it and make it one’s own. Due to the assumption that traditional schooling mostly puts an emphasis on conveying informational knowledge (Hart, 2009; Sternberg, 2001 (to the more or less attentive students and another assumption that wisdom is often seen in connection to age, this article makes an attempt to give an alternative perspective. In

  4. Can agricultural Cultivation Methods Influence the Healthfulness of Crops for Foods?

    DEFF Research Database (Denmark)

    Melballe Jensen, Maja; Jørgensen, Henry; Halekoh, Ulrich

    2012-01-01

    The aim of the current study was to investigate if there are any health effects of long-term consumption of organically grown crops using a rat model. Crops were retrieved over two years from a long-term field trial at three different locations in Denmark, using three different cultivation systems....... Additionally, the nutritional quality was affected by harvest year and location. However, harvest year and location rather than cultivation system affected the measured health biomarkers. In conclusion, the differences in dietary treatments composed of ingredients from different cultivation systems did...... not lead to significant differences in the measured health biomarkers, except for a significant difference in plasma IgG levels....

  5. Teor de nitrato em alface cultivada em sistemas hidropônico e convencional Level of nitrate in lettuce cultivated in hydroponic and conventional systems

    Directory of Open Access Journals (Sweden)

    Elisabete R. Yonamini Beninni

    2002-06-01

    Full Text Available O monitoramento do teor de nitrato nos alimentos é importante, uma vez que poderão ser formados compostos prejudiciais à saúde humana e animal após sua ingestão. Com o objetivo de avaliar o teor de nitrato presente em alface, foram coletadas e analisadas as folhas de alface crespa comercializada no Município de Londrina, cultivada em sistemas hidropônico e convencional. Os valores encontrados variaram entre 26 e 2.568 mg.kg-1 de peso fresco, sendo que as plantas cultivadas em sistema hidropônico apresentaram teores superiores em relação às cultivadas em sistema convencional, porém abaixo do limite máximo de nitrato permitido para alface, na Europa.The control of the nitrate level in foods is important because this substance may be harmful to human and animal health. The aim of this work was to evaluate nitrate levels in lettuce produced in hydroponic and conventional systems and commercialized in Londrina, Brazil. The nitrate concentration ranged from 26 to 2,568 mg.kg-1 fresh weight. Hydroponic lettuce showed higher levels of nitrate but in all cases the level of nitrate was lower than the maximum allowed by the Comission of the European Communities.

  6. Multiple outcomes of cultivation in the Sahel

    DEFF Research Database (Denmark)

    Rasmussen, Laura Vang; Reenberg, Anette

    2015-01-01

    A default assumption about the Sahel is that farmers consider food provision for the family as the sole reason for cultivation. The degree to which this ‘cultivation for food’ assumption has been embedded in the scientific literature on land use changes is signified by the fact that hardly any...

  7. Shifting Cultivation : Promoting Innovative Policy and Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Shifting Cultivation : Promoting Innovative Policy and Development Options in the Eastern Himalayas. Shifting ... pressure and market forces. The idea is to share good policies and practices related to shifting cultivation and alternative options through regional exchange. ... Les chaînes de valeur comme leviers stratégiques.

  8. Life cycle assessment: an application to poplar for energy cultivated in Italy

    OpenAIRE

    Bacenetti, J.; Gonzalez Garcia, S.; Mena, A.; Fiala, M.

    2012-01-01

    The development of the bioenergy sector has led to an increasing interest in energy crops. Short rotation coppices (SRC) are forestry management systems in which fast-growing tree species are produced under intensive cultivation practices to obtain high wood chips yields. In Italy, most SRC plantations consist of poplar biomass-clones. SRC plantations can be carried out with different management systems with diverse cutting times; consequently, the cultivation system can be crucial for attain...

  9. Cultivo de girassol em sistema hidropônico sob diferentes níveis de salinidade Sunflower cultivation in a hydroponic system under different salinity levels

    Directory of Open Access Journals (Sweden)

    José Amilton Santos Júnior

    2011-12-01

    Full Text Available Os sistemas hidropônicos tem se constituído em uma das alternativas para equacionar os fatores naturais adversos à produção agropecuária presentes nas regiões semiáridas do Brasil, como solos rasos, pedregosos e pouco férteis, além da escassez de recursos hídricos em quantidade e qualidade (teores elevados de sais. Este trabalho buscou estudar os componentes de produção do girassol (variedade EMBRAPA 122/V-2000 destinados à obtenção de aquênios e forragem (fitomassa, cultivado em sistema hidropônico, utilizando a fibra de coco como substrato e irrigado com água salobra de diferentes salinidades. O delineamento experimental utilizado foi o inteiramente casualizado, em esquema fatorial 5 x 2 com três repetições, de modo que foram estudados cinco níveis de salinidade e duas densidades de plantio - uma ou duas plantas por vaso. As águas de irrigação foram compostas por 50% da solução nutritiva padrão e 50% de água de abastecimento, adicionada de níveis crescentes de NaCl, resultando em uma condutividade elétrica final da solução (CEs de 1,7; 4,3; 6,0; 9,0 e 11,5 dS m-1. Verificou-se que a densidade diferenciada das plantas de girassol afetou positivamente os componentes de produção de aquênios e fitomassa da cultura indicando maior viabilidade quando se utiliza duas plantas por vaso.Hydroponic systems have constituted an alternative for combating the adverse natural factors of agricultural production in the semi-arid regions of Brazil, such as shallow rocky and infertile soils, and the scarcity of good quality water resources (high salt content. This work studied the yield of the sunflower (variety EMBRAPA 122/V-2000 destined for achene and fodder (phytomass production, grown hydroponically, using coconut fiber as substrate and irrigated with brackish water of varying salinities. The experimental layout used was completely randomized into a 5 x 2 factorial design with three replications, five levels of water

  10. Intensification of Shifting Cultivation in Tanzania: Degree, Drivers and Effects on Vegetation and Soils

    DEFF Research Database (Denmark)

    Kilawe, Charles Joseph

    The aim of the present study was to provide a better understanding of the degree and drivers of intensification of shifting cultivation and its effects on vegetation and soils. The study was conducted in uplands and low lands agro-ecological zones of Kilosa District, eastern central Tanzania. Data...... and intensive short fallow systems. They also adopted intensive land preparation methods that involved deep cultivation and burying of vegetation. Intensification in upland was driven by adoption and enforcement of land tenure policies which restrict shifting cultivation whereas in the lowlands, it was driven...... that sustainable intensification of shifting cultivation be sought to prevent further adverse effects on the environment. The present restrictive policy driven approach of intensification of shifting cultivation seems to cause more negative environmental consequences. I recommend development and promotion...

