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Sample records for microbial biomass sources

  1. 11 Soil Microbial Biomass

    African Journals Online (AJOL)

    186–198. Insam H. (1990). Are the soil microbial biomass and basal respiration governed by the climatic regime? Soil. Biol. Biochem. 22: 525–532. Insam H. D. and Domsch K. H. (1989). Influence of microclimate on soil microbial biomass. Soil Biol. Biochem. 21: 211–21. Jenkinson D. S. (1988). Determination of microbial.

  2. Conditioning biomass for microbial growth

    Science.gov (United States)

    Bodie, Elizabeth A; England, George

    2015-03-31

    The present invention relates to methods for improving the yield of microbial processes that use lignocellulose biomass as a nutrient source. The methods comprise conditioning a composition comprising lignocellulose biomass with an enzyme composition that comprises a phenol oxidizing enzyme. The conditioned composition can support a higher rate of growth of microorganisms in a process. In one embodiment, a laccase composition is used to condition lignocellulose biomass derived from non-woody plants, such as corn and sugar cane. The invention also encompasses methods for culturing microorganisms that are sensitive to inhibitory compounds in lignocellulose biomass. The invention further provides methods of making a product by culturing the production microorganisms in conditioned lignocellulose biomass.

  3. Black Nitrogen as a source for the built-up of microbial biomass in soils

    Science.gov (United States)

    López-Martín, María; Milter, Anja; Knicker, Heike

    2016-04-01

    In areas with frequent wildfires, soil organic nitrogen (SON) is sequestered in pyrogenic organic matter (PyOM) due to heat-induced transformation of proteinaceous compounds into N-heterocycles, i.e. pyrrole, imidazole and indole compounds. These newly formed structures, known as Black Nitrogen (BN), have been assumed to be hardly degradable by microorganisms, thus being efficiently sequestered from the N cycle. On the other hand, a previous study showed that nitrogen of BN can be used by plants for the built-up of their biomass (de la Rosa and Knicker 2011). Thus, BN may play an important role as an N source during the recovery of the forest after a fire event. In order to obtain a more profound understanding of the role of BN within the N cycle in soils, we studied the bioavailability and incorporation of N derived from PyOM into microbial amino acids. For that, pots with soil from a burnt and an unburnt Cambisol located under a Mediterranean forest were covered with different amendments. The toppings were mixtures of unlabeled KNO3 with 15N labeled grass or 15N-labeled PyOM from burned grass and K15NO3 mixed with unlabeled grass material or PyOM. The pots were kept in the greenhouse under controlled conditions for 16 months and were sampled after 0.5, 1, 5, 8 and 16 months. From all samples the amino acids were extracted after hydrolysis (6 M HCl, 22 h, 110 °C) and quantified via gas chromatography mass spectrometry (GC/MS). The fate of 15N was followed by isotopic ratio mass spectrometry (IRMS). The results show that the contribution of extractable amino acids to total soil organic matter was always higher in the unburnt than in the burnt soil. However, with ongoing incubation their amount decreased. Already after 0.5 months, some PyOM-derived 15N was incorporated into the extractable amino acids and the amount increased with experiment time. Since this can only occur after prior microbial degradation of PyOM our results clearly support a lower biochemical

  4. [Effects of adding straw carbon source to root knot nematode diseased soil on soil microbial biomass and protozoa abundance].

    Science.gov (United States)

    Zhang, Si-Hui; Lian, Jian-Hong; Cao, Zhi-Ping; Zhao, Li

    2013-06-01

    A field experiment with successive planting of tomato was conducted to study the effects of adding different amounts of winter wheat straw (2.08 g x kg(-1), 1N; 4.16 g x kg(-1), 2N; and 8.32 g x kg(-1), 4N) to the soil seriously suffered from root knot nematode disease on the soil microbial biomass and protozoa abundance. Adding straw carbon source had significant effects on the contents of soil microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN) and the abundance of soil protozoa, which all decreased in the order of 4N > 2N > 1N > CK. The community structure of soil protozoa also changed significantly under straw addition. In the treatments with straw addition, the average proportion of fagellate, amoeba, and ciliates accounted for 36.0%, 59.5%, and 4.5% of the total protozoa, respectively. Under the same adding amounts of wheat straw, there was an increase in the soil MBC and MBN contents, MBC/MBN ratio, and protozoa abundance with increasing cultivation period.

  5. Phosphorus fractions, microbial biomass and enzyme activities in ...

    African Journals Online (AJOL)

    Potohar, northern Punjab, Pakistan in September, 2008 and analysed for P fractions and microbial parameters including microbial biomass C, microbial biomass N, microbial biomass P, and activities of dehydrogenase and alkaline phosphatase enzymes. The average size of different P fractions (% of total P) in the soils ...

  6. Tillage and manure effect on soil microbial biomass and respiration ...

    African Journals Online (AJOL)

    The objective of this study was to determine the influence of both tillage and liquid pig manure application on soil microbial biomass, enzyme activities and microbial respiration in a meadow soil. The results obtained did not show any significant effect of tillage and manure on microbial biomass carbon (C) and nitrogen (N) ...

  7. The survival strategy of the soil microbial biomass

    Science.gov (United States)

    Brookes, Philip; Kemmitt, Sarah; Dungait, Jennifer; Xu, Jianming

    2014-05-01

    The soil microbial biomass (biomass) is defined as the sum of the masses of all soil microorganisms > 5000 µm3 (e.g. fungi, bacteria, protozoa, yeasts, actinomycetes and algae). Typically comprising about 1 to 3 % of total soil organic matter (SOM), the biomass might be though to live in a highly substrate-rich environment. However, the SOM is, normally, only exceedingly slowly available to the biomass. However the biomass can survive for months or even years on this meagre energy source. Not surprisingly, therefore, the biomass exhibits many features typical of a dormant or resting population. These include a very low rate of basal and specific respiration, a slow rate of cell division (about once every six months on average) and slow turnover rate. These are clearly adaptations to existing in an environment where substrate availability is very low. Yet, paradoxically, the biomass, in soils worldwide, has an adenosine triphosphate (ATP) concentration (around 10 to 12 µmol ATP g-1 biomass C), and an Adenylate Energy Charge (AEC = [(ATP) + (0.5 ADP)]/[(ATP)+(ADP) + (AMP)]) which are typical of microorganisms growing exponentially in a chemostat. This sets us several questions. Firstly, under the condition of extremely limited substrate availability in soil, why does the biomass not mainly exist as spores, becoming active, by increasing both its ATP concentration and AEC, when substrate (plant and animal residues) becomes available? We surmise that a spore strategy may put organisms at a competitive disadvantage, compared to others which are prepared to invest energy, maintaining high ATP and ATP, to take advantage of a 'food event' as soon as it becomes available. Secondly, since SOM is available (although only very slowly) to the biomass, why have some groups not evolved the ability to mineralize it faster, obtain more energy, and so gain a competitive advantage? We believe that the reason why organisms do not use this strategy is, simply, that they cannot. Our

  8. Role of Bioreactors in Microbial Biomass and Energy Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Liang [Chongqing University, Chongqing, China; Zhang, Biao [Chongqing University, Chongqing, China; Zhu, Xun [Chongqing University, Chongqing, China; Chang, Haixing [Chongqing University of Technology; Ou, Shawn [ORNL; Wang, HONG [Chongqing University, Chongqing, China

    2018-04-01

    Bioenergy is the world’s largest contributor to the renewable and sustainable energy sector, and it plays a significant role in various energy industries. A large amount of research has contributed to the rapidly evolving field of bioenergy and one of the most important topics is the use of the bioreactor. Bioreactors play a critical role in the successful development of technologies for microbial biomass cultivation and energy conversion. In this chapter, after a brief introduction to bioreactors (basic concepts, configurations, functions, and influencing factors), the applications of the bioreactor in microbial biomass, microbial biofuel conversion, and microbial electrochemical systems are described. Importantly, the role and significance of the bioreactor in the bioenergy process are discussed to provide a better understanding of the use of bioreactors in managing microbial biomass and energy conversion.

  9. Seasonal variability of microbial biomass phosphorus in urban soils.

    Science.gov (United States)

    Halecki, W; Gąsiorek, M

    2015-01-01

    Urban soils have been formed through human activities. Seasonal evaluation with time-control procedure are essential for plant, and activity of microorganisms. Therefore, these processes are crucial in the urban area due to geochemical changes in the past years. The purpose of this study was to investigate the changes of content of microbial biomass phosphorus (P) in the top layer of soils throughout the season. In this research, the concentration of microbial biomass P ranged from 0.01 to 6.29 mg·kg(-1). We used single-factor repeated-measure analysis of variance to test the effect of season on microbial biomass P content of selected urban soils. We found no statistically significant differences between the concentration of microbial biomass P in the investigated urban and sub-urban soils during the growing season. This analysis explicitly recognised that environmental urban conditions are steady. Specifically, we have studied how vegetation seasonality and ability of microbial biomass P are useful for detecting quality deviations, which affect the equilibrium of urban soil. In conclusion, seasonal variability of the stringency of assurance across the different compounds of soil reveals, as expected, the stable condition of the urban soils. Seasonal responses in microbial biomass P under urban soil use should establish a framework as a reference to the activity of the microorganisms. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Limitations of ATP as a measure of microbial biomass

    African Journals Online (AJOL)

    limits the use of ATP as a measure of microbial biomass. S. AIr. J. Zool. 1982, 17: 93 - 95. Beraming van die totale .... only micro-organisms present in the experimental culture, but these were later succeeded by a large ... a value of 49: I by the last day of the experiment. Estimates of the total living biomass of the heterotro-.

  11. Impact of Wildfire on Microbial Biomass in Critical Zone Observatory

    Science.gov (United States)

    Murphy, M. A.; Fairbanks, D.; Chorover, J.; Gallery, R. E.; Rich, V. I.

    2014-12-01

    The recovery of the critical zone following disturbances such as wildfire is not fully understood. Wildfires have increased in size and intensity in western US forests in recent years and these fires influence soil microbial communities, both in composition and overall biomass. Studies have typically shown a 50% post-fire decline in overall microbial biomass (µg per g soil) that can persist for years. There is however, some variability in the severity of biomass decline, and its relationship with burn severity and landscape position have not yet been studied. Since microbial biomass has a cascade of impacts in soil systems, from helping control the rate and diversity the biogeochemical processes occurring, to promoting soil fertility, to impacting the nature and structure of soil carbon (C), fire's lasting impact on it is one mechanistic determinant of the overall post-fire recovery of impacted ecosystems. Additionally, microbial biomass measurements hold potential for testing and incorporation into land surface models (NoahMP, CLM, etc.) in order to improve estimates of long-term effects of climate change and disturbances such as fire on the C cycle. In order to refine our understanding of the impact of fire on microbial biomass and then relate that to biogeochemical processes and ecosystem recovery, we used chloroform fumigation extraction to quantify total microbial biomass C (Cmic ). One year after the June 2013 Thompson Ridge fire in the Jemez River Basin Critical Zone Observatory, we are measuring the Cmic of 22 sites across a gradient of burn severities and 4 control unburned sites, from six depth intervals at each site (0-2, 2-5, 5-10, 10-20, 20-30, and 30-40 cm). We hypothesize that the decrease in microbial biomass in burned sites relative to control sites will correlate with changes in soil biogeochemistry related to burn severity; and that the extent of the impact on biomass will be inversely related to depth in the soil column. Additionally, as the

  12. Marine Algae: a Source of Biomass for Biotechnological Applications.

    Science.gov (United States)

    Stengel, Dagmar B; Connan, Solène

    2015-01-01

    Biomass derived from marine microalgae and macroalgae is globally recognized as a source of valuable chemical constituents with applications in the agri-horticultural sector (including animal feeds and health and plant stimulants), as human food and food ingredients as well as in the nutraceutical, cosmeceutical, and pharmaceutical industries. Algal biomass supply of sufficient quality and quantity however remains a concern with increasing environmental pressures conflicting with the growing demand. Recent attempts in supplying consistent, safe and environmentally acceptable biomass through cultivation of (macro- and micro-) algal biomass have concentrated on characterizing natural variability in bioactives, and optimizing cultivated materials through strain selection and hybridization, as well as breeding and, more recently, genetic improvements of biomass. Biotechnological tools including metabolomics, transcriptomics, and genomics have recently been extended to algae but, in comparison to microbial or plant biomass, still remain underdeveloped. Current progress in algal biotechnology is driven by an increased demand for new sources of biomass due to several global challenges, new discoveries and technologies available as well as an increased global awareness of the many applications of algae. Algal diversity and complexity provides significant potential provided that shortages in suitable and safe biomass can be met, and consumer demands are matched by commercial investment in product development.

  13. Soil microbial biomass in an agroforestry system of Northeast Brazil

    Directory of Open Access Journals (Sweden)

    Rosane C. Rodrigues

    2015-01-01

    Full Text Available Agroforestry systems (AFS are considered alternative land use options to help prevent soil degradation and improve soil microbial biomass and organic C status. However, it is unclear how different densities of babassu palm [Attalea speciosa (syn. Orbignya phalerata], which is an important tree in Northeast Brazil, affect the soil microbial biomass. We investigated the soil microbial biomass C and activity under AFS with different densities of babassu palm associated with Brachiaria brizantha grass. Soil microbial biomass C (MBC, soil microbial biomass N (MBN, MBC:total organic C ratio, fluorescein diacetate hydrolysis and dehydrogenase activity showed highest values in plots with high density of babassu palm. On the other hand, the respiratory quotient (qCO2 was significantly greater in plots without babassu palm. Brachiaria brizantha in monoculture may promote C losses from the soil, but AFS with high density of babassu palm may increase the potential of soils to accumulate C.Keywords: Enzyme activity, tropical soil, babassu palm, silvopastoral system, soil quality.DOI: 10.17138/TGFT(341-48

  14. Measurement and characteristics of microbial biomass in forest soils

    International Nuclear Information System (INIS)

    Vance, E.D.

    1986-01-01

    The soil microbial biomass is the primary agent responsible for the breakdown and mineralization of soil organic matter and plays a major role in regulating nutrient availability to plants. In this study, methods for measuring biomass in soil were compared and tested in forest soils ranging in pH from 3.2 to 7.2. A good relationship between biomass C measured using the chloroform fumigation-incubation method and soil ATP or microbial biomass C by direct microscopy was found in soils at or above pH 4.2. The fumigation-incubation method consistently underestimated biomass C in soils below pH 4.2, however. Hypotheses for the breakdown of the fumigation-incubation method in strongly acid soils were tested by using an alterative fumigant, measuring the proportion of added 14 C labelled fungi and bacteria decomposed in fumigated soils (k/sub C/), and by studying the effect of large, non-fumigated soil inocula on the flush of respiration following fumigation. These studies indicated that the failure of the method in strongly acid soils was due to inhibited decomposition of non-microbial soil organic matter by the microbial recolonizing population following fumigation. A modified method for measuring biomass C by fumigation-incubation in acid soils is proposed

  15. BIOMASS AND MICROBIAL ACTIVITY UNDER DIFFERENT FOREST COVERS

    Directory of Open Access Journals (Sweden)

    Rafael Malfitano Braga

    2016-06-01

    Full Text Available This study evaluated the soil fertility, biomass and microbial activity of the soil under forest cover of Eucalyptus grandis, Eucalyptus pilularis, Eucalyptus cloeziana and Corymbia maculata; Pinus Caribbean var. hondurensis, 40 years old, and a fragment of Semideciduous Forest, located on the campus of the Federal University of Lavras. In soil samples collected in the 0-5 cm layer were determined fertility parameters, basal respiration and microbial biomass carbon. The results showed that for the species E. grandis and E. cloeziana the carbon of biomass microbial content was higher than for any other ecosystem evaluated, and equal to those observed under native forest. In contrast, the ground under Pinus had the lowest microbiological indexes. Under C. maculata and E. pilularis the contents were intermediate for this parameter. The basal respiration of all ecosystems was equal. The fertility level was very low in all types of evaluated vegetation.

  16. Manufacture of Prebiotics from Biomass Sources

    Science.gov (United States)

    Gullón, Patricia; Gullón, Beatriz; Moure, Andrés; Alonso, José Luis; Domínguez, Herminia; Parajó, Juan Carlos

    Biomass from plant material is the most abundant and widespread renewable raw material for sustainable development, and can be employed as a source of polymeric and oligomeric carbohydrates. When ingested as a part of the diet, some biomass polysaccharides and/or their oligomeric hydrolysis products are selectively fermented in the colon, causing prebiotic effects.

  17. The contribution of microbial biomass to the adsorption of radioiodide in soils

    International Nuclear Information System (INIS)

    Bors, J.; Martens, R.

    1992-01-01

    The contribution of soil microbial biomass to the sorption and migration of radiodide in soil has been investigated. In two arable soils, a chernozem and a podzol, the numbers of microorganisms were either reduced by biocidal treatment or increased by addition of nutrient sources. Radioiodide ( 125 I - ) adsorption by the pretreated soils was measured, relative to untreated soil samples, in aqueous suspensions containing iodide by estimating the distribution coefficient (K d ) after eight days of incubation. A reduction of biomass to about 10% of its original level drastically decreased adsorption. Elevated levels of microbial biomass (up to 126%) increased adsorption but the increase was not always correlated with biomass level. A closer correlation between soil biomass and adsorption was observed when the concentration of radioiodide in the suspension was increased by several orders of magnitude. Conditions such as anarobiosis and elevated temperatures which are known to influence the activity and survival of microorganisms also exerted an effect on radioiodide sorption. In accordance with the relationship described here between radioiodide adsorption and microbial biomass, migration in water saturated soil columns was influenced by the quantity of microorganisms present. However, high biomass contents obviously caused anaerobic conditions in the system, leading to increased leaching of radioiodide. (author)

  18. The contribution of microbial biomass to the adsorption of radioiodide in soils

    Energy Technology Data Exchange (ETDEWEB)

    Bors, J. (Niedersaechsisches Inst. fuer Radiooekologie, Hannover (Germany)); Martens, R. (Bundesforschungsanstalt fuer Landwirtschaft, Braunschweig (Germany). Inst. fuer Biochemie des Bodens)

    1992-01-01

    The contribution of soil microbial biomass to the sorption and migration of radiodide in soil has been investigated. In two arable soils, a chernozem and a podzol, the numbers of microorganisms were either reduced by biocidal treatment or increased by addition of nutrient sources. Radioiodide ({sup 125}I{sup -}) adsorption by the pretreated soils was measured, relative to untreated soil samples, in aqueous suspensions containing iodide by estimating the distribution coefficient (K{sub d}) after eight days of incubation. A reduction of biomass to about 10% of its original level drastically decreased adsorption. Elevated levels of microbial biomass (up to 126%) increased adsorption but the increase was not always correlated with biomass level. A closer correlation between soil biomass and adsorption was observed when the concentration of radioiodide in the suspension was increased by several orders of magnitude. Conditions such as anarobiosis and elevated temperatures which are known to influence the activity and survival of microorganisms also exerted an effect on radioiodide sorption. In accordance with the relationship described here between radioiodide adsorption and microbial biomass, migration in water saturated soil columns was influenced by the quantity of microorganisms present. However, high biomass contents obviously caused anaerobic conditions in the system, leading to increased leaching of radioiodide. (author).

  19. Effects of uranium on soil microbial biomass carbon, enzymes, plant biomass and microbial diversity in yellow soils

    International Nuclear Information System (INIS)

    Yan, X.; Zhang, Y.; Luo, X.; Yu, L.

    2016-01-01

    We conducted an experiment to investigate the effects of uranium (U) on soil microbial biomass carbon (MBC), enzymes, plant biomass and microbial diversity in yellow soils under three concentrations: 0 mg kg"-"1 (T1, control), 30 mg kg"-"1 (T2) and 60 mg kg"-"1 (T3). Under each treatment, elevated U did not reduce soil MBC or plant biomass, but inhibited the activity of the soil enzymes urease (UR), dehydrogenase (DH) and phosphatase (PHO). The microbial diversity was different, with eight dominant phyla in T1 and six in T2 and T3. Furthermore, Proteobacteria and material X were both detected in each treatment site (T1, T2 and T3). Pseudomonas sp. was the dominant strain, followed by Acidiphilium sp. This initial study provided valuable data for further research toward a better understanding of U contamination in yellow soils in China. (authors)

  20. Measures of Microbial Biomass for Soil Carbon Decomposition Models

    Science.gov (United States)

    Mayes, M. A.; Dabbs, J.; Steinweg, J. M.; Schadt, C. W.; Kluber, L. A.; Wang, G.; Jagadamma, S.

    2014-12-01

    Explicit parameterization of the decomposition of plant inputs and soil organic matter by microbes is becoming more widely accepted in models of various complexity, ranging from detailed process models to global-scale earth system models. While there are multiple ways to measure microbial biomass, chloroform fumigation-extraction (CFE) is commonly used to parameterize models.. However CFE is labor- and time-intensive, requires toxic chemicals, and it provides no specific information about the composition or function of the microbial community. We investigated correlations between measures of: CFE; DNA extraction yield; QPCR base-gene copy numbers for Bacteria, Fungi and Archaea; phospholipid fatty acid analysis; and direct cell counts to determine the potential for use as proxies for microbial biomass. As our ultimate goal is to develop a reliable, more informative, and faster methods to predict microbial biomass for use in models, we also examined basic soil physiochemical characteristics including texture, organic matter content, pH, etc. to identify multi-factor predictive correlations with one or more measures of the microbial community. Our work will have application to both microbial ecology studies and the next generation of process and earth system models.

  1. Quantitative analysis of microbial biomass yield in aerobic bioreactor.

    Science.gov (United States)

    Watanabe, Osamu; Isoda, Satoru

    2013-12-01

    We have studied the integrated model of reaction rate equations with thermal energy balance in aerobic bioreactor for food waste decomposition and showed that the integrated model has the capability both of monitoring microbial activity in real time and of analyzing biodegradation kinetics and thermal-hydrodynamic properties. On the other hand, concerning microbial metabolism, it was known that balancing catabolic reactions with anabolic reactions in terms of energy and electron flow provides stoichiometric metabolic reactions and enables the estimation of microbial biomass yield (stoichiometric reaction model). We have studied a method for estimating real-time microbial biomass yield in the bioreactor during food waste decomposition by combining the integrated model with the stoichiometric reaction model. As a result, it was found that the time course of microbial biomass yield in the bioreactor during decomposition can be evaluated using the operational data of the bioreactor (weight of input food waste and bed temperature) by the combined model. The combined model can be applied to manage a food waste decomposition not only for controlling system operation to keep microbial activity stable, but also for producing value-added products such as compost on optimum condition. Copyright © 2013 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

  2. Biomass as an alternative energy source

    Energy Technology Data Exchange (ETDEWEB)

    De Bruyn, M.; Naveau, H.; Declerck, C.; Vanacker, L.; Mahy, D.; Schepens, G.

    The object of this paper is to evaluate the possible production and utilization of biomass as an energy source in Belgium. Four conversion methods are considered - methanation, fermentation, incineration and gasification - from a technological and economic viewpoint.

  3. Importance of biomass energy sources for Turkey

    International Nuclear Information System (INIS)

    Demirbas, Ayhan

    2008-01-01

    Various agricultural residues such as grain dust, crop residues and fruit tree residues are available in Turkey as the sources of biomass energy. Among the biomass energy sources, fuelwood seems to be one of the most interesting because its share of the total energy production of Turkey is high at 21% and the techniques for converting it to useful energy are not necessarily sophisticated. Selection of a particular biomass for energy requirements is influenced by its availability, source and transportation cost, competing uses and prevalent fossil fuel prices. Utilization of biomass is a very attractive energy resource, particularly for developing countries since biomass uses local feedstocks and labor. Like many developing countries, Turkey relies on biomass to provide much of its energy requirement. More efficient use of biomass in producing energy, both electrical and thermal, may allow Turkey to reduce petroleum imports, thus affecting its balance of payments dramatically. Turkey has always been one of the major agricultural countries in the world. The importance of agriculture is increasing due to biomass energy being one of the major resources in Turkey. Biomass waste materials can be used in Turkey to provide centralized, medium- and large-scale production of process heat for electricity production. Turkey's first biomass power project is under development in Adana province, at an installed capacity of 45 MW. Two others, at a total capacity of 30 MW, are at the feasibility study stage in Mersin and Tarsus provinces. Electricity production from biomass has been found to be a promising method in the nearest future in Turkey

  4. Membrane bioreactor biomass characteristics and microbial yield at ...

    African Journals Online (AJOL)

    In this study, a laboratory-scale MBR and SBR were operated in parallel and at very low MCRTs (3 d, 2 d, 1 d and 0.5 d) to assess the relative bioreactor performance, biomass characteristics, and microbial yield. This study confirmed that the MBR maintains higher solids levels and better overall effluent quality than ...

  5. Metal impacts on microbial biomass in the anoxic sediments of a contaminated lake

    Energy Technology Data Exchange (ETDEWEB)

    Gough, Heidi L.; Dahl, Amy L.; Nolan, Melissa A.; Gaillard, Jean-Francois; Stahl, David A.

    2008-04-26

    Little is known about the long-term impacts of metal contamination on the microbiota of anoxic lake sediments. In this study, we examined microbial biomass and metals (arsenic, cadmium, chromium, copper, iron, lead, manganese, and zinc) in the sediments of Lake DePue, a backwater lake located near a former zinc smelter. Sediment core samples were examined using two independent measures for microbial biomass (total microscopic counts and total phospholipid-phosphate concentrations), and for various fractions of each metal (pore water extracts, sequential extractions, and total extracts of all studied metals and zinc speciation by X-ray absorption fine structure (XAFS). Zinc concentrations were up to 1000 times higher than reported for sediments in the adjacent Illinois River, and ranged from 21,400 mg/kg near the source to 1,680 mg/kg near the river. However, solid metal fractions were not well correlated with pore water concentrations, and were not good predictors of biomass concentrations. Instead, biomass, which varied among sites by as much as two-times, was inversely correlated with concentrations of pore water zinc and arsenic as established by multiple linear regression. Monitoring of other parameters known to naturally influence biomass in sediments (e.g., organic carbon concentrations, nitrogen concentrations, pH, sediment texture, and macrophytes) revealed no differences that could explain observed biomass trends. This study provides strong support for control of microbial abundance by pore water metal concentrations in contaminated freshwater sediments.

  6. Microbial respiration per unit microbial biomass increases with carbon-to-nutrient ratios in soils

    Science.gov (United States)

    Spohn, Marie; Chodak, Marcin

    2015-04-01

    The ratio of carbon-to-nutrient in forest floors is usually much higher than the ratio of carbon-to-nutrient that soil microorganisms require for their nutrition. In order to understand how this mismatch affects carbon cycling, the respiration rate per unit soil microbial biomass carbon - the metabolic quotient (qCO2) - was studied. This was done in a field study (Spohn and Chodak, 2015) and in a meta-analysis of published data (Spohn, 2014). Cores of beech, spruce, and mixed spruce-beech forest soils were cut into slices of 1 cm from the top of the litter layer down to 5 cm in the mineral soil, and the relationship between the qCO2 and the soil carbon-to-nitrogen (C:N) and the soil carbon-to-phosphorus (C:P) ratio was analyzed. We found that the qCO2 was positively correlated with soil C:N ratio in spruce soils (R = 0.72), and with the soil C:P ratio in beech (R = 0.93), spruce (R = 0.80) and mixed forest soils (R = 0.96). We also observed a close correlation between the qCO2 and the soil C concentration in all three forest types. Yet, the qCO2 decreased less with depth than the C concentration in all three forest types, suggesting that the change in qCO2 is not only controlled by the soil C concentration. We conclude that microorganisms increase their respiration rate per unit biomass with increasing soil C:P ratio and C concentration, which adjusts the substrate to their nutritional demands in terms of stoichiometry. In an analysis of literature data, I tested the effect of the C:N ratio of soil litter layers on microbial respiration in absolute terms and per unit microbial biomass C. For this purpose, a global dataset on the microbial respiration rate per unit microbial biomass C - termed the metabolic quotient (qCO2) - was compiled form literature data. It was found that the qCO2 in the soil litter layers was positively correlated with the litter C:N ratio and negatively related with the litter nitrogen (N) concentration. The positive relation between the qCO2

  7. Microbial plankton communities in the coastal southeastern Black Sea: biomass, composition and trophic interactions

    Directory of Open Access Journals (Sweden)

    Ulgen Aytan

    2018-04-01

    Full Text Available Summary: We investigated biomass and composition of the pico-, nano- and microplankton communities in a coastal station of the southeastern Black Sea during 2011. We also examined trophic interactions within these communities from size-fractionated dilution experiments in February, June and December. Autotrophic and heterotrophic biomasses showed similar seasonal trends, with a peak in June, but heterotrophs dominated throughout the year. Autotrophic biomass was mainly comprised by nanoflagellates and diatoms in the first half of the year, and by dinoflagellates and Synechococcus spp. in the second half. Heterotrophic biomass was mostly dominated by heterotrophic bacteria, followed by nanoflagellates and microzooplankton. Dilution experiments suggest that nano- and microzooplankton were significant consumers of autotrophs and heterotrophic bacteria. More than 100% of bacterial production was consumed by grazers in all experiments, while 46%, 21% and 30% of daily primary production were consumed in February, June and December, respectively. In February, autotrophs were the main carbon source, but in December, it was heterotrophic bacteria. An intermediate situation was observed in June, with similar carbon flows from autotrophs and heterotrophic bacteria. Size-fraction dilution experiments suggested that heterotrophic nanoflagellates are an important link between the high heterotrophic bacterial biomass and microzooplankton. In summary, these results indicate that nano- and microzooplankton were responsible for comprising a significant fraction of total microbial plankton biomass, standing stocks, growth and grazing processes. This suggests that in 2011, the microbial food web was an important compartment of the planktonic food web in the coastal southeastern Black Sea. Keywords: Phytoplankton, Microzooplankton, Carbon biomass, Microbial food web, Grazing, Black Sea

  8. Forest biomass as an energy source

    Science.gov (United States)

    P.E. Laks; R.W. Hemingway; A. Conner

    1979-01-01

    The Task Force on Forest Biomass as an Energy Source was chartered by the Society of American Foresters on September 26, 1977, and took its present form following an amendment to the charter on October 5, 1977. It built upon the findings of two previous task forces, the Task Force on Energy and Forest Resources and the Task Force for Evaluation of the CORRIM Report (...

  9. Renewable biofuels bioconversion of lignocellulosic biomass by microbial community

    CERN Document Server

    Rana, Vandana

    2017-01-01

    This book offers a complete introduction for novices to understand key concepts of biocatalysis and how to produce in-house enzymes that can be used for low-cost biofuels production. The authors discuss the challenges involved in the commercialization of the biofuel industry, given the expense of commercial enzymes used for lignocellulose conversion. They describe the limitations in the process, such as complexity of lignocellulose structure, different microbial communities’ actions and interactions for degrading the recalcitrant structure of lignocellulosic materials, hydrolysis mechanism and potential for bio refinery. Readers will gain understanding of the key concepts of microbial catalysis of lignocellulosic biomass, process complexities and selection of microbes for catalysis or genetic engineering to improve the production of bioethanol or biofuel.

  10. A meta-analysis of soil microbial biomass responses to forest disturbances

    Directory of Open Access Journals (Sweden)

    Sandra Robin Holden

    2013-06-01

    Full Text Available Climate warming is likely to increase the frequency and severity of forest disturbances, with uncertain consequences for soil microbial communities and their contribution to ecosystem C dynamics. To address this uncertainty, we conducted a meta-analysis of 139 published soil microbial responses to forest disturbances. These disturbances included abiotic (fire, harvesting, storm and biotic (insect, pathogen disturbances. We hypothesized that soil microbial biomass would decline following forest disturbances, but that abiotic disturbances would elicit greater reductions in microbial biomass than biotic disturbances. In support of this hypothesis, across all published studies, disturbances reduced soil microbial biomass by an average of 29.4%. However, microbial responses differed between abiotic and biotic disturbances. Microbial responses were significantly negative following fires, harvest, and storms (48.7%, 19.1%, and 41.7% reductions in microbial biomass, respectively. In contrast, changes in soil microbial biomass following insect infestation and pathogen-induced tree mortality were non-significant, although biotic disturbances were poorly represented in the literature. When measured separately, fungal and bacterial responses to disturbances mirrored the response of the microbial community as a whole. Changes in microbial abundance following disturbance were significantly positively correlated with changes in microbial respiration. We propose that the differential effect of abiotic and biotic disturbances on microbial biomass may be attributable to differences in soil disruption and organic C removal from forests among disturbance types. Altogether, these results suggest that abiotic forest disturbances may significantly decrease soil microbial abundance, with corresponding consequences for microbial respiration. Further studies are needed on the effect of biotic disturbances on forest soil microbial communities and soil C dynamics.

  11. Effects of lead and cadmium nitrate on biomass and substrate utilization pattern of soil microbial communities.

    Science.gov (United States)

    Muhammad, Akmal; Xu, Jianming; Li, Zhaojun; Wang, Haizhen; Yao, Huaiying

    2005-07-01

    A study was conducted to evaluate the effects of different concentrations of lead (Pb) and cadmium (Cd) applied as their nitrates on soil microbial biomass carbon (C(mic)) and nitrogen (N(mic)), and substrate utilization pattern of soil microbial communities. The C(mic) and N(mic) contents were determined at 0, 14, 28, 42 and 56 days after heavy metal application (DAA). The results showed a significant decline in the C(mic) for all Pb and Cd amended soils from the start to 28 DAA. From 28 to 56 DAA, C(mic) contents changed non-significantly for all other treatments except for 600 mgkg(-1) Pb and 100 mgkg(-1) Cd in which it declined significantly from 42 to 56 DAA. The N(mic) contents also decreased significantly from start to 28 DAA for all other Pb and Cd treatments except for 200 mgkg(-1) Pb which did not show significant difference from the control. Control and 200 mgkg(-1) Pb had significantly lower soil microbial biomass C:N ratio as compared with other Pb treatments from 14 to 42 DAA, however at 56 DAA, only 1000 mgkg(-1) Pb showed significantly higher C:N ratio compared with other treatments. No significant difference in C:N ratio for all Cd treated soils was seen from start to 28 DAA, however from 42 to 56 DAA, 100 mgkg(-1) Pb showed significantly higher C:N ratio compared with other treatments. On 56 DAA, substrate utilization pattern of soil microbial communities was determined by inoculating Biolog ECO plates. The results indicated that Pb and Cd addition inhibited the functional activity of soil microbial communities as indicated by the intensity of average well color development (AWCD) during 168 h of incubation. Multivariate analysis of sole carbon source utilization pattern demonstrated that higher levels of heavy metal application had significantly affected soil microbial community structure.

  12. [Applications of GIS in biomass energy source research].

    Science.gov (United States)

    Su, Xian-Ming; Wang, Wu-Kui; Li, Yi-Wei; Sun, Wen-Xiang; Shi, Hai; Zhang, Da-Hong

    2010-03-01

    Biomass resources have the characteristics of widespread and dispersed distribution, which have close relations to the environment, climate, soil, and land use, etc. Geographic information system (GIS) has the functions of spatial analysis and the flexibility of integrating with other application models and algorithms, being of predominance to the biomass energy source research. This paper summarized the researches on the GIS applications in biomass energy source research, with the focus in the feasibility study of bioenergy development, assessment of biomass resources amount and distribution, layout of biomass exploitation and utilization, evaluation of gaseous emission from biomass burning, and biomass energy information system. Three perspectives of GIS applications in biomass energy source research were proposed, i. e., to enrich the data source, to improve the capacity on data processing and decision-support, and to generate the online proposal.

  13. Soil plus root respiration and microbial biomass following water, nitrogen, and phosphorus application at a high arctic semi desert

    DEFF Research Database (Denmark)

    Illeris, Lotte; Michelsen, Anders; Jonasson, Sven Evert

    2003-01-01

    CO2 emmision, Decomposition, Microbial biomass carbon, Soil organic matter, Tundra, Water and nutrient limitation......CO2 emmision, Decomposition, Microbial biomass carbon, Soil organic matter, Tundra, Water and nutrient limitation...

  14. Microbial degradation of coconut coir dust for biomass production

    Energy Technology Data Exchange (ETDEWEB)

    Uyenco, F.R.; Ochoa, J.A.K.

    Several species of white-rot fungi were studied for its ability to degrade the lignocellulose components of coir dust at optimum conditions. The most effective fungi was Phanerochaeta chrysosporium UPCC 4003. This organism degraded the lignocellulose complex of coir dust at a rate of about 25 percent in 4 weeks. The degradation process was carried on with minimal nitrogen concentration, coconut water supplementation and moisture levels between 85-90 percent. Shake flask cultures of the degraded coir dust using cellulolytic fungi were not effective. In fermentor cultures with Chaetomium cellulolyticum UPCC 3934, supplemented coir dust was converted into a microbial biomass product (MBP) with 15.58 percent lignin, 19.20 percent cellulose and 18.87 percent protein. More work is being done on the utilization of coir dust on a low technology.

  15. [Microbial biomass and growth kinetics of microorganisms in chernozem soils under different farm land use modes].

    Science.gov (United States)

    Blagodatskiĭ, S A; Bogomolova, I N; Blagodatskaia, E V

    2008-01-01

    The carbon content of microbial biomass and the kinetic characteristics of microbial respiration response to substrate introduction have been estimated for chernozem soils of different farm lands: arable lands used for 10, 46, and 76 years, mowed fallow land, non-mowed fallow land, and woodland. Microbial biomass and the content of microbial carbon in humus (Cmic/Corg) decreased in the following order: soils under forest cenoses-mowed fallow land-10-year arable land-46- and 75-year arable land. The amount of microbial carbon in the long-plowed horizon was 40% of its content in the upper horizon of non-mowed fallow land. Arable soils were characterized by a lower metabolic diversity of microbial community and by the highest portion of microorganisms able to grow directly on glucose introduced into soil. The effects of different scenarios of carbon sequestration in soil on the reserves and activity of microbial biomass are discussed.

  16. Mineralogical controls on microbial biomass accumulation on two tropical soils

    Science.gov (United States)

    Block, K. A.; Pena, S. A.; Katz, A.; Gottlieb, P.; Volta, A.