  11. Variabilidad temporal de algunas propiedades químicas en un suelo sometido a distintas sucesiones de cultivo Temporal variability of chemical properties in a soil with three cultivation systems

    Directory of Open Access Journals (Sweden)

    Orozimbo Silveira Carvalho

    1999-12-01

    Full Text Available El presente trabajo ha sido realizado en la Finca Experimental "La Poveda" en Arganda del Rey (Madrid, con las siguientes coordenadas geográficas: latitud 40º19' N; longitud 3º19' W Gr; y altitud 550 m. El objetivo principal consiste en el estudio de la variabilidad temporal de algunas propiedades químicas en un suelo sometido a distintas sucesiones de cultivo. Para el estudio de la variabilidad temporal de las características químicas el muestreo se realizó en los meses de febrero y septiembre de 1993 y febrero y septiembre de 1994. La materia orgánica del sistema Prado/Veza-Avena presenta el menor coeficiente de variación con respecto a los sistemas monocultivo de Cebada y Veza-Avena/Girasol. El menor contenido de materia orgánica a lo largo del tiempo lo presenta el sistema Cebada/Cebada. Los sistemas Prado/Veza-Avena y Veza-Avena/Girasol presentaron contenidos de materia orgánica 42,86% y 40,54% superiores al del sistema Cebada/Cebada.This study has been carried out at the Experimental Station "La Poveda" in Arganda del Rey (Madrid, with the following geographical coordinates: latitude 40º19' N; longitude 3º19' W Gr; and altitude 550 m. The main objective was to study the temporal variability of chemical properties in a soil with three cultivation systems. In order to study variation with time of chemical characteristics, samples were taken in February and September 1993 and February and September 1994. Organic matter content in the prairie/vetch-oat system had the smallest variation coefficient with respect to barley and vetch-oat/sunflower systems. Along with the time the barley/barley system presented a lower organic matter content. The crop systems pasture/vetch-oat and vetch-oat/sunflower presented an organic matter content 42.86 and 40.54% higher than that presented by barley/barley system, respectively.

  12. Recent advances in periodontal microbiology: An update on cultivation techniques

    Directory of Open Access Journals (Sweden)

    Kishore G Bhat

    2014-01-01

    Full Text Available Microbial members of the subgingival plaque community play a major role in the initiation and progression of periodontal diseases. Majority of these bacteria are anaerobic in nature and several anaerobic systems have been used for their cultivation. Among them anaerobic jars are the most popular and are routinely used for the detection of periodontal pathogens from clinical samples. Despite best efforts, a significant portion of oral microbes have not yet been cultivated and several hypotheses have been put forth to explain this anomaly. This has led to renewed efforts to cultivate the oral bacteria so far identified only by their molecular signatures resulting in improvisation of existing culture techniques and devising novel methods of isolation. Several devices have been used on environmental samples successfully: One method called "minitrap" has been successfully adapted to oral cavity and has shown great promise in isolation of not yet cultivated oral bacterial species. These newer techniques are sure to shed more light on the role of microbes in the etiology of periodontal diseases.

  13. Microalgal composition and primary production in Arctic sea ice: a seasonal study from Kobbeijord (Kangerluarsunnguaq), West Greenland

    DEFF Research Database (Denmark)

    Mikkelsen, Ditte Marie; Rysgaard, Søren; Glud, Ronnie N.

    2008-01-01

    We investigated the microalgal community in sea ice and in the water column of Kobbefjord, west Greenland, through an entire sea ice season, Temporal variation in physical (photosynthetically active radiation [PAR), temperature, brine volume) and chemical (salinity, nutrient concentration......) properties confirmed that sea ice is a very dynamic habitat. Nevertheless, a viable sea ice algal comuunity was present throughout the year, with a species succession from flagellate dominance (dinoflagellates and cryptophytes) in December to February, followed by Chaetoceros simplex (a centric diatom...... (maxima of 1.8 and 2.6 mu g chl](-1) in March and May, respectively). Primary production mirrored biomass dynamic, which had 2 seasonal peaks of ca. 21 and 15 mg Cm-2 d(-1). Integrated primary production over 7 mo was 0.8 g Cm-2 in sea ice and 94.4 g C m(-2) in the water column, with the vast majority...

  14. Microalgal composition and primary production in Arctic sea ice: a seasonal study from Kobbeijord (Kangerluarsunnguaq), West Greenland

    DEFF Research Database (Denmark)

    Mikkelsen, Ditte Marie; Rysgaard, Søren; Glud, Ronnie N.

    2008-01-01

    We investigated the microalgal community in sea ice and in the water column of Kobbefjord, west Greenland, through an entire sea ice season, Temporal variation in physical (photosynthetically active radiation [PAR), temperature, brine volume) and chemical (salinity, nutrient concentration...... (maxima of 1.8 and 2.6 mu g chl](-1) in March and May, respectively). Primary production mirrored biomass dynamic, which had 2 seasonal peaks of ca. 21 and 15 mg Cm-2 d(-1). Integrated primary production over 7 mo was 0.8 g Cm-2 in sea ice and 94.4 g C m(-2) in the water column, with the vast majority......) properties confirmed that sea ice is a very dynamic habitat. Nevertheless, a viable sea ice algal comuunity was present throughout the year, with a species succession from flagellate dominance (dinoflagellates and cryptophytes) in December to February, followed by Chaetoceros simplex (a centric diatom...

  15. Recovery of Silver Using Adsorption Gels Prepared from Microalgal Residue Immobilized with Functional Groups Containing Sulfur or Nitrogen

    Directory of Open Access Journals (Sweden)

    Kanjana Khunathai

    2017-06-01

    Full Text Available Although biodiesel oil extracted from microalgae attracts much attention as one of the most promising green energies, its high production cost is a big problem, impeding its extensive use. In order to lower the production cost, the effective use of microalgal residue after extracting biofuel was investigated as a feed material of functional materials. In the present work, a new adsorbent for silver(I was prepared by immobilizing functional groups of polyethylene-polyamine or dithiooxamide, which exhibita high affinity for soft Lewis acids such as silver(I ions. Their adsorption behaviors for silver(I were investigated from aqueous nitrate and acidothiourea media. The effects of the concentrations of nitrate and thiourea, as well as of sulfuric acid, were qualitatively interpreted. From the study of adsorption isotherms on these gels, they were found to exhibita higher adsorption capacity than the majority of those reported to date.