    2017-12-01

    The characteristics of soil organic matter (SOM) generated by microbes and associated with minerals are not well defined. This information is critical to reducing uncertainty in climate models related to C cycling and ecosystem feedbacks. The resistance to degradation of mineral-associated SOM is influenced by aggregate structure, mineral chemistry and microbial community. In this work we examine the influence of mineral composition, including amorphous coatings on the biomass yield and aggregate structure through thermogravimetric analysis, X-ray diffraction and electron microscopy. Two soil organisms, Pseudomonas phaseolicola, and Streptomyces griseosporus, were each incubated over a 72-hour period in minimal media with the cultured under the same conditions. In all samples, approximately half of the sample mass loss occurred between 175 ºC - 375 ºC, which we attribute to biomolecules accumulated on the mineral surfaces. We observed a slightly larger mass loss in the Inceptisol than in the Oxisol, most of which corresponded to compounds that underwent pyrolysis at 300 ºC. HRTEM micrographs and TEM-EDS image maps showing the spatial relationship of microbial necromass to soil minerals will be reported.

  17. Does microbial biomass affect pelagic ecosystem efficiency? An experimental study.

    Science.gov (United States)

    Wehr, J D; Le, J; Campbell, L

    1994-01-01

    Bacteria and other microorganisms in the pelagic zone participate in the recycling of organic matter and nutrients within the water column. The microbial loop is thought to enhance ecosystem efficiency through rapid recycling and reduced sinking rates, thus reducing the loss of nutrients contained in organisms remaining within the photic zone. We conducted experiments with lake communities in 5400-liter mesocosms, and measured the flux of materials and nutrients out of the water column. A factorial design manipulated 8 nutrient treatments: 4 phosphorus levels × 2 nitrogen levels. Total sedimentation rates were greatest in high-N mesocosms; within N-surplus communities, [Symbol: see text]1 µM P resulted in 50% increase in total particulate losses. P additions without added N had small effects on nutrient losses from the photic zone; +2 µM P tanks received 334 mg P per tank, yet after 14 days lost only 69 mg more particulate-P than did control communities. Nutrient treatments resulted in marked differences in phytoplankton biomass (twofold N effect, fivefold P effect in +N mesocosms only), bacterioplankton densities (twofold N-effect, twofold P effects in -N and +N mesocosms), and the relative importance of autotrophic picoplankton (maximum in high NY mesocosms). Multiple regression analysis found that of 8 plankton and water chemistry variables, the ratio of autotrophic picoplankton to total phytoplankton (measured as chlorophyll α) explained the largest portion of the total variation in sedimentation loss rates (65% of P-flux, 57% of N-flux, 26% of total flux). In each case, systems with greater relative importance of autotrophic picoplankton had significantly reduced loss rates. In contrast, greater numbers of planktonic bacteria were associated with increased sedimentation rates and lower system efficiency. We suggest that different microbial components may have contrasting effects on the presumed enhanced efficiency provided by the microbial loop.

  18. Hydropower and biomass as renewable energy sources in Turkey

    International Nuclear Information System (INIS)

    Kaygusuz, K.

    2001-01-01

    When talking about renewable energy sources today, the most important and economical energy sources for Turkey are hydropower and biomass.The present study gives a review of production, consumption, and economics of hydropower and biomass as renewable energy sources in Turkey. Turkey has a total gross hydropower potential of 433 GW, but only 125 GW of the total hydroelectric potential of Turkey can be economically used. By the commissioning of new hydropower plants, which are under construction, 36% of the economically usable potential of the country could be tapped. On the other hand, biomass (wood and wastes) energy is the second most important renewable energy source for Turkey. However, the biomass energy sources of Turkey are limited. In 1998, the biomass share of the total energy consumption of the country is 10%. In this study, the potential of important biomass energy sources and animal solid wastes of the country were determined. The effects of hydropower and biomass usage on the environment were also discussed. Considering total cereal products and fatty seed plants, approximately 50-60 million tons per year of biomass and 8-10 million tons of solid matter animal waste are produced, and 70% of total biomass is seen as being usable for energy. Some useful suggestions and recommendations are also presented. The present study shows that there is an important potential for hydropower and biomass energy sources in Turkey. (author)

  19. 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

  20. Non-microbial sources of microbial volatile organic compounds.

    Science.gov (United States)

    Choi, Hyunok; Schmidbauer, Norbert; Bornehag, Carl-Gustaf

    2016-07-01

    The question regarding the true sources of the purported microbial volatile organic compounds (MVOCs) remains unanswered. To identify microbial, as well as non-microbial sources of 28 compounds, which are commonly accepted as microbial VOCs (i.e. primary outcome of interest is Σ 28 VOCs). In a cross-sectional investigation of 390 homes, six building inspectors assessed water/mold damage, took air and dust samples, and measured environmental conditions (i.e., absolute humidity (AH, g/m(3)), temperature (°C), ventilation rate (ACH)). The air sample was analyzed for volatile organic compounds (μg/m(3)) and; dust samples were analyzed for total viable fungal concentration (CFU/g) and six phthalates (mg/g dust). Four benchmark variables of the underlying sources were defined as highest quartile categories of: 1) the total concentration of 17 propylene glycol and propylene glycol ethers (Σ17 PGEs) in the air sample; 2) 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate (TMPD-MIB) in the air sample; 3) semi-quantitative mold index; and 4) total fungal load (CFU/g). Within severely damp homes, co-occurrence of the highest quartile concentration of either Σ17 PGEs or TMPD-MIB were respectively associated with a significantly higher median concentration of Σ 28 VOCs (8.05 and 13.38μg/m(3), respectively) compared to the reference homes (4.30 and 4.86μg/m(3), respectively, both Ps ≤0.002). Furthermore, the homes within the highest quartile range for Σ fungal load as well as AH were associated with a significantly increased median Σ 28 VOCs compared to the reference group (8.74 vs. 4.32μg/m(3), P=0.001). Within the final model of multiple indoor sources on Σ 28 VOCs, one natural log-unit increase in summed concentration of Σ17 PGEs, plus TMPD-MIB (Σ 17 PGEs + TMPD-MIB) was associated with 1.8-times (95% CI, 1.3-2.5), greater likelihood of having a highest quartile of Σ 28 VOCs, after adjusting for absolute humidity, history of repainting at least one room

  1. Colonization Habitat Controls Biomass, Composition, and Metabolic Activity of Attached Microbial Communities in the Columbia River Hyporheic Corridor

    Energy Technology Data Exchange (ETDEWEB)

    Stern, Noah; Ginder-Vogel, Matthew; Stegen, James C.; Arntzen, Evan; Kennedy, David W.; Larget, Bret R.; Roden, Eric E.; Kostka, Joel E.

    2017-06-09

    Hydrologic exchange plays a critical role in biogeochemical cycling within the hyporheic zone (the interface between river water and groundwater) of riverine ecosystems. Such exchange may set limits on the rates of microbial metabolism and impose deterministic selection on microbial communities that adapt to dynamically changing dissolved organic carbon (DOC) sources. This study examined the response of attached microbial communities (in situcolonized sand packs) from groundwater, hyporheic, and riverbed habitats within the Columbia River hyporheic corridor to “cross-feeding” with either groundwater, river water, or DOC-free artificial fluids. Our working hypothesis was that deterministic selection duringin situcolonization would dictate the response to cross-feeding, with communities displaying maximal biomass and respiration when supplied with their native fluid source. In contrast to expectations, the major observation was that the riverbed colonized sand had much higher biomass and respiratory activity, as well as a distinct community structure, compared with those of the hyporheic and groundwater colonized sands. 16S rRNA gene amplicon sequencing revealed a much higher proportion of certain heterotrophic taxa as well as significant numbers of eukaryotic algal chloroplasts in the riverbed colonized sand. Significant quantities of DOC were released from riverbed sediment and colonized sand, and separate experiments showed that the released DOC stimulated respiration in the groundwater and piezometer colonized sand. These results suggest that the accumulation and degradation of labile particulate organic carbon (POC) within the riverbed are likely to release DOC, which may enter the hyporheic corridor during hydrologic exchange, thereby stimulating microbial activity and imposing deterministic selective pressure on the microbial community composition.

    IMPORTANCEThe influence of river water

  2. Microbial conversion of biomass into bio-based polymers.

    Science.gov (United States)

    Kawaguchi, Hideo; Ogino, Chiaki; Kondo, Akihiko

    2017-12-01

    The worldwide market for plastics is rapidly growing, and plastics polymers are typically produced from petroleum-based chemicals. The overdependence on petroleum-based chemicals for polymer production raises economic and environmental sustainability concerns. Recent progress in metabolic engineering has expanded fermentation products from existing aliphatic acids or alcohols to include aromatic compounds. This diversity provides an opportunity to expand the development and industrial uses of high-performance bio-based polymers. However, most of the biomonomers are produced from edible sugars or starches that compete directly with food and feed uses. The present review focuses on recent progress in the microbial conversion of biomass into bio-based polymers, in which fermentative products from renewable feedstocks serve as biomonomers for the synthesis of bio-based polymers. In particular, the production of biomonomers from inedible lignocellulosic feedstocks by metabolically engineered microorganisms and the synthesis of bio-based engineered plastics from the biological resources are discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. A Compilation of Global Soil Microbial Biomass Carbon, Nitrogen, and Phosphorus Data

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides the concentrations of soil microbial biomass carbon (C), nitrogen (N) and phosphorus (P), soil organic carbon, total nitrogen, and total...

  4. Bioaugmentation for Electricity Generation from Corn Stover Biomass Using Microbial Fuel Cells

    KAUST Repository

    Wang, Xin; Feng, Yujie; Wang, Heming; Qu, Youpeng; Yu, Yanling; Ren, Nanqi; Li, Nan; Wang, Elle; Lee, He; Logan, Bruce E.

    2009-01-01

    of microbial consortia specifically acclimated for biomass breakdown. A mixed culture that was developed to have a high saccharification rate with corn stover was added to singlechamber, air-cathode MFCs acclimated for power production using glucose. The MFC

  5. Sewage sludge as a biomass energy source

    Directory of Open Access Journals (Sweden)

    Pavel Kolat

    2013-01-01

    Full Text Available The major part of the dry matter content of sewage sludge consists of nontoxic organic compounds, in general a combination of primary sludge and secondary microbiological sludge. The sludge also contains a substantive amount of inorganic material and a small amount of toxic components. There are many sludge-management options in which production of energy is one of the key treatment steps. The most important options are anaerobic digestion, co-digestion, incineration in combination with energy recovery and co-incineration in coal-fired power plants. The goal of our applied research is to verify, if the sludge from waste water treatment plants may be used as a biomass energy source in respect of the EU legislation, which would comply with emission limits or the proposal of energy process optimizing the preparation of coal/sludge mixture for combustion in the existing fluid bed boilers in the Czech Republic. The paper discusses the questions of thermal usage of mechanically drained stabilized sewage sludge from the waste water treatment plants in the boiler with circulated fluid layer. The paper describes methods of thermal analysis of coal, sewage sludge and its mixtures, mud transport to the circulating fluidised bed boiler, effects on efficiency, operational reliability of the combustion equipment, emissions and solid combustion residues.

  6. A global analysis of soil microbial biomass carbon, nitrogen and phosphorus in terrestrial ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Xiaofeng [ORNL; Thornton, Peter E [ORNL; Post, Wilfred M [ORNL

    2013-01-01

    Soil microbes play a pivotal role in regulating land-atmosphere interactions; the soil microbial biomass carbon (C), nitrogen (N), phosphorus (P) and C:N:P stoichiometry are important regulators for soil biogeochemical processes; however, the current knowledge on magnitude, stoichiometry, storage, and spatial distribution of global soil microbial biomass C, N, and P is limited. In this study, 3087 pairs of data points were retrieved from 281 published papers and further used to summarize the magnitudes and stoichiometries of C, N, and P in soils and soil microbial biomass at global- and biome-levels. Finally, global stock and spatial distribution of microbial biomass C and N in 0-30 cm and 0-100 cm soil profiles were estimated. The results show that C, N, and P in soils and soil microbial biomass vary substantially across biomes; the fractions of soil nutrient C, N, and P in soil microbial biomass are 1.6% in a 95% confidence interval of (1.5%-1.6%), 2.9% in a 95% confidence interval of (2.8%-3.0%), and 4.4% in a 95% confidence interval of (3.9%-5.0%), respectively. The best estimates of C:N:P stoichiometries for soil nutrients and soil microbial biomass are 153:11:1, and 47:6:1, respectively, at global scale, and they vary in a wide range among biomes. Vertical distribution of soil microbial biomass follows the distribution of roots up to 1 m depth. The global stock of soil microbial biomass C and N were estimated to be 15.2 Pg C and 2.3 Pg N in the 0-30 cm soil profiles, and 21.2 Pg C and 3.2 Pg N in the 0-100 cm soil profiles. We did not estimate P in soil microbial biomass due to data shortage and insignificant correlation with soil total P and climate variables. The spatial patterns of soil microbial biomass C and N were consistent with those of soil organic C and total N, i.e. high density in northern high latitude, and low density in low latitudes and southern hemisphere.

  7. Microbial Biomass Changes during Decomposition of Plant Residues in a Lixisol

    Directory of Open Access Journals (Sweden)

    Kachaka, SK.

    2003-01-01

    Full Text Available A lixisol was amended with four different alley cropping species: Senna siamea, Leucaena leucocephala, Dactyladenia barteri and Flemingia macrophylla. Soil samples were incubated for 140 days at 25 °C and the soil microbial biomass was determined by the ninhydrin extraction method along the incubation period. The soil microbial biomass values ranged between 80 and 600 mg.kg-1 and followed, in all cases, the decreasing order: Leucaena> Senna> Flemingia> Dactyladenia.

  8. Microbial biomass carbon and enzyme activities of urban soils in Beijing.

    Science.gov (United States)

    Wang, Meie; Markert, Bernd; Shen, Wenming; Chen, Weiping; Peng, Chi; Ouyang, Zhiyun

    2011-07-01

    To promote rational and sustainable use of soil resources and to maintain the urban soil quality, it is essential to assess urban ecosystem health. In this study, the microbiological properties of urban soils in Beijing and their spatial distribution patterns across the city were evaluated based on measurements of microbial biomass carbon and urease and invertase activities of the soils for the purpose of assessing the urban ecosystem health of Beijing. Grid sampling design, normal Kriging technique, and the multiple comparisons among different land use types were used in soil sampling and data treatment. The inherent chemical characteristics of urban soils in Beijing, e.g., soil pH, electronic conductivity, heavy metal contents, total N, P and K contents, and soil organic matter contents were detected. The size and diversity of microbial community and the extent of microbial activity in Beijing urban soils were measured as the microbial biomass carbon content and the ratio of microbial biomass carbon content to total soil organic carbon. The microbial community health measured in terms of microbial biomass carbon, urease, and invertase activities varied with the organic substrate and nutrient contents of the soils and were not adversely affected by the presence of heavy metals at p urban soils influenced the nature and activities of the microbial communities.

  9. Bioactive natural products from novel microbial sources.

    Science.gov (United States)

    Challinor, Victoria L; Bode, Helge B

    2015-09-01

    Despite the importance of microbial natural products for human health, only a few bacterial genera have been mined for the new natural products needed to overcome the urgent threat of antibiotic resistance. This is surprising, given that genome sequencing projects have revealed that the capability to produce natural products is not a rare feature among bacteria. Even the bacteria occurring in the human microbiome produce potent antibiotics, and thus potentially are an untapped resource for novel compounds, potentially with new activities. This review highlights examples of bacteria that should be considered new sources of natural products, including anaerobes, pathogens, and symbionts of humans, insects, and nematodes. Exploitation of these producer strains, combined with advances in modern natural product research methodology, has the potential to open the way for a new golden age of microbial therapeutics. © 2015 New York Academy of Sciences.

  10. Biomass production from electricity using ammonia as an electron carrier in a reverse microbial fuel cell.

    Directory of Open Access Journals (Sweden)

    Wendell O Khunjar

    Full Text Available The storage of renewable electrical energy within chemical bonds of biofuels and other chemicals is a route to decreasing petroleum usage. A critical challenge is the efficient transfer of electrons into a biological host that can covert this energy into high energy organic compounds. In this paper, we describe an approach whereby biomass is grown using energy obtained from a soluble mediator that is regenerated electrochemically. The net result is a separate-stage reverse microbial fuel cell (rMFC that fixes CO₂ into biomass using electrical energy. We selected ammonia as a low cost, abundant, safe, and soluble redox mediator that facilitated energy transfer to biomass. Nitrosomonas europaea, a chemolithoautotroph, was used as the biocatalyst due to its inherent capability to utilize ammonia as its sole energy source for growth. An electrochemical reactor was designed for the regeneration of ammonia from nitrite, and current efficiencies of 100% were achieved. Calculations indicated that overall bioproduction efficiency could approach 2.7±0.2% under optimal electrolysis conditions. The application of chemolithoautotrophy for industrial bioproduction has been largely unexplored, and results suggest that this and related rMFC platforms may enable biofuel and related biochemical production.

  11. Ambient ultraviolet radiation in the Arctic reduces root biomass and alters microbial community composition but has no effects on microbial biomass

    DEFF Research Database (Denmark)

    Rinnan, R.; Keinänen, M.M.; Kasurinen, A.

    2005-01-01

    We assessed the effects of ambient solar ultraviolet (UV) radiation on below-ground parameters in an arctic heath in north-eastern Greenland. We hypothesized that the current UV fluxes would reduce root biomass and mycorrhizal colonization and that these changes would lead to lower soil microbial...... biomass and altered microbial community composition. These hypotheses were tested on cored soil samples from a UV reduction experiment with three filter treatments (Mylar, 60% UV-B reduction; Lexan, up to 90% UV-B reduction+UV-A reduction; UV transparent Teflon, filter control) and an open control...... treatment in two study sites after 3 years' manipulation. Reduction of both UV-A and UV-B radiation caused over 30% increase in the root biomass of Vaccinium uliginosum, which was the dominant plant species. UV reduction had contrasting effects on ericoid mycorrhizal colonization of V. uliginosum roots...

  12. Alterations in soil microbial community composition and biomass following agricultural land use change.

    Science.gov (United States)

    Zhang, Qian; Wu, Junjun; Yang, Fan; Lei, Yao; Zhang, Quanfa; Cheng, Xiaoli

    2016-11-04

    The effect of agricultural land use change on soil microbial community composition and biomass remains a widely debated topic. Here, we investigated soil microbial community composition and biomass [e.g., bacteria (B), fungi (F), Arbuscular mycorrhizal fungi (AMF) and Actinomycete (ACT)] using phospholipid fatty acids (PLFAs) analysis, and basal microbial respiration in afforested, cropland and adjacent uncultivated soils in central China. We also investigated soil organic carbon and nitrogen (SOC and SON), labile carbon and nitrogen (LC and LN), recalcitrant carbon and nitrogen (RC and RN), pH, moisture, and temperature. Afforestation averaged higher microbial PLFA biomass compared with cropland and uncultivated soils with higher values in top soils than deep soils. The microbial PLFA biomass was strongly correlated with SON and LC. Higher SOC, SON, LC, LN, moisture and lower pH in afforested soils could be explained approximately 87.3% of total variation of higher total PLFAs. Afforestation also enhanced the F: B ratios compared with cropland. The basal microbial respiration was higher while the basal microbial respiration on a per-unit-PLFA basis was lower in afforested land than adjacent cropland and uncultivated land, suggesting afforestation may increase soil C utilization efficiency and decrease respiration loss in afforested soils.

  13. [Effects of altitudes on soil microbial biomass and enzyme activity in alpine-gorge regions.

    Science.gov (United States)

    Cao, Rui; Wu, Fu Zhong; Yang, Wan Qin; Xu, Zhen Feng; Tani, Bo; Wang, Bin; Li, Jun; Chang, Chen Hui

    2016-04-22

    In order to understand the variations of soil microbial biomass and soil enzyme activities with the change of altitude, a field incubation was conducted in dry valley, ecotone between dry valley and mountain forest, subalpine coniferous forest, alpine forest and alpine meadow from 1563 m to 3994 m of altitude in the alpine-gorge region of western Sichuan. The microbial biomass carbon and nitrogen, and the activities of invertase, urease and acid phosphorus were measured in both soil organic layer and mineral soil layer. Both the soil microbial biomass and soil enzyme activities showed the similar tendency in soil organic layer. They increased from 2158 m to 3028 m, then decreased to the lowest value at 3593 m, and thereafter increased until 3994 m in the alpine-gorge region. In contrast, the soil microbial biomass and soil enzyme activities in mineral soil layer showed the trends as, the subalpine forest at 3028 m > alpine meadow at 3994 m > montane forest ecotone at 2158 m > alpine forest at 3593 m > dry valley at 1563 m. Regardless of altitudes, soil microbial biomass and soil enzyme activities were significantly higher in soil organic layer than in mineral soil layer. The soil microbial biomass was significantly positively correlated with the activities of the measured soil enzymes. Moreover, both the soil microbial biomass and soil enzyme activities were significantly positively correlated with soil water content, organic carbon, and total nitrogen. The activity of soil invertase was significantly positively correlated with soil phosphorus content, and the soil acid phosphatase was so with soil phosphorus content and soil temperature. In brief, changes in vegetation and other environmental factors resulting from altitude change might have strong effects on soil biochemical properties in the alpine-gorge region.

  14. Production of microbial biomass protein by sequential culture fermentation of Arachniotus sp., and Candida utilis

    International Nuclear Information System (INIS)

    Ahmed, S.; Ahmad, F.; Hashmi, A.S.

    2010-01-01

    Sequential culture fermentation by Arachniotus sp. at 35 deg. C for 72 h and followed by Candida utilis fermentation at 35 deg. C for 72 h more resulted in higher production of microbial biomass protein. 6% (w/v) corn stover, 0.0075% CaCl/sub 2/.2H/sub 2/O, 0.005% MgSO/sub 4/.7H/sub 2/O, 0.01% KH/sub 2/PO/sub 4/, C:N ratio of 30:1 and 1% molasses gave higher microbial biomass protein production by the sequential culture fermentation of Arachniotus sp., and C. utilis. The mixed microbial biomass protein produced in the 75-L fermentor contained 16.41%, 23.51%, 10.9%, 12.11% and 0.12% true protein, crude protein, crude fiber, ash and RNA content, respectively. The amino acid profile of final mixed microbial biomass protein showed that it was enriched with essential amino acids. Thus, the potential utilization of corn stover can minimize the cost for growth of these microorganisms and enhance microbial biomass protein production by sequential culture fermentation. (author)

  15. [Effects of bio-crust on soil microbial biomass and enzyme activities in copper mine tailings].

    Science.gov (United States)

    Chen, Zheng; Yang, Gui-de; Sun, Qing-ye

    2009-09-01

    Bio-crust is the initial stage of natural primary succession in copper mine tailings. With the Yangshanchong and Tongguanshan copper mine tailings in Tongling City of Anhui Province as test objects, this paper studied the soil microbial biomass C and N and the activities of dehydrogenase, catalase, alkaline phosphatase, and urease under different types of bio-crust. The bio-crusts improved the soil microbial biomass and enzyme activities in the upper layer of the tailings markedly. Algal crust had the best effect in improving soil microbial biomass C and N, followed by moss-algal crust, and moss crust. Soil microflora also varied with the type of bio-crust. No'significant difference was observed in the soil enzyme activities under the three types of bio-crust. Soil alkaline phosphatase activity was significantly positively correlated with soil microbial biomass and dehydrogenase and urease activities, but negatively correlated with soil pH. In addition, moss rhizoid could markedly enhance the soil microbial biomass and enzyme activities in moss crust rhizoid.

  16. Changes in Soil Enzyme Activities and Microbial Biomass after Revegetation in the Three Gorges Reservoir, China

    Directory of Open Access Journals (Sweden)

    Qingshui Ren

    2018-05-01

    Full Text Available Soil enzymes and microbes are central to the decomposition of plant and microbial detritus, and play important roles in carbon, nitrogen, and phosphorus biogeochemistry cycling at the ecosystem level. In the present study, we characterized the soil enzyme activity and microbial biomass in revegetated (with Taxodium distichum (L. Rich. and Cynodon dactylon (L. Pers. versus unplanted soil in the riparian zone of the Three Gorges Dam Reservoir (TGDR, in order to quantify the effect of revegetation on the edaphic microenvironment after water flooding in situ. After revegetation, the soil physical and chemical properties in revegetated soil showed significant differences to those in unplanted soil. The microbial biomass carbon and phosphorus in soils of T. distichum were significantly higher than those in C. dactylon and unplanted soils, respectively. The microbial biomass nitrogen in revegetated T. distichum and C. dactylon soils was significantly increased by 273% and 203%, respectively. The enzyme activities of T. distichum and C. dactylon soils displayed no significant difference between each other, but exhibited a great increase compared to those of the unplanted soil. Elements ratio (except C/N (S did not vary significantly between T. distichum and C. dactylon soils; meanwhile, a strong community-level elemental homeostasis in the revegetated soils was found. The correlation analyses demonstrated that only microbial biomass carbon and phosphorus had a significantly positive relationship with soil enzyme activities. After revegetation, both soil enzyme activities and microbial biomasses were relatively stable in the T. distichum and C. dactylon soils, with the wooded soil being more superior. The higher enzyme activities and microbial biomasses demonstrate the C, N, and P cycling and the maintenance of soil quality in the riparian zone of the TGDR.

  17. Microbial biomass in compost during colonization of Agaricus bisporus

    NARCIS (Netherlands)

    Vos, Aurin M.; Heijboer, Amber; Boschker, Henricus T.S.; Bonnet, Barbara; Lugones, Luis G.; Wösten, Han A.B.

    2017-01-01

    Agaricus bisporus mushrooms are commercially produced on a microbe rich compost. Here, fungal and bacterial biomass was quantified in compost with and without colonization by A. bisporus. Chitin content, indicative of total fungal biomass, increased during a 26-day period from 576 to 779 nmol

  18. Microbial biomass in faeces of dairy cows affected by a nitrogen deficient diet.

    Science.gov (United States)

    Jost, Daphne Isabel; Aschemann, Martina; Lebzien, Peter; Joergensen, Rainer Georg; Sundrum, Albert

    2013-04-01

    Since more than half of the faecal nitrogen (N) originates from microbial N, the objective of the study was to develop a method for quantitatively detecting microbial biomass and portion of living microorganisms in dairy cattle faeces, including bacteria, fungi and archaea. Three techniques were tested: (1) the chloroform fumigation extraction (CFE) method, (2) detection of the fungal cell-membrane component ergosterol and (3) analysis of the cell wall components fungal glucosamine and bacterial muramic acid. In a second step, an N deficient (ND) and an N balanced (NB) diets were compared with respect to the impacts on faecal C and N fractions, microbial indices and digestibility. The mean values of microbial biomass C and N concentrations averaged around 37 and 4.9 mg g(-1) DM, respectively. Ergosterol, together with fungal glucosamine and bacterial muramic acid, revealed a 25% fungal C in relation to the total microbial C content in dairy cattle faeces. Changes in ruminal N supply showed significant effects on faecal composition. Faecal concentrations of NDF, hemicelluloses and undigested dietary N and the total C/N ratio were significantly higher in ND treatment compared to the NB treatment. N deficiency was reflected also by a higher microbial biomass C/N ratio. It was concluded that the assessment of microbial indices provides valuable information with respect to diet effects on faecal composition and the successive decomposition. Further studies should be conducted to explore the potentials for minimising nutrient losses from faeces.

  19. Forest wildfire increases soil microbial biomass C:N:P stoichiometry in long-term effects

    Science.gov (United States)

    Zhou, Xuan

    2017-04-01

    Boreal forest fire strongly influences carbon (C) stock in permafrost soil by thawing permafrost table which accelerated microbe decomposition process. We studied soil microbial biomass stoichiometry in a gradient of four (3 yr, 25 yr, 46 yr and more than 100 yr) ages since fire in Canada boreal forest. Soil microbial biomass (MB) in long-term after fire is significantly higher than in short-term. MB C and nitrogen (N) were mainly dominated by corresponding soil element concentration and inorganic P, while MB phosphorus (P) changes were fully explained by soil N. Fire ages and soil temperature positively increased MB N and P, indicating the negative impact by fire. Microbial C:N:P gradually increased with fire ages from 15:2:1 to 76:6:1 and then drop down to 17:2:1 in the oldest fire ages. The degree of homeostasis of microbial C, N and P are close to 1 indicates non-homoeostasis within microbial elements, while it of C:N:P is close to 8 shows a strong homeostasis within element ratios and proved microbial stoichiometric ratio is not driven by soil element ratios. In conclusion, i) microbial biomass elements highly depends on soil nutrient supply rather than fire ages; ii) wildfire decreased microbial stoichiometry immediate after fire but increased with years after fire (YF) which at least 3 times higher than > 100 fire ages; iii) microbial biomass C, N and P deviated from strict homeostasis but C:N:P ratio reflects stronger homeostasis.

  20. Bacterial synergism in lignocellulose biomass degradation : Complementary roles of degraders as influenced by complexity of the carbon source

    NARCIS (Netherlands)

    Cortes Tolalpa, Larisa; Falcao Salles, Joana; van Elsas, Jan

    2017-01-01

    Lignocellulosic biomass (LCB) is an attractive source of carbon for the production of sugars and other chemicals. Due to its inherent complexity and heterogeneity, efficient biodegradation requires the actions of different types of hydrolytic enzymes. In nature, complex microbial communities that

  1. Application of next-generation sequencing methods for microbial monitoring of anaerobic digestion of lignocellulosic biomass.

    Science.gov (United States)

    Bozan, Mahir; Akyol, Çağrı; Ince, Orhan; Aydin, Sevcan; Ince, Bahar

    2017-09-01

    The anaerobic digestion of lignocellulosic wastes is considered an efficient method for managing the world's energy shortages and resolving contemporary environmental problems. However, the recalcitrance of lignocellulosic biomass represents a barrier to maximizing biogas production. The purpose of this review is to examine the extent to which sequencing methods can be employed to monitor such biofuel conversion processes. From a microbial perspective, we present a detailed insight into anaerobic digesters that utilize lignocellulosic biomass and discuss some benefits and disadvantages associated with the microbial sequencing techniques that are typically applied. We further evaluate the extent to which a hybrid approach incorporating a variation of existing methods can be utilized to develop a more in-depth understanding of microbial communities. It is hoped that this deeper knowledge will enhance the reliability and extent of research findings with the end objective of improving the stability of anaerobic digesters that manage lignocellulosic biomass.

  2. Assessment of microbial activity and biomass in different soils exposed to nicosulfuron

    Directory of Open Access Journals (Sweden)

    Ljiljana Šantrić

    2014-09-01

    Full Text Available The effects of the herbicide nicosulfuron on the abundance of cellulolytic and proteolytic microorganisms, activity of β-glucosidase and protease enzymes, and microbial phosphorus biomass were examined. A laboratory bioassay was set up on two types of agricultural soils differing in physicochemical properties. The following concentrations were tested: 0.3, 0.6, 3.0 and 30.0 mg a.i./kg of soil. Samples were collected 3, 7, 14, 30 and 45 days after treatment with nicosulfuron. The results showed that nicosulfuron significantly reduced the abundance of cellulolytic microorganisms in both soils, as well as microbial biomass phosphorus in sandy loam soil. The herbicide was found to stimulate β-glucosidase and protease activity in both types of soil and microbial biomass phosphorus in loamy soil. Proteolytic microorganisms remained unaffected by nicosulfuron.

  3. Short-term parasite-infection alters already the biomass, activity and functional diversity of soil microbial communities

    Science.gov (United States)

    Li, Jun-Min; Jin, Ze-Xin; Hagedorn, Frank; Li, Mai-He

    2014-11-01

    Native parasitic plants may be used to infect and control invasive plants. We established microcosms with invasive Mikania micrantha and native Coix lacryma-jobi growing in mixture on native soils, with M. micrantha being infected by parasitic Cuscuta campestris at four intensity levels for seven weeks to estimate the top-down effects of plant parasitism on the biomass and functional diversity of soil microbial communities. Parasitism significantly decreased root biomass and altered soil microbial communities. Soil microbial biomass decreased, but soil respiration increased at the two higher infection levels, indicating a strong stimulation of soil microbial metabolic activity (+180%). Moreover, a Biolog assay showed that the infection resulted in a significant change in the functional diversity indices of soil microbial communities. Pearson correlation analysis indicated that microbial biomass declined significantly with decreasing root biomass, particularly of the invasive M. micrantha. Also, the functional diversity indices of soil microbial communities were positively correlated with soil microbial biomass. Therefore, the negative effects on the biomass, activity and functional diversity of soil microbial community by the seven week long plant parasitism was very likely caused by decreased root biomass and root exudation of the invasive M. micrantha.

  4. Microbial Functional Diversity, Biomass and Activity as Affected by Soil Surface Mulching in a Semiarid Farmland.

    Directory of Open Access Journals (Sweden)

    Yufang Shen

    Full Text Available Mulching is widely used to increase crop yield in semiarid regions in northwestern China, but little is known about the effect of different mulching systems on the microbial properties of the soil, which play an important role in agroecosystemic functioning and nutrient cycling. Based on a 4-year spring maize (Zea mays L. field experiment at Changwu Agricultural and Ecological Experimental Station, Shaanxi, we evaluated the responses of soil microbial activity and crop to various management systems. The treatments were NMC (no mulching with inorganic N fertilizer, GMC (gravel mulching with inorganic N fertilizer, FMC (plastic-film mulching with inorganic N fertilizer and FMO (plastic-film mulching with inorganic N fertilizer and organic manure addition. The results showed that the FMO soil had the highest contents of microbial biomass carbon and nitrogen, dehydrogenase activity, microbial activity and Shannon diversity index. The relative use of carbohydrates and amino acids by microbes was highest in the FMO soil, whereas the relative use of polymers, phenolic compounds and amines was highest in the soil in the NMC soil. Compared with the NMC, an increased but no significant trend of biomass production and nitrogen accumulation was observed under the GMC treatment. The FMC and FMO led a greater increase in biomass production than GMC and NMC. Compare with the NMC treatment, FMC increased grain yield, maize biomass and nitrogen accumulation by 62.2, 62.9 and 86.2%, but no significant difference was found between the FMO and FMC treatments. Some soil biological properties, i.e. microbial biomass carbon, microbial biomass nitrogen, being sensitive to the mulching and organic fertilizer, were significant correlated with yield and nitrogen availability. Film mulching over gravel mulching can serve as an effective measure for crop production and nutrient cycling, and plus organic fertilization additions may thus have improvements in the biological

  5. A Statistical Framework for Microbial Source Attribution

    Energy Technology Data Exchange (ETDEWEB)

    Velsko, S P; Allen, J E; Cunningham, C T

    2009-04-28

    This report presents a general approach to inferring transmission and source relationships among microbial isolates from their genetic sequences. The outbreak transmission graph (also called the transmission tree or transmission network) is the fundamental structure which determines the statistical distributions relevant to source attribution. The nodes of this graph are infected individuals or aggregated sub-populations of individuals in which transmitted bacteria or viruses undergo clonal expansion, leading to a genetically heterogeneous population. Each edge of the graph represents a transmission event in which one or a small number of bacteria or virions infects another node thus increasing the size of the transmission network. Recombination and re-assortment events originate in nodes which are common to two distinct networks. In order to calculate the probability that one node was infected by another, given the observed genetic sequences of microbial isolates sampled from them, we require two fundamental probability distributions. The first is the probability of obtaining the observed mutational differences between two isolates given that they are separated by M steps in a transmission network. The second is the probability that two nodes sampled randomly from an outbreak transmission network are separated by M transmission events. We show how these distributions can be obtained from the genetic sequences of isolates obtained by sampling from past outbreaks combined with data from contact tracing studies. Realistic examples are drawn from the SARS outbreak of 2003, the FMDV outbreak in Great Britain in 2001, and HIV transmission cases. The likelihood estimators derived in this report, and the underlying probability distribution functions required to calculate them possess certain compelling general properties in the context of microbial forensics. These include the ability to quantify the significance of a sequence 'match' or &apos

  6. Aspects of using biomass as energy source for power generation

    Directory of Open Access Journals (Sweden)

    Tîrtea Raluca-Nicoleta

    2017-07-01

    Full Text Available Biomass represents an important source of renewable energy in Romania with about 64% of the whole available green energy. Being a priority for the energy sector worldwide, in our country the development stage is poor compared to solar and wind energy. Biomass power plants offer great horizontal economy development, local and regional economic growth with benefic effects on life standard. The paper presents an analysis on biomass to power conversion solutions compared to fossil fuels using two main processes: combustion and gasification. Beside the heating value, which can be considerably higher for fossil fuels compared to biomass, a big difference between fossil fuels and biomass can be observed in the sulphur content. While the biomass sulphur content is between 0 and approximately 1%, the sulphur content of coal can reach 4%. Using coal in power plants requires important investments in installations of flue gas desulfurization. If limestone is used to reduce SO2 emissions, then additional carbon dioxide moles will be released during the production of CaO from CaCO3. Therefore, fossil fuels not only release a high amount of carbon dioxide through burning, but also through the caption of sulphur dioxide, while biomass is considered CO2 neutral. Biomass is in most of the cases represented by residues, so it is a free fuel compared to fossil fuels. The same power plant can be used even if biomass or fossil fuels is used as a feedstock with small differences. The biomass plant could need a drying system due to high moisture content of the biomass, while the coal plant will need a desulfurization installation of flue gas and additional money will be spent with fuel purchasing.

  7. Tracking dynamics of plant biomass composting by changes in substrate structure, microbial community, and enzyme activity

    Directory of Open Access Journals (Sweden)

    Wei Hui

    2012-04-01

    Full Text Available Abstract Background Understanding the dynamics of the microbial communities that, along with their secreted enzymes, are involved in the natural process of biomass composting may hold the key to breaking the major bottleneck in biomass-to-biofuels conversion technology, which is the still-costly deconstruction of polymeric biomass carbohydrates to fermentable sugars. However, the complexity of both the structure of plant biomass and its counterpart microbial degradation communities makes it difficult to investigate the composting process. Results In this study, a composter was set up with a mix of yellow poplar (Liriodendron tulipifera wood-chips and mown lawn grass clippings (85:15 in dry-weight and used as a model system. The microbial rDNA abundance data obtained from analyzing weekly-withdrawn composted samples suggested population-shifts from bacteria-dominated to fungus-dominated communities. Further analyses by an array of optical microscopic, transcriptional and enzyme-activity techniques yielded correlated results, suggesting that such population shifts occurred along with early removal of hemicellulose followed by attack on the consequently uncovered cellulose as the composting progressed. Conclusion The observed shifts in dominance by representative microbial groups, along with the observed different patterns in the gene expression and enzymatic activities between cellulases, hemicellulases, and ligninases during the composting process, provide new perspectives for biomass-derived biotechnology such as consolidated bioprocessing (CBP and solid-state fermentation for the production of cellulolytic enzymes and biofuels.

  8. Tracking dynamics of plant biomass composting by changes in substrate structure, microbial community, and enzyme activity

    Science.gov (United States)

    2012-01-01

    Background Understanding the dynamics of the microbial communities that, along with their secreted enzymes, are involved in the natural process of biomass composting may hold the key to breaking the major bottleneck in biomass-to-biofuels conversion technology, which is the still-costly deconstruction of polymeric biomass carbohydrates to fermentable sugars. However, the complexity of both the structure of plant biomass and its counterpart microbial degradation communities makes it difficult to investigate the composting process. Results In this study, a composter was set up with a mix of yellow poplar (Liriodendron tulipifera) wood-chips and mown lawn grass clippings (85:15 in dry-weight) and used as a model system. The microbial rDNA abundance data obtained from analyzing weekly-withdrawn composted samples suggested population-shifts from bacteria-dominated to fungus-dominated communities. Further analyses by an array of optical microscopic, transcriptional and enzyme-activity techniques yielded correlated results, suggesting that such population shifts occurred along with early removal of hemicellulose followed by attack on the consequently uncovered cellulose as the composting progressed. Conclusion The observed shifts in dominance by representative microbial groups, along with the observed different patterns in the gene expression and enzymatic activities between cellulases, hemicellulases, and ligninases during the composting process, provide new perspectives for biomass-derived biotechnology such as consolidated bioprocessing (CBP) and solid-state fermentation for the production of cellulolytic enzymes and biofuels. PMID:22490508

  9. Biomass as an energy source: an Asian-Pacific perspective

    Energy Technology Data Exchange (ETDEWEB)

    Kyi, Lwin [Energy Resources Section, Environment and Natural Resources Management Division, Economic and Social Commission for Asia and the Pacific, United Nations Building, Bangkok (Thailand)

    1995-12-01

    Biomass is the most commonly used renewable source of energy in the region covered by the Economic and Social Commission for Asia and the Pacific, making up an average of 50% of energy supplies in the developing countries. However, experience over the past one and a half decades in rural energy supply in the ESCAP region suggests that biomass resources are unlikely to compete with conventional supplies in meeting expanded rural energy needs for fuel, electricity and fertilizers. Nevertheless, biomass, especially wood and agricultural residues, will remain the main energy source in most countries of the region for the next two decades. The development of biomass energy systems in the ESCAP region is at different stages for different types of biomass resources. Efforts have been concentrated in six areas: direct combustion, gasification, co-generation, anaerobic digestion, densification and dendrothermal processes. Among the biomass technologies presently being promoted in the region, biogas and cooking stove programmes are the largest in terms of scale, operations and coverage. Co-generation is promising as its economic advantages make it attractive to industrial consumers, particularly the booming food and fibre production and processing industries, which produce enough biomass feedstock to warrant installing co-generation facilities. Despite its potential, the production of liquid fuel from energy crops is presently taking place in only a few countries. The major constraints on extending the use of biomass include the difficulty of assessing resources, poor local acceptance of technology (mainly for social and economic reasons), lack of financial resources and manpower, environmental concerns, the absence of up-to-date local technology and the lack of after-sales services. Appropriate technologies to develop and harness the region`s vast biomass resource base to augment energy supplies, particularly in rural areas, has been a major issue in the developing

  10. Biomass as an energy source: an Asian-Pacific perspective

    International Nuclear Information System (INIS)

    Lwin Kyi

    1995-01-01

    Biomass is the most commonly used renewable source of energy in the region covered by the Economic and Social Commission for Asia and the Pacific, making up an average of 50% of energy supplies in the developing countries. However, experience over the past one and a half decades in rural energy supply in the ESCAP region suggests that biomass resources are unlikely to compete with conventional supplies in meeting expanded rural energy needs for fuel, electricity and fertilizers. Nevertheless, biomass, especially wood and agricultural residues, will remain the main energy source in most countries of the region for the next two decades. The development of biomass energy systems in the ESCAP region is at different stages for different types of biomass resources. Efforts have been concentrated in six areas: direct combustion, gasification, co-generation, anaerobic digestion, densification and dendrothermal processes. Among the biomass technologies presently being promoted in the region, biogas and cooking stove programmes are the largest in terms of scale, operations and coverage. Co-generation is promising as its economic advantages make it attractive to industrial consumers, particularly the booming food and fibre production and processing industries, which produce enough biomass feedstock to warrant installing co-generation facilities. Despite its potential, the production of liquid fuel from energy crops is presently taking place in only a few countries. The major constraints on extending the use of biomass include the difficulty of assessing resources, poor local acceptance of technology (mainly for social and economic reasons), lack of financial resources and manpower, environmental concerns, the absence of up-to-date local technology and the lack of after-sales services. Appropriate technologies to develop and harness the region's vast biomass resource base to augment energy supplies, particularly in rural areas, has been a major issue in the developing

  11. Assessment of tillage systems in organic farming: influence of soil structure on microbial biomass. First results

    OpenAIRE

    Vian, Jean François; Peigné, Joséphine; Chaussod, Rémi; Roger-Estrade, Jean

    2007-01-01

    Soil tillage modifies environmental conditions of soil microorganisms and their ability to release nitrogen. We compare the influence of reduced tillage (RT) and mouldboard ploughing (MP) on the soil microbial functioning in organic farming. In order to connect soil structure generated by these tillage systems on the soil microbial biomass we adopt a particular sampling scheme based on the morphological characterisation of the soil structure by the description of the soil profile. This method...

  12. Salmonella source attribution based on microbial subtyping

    DEFF Research Database (Denmark)

    Barco, Lisa; Barrucci, Federica; Olsen, John Elmerdahl

    2013-01-01

    Source attribution of cases of food-borne disease represents a valuable tool for identifying and prioritizing effective food-safety interventions. Microbial subtyping is one of the most common methods to infer potential sources of human food-borne infections. So far, Salmonella microbial subtyping...... source attribution through microbial subtyping approach. It summarizes the available microbial subtyping attribution models and discusses the use of conventional phenotypic typing methods, as well as of the most commonly applied molecular typing methods in the European Union (EU) laboratories...

  13. Conversion of biomass into energy source

    International Nuclear Information System (INIS)

    Antonescu, S.; Garjoaba, M.; Antonescu, A.

    2005-01-01

    This study assists the identification of possible application and markets of the CHP-plants in the NAS states, and forms the first part of a detailed study on economical and ecological prospects of small scale and large heat pipe reformers in NAS. It is well known that the energy strategy of the European Union, foresees the increase of the participation of the renewable energy from the total of the energy resources of the European Union, up to 12% in 2010. This participation is of a great importance for the adequate reduction of green house effect gases. From the energy production point of view it is proven the fact that in 2010 the production of renewable energy will be: electricity - 675 tWh; heat - 80 Mtoe (930 TWh). From the above mentioned energy demand, the biomass will cover: electricity - 230 TWh-34,1%; heat - 75 Mtoe (93,8%)

  14. Extraction of solubles from plant biomass for use as microbial growth stimulant and methods related thereto

    Energy Technology Data Exchange (ETDEWEB)

    Lau, Ming Woei

    2015-12-08

    A method for producing a microbial growth stimulant (MGS) from a plant biomass is described. In one embodiment, an ammonium hydroxide solution is used to extract a solution of proteins and ammonia from the biomass. Some of the proteins and ammonia are separated from the extracted solution to provide the MGS solution. The removed ammonia can be recycled and the proteins are useful as animal feeds. In one embodiment, the method comprises extracting solubles from pretreated lignocellulosic biomass with a cellulase enzyme-producing growth medium (such T. reesei) in the presence of water and an aqueous extract.

  15. Effects of vegetation type on microbial biomass carbon and nitrogen in subalpine mountain forest soils.

    Science.gov (United States)

    Ravindran, Anita; Yang, Shang-Shyng

    2015-08-01

    Microbial biomass plays an important role in nutrient transformation and conservation of forest and grassland ecosystems. The objective of this study was to determine the microbial biomass among three vegetation types in subalpine mountain forest soils of Taiwan. Tatachia is a typical high-altitude subalpine temperate forest ecosystem in Taiwan with an elevation of 1800-3952 m and consists of three vegetation types: spruce, hemlock, and grassland. Three plots were selected in each vegetation type. Soil samples were collected from the organic layer, topsoil, and subsoil. Microbial biomass carbon (Cmic) was determined by the chloroform fumigation-extraction method, and microbial biomass nitrogen (Nmic) was determined from the total nitrogen (Ntot) released during fumigation-extraction. Bacteria, actinomycetes, fungi, cellulolytic microbes, phosphate-solubilizing microbes, and nitrogen-fixing microbes were also counted. The Cmic and Nmic were highest in the surface soil and declined with the soil depth. These were also highest in spruce soils, followed by in hemlock soils, and were lowest in grassland soils. Cmic and Nmic had the highest values in the spring season and the lowest values in the winter season. Cmic and Nmic had significantly positive correlations with total organic carbon (Corg) and Ntot. Contributions of Cmic and Nmic, respectively, to Corg and Ntot indicated that the microbial biomass was immobilized more in spruce and hemlock soils than in grassland soils. Microbial populations of the tested vegetation types decreased with increasing soil depth. Cmic and Nmic were high in the organic layer and decreased with the depth of layers. These values were higher for spruce and hemlock soils than for grassland soils. Positive correlations were observed between Cmic and Nmic and between Corg and Ntot. Copyright © 2014. Published by Elsevier B.V.

  16. Trichoderma Biofertilizer Links to Altered Soil Chemistry, Altered Microbial Communities, and Improved Grassland Biomass

    Directory of Open Access Journals (Sweden)

    Fengge Zhang

    2018-04-01

    Full Text Available In grasslands, forage and livestock production results in soil nutrient deficits as grasslands typically receive no nutrient inputs, leading to a loss of grassland biomass. The application of mature compost has been shown to effectively increase grassland nutrient availability. However, research on fertilization regime influence and potential microbial ecological regulation mechanisms are rarely conducted in grassland soil. We conducted a two-year experiment in meadow steppe grasslands, focusing on above- and belowground consequences of organic or Trichoderma biofertilizer applications and potential soil microbial ecological mechanisms underlying soil chemistry and microbial community responses. Grassland biomass significantly (p = 0.019 increased following amendment with 9,000 kg ha−1 of Trichoderma biofertilizer (composted cattle manure + inoculum compared with other assessed organic or biofertilizer rates, except for BOF3000 (fertilized with 3,000 kg ha−1 biofertilizer. This rate of Trichoderma biofertilizer treatment increased soil antifungal compounds that may suppress pathogenic fungi, potentially partially responsible for improved grassland biomass. Nonmetric multidimensional scaling (NMDS revealed soil chemistry and fungal communities were all separated by different fertilization regime. Trichoderma biofertilizer (9,000 kg ha−1 increased relative abundances of Archaeorhizomyces and Trichoderma while decreasing Ophiosphaerella. Trichoderma can improve grassland biomass, while Ophiosphaerella has the opposite effect as it may secrete metabolites causing grass necrosis. Correlations between soil properties and microbial genera showed plant-available phosphorus may influence grassland biomass by increasing Archaeorhizomyces and Trichoderma while reducing Ophiosphaerella. According to our structural equation modeling (SEM, Trichoderma abundance was the primary contributor to aboveground grassland biomass. Our results suggest Trichoderma

  17. Trichoderma Biofertilizer Links to Altered Soil Chemistry, Altered Microbial Communities, and Improved Grassland Biomass.

    Science.gov (United States)

    Zhang, Fengge; Huo, Yunqian; Cobb, Adam B; Luo, Gongwen; Zhou, Jiqiong; Yang, Gaowen; Wilson, Gail W T; Zhang, Yingjun

    2018-01-01

    In grasslands, forage and livestock production results in soil nutrient deficits as grasslands typically receive no nutrient inputs, leading to a loss of grassland biomass. The application of mature compost has been shown to effectively increase grassland nutrient availability. However, research on fertilization regime influence and potential microbial ecological regulation mechanisms are rarely conducted in grassland soil. We conducted a two-year experiment in meadow steppe grasslands, focusing on above- and belowground consequences of organic or Trichoderma biofertilizer applications and potential soil microbial ecological mechanisms underlying soil chemistry and microbial community responses. Grassland biomass significantly ( p = 0.019) increased following amendment with 9,000 kg ha -1 of Trichoderma biofertilizer (composted cattle manure + inoculum) compared with other assessed organic or biofertilizer rates, except for BOF3000 (fertilized with 3,000 kg ha -1 biofertilizer). This rate of Trichoderma biofertilizer treatment increased soil antifungal compounds that may suppress pathogenic fungi, potentially partially responsible for improved grassland biomass. Nonmetric multidimensional scaling (NMDS) revealed soil chemistry and fungal communities were all separated by different fertilization regime. Trichoderma biofertilizer (9,000 kg ha -1 ) increased relative abundances of Archaeorhizomyces and Trichoderma while decreasing Ophiosphaerella . Trichoderma can improve grassland biomass, while Ophiosphaerella has the opposite effect as it may secrete metabolites causing grass necrosis. Correlations between soil properties and microbial genera showed plant-available phosphorus may influence grassland biomass by increasing Archaeorhizomyces and Trichoderma while reducing Ophiosphaerella . According to our structural equation modeling (SEM), Trichoderma abundance was the primary contributor to aboveground grassland biomass. Our results suggest Trichoderma

  18. Biomass burning: A significant source of nutrients for Andean rainforests

    Science.gov (United States)

    Fabian, P. F.; Rollenbeck, R.; University Of Marburg, Germany

    2010-12-01

    Regular rain and fogwater sampling in the Podocarpus National Park,on the humid eastern slopes of the Ecuadorian Andes,has been carried out since 2002.The samples,accumulated over about 1-week intervals,were analysed for pH,conductivity,and major ions (K+, Na+, NH4+, Ca2+, Mg2+, Cl-, SO4 2-, NO3-, PO4 3- ).Annual deposition rates of these ions which, due to poor acidic soils with low mineralization rates,constitute the dominant nutrient supply to the mountaineous rainforests, and major ion sources could be determined using back trajectories,along with satellite data. While most of the Na, Cl, and K as well as Ca and Mg input was found to originate from natural oceanic and desert dust sources,respectively (P.Fabian et al.,Adv.Geosci.22,85-94, 2009), NO3, NH4, and about 90% of SO4 (about 10 % is from active volcanoes) are almost entirely due to anthropogenic sources,most likely biomass burning. Industrial and transportation emissions and other pollutants,however,act in a similar way as the precursors produced by biomass burning.For quantifying the impacts of biomass burning vs. those of anthropogenic sources other than biomass burning we used recently established emission inventories,along with simplified model calculations on back trajectories.First results yielding significant contributions of biomass burning will be discussed.

  19. Lignocellulosic Biomass: A Sustainable Bioenergy Source for the Future.

    Science.gov (United States)

    Fatma, Shabih; Hameed, Amir; Noman, Muhammad; Ahmed, Temoor; Shahid, Muhammad; Tariq, Mohsin; Sohail, Imran; Tabassum, Romana

    2018-01-01

    Increasing population and industrialization are continuously oppressing the existing energy resources and depleting the global fuel reservoirs. The elevated pollutions from the continuous consumption of non-renewable fossil fuels also seriously contaminating the surrounding environment. The use of alternate energy sources can be an environment-friendly solution to cope these challenges. Among the renewable energy sources biofuels (biomass-derived fuels) can serve as a better alternative to reduce the reliance on non-renewable fossil fuels. Bioethanol is one of the most widely consumed biofuels of today's world. The main objective of this review is to highlight the significance of lignocellulosic biomass as a potential source for the production of biofuels like bioethanol, biodiesel or biogas. We discuss the application of various methods for the bioconversion of lignocellulosic biomass to end products i.e. biofuels. The lignocellulosic biomass must be pretreated to disintegrate lignocellulosic complexes and to expose its chemical components for downstream processes. After pretreatment, the lignocellulosic biomass is then subjected to saccharification either via acidic or enzymatic hydrolysis. Thereafter, the monomeric sugars resulted from hydrolysis step are further processed into biofuel i.e. bioethanol, biodiesel or butanol etc. through the fermentation process. The fermented impure product is then purified through the distillation process to obtain pure biofuel. Renewable energy sources represent the potential fuel alternatives to overcome the global energy crises in a sustainable and eco-friendly manner. In future, biofuels may replenish the conventional non-renewable energy resources due to their renewability and several other advantages. Lignocellulosic biomass offers the most economical biomass to generate biofuels. However, extensive research is required for the commercial production of an efficient integrated biotransformation process for the production of

  20. Characterization of three plant biomass-degrading microbial consortia by metagenomics- and metasecretomics-based approaches

    NARCIS (Netherlands)

    Jiménez, Diego Javier; Brossi, Maria Julia de Lima; Schuckel, Julia; Kracun, Stjepan Kresimir; Willats, William George Tycho; van Elsas, Jan Dirk

    2016-01-01

    The selection of microbes by enrichment on plant biomass has been proposed as an efficient way to develop new strategies for lignocellulose saccharification. Here, we report an in-depth analysis of soil-derived microbial consortia that were trained to degrade once-used wheat straw (WS1-M),

  1. Soil microbial biomass, activity and community composition along altitudinal gradients in the High Arctic (Billefjorden, Svalbard)

    Czech Academy of Sciences Publication Activity Database

    Kotas, P.; Šantrůčková, H.; Elster, Josef; Kaštovská, E.

    2018-01-01

    Roč. 15, č. 6 (2018), s. 1879-1894 ISSN 1726-4170 R&D Projects: GA MŠk(CZ) LM2015075 Grant - others:GA MŠk LM2010009 Institutional support: RVO:67985939 Keywords : ecosystem * High Arctic * soil microbial biomass Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 3.851, year: 2016

  2. Winter climate change affects growing-season soil microbial biomass and activity in northern hardwood forests

    Science.gov (United States)

    Jorge Durán; Jennifer L. Morse; Peter M. Groffman; John L. Campbell; Lynn M. Christenson; Charles T. Driscoll; Timothy J. Fahey; Melany C. Fisk; Myron J. Mitchell; Pamela H. Templer

    2014-01-01

    Understanding the responses of terrestrial ecosystems to global change remains a major challenge of ecological research. We exploited a natural elevation gradient in a northern hardwood forest to determine how reductions in snow accumulation, expected with climate change, directly affect dynamics of soil winter frost, and indirectly soil microbial biomass and activity...

  3. Effects of 1-Alkyl-3-Methylimidazolium Nitrate on Soil Physical and Chemical Properties and Microbial Biomass.

    Science.gov (United States)

    Zhou, Tongtong; Wang, Jun; Ma, Zhiqiang; Du, Zhongkun; Zhang, Cheng; Zhu, Lusheng; Wang, Jinhua

    2018-05-01

    Ionic liquids (ILs), also called room temperature ILs, are widely applied in many fields on the basis of their unique physical and chemical properties. However, numerous ILs may be released into and gradually accumulate in the environment due to their extensive use and absolute solubility. The effects of 1-alkyl-3-methylimidazolium nitrate ([C n mim]NO 3 , n = 4, 6, 8) on soil pH, conductivity, cation exchange capacity, microbial biomass carbon, and microbial biomass nitrogen were examined at the doses of 1, 10, and 100 mg/kg on days 10, 20, 30, and 40. The results demonstrated that the soil pH decreased and the conductivity increased with increasing IL doses. No significant differences were observed in the soil cation-exchange capacity. All three of the tested ILs decreased the soil microbial biomass carbon and nitrogen. Additionally, there were few differences among the ILs with different alkyl chain lengths on the tested indicators except for the microbial biomass nitrogen. The present study addressed a gap in the literature regarding the effects of the aforementioned ILs with different alkyl side chains on the physicochemical properties of soil, and the results could provide the basic data for future studies on their toxicity to soil organisms, such as earthworms and soil microbes.

  4. Soil microbial biomass, activity and community composition along altitudinal gradients in the High Arctic (Billefjorden, Svalbard

    Directory of Open Access Journals (Sweden)

    P. Kotas

    2018-03-01

    Full Text Available The unique and fragile High Arctic ecosystems are vulnerable to global climate warming. The elucidation of factors driving microbial distribution and activity in arctic soils is essential for a comprehensive understanding of ecosystem functioning and its response to environmental change. The goals of this study were to investigate microbial biomass and activity, microbial community structure (MCS, and their environmental controls in soils along three elevational transects in the coastal mountains of Billefjorden, central Svalbard. Soils from four different altitudes (25, 275, 525 and 765 m above sea level were analyzed for a suite of characteristics including temperature regimes, organic matter content, base cation availability, moisture, pH, potential respiration, and microbial biomass and community structure using phospholipid fatty acids (PLFAs. We observed significant spatial heterogeneity of edaphic properties among transects, resulting in transect-specific effects of altitude on most soil parameters. We did not observe any clear elevation pattern in microbial biomass, and microbial activity revealed contrasting elevational patterns between transects. We found relatively large horizontal variability in MCS (i.e., between sites of corresponding elevation in different transects, mainly due to differences in the composition of bacterial PLFAs, but also a systematic altitudinal shift in MCS related to different habitat preferences of fungi and bacteria, which resulted in high fungi-to-bacteria ratios at the most elevated sites. The biological soil crusts on these most elevated, unvegetated sites can host microbial assemblages of a size and activity comparable to those of the arctic tundra ecosystem. The key environmental factors determining horizontal and vertical changes in soil microbial properties were soil pH, organic carbon content, soil moisture and Mg2+ availability.

  5. Soil microbial biomass, activity and community composition along altitudinal gradients in the High Arctic (Billefjorden, Svalbard)

    Science.gov (United States)

    Kotas, Petr; Šantrůčková, Hana; Elster, Josef; Kaštovská, Eva

    2018-03-01

    The unique and fragile High Arctic ecosystems are vulnerable to global climate warming. The elucidation of factors driving microbial distribution and activity in arctic soils is essential for a comprehensive understanding of ecosystem functioning and its response to environmental change. The goals of this study were to investigate microbial biomass and activity, microbial community structure (MCS), and their environmental controls in soils along three elevational transects in the coastal mountains of Billefjorden, central Svalbard. Soils from four different altitudes (25, 275, 525 and 765 m above sea level) were analyzed for a suite of characteristics including temperature regimes, organic matter content, base cation availability, moisture, pH, potential respiration, and microbial biomass and community structure using phospholipid fatty acids (PLFAs). We observed significant spatial heterogeneity of edaphic properties among transects, resulting in transect-specific effects of altitude on most soil parameters. We did not observe any clear elevation pattern in microbial biomass, and microbial activity revealed contrasting elevational patterns between transects. We found relatively large horizontal variability in MCS (i.e., between sites of corresponding elevation in different transects), mainly due to differences in the composition of bacterial PLFAs, but also a systematic altitudinal shift in MCS related to different habitat preferences of fungi and bacteria, which resulted in high fungi-to-bacteria ratios at the most elevated sites. The biological soil crusts on these most elevated, unvegetated sites can host microbial assemblages of a size and activity comparable to those of the arctic tundra ecosystem. The key environmental factors determining horizontal and vertical changes in soil microbial properties were soil pH, organic carbon content, soil moisture and Mg2+ availability.

  6. Energy Efficiency of Biogas Produced from Different Biomass Sources

    International Nuclear Information System (INIS)

    Begum, Shahida; Nazri, A H

    2013-01-01

    Malaysia has different sources of biomass like palm oil waste, agricultural waste, cow dung, sewage waste and landfill sites, which can be used to produce biogas and as a source of energy. Depending on the type of biomass, the biogas produced can have different calorific value. At the same time the energy, being used to produce biogas is dependent on transportation distance, means of transportation, conversion techniques and for handling of raw materials and digested residues. An energy systems analysis approach based on literature is applied to calculate the energy efficiency of biogas produced from biomass. Basically, the methodology is comprised of collecting data, proposing locations and estimating the energy input needed to produce biogas and output obtained from the generated biogas. The study showed that palm oil and municipal solid waste is two potential sources of biomass. The energy efficiency of biogas produced from palm oil residues and municipal solid wastes is 1.70 and 3.33 respectively. Municipal solid wastes have the higher energy efficiency due to less transportation distance and electricity consumption. Despite the inherent uncertainties in the calculations, it can be concluded that the energy potential to use biomass for biogas production is a promising alternative.

  7. Microbial biomass and activity in subsurface sediments from Vejen, Denmark

    DEFF Research Database (Denmark)

    Albrechtsen, Hans-Jørgen; Winding, Anne

    1992-01-01

    Subsurface sediment samples were collected from 4 to 31 m below landsurface in glacio-fluvial sediments from the Quaternary period. The samples were described in terms of pH, electrical conductivity, chloride concentration, organic matter content, and grain size distribution. Viable counts...... for mineralization of 14C-labelled compounds varied from 0.2 to 2.3 × 10−3 ml/(dpm · day) for acetate, and from 0 to 2.0 × 10−3 ml/(dpm · day) for phenol. Sediment texture influenced the total number of bacteria and potential for mineralization; with increasing content of clay and silt and decreasing content of sand...... a single abiotic parameter that could explain the variation of size and activity of the microbial population. The microbial data obtained in these geologically young sediments were compared to literature data from older sediments, and this comparison showed that age and type of geological formation might...

  8. Microbial Biodiesel Production by Direct Transesterification of Rhodotorula glutinis Biomass

    Directory of Open Access Journals (Sweden)

    I-Ching Kuan

    2018-04-01

    Full Text Available (1 Background: Lipids derived from oleaginous microbes have become promising alternative feedstocks for biodiesel. This is mainly because the lipid production rate from microbes is one to two orders of magnitude higher than those of energy crops. However, the conventional process for converting these lipids to biodiesel still requires a large amount of energy and organic solvents; (2 Methods: In this study, an oleaginous yeast, Rhodotorula glutinis, was used for direct transesterification without lipid pre-extraction to produce biodiesel, using sulfuric acid or sodium hydroxide as a catalyst. Such processes decreased the amount of energy and organic solvents required simultaneously; (3 Results: When 1 g of dry R. glutinis biomass was subject to direct transesterification in 20 mL of methanol catalyzed by 0.6 M H2SO4 at 70 °C for 20 h, the fatty acid methyl ester (FAME yield reached 111%. Using the same amount of biomass and methanol loading but catalyzed by 1 g/L NaOH at 70 °C for 10 h, the FAME yield reached 102%. The acid-catalyzed process showed a superior moisture tolerance; when the biomass contained 70% moisture, the FAME yield was 43% as opposed to 34% of the base-catalyzed counterpart; (4 Conclusions: Compared to conventional transesterification, which requires lipid pre-extraction, direct transesterification not only simplifies the process and shortens the reaction time, but also improves the FAME yield.

  9. Temporal variations in microbial biomass C and cellulolytic enzyme activity in arable soils: effects of organic matter input

    DEFF Research Database (Denmark)

    Debosz, K.; Rasmussen, Peter Have; Pedersen, A. R.

    1999-01-01

    Temporal variations in soil microbial biomass C concentration and in activity of extracellular enzymes of the cellulolytic complex were investigated in a field experiment after eight years of cultivation with either low organic matter input (low-OM) or high organic matter input (high-OM). The cul......Temporal variations in soil microbial biomass C concentration and in activity of extracellular enzymes of the cellulolytic complex were investigated in a field experiment after eight years of cultivation with either low organic matter input (low-OM) or high organic matter input (high......-OM). The cultivation systems differed in whether their source of fertiliser was mainly mineral or organic, in whether a winter cover crop was grown, and whether straw was mulched or removed. Sampling occurred at approximately monthly intervals, over a period of two years. Distinct temporal variations in microbial......) and an endocellulase activity of 44.2 +/- 1.1 nmol g(-1) h(-1). (C) 1999 Elsevier Science B.V. All rights reserved....

  10. Soil Microbial Biomass, Basal Respiration and Enzyme Activity of Main Forest Types in the Qinling Mountains

    Science.gov (United States)

    Cheng, Fei; Peng, Xiaobang; Zhao, Peng; Yuan, Jie; Zhong, Chonggao; Cheng, Yalong; Cui, Cui; Zhang, Shuoxin

    2013-01-01

    Different forest types exert essential impacts on soil physical-chemical characteristics by dominant tree species producing diverse litters and root exudates, thereby further regulating size and activity of soil microbial communities. However, the study accuracy is usually restricted by differences in climate, soil type and forest age. Our objective is to precisely quantify soil microbial biomass, basal respiration and enzyme activity of five natural secondary forest (NSF) types with the same stand age and soil type in a small climate region and to evaluate relationship between soil microbial and physical-chemical characters. We determined soil physical-chemical indices and used the chloroform fumigation-extraction method, alkali absorption method and titration or colorimetry to obtain the microbial data. Our results showed that soil physical-chemical characters remarkably differed among the NSFs. Microbial biomass carbon (Cmic) was the highest in wilson spruce soils, while microbial biomass nitrogen (Nmic) was the highest in sharptooth oak soils. Moreover, the highest basal respiration was found in the spruce soils, but mixed, Chinese pine and spruce stands exhibited a higher soil qCO2. The spruce soils had the highest Cmic/Nmic ratio, the greatest Nmic/TN and Cmic/Corg ratios were found in the oak soils. Additionally, the spruce soils had the maximum invertase activity and the minimum urease and catalase activities, but the maximum urease and catalase activities were found in the mixed stand. The Pearson correlation and principle component analyses revealed that the soils of spruce and oak stands obviously discriminated from other NSFs, whereas the others were similar. This suggested that the forest types affected soil microbial properties significantly due to differences in soil physical-chemical features. PMID:23840671

  11. Microbial biomass dynamics dominate N cycle responses to warming in a sub-arctic peatland

    Science.gov (United States)

    Weedon, J. T.; Aerts, R.; Kowalchuk, G. K.; van Bodegom, P. M.

    2012-04-01

    The balance of primary production and decomposition in sub-arctic peatlands may shift with climate change. Nitrogen availability will modulate this shift, but little is known about the drivers of soil nitrogen dynamics in these environments, and how they are influenced by rising soil temperatures. We used a long-term open top chamber warming experiment in Abisko, Sweden, to test for the interactive effects of spring warming, summer warming and winter snow addition on soil organic and inorganic nitrogen fluxes, potential activities of carbon and nitrogen cycle enzymes, and the structure of the soil-borne microbial communities. Summer warming increased the flux of soil organic nitrogen over the growing season, while simultaneously causing a seasonal decrease in microbial biomass, suggesting that N flux is driven by large late-season dieback of microbes. This change in N cycle dynamics was not reflected in any of the measured potential enzyme activities. Moreover, the soil microbial community structure was stable across treatments, suggesting non-specific microbial dieback. To further test whether the observed patterns were driven by direct temperature effects or indirect effects (via microbial biomass dynamics), we conducted follow-up controlled experiments in soil mesocosms. Experimental additions of dead microbial cells had stronger effects on N pool sizes and enzyme activities than either plant litter addition or a 5 °C alteration in incubation temperatures. Peat respiration was positively affected by both substrate addition and higher incubation temperatures, but the temperature-only effect was not sufficient to account for the increases in respiration observed in previous field experiments. We conclude that warming effects on peatland N cycling (and to some extent C cycling) are dominated by indirect effects, acting through alterations to the seasonal flux of microbe-derived organic matter. We propose that climate change models of soil carbon and nitrogen

  12. Influence of diligent disintegration on anaerobic biomass and performance of microbial fuel cell.

    Science.gov (United States)

    Divyalakshmi, Palanisamy; Murugan, Devaraj; Rai, Chockalingam Lajapathi

    2017-12-01

    To enhance the performance of microbial fuel cells (MFC) by increasing the surface area of cathode and diligent mechanical disintegration of anaerobic biomass. Tannery effluent and anaerobic biomass were used. The increase in surface area of the cathode resulted in 78% COD removal, with the potential, current density, power density and coulombic efficiency of 675 mV, 147 mA m -2 , 33 mW m -2 and 3.5%, respectively. The work coupled with increased surface area of the cathode with diligent mechanical disintegration of the biomass, led to a further increase in COD removal of 82% with the potential, current density, power density and coulombic efficiency of 748 mV, 229 mA m -2 , 78 mW m -2 and 6% respectively. Mechanical disintegration of the biomass along with increased surface area of cathode enhances power generation in vertical MFC reactors using tannery effluent as fuel.

  13. Annual Removal of Aboveground Plant Biomass Alters Soil Microbial Responses to Warming

    Directory of Open Access Journals (Sweden)

    Kai Xue

    2016-09-01

    Full Text Available Clipping (i.e., harvesting aboveground plant biomass is common in agriculture and for bioenergy production. However, microbial responses to clipping in the context of climate warming are poorly understood. We investigated the interactive effects of grassland warming and clipping on soil properties and plant and microbial communities, in particular, on microbial functional genes. Clipping alone did not change the plant biomass production, but warming and clipping combined increased the C4 peak biomass by 47% and belowground net primary production by 110%. Clipping alone and in combination with warming decreased the soil carbon input from litter by 81% and 75%, respectively. With less carbon input, the abundances of genes involved in degrading relatively recalcitrant carbon increased by 38% to 137% in response to either clipping or the combined treatment, which could weaken long-term soil carbon stability and trigger positive feedback with respect to warming. Clipping alone also increased the abundance of genes for nitrogen fixation, mineralization, and denitrification by 32% to 39%. Such potentially stimulated nitrogen fixation could help compensate for the 20% decline in soil ammonium levels caused by clipping alone and could contribute to unchanged plant biomass levels. Moreover, clipping tended to interact antagonistically with warming, especially with respect to effects on nitrogen cycling genes, demonstrating that single-factor studies cannot predict multifactorial changes. These results revealed that clipping alone or in combination with warming altered soil and plant properties as well as the abundance and structure of soil microbial functional genes. Aboveground biomass removal for biofuel production needs to be reconsidered, as the long-term soil carbon stability may be weakened.

  14. Bentonite. Geotechnical barrier and source for microbial life

    Energy Technology Data Exchange (ETDEWEB)

    Matschiavelli, Nicole; Kluge, Sindy; Cherkouk, Andrea [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). HZDR Young Investigator Group; Steglich, Jennifer

    2017-06-01

    Due to their properties, namely a high swelling capacity and a low hydraulic conductivity, Bentonites fulfil as geotechnical barrier a sealing and buffering function in the nuclear waste repository. Depending on the mineral composition Bentonites contain many suitable electron-donors and -acceptors, enabling potential microbial life. For the potential repository of highly radioactive waste the microbial mediated transformation of Bentonite could influence its properties as a barrier material. Microcosms were set up containing Bentonite and anaerobic synthetic Opalinus-clay-pore water solution under an N{sub 2}/CO{sub 2}-atmosphere to elucidate the microbial potential within selected Bentonites. Substrates like acetate and lactate were supplemented to stimulate potential microbial activity. First results show that bentonites represent a source for microbial life, demonstrated by the consumption of lactate and the formation of pyruvate. Furthermore, microbial iron-reduction was determined, which plays a crucial role in Betonite-transformation.

  15. Bentonite. Geotechnical barrier and source for microbial life

    International Nuclear Information System (INIS)

    Matschiavelli, Nicole; Kluge, Sindy; Cherkouk, Andrea; Steglich, Jennifer

    2017-01-01

    Due to their properties, namely a high swelling capacity and a low hydraulic conductivity, Bentonites fulfil as geotechnical barrier a sealing and buffering function in the nuclear waste repository. Depending on the mineral composition Bentonites contain many suitable electron-donors and -acceptors, enabling potential microbial life. For the potential repository of highly radioactive waste the microbial mediated transformation of Bentonite could influence its properties as a barrier material. Microcosms were set up containing Bentonite and anaerobic synthetic Opalinus-clay-pore water solution under an N_2/CO_2-atmosphere to elucidate the microbial potential within selected Bentonites. Substrates like acetate and lactate were supplemented to stimulate potential microbial activity. First results show that bentonites represent a source for microbial life, demonstrated by the consumption of lactate and the formation of pyruvate. Furthermore, microbial iron-reduction was determined, which plays a crucial role in Betonite-transformation.

  16. New paradigms for Salmonella source attribution based on microbial subtyping.

    NARCIS (Netherlands)

    Mughini-Gras, Lapo; Franz, Eelco; van Pelt, Wilfrid

    Microbial subtyping is the most common approach for Salmonella source attribution. Typically, attributions are computed using frequency-matching models like the Dutch and Danish models based on phenotyping data (serotyping, phage-typing, and antimicrobial resistance profiling). Herewith, we

  17. Taxonomic and Functional Responses of Soil Microbial Communities to Annual Removal of Aboveground Plant Biomass

    Science.gov (United States)

    Guo, Xue; Zhou, Xishu; Hale, Lauren; Yuan, Mengting; Feng, Jiajie; Ning, Daliang; Shi, Zhou; Qin, Yujia; Liu, Feifei; Wu, Liyou; He, Zhili; Van Nostrand, Joy D.; Liu, Xueduan; Luo, Yiqi; Tiedje, James M.; Zhou, Jizhong

    2018-01-01

    Clipping, removal of aboveground plant biomass, is an important issue in grassland ecology. However, few studies have focused on the effect of clipping on belowground microbial communities. Using integrated metagenomic technologies, we examined the taxonomic and functional responses of soil microbial communities to annual clipping (2010–2014) in a grassland ecosystem of the Great Plains of North America. Our results indicated that clipping significantly (P microbial respiration rates. Annual temporal variation within the microbial communities was much greater than the significant changes introduced by clipping, but cumulative effects of clipping were still observed in the long-term scale. The abundances of some bacterial and fungal lineages including Actinobacteria and Bacteroidetes were significantly (P microbial communities were significantly correlated with soil respiration and plant productivity. Intriguingly, clipping effects on microbial function may be highly regulated by precipitation at the interannual scale. Altogether, our results illustrated the potential of soil microbial communities for increased soil organic matter decomposition under clipping land-use practices. PMID:29904372

  18. Microbial source tracking: a tool for identifying sources of microbial contamination in the food chain.

    Science.gov (United States)

    Fu, Ling-Lin; Li, Jian-Rong

    2014-01-01

    The ability to trace fecal indicators and food-borne pathogens to the point of origin has major ramifications for food industry, food regulatory agencies, and public health. Such information would enable food producers and processors to better understand sources of contamination and thereby take corrective actions to prevent transmission. Microbial source tracking (MST), which currently is largely focused on determining sources of fecal contamination in waterways, is also providing the scientific community tools for tracking both fecal bacteria and food-borne pathogens contamination in the food chain. Approaches to MST are commonly classified as library-dependent methods (LDMs) or library-independent methods (LIMs). These tools will have widespread applications, including the use for regulatory compliance, pollution remediation, and risk assessment. These tools will reduce the incidence of illness associated with food and water. Our aim in this review is to highlight the use of molecular MST methods in application to understanding the source and transmission of food-borne pathogens. Moreover, the future directions of MST research are also discussed.