  16. Economic and energy assessment of minimalized soil tillage methods in maize cultivation

    OpenAIRE

    Piotr Szulc; Andrzej Dubas

    2014-01-01

    Grain yield of maize cultivated in the years 1997-2009 in monoculture and with annual tillage simplifications was assessed in energy and economy terms. Effects of no-tillage system and direct sowing (D) with cultivation with autumn deep (A) and shallow (B) ploughing and cultivation with spring pre-sowing ploughing (C) were compared. It was demonstrated that the 13-year maize grain yield in no-tillage system and direct sowing was lower by 10.4% than the yield obtained in conventional tillage s...

  17. Uva "Niágara Rosada" cultivada no sistema orgânico e armazenada em diferentes temperaturas "Niágara Rosada" grapes cultivated under organic system and stored at different temperatures

    Directory of Open Access Journals (Sweden)

    Alessandra M. Detoni

    2005-09-01

    Full Text Available O sistema de cultivo, as cultivares, as condições de colheita e pós-colheita têm efeito direto na conservação e qualidade das uvas. Diante disso, este trabalho objetivou avaliar o efeito do tempo (0, 7, 14, 21, 28 e 35 dias e da temperatura de armazenamento (1, 14 e 24ºC na qualidade pós-colheita da uva "Niágara Rosada" cultivada no sistema orgânico. O fator limitante para o armazenamento foi o elevado índice de degrana, porém, as uvas ainda possuíam qualidade para o consumo, por observar a manutenção do teor de sólidos solúveis totais, acidez total titulável e pH. Dentre as avaliações químicas, o teor de sólidos solúveis totais, a acidez total titulável e o teor de vitamina C foram as únicas variáveis que apresentaram diminuição acentuada para as frutas armazenadas a 24ºC, resultando em um curto período de armazenamento. As frutas armazenadas a 14ºC não apresentaram grandes variações nas características químicas, mantendo uma boa qualidade para o consumo por até 28 dias de armazenamento. A melhor temperatura para a conservação das frutas foi 1ºC, em que as uvas alcançaram 35 dias de armazenamento sem grande variação na qualidade para o consumo.The cultivation system, the cultivars, the crop conditions and post harvest, can effect the conservation and quality of the grapes. This work aimed the evaluation of the affect of the time of storage (0, 7, 14, 21, 28 and 35 days and the storage temperature (1, 14 and 24ºC in the quality of the grape "Niágara Rosada" pots harvest cultivated in the organic system. The limiting point for the storage was the high number of free berries observed, however the grapes still have quality for consumption, because observing without modification in the tenor of total soluble, the total titratable acidity and pH. Among the chemical assay, the determination of the tenor of total soluble solids, the total titratable acidity and the vitamin tenor C were the only ones which

  18. Fenologia da goiabeira 'Paluma' sob diferentes sistemas de cultivos, épocas e intensidades de poda de frutificação Phenology of 'Paluma' guava trees under different cultivation systems, times and intensities of fruit pruning

    Directory of Open Access Journals (Sweden)

    Luiz Augusto Lopes Serrano

    2008-01-01

    Full Text Available O trabalho teve como objetivo avaliar os efeitos de diferentes épocas e intensidades de poda de frutificação sobre a fenologia da goiabeira 'Paluma', em dois sistemas de cultivo, em Pedro Canário (ES. O delineamento experimental foi o de blocos ao acaso, em esquema de parcelas sub-subdivididas. As parcelas foram os sistemas de cultivo irrigado e sequeiro; as subparcelas foram as épocas de poda (10/11/2005, 9/12/2005, 13/1/2006 e 10/2/2006; e as sub-subparcelas foram as intensidades de poda (curta, média e longa. O ciclo da goiabeira 'Paluma', entre a poda até o início da colheita dos frutos, variou de 182 (poda em novembro e dezembro a 203 dias (poda em fevereiro. A queda fisiológica dos frutos ocorreu até os 56 dias após o final do florescimento. A irrigação e a poda longa proporcionaram maior brotação e estabelecimento dos ramos. As plantas submetidas à poda longa em fevereiro produziram maior número de frutos por ramo. Independentemente da época de poda, as plantas submetidas à poda curta apresentaram menor número de frutos por ramo e menor índice de pegamento de frutos. A irrigação e as podas realizadas em dezembro e janeiro favoreceram a produção de frutos maiores.The objective of this work was to evaluate the effects of different fruit pruning times and intensities on the phenology of 'Paluma' guava trees in two cultivation systems, in Pedro Canário, Espírito Santo State, Brazil. The experimental design was a randomized complete block in a split split plots scheme. The main plots were the cultivation systems (with and without irrigation, the split plots were the pruning times (November 10, 2005; December 9, 2005; January 13, 2006 and February 10, 2006, and the split split plots were the pruning intensities (heavy, medium and light. The period between pruning and the beginning of fruit ripening was between 182 (pruning in November and December to 203 days (pruning in February. Fruit physiologic fall continued for

  19. Anita: cultivar de alface de verão para cultivo protegido no solo e em hidroponia 'Anita': a new summer lettuce cultivar suitable for protected cultivation in soil and hydroponics systems

    Directory of Open Access Journals (Sweden)

    Ernani Clarete da Silva

    2009-06-01

    Full Text Available 'Anita' é uma cultivar de alface (Lactuca sativa L. do grupo lisa, de cor verde-clara intensa, cujo desenvolvimento se deu a partir de 1994 no município de Campos dos Goytacazes, RJ. Foi selecionada pelo método genealógico a partir do cruzamento entre as cultivares comerciais Vitória e Brasil 303. As plantas contêm diâmetro médio de cabeça de 55 cm, massa fresca de 700 g e número médio de 55 folhas, conforme resultados de ensaios conduzidos nas quatro estações do ano. Possui resistência ao LMV e ao pendoamento precoce em cultivos de verão. As folhas são grandes, macias, crocrantes e adocicadas, sendo estas características mantidas tanto no cultivo protegido no solo quanto em hidroponia.'Anita' is a lettuce cultivar (Lactuca sativa L. of the loose-leaf group whose leaves are of intense green color. This cv. was developed in Campos dos Goytacazes, Rio de Janeiro State, Brazil, since 1994. "Anita" was selected by the pedigree method through crossings between commercial cultivars Vitória and Brasil 303. After evaluations done during four seasons, there were detected a head mean diameter around 55 cm, average fresh plant weight of 700 g and 55 leaves in average. Plants present resistance to Lettuce Mosaic Virus (LMV and high resistance to bolting in the summer. In both cultivation systems, protected environment or hydroponics, plants present leaves of great size, soft and sweet.