  19. A survey of Opportunities for Microbial Conversion of Biomass to Hydrocarbon Compatible Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Jovanovic, Iva; Jones, Susanne B.; Santosa, Daniel M.; Dai, Ziyu; Ramasamy, Karthikeyan K.; Zhu, Yunhua

    2010-09-01

    Biomass is uniquely able to supply renewable and sustainable liquid transportation fuels. In the near term, the Biomass program has a 2012 goal of cost competitive cellulosic ethanol. However, beyond 2012, there will be an increasing need to provide liquid transportation fuels that are more compatible with the existing infrastructure and can supply fuel into all transportation sectors, including aviation and heavy road transport. Microbial organisms are capable of producing a wide variety of fuel and fuel precursors such as higher alcohols, ethers, esters, fatty acids, alkenes and alkanes. This report surveys liquid fuels and fuel precurors that can be produced from microbial processes, but are not yet ready for commercialization using cellulosic feedstocks. Organisms, current research and commercial activities, and economics are addressed. Significant improvements to yields and process intensification are needed to make these routes economic. Specifically, high productivity, titer and efficient conversion are the key factors for success.

  20. Biomass production and energy source of thermophiles in a Japanese alkaline geothermal pool.

    Science.gov (United States)

    Kimura, Hiroyuki; Mori, Kousuke; Nashimoto, Hiroaki; Hattori, Shohei; Yamada, Keita; Koba, Keisuke; Yoshida, Naohiro; Kato, Kenji

    2010-02-01

    Microbial biomass production has been measured to investigate the contribution of planktonic bacteria to fluxations in dissolved organic matter in marine and freshwater environments, but little is known about biomass production of thermophiles inhabiting geothermal and hydrothermal regions. The biomass production of thermophiles inhabiting an 85 degrees C geothermal pool was measured by in situ cultivation using diffusion chambers. The thermophiles' growth rates ranged from 0.43 to 0.82 day(-1), similar to those of planktonic bacteria in marine and freshwater habitats. Biomass production was estimated based on cellular carbon content measured directly from the thermophiles inhabiting the geothermal pool, which ranged from 5.0 to 6.1 microg C l(-1) h(-1). This production was 2-75 times higher than that of planktonic bacteria in other habitats, because the cellular carbon content of the thermophiles was much higher. Quantitative PCR and phylogenetic analysis targeting 16S rRNA genes revealed that thermophilic H2-oxidizing bacteria closely related to Calderobacterium and Geothermobacterium were dominant in the geothermal pool. Chemical analysis showed the presence of H2 in gases bubbling from the bottom of the geothermal pool. These results strongly suggested that H2 plays an important role as a primary energy source of thermophiles in the geothermal pool.

  1. Dynamic relationships between microbial biomass, respiration, inorganic nutrients and enzyme activities: informing enzyme based decomposition models

    Directory of Open Access Journals (Sweden)

    Daryl L Moorhead

    2013-08-01

    Full Text Available We re-examined data from a recent litter decay study to determine if additional insights could be gained to inform decomposition modeling. Rinkes et al. (2013 conducted 14-day laboratory incubations of sugar maple (Acer saccharum or white oak (Quercus alba leaves, mixed with sand (0.4% organic C content or loam (4.1% organic C. They measured microbial biomass C, carbon dioxide efflux, soil ammonium, nitrate, and phosphate concentrations, and β-glucosidase (BG, β-N-acetyl-glucosaminidase (NAG, and acid phosphatase (AP activities on days 1, 3, and 14. Analyses of relationships among variables yielded different insights than original analyses of individual variables. For example, although respiration rates per g soil were higher for loam than sand, rates per g soil C were actually higher for sand than loam, and rates per g microbial C showed little difference between treatments. Microbial biomass C peaked on day 3 when biomass-specific activities of enzymes were lowest, suggesting uptake of litter C without extracellular hydrolysis. This result refuted a common model assumption that all enzyme production is constitutive and thus proportional to biomass, and/or indicated that part of litter decay is independent of enzyme activity. The length and angle of vectors defined by ratios of enzyme activities (BG/NAG versus BG/AP represent relative microbial investments in C (length, and N and P (angle acquiring enzymes. Shorter lengths on day 3 suggested low C limitation, whereas greater lengths on day 14 suggested an increase in C limitation with decay. The soils and litter in this study generally had stronger P limitation (angles > 45˚. Reductions in vector angles to < 45˚ for sand by day 14 suggested a shift to N limitation. These relational variables inform enzyme-based models, and are usually much less ambiguous when obtained from a single study in which measurements were made on the same samples than when extrapolated from separate studies.

  2. Understory biomass from southern pine forests as a fuel source

    Energy Technology Data Exchange (ETDEWEB)

    Ku, T.T. [Univ. of Arkansas, Monticello, AR (United States); Baker, J.B. [USDA Forest Service, Monticello, AR (United States)

    1993-12-31

    The energy crisis in the US in the late 1970s led to accelerated research on renewable energy resources. The use of woody biomass, harvested from pine forests in the southern US, as a renewable energy source would not only provide an efficient energy alternative to forest industries, but its use would also reduce understory competition and accelerate growth of overstory crop trees. This study was initiated in the early 1980s to investigate the feasibility and applicability of the use of understory vegetation as a possible energy fuel resource. All woody understory vegetation [<14 cm (<5.5 in) in dbh], on 0.2 ha (0.5 ac) plots that represented a range of stand/site conditions of pine stands located in twelve southern Arkansas counties and two northern Louisiana parishes were characterized, quantified, and harvested. Based on the biomass yield from 720 subplots nested within 40 main plots, the top five dominant species in the understory, based on number and size were: Red maple, red oaks, pines, sweetgum, and winged elm. Some other species occurring, but in smaller proportions, were flowering dogwood, beautyberry, white oaks, black gum, wax myrtle, hickories, persimmon, and ashes. Most of these species are deciduous hardwoods that provide high BTU output upon burning. The average yield of chipped understory biomass was 23.5 T/ha with no difference occurring between summer and winter harvests. A predictive model of understory biomass production was developed using a step-wise multivariate regression analysis. In relation to forest type, high density pine stands produced 53% more understory biomass than high density pine-hardwood stands. The average moisture content of biomass was significantly lower when harvested in winter than when harvested in summer.

  3. Long-term effects of aided phytostabilisation of trace elements on microbial biomass and activity, enzyme activities, and composition of microbial community in the Jales contaminated mine spoils

    Energy Technology Data Exchange (ETDEWEB)

    Renella, Giancarlo [Department of Soil Science and Plant Nutrition, University of Florence, Piazzale delle Cascine 28, I-50144 Florence (Italy)], E-mail: giancarlo.renella@unifi.it; Landi, Loretta; Ascher, Judith; Ceccherini, Maria Teresa; Pietramellara, Giacomo; Mench, Michel; Nannipieri, Paolo [Department of Soil Science and Plant Nutrition, University of Florence, Piazzale delle Cascine 28, I-50144 Florence (Italy)

    2008-04-15

    We studied the effectiveness of remediation on microbial endpoints, namely microbial biomass and activity, microbial and plant species richness, of an As-contaminated mine spoil, amended with compost (C) alone and in combination with beringite (B) or zerovalent iron grit (Z), to increase organic matter content and reduce trace elements mobility, and to allow Holcus lanatus and Pinus pinaster growth. Untreated spoil showed the lowest microbial biomass and activity and hydrolase activities, and H. lanatus as sole plant species, whereas the presented aided phytostabilisation option, especially CBZ treatment, significantly increased microbial biomass and activity and allowed colonisation by several plant species, comparable to those of an uncontaminated sandy soil. Microbial species richness was only increased in spoils amended with C alone. No clear correlation occurred between trace element mobility and microbial parameters and plant species richness. Our results indicate that the choice of indicators of soil remediation practices is a bottleneck. - Organo-mineral amendment and revegetation of a gold mine spoil increased microbial activity but did not increase microbial species richness.

  4. Long-term effects of aided phytostabilisation of trace elements on microbial biomass and activity, enzyme activities, and composition of microbial community in the Jales contaminated mine spoils

    International Nuclear Information System (INIS)

    Renella, Giancarlo; Landi, Loretta; Ascher, Judith; Ceccherini, Maria Teresa; Pietramellara, Giacomo; Mench, Michel; Nannipieri, Paolo

    2008-01-01

    We studied the effectiveness of remediation on microbial endpoints, namely microbial biomass and activity, microbial and plant species richness, of an As-contaminated mine spoil, amended with compost (C) alone and in combination with beringite (B) or zerovalent iron grit (Z), to increase organic matter content and reduce trace elements mobility, and to allow Holcus lanatus and Pinus pinaster growth. Untreated spoil showed the lowest microbial biomass and activity and hydrolase activities, and H. lanatus as sole plant species, whereas the presented aided phytostabilisation option, especially CBZ treatment, significantly increased microbial biomass and activity and allowed colonisation by several plant species, comparable to those of an uncontaminated sandy soil. Microbial species richness was only increased in spoils amended with C alone. No clear correlation occurred between trace element mobility and microbial parameters and plant species richness. Our results indicate that the choice of indicators of soil remediation practices is a bottleneck. - Organo-mineral amendment and revegetation of a gold mine spoil increased microbial activity but did not increase microbial species richness

  5. Effects of elevated nitrogen deposition on soil microbial biomass carbon in major subtropical forests of southern China

    Institute of Scientific and Technical Information of China (English)

    Hui WANG; Jiangming MO; Xiankai LU; Jinghua XUE; Jiong LI; Yunting FANG

    2009-01-01

    The effects of elevated nitrogen deposition on soil microbial biomass carbon (C) and extractable dissolved organic carbon (DOC) in three types of forest of southern China were studied in November, 2004 and June, 2006. Plots were established in a pine forest (PF), a mixed pine and broad-leaved forest (MF) and monsoon evergreen broad-leaved forest (MEBF) in the Dinghushan Nature Reserve. Nitrogen treatments included a control (no N addition), low N (50 kg N/(hm2.a)), medium N (100 kg N/ (hm2. a)) and high N (150 kg N/(hm2. a)). Microbial biomass C and extractable DOC were determined using a chloro-form fumigation-extraction method. Results indicate that microbial biomass C and extractable DOC were higher in June, 2006 than in November, 2004 and higher in the MEBF than in the PF or the MF. The response of soil microbial biomass C and extractable DOC to nitrogen deposition varied depending on the forest type and the level of nitrogen treatment. In the PF or MF forests, no significantly different effects of nitrogen addition were found on soil microbial biomass C and extractable DOC. In the MEBF, however, the soil microbial biomass C generally decreased with increased nitrogen levels and high nitrogen addition significantly reduced soil microbial biomass C. The response of soil extractable DOC to added nitrogen in the MEBF shows the opposite trend to soil microbial biomass C. These results suggest that nitrogen deposition may increase the accumulation of soil organic carbon in the MEBF in the study region.

  6. The Microbial DNA Index System (MiDIS): A tool for microbial pathogen source identification

    Energy Technology Data Exchange (ETDEWEB)

    Velsko, S. P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2010-08-09

    The microbial DNA Index System (MiDIS) is a concept for a microbial forensic database and investigative decision support system that can be used to help investigators identify the sources of microbial agents that have been used in a criminal or terrorist incident. The heart of the proposed system is a rigorous method for calculating source probabilities by using certain fundamental sampling distributions associated with the propagation and mutation of microbes on disease transmission networks. This formalism has a close relationship to mitochondrial and Y-chromosomal human DNA forensics, and the proposed decision support system is somewhat analogous to the CODIS and SWGDAM mtDNA databases. The MiDIS concept does not involve the use of opportunistic collections of microbial isolates and phylogenetic tree building as a basis for inference. A staged approach can be used to build MiDIS as an enduring capability, beginning with a pilot demonstration program that must meet user expectations for performance and validation before evolving into a continuing effort. Because MiDIS requires input from a a broad array of expertise including outbreak surveillance, field microbial isolate collection, microbial genome sequencing, disease transmission networks, and laboratory mutation rate studies, it will be necessary to assemble a national multi-laboratory team to develop such a system. The MiDIS effort would lend direction and focus to the national microbial genetics research program for microbial forensics, and would provide an appropriate forensic framework for interfacing to future national and international disease surveillance efforts.

  7. Microbial biomass and activity in litter during the initial development of pure and mixed plantations of Eucalyptus grandis and Acacia mangium

    Directory of Open Access Journals (Sweden)

    Daniel Bini

    2013-02-01

    Full Text Available Studies on microbial activity and biomass in forestry plantations often overlook the role of litter, typically focusing instead on soil nutrient contents to explain plant and microorganism development. However, since the litter is a significant source of recycled nutrients that affect nutrient dynamics in the soil, litter composition may be more strongly correlated with forest growth and development than soil nutrient contents. This study aimed to test this hypothesis by examining correlations between soil C, N, and P; litter C, N, P, lignin content, and polyphenol content; and microbial biomass and activity in pure and mixed second-rotation plantations of Eucalyptus grandis and Acacia mangium before and after senescent leaf drop. The numbers of cultivable fungi and bacteria were also estimated. All properties were correlated with litter C, N, P, lignin and polyphenols, and with soil C and N. We found higher microbial activity (CO2 evolution in litter than in soil. In the E. grandis monoculture before senescent leaf drop, microbial biomass C was 46 % higher in litter than in soil. After leaf drop, this difference decreased to 16 %. In A. mangium plantations, however, microbial biomass C was lower in litter than in soil both before and after leaf drop. Microbial biomass N of litter was approximately 94 % greater than that of the soil in summer and winter in all plantations. The number of cultivable fungi and bacteria increased after leaf drop, especially so in the litter. Fungi were also more abundant in the E. grandis litter. In general, the A. mangium monoculture was associated with higher levels of litter lignin and N, especially after leaf drop. In contrast, the polyphenol and C levels in E. grandis monoculture litter were higher after leaf drop. These properties were negatively correlated with total soil C and N. Litter in the mixed stands had lower C:N and C:P ratios and higher N, P, and C levels in the microbial biomass. This suggests more

  8. Continuous exposure of pesticides in an aquifer changes microbial biomass, diversity and degradation potential

    DEFF Research Database (Denmark)

    de Lipthay, J. R.; Johnsen, K.; Aamand, J.

    2000-01-01

    We studied in situ effects of pesticide exposure on microbial degradation potential and community structure of aquifer sediments. Sediment samples pre-exposed to pesticides were significantly different to non-exposed control samples. Pre-exposed sediment showed an increased degradation potential ...... towards phenoxyalcanoic acid herbicides as well as impact on microbial diversity was observed. Furthermore, bacterial biomass was changed, e.g. increased numbers of phenoxyalcanoic acid degraders in pesticide exposed sediment.......We studied in situ effects of pesticide exposure on microbial degradation potential and community structure of aquifer sediments. Sediment samples pre-exposed to pesticides were significantly different to non-exposed control samples. Pre-exposed sediment showed an increased degradation potential...

  9. Analysis of Low-Biomass Microbial Communities in the Deep Biosphere.

    Science.gov (United States)

    Morono, Y; Inagaki, F

    2016-01-01

    Over the past few decades, the subseafloor biosphere has been explored by scientific ocean drilling to depths of about 2.5km below the seafloor. Although organic-rich anaerobic sedimentary habitats in the ocean margins harbor large numbers of microbial cells, microbial populations in ultraoligotrophic aerobic sedimentary habitats in the open ocean gyres are several orders of magnitude less abundant. Despite advances in cultivation-independent molecular ecological techniques, exploring the low-biomass environment remains technologically challenging, especially in the deep subseafloor biosphere. Reviewing the historical background of deep-biosphere analytical methods, the importance of obtaining clean samples and tracing contamination, as well as methods for detecting microbial life, technological aspects of molecular microbiology, and detecting subseafloor metabolic activity will be discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Earthworms facilitate the stabilization of pelletized dewatered sludge through shaping microbial biomass and activity and community.

    Science.gov (United States)

    Fu, Xiaoyong; Cui, Guangyu; Huang, Kui; Chen, Xuemin; Li, Fusheng; Zhang, Xiaoyu; Li, Fei

    2016-03-01

    In this study, the effect of earthworms on microbial features during vermicomposting of pelletized dewatered sludge (PDS) was investigated through comparing two degradation systems with and without earthworm E isenia fetida involvement. After 60 days of experimentation, a relatively stable product with low organic matter and high nitrate and phosphorous was harvested when the earthworms were involved. During the process, earthworms could enhance microbial activity and biomass at the initial stage and thus accelerating the rapid decomposition of PDS. The end products of vermicomposting allowed the lower values of bacterial and eukaryotic densities comparison with those of no earthworm addition. In addition, the presence of earthworms modified the bacterial and fungal diversity, making the disappearances of some pathogens and specific decomposing bacteria of recalcitrant substrates in the vermicomposting process. This study evidences that earthworms can facilitate the stabilization of PDS through modifying microbial activity and number and community during vermicomposting.

  11. Effect of buctril super (Bromoxynil herbicide on soil microbial biomass and bacterial population

    Directory of Open Access Journals (Sweden)

    Zafar Abbas

    2014-02-01

    Full Text Available The present study aimed to evaluate the effect of bromoxynil herbicide on soil microorganisms, with the hypothesis that this herbicide caused suppression in microbial activity and biomass by exerting toxic effect on them. Nine sites of Punjab province (Pakistan those had been exposed to bromoxynil herbicide for about last ten years designated as soil 'A' were surveyed in 2011 and samples were collected and analyzed for Microbial Biomass Carbon (MBC, Biomass Nitrogen (MBN, Biomass Phosphorus (MBP and bacterial population. Simultaneously, soil samples from the same areas those were not exposed to herbicide designated as soil 'B' were taken. At all the sites MBC, MBN and MBP ranged from 131 to 457, 1.22 to 13.1 and 0.59 to 3.70 µg g-1 in the contaminated soils (Soil A, which was 187 to 573, 1.70 to 14.4 and 0.72 to 4.12 µg g-1 in the soils without contamination (soil B. Bacterial population ranged from 0.67 to 1.84x10(8 and 0.87 to 2.37x10(8 cfu g-1 soil in the soils A and B, respectively. Bromoxynil residues ranged from 0.09 to 0.24 mg kg-1 at all the sites in soil A. But no residues were detected in the soil B. Due to lethal effect of bromoxynil residues on the above parameters, considerable decline in these parameters was observed in the contaminated soils. Results depicted that the herbicide had left toxic effects on soil microbial parameters, thus confirmed that continuous use of this herbicide affected the quality of soil and sustainable crop production.

  12. The effect of D123 wheat as a companion crop on soil enzyme activities, microbial biomass and microbial communities in the rhizosphere of watermelon.

    Science.gov (United States)

    Xu, Weihui; Wang, Zhigang; Wu, Fengzhi

    2015-01-01

    The growth of watermelon is often threatened by Fusarium oxysporum f. sp. niveum (Fon) in successively monocultured soil, which results in economic loss. The objective of this study was to investigate the effect of D123 wheat as a companion crop on soil enzyme activities, microbial biomass and microbial communities in the rhizosphere of watermelon and to explore the relationship between the effect and the incidence of wilt caused by Fon. The results showed that the activities of soil polyphenol oxidase, urease and invertase were increased, the microbial biomass nitrogen (MBN) and microbial biomass phosphorus (MBP) were significantly increased, and the ratio of MBC/MBN was decreased (P Fusarium wilt was also decreased in the watermelon/wheat companion system. In conclusion, this study indicated that D123 wheat as a companion crop increased soil enzyme activities and microbial biomass, decreased the Fon population, and changed the relative abundance of microbial communities in the rhizosphere of watermelon, which may be related to the reduction of Fusarium wilt in the watermelon/wheat companion system.

  13. Biomass assessment of microbial surface communities by means of hyperspectral remote sensing data.

    Science.gov (United States)

    Rodríguez-Caballero, Emilio; Paul, Max; Tamm, Alexandra; Caesar, Jennifer; Büdel, Burkhard; Escribano, Paula; Hill, Joachim; Weber, Bettina

    2017-05-15

    Dryland vegetation developed morphological and physiological strategies to cope with drought. However, as aridity increases, vascular plant coverage gets sparse and microbially-dominated surface communities (MSC), comprising cyanobacteria, algae, lichens and bryophytes together with heterotropic bacteria, archaea and fungi, gain relevance. Nevertheless, the relevance of MSC net primary productivity has only rarely been considered in ecosystem scale studies, and detailed information on their contribution to the total photosynthetic biomass reservoir is largely missing. In this study, we mapped the spatial distribution of two different MSC (biological soil crusts and quartz fields hosting hypolithic crusts) at two different sites within the South African Succulent Karoo (Soebatsfontein and Knersvlakte). Then we characterized both types of MSC in terms of chlorophyll content, and combining these data with the biocrust and quartz field maps, we estimated total biomass values of MSCs and their spatial patterns within the two different ecosystems. Our results revealed that MSC are important vegetation components of the South African Karoo biome, revealing clear differences between the two sites. At Soebatsfontein, MSC occurred as biological soil crusts (biocrusts), which covered about one third of the landscape reaching an overall biomass value of ~480gha -1 of chlorophyll a+b at the landscape scale. In the Knersvlakte, which is characterized by harsher environmental conditions (i.e. higher solar radiation and potential evapotranspiration), MSC occurred as biocrusts, but also formed hypolithic crusts growing on the lower soil-immersed parts of translucent quartz pebbles. Whereas chlorophyll concentrations of biocrusts and hypolithic crusts where insignificantly lower in the Knersvlakte, the overall MSC biomass reservoir was by far larger with ~780gha -1 of chlorophyll a+b. Thus, the complementary microbially-dominated surface communities promoted biomass formation within

  14. Looking inside the box: using Raman microspectroscopy to deconstruct microbial biomass stoichiometry one cell at a time

    Science.gov (United States)

    Hall, Edward K.; Singer, Gabriel A.; Pölzl, Marvin; Hämmerle, Ieda; Schwarz, Christian; Daims, Holger; Maixner, Frank; Battin, Tom J.

    2011-01-01

    Stoichiometry of microbial biomass is a key determinant of nutrient recycling in a wide variety of ecosystems. However, little is known about the underlying causes of variance in microbial biomass stoichiometry. This is primarily because of technological constraints limiting the analysis of macromolecular composition to large quantities of microbial biomass. Here, we use Raman microspectroscopy (MS), to analyze the macromolecular composition of single cells of two species of bacteria grown on minimal media over a wide range of resource stoichiometry. We show that macromolecular composition, determined from a subset of identified peaks within the Raman spectra, was consistent with macromolecular composition determined using traditional analytical methods. In addition, macromolecular composition determined by Raman MS correlated with total biomass stoichiometry, indicating that analysis with Raman MS included a large proportion of a cell's total macromolecular composition. Growth phase (logarithmic or stationary), resource stoichiometry and species identity each influenced each organism's macromolecular composition and thus biomass stoichiometry. Interestingly, the least variable peaks in the Raman spectra were those responsible for differentiation between species, suggesting a phylogenetically specific cellular architecture. As Raman MS has been previously shown to be applicable to cells sampled directly from complex environments, our results suggest Raman MS is an extremely useful application for evaluating the biomass stoichiometry of environmental microorganisms. This includes the ability to partition microbial biomass into its constituent macromolecules and increase our understanding of how microorganisms in the environment respond to resource heterogeneity.

  15. The ecological effects of different loading rates of metalaxyl on microbial biomass in unplanted and planted soils under field conditions

    Directory of Open Access Journals (Sweden)

    M. Mansourzadeh

    2016-05-01

    Full Text Available Fungicides are most widely used pesticides in Iran and the world. Application of fungicides may affect the populations and activity of soil microorganisms, particularly fungi, with a consequence for soil fertility and crop growth. In the current study, the effects of different levels of metalaxyl on soil microbial biomass carbon (C and nitrogen (N, microbial biomass C/N ratio and metabolic quotient under field conditions were assessed. Two levels of metalaxyl (30 and 60 kg.ha-1 were applied in planted soils with corn and unplanted calcareous soils, using a split-plots experiment in a completely randomized design with three replications. The C and N contents in soil microbial biomass as well as metabolic quotient were measured at 30 and 90 days after the onset of the experiment. Results showed that in cultivated soils metalaxyl application at 30 kg.ha-1 increased (15-80% significantly (p≤0.01 the amounts of microbial biomass C and N at both intervals (except microbial biomass C at 90 days compared to the control soil (0 kg.ha-1, while in uncultivated soils both microbial biomass C and N reduced by almost 1-34%. Microbial biomass C/N ratios in unplanted soils decreased (15 and 53% with increasing loading rates of metalaxyl, without a clear effect in cultivated soils. On the other hand, metabolic quotient values reduced (48% at 30 and 60 kg.ha-1 metalaxyl in corn-cultivated soils when compared to untreated soils while in uncultivated soils metalaxyl rate at 30 kg.a-1 had the greatest values at 30 days, and increased with increasing the levels of metalaxyl at 90 days. In summary, application of metalaxyl can either reduce or increase soil biological indices, and the direction and changes are depended upon the application rate of metalaxyl, time elapsed since metalaxyl application and the presence or absence of plant.

  16. Microbial Production of Malic Acid from Biofuel-Related Coproducts and Biomass

    Directory of Open Access Journals (Sweden)

    Thomas P. West

    2017-04-01

    Full Text Available The dicarboxylic acid malic acid synthesized as part of the tricarboxylic acid cycle can be produced in excess by certain microorganisms. Although malic acid is produced industrially to a lesser extent than citric acid, malic acid has industrial applications in foods and pharmaceuticals as an acidulant among other uses. Only recently has the production of this organic acid from coproducts of industrial bioprocessing been investigated. It has been shown that malic acid can be synthesized by microbes from coproducts generated during biofuel production. More specifically, malic acid has been shown to be synthesized by species of the fungus Aspergillus on thin stillage, a coproduct from corn-based ethanol production, and on crude glycerol, a coproduct from biodiesel production. In addition, the fungus Ustilago trichophora has also been shown to produce malic acid from crude glycerol. With respect to bacteria, a strain of the thermophilic actinobacterium Thermobifida fusca has been shown to produce malic acid from cellulose and treated lignocellulosic biomass. An alternate method of producing malic acid is to use agricultural biomass converted to syngas or biooil as a substrate for fungal bioconversion. Production of poly(β-l-malic acid by strains of Aureobasidium pullulans from agricultural biomass has been reported where the polymalic acid is subsequently hydrolyzed to malic acid. This review examines applications of malic acid, metabolic pathways that synthesize malic acid and microbial malic acid production from biofuel-related coproducts, lignocellulosic biomass and poly(β-l-malic acid.

  17. Optimization studies for the bioconversion of Jerusalem artichoke tubers to ethanol and microbial biomass

    Energy Technology Data Exchange (ETDEWEB)

    Margaritis, A.; Bajpai, P.; Cannell, E.

    1981-01-01

    A total of 8 yeast and other microbial cultures were grown in the extract derived from the tubers of Jerusalem artichoke (Helianthus tuberosus) and screened according to the following optimization criteria: rates and yields of ethanol production, rates and yields of biomass production, and percent of original sugars utilized during fermentation. Batch growth kinetic parameters were also determined for the cultures studied. Kluyveromyces marxianus UCD (FST) 55-82 had the highest specific growth rate, 0.41/h, with a high ethanol yield, 88% of theoretical.

  18. The effect of D123 wheat as a companion crop on soil enzyme activities, microbial biomass and microbial communities in the rhizosphere of watermelon

    Directory of Open Access Journals (Sweden)

    Wei Hui Xu

    2015-09-01

    Full Text Available The growth of watermelon is often threatened by Fusarium oxysporum f. sp. niveum (Fon in successively monocultured soil, which results in economic loss. The objective of this study was to investigate the effect of D123 wheat as a companion crop on soil enzyme activities, microbial biomass and microbial communities in the rhizosphere of watermelon and to explore the relationship between the effect and the incidence of wilt caused by Fon. The results showed that the activities of soil polyphenol oxidase, urease and invertase were increased, the microbial biomass nitrogen (MBN and microbial biomass phosphorus (MBP were significantly increased, and the ratio of MBC/MBN was decreased (P<0.05. Real-time PCR analysis showed that the Fon population declined significantly in the watermelon/wheat companion system compared with the monoculture system (P<0.05. The analysis of microbial communities showed that the relative abundance of microbial communities was changed in the rhizosphere of watermelon. Compared with the monoculture system, the relative abundances of Alphaproteobacteria, Actinobacteria, Gemmatimonadetes and Sordariomycetes were increased, and the relative abundances of Gammaproteobacteria, Sphingobacteria, Cytophagia, Pezizomycetes, and Eurotiomycetes were decreased in the rhizosphere of watermelon in the watermelon/wheat companion system; importantly, the incidence of Fusarium wilt was also decreased in the watermelon/wheat companion system. In conclusion, this study indicated that D123 wheat as a companion crop increased soil enzyme activities and microbial biomass, decreased the Fon population, and changed the relative abundance of microbial communities in the rhizosphere of watermelon, which may be related to the reduction of Fusarium wilt in the watermelon/wheat companion system.

  19. Effects of Biochar on Soil Microbial Biomass after Four Years of Consecutive Application in the North China Plain

    Science.gov (United States)

    Zhang, Qing-zhong; Dijkstra, Feike A.; Liu, Xing-ren; Wang, Yi-ding; Huang, Jian; Lu, Ning

    2014-01-01

    The long term effect of biochar application on soil microbial biomass is not well understood. We measured soil microbial biomass carbon (MBC) and nitrogen (MBN) in a field experiment during a winter wheat growing season after four consecutive years of no (CK), 4.5 (B4.5) and 9.0 t biochar ha−1 yr−1 (B9.0) applied. For comparison, a treatment with wheat straw residue incorporation (SR) was also included. Results showed that biochar application increased soil MBC significantly compared to the CK treatment, and that the effect size increased with biochar application rate. The B9.0 treatment showed the same effect on MBC as the SR treatment. Treatments effects on soil MBN were less strong than for MBC. The microbial biomass C∶N ratio was significantly increased by biochar. Biochar might decrease the fraction of biomass N mineralized (K N), which would make the soil MBN for biochar treatments underestimated, and microbial biomass C∶N ratios overestimated. Seasonal fluctuation in MBC was less for biochar amended soils than for CK and SR treatments, suggesting that biochar induced a less extreme environment for microorganisms throughout the season. There was a significant positive correlation between MBC and soil water content (SWC), but there was no significant correlation between MBC and soil temperature. Biochar amendments may therefore reduce temporal variability in environmental conditions for microbial growth in this system thereby reducing temporal fluctuations in C and N dynamics. PMID:25025330

  20. Effects of biochar on soil microbial biomass after four years of consecutive application in the north China Plain.

    Directory of Open Access Journals (Sweden)

    Qing-zhong Zhang

    Full Text Available The long term effect of biochar application on soil microbial biomass is not well understood. We measured soil microbial biomass carbon (MBC and nitrogen (MBN in a field experiment during a winter wheat growing season after four consecutive years of no (CK, 4.5 (B4.5 and 9.0 t biochar ha(-1 yr(-1 (B9.0 applied. For comparison, a treatment with wheat straw residue incorporation (SR was also included. Results showed that biochar application increased soil MBC significantly compared to the CK treatment, and that the effect size increased with biochar application rate. The B9.0 treatment showed the same effect on MBC as the SR treatment. Treatments effects on soil MBN were less strong than for MBC. The microbial biomass C∶N ratio was significantly increased by biochar. Biochar might decrease the fraction of biomass N mineralized (KN, which would make the soil MBN for biochar treatments underestimated, and microbial biomass C∶N ratios overestimated. Seasonal fluctuation in MBC was less for biochar amended soils than for CK and SR treatments, suggesting that biochar induced a less extreme environment for microorganisms throughout the season. There was a significant positive correlation between MBC and soil water content (SWC, but there was no significant correlation between MBC and soil temperature. Biochar amendments may therefore reduce temporal variability in environmental conditions for microbial growth in this system thereby reducing temporal fluctuations in C and N dynamics.

  1. Gut Microbial Glycerol Metabolism as an Endogenous Acrolein Source

    OpenAIRE

    Zhang, Jianbo; Sturla, Shana; Lacroix, Christophe; Schwab, Clarissa

    2018-01-01

    ABSTRACT Acrolein is a highly reactive electrophile causing toxic effects, such as DNA and protein adduction, oxidative stress, endoplasmic reticulum stress, immune dysfunction, and membrane damage. This Opinion/Hypothesis provides an overview of endogenous and exogenous acrolein sources, acrolein’s mode of action, and its metabolic fate. Recent reports underpin the finding that gut microbial glycerol metabolism leading to the formation of reuterin is an additional source of endogenous acrole...

  2. Impact of phenazine-1-carboxylic acid upon iron speciation and microbial biomass in the rhizosphere of wheat

    Science.gov (United States)

    LeTourneau, M.; Marshall, M.; Grant, M.; Freeze, P.; Cliff, J. B.; Lai, B.; Strawn, D. G.; Thomashow, L. S.; Weller, D. M.; Harsh, J. B.

    2015-12-01

    Phenazine-1-carboxylic acid (PCA) is a redox-active antibiotic produced by diverse bacterial taxa, and has been shown to facilitate interactions between biofilms and iron (hydr)oxides in culture systems (Wang et al. 2011, J Bacteriol 192: 365). Because rhizobacterial biofilms are a major sink for plant-derived carbon and source for soil organic matter (SOM), and Fe (hydr)oxides have reactive surfaces that influence the stability of microbial biomass and SOM, PCA-producing rhizobacteria could influence soil carbon fluxes. Large populations of Pseudomonas fluorescens strains producing PCA in concentrations up to 1 μg/g root have been observed in the rhizosphere of non-irrigated wheat fields covering 1.56 million hectares of central Washington state. This is one of the highest concentrations ever reported for a natural antibiotic in a terrestrial ecosystem (Mavrodi et al. 2012, Appl Environ Microb 78: 804). Microscopic comparisons of PCA-producing (PCA+) and non-PCA-producing (PCA-) rhizobacterial colony morphologies, and comparisons of Fe extractions from rhizosphere soil inoculated with PCA+ and PCA- strains suggest that PCA promotes biofilm development as well as dramatic Fe transformations throughout the rhizosphere (unpublished data). In order to illustrate PCA-mediated interactions between biofilms and Fe (hydr)oxides in the rhizosphere, identify the specific Fe phases favored by PCA, and establish the ramifications for stability and distribution of microbial biomass and SOM, we have collected electron micrographs, X-ray fluorescence images, X-ray absorption near-edge spectra, and secondary-ion mass spectrometry images of wheat root sections inoculated with 15N-labelled PCA+ or PCA- rhizobacteria. These images and spectra allow us to assess the accumulation, turnover, and distribution of microbial biomass, the associations between Fe and other nutrients such as phosphorus, and the redox status and speciation of iron in the presence and absence of PCA. This

  3. Bioaugmentation for Electricity Generation from Corn Stover Biomass Using Microbial Fuel Cells

    KAUST Repository

    Wang, Xin

    2009-08-01

    Corn stover is usually treated by an energy-intensive or expensive process to extract sugars for bioenergy production. However, it is possible to directly generate electricity from corn stover in microbial fuel cells (MFCs) through the addition of microbial consortia specifically acclimated for biomass breakdown. A mixed culture that was developed to have a high saccharification rate with corn stover was added to singlechamber, air-cathode MFCs acclimated for power production using glucose. The MFC produced a maximum power of 331 mW/ m 2 with the bioaugmented mixed culture and corn stover, compared to 510 mW/m2 using glucose. Denaturing gradient gel electrophoresis (DGGE) showed the communities continued to evolve on both the anode and corn stover biomass over 60 days, with several bacteria identified including Rhodopseudomonas palustris. The use of residual solids from the steam exploded corn stover produced 8% more power (406 mW/m2) than the raw corn stover. These results show that it is possible to directly generate electricity from waste corn stover in MFCs through bioaugmentation using naturally occurring bacteria. © 2009 American Chemical Society.

  4. Responses of microbial biomass carbon and nitrogen to experimental warming: a meta-analysis

    Science.gov (United States)

    Xu, W.; Yuan, W.

    2017-12-01

    Soil microbes play important roles in regulating terrestrial carbon and nitrogen cycling and strongly influence feedbacks of ecosystem to global warming. However, the inconsistent responses of microbial biomass carbon (MBC) and nitrogen (MBN) to experimental warming have been observed, and the response on ratio between MBC and MBN (MBC:MBN) has not been identified. This meta-analysis synthesized the warming experiments at 58 sites globally to investigate the responses of MBC:MBN to climate warming. Our results showed that warming significantly increased MBC by 3.61 ± 0.80% and MBN by 5.85 ± 0.90% and thus decreased the MBC:MBN by 3.34 ± 0.66%. MBC showed positive responses to warming but MBN exhibited negative responses to warming at low warming magnitude (2°C) the results were inverted. The different effects of warming magnitude on microbial biomass resulted from the warming-induced decline in soil moisture and substrate supply. Moreover, MBC and MBN had strong positive responses to warming at the mid-term (3-4 years) or short-term (1-2 years) duration, but the responses tended to decrease at long-term (≥ 5 years) warming duration. This study fills the knowledge gap on the responses of MBC:MBN to warming and may benefit the development of coupled carbon and nitrogen models.

  5. Earthworms (Amynthas spp. increase common bean growth, microbial biomass, and soil respiration

    Directory of Open Access Journals (Sweden)

    Julierme Zimmer Barbosa

    2017-10-01

    Full Text Available Few studies have evaluated the effect of earthworms on plants and biological soil attributes, especially among legumes. The objective of this study was to evaluate the influence of earthworms (Amynthas spp. on growth in the common bean (Phaseolus vulgaris L. and on soil biological attributes. The experiment was conducted in a greenhouse using a completely randomized design with five treatments and eight repetitions. The treatments consisted of inoculation with five different quantities of earthworms of the genus Amynthas (0, 2, 4, 6, and 8 worms per pot. Each experimental unit consisted of a plastic pot containing 4 kg of soil and two common bean plants. The experiment was harvested 38 days after seedling emergence. Dry matter and plant height, soil respiration, microbial respiration, microbial biomass, and metabolic quotient were determined. Earthworm recovery in our study was high in number and mass, with all values above 91.6% and 89.1%, respectively. In addition, earthworm fresh biomass decreased only in the treatment that included eight earthworms per pot. The presence of earthworms increased the plant growth and improved soil biological properties, suggesting that agricultural practices that favor the presence of these organisms can be used to increase the production of common bean, and the increased soil CO2 emission caused by the earthworms can be partially offset by the addition of common bean crop residues to the soil.

  6. Microbial biomass and soil fauna during the decomposition of cover crops in no-tillage system

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    Luciano Colpo Gatiboni

    2011-08-01

    Full Text Available The decomposition of plant residues is a biological process mediated by soil fauna, but few studies have been done evaluating its dynamics in time during the process of disappearance of straw. This study was carried out in Chapecó, in southern Brazil, with the objective of monitoring modifications in soil fauna populations and the C content in the soil microbial biomass (C SMB during the decomposition of winter cover crop residues in a no-till system. The following treatments were tested: 1 Black oat straw (Avena strigosa Schreb.; 2 Rye straw (Secale cereale L.; 3 Common vetch straw (Vicia sativa L.. The cover crops were grown until full flowering and then cut mechanically with a rolling stalk chopper. The soil fauna and C content in soil microbial biomass (C SMB were assessed during the period of straw decomposition, from October 2006 to February 2007. To evaluate C SMB by the irradiation-extraction method, soil samples from the 0-10 cm layer were used, collected on eight dates, from before until 100 days after residue chopping. The soil fauna was collected with pitfall traps on seven dates up to 85 days after residue chopping. The phytomass decomposition of common vetch was faster than of black oat and rye residues. The C SMB decreased during the process of straw decomposition, fastest in the treatment with common vetch. In the common vetch treatment, the diversity of the soil fauna was reduced at the end of the decomposition process.

  7. Biomass - alternative renewable energy source to the fossil fuels

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    Koruba Dorota

    2017-01-01

    Full Text Available The article presents the fossil fuels combustion effects in terms of the dangers of increasing CO2 concentration in the atmosphere. Based on the bibliography review the negative impact of increased carbon dioxide concentration on the human population is shown in the area of the external environment, particularly in terms of the air pollution and especially the impact on human health. The paper presents biomass as the renewable energy alternative source to fossil fuels which combustion gives a neutral CO2 emissions and therefore should be the main carrier of primary energy in Poland. The paper presents the combustion heat results and humidity of selected dry wood pellets (pellets straw, energy-crop willow pellets, sawdust pellets, dried sewage sludge from two sewage treatment plants of the Holly Cross province pointing their energy potential. In connection with the results analysis of these studies the standard requirements were discussed (EN 14918:2010 “Solid bio-fuels-determination of calorific value” regarding the basic parameters determining the biomass energy value (combustion heat, humidity.

  8. Biomass of Microalgae as a Source of Renewable Energy

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    Głowacka Natalia

    2017-05-01

    Full Text Available Algae represent a potential source of energy via anaerobic digestion. The aim of the study was to obtain the possible potential of green microalgae, which could replace the commonly used corn silage for the production of biogas in the future. The intensive construction of new biogas plants stations across Europe and the lack of arable land suitable for the cultivation of biomass for energy purposes are the fundamental reasons behind looking for the alternative raw materials for energy production as a substitute for commonly used input materials. When comparing green microalgae with conventional crops the high productivity potential (high oil content as well as the possibility of their production during the whole year can be noticed. It is necessary to find the effective way to produce biomass from green microalgae, proper for energy conversion, while ensuring the economic and environmental aspects. The interim research results mentioned in this article indicate that microalgae present appropriate alternative material for the process of anaerobic digestion.

  9. Soil microbial biomass under different management and tillage systems of permanent intercropped cover species in an orange orchard

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    Elcio Liborio Balota

    2011-12-01

    Full Text Available To mitigate soil erosion and enhance soil fertility in orange plantations, the permanent protection of the inter-rows by cover species has been suggested. The objective of this study was to evaluate alterations in the microbial biomass, due to different soil tillage systems and intercropped cover species between rows of orange trees. The soil of the experimental area previously used as pasture (Brachiaria humidicola was an Ultisol (Typic Paleudult originating from Caiuá sandstone in the northwestern part of the State of Paraná, Brazil. Two soil tillage systems were evaluated: conventional tillage (CT in the entire area and strip tillage (ST (strip width 2 m, in combination with different ground cover management systems. The citrus cultivar 'Pera' orange (Citrus sinensis grafted onto 'Rangpur' lime rootstock was used. Soil samples were collected after five years of treatment from a depth of 0-15 cm, under the tree canopy and in the inter-row, in the following treatments: (1 CT and an annual cover crop with the leguminous species Calopogonium mucunoides; (2 CT and a perennial cover crop with the leguminous peanut Arachis pintoi; (3 CT and an evergreen cover crop with Bahiagrass Paspalum notatum; (4 CT and a cover crop with spontaneous Brachiaria humidicola grass vegetation; and (5 ST and maintenance of the remaining grass (pasture of Brachiaria humidicola. Soil tillage and the different cover species influenced the microbial biomass, both under the tree canopy and in the inter-row. The cultivation of brachiaria increased C and N in the microbial biomass, while bahiagrass increased P in the microbial biomass. The soil microbial biomass was enriched in N and P by the presence of ground cover species and according to the soil P content. The grass species increased C, N and P in the soil microbial biomass from the inter-row more than leguminous species.

  10. Field and lab conditions alter microbial enzyme and biomass dynamics driving decomposition of the same leaf litter

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    Zachary L Rinkes

    2013-09-01

    Full Text Available Fluctuations in climate and edaphic factors influence field decomposition rates and preclude a complete understanding of how microbial communities respond to plant litter quality. In contrast, laboratory microcosms isolate the intrinsic effects of litter chemistry and microbial community from extrinsic effects of environmental variation. Used together, these paired approaches provide mechanistic insights to decomposition processes. In order to elucidate the microbial mechanisms underlying how environmental conditions alter the trajectory of decay, we characterized microbial biomass, respiration, enzyme activities, and nutrient dynamics during early (< 10% mass loss, mid- (10-40% mass loss, and late (> 40% mass loss decay in parallel field and laboratory litter bag incubations for deciduous tree litters with varying recalcitrance (dogwood < maple < maple-oak mixture < oak. In the field, mass loss was minimal (< 10% over the first 50 days (January-February, even for labile litter types, despite above-freezing soil temperatures and adequate moisture during these winter months. In contrast, microcosms displayed high C mineralization rates in the first week. During mid-decay, the labile dogwood and maple litters in the field had higher mass loss per unit enzyme activity than the lab, possibly due to leaching of soluble compounds. Microbial biomass to litter mass (B:C ratios peaked in the field during late decay, but B:C ratios declined between mid- and late decay in the lab. Thus, microbial biomass did not have a consistent relationship with litter quality between studies. Higher oxidative enzyme activities in oak litters in the field, and higher nitrogen (N accumulation in the lab microcosms occurred in late decay. We speculate that elevated N suppressed fungal activity and/or biomass in microcosms. Our results suggest that differences in microbial biomass and enzyme dynamics alter the decay trajectory of the same leaf litter under field and lab

  11. Field and lab conditions alter microbial enzyme and biomass dynamics driving decomposition of the same leaf litter.

    Science.gov (United States)

    Rinkes, Zachary L; Sinsabaugh, Robert L; Moorhead, Daryl L; Grandy, A Stuart; Weintraub, Michael N

    2013-01-01

    Fluctuations in climate and edaphic factors influence field decomposition rates and preclude a complete understanding of how microbial communities respond to plant litter quality. In contrast, laboratory microcosms isolate the intrinsic effects of litter chemistry and microbial community from extrinsic effects of environmental variation. Used together, these paired approaches provide mechanistic insights to decomposition processes. In order to elucidate the microbial mechanisms underlying how environmental conditions alter the trajectory of decay, we characterized microbial biomass, respiration, enzyme activities, and nutrient dynamics during early (40% mass loss) decay in parallel field and laboratory litter bag incubations for deciduous tree litters with varying recalcitrance (dogwood litter types, despite above-freezing soil temperatures and adequate moisture during these winter months. In contrast, microcosms displayed high C mineralization rates in the first week. During mid-decay, the labile dogwood and maple litters in the field had higher mass loss per unit enzyme activity than the lab, possibly due to leaching of soluble compounds. Microbial biomass to litter mass (B:C) ratios peaked in the field during late decay, but B:C ratios declined between mid- and late decay in the lab. Thus, microbial biomass did not have a consistent relationship with litter quality between studies. Higher oxidative enzyme activities in oak litters in the field, and higher nitrogen (N) accumulation in the lab microcosms occurred in late decay. We speculate that elevated N suppressed fungal activity and/or biomass in microcosms. Our results suggest that differences in microbial biomass and enzyme dynamics alter the decay trajectory of the same leaf litter under field and lab conditions.

  12. Effects of fire on soil nitrogen dynamics and microbial biomass in savannas of Central Brazil

    Directory of Open Access Journals (Sweden)

    Nardoto Gabriela Bielefeld

    2003-01-01

    Full Text Available The objective of this work was to study the effects of fire on net N mineralization and soil microbial biomass in burned and unburned cerrado stricto sensu sites. The study was carried out from April 1998 to April 2000. The pH values were significantly higher in the burned site while soil moisture content was significantly higher in the unburned site (P<0.05. The soil C/N ratio was 22/1 and the available NO3-N ranged between 1.5 and 2.8 mg kg-¹ dry weight. However, the NH4-N concentration ranged between 3 and 34 mg kg-1 dry weight in the burned site and between 3 and 22 mg kg-1 dry weight in the unburned site. The NH4-N increased after fire, but no significant changes were observed for NO3-N (P<0.05. The NO3-N accumulation occurred in short periods during the rainy season. The rates of net N mineralization increased during the rainy season while reductions in soil microbial biomass were observed at both sites. This suggested that the peak in microbial activities occurred with the first rain events, with an initial net immobilization followed by net mineralization. Both sites presented the same pattern for mineralization/immobilization, however, the amount of inorganic-N cycled annually in unburned site was 14.7 kg ha-1 per year while the burned site presented only 3.8 kg ha-¹ of inorganic-N, one year after the burning.

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

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    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.

  14. 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

  15. Photosynthetic microbial desalination cells (PMDCs) for clean energy, water and biomass production.

    Science.gov (United States)

    Kokabian, Bahareh; Gude, Veera Gnaneswar

    2013-12-01

    Current microbial desalination cell (MDC) performances are evaluated with chemical catalysts such as ferricyanide, platinum catalyzed air-cathodes or aerated cathodes. All of these methods improve power generation potential in MDCs, however, they are not preferable for large scale applications due to cost, energy and environmental toxicity issues. In this study, performance of microbial desalination cells with an air cathode and an algae biocathode (Photosynthetic MDC - PMDC) were evaluated, both under passive conditions (no mechanical aeration or mixing). The results indicate that passive algae biocathodes perform better than air cathodes and enhance COD removal and utilize treated wastewater as the growth medium to obtain valuable biomass for high value bioproducts. Maximum power densities of 84 mW m(-3) (anode volume) or 151 mW m(-3) (biocathode volume) and a desalination rate of 40% were measured with 0.9 : 1 : 0.5 volumetric ratios of anode, desalination and algae biocathode chambers respectively. This first proof-of-concept study proves that the passive mechanisms can be beneficial in enhancing the sustainability of microbial desalination cells.

  16. A stepwise-cluster microbial biomass inference model in food waste composting

    International Nuclear Information System (INIS)

    Sun Wei; Huang, Guo H.; Zeng Guangming; Qin Xiaosheng; Sun Xueling

    2009-01-01

    A stepwise-cluster microbial biomass inference (SMI) model was developed through introducing stepwise-cluster analysis (SCA) into composting process modeling to tackle the nonlinear relationships among state variables and microbial activities. The essence of SCA is to form a classification tree based on a series of cutting or mergence processes according to given statistical criteria. Eight runs of designed experiments in bench-scale reactors in a laboratory were constructed to demonstrate the feasibility of the proposed method. The results indicated that SMI could help establish a statistical relationship between state variables and composting microbial characteristics, where discrete and nonlinear complexities exist. Significance levels of cutting/merging were provided such that the accuracies of the developed forecasting trees were controllable. Through an attempted definition of input effects on the output in SMI, the effects of the state variables on thermophilic bacteria were ranged in a descending order as: Time (day) > moisture content (%) > ash content (%, dry) > Lower Temperature (deg. C) > pH > NH 4 + -N (mg/Kg, dry) > Total N (%, dry) > Total C (%, dry); the effects on mesophilic bacteria were ordered as: Time > Upper Temperature (deg. C) > Total N > moisture content > NH 4 + -N > Total C > pH. This study made the first attempt in applying SCA to mapping the nonlinear and discrete relationships in composting processes.

  17. Nitrogen fractions in the microbial biomass in soils of southern Brazil

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    F. A.O. Camargo

    1999-03-01

    Full Text Available The reaction of nitrogen compounds with ninhydrin can be used as an indicator of cytoplasmic materials released from microbial cells killed by fumigation. Total-N, ninhydrin-reactive-N (NR-N, ammonium-N (A-N, and α-amino-N in the microbial biomass of soils from the State of Rio Grande do Sul, Brazil, were determined, in 1996, in 0.5 mol L-1 K2SO4 extracts of fumigated and non-fumigated soils. Total-N varied from 20.3 to 104.4 mg kg-1 and the ninhydrin-reactive-N corresponded, in average, to 27% of this. The ninhydrin-reactive-N was made up of 67% ammonium-N and 33% aminoacids with the amino group at the α-carbon position. It was concluded that colorimetric analysis of NR-N and A-N may be used as a direct measure of microbial N in soil. This simple and rapid procedure is adequate for routine analyses.

  18. Biomass: An Alternative Source of Energy for Eighth or Ninth Grade Science.

    Science.gov (United States)

    Heyward, Lillie; Murff, Marye

    This teaching unit develops the possibility of using biomass as an alternative source of energy. The concept of biomass is explained and the processes associated with its conversion to energy are stated. Suggestions for development of biomass technology in different geographic areas are indicated. Lessons for 6 days are presented for use with…

  19. Microbial respiration, but not biomass, responded linearly to increasing light fraction organic matter input: Consequences for carbon sequestration.

    Science.gov (United States)

    Rui, Yichao; Murphy, Daniel V; Wang, Xiaoli; Hoyle, Frances C

    2016-10-18

    Rebuilding 'lost' soil carbon (C) is a priority in mitigating climate change and underpinning key soil functions that support ecosystem services. Microorganisms determine if fresh C input is converted into stable soil organic matter (SOM) or lost as CO 2 . Here we quantified if microbial biomass and respiration responded positively to addition of light fraction organic matter (LFOM, representing recent inputs of plant residue) in an infertile semi-arid agricultural soil. Field trial soil with different historical plant residue inputs [soil C content: control (tilled) = 9.6 t C ha -1 versus tilled + plant residue treatment (tilled + OM) = 18.0 t C ha -1 ] were incubated in the laboratory with a gradient of LFOM equivalent to 0 to 3.8 t C ha -1 (0 to 500% LFOM). Microbial biomass C significantly declined under increased rates of LFOM addition while microbial respiration increased linearly, leading to a decrease in the microbial C use efficiency. We hypothesise this was due to insufficient nutrients to form new microbial biomass as LFOM input increased the ratio of C to nitrogen, phosphorus and sulphur of soil. Increased CO 2 efflux but constrained microbial growth in response to LFOM input demonstrated the difficulty for C storage in this environment.

  20. Microbial biomass and viral infections of heterotrophic prokaryotes in the sub-surface layer of the central Arctic Ocean

    Science.gov (United States)

    Steward, Grieg F.; Fandino, Laura B.; Hollibaugh, James T.; Whitledge, Terry E.; Azam, Farooq

    2007-10-01

    Seawater samples were collected for microbial analyses between 55 and 235 m depth across the Arctic Ocean during the SCICEX 97 expedition (03 September-02 October 1997) using a nuclear submarine as a research platform. Abundances of prokaryotes (range 0.043-0.47×10 9 dm -3) and viruses (range 0.68-11×10 9 dm -3) were correlated ( r=0.66, n=150) with an average virus:prokaryote ratio of 26 (range 5-70). Biomass of prokaryotes integrated from 55 to 235 m ranged from 0.27 to 0.85 g C m -2 exceeding that of phytoplankton (0.005-0.2 g C m -2) or viruses (0.02-0.05 g C m -2) over the same depth range by an order of magnitude on average. Using transmission electron microscopy (TEM), we estimated that 0.5% of the prokaryote community on average (range 0-1.4%) was visibly infected with viruses, which suggests that very little of prokaryotic secondary production was lost due to viral lysis. Intracellular viruses ranged from 5 to >200/cell, with an average apparent burst size of 45±38 (mean±s.d.; n=45). TEM also revealed the presence of putative metal-precipitating bacteria in 8 of 13 samples, which averaged 0.3% of the total prokaryote community (range 0-1%). If these prokaryotes are accessible to protistan grazers, the Fe and Mn associated with their capsules might be an important source of trace metals to the planktonic food web. After combining our abundance and mortality data with data from the literature, we conclude that the biomass of prokaryoplankton exceeds that of phytoplankton when averaged over the upper 250 m of the central Arctic Ocean and that the fate of this biomass is poorly understood.

  1. Microbial biodiesel production from oil palm biomass hydrolysate using marine Rhodococcus sp. YHY01.

    Science.gov (United States)

    Bhatia, Shashi Kant; Kim, Junyoung; Song, Hun-Seok; Kim, Hyun Joong; Jeon, Jong-Min; Sathiyanarayanan, Ganesan; Yoon, Jeong-Jun; Park, Kyungmoon; Kim, Yun-Gon; Yang, Yung-Hun

    2017-06-01

    The effect of various biomass derived inhibitors (i.e. furfural, hydroxymethylfurfural (HMF), vanillin, 4-hydroxy benzaldehyde (4-HB) and acetate) was investigated for fatty acid accumulation in Rhodococcus sp. YHY 01. Rhodococcus sp. YHY01 was able to utilize acetate, vanillin, and 4-HB for biomass production and fatty acid accumulation. The IC 50 value for furfural (3.1mM), HMF (3.2mM), vanillin (2.0mM), 4-HB (2.7mM) and acetate (3.7mM) was calculated. HMF and vanillin affect fatty acid composition and increase saturated fatty acid content. Rhodococcus sp. YHY 01 cultured with empty fruit bunch hydrolysate (EFBH) as the main carbon source resulted in enhanced biomass (20%) and fatty acid productivity (37%), in compression to glucose as a carbon source. Overall, this study showed the beneficial effects of inhibitory molecules on growth and fatty acid production, and support the idea of biomass hydrolysate utilization for biodiesel production by avoiding complex efforts to remove inhibitory compounds. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. D:L-AMINO Acids and the Turnover of Microbial Biomass

    Science.gov (United States)

    Lomstein, B. A.; Braun, S.; Mhatre, S. S.; Jørgensen, B. B.

    2015-12-01

    Decades of ocean drilling have demonstrated wide spread microbial life in deep sub-seafloor sediment, and surprisingly high microbial cell numbers. Despite the ubiquity of life in the deep biosphere, the large community sizes and the low energy fluxes in the vast buried ecosystem are still poorly understood. It is not know whether organisms of the deep biosphere are specifically adapted to extremely low energy fluxes or whether most of the observed cells are in a maintenance state. Recently we developed and applied a new culture independent approach - the D:L-amino acid model - to quantify the turnover times of living microbial biomass, microbial necromass and mean metabolic rates. This approach is based on the built-in molecular clock in amino acids that very slowly undergo chemical racemization until they reach an even mixture of L- and D- forms, unless microorganisms spend energy to keep them in the L-form that dominates in living organisms. The approach combines sensitive analyses of amino acids, the unique bacterial endospore marker (dipicolinic acid) with racemization dynamics of stereo-isomeric amino acids. Based on a heating experiment, we recently reported kinetic parameters for racemization of aspartic acid, glutamic acid, serine and alanine in bulk sediment from Aarhus Bay, Denmark. The obtained racemization rate constants were faster than the racemization rate constants of free amino acids, which we have previously applied in Holocene sediment from Aarhus Bay and in up to 10 mio yr old sediment from ODP Leg 201. Another important input parameter for the D:L-amino acid model is the cellular carbon content. It has recently been suggested that the cellular carbon content most likely is lower than previously thought. In recognition of these new findings, previously published data based on the D:L-amino acid model were recalculated and will be presented together with new data from an Arctic Holocene setting with constant sub-zero temperatures.

  3. Soil respiration, microbial biomass and exoenzyme activity in switchgrass stands under nitrogen fertilization management and climate warming.

    Science.gov (United States)

    Jian, S.; Li, J.; de Koff, J.; Celada, S.; Mayes, M. A.; Wang, G.; Guo, C.

    2016-12-01

    Switchgrass (Panicum virgatum L.), as a model bioenergy crop, received nitrogen fertilizers for increasing its biomass yields. Studies rarely investigate the interactive effects of nitrogen fertilization and climate warming on soil microbial activity and carbon cycling in switchgrass cropping systems. Enhanced nitrogen availability under fertilization can alter rates of soil organic matter decomposition and soil carbon emissions to the atmosphere and thus have an effect on climate change. Here, we assess soil CO2 emission, microbial biomass and exoenzyme activities in two switchgrass stands with no fertilizer and 60 lbs N / acre. Soils were incubated at 15 ºC and 20 ºC for 180-day. Dry switchgrass plant materials were added to incubation jars and the 13C stable isotopic probing technique was used to monitor soil CO2 respiration derived from relatively labile litter and indigenous soil. Measurements of respiration, δ13C of respiration, microbial biomass carbon and exoenzyme activity were performed on days 1, 5, 10, 15, 30, 60, 90, 120, 150 and 180. Soil respiration rate was greater in the samples incubated at 20 ºC as compared to those incubated at 15 ºC. Exoenzyme activities were significantly altered by warming, litter addition and nitrogen fertilization. There was a significant interactive effect of nitrogen fertilization and warming on the proportion of CO2 respired from soils such that nitrogen fertilization enhanced warming-induced increase by 12.0% (Pmineralization. Fertilization increased soil microbial biomass carbon at both temperatures (9.0% at 15 ºC and 14.5% at 20 ºC). Our preliminary analysis suggested that warming effects on enhanced soil respiration can be further increased with elevated fertilizer input via greater microbial biomass and exoenzyme activity. In addition to greater biomass yield under N fertilization, this study informs potential soil carbon loss from stimulated soil respiration under nitrogen fertilization and warming in

  4. Medium activity long-lived nuclear waste; microbial paradise or hadean environment - Evaluation of biomass and impact on redox conditions

    International Nuclear Information System (INIS)

    Albrecht, A.; Libert, M.

    2010-01-01

    Document available in extended abstract form only. The evaluation of the impact of possible microbial activity in nuclear waste cells has been a subject for more than a quarter of a century. Some of the items of interest in relation to microbial impact on near field biogeochemistry indicated in Table 1 had already been known as pertinent. Recently, it became clear that a distinction needed to be made between high-level, vitrified waste and organic matter containing intermediate-level waste, of which the bituminized waste is used as an example here. For high-level waste the canister walls play an important safety role and the most probable limiting aspects, next to space and water, are the low concentrations in organic matter as a carbon source and phosphorous and nitrogen as essential elements. In this particular case, microbially induced corrosion is of primary concern. In the case of the French intermediate bituminized waste, primary interest is on the impact of microbial activity on redox reactions, with the high pH environment, as a consequence of the concrete engineered barrier, as the most probable limiting condition. The canister wall has no explicit long-term safety role and all components for microbial activity will become readily available. The presence of nitrates, sulphates and Fe(III) as electron acceptors and organic matter, hydrogen gas and zero-valent metals (i.e. Fe) as electron donors allows the system to supply energy for bacterial activity and to move through the entire redox sequence from O 2 (present only shortly after waste-cell closure) to nitrate, Fe(III), sulphate and organic matter reduction. Prevailing uncertainties do not allow specification of timing for the redox-changes. These uncertainties are essentially related to the lack of knowledge regarding microbial catalysis. As no natural or anthropogenic analogues are available, parameters need to be obtained from experiments. Two approaches will be presented that allow estimation of the

  5. Evaluation and Selection of Potential Biomass Sources of North-East India towards Sustainable Bioethanol Production

    International Nuclear Information System (INIS)

    Nongthombam, Grihalakshmi D.; Labala, Rajendra K.; Das, Sudripta; Handique, Pratap J.; Talukdar, Narayan C.

    2017-01-01

    Vegetation biomass production in North-East India within Indo-Burma biodiversity hotspot is luxuriant and available from April to October to consider their potential for bioethanol production. Potential of six lignocellulosic biomass (LCB) sources; namely, sugarcane bagasse (BG), cassava aerial parts (CS), ficus fruits (Ficus cunia) (FF), “phumdi” (floating biomass), rice straw (RS), and sawdust were investigated for bioethanol production using standard techniques. Morphological and chemical changes were evaluated by Scanning electron microscopy and Fourier transform infrared spectroscopy and quantity of sugars and inhibitors in LCB were determined by High performance liquid chromatography. Hydrothermally treated BG, CS, and FF released 954.54, 1,354.33, and 1,347.94 mg/L glucose and 779.31, 612.27, and 1,570.11 mg/L of xylose, respectively. Inhibitors produced due to effect of hydrothermal pretreatment ranged from 42.8 to 145.78 mg/L acetic acid, below detection level (BDL) to 17.7 µg/L 5-hydroxymethylfurfural, and BDL to 56.78 µg/L furfural. The saccharification efficiency of hydrothermally treated LCB (1.35–28.64%) was significantly higher compared with their native counterparts (0.81–17.97%). Consolidated bioprocessing of the LCB using MTCC 1755 (Fusarium oxysporum) resulted in maximum ethanol concentration of 0.85 g/L and corresponded to 42 mg ethanol per gram of hydrothermally treated BG in 120 h followed by 0.83 g/L corresponding to 41.5 mg/g of untreated CS in 144 h. These ethanol concentrations corresponded to 23.43 and 21.54% of theoretical ethanol yield, respectively. LCB of CS and FF emerged as a suitable material to be subjected to test for enhanced ethanol production in future experiments through efficient fermentative microbial strains, appropriate enzyme loadings, and standardization of other fermentation parameters.

  6. Evaluation and Selection of Potential Biomass Sources of North-East India towards Sustainable Bioethanol Production

    Energy Technology Data Exchange (ETDEWEB)

    Nongthombam, Grihalakshmi D., E-mail: griha789@gmail.com; Labala, Rajendra K.; Das, Sudripta [Institute of Bioresources and Sustainable Development (IBSD), Imphal (India); Handique, Pratap J. [Department of Biotechnology, Gauhati University, Guwahati (India); Talukdar, Narayan C., E-mail: griha789@gmail.com [Division of Life Sciences, Institute of Advanced Study in Science and Technology, Guwahati (India)

    2017-07-11

    Vegetation biomass production in North-East India within Indo-Burma biodiversity hotspot is luxuriant and available from April to October to consider their potential for bioethanol production. Potential of six lignocellulosic biomass (LCB) sources; namely, sugarcane bagasse (BG), cassava aerial parts (CS), ficus fruits (Ficus cunia) (FF), “phumdi” (floating biomass), rice straw (RS), and sawdust were investigated for bioethanol production using standard techniques. Morphological and chemical changes were evaluated by Scanning electron microscopy and Fourier transform infrared spectroscopy and quantity of sugars and inhibitors in LCB were determined by High performance liquid chromatography. Hydrothermally treated BG, CS, and FF released 954.54, 1,354.33, and 1,347.94 mg/L glucose and 779.31, 612.27, and 1,570.11 mg/L of xylose, respectively. Inhibitors produced due to effect of hydrothermal pretreatment ranged from 42.8 to 145.78 mg/L acetic acid, below detection level (BDL) to 17.7 µg/L 5-hydroxymethylfurfural, and BDL to 56.78 µg/L furfural. The saccharification efficiency of hydrothermally treated LCB (1.35–28.64%) was significantly higher compared with their native counterparts (0.81–17.97%). Consolidated bioprocessing of the LCB using MTCC 1755 (Fusarium oxysporum) resulted in maximum ethanol concentration of 0.85 g/L and corresponded to 42 mg ethanol per gram of hydrothermally treated BG in 120 h followed by 0.83 g/L corresponding to 41.5 mg/g of untreated CS in 144 h. These ethanol concentrations corresponded to 23.43 and 21.54% of theoretical ethanol yield, respectively. LCB of CS and FF emerged as a suitable material to be subjected to test for enhanced ethanol production in future experiments through efficient fermentative microbial strains, appropriate enzyme loadings, and standardization of other fermentation parameters.

  7. Microbial biomass and carbon mineralization in agricultural soils as affected by pesticide addition.

    Science.gov (United States)

    Kumar, Anjani; Nayak, A K; Shukla, Arvind K; Panda, B B; Raja, R; Shahid, Mohammad; Tripathi, Rahul; Mohanty, Sangita; Rath, P C

    2012-04-01

    A laboratory study was conducted with four pesticides, viz. a fungicide (carbendazim), two insecticides (chlorpyrifos and cartap hydrochloride) and an herbicide (pretilachlor) applied to a sandy clay loam soil at a field rate to determine their effect on microbial biomass carbon (MBC) and carbon mineralization (C(min)). The MBC content of soil increased with time up to 30 days in cartap hydrochloride as well as chlorpyrifos treated soil. Thereafter, it decreased and reached close to the initial level by 90th day. However, in carbendazim treated soil, the MBC showed a decreasing trend up to 45 days and subsequently increased up to 90 days. In pretilachlor treated soil, MBC increased through the first 15 days, and thereafter decreased to the initial level. Application of carbendazim, chlorpyrifos and cartap hydrochloride decreased C(min) for the first 30 days and then increased afterwards, while pretilachlor treated soil showed an increasing trend.

  8. Enzyme activities and microbial biomass in topsoil layer during spontaneous succession in spoil heaps after brown coal mining

    Czech Academy of Sciences Publication Activity Database

    Baldrian, Petr; Trögl, Josef; Frouz, Jan; Šnajdr, Jaroslav; Valášková, Vendula; Merhautová, Věra; Cajthaml, Tomáš; Herinková, Jana

    2008-01-01

    Roč. 40, č. 9 (2008), s. 2107-2115 ISSN 0038-0717 R&D Projects: GA MŠk LC06066 Institutional research plan: CEZ:AV0Z50200510; CEZ:AV0Z60660521 Keywords : enzyme activity * lignocellulose * microbial biomass Subject RIV: EH - Ecology, Behaviour Impact factor: 2.926, year: 2008

  9. Soil-derived microbial consortia enriched with different plant biomass reveal distinct players acting in lignocellulose degradation

    NARCIS (Netherlands)

    de Lima Brossi, Maria Julia; Jiménez Avella, Diego; Cortes Tolalpa, Larisa; van Elsas, Jan

    Here, we investigated how different plant biomass, and-for one substrate-pH, drive the composition of degrader microbial consortia. We bred such consortia from forest soil, incubated along nine aerobic sequential - batch enrichments with wheat straw (WS1, pH 7.2; WS2, pH 9.0), switchgrass (SG, pH

  10. Effects of phosphorus addition on soil microbial biomass and community composition in three forest types in tropical China

    DEFF Research Database (Denmark)

    Liu, Lei; Gundersen, Per; Zhang, Tao

    2012-01-01

    Elevated nitrogen (N) deposition in humid tropical regions may aggravate phosphorus (P) deficiency in forest on old weathered soil found in these regions. From January 2007 to August 2009, we studied the responses of soil microbial biomass and community composition to P addition (in two monthly...

  11. Microbial biomass and bacterial functional diversity in forest soils: effects of organic matter removal, compaction, and vegetation control

    Science.gov (United States)

    Qingchao Li; H. Lee Allen; Arthur G. Wollum

    2004-01-01

    The effects of organic matter removal, soil compaction, and vegetation control on soil microbial biomass carbon, nitrogen, C-to-N ratio, and functional diversity were examined in a 6-year loblolly pine plantation on a Coastal Plain site in eastern North Carolina, USA. This experimental plantation was established as part of the US Forest Service's Long Term Soil...

  12. Sedimentary organic biomarkers suggest detrimental effects of PAHs on estuarine microbial biomass during the 20th century in San Francisco Bay, CA, USA

    Science.gov (United States)

    Nilsen, Elena B.; Rosenbauer, Robert J.; Fuller, Christopher C.; Jaffe, Bruce E.

    2014-01-01

    Hydrocarbon contaminants are ubiquitous in urban aquatic ecosystems, and the ability of some microbial strains to degrade certain polycyclic aromatic hydrocarbons (PAHs) is well established. However, detrimental effects of petroleum hydrocarbon contamination on nondegrader microbial populations and photosynthetic organisms have not often been considered. In the current study, fatty acid methyl ester (FAME) biomarkers in the sediment record were used to assess historical impacts of petroleum contamination on microbial and/or algal biomass in South San Francisco Bay, CA, USA. Profiles of saturated, branched, and monounsaturated fatty acids had similar concentrations and patterns downcore. Total PAHs in a sediment core were on average greater than 20× higher above ∼200 cm than below, which corresponds roughly to the year 1900. Isomer ratios were consistent with a predominant petroleum combustion source for PAHs. Several individual PAHs exceeded sediment quality screening values. Negative correlations between petroleum contaminants and microbial and algal biomarkers – along with high trans/cis ratios of unsaturated FA, and principle component analysis of the PAH and fatty acid records – suggest a negative impacts of petroleum contamination, appearing early in the 20th century, on microbial and/or algal ecology at the site.

  13. [Dynamics of microbial biomass carbon and nitrogen during foliar litter decomposition under artificial forest gap in Pinus massoniana plantation.

    Science.gov (United States)

    Zhang, Ming Jin; Chen, Liang Hua; Zhang, Jian; Yang, Wan Qin; Liu, Hua; Li, Xun; Zhang, Yan

    2016-03-01

    Nowadays large areas of plantations have caused serious ecological problems such as soil degradation and biodiversity decline. Artificial tending thinning and construction of mixed forest are frequently used ways when we manage plantations. To understand the effect of this operation mode on nutrient cycle of plantation ecosystem, we detected the dynamics of microbial bio-mass carbon and nitrogen during foliar litter decomposition of Pinus massoniana and Toona ciliate in seven types of gap in different sizes (G 1 : 100 m 2 , G 2 : 225 m 2 , G 3 : 400 m 2 , G 4 : 625 m 2 , G 5 : 900 m 2 , G 6 : 1225 m 2 , G 7 : 1600 m 2 ) of 42-year-old P. massoniana plantations in a hilly area of the upper Yang-tze River. The results showed that small and medium-sized forest gaps(G 1 -G 5 ) were more advantageous for the increment of microbial biomass carbon and nitrogen in the process of foliar litter decomposition. Along with the foliar litter decomposition during the experiment (360 d), microbial biomass carbon (MBC), microbial biomass nitrogen (MBN) in P. massoniana foliar litter and MBN in T. ciliata foliar litter first increased and then decreased, and respectively reached the maxima 9.87, 0.22 and 0.80 g·kg -1 on the 180 th d. But the peak (44.40 g·kg -1 ) of MBC in T. ciliata foliar litter appeared on the 90 th d. Microbial biomass carbon and nitrogen in T. ciliate was significantly higher than that of P. massoniana during foliar litter decomposition. Microbial biomass carbon and nitrogen in foliar litter was not only significantly associated with average daily temperature and the water content of foliar litter, but also closely related to the change of the quality of litter. Therefore, in the thinning, forest gap size could be controlled in the range of from 100 to 900 m 2 to facilitate the increase of microbial biomass carbon and nitrogen in the process of foliar litter decomposition, accelerate the decomposition of foliar litter and improve soil fertility of plantations.

  14. Potential of Livestock Generated Biomass: Untapped Energy Source in India

    Directory of Open Access Journals (Sweden)

    Gagandeep Kaur

    2017-06-01

    Full Text Available Modern economies run on the backbone of electricity as one of major factors behind industrial development. India is endowed with plenty of natural resources and the majority of electricity within the country is generated from thermal and hydro-electric plants. A few nuclear plants assist in meeting the national requirements for electricity but still many rural areas remain uncovered. As India is primarily a rural agrarian economy, providing electricity to the remote, undeveloped regions of the country remains a top priority of the government. A vital, untapped source is livestock generated biomass which to some extent has been utilized to generate electricity in small scale biogas based plants under the government's thrust on rural development. This study is a preliminary attempt to correlate developments in this arena in the Asian region, as well as the developed world, to explore the possibilities of harnessing this resource in a better manner. The current potential of 2600 million tons of livestock dung generated per year, capable of yielding 263,702 million m3 of biogas is exploited. Our estimates suggest that if this resource is utilized judiciously, it possesses the potential of generating 477 TWh (Terawatt hour of electrical energy per annum.