  20. Submerged cultivation of medicinal mushrooms: bioprocesses and products (review).

    Science.gov (United States)

    Elisashvili, Vladimir

    2012-01-01

    Medicinal mushrooms belonging to higher Basidiomycetes are an immensely rich yet largely untapped resource of useful, easily accessible, natural compounds with various biological activities that may promote human well-being. The medicinal properties are found in various cellular components and secondary metabolites (polysaccharides, proteins and their complexes, phenolic compounds, polyketides, triterpenoids, steroids, alkaloids, nucleotides, etc.), which have been isolated and identified from the fruiting bodies, culture mycelium, and culture broth of mushrooms. Some of these compounds have cholesterol-lowering, anti-diabetic, antioxidant, antitumor, immunomodulating, antimicrobial, and antiviral activities ready for industrial trials and further commercialization, while others are in various stages of development. Recently, the submerged cultivation of medicinal mushrooms has received a great deal of attention as a promising and reproducible alternative for the efficient production of mushroom mycelium and metabolites. Submerged cultivation of mushrooms has significant industrial potential, but its success on a commercial scale depends on increasing product yields and development of novel production systems that address the problems associated with this technique of mushroom cultivation. In spite of many researchers' efforts for the production of bioactive metabolites by mushrooms, the physiological and engineering aspects of submerged cultures are still far from being thoroughly studied. The vast majority of studies have focused on polysaccharide and ganoderic acid production in submerged cultivation of medicinal mushrooms, and very little has been written so far on the antioxidant and hemagglutinating activity of submerged mushroom cultures. The purpose of this review is to provide an update of the present state of the art and future prospects of submerged cultivation of medicinal mushrooms to produce mycelium and bioactive metabolites, and to make a

  1. Genotipagem de polimorfismos associados com sistemas de macho-esterilidade em acessos de cebola adaptados ao Brasil Genotyping of polymorphisms associated with male-sterility systems in onion accessions adapted for cultivation in Brazil

    Directory of Open Access Journals (Sweden)

    Carlos Francisco Ragassi

    2012-09-01

    Full Text Available A produção em escala comercial de sementes híbridas de cebola (Allium cepa tem sido conduzida com o emprego de dois sistemas de macho-esterilidade do tipo genética-citoplasmática (CMS-S e CMS-T em associação ao citoplasma normal (macho-fértil. No entanto, a análise molecular desses diferentes tipos citoplasmáticos ainda não está disponível para um grande número de acessos de cebola adaptados para cultivo em regiões tropicais. Além de adaptação às condições edafoclimáticas do Brasil, muitos desses acessos apresentam tolerância a doenças, sendo de potencial valor como genitores de híbridos. O presente trabalho visou identificar os tipos citoplasmáticos de acessos de cebola de diferentes grupos morfoagronômicos de interesse para o melhoramento genético no Brasil, usando a reação da polimerase em cadeia (PCR com 'primers' específicos para regiões polimórficas do genoma mitocondrial de cebola. Foi observada, nos 66 acessos amostrados, a presença dos três principais tipos de citoplasma descritos para cebola (S, N e T. Foi constatada maior frequência do citoplasma S (56% seguido do citoplasma T (25,8%. Em 18,2% das amostras, foi encontrado exclusivamente o citoplasma N. Essa caracterização pode ser útil para guiar a escolha de materiais genéticos dentro dos programas de melhoramento com objetivo de desenvolver cultivares híbridas adaptadas às condições tropicais.The synthesis of onion (Allium cepa hybrids relies upon the use of two genetic-cytoplasmic male-sterility systems, CMS-S and CMS-T, in association to the normal male-fertile (N cytoplasm. However, the molecular phenotyping of male-sterility-inducing and normal cytoplasms of many onion accessions adapted for cultivation under tropical conditions is not available. Some of these accessions were reported as presenting tolerance to diseases and adaptation to tropical and subtropical regions. Therefore, these accessions are potential sources of parental

  2. Desempenho agronômico de linhas endogâmicas recombinadas de pimenta em dois sistemas de cultivo Agronomic performance of recombinant chili pepper inbred lines in two cultivation systems

    Directory of Open Access Journals (Sweden)

    Sarah Ola Moreira

    2009-08-01

    .Climate and management diversity play an important role in crop production, since these characteristics are related to genotype and cultivation environment. The aim of this study was to evaluate the effects of genotype, environment and genotype-environmental interaction (GE in 12 recombinant inbred lines of C. annuum. These lines were originated from crosses between the following accessions: a sweet pepper cultivar (susceptible to bacterial spot and a chili pepper (resistant to bacterial spot. Two tests were conducted, the first in a conventional agriculture system, under field conditions and the second in ecological or organic system, under greenhouse conditions. The field experiment was carried out in Campos dos Goytacazes, RJ. The greenhouse experiment was conducted in Seropédica, RJ. Both experiments were performed using a randomized block design with three replications. The measured variables were total fruit number (TFN; total fruit weight (TFW; mean fruit weight (MFW; fruit length (FL; fruit diameter (FD; length/diameter fruit ratio (FL/FD and capsaicin presence (CAPS. Data obtained for each experimental condition were submitted to variance analysis, joint variance analysis, and partitioning of genotype environment interaction. Genotype and GE quadratic components, genotypic determination coefficient, genetic variation coefficient and variation index were determined. The GE interaction was significant for TFN, TFW, MFN, FD, and FL/FD. Cultivation under greenhouse conditions was responsible for the highest mean performance for every trait studied but FL. Values observed for genetic variation were greater than values obtained for environmental variation. For field conditions, the high yield ability observed for line 2 (pungent is suggestive of a potential to be used as a commercial genotype. For greenhouse conditions, line 8 (pungent, had higher fruit number yield. Line 1 (non-pungent also seems promising for commercial cultivation under both conditions.