  15. Assimilable organic carbon (AOC in soil water extracts using Vibrio harveyi BB721 and its implication for microbial biomass.

    Directory of Open Access Journals (Sweden)

    Jincai Ma

    Full Text Available Assimilable organic carbon (AOC is commonly used to measure the growth potential of microorganisms in water, but has not yet been investigated for measuring microbial growth potential in soils. In this study, a simple, rapid, and non-growth based assay to determine AOC in soil was developed using a naturally occurring luminous strain Vibrio harveyi BB721 to determine the fraction of low molecular weight organic carbon in soil water extract. Calibration of the assay was achieved by measuring the luminescence intensity of starved V. harveyi BB721 cells in the late exponential phase with a concentration range from 0 to 800 µg l(-1 glucose (equivalent to 0-16.0 mg glucose C kg(-1 soil with the detection limit of 10 µg l(-1 equivalent to 0.20 mg glucose C kg(-1 soil. Results showed that bioluminescence was proportional to the concentration of glucose added to soil. The luminescence intensity of the cells was highly pH dependent and the optimal pH was about 7.0. The average AOC concentration in 32 soils tested was 2.9±2.2 mg glucose C kg(-1. Our data showed that AOC levels in soil water extracts were significantly correlated (P<0.05 with microbial biomass determined as microbial biomass carbon, indicating that the AOC concentrations determined by the method developed might be a good indicator of soil microbial biomass. Our findings provide a new approach that may be used to determine AOC in environmental samples using a non-growth bioluminescence based assay. Understanding the levels of AOC in soil water extract provides new insights into our ability to estimate the most available carbon pool to bacteria in soil that may be easily assimilated into cells for many metabolic processes and suggest possible the links between AOC, microbial regrowth potential, and microbial biomass in soils.

  16. Microbial Community Activity And Plant Biomass Are Insensitive To Passive Warming In A Semiarid Ecosystem

    Science.gov (United States)

    Espinosa, N. J.; Fehmi, J. S.; Rasmussen, C.; Gallery, R. E.

    2017-12-01

    Soil microorganisms drive biogeochemical and nutrient cycling through the production of extracellular enzymes that facilitate organic matter decomposition and the flux of large amounts of carbon dioxide to the atmosphere. Although dryland ecosystems occupy over 40% of land cover and are projected to expand due to climate change, much of our current understanding of these processes comes from mesic temperate ecosystems. Understanding the responses of these globally predominant dryland ecosystems is therefore important yet complicated by co-occurring environmental changes. For example, the widespread and pervasive transition from grass to woody dominated landscapes is changing the hydrology, fire regimes, and carbon storage potential of semiarid ecosystems. In this study, we used a novel passive method of warming to conduct a warming experiment with added plant debris as either woodchip or biochar, to simulate different long-term carbon additions that accompany woody plant encroachment in semiarid ecosystems. The response of heterotrophic respiration, plant biomass, and microbial activity was monitored bi-annually. We hypothesized that the temperature manipulations would have direct and indirect effects on microbial activity. Warmer soils directly reduce the activity of soil extracellular enzymes through denaturation and dehydration of soil pores and indirectly through reducing microbe-available substrates and plant inputs. Overall, reduction in extracellular enzyme activity may reduce decomposition of coarse woody debris and potentially enhance soil carbon storage in semiarid ecosystems. For all seven hydrolytic enzymes examined as well as heterotrophic respiration, there was no consistent or significant response to experimental warming, regardless of seasonal climatic and soil moisture variation. The enzyme results observed here are consistent with the few other experimental results for warming in semiarid ecosystems and indicate that the controls over soil

  17. The effect of different nutrient sources on biomass production of ...

    African Journals Online (AJOL)

    The effect of various organic, inorganic and complex compounds on the biomass production (mycelial dry weight) of Lepiota procera, a Nigerian edible higher fungus was investigated. Among the seventeen carbon compounds tested, mannose enhanced the best biomass yield. This was followed in order by glucose, ...

  18. Thalassic biogas production from sea wrack biomass using different microbial seeds: cow manure, marine sediment and sea wrack-associated microflora.

    Science.gov (United States)

    Marquez, Gian Powell B; Reichardt, Wolfgang T; Azanza, Rhodora V; Klocke, Michael; Montaño, Marco Nemesio E

    2013-04-01

    Sea wrack (dislodged sea grasses and seaweeds) was used in biogas production. Fresh water scarcity in island communities where sea wrack could accumulate led to seawater utilization as liquid substrate. Three microbial seeds cow manure (CM), marine sediment (MS), and sea wrack-associated microflora (SWA) were explored for biogas production. The average biogas produced were 2172±156 mL (MS), 1223±308 mL (SWA) and 551±126 mL (CM). Though methane potential (396.9 mL(CH4) g(-1) volatile solid) computed from sea wrack proximate values was comparable to other feedstocks, highest methane yield was low (MS=94.33 mL(CH4) g(-1) VS). Among the microbial seeds, MS proved the best microbial source in utilizing sea wrack biomass and seawater. However, salinity (MS=42‰) observed exceeded average seawater salinity (34‰). Hence, methanogenic activity could have been inhibited. This is the first report on sea wrack biomass utilization for thalassic biogas production. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. New paradigms for Salmonella source attribution based on microbial subtyping.

    Science.gov (United States)

    Mughini-Gras, Lapo; Franz, Eelco; van Pelt, Wilfrid

    2018-05-01

    Microbial subtyping is the most common approach for Salmonella source attribution. Typically, attributions are computed using frequency-matching models like the Dutch and Danish models based on phenotyping data (serotyping, phage-typing, and antimicrobial resistance profiling). Herewith, we critically review three major paradigms facing Salmonella source attribution today: (i) the use of genotyping data, particularly Multi-Locus Variable Number of Tandem Repeats Analysis (MLVA), which is replacing traditional Salmonella phenotyping beyond serotyping; (ii) the integration of case-control data into source attribution to improve risk factor identification/characterization; (iii) the investigation of non-food sources, as attributions tend to focus on foods of animal origin only. Population genetics models or simplified MLVA schemes may provide feasible options for source attribution, although there is a strong need to explore novel modelling options as we move towards whole-genome sequencing as the standard. Classical case-control studies are enhanced by incorporating source attribution results, as individuals acquiring salmonellosis from different sources have different associated risk factors. Thus, the more such analyses are performed the better Salmonella epidemiology will be understood. Reparametrizing current models allows for inclusion of sources like reptiles, the study of which improves our understanding of Salmonella epidemiology beyond food to tackle the pathogen in a more holistic way. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Radiocesium storage in soil microbial biomass of undisturbed alpine meadow soils and its relation to 137Cs soil-plant transfer

    International Nuclear Information System (INIS)

    Stemmer, Michael; Hromatka, Angelika; Lettner, Herbert; Strebl, Friederike

    2005-01-01

    This study focuses on radiocesium storage in soil microbial biomass of undisturbed alpine meadow sites and its relation to the soil-to-plant transfer. Soil and plant samples were taken in August 1999 from an altitude transect (800-1600 m.a.s.l.) at Gastein valley, Austria. Soil samples were subdivided into 3-cm layers for analyses of total, K 2 SO 4 -extractable and microbially stored 137 Cs. Microbial biomass was measured by the fumigation extraction method, and fungal biomass was quantified using ergosterol as biomarker molecule. In general, the quantity of 137 Cs stored in the living soil microbial biomass was relatively small. At the high-altitude meadows, showing high amounts of fungal biomass, microbially stored 137 Cs amounted to 0.64 ± 0.14 kBq m -2 which corresponds to about 1.2-2.7% of the total 137 Cs soil inventory. At lower altitudes, microbial 137 Cs content was distinctly smaller and in most cases not measurable at all using the fumigation extraction method. However, a positive correlation between the observed soil-to-plant aggregated transfer factor, microbially stored 137 Cs and fungal biomass was found, which indicates a possible role of fungal biomass in the storage and turnover of 137 Cs in soils and in the 137 Cs uptake by plants

  1. Generation of Electricity and Analysis of Microbial Communities in Wheat Straw Biomass-Powered Microbial Fuel Cells

    DEFF Research Database (Denmark)

    Zhang, Yifeng; Min, Booki; Huang, L.

    2009-01-01

    Electricity generation from wheat straw hydrolysate and the microbial ecology of electricity producing microbial communities developed in two chamber microbial fuel cells (MFCs) were investigated. Power density reached 123 mW/m2 with an initial hydrolysate concentration of 1000 mg-COD/L while...

  2. Biomass Burning Emissions of Black Carbon from African Sources

    Science.gov (United States)

    Aiken, A. C.; Leone, O.; Nitschke, K. L.; Dubey, M. K.; Carrico, C.; Springston, S. R.; Sedlacek, A. J., III; Watson, T. B.; Kuang, C.; Uin, J.; McMeeking, G. R.; DeMott, P. J.; Kreidenweis, S. M.; Robinson, A. L.; Yokelson, R. J.; Zuidema, P.

    2016-12-01

    Biomass burning (BB) emissions are a large source of carbon to the atmosphere via particles and gas phase species. Carbonaceous aerosols are emitted along with gas-phase carbon monoxide (CO) and carbon dioxide (CO2) that can be used to determine particulate emission ratios and modified combustion efficiencies. Black carbon (BC) aerosols are potentially underestimated in global models and are considered to be one of the most important global warming factors behind CO2. Half or more BC in the atmosphere is from BB, estimated at 6-9 Tg/yr (IPCC, 5AR) and contributing up to 0.6 W/m2 atmospheric warming (Bond et al., 2013). With a potential rise in drought and extreme events in the future due to climate change, these numbers are expected to increase. For this reason, we focus on BC and organic carbon aerosol species that are emitted from forest fires and compare their emission ratios, physical and optical properties to those from controlled laboratory studies of single-source BB fuels to understand BB carbonaceous aerosols in the atmosphere. We investigate BC in concentrated BB plumes as sampled from the new U.S. DOE ARM Program campaign, Layered Atlantic Smoke Interactions with Clouds (LASIC). The ARM Aerosol Mobile Facility 1 (AMF1) and Mobile Aerosol Observing System (MAOS) are currently located on Ascension Island in the South Atlantic Ocean, located midway between Angola and Brazil. The location was chosen for sampling maximum aerosol outflow from Africa. The far-field aged BC from LASIC is compared to BC from indoor generation from single-source fuels, e.g. African grass, sampled during Fire Lab At Missoula Experiments IV (FLAME-IV). BC is measured with a single-particle soot photometer (SP2) alongside numerous supporting instrumentation, e.g. particle counters, CO and CO2 detectors, aerosol scattering and absorption measurements, etc. FLAME-IV includes both direct emissions and well-mixed aerosol samples that have undergone dilution, cooling, and condensation. BC

  3. Phosphorus uptake by decomposing leaf detritus: effect of microbial biomass and activity

    Energy Technology Data Exchange (ETDEWEB)

    Mulholland, P J; Elwood, J W; Newbold, J D; Webster, J R; Ferren, L A; Perkins, R E

    1984-12-01

    The dominant energy source in small woodland streams is the allochthonous input of leaves. Utilization of this energy source by stream biota establishes the patterns of secondary productivity and nutrient uptake in these ecosystems. Although leaf inputs support much of the production of macroinvertebrates and higher consumers in streams, microbes are the critical link between these organisms and the leaf resource, much of which is undigestible by higher organisms. A number of studies have indicated that stream macroinvertebrates preferentially select leaves with greater levels of microbial activity. Rates of microbial activity associated with decomposing leaves were shown to be dependent on the supply of P in one woodland stream. In other streams, leaf decomposition has been shown to be nutrient limited as well. Thus, as in many other ecosystems, maintenance of high levels of production in streams is dependent on retention and efficient recycling of nutrients. Uptake of P by microbes colonizing leaves is an important mechanism for nutrient retention in small woodland streams. In these systems, numerous debris collections efficiently retard downstream movement of particulate materials, especially decomposing leaves. Uptake of dissolved, easily transportable forms of P by microbes attached to decomposing leaves increases P retention in streams. The more rapid the rate of P uptake onto decomposing leaves for a given P supply, the shorter the P uptake length and the more times an atom of P is utilized within a given stream reach. In this study the authors examined the temporal patterns of P uptake during the early stages of leaf decomposition in streams. Patterns of P uptake were compared to patterns of other measurements of microbial activity to identify the effect of microbial succession or conditioning of leaves on P uptake. 22 references, 1 figure, 2 tables.

  4. Respiration, microbial biomass and soil phosphatase activity in two agroecosystems and one forest in Turrialba, Costa Rica

    Directory of Open Access Journals (Sweden)

    Wuellins Durango

    2015-06-01

    Full Text Available In order to evaluate some microbiological and biochemical characteristics, a comparative study was carried out, as related to 3 different land uses in Ultisols located in Grano de Oro, Turrialba, Costa Rica. Three soil management systems were selected (two agroecosystems, coffee and coffee-banana and forest. In each farm, 4 composite soil samples were collected, on which microbial biomass and respiration, and phosphatase enzyme activity analysis were performed. The microbial biomass in forest was statistically higher (423 mg C kg-1 compared to those in agroecosystems coffee and coffee-banana (77 and 111 mg C kg-1 respectively. Microbial respiration did not show differences due to land management (580, 560 and 570 μg CO2 g-1.day-1 in coffee, coffee-banana and forest systems, respectively. It was also determined that the enzyme phosphatase activity in forest soils was statistically higher (4432 μg p-NP g-1.h-1. The data suggest that soil conditions in the forest favor greater microbial activity and phosphatase biomass, as compared to agricultural systems.

  5. Soil microbial species loss affects plant biomass and survival of an introduced bacterial strain, but not inducible plant defences.

    Science.gov (United States)

    Kurm, Viola; van der Putten, Wim H; Pineda, Ana; Hol, W H Gera

    2018-02-12

    Plant growth-promoting rhizobacteria (PGPR) strains can influence plant-insect interactions. However, little is known about the effect of changes in the soil bacterial community in general and especially the loss of rare soil microbes on these interactions. Here, the influence of rare soil microbe reduction on induced systemic resistance (ISR) in a wild ecotype of Arabidopsis thaliana against the aphid Myzus persicae was investigated. To create a gradient of microbial abundances, soil was inoculated with a serial dilution of a microbial community and responses of Arabidopsis plants that originated from the same site as the soil microbes were tested. Plant biomass, transcription of genes involved in plant defences, and insect performance were measured. In addition, the effects of the PGPR strain Pseudomonas fluorescens SS101 on plant and insect performance were tested under the influence of the various soil dilution treatments. Plant biomass showed a hump-shaped relationship with soil microbial community dilution, independent of aphid or Pseudomonas treatments. Both aphid infestation and inoculation with Pseudomonas reduced plant biomass, and led to downregulation of PR1 (salicylic acid-responsive gene) and CYP79B3 (involved in synthesis of glucosinolates). Aphid performance and gene transcription were unaffected by soil dilution. Neither the loss of rare microbial species, as caused by soil dilution, nor Pseudomonas affect the resistance of A. thaliana against M. persicae. However, both Pseudomonas survival and plant biomass respond to rare species loss. Thus, loss of rare soil microbial species can have a significant impact on both above- and below-ground organisms. © The Author(s) 2018. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. The potential of the Malaysian oil palm biomass as a renewable energy source

    International Nuclear Information System (INIS)

    Loh, Soh Kheang

    2017-01-01

    Highlights: • An energy resource data for oil palm biomass is generated. • The data encompasses crucial fuel and physicochemical characteristics. • These characteristics guide on biomass behaviors and technology selection. • Oil palm biomass is advantageous in today’s energy competitive markets. • Overall, it is a green alternative for biorefinery establishment. - Abstract: The scarcity of conventional energy such as fossil fuels (which will lead to eventual depletion) and the ever-increasing demand for new energy sources have resulted in the world moving into an era of renewable energy (RE) and energy efficiency. The Malaysian oil palm industry has been one of the largest contributor of lignocellulosic biomass, with more than 90% of the country’s total biomass deriving from 5.4 million ha of oil palms. Recent concerns on accelerating replanting activity, improving oil extraction rate, expanding mill capacity, etc. are expected to further increase the total oil palm biomass availability in Malaysia. This situation has presented a huge opportunity for the utilization of oil palm biomass in various applications including RE. This paper characterizes the various forms of oil palm biomass for their important fuel and other physicochemical properties, and assesses this resource data in totality – concerning energy potential, the related biomass conversion technologies and possible combustion-related problems. Overall, oil palm biomass possesses huge potential as one of the largest alternative energy sources for commercial exploitation.

  7. Molecular characterization of bacteriophages for microbial source tracking in Korea.

    Science.gov (United States)

    Lee, Jung Eun; Lim, Mi Young; Kim, Sei Yoon; Lee, Sunghee; Lee, Heetae; Oh, Hyun-Myung; Hur, Hor-Gil; Ko, Gwangpyo

    2009-11-01

    We investigated coliphages from various fecal sources, including humans and animals, for microbial source tracking in South Korea. Both somatic and F+-specific coliphages were isolated from 43 fecal samples from farms, wild animal habitats, and human wastewater plants. Somatic coliphages were more prevalent and abundant than F+ coliphages in all of the tested fecal samples. We further characterized 311 F+ coliphage isolates using RNase sensitivity assays, PCR and reverse transcription-PCR, and nucleic acid sequencing. Phylogenetic analyses were performed based on the partial nucleic acid sequences of 311 F+ coliphages from various sources. F+ RNA coliphages were most prevalent among geese (95%) and were least prevalent in cows (5%). Among the genogroups of F+ RNA coliphages, most F+ coliphages isolated from animal fecal sources belonged to either group I or group IV, and most from human wastewater sources were in group II or III. Some of the group I coliphages were present in both human and animal source samples. F+ RNA coliphages isolated from various sources were divided into two main clusters. All F+ RNA coliphages isolated from human wastewater were grouped with Qbeta-like phages, while phages isolated from most animal sources were grouped with MS2-like phages. UniFrac significance statistical analyses revealed significant differences between human and animal bacteriophages. In the principal coordinate analysis (PCoA), F+ RNA coliphages isolated from human waste were distinctively separate from those isolated from other animal sources. However, F+ DNA coliphages were not significantly different or separate in the PCoA. These results demonstrate that proper analysis of F+ RNA coliphages can effectively distinguish fecal sources.

  8. Multiple approaches to microbial source tracking in tropical northern Australia

    KAUST Repository

    Neave, Matthew

    2014-09-16

    Microbial source tracking is an area of research in which multiple approaches are used to identify the sources of elevated bacterial concentrations in recreational lakes and beaches. At our study location in Darwin, northern Australia, water quality in the harbor is generally good, however dry-season beach closures due to elevated Escherichia coli and enterococci counts are a cause for concern. The sources of these high bacteria counts are currently unknown. To address this, we sampled sewage outfalls, other potential inputs, such as urban rivers and drains, and surrounding beaches, and used genetic fingerprints from E. coli and enterococci communities, fecal markers and 454 pyrosequencing to track contamination sources. A sewage effluent outfall (Larrakeyah discharge) was a source of bacteria, including fecal bacteria that impacted nearby beaches. Two other treated effluent discharges did not appear to influence sites other than those directly adjacent. Several beaches contained fecal indicator bacteria that likely originated from urban rivers and creeks within the catchment. Generally, connectivity between the sites was observed within distinct geographical locations and it appeared that most of the bacterial contamination on Darwin beaches was confined to local sources.

  9. Hydrothermal conversion of biomass to liquid energy sources; Hydrothermale Konversion von Biomasse zu fluessigen Energietraegern

    Energy Technology Data Exchange (ETDEWEB)

    Kroeger, Michael; Peters, Mario; Klemm, Marco; Nelles, Michael [Deutsches Biomasseforschungszentrum (DBFZ) gemeinnuetzige GmbH, Leipzig (Germany)

    2013-10-01

    Beside thermo-chemical processes like pyrolysis, torrefaction and gasification another process group called hydrothermal conversion of biomass comes into the focus of research and development. Especially for wet biomass this process has several advantages: as the reaction medium is water wet biomass not needs to be dried. Beside the reaction pathways, which are still not completely understood, it is important to investigate reactor concepts. That gives the possibility to continuously process the given biomass to deduce specific process conditions for the production of chemicals and fuels. Experiments were conducted in a newly developed tubular reactor at temperatures from 150 to 270 C and reaction times from 1 to 6 min. By studying the HPLC analysis of the liquid products the formation and degradation of several products which may be utilized as base materials for chemicals and fuels (furfural, 5-HMF etc.) was conducted. The experiments illustrate the possibility to influence product composition to a certain extend only by varying temperature and time of the hydrothermal process. That could result in an economic and feasible way to produce intermediate chemicals from biomass. In a second step these product analysis will be used to develop catalysts and investigate the possibilities of in-situ-hydrogenation and synthesis of further valuable chemicals and fuels. (orig.)

  10. Root carbon decomposition and microbial biomass response at different soil depths

    Science.gov (United States)

    Rumpel, C.

    2012-12-01

    The relationship between root litter addition and soil organic matter (SOM) formation in top- versus subsoils is unknown. The aim of this study was to investigate root litter decomposition and stabilisation in relation to microbial parameters in different soil depths. Our conceptual approach included incubation of 13C-labelled wheat roots at 30, 60 and 90 cm soil depth for 36 months under field conditions. Quantitative root carbon contribution to SOM was assessed, changes of bulk root chemistry studied by solid-state 13C NMR spectroscopy and lignin content and composition was assessed after CuO oxidation. Compound-specific isotope analysis allowed to assess the role of root lignin for soil C storage in the different soil depths. Microbial biomass and community structure was determined after DNA extraction. After three years of incubation, O-alkyl C most likely assigned to polysaccharides decreased in all soil depth compared to the initial root material. The degree of root litter decomposition assessed by the alkyl/O-alkyl ratio decreased with increasing soil depth, while aryl/O-alkyl ratio was highest at 60 cm depth. Root-derived lignin showed depth specific concentrations (30 fungi contribution increased after root litter addition. Their community structure changed after root litter addition and showed horizon specific dynamics. Our study shows that root litter addition can contribute to C storage in subsoils but did not influence C storage in topsoil. We conclude that specific conditions of single soil horizons have to be taken into account if root C dynamics are to be fully understood.

  11. Biomass

    Science.gov (United States)

    Bernard R. Parresol

    2001-01-01

    Biomass, the contraction for biological mass, is the amount of living material provided by a given area or volume of the earth's surface, whether terrestrial or aquatic. Biomass is important for commercial uses (e.g., fuel and fiber) and for national development planning, as well as for scientific studies of ecosystem productivity, energy and nutrient flows, and...

  12. Gut Microbial Glycerol Metabolism as an Endogenous Acrolein Source

    Directory of Open Access Journals (Sweden)

    Jianbo Zhang

    2018-01-01

    Full Text Available Acrolein is a highly reactive electrophile causing toxic effects, such as DNA and protein adduction, oxidative stress, endoplasmic reticulum stress, immune dysfunction, and membrane damage. This Opinion/Hypothesis provides an overview of endogenous and exogenous acrolein sources, acrolein’s mode of action, and its metabolic fate. Recent reports underpin the finding that gut microbial glycerol metabolism leading to the formation of reuterin is an additional source of endogenous acrolein. Reuterin is an antimicrobial multicomponent system consisting of 3-hydroxypropionaldehyde, its dimer and hydrate, and also acrolein. The major conclusion is that gut microbes can metabolize glycerol to reuterin and that this transformation occurs in vivo. Given the known toxicity of acrolein, the observation that acrolein is formed in the gut necessitates further investigations on functional relevance for gut microbiota and the host.

  13. Carbon use efficiency (CUE) and biomass turnover of soil microbial communities as affected by bedrock, land management and soil temperature and moisture

    Science.gov (United States)

    Zheng, Qing; Hu, Yuntao; Richter, Andreas; Wanek, Wolfgang

    2017-04-01

    Soil microbial carbon use efficiency (CUE), defined as the proportion of organic C taken up that is allocated to microbial growth, represents an important synthetic representation of microbial community C metabolism that describes the flux partitioning between microbial respiration and growth. Therefore, studying microbial CUE is critical for the understanding of soil C cycling. Microbial CUE is thought to vary with environmental conditions (e.g. temperature and soil moisture). Microbial CUE is thought to decrease with increasing temperature and declining soil moisture, as the latter may trigger stress responses (e.g. the synthesis of stress metabolites), which may consequently lower microbial community CUE. However, these effects on microbial CUE have not been adequately measured so far due to methodological restrictions. The most widely used methods for microbial CUE estimation are based on tracing 13C-labeled substrates into microbial biomass and respiratory CO2, approaches that are known to overestimate microbial CUE of native organic matter in soil. Recently, a novel substrate-independent approach based on the measurement of (i) respiration rates and (ii) the incorporation rates of 18O from labelled water into newly formed microbial DNA has been developed in our laboratory for measuring microbial CUE. This approach overcomes the shortcomings of previously used methods and has already been shown to yield realistic estimations of soil microbial CUE. This approach can also be applied to concurrently measure microbial biomass turnover rates, which also influence the sequestration of soil organic C. Microbial turnover rates are also thought to be impacted by environmental factors, but rarely have been directly measured so far. Here, we aimed at determining the short-term effects of environmental factors (soil temperature and soil moisture) on microbial CUE and microbial biomass turnover rates based on the novel 18O approach. Soils from three land-use types (arable

  14. BIOMASS UTILIZATION AS A RENEVABLE ENERGY SOURCE IN POLISH POWER INDUSTRY – CURRENT STATUS AND PERSPECTIVES

    Directory of Open Access Journals (Sweden)

    Beata Gołuchowska

    2015-06-01

    Full Text Available The depletion of the conventional energy sources, as well as the degradation and pollution of the environment by the exploitation of fossil fuels caused the development of renewable energy sources (RES, including biomass. In Poland, biomass is the most popular renewable energy source, which is closely related to the obligations associated with the membership in the EU. Biomass is the oldest renewable energy source, and its potential, diversity and polymorphism place it over other sources. Besides, the improvement in its parameters, including an increase in its calorific value, resulted in increasing use of biomass as energy source. In the electric power industry biomass is applied in the process of co-combustion with coal. This process may contribute, inter alia, to the reduction in the emissions of carbon, nitrogen and sulfur oxides. The article presents the characteristics of the biomass burned in power boilers of one of the largest Polish power plants, located in Opole Province (Southern Poland. Besides, the impact of biomass on the installation of co-combustion, as well as the advantages and disadvantages of the co-combustion process not only in technological, but also environmental, economic and social aspects were described.

  15. The Impact of Extreme Weather Events on Dissolved Organic Matter and Microbial Biomass of chernozem soils

    Science.gov (United States)

    Müller, Ann-Christin; Blagodatskaya, Evgenia

    2017-04-01

    The aim of this experiment was to study the impact of the extreme weather events freezing-thawing and drying-rewetting on C-, N- and P-dynamics in dissolved organic matter and microbial biomass. The three variants of a chernozem soil (Voronezh region, Russia) are (1) fertilized maize cropping, (2) unfertilized maize cropping and (3) a bare fallow. After both abiotic perturbations the respiration rates were generally lower in the freezing-thawing than in the drying-rewetting treatment, due to the lower temperature. The elevated respiration came along with the decay of organic matter, which was also manifested in increased mineralization of C, N and P immediately after rewetting. However, freezing-thawing had significantly less impact on C-, N- and P-mobilization. We conclude that drying-rewetting leads to an initially increased mobilization of C, N and P, which becomes obvious as increased amounts of DOM immediately after rewetting. Freezing-thawing does not affect mobilization in the same way. There, only an increased mobilization of C can be observed. Especially concerning N and P, the reaction is dependent on the form of use/cropping in both treatments.

  16. [Study on soil enzyme activities and microbial biomass carbon in greenland irrigated with reclaimed water].

    Science.gov (United States)

    Pan, Neng; Hou, Zhen-An; Chen, Wei-Ping; Jiao, Wen-Tao; Peng, Chi; Liu, Wen

    2012-12-01

    The physicochemical properties of soils might be changed under the long-term reclaimed water irrigation. Its effects on soil biological activities have received great attentions. We collected surface soil samples from urban green spaces and suburban farmlands of Beijing. Soil microbial biomass carbon (SMBC), five types of soil enzyme activities (urease, alkaline phosphatase, invertase, dehydrogenase and catalase) and physicochemical indicators in soils were measured subsequently. SMBC and enzyme activities from green land soils irrigated with reclaimed water were higher than that of control treatments using drinking water, but the difference is not significant in farmland. The SMBC increased by 60.1% and 14.2% than those control treatments in 0-20 cm soil layer of green land and farmland, respectively. Compared with their respective controls, the activities of enzymes in 0-20 cm soil layer of green land and farmland were enhanced by an average of 36.7% and 7.4%, respectively. Investigation of SMBC and enzyme activities decreased with increasing of soil depth. Significantly difference was found between 0-10 cm and 10-20 cm soil layer in green land. Soil biological activities were improved with long-term reclaimed water irrigation in Beijing.

  17. Ecological Insights into the Dynamics of Plant Biomass-Degrading Microbial Consortia.

    Science.gov (United States)

    Jiménez, Diego Javier; Dini-Andreote, Francisco; DeAngelis, Kristen M; Singer, Steven W; Salles, Joana Falcão; van Elsas, Jan Dirk

    2017-10-01

    Plant biomass (PB) is an important resource for biofuel production. However, the frequent lack of efficiency of PB saccharification is still an industrial bottleneck. The use of enzyme cocktails produced from PB-degrading microbial consortia (PB-dmc) is a promising approach to optimize this process. Nevertheless, the proper use and manipulation of PB-dmc depends on a sound understanding of the ecological processes and mechanisms that exist in these communities. This Opinion article provides an overview of arguments as to how spatiotemporal nutritional fluxes influence the successional dynamics and ecological interactions (synergism versus competition) between populations in PB-dmc. The themes of niche occupancy, 'sugar cheaters', minimal effective consortium, and the Black Queen Hypothesis are raised as key subjects that foster our appraisal of such systems. Here we provide a conceptual framework that describes the critical topics underpinning the ecological basis of PB-dmc, giving a solid foundation upon which further prospective experimentation can be developed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Grasslands and Croplands Have Different Microbial Biomass Carbon Levels per Unit of Soil Organic Carbon

    Directory of Open Access Journals (Sweden)

    Terence P. McGonigle

    2017-07-01

    Full Text Available Primarily using cropped systems, previous studies have reported a positive linear relationship between microbial biomass carbon (MBC and soil organic carbon (SOC. We conducted a meta-analysis to explore this relationship separately for grasslands and croplands using available literature. Studies were limited to those using fumigation–extraction for MBC for field samples. Trials were noted separately where records were distinct in space or time. Grasslands were naturally occurring, restored, or seeded. Cropping systems were typical of the temperate zone. MBC had a positive linear response to increasing SOC that was significant in both grasslands (p < 0.001; r2 = 0.76 and croplands (p < 0.001; r2 = 0.48. However, MBC increased 2.5-fold more steeply per unit of increasing SOC for grassland soils, as compared to the corresponding response in cropland soils. Expressing MBC as a proportion of SOC across the regression overall, slopes corresponded to 2.7% for grasslands and 1.1% for croplands. The slope of the linear relationship for grasslands was significantly (p = 0.0013 steeper than for croplands. The difference between the two systems is possibly caused by a greater proportion of SOC in grasslands being active rather than passive, relative to that in croplands, with that active fraction promoting the formation of MBC.

  19. The desorption of Phosphorous (32 P) fixed on iron and aluminum oxy-hydroxide surfaces by the soil microbial biomass

    International Nuclear Information System (INIS)

    Araujo, Lilian Maria Cesar de.

    1995-02-01

    This work determines whether the soil microbial biomass, with an ample supply of available C, can utilize P adsorber in the surfaces of oxy-hydroxides of Fe or Al of soil-P deficient soils. To simulate the surfaces of the natural Fe and Al compounds, synthetic oxy-hydroxides of Fe and Al, impregnated in strips of filter paper, and containing P tagged with 32 P, were used. (author). 60 refs., 7 figs., 7 tabs

  20. Genome-centric metatranscriptomes and ecological roles of the active microbial populations during cellulosic biomass anaerobic digestion.

    Science.gov (United States)

    Jia, Yangyang; Ng, Siu-Kin; Lu, Hongyuan; Cai, Mingwei; Lee, Patrick K H

    2018-01-01

    Although anaerobic digestion for biogas production is used worldwide in treatment processes to recover energy from carbon-rich waste such as cellulosic biomass, the activities and interactions among the microbial populations that perform anaerobic digestion deserve further investigations, especially at the population genome level. To understand the cellulosic biomass-degrading potentials in two full-scale digesters, this study examined five methanogenic enrichment cultures derived from the digesters that anaerobically digested cellulose or xylan for more than 2 years under 35 or 55 °C conditions. Metagenomics and metatranscriptomics were used to capture the active microbial populations in each enrichment culture and reconstruct their meta-metabolic network and ecological roles. 107 population genomes were reconstructed from the five enrichment cultures using a differential coverage binning approach, of which only a subset was highly transcribed in the metatranscriptomes. Phylogenetic and functional convergence of communities by enrichment condition and phase of fermentation was observed for the highly transcribed populations in the metatranscriptomes. In the 35 °C cultures grown on cellulose, Clostridium cellulolyticum -related and Ruminococcus -related bacteria were identified as major hydrolyzers and primary fermenters in the early growth phase, while Clostridium leptum -related bacteria were major secondary fermenters and potential fatty acid scavengers in the late growth phase. While the meta-metabolism and trophic roles of the cultures were similar, the bacterial populations performing each function were distinct between the enrichment conditions. Overall, a population genome-centric view of the meta-metabolism and functional roles of key active players in anaerobic digestion of cellulosic biomass was obtained. This study represents a major step forward towards understanding the microbial functions and interactions at population genome level during the

  1. Abrolhos bank reef health evaluated by means of water quality, microbial diversity, benthic cover, and fish biomass data.

    Directory of Open Access Journals (Sweden)

    Thiago Bruce

    Full Text Available The health of the coral reefs of the Abrolhos Bank (Southwestern Atlantic was characterized with a holistic approach using measurements of four ecosystem components: (i inorganic and organic nutrient concentrations, [1] fish biomass, [1] macroalgal and coral cover and (iv microbial community composition and abundance. The possible benefits of protection from fishing were particularly evaluated by comparing sites with varying levels of protection. Two reefs within the well-enforced no-take area of the National Marine Park of Abrolhos (Parcel dos Abrolhos and California were compared with two unprotected coastal reefs (Sebastião Gomes and Pedra de Leste and one legally protected but poorly enforced coastal reef (the "paper park" of Timbebas Reef. The fish biomass was lower and the fleshy macroalgal cover was higher in the unprotected reefs compared with the protected areas. The unprotected and protected reefs had similar seawater chemistry. Lower vibrio CFU counts were observed in the fully protected area of California Reef. Metagenome analysis showed that the unprotected reefs had a higher abundance of archaeal and viral sequences and more bacterial pathogens, while the protected reefs had a higher abundance of genes related to photosynthesis. Similar to other reef systems in the world, there was evidence that reductions in the biomass of herbivorous fishes and the consequent increase in macroalgal cover in the Abrolhos Bank may be affecting microbial diversity and abundance. Through the integration of different types of ecological data, the present study showed that protection from fishing may lead to greater reef health. The data presented herein suggest that protected coral reefs have higher microbial diversity, with the most degraded reef (Sebastião Gomes showing a marked reduction in microbial species richness. It is concluded that ecological conditions in unprotected reefs may promote the growth and rapid evolution of opportunistic

  2. Oil palm biomass as a sustainable energy source: A Malaysian case study

    International Nuclear Information System (INIS)

    Shuit, S.H.; Tan, K.T.; Lee, K.T.; Kamaruddin, A.H.

    2009-01-01

    It has been widely accepted worldwide that global warming is by far the greatest threat and challenge in the new millennium. In order to stop global warming and to promote sustainable development, renewable energy is a perfect solution to achieve both targets. Presently million hectares of land in Malaysia is occupied with oil palm plantation generating huge quantities of biomass. In this context, biomass from oil palm industries appears to be a very promising alternative as a source of raw materials including renewable energy in Malaysia. Thus, this paper aims to present current scenario of biomass in Malaysia covering issues on availability and sustainability of feedstock as well as current and possible utilization of oil palm biomass. This paper will also discuss feasibility of some biomass conversion technologies and some ongoing projects in Malaysia related to utilization of oil palm biomass as a source of renewable energy. Based on the findings presented, it is definitely clear that Malaysia has position herself in the right path to utilize biomass as a source of renewable energy and this can act as an example to other countries in the world that has huge biomass feedstock. (author)

  3. SOCIAL AND ETHICAL CHALLENGES OF USING BIOMASS - A RENEWABLE ENERGY SOURCE

    Directory of Open Access Journals (Sweden)

    Mihaela BOBOC

    2016-12-01

    Full Text Available Biomass, along with other renewable energy sources (solar, wind power, hydropower, etc. is the alternative energy to conventional energy sources. The need of alternative energy sources is given by the increase in energy demand associated with the reduction of conventional sources. They are supplemented by society efforts for reducing the global warming. Thus the biomass use is enthusiastically received and supported by numerous development policies. Nevertheless, the use of biomass to obtain energy involves negative effects on society and also on the environment, generating concerns about the ethics of human actions. All these concerns regarding the biomass use can be prevented and ameliorated by a legislative framework that integrates among the economic and environmental, social and ethical principles. Because without a set of ethical principles aimed at fairness between individuals, social responsibility and also intrinsic value of the biosphere, challenges and problems generated by the use of renewable resources will be intensified

  4. Seasonal and diel variability in dissolved DNA and in microbial biomass and activity in a subtropical estuary

    International Nuclear Information System (INIS)

    Paul, J.H.; Deflaun, M.F.; Jeffrey, W.H.; David, A.W.