  3. A global view of shifting cultivation: Recent, current, and future extent.

    Directory of Open Access Journals (Sweden)

    Andreas Heinimann

    Full Text Available Mosaic landscapes under shifting cultivation, with their dynamic mix of managed and natural land covers, often fall through the cracks in remote sensing-based land cover and land use classifications, as these are unable to adequately capture such landscapes' dynamic nature and complex spectral and spatial signatures. But information about such landscapes is urgently needed to improve the outcomes of global earth system modelling and large-scale carbon and greenhouse gas accounting. This study combines existing global Landsat-based deforestation data covering the years 2000 to 2014 with very high-resolution satellite imagery to visually detect the specific spatio-temporal pattern of shifting cultivation at a one-degree cell resolution worldwide. The accuracy levels of our classification were high with an overall accuracy above 87%. We estimate the current global extent of shifting cultivation and compare it to other current global mapping endeavors as well as results of literature searches. Based on an expert survey, we make a first attempt at estimating past trends as well as possible future trends in the global distribution of shifting cultivation until the end of the 21st century. With 62% of the investigated one-degree cells in the humid and sub-humid tropics currently showing signs of shifting cultivation-the majority in the Americas (41% and Africa (37%-this form of cultivation remains widespread, and it would be wrong to speak of its general global demise in the last decades. We estimate that shifting cultivation landscapes currently cover roughly 280 million hectares worldwide, including both cultivated fields and fallows. While only an approximation, this estimate is clearly smaller than the areas mentioned in the literature which range up to 1,000 million hectares. Based on our expert survey and historical trends we estimate a possible strong decrease in shifting cultivation over the next decades, raising issues of livelihood security

  4. Quantification of net carbon flux from plastic greenhouse vegetable cultivation: A full carbon cycle analysis

    International Nuclear Information System (INIS)

    Wang Yan; Xu Hao; Wu Xu; Zhu Yimei; Gu Baojing; Niu Xiaoyin; Liu Anqin; Peng Changhui; Ge Ying; Chang Jie

    2011-01-01

    Plastic greenhouse vegetable cultivation (PGVC) has played a vital role in increasing incomes of farmers and expanded dramatically in last several decades. However, carbon budget after conversion from conventional vegetable cultivation (CVC) to PGVC has been poorly quantified. A full carbon cycle analysis was used to estimate the net carbon flux from PGVC systems based on the combination of data from both field observations and literatures. Carbon fixation was evaluated at two pre-selected locations in China. Results suggest that: (1) the carbon sink of PGVC is 1.21 and 1.23 Mg C ha -1 yr -1 for temperate and subtropical area, respectively; (2) the conversion from CVC to PGVC could substantially enhance carbon sink potential by 8.6 times in the temperate area and by 1.3 times in the subtropical area; (3) the expansion of PGVC usage could enhance the potential carbon sink of arable land in China overall. - Highlights: → We used full carbon (C) cycle analysis to estimate the net C flux from cultivation. → The plastic greenhouse vegetable cultivation system in China can act as a C sink. → Intensified agricultural practices can generate C sinks. → Expansion of plastic greenhouse vegetable cultivation can enhance regional C sink. - The conversion from conventional vegetable cultivation to plastic greenhouse vegetable cultivation could substantially enhance carbon sink potential by 8.6 and 1.3 times for temperate and subtropical area, respectively.

  5. Design of an SolidWorks-based household substrate cultivation device

    Science.gov (United States)

    Yi, Guo; Yueying, Wang

    2018-03-01

    Rapid urbanization has caused increasingly severe environmental problems and smaller tillable land area. Even worse, negative reports on vegetable production are repeatedly found. In this case, home gardening has become an inexorable trend. To meet demand for vegetable cultivation in the home environment, an SolidWorks-based household substrate cultivation device has been designed. This device is composed of the cultivation tank, upright post, base, irrigation system, supplemental lighting system and control system. The household substrate cultivation device manufactured based on the design results has shown in practice that this device features an esthetic appearance, low cost, automatic irrigation and lighting supplementation, good vegetable growing conditions, full of ornamental value and practicability and thus is suitable for vegetable growing in the home environment. Hence it has a higher promotion value in the home gardening field.

  6. Cultivation of parasitic leptospires: effect of pyruvate.

    Science.gov (United States)

    Johnson, R C; Walby, J; Henry, R A; Auran, N E

    1973-07-01

    Sodium pyruvate (100 mug/ml) is a useful addition to the Tween 80-albumin medium for the cultivation of parasitic serotypes. It is most effective in promoting growth from small inocula and growth of the nutritionally fastidious serotypes.

  7. Advancing gut microbiome research using cultivation

    DEFF Research Database (Denmark)

    Sommer, Morten OA

    2015-01-01

    Culture-independent approaches have driven the field of microbiome research and illuminated intricate relationships between the gut microbiota and human health. However, definitively associating phenotypes to specific strains or elucidating physiological interactions is challenging for metagenomic...... approaches. Recently a number of new approaches to gut microbiota cultivation have emerged through the integration of high-throughput phylogenetic mapping and new simplified cultivation methods. These methodologies are described along with their potential use within microbiome research. Deployment of novel...... cultivation approaches should enable improved studies of xenobiotic tolerance and modification phenotypes and allow a drastic expansion of the gut microbiota reference genome catalogues. Furthermore, the new cultivation methods should facilitate systematic studies of the causal relationship between...

  8. How to Cultivate the Student's Cultural Awareness

    Institute of Scientific and Technical Information of China (English)

    tian xiu ying

    2008-01-01

    Language and culture are inseparable and cultural awareness must be integrated with language teaching. How to cultivate the learners' cultural awareness is an important issue that we have to carry out in teaching practice in China.

  9. Cultivation of Chlorella vulgaris JSC-6 with swine wastewater for simultaneous nutrient/COD removal and carbohydrate production.

    Science.gov (United States)

    Wang, Yue; Guo, Wanqian; Yen, Hong-Wei; Ho, Shih-Hsin; Lo, Yung-Chung; Cheng, Chieh-Lun; Ren, Nanqi; Chang, Jo-Shu

    2015-12-01

    Swine wastewater, containing a high concentration of COD and ammonia nitrogen, is suitable for the growth of microalgae, leading to simultaneous COD/nutrients removal from the wastewater. In this study, an isolated carbohydrate-rich microalga Chlorella vulgaris JSC-6 was adopted to perform swine wastewater treatment. Nearly 60-70% COD removal and 40-90% NH3-N removal was achieved in the mixotrophic and heterotrophic culture, depending on the dilution ratio of the wastewater, while the highest removal percentage was obtained with 20-fold diluted wastewater. Mixotrophic cultivation by using fivefold diluted wastewater resulted in the highest biomass concentration of 3.96 g/L. The carbohydrate content of the microalga grown on the wastewater can reach up to 58% (per dry weight). The results indicated that the microalgae-based wastewater treatment can efficiently reduce the nutrients and COD level, and the resulting microalgal biomass had high carbohydrate content, thereby having potential applications for the fermentative production of biofuels or chemicals. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Effectiveness of Training Programme on Mushroom Cultivation

    OpenAIRE

    Rahman, Md. Sazzadur; Hossain, Kh. Zulfikar; Ali, Md. Sekender; Afroz, Fauzia

    2017-01-01

    Effectiveness is one of the key parameters to assess success of any programs. However, the effectiveness of training programme on mushroom cultivation was not well addressed. The purposes of this study were to investigate the effectiveness of training programme on mushroom cultivation and to explore the relationships of each of the selected characteristics of the trained mushroom farmers with their effectiveness of training programme. Data were collected from the trained mushroom farmers of s...

  11. High-throughput, label-free, single-cell, microalgal lipid screening by machine-learning-equipped optofluidic time-stretch quantitative phase microscopy.

    Science.gov (United States)

    Guo, Baoshan; Lei, Cheng; Kobayashi, Hirofumi; Ito, Takuro; Yalikun, Yaxiaer; Jiang, Yiyue; Tanaka, Yo; Ozeki, Yasuyuki; Goda, Keisuke

    2017-05-01

    The development of reliable, sustainable, and economical sources of alternative fuels to petroleum is required to tackle the global energy crisis. One such alternative is microalgal biofuel, which is expected to play a key role in reducing the detrimental effects of global warming as microalgae absorb atmospheric CO 2 via photosynthesis. Unfortunately, conventional analytical methods only provide population-averaged lipid amounts and fail to characterize a diverse population of microalgal cells with single-cell resolution in a non-invasive and interference-free manner. Here high-throughput label-free single-cell screening of lipid-producing microalgal cells with optofluidic time-stretch quantitative phase microscopy was demonstrated. In particular, Euglena gracilis, an attractive microalgal species that produces wax esters (suitable for biodiesel and aviation fuel after refinement), within lipid droplets was investigated. The optofluidic time-stretch quantitative phase microscope is based on an integration of a hydrodynamic-focusing microfluidic chip, an optical time-stretch quantitative phase microscope, and a digital image processor equipped with machine learning. As a result, it provides both the opacity and phase maps of every single cell at a high throughput of 10,000 cells/s, enabling accurate cell classification without the need for fluorescent staining. Specifically, the dataset was used to characterize heterogeneous populations of E. gracilis cells under two different culture conditions (nitrogen-sufficient and nitrogen-deficient) and achieve the cell classification with an error rate of only 2.15%. The method holds promise as an effective analytical tool for microalgae-based biofuel production. © 2017 International Society for Advancement of Cytometry. © 2017 International Society for Advancement of Cytometry.

  12. Phytoplanktonic composition of three cultivation systems used in Litopenaeus vannamei (BOONE, 1931 marine shrimp farms = Composição fitoplanctônica em três sistemas de cultivo do camarão marinho Litopenaeus vannamei (BOONE, 1931

    Directory of Open Access Journals (Sweden)

    Michelle Pereira Melo

    2010-07-01

    Full Text Available The aim of this work is to assess the different compositions of phytoplankton in three cultivation systems of marine shrimps Litopenaeus vannamei (BOONE, 1931, denominated as organic, intensive and semi intensive. The samples were done fortnightly, when phytoplankton was collected by a net for phytoplankton, 65 ƒÊm mesh, being then filtrated in a total volume of water of 100 L, and preserved in formaldehyde solution at 4% and identified according to the methodology of Cordeiro et al. (1997. The results show that the densities of Diatoms were of 16.65, 10.47 and 7.57 cel. 103 mL-1 for the organic, intensive and semi intensive cultivations, respectively. As for cyanobacteria, the average figures were 42.06 cel. 103 mL-1 forsemi intensive 17.27 cel. 103 mL-1, in the intensive cultivation and 6.11 cel. 103 mL-1 for the organic cultivation system. The dinoflagellates had the highest cellular density in the phytoplankton community analyzed with 61.9 cel. 103 mL-1 in the intensive cultivation, 0.33 and 0.03 cel. 103 mL-1 for both semi intensive and organic cultivation systems respectively. Euglenas presented the results of 4.98 and 14.86 cel. 103 mL-1 only for semi intensive and intensive cultivations. It was then concluded that all cultivations presented average rates below recommended for such studied systems.Conduziu-se esse trabalho com o objetivo de avaliar as diferentes composicoes fitoplanctonicas em tres sistemas de cultivo para o camarao marinho Litopenaeus vannamei (BOONE, 1931, denominados de organico, intensivo e semiintensivo. As amostragens foram realizadas quinzenalmente, onde o fitoplancton foi coletado atraves de uma rede de plancton, com malha de 65 ƒÊm, sendo filtrado um volume de agua total de 100 litros, que foram preservadas em solucao de formol a 4% e identificadas segundo a metodologia de Cordeiro et al. (1997. Os resultados mostram que as densidades de diatomaceas foram de 16,65; 10,47 e 7,57 cel. 103 mL-1, respectivamente

  13. Raman-Activated Droplet Sorting (RADS) for Label-Free High-Throughput Screening of Microalgal Single-Cells.

    Science.gov (United States)

    Wang, Xixian; Ren, Lihui; Su, Yetian; Ji, Yuetong; Liu, Yaoping; Li, Chunyu; Li, Xunrong; Zhang, Yi; Wang, Wei; Hu, Qiang; Han, Danxiang; Xu, Jian; Ma, Bo

    2017-11-21

    Raman-activated cell sorting (RACS) has attracted increasing interest, yet throughput remains one major factor limiting its broader application. Here we present an integrated Raman-activated droplet sorting (RADS) microfluidic system for functional screening of live cells in a label-free and high-throughput manner, by employing AXT-synthetic industrial microalga Haematococcus pluvialis (H. pluvialis) as a model. Raman microspectroscopy analysis of individual cells is carried out prior to their microdroplet encapsulation, which is then directly coupled to DEP-based droplet sorting. To validate the system, H. pluvialis cells containing different levels of AXT were mixed and underwent RADS. Those AXT-hyperproducing cells were sorted with an accuracy of 98.3%, an enrichment ratio of eight folds, and a throughput of ∼260 cells/min. Of the RADS-sorted cells, 92.7% remained alive and able to proliferate, which is equivalent to the unsorted cells. Thus, the RADS achieves a much higher throughput than existing RACS systems, preserves the vitality of cells, and facilitates seamless coupling with downstream manipulations such as single-cell sequencing and cultivation.