    1988-01-01

    Dissolved DNA and microbial biomass and activity parameters were measured over a 15-month period at three stations along a salinity gradient in Tampa Bay, Fla. Dissolved DNA showed seasonal variation, with minimal values in December and January and maximal values in summer months (July and August). This pattern of seasonal variation followed that of particulate DNA and water temperature and did not correlate with bacterioplankton (direct counts and [ 3 H] thymidine incorporation) or phytoplankton (chlorophyll α and 14 CO 2 fixation) biomass and activity. Microautotrophic populations showed maxima in the spring and fall, whereas microheterotrophic activity was greatest in late summer (September). Both autotrophic and heterotrophic microbial activity was greatest at the high estuarine (low salinity) station and lowest at the mouth of the bay (high salinity station), irrespective of season. Dissolved DNA carbon and phosphorus constituted 0.11 +/- 0.05% of the dissolved organic carbon and 6.6 +/- 6.5% of the dissolved organic phosphorus, respectively. Strong diel periodicity was noted in dissolved DNA and in microbial activity in Bayboro Harbor during the dry season. A noon maximum in primary productivity was followed by an 8 p.m. maximum in heterotrophic activity and a midnight maximum in dissolved DNA. This diel periodicity was less pronounced in the wet season, when microbial parameters were strongly influenced by episodic inputs of freshwater

  5. Influence of soil management practices and substrate availability on microbial biomass and its activities in some haplic luvisols

    Energy Technology Data Exchange (ETDEWEB)

    Friedel, Jurgen K [University Hohenheeim, Stuttgart (Germany)

    1996-07-01

    Soil microbial biomass and activities are sensitive indicators of management effects. Higher contents of microbial biomass and higher activities, for example, are found with crop rotations in contrast to bare fallow and mono culture systems. The main reason for these differences is a higher input of crop and root residues in crop rotation systems, leading to more microbial available substrate. The objectives of this study were to describe indices for microbial available substrate in arable soils depending on management practices, and to relate them with soil microbial biomass and activities. At two locations (Muttergarten and hinger Hof near the University of Hohenheim, Stuttgart, SW-Germany), adenosine triphosphate (ATP) contents and microbial activities were measured in haplic Luviosls. As indices for microbial available substrate, water soluble organic carbon compounds in soils were determined and decomposable young soil organic matter was calculated from organic fertilizers and crop and root residues using empirical decomposition functions. Higher ATP contents and microbial activities were observed along with organic fertilization (liquid cattle manure) than with mineral fertilization. Shallow cultivation with a rotary cultivator led to higher values of microbial properties in the upper part of the Ap horizon than ploughing. Soil microbial parameters were higher in plots under a rape-cereals crop rotation, compared to a legumes-cereals crop rotation. Microbial biomass and its activities were related more closely to decomposable young soil organic matter than to soil humus content or to any other soil property. Water soluble organic carbon compounds did not prove as an indicator of microbial available substrate. [Spanish] La biomasa y la actividad microbianas son indicadores sensibles de los efectos del manejo del suelo. Por ejemplo, con la rotacion de cultivos se obtiene un contenido y una actividad mayores de la biomasa microbiana en contraste con el simple

  6. Seasonal variations and effects of nutrient applications on N and P and microbial biomass under two temperate heathland plants

    DEFF Research Database (Denmark)

    Nielsen, Pia Lund; Andresen, Louise Christoffersen; Michelsen, Anders

    2009-01-01

    . The microbial biomass on the other hand was positively related to soil water content in fertilized plots indicating that this was due to an indirect effect of enhanced nutrient availability. Microbial N and P pools were respectively 1000 and 100 times higher than the pool of inorganic N and P, and microbes...... this process. In this study the soil properties under two dominant heathland plants, the dwarf shrub Calluna vulgaris and the grass Deschampsia flexuosa, were investigated, with focus on nutrient content in the organic top soil and soil microbes during the main growing season and effects of nutrient amendments...... therefore may play an important role in regulating plant nutrient supply. Judged from responses of inorganic and microbial N and P concentrations to added N and P, N seemed to limit C. vulgaris and soil microbes below while P seemed to limit D. flexuosa and soil microbes below this species. There were lower...

  7. Microbial biomass and biological activity of soils and soil-like bodies in coastal oases of Antarctica

    Science.gov (United States)

    Nikitin, D. A.; Marfenina, O. E.; Kudinova, A. G.; Lysak, L. V.; Mergelov, N. S.; Dolgikh, A. V.; Lupachev, A. V.

    2017-09-01

    The method of luminescent microscopy has been applied to study the structure of the microbial biomass of soils and soil-like bodies in East (the Thala Hills and Larsemann Hills oases) and West (Cape Burks, Hobbs coast) Antarctica. According to Soil Taxonomy, the studied soils mainly belong to the subgroups of Aquic Haploturbels, Typic Haploturbels, Typic Haplorthels, and Lithic Haplorthels. The major contribution to their microbial biomass belongs to fungi. The highest fungal biomass (up to 790 μg C/g soil) has been found in the soils with surface organic horizons in the form of thin moss/lichen litters, in which the development of fungal mycelium is most active. A larger part of fungal biomass (70-98%) is represented by spores. For the soils without vegetation cover, the accumulation of bacterial and fungal biomass takes place in the horizons under surface desert pavements. In the upper parts of the soils without vegetation cover and in the organic soil horizons, the major part (>60%) of fungal mycelium contains protective melanin pigments. Among bacteria, the high portion (up to 50%) of small filtering forms is observed. A considerable increase (up to 290.2 ± 27 μg C/g soil) in the fungal biomass owing to the development of yeasts has been shown for gley soils (gleyzems) developing from sapropel sediments under subaquatic conditions and for the algal-bacterial mat on the bottom of the lake (920.7 ± 46 μg C/g soil). The production of carbon dioxide by the soils varies from 0.47 to 2.34 μg C-CO2/(g day). The intensity of nitrogen fixation in the studied samples is generally low: from 0.08 to 55.85 ng C2H4/(g day). The intensity of denitrification varies from 0.09 to 19.28 μg N-N2O/(g day).

  8. Planktonic food web structure at a coastal time-series site: I. Partitioning of microbial abundances and carbon biomass

    Science.gov (United States)

    Caron, David A.; Connell, Paige E.; Schaffner, Rebecca A.; Schnetzer, Astrid; Fuhrman, Jed A.; Countway, Peter D.; Kim, Diane Y.

    2017-03-01

    Biogeochemistry in marine plankton communities is strongly influenced by the activities of microbial species. Understanding the composition and dynamics of these assemblages is essential for modeling emergent community-level processes, yet few studies have examined all of the biological assemblages present in the plankton, and benchmark data of this sort from time-series studies are rare. Abundance and biomass of the entire microbial assemblage and mesozooplankton (>200 μm) were determined vertically, monthly and seasonally over a 3-year period at a coastal time-series station in the San Pedro Basin off the southwestern coast of the USA. All compartments of the planktonic community were enumerated (viruses in the femtoplankton size range [0.02-0.2 μm], bacteria + archaea and cyanobacteria in the picoplankton size range [0.2-2.0 μm], phototrophic and heterotrophic protists in the nanoplanktonic [2-20 μm] and microplanktonic [20-200 μm] size ranges, and mesozooplankton [>200 μm]. Carbon biomass of each category was estimated using standard conversion factors. Plankton abundances varied over seven orders of magnitude across all categories, and total carbon biomass averaged approximately 60 μg C l-1 in surface waters of the 890 m water column over the study period. Bacteria + archaea comprised the single largest component of biomass (>1/3 of the total), with the sum of phototrophic protistan biomass making up a similar proportion. Temporal variability at this subtropical station was not dramatic. Monthly depth-specific and depth-integrated biomass varied 2-fold at the station, while seasonal variances were generally web structure and function at this coastal observatory.

  9. Sensitivity of molecular marker-based CMB models to biomass burning source profiles

    Science.gov (United States)

    Sheesley, Rebecca J.; Schauer, James J.; Zheng, Mei; Wang, Bo

    To assess the contribution of sources to fine particulate organic carbon (OC) at four sites in North Carolina, USA, a molecular marker chemical mass balance model (MM-CMB) was used to quantify seasonal contributions for 2 years. The biomass burning contribution at these sites was found to be 30-50% of the annual OC concentration. In order to provide a better understanding of the uncertainty in MM-CMB model results, a biomass burning profile sensitivity test was performed on the 18 seasonal composites. The results using reconstructed emission profiles based on published profiles compared well, while model results using a single source test profile resulted in biomass burning contributions that were more variable. The biomass burning contribution calculated using an average regional profile of fireplace emissions from five southeastern tree species also compared well with an average profile of open burning of pine-dominated forest from Georgia. The standard deviation of the results using different source profiles was a little over 30% of the annual average biomass contributions. Because the biomass burning contribution accounted for 30-50% of the OC at these sites, the choice of profile also impacted the motor vehicle source attribution due to the common emission of elemental carbon and polycyclic aromatic hydrocarbons. The total mobile organic carbon contribution was less effected by the biomass burning profile than the relative contributions from gasoline and diesel engines.

  10. Microbial source tracking and transfer hydrodynamics in rural catchments.

    Science.gov (United States)

    Murphy, Sinead; Bhreathnach, Niamh; O'Flaherty, Vincent; Jordan, Philip; Wuertz, Stefan

    2013-04-01

    In Ireland, bacterial pathogens from continual point source pollution and intermittent pollution from diffuse sources can impact both drinking water supplies and recreational waters. This poses a serious public health threat. Observing and establishing the source of faecal pollution is imperative for the protection of water quality and human health. Traditional culture methods to detect such pollution via faecal indicator bacteria have been widely utilised but do not decipher the source of pollution. To combat this, microbial source tracking, an important emerging molecular tool, is applied to detect host-specific markers in faecally contaminated waters. The aim of this study is to target ruminant and human-specific faecal Bacteroidales and Bacteroides 16S rRNA genes within rural river catchments in Ireland and investigate hydrological transfer dependencies. During storm events and non-storm periods, 1L untreated water samples, taken every 2 hours over a 48-hour time period at the spring (Cregduff) or outlet (Dunleer), and large (5-20L) untreated water samples were collected from two catchment sites. Cregduff is a spring emergence under a grassland karst landscape in Co. Mayo (west coast of Ireland) and Dunleer is a mixed landuse over till soils in Co. Louth (east coast). From a risk assessment point of view, the catchments are very different. Samples were filtered through 0.2µm nitrocellulose filters to concentrate bacterial cells which then underwent chemical extraction of total nucleic acids. Animal and human stool samples were also collected from the catchments to determine assay sensitivity and specificity following nucleic acid extraction. Aquifer response to seasonal events was assessed by monitoring coliforms and E. coli occurrence using the IDEXX Colisure® Quanti Tray®/2000 system in conjunction with chemical and hydrological parameters. Autoanalysers deployed at each catchment monitor multiple water parameters every 10 min such as phosphorus, nitrogen

  11. Microbial fermented tea - a potential source of natural food preservatives

    NARCIS (Netherlands)

    Mo, H.Z.; Yang Zhu, Yang; Chen, Z.M.

    2008-01-01

    Antimicrobial activities of microbial fermented tea are much less known than its health beneficial properties. These antimicrobial activities are generated in natural microbial fermentation process with tea leaves as substrates. The antimicrobial components produced during the fermentation process

  12. Biofilm formation and microbial community analysis of the simulated river bioreactor for contaminated source water remediation.

    Science.gov (United States)

    Xu, Xiang-Yang; Feng, Li-Juan; Zhu, Liang; Xu, Jing; Ding, Wei; Qi, Han-Ying

    2012-06-01

    The start-up pattern of biofilm remediation system affects the biofilm characteristics and operating performances. The objective of this study was to evaluate the performances of the contaminated source water remediation systems with different start-up patterns in view of the pollutants removal performances and microbial community succession. The operating performances of four lab-scale simulated river biofilm reactors were examined which employed different start-up methods (natural enrichment and artificial enhancement via discharging sediment with influent velocity gradient increase) and different bio-fillers (Elastic filler and AquaMats® ecobase). At the same time, the microbial communities of the bioreactors in different phases were analyzed by polymerase chain reaction, denaturing gradient gel electrophoresis, and sequencing. The pollutants removal performances became stable in the four reactors after 2 months' operation, with ammonia nitrogen and permanganate index (COD(Mn)) removal efficiencies of 84.41-94.21% and 69.66-76.60%, respectively. The biomass of mature biofilm was higher in the bioreactors by artificial enhancement than that by natural enrichment. Microbial community analysis indicated that elastic filler could enrich mature biofilm faster than AquaMats®. The heterotrophic bacteria diversity of biofilm decreased by artificial enhancement, which favored the ammonia-oxidizing bacteria (AOB) developing on the bio-fillers. Furthermore, Nitrosomonas- and Nitrosospira-like AOB coexisted in the biofilm, and Pseudomonas sp., Sphaerotilus sp., Janthinobacterium sp., Corynebacterium aurimucosum were dominant in the oligotrophic niche. Artificial enhancement via the combination of sediment discharging and influent velocity gradient increasing could enhance the biofilm formation and autotrophic AOB enrichment in oligotrophic niche.

  13. Microbial Biomass and Activity in Geomorphic Features in Forested and Urban Restored and Degraded Streams

    Science.gov (United States)

    Geomorphic spatial heterogeneity affects sediment denitrification, an anaerobic microbial process that results in the loss of nitrogen (N), and other anaerobic microbial processes such as methanogenesis in urban streams. We measured sediment denitrification potential (DEA), metha...

  14. Afforestation impacts microbial biomass and its natural {sup 13}C and {sup 15}N abundance in soil aggregates in central China

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Junjun; Zhang, Qian; Yang, Fan; Lei, Yao; Zhang, Quanfa; Cheng, Xiaoli, E-mail: xlcheng@fudan.edu.cn

    2016-10-15

    We investigated soil microbial biomass and its natural abundance of δ{sup 13}C and δ{sup 15}N in aggregates (> 2000 μm, 250–2000 μm, 53–250 μm and < 53 μm) of afforested (implementing woodland and shrubland plantations) soils, adjacent croplands and open area (i.e., control) in the Danjiangkou Reservoir area of central China. The afforested soils averaged higher microbial biomass carbon (MBC) and nitrogen (MBN) levels in all aggregates than in open area and cropland, with higher microbial biomass in micro-aggregates (< 250 μm) than in macro-aggregates (> 2000 μm). The δ{sup 13}C of soil microbial biomass was more enriched in woodland soils than in other land use types, while δ{sup 15}N of soil microbial biomass was more enriched compared with that of organic soil in all land use types. The δ{sup 13}C and δ{sup 15}N of microbial biomass were positively correlated with the δ{sup 13}C and δ{sup 15}N of organic soil across aggregates and land use types, whereas the {sup 13}C and {sup 15}N enrichment of microbial biomass exhibited linear decreases with the corresponding C:N ratio of organic soil. Our results suggest that shifts in the natural {sup 13}C and {sup 15}N abundance of microbial biomass reflect changes in the stabilization and turnover of soil organic matter (SOM) and thereby imply that afforestation can greatly impact SOM accumulation over the long-term. - Highlights: • Afforested soils averaged higher microbial biomass in all aggregates than cropland. • Microbial biomass was higher in micro-aggregates than in macro-aggregates. • δ{sup 13}C and δ{sup 15}N of microbe positively correlated with δ{sup 13}C and δ{sup 15}N of organic soil. • {sup 13}C and {sup 15}N enrichment of microbe was negatively related to with soil C:N ratio.

  15. Enhanced conversion of newly-added maize straw to soil microbial biomass C under plastic film mulching and organic manure management

    Science.gov (United States)

    Jin, X.; Filley, T. R.

    2017-12-01

    Management of crop residues using plastic film mulching (PFM) has the potential to improve soil health by accelerating nutrient cycling and facilitating stable C pool production; however, a key aspect of this process—microbial immobilization of residue C—is poorly understood, especially under PFM when combined with different fertilization treatments. A 360-day in situ 13C-tracing technique was used to analyze the contribution and dynamics of microbial biomass C (MBC) to soil organic C (SOC) after 13C-labelled maize straw residue was applied to micro-plot topsoil in a cultivated maize (Zea mays L.) field under 27-year PFM and four fertilization treatments. Over the course of the experiment, MBC content was significantly (P<0.05) higher in treatments of manure (M) and manure plus nitrogen (MN) compared to the no-fertilization (CK) and nitrogen (N) treatments, regardless of PFM. Compared to no PFM controls, PFM enhanced the decomposition of maize straw during summer (Day 60) in the M and MN treatments, exhibiting increases of 93.0% and 28.6% in straw-derived 13C-MBC and 80.4% and 82.9% in 13C-MBC/13C-SOC, respectively. Overall, both PFM and organic manure treatments improved soil fertility through microbe-mediated incorporation of C derived from newly-added maize straw. Our results indicate that microbial growth and activity are affected by the utilization of different C sources and most dramatically during early seasonal transition.

  16. Mold biomass as a potential source of nutrient proteins

    Energy Technology Data Exchange (ETDEWEB)

    Fuska, J; Kollarova, A

    1977-01-01

    In submerged cultures of Penicillium resticulosum, Mycelium sterilium, Gibberella fuiikuroi, and Coprinus species grown for 72 hours in medium containing 5 to 7% sawdust hydrolyzate, 1.28 to 1.45 g of dry biomass per 100 mL of culture was produced with 28.1 to 35.3% total amino acids and 15 to 18% essential amino acids; 80 to 90% of the cellular protein was digestible. Mannose, glucose and galactose of the hydrolyzate were utilized faster than xylose and arabinose.

  17. A Customized DNA Microarray for Microbial Source Tracking ...

    Science.gov (United States)

    It is estimated that more than 160, 000 miles of rivers and streams in the United States are impaired due to the presence of waterborne pathogens. These pathogens typically originate from human and other animal fecal pollution sources; therefore, a rapid microbial source tracking (MST) method is needed to facilitate water quality assessment and impaired water remediation. We report a novel qualitative DNA microarray technology consisting of 453 probes for the detection of general fecal and host-associated bacteria, viruses, antibiotic resistance, and other environmentally relevant genetic indicators. A novel data normalization and reduction approach is also presented to help alleviate false positives often associated with high-density microarray applications. To evaluate the performance of the approach, DNA and cDNA was isolated from swine, cattle, duck, goose and gull fecal reference samples, as well as soiled poultry liter and raw municipal sewage. Based on nonmetric multidimensional scaling analysis of results, findings suggest that the novel microarray approach may be useful for pathogen detection and identification of fecal contamination in recreational waters. The ability to simultaneously detect a large collection of environmentally important genetic indicators in a single test has the potential to provide water quality managers with a wide range of information in a short period of time. Future research is warranted to measure microarray performance i

  18. Microbial Source Tracking in a Watershed Dominated by Swine

    Directory of Open Access Journals (Sweden)

    Joice F. Lubbers

    2010-09-01

    Full Text Available The high concentration of swine production in southeastern North Carolina generates public health concerns regarding the potential transport of pathogens from these production systems to nearby surface waters. The microbial source tracking (MST tool, antibiotic resistance analysis (ARA, was used to identify sources of E. coli in a segment of Six Runs Creek in Sampson County, North Carolina. Among 52 water samples, fecal coliform (FC counts averaged 272.1 ± 181.6 CFU/100 mL. Comparisons of isolates from water samples to an ARA library with an average rate of correct classification (ARCC of 94.3% indicated an average of 64% and 27.1% of 1,961 isolates from Six Runs Creek were associated with lagoon effluent and cattle manure respectively. The potential for aerosol transport of bacteria during lagoon spray events, as well as, the potential for wildlife to serve as a vehicle of transport for bacteria from fields and lagoons to nearby surface waters should be investigated further.

  19. Biomass and pigments production in photosynthetic bacteria wastewater treatment: effects of light sources.

    Science.gov (United States)

    Zhou, Qin; Zhang, Panyue; Zhang, Guangming

    2015-03-01

    This study is aimed at enhancing biomass and pigments production together with pollution removal in photosynthetic bacteria (PSB) wastewater treatment via different light sources. Red, yellow, blue, white LED and incandescent lamp were used. Results showed different light sources had great effects on the PSB. PSB had the highest biomass production, COD removal and biomass yield with red LED. The corresponding biomass, COD removal and biomass yield reached 2580 mg/L, 88.6% and 0.49 mg-biomass/mg-COD-removal, respectively. The hydraulic retention time of wastewater treatment could be shortened to 72 h with red LED. Mechanism analysis showed higher ATP was produced with red LED than others. Light sources could significantly affect the pigments production. The pigments productions were greatly higher with LED than incandescent lamp. Yellow LED had the highest pigments production while red LED produced the highest carotenoid/bacteriochlorophyll ratio. Considering both efficiency and energy cost, red LED was the optimal light source. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Leaf-Cutter Ant Fungus Gardens Are Biphasic Mixed Microbial Bioreactors That Convert Plant Biomass to Polyols with Biotechnological Applications

    Science.gov (United States)

    Somera, Alexandre F.; Lima, Adriel M.; dos Santos-Neto, Álvaro J.; Lanças, Fernando M.

    2015-01-01

    Leaf-cutter ants use plant matter to culture the obligate mutualistic basidiomycete Leucoagaricus gongylophorus. This fungus mediates ant nutrition on plant resources. Furthermore, other microbes living in the fungus garden might also contribute to plant digestion. The fungus garden comprises a young sector with recently incorporated leaf fragments and an old sector with partially digested plant matter. Here, we show that the young and old sectors of the grass-cutter Atta bisphaerica fungus garden operate as a biphasic solid-state mixed fermenting system. An initial plant digestion phase occurred in the young sector in the fungus garden periphery, with prevailing hemicellulose and starch degradation into arabinose, mannose, xylose, and glucose. These products support fast microbial growth but were mostly converted into four polyols. Three polyols, mannitol, arabitol, and inositol, were secreted by L. gongylophorus, and a fourth polyol, sorbitol, was likely secreted by another, unidentified, microbe. A second plant digestion phase occurred in the old sector, located in the fungus garden core, comprising stocks of microbial biomass growing slowly on monosaccharides and polyols. This biphasic operation was efficient in mediating symbiotic nutrition on plant matter: the microbes, accounting for 4% of the fungus garden biomass, converted plant matter biomass into monosaccharides and polyols, which were completely consumed by the resident ants and microbes. However, when consumption was inhibited through laboratory manipulation, most of the plant polysaccharides were degraded, products rapidly accumulated, and yields could be preferentially switched between polyols and monosaccharides. This feature might be useful in biotechnology. PMID:25911490

  1. Effects of nitrogen and phosphorus additions on soil microbial biomass and community structure in two reforested tropical forests.

    Science.gov (United States)

    Liu, Lei; Gundersen, Per; Zhang, Wei; Zhang, Tao; Chen, Hao; Mo, Jiangming

    2015-09-23

    Elevated nitrogen (N) deposition may aggravate phosphorus (P) deficiency in forests in the warm humid regions of China. To our knowledge, the interactive effects of long-term N deposition and P availability on soil microorganisms in tropical replanted forests remain unclear. We conducted an N and P manipulation experiment with four treatments: control, N addition (15 g N m(-2)·yr(-1)), P addition (15 g P m(-2)·yr(-1)), and N and P addition (15 + 15 g N and P m(-2)·yr(-1), respectively) in disturbed (planted pine forest with recent harvests of understory vegetation and litter) and rehabilitated (planted with pine, but mixed with broadleaf returning by natural succession) forests in southern China. Nitrogen addition did not significantly affect soil microbial biomass, but significantly decreased the abundance of gram-negative bacteria PLFAs in both forest types. Microbial biomass increased significantly after P addition in the disturbed forest but not in the rehabilitated forest. No interactions between N and P additions on soil microorganisms were observed in either forest type. Our results suggest that microbial growth in replanted forests of southern China may be limited by P rather than by N, and this P limitation may be greater in disturbed forests.

  2. Nitrogen deposition and management practices increase soil microbial biomass carbon but decrease diversity in Moso bamboo plantations

    Science.gov (United States)

    Li, Quan; Song, Xinzhang; Gu, Honghao; Gao, Fei

    2016-06-01

    Because microbial communities play a key role in carbon (C) and nitrogen (N) cycling, changes in the soil microbial community may directly affect ecosystem functioning. However, the effects of N deposition and management practices on soil microbes are still poorly understood. We studied the effects of these two factors on soil microbial biomass carbon (MBC) and community composition in Moso bamboo plantations using high-throughput sequencing of the 16S rRNA gene. Plantations under conventional (CM) or intensive management (IM) were subjected to one of four N treatments for 30 months. IM and N addition, both separately and in combination, significantly increased soil MBC while decreasing bacterial diversity. However, increases in soil MBC were inhibited when N addition exceeded 60 kg N•ha-1•yr-1. IM increased the relative abundances of Actinobacteria and Crenarchaeota but decreased that of Acidobacteria. N addition increased the relative abundances of Acidobacteria, Crenarchaeota, and Actinobacteria but decreased that of Proteobacteria. Soil bacterial diversity was significantly related to soil pH, C/N ratio, and nitrogen and available phosphorus content. Management practices exerted a greater influence over regulation of the soil MBC and microbial diversity compared to that of N deposition in Moso bamboo plantations.

  3. Abundance and biomass responses of microbial food web components to hydrology and environmental gradients within a floodplain of the River Danube.

    Science.gov (United States)

    Palijan, Goran

    2012-07-01

    This study investigated the relationships of time-dependent hydrological variability and selected microbial food web components. Samples were collected monthly from the Kopački Rit floodplain in Croatia, over a period of 19 months, for analysis of bacterioplankton abundance, cell size and biomass; abundance of heterotrophic nanoflagellates and nanophytoplankton; and concentration of chlorophyll a. Similar hydrological variability at different times of the year enabled partition of seasonal effects from hydrological changes on microbial community properties. The results suggested that, unlike some other studies investigating sites with different connectivity, bacterioplankton abundance, and phytoplankton abundance and biomass increased during lentic conditions. At increasing water level, nanophytoplankton showed lower sensitivity to disturbance in comparison with total phytoplankton biomass: this could prolong autotrophic conditions within the floodplain. Bacterioplankton biomass, unlike phytoplankton, was not impacted by hydrology. The bacterial biomass less affected by hydrological changes can be an important additional food component for the floodplain food web. The results also suggested a mechanism controlling bacterial cell size independent of hydrology, as bacterial cell size was significantly decreased as nanoflagellate abundance increased. Hydrology, regardless of seasonal sucession, has the potential to structure microbial food webs, supporting microbial development during lentic conditions. Conversely, other components appear unaffected by hydrology or may be more strongly controlled by biotic interactions. This research, therefore, adds to understanding on microbial food web interactions in the context of flood and flow pulses in river-floodplain ecosystems.

  4. Importance of biomass energy as alternative to other sources in Turkey

    International Nuclear Information System (INIS)

    Gokcol, Cihan; Dursun, Bahtiyar; Alboyaci, Bora; Sunan, Erkan

    2009-01-01

    Energy plays a vital role in socio-economic development and raising standards of human beings. Turkey is a rapidly growing country; both its population and economy are expanding each year so its energy demand increases correspondingly and this increasing demand has to be met for keeping sustainable development in the economy and raising living conditions of mankind. Although Turkey has many energy sources, it is a big energy importer. Turkey has a lot of potential to supply its own energy, which could be put to use in order to avoid this energy dependence. Additionally, Turkey is a country that has an abundance of renewable energy sources and can essentially provide all energy requirements from indigenous energy sources. Biomass is one of the most promising energy sources considered to be alternative to conventional ones. This paper investigates the importance of biomass energy in Turkey. Additionally, the potential of biomass and its utilization in Turkey are presented in detail. Turkey has always been one of the major agricultural countries of the world. The importance of agriculture is increasing due to biomass energy being a major resource of Turkey. Like many developing countries, Turkey relies on biomass to satisfy much of its energy requirements

  5. Conversion of Wastes into Bioelectricity and Chemicals by Using Microbial Electrochemical Technologies

    KAUST Repository

    Logan, B. E.; Rabaey, K.

    2012-01-01

    Waste biomass is a cheap and relatively abundant source of electrons for microbes capable of producing electrical current outside the cell. Rapidly developing microbial electrochemical technologies, such as microbial fuel cells, are part of a

  6. Linking diagnostic features to soil microbial biomass and respiration in agricultural grassland soil

    NARCIS (Netherlands)

    Richter, A.; Huallacháin, D.O.; Doyle, E.; Clipson, N.; Leeuwen, Van J.P.; Heuvelink, G.B.; Creamer, R.E.

    2018-01-01

    The functional potential of soil ecosystems can be predicted from the activity and abundance of the microbial community in relation to key soil properties. When describing microbial community dynamics, soil physicochemical properties have traditionally been used. The extent of correlations between

  7. Options for cost-effectively reducing atmospheric methane concentrations from anthropogenic biomass sources

    International Nuclear Information System (INIS)

    Roos, K.F.; Jacobs, C.; Orlic, M.

    1993-01-01

    Methane is a major greenhouse gas, second only to carbon dioxide in its contribution to future global warming. Methane concentrations have more than doubled over the last two centuries and continue to rise annually. These increases are largely correlated with increasing human populations. Methane emissions from human related activities currently account for about 70 percent of annual emissions. Of these human related emissions, biomass sources account for about 75 percent and non-biomass sources about 25 percent. Because methane has a shorter lifetime than other major greenhouse gases, efforts to reduce methane emissions may fairly quickly be translated into lower atmospheric concentrations of methane and lower levels of radiative forcing. This fairly quick response would have the benefit of slowing the rate of climate change and hence allow natural ecosystems more time to adapt. Importantly, methane may be cost-effectively reduced from a number of biomass and non-biomass sources in the United States and worldwide. Methane is a valuable fuel, not just a waste by-product, and often systems may be reconfigured to reap the fuel value of the methane and more than justify the necessary expenditures. Such options for reducing methane emission from biomass sources exist for landfills, livestock manures, and ruminant livestock, and have been implemented to varying degrees in countries around the world. However, there are a number of barriers that hinder the more widespread use of technologies, including institutional, financial, regulatory, informational, and other barriers. This paper describes an array of available options that may be cost-effectively implemented to reduce methane emissions from biomass sources. This paper also discusses a number of programs that have been developed in the United States and internationally to promote the implementation of these methane reduction options and overcome existing barriers

  8. Capturing microbial sources distributed in a mixed-use watershed within an integrated environmental modeling workflow

    Science.gov (United States)

    Many watershed models simulate overland and instream microbial fate and transport, but few provide loading rates on land surfaces and point sources to the waterbody network. This paper describes the underlying equations for microbial loading rates associated with 1) land-applied ...

  9. Influence of Inoculation, Nitrogen and Phosphorus Levels on Wheat Growth and Soil Microbial Biomass-N Using 15N Techniques

    International Nuclear Information System (INIS)

    Galal, Y.G.; El-Ghandour, I.A.; Abdel Raouf, A.M.; Osman, M.E.

    2003-01-01

    Pot experiment was carried out with wheat that cultivated in virgin sandy soil and inoculated with Rhizobium (Rh), mycorrhizea (VAM) and mixture of both. The objective of this work was to verify the potential of these inoculum on wheat production, nutrient acquisition and microbial biomass N (MBN) contribution as affected by N and P fertilizers levels. MBN was detected through the fumigation-extraction method. Nitrogen and phosphorus fertilizers were applied at three levels, 0; 25 ppm N and 3.3 ppm P and 50 ppm N and 6.6 ppm P in the form of ( 15 NH 4 ) 2 SO 4 , 5% atom excess and super-phosphate, respectively. The effect of inoculation and chemical fertilizers on dry matter (DM), N and P uptake (shoot and grain) and MBN were traced. The obtained data revealed that the highest DM and N uptake by wheat shoot were recorded with the dual inoculation (Rh + VAM) at the highest level of N and P fertilizers. The highest grain yield was detected with single inoculum of AM fungi while N and P uptake were with dual inoculation at the same rate of fertilizers. Inoculation with Rh either alone or in combination with VAM have a positive and stimulative effect on wheat growth and N and P uptake indicating the possibilities of extending the use of symbiotic microorganisms to be applied with cereals. The fluctuation in the soil microbial biomass N did not gave a chance to recognize, exactly, the impact of inoculation and/or fertilization levels

  10. An open source platform for multi-scale spatially distributed simulations of microbial ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Segre, Daniel [Boston Univ., MA (United States)

    2014-08-14

    The goal of this project was to develop a tool for facilitating simulation, validation and discovery of multiscale dynamical processes in microbial ecosystems. This led to the development of an open-source software platform for Computation Of Microbial Ecosystems in Time and Space (COMETS). COMETS performs spatially distributed time-dependent flux balance based simulations of microbial metabolism. Our plan involved building the software platform itself, calibrating and testing it through comparison with experimental data, and integrating simulations and experiments to address important open questions on the evolution and dynamics of cross-feeding interactions between microbial species.

  11. Effects of Hurricane-Felled Tree Trunks on Soil Carbon, Nitrogen, Microbial Biomass, and Root Length in a Wet Tropical Forest

    Directory of Open Access Journals (Sweden)

    D. Jean Lodge

    2016-11-01

    Full Text Available Decaying coarse woody debris can affect the underlying soil either by augmenting nutrients that can be exploited by tree roots, or by diminishing nutrient availability through stimulation of microbial nutrient immobilization. We analyzed C, N, microbial biomass C and root length in closely paired soil samples taken under versus 20–50 cm away from large trunks of two species felled by Hugo (1989 and Georges (1998 three times during wet and dry seasons over the two years following the study conducted by Georges. Soil microbial biomass, % C and % N were significantly higher under than away from logs felled by both hurricanes (i.e., 1989 and 1998, at all sampling times and at both depths (0–10 and 10–20 cm. Frass from wood boring beetles may contribute to early effects. Root length was greater away from logs during the dry season, and under logs in the wet season. Root length was correlated with microbial biomass C, soil N and soil moisture (R = 0.36, 0.18, and 0.27, respectively; all p values < 0.05. Microbial biomass C varied significantly among seasons but differences between positions (under vs. away were only suggestive. Microbial C was correlated with soil N (R = 0.35. Surface soil on the upslope side of the logs had significantly more N and microbial biomass, likely from accumulation of leaf litter above the logs on steep slopes. We conclude that decaying wood can provide ephemeral resources that are exploited by tree roots during some seasons.

  12. Effects of Nitrogen and Water on Soil Enzyme Activity and Soil Microbial Biomass in Stipa baicalensis Steppe,Inner Mongolia of North China

    Directory of Open Access Journals (Sweden)

    WANG Jie

    2014-06-01

    Full Text Available In this paper, eight nitrogen treatments were applied at 0 g·m -2(N0, 1.5 g·m -2(N15, 3.0 g·m -2(N30, 5.0 g·m -2(N50, 10.0 g·m -2(N100, 15.0 g·m -2(N150, 20.0 g·m -2(N200, 30.0 g·m -2(N300 as NH 4 NO 3 and adding water to simulate summer rainfall of 100 mm, the interactive experiment was set to explore the effects of nitrogen and water addition in Stipa baicalensis steppe on soil nutrients, enzyme activities and soil microbial biomass. The results showed that the nitrogen and water addition changed soil physico-chemical factors obviously, the content of soil total organic carbon, total nitrogen, nitrate nitrogen and ammonium nitrogen increased along with the increasing of application rate of nitrogen, on the contrary, the soil pH value had decreasing trend. Appropriate application of nitrogen could enhance the activity of urease and catalase but decreased the activity of polyphenol oxidase. Nitrogen and water addition had significant effect on soil microbial biomass C and N. Higher level of N fertilizer significantly reduced microbial biomass C, and the microbial biomass N was on the rise with the application rate of nitrogen. The addition of water could slow the inhibition of nitrogen to microorganism and increase the microbial biomass C and N. A closed relationship existed in soil nutrient, activities of soil enzyme and soil microbial biomass C and N. The significantly positive correlation existed between total N, organic C, nitrate N and catalase, significantly negative correlation between nitrate N, ammonium N, total N and polyphenol oxidase. Microbial biomass N was significantly positive correlated with total N, nitrate N, ammonium N, catalase, phosphatase, and was negative correlated with polyphenol oxidase. Microbial biomass C was significantly positive correlated with polyphenol oxidase, and was negative correlated with catalase.

  13. Advanced system demonstration for utilization of biomass as an energy source

    Energy Technology Data Exchange (ETDEWEB)

    1980-10-01

    The results of a 20 month study to explore the technical and economic feasibility of fuelwood utilization to operate a 50 megawatt energy conversion facility are described. The availability of biomass as a fuel source, the methods of harvesting and collecting the fuelstock, the costs of providing adequate fuel to the plant, and other requirements for fueling the proposed conversion facility are investigated. (MHR)

  14. Are variations in heterotrophic soil respiration related to changes in substrate availability and microbial biomass carbon in the subtropical forests?

    Science.gov (United States)

    Wei, Hui; Chen, Xiaomei; Xiao, Guoliang; Guenet, Bertrand; Vicca, Sara; Shen, Weijun

    2015-12-16

    Soil temperature and moisture are widely-recognized controlling factors on heterotrophic soil respiration (Rh), although they often explain only a portion of Rh variability. How other soil physicochemical and microbial properties may contribute to Rh variability has been less studied. We conducted field measurements on Rh half-monthly and associated soil properties monthly for two years in four subtropical forests of southern China to assess influences of carbon availability and microbial properties on Rh. Rh in coniferous forest was significantly lower than that in the other three broadleaf species-dominated forests and exhibited obvious seasonal variations in the four forests (P forests. The quantity and decomposability of dissolved organic carbon (DOC) were significantly important to Rh variations, but the effect of DOC content on Rh was confounded with temperature, as revealed by partial mantel test. Microbial biomass carbon (MBC) was significantly related to Rh variations across forests during the warm season (P = 0.043). Our results suggest that DOC and MBC may be important when predicting Rh under some conditions, and highlight the complexity by mutual effects of them with environmental factors on Rh variations.