  14. Desarrollo vegetativo de patrones cítricos cultivados en condiciones de invernadero bajo dos sistemas de riego Vegetative development of citrus seedlings cultivated at greenhouse conditions and submitted to two irrigations systems

    Directory of Open Access Journals (Sweden)

    Gilmar Schäfer

    2006-08-01

    Full Text Available En el presente estudio se evaluó el desarrollo vegetativo de patrones cítricos cultivados en invernadero bajo dos sistemas de riego. El experimento se realizó en la Estação Experimental Agronômica de la Universidade Federal do Rio Grande do Sul, ubicada en Eldorado do Sul, Rio Grande do Sul, Brasil, entre los meses de septiembre de 2003 y abril de 2004, totalizando 225 días de experimentación. El diseño experimental fue de parcelas subdivididas, en factorial 2 x 3, con 4 repeticiones de 22 contenedores cada. En las parcelas principales se evaluaron los sistemas de riego (microaspersión y capilaridad y en las subparcelas los patrones cítricos Poncirus trifoliata (L. Raf., citrangero 'C37' [P. trifoliata x Citrus sinensis (L. Osb. cv. Pêra] y lima 'Rangpur' (C. limonia Osb.. En condiciones de invernadero los patrones cítricos presentan un desarrollo vegetativo más rápido bajo riego por capilaridad respecto a la microaspersión. Los patrones cítricos evaluados presentan desarrollos vegetativos distintos, donde el citrangero 'C37' supera a los demás.The aim of the present work was to evaluate the vegetative development of citrus rootstock seedlings cultivated under greenhouse conditions with two irrigation systems. The experiment was conducted at the Estação Experimental Agronômica , Universidade Federal do Rio Grande do Sul, located in Eldorado do Sul, Rio Grande do Sul, Brazil, from September 2003 to April 2004, totalizing 225 days of experimentation. The experimental design was a split-plot, in a 2x3 factorial, with 4 replications of 22 pots each. In the main plot the irrigation systems was evaluated (micro sprinkler and capillarity and in the split-plot the citrus rootstocks [Trifoliate orange - Poncirus trifoliata (L. Raf., 'C37' citrange - P. trifoliata x Citrus sinensis (L. Osb. cv. Pêra and 'Rangpur' lime - C. limonia Osb.] were evaluated. The main result showed in conditions of greenhouse citrus rootstock seedlings

  15. The Cultivation of Human Granulosa Cells

    Directory of Open Access Journals (Sweden)

    Lenka Brůčková

    2008-01-01

    Full Text Available The major functions of granulosa cells (GCs include the production of steroids, as well as a myriad of growth factors to interact with the oocyte during its development within the ovarian follicle. Also FSH stimulates GCs to convert androgens (coming from the thecal cells to estradiol by aromatase. However, after ovulation the GCs produce progesterone that may maintain a potential pregnancy. Experiments with human GCs are mainly focused on the purification of GCs from ovarian follicular fluid followed by FACS analysis or short-term cultivation. The aim of our study was to cultivate GCs for a long period, to characterize their morphology and phenotype. Moreover, we have cultivated GCs under gonadotropin stimulation in order to simulate different pathological mechanisms during folliculogenesis (e.g. ovarian hyperstimulation syndrome. GCs were harvested from women undergoing in vitro fertilization. Complex oocyte-cumulus oophorus was dissociated by hyaluronidase. The best condition for transport of GCs was optimized as short transport in follicular fluid at 37 °C. GCs expansion medium consisted of DMEM/F12, 2 % FCS, ascorbic acid, dexamethasone, L-glutamine, gentamycine, penicillin, streptomycin and growth factors (EGF, bFGF. GCs transported in follicular fluid and cultivated in 2 % FCS containing DMEM/F12 medium supplemented with follicular fluid presented increased adhesion, proliferation, viability and decreased doubling time. Cell viability was 92 % and mean cell doubling time was 52 hrs. We have optimized transport and cultivation protocols for long-term cultivation of GCs.

  16. Simultaneous flue gas bioremediation and reduction of microalgal biomass production costs

    Energy Technology Data Exchange (ETDEWEB)

    Douskova, I.; Doucha, J.; Livansky, K.; Umysova, D.; Zachleder, V.; Vitova, M. [Academy of Sciences of the Czech Republic, Trebon (Czech Republic). Laboratory of Cell Cycles of Algae; Machat, J. [Masaryk University, Brno (Czech Republic). Research Centre for Environmental Chemistry and Ecotoxicology; Novak, P. [Termizo Inc., Liberec (Czech Republic)

    2009-02-15

    A flue gas originating from a municipal waste incinerator was used as a source of CO{sub 2} for the cultivation of the microalga Chlorella vulgaris, in order to decrease the biomass production costs and to bioremediate CO{sub 2} simultaneously. The utilization of the flue gas containing 10-13% ({nu}/{nu}) CO2 and 8-10% ({nu}/{nu}) O{sub 2} for the photobioreactor agitation and CO{sub 2} supply was proven to be convenient. The growth rate of algal cultures on the flue gas was even higher when compared with the control culture supplied by a mixture of pure CO{sub 2} and air (11% ({nu}/{nu}) CO{sub 2}). Correspondingly, the CO{sub 2} fixation rate was also higher when using the flue gas (4.4 g CO{sub 2} l{sup -1} 24 h{sup -1}) than using the control gas (3.0 g CO{sub 2} l{sup -1} 24 h{sup -1}). The toxicological analysis of the biomass produced using untreated flue gas showed only a slight excess of mercury while all the other compounds (other heavy metals, polycyclic aromatic hydrocarbons, polychlorinated dibenzodioxins and dibenzofurans, and polychlorinated biphenyls) were below the limits required by the European Union foodstuff legislation. Fortunately, extending the flue gas treatment prior to the cultivation unit by a simple granulated activated carbon column led to an efficient absorption of gaseous mercury and to the algal biomass composition compliant with all the foodstuff legislation requirements. (orig.)

  17. Nannochloropsis oculata D. microalgae growth in a treated effluent from superintensive shrimp cultivation

    Directory of Open Access Journals (Sweden)

    Bruno Menezes Galindro

    2015-07-01

    Full Text Available The use of microalgae biomass in order to obtain lipids is an important alternative to be studied and it has great potential to be applied in order to produce food and biofuel, for instance. However, there are some processes of its production which need further study, such as the cultivation inputs. A possibility for an alternative raw material is the effluent from superintensive shrimp cultivation with bioflocs (BF. Therefore, the objective of this study was to evaluate the productivity and nutrient removal rate of Nannochloropsis oculata cultivation in three systems: (i f/2 - produced integrally with chemical fertilizers, (ii BF - using of 100% of the effluent for superintensive shrimp cultivation with bioflocs and (iii 50/50 – using 50% of shrimp cultivation effluents  and  50% from f/2 system. The microalgae presented greater biomass growth and productitvity in BF system but less lipids and esters accumulation. Concerning nutrient removal, f/2 system showed better performance, which may indicate that the cultivation in BF systems takes longer to reach the stationary growth phase.

  18. Fluoranthene induced changes in photosynthetic pigments, biochemical compounds and enzymatic activities in two microalgal species: Chlorella vulgaris Beijerinck and Desmodesmus subspicatus Chodat

    Directory of Open Access Journals (Sweden)

    Miral Patel

    2014-02-01

    Full Text Available The photosynthetic pigments, biochemical and enzymatic activities in two freshwater microalgal species, Chlorella vulgaris and Desmodesmus subspicatus at different fluoranthene concentrations were compared with the control conditions. During 16-days of incubation period when treated with fluoranthene, both microalgal species exhibited variable amount of photosynthetic pigment, biochemical compounds and enzymatic activities. The addition of fluoranthene at concentrations ranged from 1.5 mg l-1; to 10 mg l-1; to microalgal cultures led to changes in all different metabolites but the patterns varied from species to species. Among the two species tested, pigment, biochemical and enzymatic contents were remarkably declined from 7 % to 95% in C. vulgaris. Moreover, all metabolites in D. subspicatus also diminishing significantly by 3% to 88% of fluoranthene doses (10ppm. These results suggest that fluoranthene-induced changes of pigments, biochemical and enzymatic variations in test microalgae, D. subspicatus and C. vulgaris, might reveal its resistance and ability to metabolize PAHs. At the same time, the PAH impact changes on different metabolic activities were higher at 12 and 16 days than at 4 and 8 days in treated microalgae. DOI: http://dx.doi.org/10.3126/ije.v3i1.9941 International Journal of Environment Vol.3(1 2014: 41-55

  19. Large-scale biodiesel production using flue gas from coal-fired power plants with Nannochloropsis microalgal biomass in open raceway ponds.

    Science.gov (United States)

    Zhu, Baohua; Sun, Faqiang; Yang, Miao; Lu, Lin; Yang, Guanpin; Pan, Kehou

    2014-12-01

    The potential use of microalgal biomass as a biofuel source has raised broad interest. Highly effective and economically feasible biomass generating techniques are essential to realize such potential. Flue gas from coal-fired power plants may serve as an inexpensive carbon source for microalgal culture, and it may also facilitate improvement of the environment once the gas is fixed in biomass. In this study, three strains of the genus Nannochloropsis (4-38, KA2 and 75B1) survived this type of culture and bloomed using flue gas from coal-fired power plants in 8000-L open raceway ponds. Lower temperatures and solar irradiation reduced the biomass yield and lipid productivities of these strains. Strain 4-38 performed better than the other two as it contained higher amounts of triacylglycerols and fatty acids, which are used for biodiesel production. Further optimization of the application of flue gas to microalgal culture should be undertaken. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. An integrated approach for biodiesel and bioethanol production from Scenedesmus bijugatus cultivated in a vertical tubular photobioreactor

    International Nuclear Information System (INIS)

    Ashokkumar, Veeramuthu; Salam, Zainal; Tiwari, O.N.; Chinnasamy, Senthil; Mohammed, Sudheer; Ani, Farid Nasir

    2015-01-01

    Highlights: • Alga Scenedesmus bijugatus was explored for biodiesel and bioethanol production. • Tubular photobioreactor was designed and produced 0.26 g L −1 d −1 of dry biomass. • Sequential stages of transesterification produced 0.21 g biodiesel yield/g dry biomass. • The lipid extracted residues of S. bijugatus produced 0.158 g bioethanol/g dry biomass. - Abstract: Algae are considered promising renewable feedstocks for the production of alternative fuels. In this study, an indigenous strain of Scenedesmus bijugatus found commonly in the fresh water bodies was isolated and evaluated for biofuels production. The alga was successfully mass cultivated in the custom made vertical tubular photobioreactor (250 L capacity) at semi-continuous mode. During the cultivation period, the volumetric biomass and lipid productivity were assessed. The alga S. bijugatus produced 0.26 g L −1 d −1 of dry biomass and 63 mg L −1 d −1 of lipids, respectively. Algal biomass was harvested by a combined harvesting process involving coagulation and flocculation using Iron (III) sulfate and an organic polymer which resulted in 98% harvesting efficiency. Lipid extraction using hexane:diethyl ether (1:2 ratio) resulted in maximum extraction of lipids. This study also examined sequential stages of esterification and transesterification to convert lipids to biodiesel. The maximum biodiesel yield of 0.21 g/g of dry biomass was obtained through the acid base catalytic process. The biodiesel fuel properties were tested and observed that most of the properties complying with ASTM D6751 specifications. The lipid extracted residual biomass recorded a yield of 0.158 g of bioethanol per g. This study confirmed the potential of lipid extracted biomass for the production of bioethanol to improve the economic feasibility of microalgal biorefinery

  1. Technical evaluation of photobioreactors for microalgae cultivation

    Directory of Open Access Journals (Sweden)

    Płaczek Małgorzata

    2017-01-01

    Full Text Available This paper undertakes the description and assessment of various solutions applied for the design of photobioreactors as the type of apparatus, which can provide high output of green algae biomass. The design of such apparatus plays an important role in the context of the concurrent fulfillment of ecological and economic requirements, which are necessary to conduct an efficient and effective technology using cheap and easily accessible resources to produce different goods. Nowadays, algae is seen as one of the most promising sustainable way to produce energy in the future (biofuels, electricity, thermal energy but technologies of biomass production and processing are still under development particularly to increase biomass and energy output. The cultivation costs in closed systems are still high, limiting their commercial applications to high-valued compounds but they can be reduced by efficient bioreactor designs, which are able to achieve high areal biomass productivities. This paper focuses on the advantages and drawbacks associated with the application of the particular types of bioreactors in algae production, description of their operation parameters and area for practical application, pointing of the constructions (tubular, flat panel, bubble column that can contribute to improvement the profitability of large-scale production.

  2. Technical evaluation of photobioreactors for microalgae