  15. The Influence of Tallow on Rumen Metabolism, Microbial Biomass Synthesis and Fatty Acid Composition of Bacteria and Protozoa

    DEFF Research Database (Denmark)

    Weisbjerg, Martin Riis; Børsting, Christian Friis; Hvelplund, Torben

    1992-01-01

    Rumen metabolism, microbial biomass synthesis and microbial long chain fatty acid composition were studied in lactating cows fed at two levels of dry matter intake (L, 8.6 kg DM and H, 12.6 kg DM) with 0, 4 and 6% added tallow at the low feed level (L0, L4 and L6) and 0, 2, 4 and 6% at the high...... feed level (H0, H2, H4 and H6). Fibre digestibility was not significantly affected by tallow addition. Increasing tallow level in the diet decreased the total VFA concentration, the ratio of acetic acid to propionic acid and the ammonia concentration in the rumen. Crude fat and fatty acid content...... in bacterial and protozoal dry matter increased with increased tallow level, especially due to an increase in fatty acids originating from the feeds. Microbial synthesis in the rumen and flow of amino acids to the duodenum was highest for medium fat intake at the high feed level....

  16. Are variations in heterotrophic soil respiration related to changes in substrate availability and microbial biomass carbon in the subtropical forests?

    Science.gov (United States)

    Wei, Hui; Chen, Xiaomei; Xiao, Guoliang; Guenet, Bertrand; Vicca, Sara; Shen, Weijun

    2015-01-01

    Soil temperature and moisture are widely-recognized controlling factors on heterotrophic soil respiration (Rh), although they often explain only a portion of Rh variability. How other soil physicochemical and microbial properties may contribute to Rh variability has been less studied. We conducted field measurements on Rh half-monthly and associated soil properties monthly for two years in four subtropical forests of southern China to assess influences of carbon availability and microbial properties on Rh. Rh in coniferous forest was significantly lower than that in the other three broadleaf species-dominated forests and exhibited obvious seasonal variations in the four forests (P < 0.05). Temperature was the primary factor influencing the seasonal variability of Rh while moisture was not in these humid subtropical forests. The quantity and decomposability of dissolved organic carbon (DOC) were significantly important to Rh variations, but the effect of DOC content on Rh was confounded with temperature, as revealed by partial mantel test. Microbial biomass carbon (MBC) was significantly related to Rh variations across forests during the warm season (P = 0.043). Our results suggest that DOC and MBC may be important when predicting Rh under some conditions, and highlight the complexity by mutual effects of them with environmental factors on Rh variations. PMID:26670822

  17. Global Partitioning of NOx Sources Using Satellite Observations: Relative Roles of Fossil Fuel Combustion, Biomass Burning and Soil Emissions

    Science.gov (United States)

    Jaegle, Lyatt; Steinberger, Linda; Martin, Randall V.; Chance, Kelly

    2005-01-01

    This document contains the following abstract for the paper "Global partitioning of NOx sources using satellite observations: Relative roles of fossil fuel combustion, biomass burning and soil emissions." Satellite observations have been used to provide important new information about emissions of nitrogen oxides. Nitrogen oxides (NOx) are significant in atmospheric chemistry, having a role in ozone air pollution, acid deposition and climate change. We know that human activities have led to a three- to six-fold increase in NOx emissions since pre-industrial times, and that there are three main surface sources of NOx: fuel combustion, large-scale fires, and microbial soil processes. How each of these sources contributes to the total NOx emissions is subject to some doubt, however. The problem is that current NOx emission inventories rely on bottom-up approaches, compiling large quantities of statistical information from diverse sources such as fuel and land use, agricultural data, and estimates of burned areas. This results in inherently large uncertainties. To overcome this, Lyatt Jaegle and colleagues from the University of Washington, USA, used new satellite observations from the Global Ozone Monitoring Experiment (GOME) instrument. As the spatial and seasonal distribution of each of the sources of NOx can be clearly mapped from space, the team could provide independent topdown constraints on the individual strengths of NOx sources, and thus help resolve discrepancies in existing inventories. Jaegle's analysis of the satellite observations, presented at the recent Faraday Discussion on "Atmospheric Chemistry", shows that fuel combustion dominates emissions at northern mid-latitudes, while fires are a significant source in the Tropics. Additionally, she discovered a larger than expected role for soil emissions, especially over agricultural regions with heavy fertilizer use. Additional information is included in the original extended abstract.

  18. Microbial lipid production by oleaginous yeast Cryptococcus sp. in the batch cultures using corncob hydrolysate as carbon source

    International Nuclear Information System (INIS)

    Chang, Yi-Huang; Chang, Ku-Shang; Lee, Ching-Fu; Hsu, Chuan-Liang; Huang, Cheng-Wei; Jang, Hung-Der

    2015-01-01

    To realize the feasibility of biodiesel production from high-lipid cell culture, microbial lipid production by the oleaginous yeasts was studied using glucose and sucrose as carbon source. Among the tested strains, Cryptococcus sp. SM5S05 accumulated the highest levels of intracellular lipids. The crude lipid contents of Cryptococcus sp. cultured in yeast malt agar reached 30% on a dry weight basis. The accumulation of lipids strongly depended on carbon/nitrogen ratio and nitrogen concentration. The highest content of lipids, measured at a carbon/nitrogen ratio of 60–90 and at a nitrogen concentration of 0.2%, was 60–57% lipids in the dry biomass. Batch cultures using corncob hydrolysate demonstrated that there was minimal inhibitory effect with a reducing sugar concentration of 60 g l −1 or higher. Batch cultures of Cryptococcus sp. SM5S05 in the corncob hydrolysate medium with 60 g l −1 glucose resulted in a dry biomass, lipid yields, and content of 12.6 g l −1 , 7.6 g l −1 , and 60.2%, respectively. The lipids contained mainly long-chain saturated and unsaturated fatty acids with 16 and 18 carbon atoms. The fatty acid profile of Cryptococcus oils was quite similar to that of conventional vegetable oil. The cost of lipid production could be further reduced with corncob hydrolysate being utilized as the raw material for the oleaginous yeast. The results showed that the microbial lipid from Cryptococcus sp. was a potential alternative resource for biodiesel production. - Highlights: • Microbial oil production from oleaginous yeast Cryptococcus sp. was studied. • Accumulation of lipid strongly depended on C/N ratio and nitrogen concentration. • Cultures in hydrolysate medium with 60 g/l glucose resulted in maximum lipid yields. • Maximal lipid content in the Cryptococcus sp. were 60.2% on dried weight basis

  19. Potential of hydrogen from oil palm biomass as a source of renewable energy worldwide

    International Nuclear Information System (INIS)

    Kelly-Yong, Tau Len; Lee, Keat Teong; Mohamed, Abdul Rahman; Bhatia, Subhash

    2007-01-01

    Various catastrophes related to extreme weather events such as floods, hurricanes, droughts and heat waves occurring on the Earth in the recent times are definitely a clear warning sign from nature questioning our ability to protect the environment and ultimately the Earth itself. Progressive release of greenhouse gases (GHG) such as CO 2 and CH 4 from development of various energy-intensive industries has ultimately caused human civilization to pay its debt. Realizing the urgency of reducing emissions and yet simultaneously catering to needs of industries, researches and scientists conclude that renewable energy is the perfect candidate to fulfill both parties requirement. Renewable energy provides an effective option for the provision of energy services from the technical point of view. In this context, biomass appears as one important renewable source of energy. Biomass has been a major source of energy in the world until before industrialization when fossil fuels become dominant and researches have proven from time to time its viability for large-scale production. Although there has been some successful industrial-scale production of renewable energy from biomass, generally this industry still faces a lot of challenges including the availability of economically viable technology, sophisticated and sustainable natural resources management, and proper market strategies under competitive energy markets. Amidst these challenges, the development and implementation of suitable policies by the local policy-makers is still the single and most important factor that can determine a successful utilization of renewable energy in a particular country. Ultimately, the race to the end line must begin with the proof of biomass ability to sustain in a long run as a sustainable and reliable source of renewable energy. Thus, the aim of this paper is to present the potential availability of oil palm biomass that can be converted to hydrogen (leading candidate positioned as the

  20. Effect of nitrogen sources on biomass, lipid and docosahexanoic acid production by Aurantiochytrium sp. SW1

    Science.gov (United States)

    Auma, Khairunnisa; Hamid, Aidil Abdul; Yusoff, Wan Mohtar Wan

    2018-04-01

    A local isolate, Aurantiochytrium sp. SW1 has been verified to have high content of docosahexanoic acid (DHA). However, the effect of different nitrogen sources on biomass, lipid concentration and DHA content in Aurantiochytrium sp. SW1 is still unknown. Hence, this study is focused in using six different organic and inorganic nitrogen sources to grow Aurantiochytrium sp. SW1 in optimized Burja medium. Monosodium glutamate (MSG) gave the highest biomass concentration of 15.97 g/L followed by ammonium nitrate (NH4NO3) with 13.37 g/L at 96 hr. These two nitrogen sources had significant effect on the biomass concentration (pDHA content in lipid showed cultivation using MSG reached 47.9% (4.95 g/L). Statistical analysis using least significant difference (LSD) showed significant lipid production (pDHA productivity (0.052 g/L hr-1) was obtained in medium containing MSG. This study proves that nitrogen component in the medium significantly affects the biomass concentration, lipid and DHA content.

  1. Opportunities for utilization of non-conventional energy sources for biomass pretreatment.

    Science.gov (United States)

    Singh, Rawel; Krishna, Bhavya B; Kumar, Jitendra; Bhaskar, Thallada

    2016-01-01

    The increasing concerns over the depletion of fossil resources and its associated geo-political issues have driven the entire world to move toward sustainable forms of energy. Pretreatment is the first step in any biochemical conversion process for the production of valuable fuels/chemicals from lignocellulosic biomass to eliminate the lignin and produce fermentable sugars by hydrolysis. Conventional techniques have several limitations which can be addressed by using them in tandem with non-conventional methods for biomass pretreatment. Electron beam and γ (gamma)-irradiation, microwave and ultrasound energies have certain advantages over conventional source of energy and there is an opportunity that these energies can be exploited for biomass pretreatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Contrasting effects of ammonium and nitrate additions on the biomass of soil microbial communities and enzyme activities in subtropical China

    Directory of Open Access Journals (Sweden)

    C. Zhang

    2017-10-01

    Full Text Available The nitrate to ammonium ratios in nitrogen (N compounds in wet atmospheric deposits have increased over the recent past, which is a cause for some concern as the individual effects of nitrate and ammonium deposition on the biomass of different soil microbial communities and enzyme activities are still poorly defined. We established a field experiment and applied ammonium (NH4Cl and nitrate (NaNO3 at monthly intervals over a period of 4 years. We collected soil samples from the ammonium and nitrate treatments and control plots in three different seasons, namely spring, summer, and fall, to evaluate the how the biomass of different soil microbial communities and enzyme activities responded to the ammonium (NH4Cl and nitrate (NaNO3 applications. Our results showed that the total contents of phospholipid fatty acids (PLFAs decreased by 24 and 11 % in the ammonium and nitrate treatments, respectively. The inhibitory effects of ammonium on Gram-positive bacteria (G+ and bacteria, fungi, actinomycetes, and arbuscular mycorrhizal fungi (AMF PLFA contents ranged from 14 to 40 % across the three seasons. We also observed that the absolute activities of C, N, and P hydrolyses and oxidases were inhibited by ammonium and nitrate, but that nitrate had stronger inhibitory effects on the activities of acid phosphatase (AP than ammonium. The activities of N-acquisition specific enzymes (enzyme activities normalized by total PLFA contents were about 21 and 43 % lower in the ammonium and nitrate treatments than in the control, respectively. However, the activities of P-acquisition specific enzymes were about 19 % higher in the ammonium treatment than in the control. Using redundancy analysis (RDA, we found that the measured C, N, and P hydrolysis and polyphenol oxidase (PPO activities were positively correlated with the soil pH and ammonium contents, but were negatively correlated with the nitrate contents. The PLFA biomarker contents were positively

  3. Contrasting effects of ammonium and nitrate additions on the biomass of soil microbial communities and enzyme activities in subtropical China

    Science.gov (United States)

    Zhang, Chuang; Zhang, Xin-Yu; Zou, Hong-Tao; Kou, Liang; Yang, Yang; Wen, Xue-Fa; Li, Sheng-Gong; Wang, Hui-Min; Sun, Xiao-Min

    2017-10-01

    The nitrate to ammonium ratios in nitrogen (N) compounds in wet atmospheric deposits have increased over the recent past, which is a cause for some concern as the individual effects of nitrate and ammonium deposition on the biomass of different soil microbial communities and enzyme activities are still poorly defined. We established a field experiment and applied ammonium (NH4Cl) and nitrate (NaNO3) at monthly intervals over a period of 4 years. We collected soil samples from the ammonium and nitrate treatments and control plots in three different seasons, namely spring, summer, and fall, to evaluate the how the biomass of different soil microbial communities and enzyme activities responded to the ammonium (NH4Cl) and nitrate (NaNO3) applications. Our results showed that the total contents of phospholipid fatty acids (PLFAs) decreased by 24 and 11 % in the ammonium and nitrate treatments, respectively. The inhibitory effects of ammonium on Gram-positive bacteria (G+) and bacteria, fungi, actinomycetes, and arbuscular mycorrhizal fungi (AMF) PLFA contents ranged from 14 to 40 % across the three seasons. We also observed that the absolute activities of C, N, and P hydrolyses and oxidases were inhibited by ammonium and nitrate, but that nitrate had stronger inhibitory effects on the activities of acid phosphatase (AP) than ammonium. The activities of N-acquisition specific enzymes (enzyme activities normalized by total PLFA contents) were about 21 and 43 % lower in the ammonium and nitrate treatments than in the control, respectively. However, the activities of P-acquisition specific enzymes were about 19 % higher in the ammonium treatment than in the control. Using redundancy analysis (RDA), we found that the measured C, N, and P hydrolysis and polyphenol oxidase (PPO) activities were positively correlated with the soil pH and ammonium contents, but were negatively correlated with the nitrate contents. The PLFA biomarker contents were positively correlated with soil

  4. Characterization of three plant biomass-degrading microbial consortia by metagenomics- and metasecretomics-based approaches

    DEFF Research Database (Denmark)

    Jiménez, Diego Javier; Brossi, Maria Julia de Lima; Schückel, Julia

    2016-01-01

    ). The highest degradation rates of lignin (~59 %) were observed with SG-M, whereas CS-M showed a high consumption of cellulose and hemicellulose. Analyses of the carbohydrate-active enzymes in the three microbial consortia showed the dominance of glycosyl hydrolases (e.g. of families GH3, GH43, GH13, GH10, GH29......), switchgrass (SG-M) and corn stover (CS-M) under aerobic and mesophilic conditions. Molecular fingerprintings, bacterial 16S ribosomal RNA (rRNA) gene amplicon sequencing and metagenomic analyses showed that the three microbial consortia were taxonomically distinct. Based on the taxonomic affiliation...

  5. Introduction to biomass energy project financing, funding sources and government strategies

    Energy Technology Data Exchange (ETDEWEB)

    Nordlinger, D E [Skadden, Arps, Slate, Meagher and Flom, London (United Kingdom); Shaw, F C [Skadden, Arps, Slate, Meagher and Flom, Washington, D.C. (United States)

    1995-12-01

    Biomass projects can help developing countries to protect their environment as well as to build a modem infrastructure. However, such projects present, in addition to the more typical risks associated with fossil-fuel projects, certain risks relating to the unique technologies and fuels used in such projects. Further, their location in developing countries regularly creates enhanced political and credit risk as well. Biomass power projects, like any other power project, must be financed. To be financeable, a power project should allocate risk in the most efficient way, so as to maximize return on investment. This paper examines the way in which various project documents can be structured to allocate most efficiently the technology and fuel risks unique to biomass projects, as well as the more typical risks, such as construction risk, permitting risk, expropriation risk, currency risk, country risk, sovereign risks, operating risks and credit risk. In addition, this paper summarizes the public financing sources and support that are available to assist in meeting the unique risk profiles of biomass projects. Specifically, it examines some of the principal multilateral and export credit agencies having involvement in this area. Finally, it examines potential strategies available to the developer of a biomass project for soliciting the involvement of, and negotiating with, local governments and public financing agencies. (author)

  6. Introduction to biomass energy project financing, funding sources and government strategies

    International Nuclear Information System (INIS)

    Nordlinger, D.E.; Shaw, F.C.

    1995-01-01

    Biomass projects can help developing countries to protect their environment as well as to build a modem infrastructure. However, such projects present, in addition to the more typical risks associated with fossil-fuel projects, certain risks relating to the unique technologies and fuels used in such projects. Further, their location in developing countries regularly creates enhanced political and credit risk as well. Biomass power projects, like any other power project, must be financed. To be financeable, a power project should allocate risk in the most efficient way, so as to maximize return on investment. This paper examines the way in which various project documents can be structured to allocate most efficiently the technology and fuel risks unique to biomass projects, as well as the more typical risks, such as construction risk, permitting risk, expropriation risk, currency risk, country risk, sovereign risks, operating risks and credit risk. In addition, this paper summarizes the public financing sources and support that are available to assist in meeting the unique risk profiles of biomass projects. Specifically, it examines some of the principal multilateral and export credit agencies having involvement in this area. Finally, it examines potential strategies available to the developer of a biomass project for soliciting the involvement of, and negotiating with, local governments and public financing agencies. (author)

  7. Onopordum nervosum as biomass source: some aspects of its production and transformation by enzymatic hydrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Manzanares, P; Negro, M J; Saez, R; Martin, C [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, Madrid (Spain). Inst. de Energias Renovables; Fernandez, J [ETSIA, Madrid (Spain). Dept. de Produccion Vegetal, Botanica y Proteccion Vegetal

    1993-01-01

    Onopordum nervosum, a lignocellulosic herbaceous species of the Iberian Peninsula, has been selected as a suitable biomass source to be used in transformation processes to obtain energy or industrial products. In this work, the effectiveness of different chemical pretreatments as a preliminary step to the enzymatic hydrolysis of this lignocellulosic biomass was evaluated. In order to determine biomass productivity, field assays were carried out in 1988 and 1989 using different planting densities and evaluating the effect to top fertilization. Biomass yields between 12 and 20 t ha[sup -1] were obtained, depending on the year and the planting density assayed. No significant differences were found in production rates when top fertilization was applied. Enzymatic hydrolysis of O.nervosum using a cellulolytic complex from Trichoderma longibrachiatum QM9414, gave low yields when untreated lignocellulosic biomass was used as substrate. Among different chemical pretreatments tested, ethanol and butanol solubilizations in the presence of a basic catalyst gave the best results. For the most effective pretreatment conditions, a delignification of about 30% and a complete recovery of glucose in the treated substrate were obtained both for butanol and ethanol. The highest enzymatic hydrolysis yields were found when ethanol was used as solvent, giving a saccharification efficiency of about 66% which, compared to the 23% for the native substrate, indicates the remarkable increment in the susceptibility of the cellulose to enzyme attack effected by this pretreatment. (author)

  8. Microbial correlates of Fusarium biomass and deoxynivalenol content in individual wheat seeds

    Science.gov (United States)

    Manipulating the microbiome of wheat seeds and heads may contribute to control of Fusarium head blight and mycotoxin accumulation in grain, which creates a food safety hazard. With the aim of identifying novel management targets, we looked for correlations between Fusarium biomass or deoxynivalenol ...

  9. Colloid-based multiplexed method for screening plant biomass-degrading glycoside hydrolase activities in microbial communities

    Energy Technology Data Exchange (ETDEWEB)

    Reindl, W.; Deng, K.; Gladden, J.M.; Cheng, G.; Wong, A.; Singer, S.W.; Singh, S.; Lee, J.-C.; Yao, J.-S.; Hazen, T.C.; Singh, A.K; Simmons, B.A.; Adams, P.D.; Northen, T.R.

    2011-05-01

    The enzymatic hydrolysis of long-chain polysaccharides is a crucial step in the conversion of biomass to lignocellulosic biofuels. The identification and characterization of optimal glycoside hydrolases is dependent on enzyme activity assays, however existing methods are limited in terms of compatibility with a broad range of reaction conditions, sample complexity, and especially multiplexity. The method we present is a multiplexed approach based on Nanostructure-Initiator Mass Spectrometry (NIMS) that allowed studying several glycolytic activities in parallel under diverse assay conditions. Although the substrate analogs carried a highly hydrophobic perfluorinated tag, assays could be performed in aqueous solutions due colloid formation of the substrate molecules. We first validated our method by analyzing known {beta}-glucosidase and {beta}-xylosidase activities in single and parallel assay setups, followed by the identification and characterization of yet unknown glycoside hydrolase activities in microbial communities.

  10. Influence of mechanical disintegration on the microbial growth of aerobic sludge biomass: A comparative study of ultrasonic and shear gap homogenizers by oxygen uptake measurements.

    Science.gov (United States)

    Divyalakshmi, P; Murugan, D; Sivarajan, M; Saravanan, P; Lajapathi Rai, C

    2015-11-01

    Wastewater treatment plant incorporates physical, chemical and biological processes to treat and remove the contaminants. The main drawback of conventional activated sludge process is the huge production of excess sludge, which is an unavoidable byproduct. The treatment and disposal of excess sludge costs about 60% of the total operating cost. The ideal way to reduce excess sludge production during wastewater treatment is by preventing biomass formation within the aerobic treatment train rather than post treatment of the generated sludge. In the present investigation two different mechanical devices namely, Ultrasonic and Shear Gap homogenizers have been employed to disintegrate the aerobic biomass. This study is intended to restrict the multiplication of microbial biomass and at the same time degrade the organics present in wastewater by increasing the oxidative capacity of microorganisms. The disintegrability on biomass was determined by biochemical methods. Degree of inactivation provides the information on inability of microorganisms to consume oxygen upon disruption. The soluble COD quantifies the extent of release of intra cellular compounds. The participation of disintegrated microorganism in wastewater treatment process was carried out in two identical respirometeric reactors. The results show that Ultrasonic homogenizer is very effective in the disruption of microorganisms leading to a maximum microbial growth reduction of 27%. On the other hand, Shear gap homogenizer does not favor the sludge growth reduction rather it facilitates the growth. This study also shows that for better microbial growth reduction, floc size reduction alone is not sufficient but also microbial disruption is essential. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Response of the soil microbial community and soil nutrient bioavailability to biomass harvesting and reserve tree retention in northern Minnesota aspen-dominated forests

    Science.gov (United States)

    Tera E. Lewandowski; Jodi A. Forrester; David J. Mladenoff; Anthony W. D' Amato; Brian J. Palik

    2016-01-01

    Intensive forest biomass harvesting, or the removal of harvesting slash (woody debris from tree branches and tops) for use as biofuel, has the potential to negatively affect the soil microbial community (SMC) due to loss of carbon and nutrient inputs from the slash, alteration of the soil microclimate, and increased nutrient leaching. These effects could result in...

  12. Microbial biomass and necromass turnover times in the contrasting seafloor settings

    DEFF Research Database (Denmark)

    Mhatre, Snehit

    2017-01-01

    in the deep biosphere microbial community. His work therefore opens a new avenue in exploring the possible mechanisms involved in facilitating the long-term survival of microorganisms under energy-deprived conditions. The PhD degree was completed at the Center for Geomicrobiology, department of Bioscience...

  13. RESPONSE OF SOIL MICROBIAL BIOMASS AND COMMUNITY COMPOSITION TO CHRONIC NITROGEN ADDITIONS AT HARVARD FOREST

    Science.gov (United States)

    Soil microbial communities may respond to anthropogenic increases in ecosystem nitrogen (N) availability, and their response may ultimately feedback on ecosystem carbon and N dynamics. We examined the long-term effects of chronic N additions on soil microbes by measuring soil mi...

  14. Effects of titanium dioxide nanoparticles on soil microbial communities and wheat biomass

    NARCIS (Netherlands)

    Moll, Janine; Klingenfuss, Florian; Widmer, Franco; Gogos, Alexander; Bucheli, Thomas D.; Hartmann, Martin; van der Heijden, Marcel G.A.

    2017-01-01

    Titanium dioxide nanoparticles (TiO2 NPs) are the most produced NPs worldwide and have great potential to be utilized in agriculture as additives for plant protection products. However, concerns have been raised that some NPs may negatively affect crops and soil microbial communities, including

  15. Abundance, production and stabilization of microbial biomass under conventional and reduced tillage

    NARCIS (Netherlands)

    Groenigen, van K.J.; Bloem, J.; Baath, E.; Boeckx, P.; Rousk, J.; Bodé, S.; Forristal, P.D.; Jones, M.B.

    2010-01-01

    Soil tillage practices affect the soil microbial community in various ways, with possible consequences for nitrogen (N) losses, plant growth and soil organic carbon (C) sequestration. As microbes affect soil organic matter (SOM) dynamics largely through their activity, their impact may not be

  16. Seasonal and interannual dynamics of soil microbial biomass and available nitrogen in an alpine meadow in the eastern part of Qinghai-Tibet Plateau, China

    Science.gov (United States)

    Xu, Bo; Wang, Jinniu; Wu, Ning; Wu, Yan; Shi, Fusun

    2018-01-01

    Soil microbial activity varies seasonally in frozen alpine soils during cold seasons and plays a crucial role in available N pool accumulation in soil. The intra- and interannual patterns of microbial and nutrient dynamics reflect the influences of changing weather factors, and thus provide important insights into the biogeochemical cycles and ecological functions of ecosystems. We documented the seasonal and interannual dynamics of soil microbial and available N in an alpine meadow in the eastern part of Qinghai-Tibet Plateau, China, between April 2011 and October 2013. Soil was collected in the middle of each month and analyzed for water content, microbial biomass C (MBC) and N (MBN), dissolved organic C and N, and inorganic N. Soil microbial community composition was measured by the dilution-plate method. Fungi and actinomycetes dominated the microbial community during the nongrowing seasons, and the proportion of bacteria increased considerably during the early growing seasons. Trends of consistently increasing MBC and available N pools were observed during the nongrowing seasons. MBC sharply declined during soil thaw and was accompanied by a peak in available N pool. Induced by changes in soil temperatures, significant shifts in the structures and functions of microbial communities were observed during the winter-spring transition and largely contributed to microbial reduction. The divergent seasonal dynamics of different N forms showed a complementary nutrient supply pattern during the growing season. Similarities between the interannual dynamics of microbial biomass and available N pools were observed, and soil temperature and water conditions were the primary environmental factors driving interannual fluctuations. Owing to the changes in climate, seasonal soil microbial activities and nutrient supply patterns are expected to change further, and these changes may have crucial implications for the productivity and biodiversity of alpine ecosystems.

  17. Selective enhancement and verification of woody biomass digestibility as a denitrification carbon source.

    Science.gov (United States)

    Hu, Rongting; Zheng, Xilai; Xin, Jia; Sun, Zhaoyue; Zheng, Tianyuan

    2017-11-01

    The denitrification efficiency of woody biomass as carbon source is low because of its poor carbon availability. In this study, representative poplar sawdust was pretreated with lime and peracetic acid to enhance the biomass digestibility to different degrees; sawdust was then mixed with soil to investigate its denitrification efficiency. Under controllable conditions (25-95°C, 12-24h, varying dosages), sawdust digestibility (characterized by reducing sugar yield) was selectively enhanced 1.0-21.8 times over that of the raw sawdust (28.8mgeq.glucoseg -1 dry biomass). This increase was mainly attributed to the removal of lignin from the biomass. As a carbon source, the sawdust (digestibility enhanced by 5.4 times) increased the nitrate removal rate by 4.7 times, without N 2 O emission. However, the sawdust with high digestibility (12.6 or 18.0 times), despite releasing more dissolved organic carbon (DOC), did not exhibit further increase in denitrification efficiency, and emitted N 2 O. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Dynamics of soil organic carbon and microbial biomass carbon in relation to water erosion and tillage erosion.

    Science.gov (United States)

    Xiaojun, Nie; Jianhui, Zhang; Zhengan, Su

    2013-01-01

    Dynamics of soil organic carbon (SOC) are associated with soil erosion, yet there is a shortage of research concerning the relationship between soil erosion, SOC, and especially microbial biomass carbon (MBC). In this paper, we selected two typical slope landscapes including gentle and steep slopes from the Sichuan Basin, China, and used the (137)Cs technique to determine the effects of water erosion and tillage erosion on the dynamics of SOC and MBC. Soil samples for the determination of (137)Cs, SOC, MBC and soil particle-size fractions were collected on two types of contrasting hillslopes. (137)Cs data revealed that soil loss occurred at upper slope positions of the two landscapes and soil accumulation at the lower slope positions. Soil erosion rates as well as distribution patterns of the erosion is the major process of soil redistribution in the gentle slope landscape, while tillage erosion acts as the dominant process of soil redistribution in the steep slope landscape. In gentle slope landscapes, both SOC and MBC contents increased downslope and these distribution patterns were closely linked to soil redistribution rates. In steep slope landscapes, only SOC contents increased downslope, dependent on soil redistribution. It is noticeable that MBC/SOC ratios were significantly lower in gentle slope landscapes than in steep slope landscapes, implying that water erosion has a negative effect on the microbial biomass compared with tillage erosion. It is suggested that MBC dynamics are closely associated with soil redistribution by water erosion but independent of that by tillage erosion, while SOC dynamics are influenced by soil redistribution by both water erosion and tillage erosion.

  19. The use of N 15 for studying the relation between the development of the microbial biomass and the remineralization of nitrogen fertilizer by rice

    Energy Technology Data Exchange (ETDEWEB)

    Al-Chater, M S [King Faisal University - Faculty of Agriculture and Food Science Department of Soil and Water Al-Hassa, (Saudi Arabia)

    1995-10-01

    The study aims at determining the mechanism of secondary mineralization of fertilizer N in the form of (N{sup 15} H{sub 14})2 SO{sub 4} which was transformed to the organic N using soil samples taken after a period of 16 weeks from the series of pot experiments. The development of the microbial biomass was studied using the method of Jenkinson and Powlson(1976) which was modified by Bottner et al (1984). Nitrogen mineralization was determined using the Stanford and Smith (1972) method. The study indicated that the values of mineralization constant varied from 0.0012 to 0.027 in different treatments. Accordingly, the half-life of microbial biomass ranged from 6 to 7 months, indicating fast transformation of microbial N as compared with total organic N in the soil which ranged between 7 to 12 years.1 fig., 3 tabs.

  20. To prevent the occurrence of black water agglomerate through delaying decomposition of cyanobacterial bloom biomass by sediment microbial fuel cell.

    Science.gov (United States)

    Zhou, Yan-Li; Jiang, He-Long; Cai, Hai-Yuan

    2015-04-28

    Settlement of cyanobacterial bloom biomass (CBB) into sediments in eutrophic lakes often induced the occurrence of black water agglomerate and then water quality deterioration. This study investigated the effect of sediment microbial fuel cell (SMFC) on CBB removal in sediments and related water pollution. Sediment bulking and subsequent black water from decomposition of settled CBB happened without SMFC, but were not observed over 100-day experiments with SMFC employment. While CBB in sediments improved power production from SMFC, the removal efficiency of organic matters in CBB-amended sediments with SMFC was significantly lower than that without SMFC. Pyrosequencing analysis showed higher abundances of the fermentative Clostridium and acetoclastic methanogen in CBB-amended bulk sediments without SMFC than with SMFC at the end of experiments. Obviously, SMFC operation changed the microbial community in CBB-amended sediments, and delayed the CBB degradation against sediment bulking. Thus, SMFC could be potentially applied as pollution prevention in CBB-settled and sensitive zones in shallow lakes. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. BioDry: An Inexpensive, Low-Power Method to Preserve Aquatic Microbial Biomass at Room Temperature.

    Science.gov (United States)

    Tuorto, Steven J; Brown, Chris M; Bidle, Kay D; McGuinness, Lora R; Kerkhof, Lee J

    2015-01-01

    This report describes BioDry (patent pending), a method for reliably preserving the biomolecules associated with aquatic microbial biomass samples, without the need of hazardous materials (e.g. liquid nitrogen, preservatives, etc.), freezing, or bulky storage/sampling equipment. Gel electrophoresis analysis of nucleic acid extracts from samples treated in the lab with the BioDry method indicated that molecular integrity was protected in samples stored at room temperature for up to 30 days. Analysis of 16S/18S rRNA genes for presence/absence and relative abundance of microorganisms using both 454-pyrosequencing and TRFLP profiling revealed statistically indistinguishable communities from control samples that were frozen in liquid nitrogen immediately after collection. Seawater and river water biomass samples collected with a portable BioDry "field unit", constructed from off-the-shelf materials and a battery-operated pumping system, also displayed high levels of community rRNA preservation, despite a slight decrease in nucleic acid recovery over the course of storage for 30 days. Functional mRNA and protein pools from the field samples were also effectively conserved with BioDry, as assessed by respective RT-PCR amplification and western blot of ribulose-1-5-bisphosphate carboxylase/oxygenase. Collectively, these results demonstrate that BioDry can adequately preserve a suite of biomolecules from aquatic biomass at ambient temperatures for up to a month, giving it great potential for high resolution sampling in remote locations or on autonomous platforms where space and power are limited.

  2. BioDry: An Inexpensive, Low-Power Method to Preserve Aquatic Microbial Biomass at Room Temperature.

    Directory of Open Access Journals (Sweden)

    Steven J Tuorto

    Full Text Available This report describes BioDry (patent pending, a method for reliably preserving the biomolecules associated with aquatic microbial biomass samples, without the need of hazardous materials (e.g. liquid nitrogen, preservatives, etc., freezing, or bulky storage/sampling equipment. Gel electrophoresis analysis of nucleic acid extracts from samples treated in the lab with the BioDry method indicated that molecular integrity was protected in samples stored at room temperature for up to 30 days. Analysis of 16S/18S rRNA genes for presence/absence and relative abundance of microorganisms using both 454-pyrosequencing and TRFLP profiling revealed statistically indistinguishable communities from control samples that were frozen in liquid nitrogen immediately after collection. Seawater and river water biomass samples collected with a portable BioDry "field unit", constructed from off-the-shelf materials and a battery-operated pumping system, also displayed high levels of community rRNA preservation, despite a slight decrease in nucleic acid recovery over the course of storage for 30 days. Functional mRNA and protein pools from the field samples were also effectively conserved with BioDry, as assessed by respective RT-PCR amplification and western blot of ribulose-1-5-bisphosphate carboxylase/oxygenase. Collectively, these results demonstrate that BioDry can adequately preserve a suite of biomolecules from aquatic biomass at ambient temperatures for up to a month, giving it great potential for high resolution sampling in remote locations or on autonomous platforms where space and power are limited.

  3. Factors for Microbial Carbon Sources in Organic and Mineral Soils from Eastern United States Deciduous Forests

    Energy Technology Data Exchange (ETDEWEB)

    Stitt, Caroline R. [Mills College, Oakland, CA (United States)

    2013-09-16

    Forest soils represent a large portion of global terrestrial carbon; however, which soil carbon sources are used by soil microbes and respired as carbon dioxide (CO2) is not well known. This study will focus on characterizing microbial carbon sources from organic and mineral soils from four eastern United States deciduous forests using a unique radiocarbon (14C) tracer. Results from the dark incubation of organic and mineral soils are heavily influenced by site characteristics when incubated at optimal microbial activity temperature. Sites with considerable differences in temperature, texture, and location differ in carbon source attribution, indicating that site characteristics play a role in soil respiration.

  4. [Influence of different slope position and profile in Disporopsis pernyi forest land on soil microbial biomass and enzyme activity in southwest Karst mountain of China ].

    Science.gov (United States)

    Qin, Hua-Jun; He, Bing-Hui; Zhao, Xuan-chi; Li, Yuan; Mao, Wen-tao; Zeng, Qing-ping

    2014-09-01

    Soil microbial biomass and enzyme activity are important parameters to evaluate the quality of the soil environment. The goal of this study was to determine the influence of different slope position and section in Disporopsis pernyi forest land on the soil microbial biomass and enzyme activity in southwest Karst Mountain. In this study, we chose the Dip forest land at Yunfo village Chengdong town Liangping country Chongqing Province as the study object, to analyze the influence of three different slope positions [Up Slope(US), Middle Slope(MS), Below Slope(BS)] and two different sections-upper layer(0-15 cm) and bottom layer(15-30 cm) on the soil microbial biomass carbon (SMBC), soil microbial biomass nitrogen (SMBN), microbial carbon entropy (qMBC), microbial nitrogen entropy (qMBN) , catalase(CAT), alkaline phosphatase (ALK), urease(URE), and invertase(INV). The results showed that the same trend (BS > MS > US) was found for SMBC, SMBN, qMBC, qMBN, CAT and INV of upper soil layer, while a different trend (BS > US > MS) was observed for ALK. In addition, another trend (MS > US > BS) was observed for URE. The same trend (BS > MS >US) was observed for SMBN, qMBN, CAT, ALK, URE and INV in bottom layer, but a different trend (MS > BS > US) was observed for SMBC and qMBC. The SMBC, SMBN, CAT, ALK, URE and INV manifested as upper > bottom with reduction of the section, while qMBC and qMBN showed the opposite trend. Correlation analysis indicated that there were significant (P <0.05) or highly significant (P < 0.01) positive correlations among SMBC in different slope position and section, soil enzyme activity and moisture. According to the two equations of regression analysis, SMBC tended to increase with the increasing CAT and ALK, while decreased with the increasing pH. Then SMBN tended to increase with the increasing URE and INV.

  5. Assimilable organic carbon (AOC) in soil water extracts using Vibrio harveyi BB721 and its implication for microbial biomass.

    Science.gov (United States)

    Ma, Jincai; Ibekwe, A Mark; Wang, Haizhen; Xu, Jianming; Leddy, Menu; Yang, Ching-Hong; Crowley, David E

    2012-01-01

    Assimilable organic carbon (AOC) is commonly used to measure the growth potential of microorganisms in water, but has not yet been investigated for measuring microbial growth potential in soils. In this study, a simple, rapid, and non-growth based assay to determine AOC in soil was developed using a naturally occurring luminous strain Vibrio harveyi BB721 to determine the fraction of low molecular weight organic carbon in soil water extract. Calibration of the assay was achieved by measuring the luminescence intensity of starved V. harveyi BB721 cells in the late exponential phase with a concentration range from 0 to 800 µg l(-1) glucose (equivalent to 0-16.0 mg glucose C kg(-1) soil) with the detection limit of 10 µg l(-1) equivalent to 0.20 mg glucose C kg(-1) soil. Results showed that bioluminescence was proportional to the concentration of glucose added to soil. The luminescence intensity of the cells was highly pH dependent and the optimal pH was about 7.0. The average AOC concentration in 32 soils tested was 2.9±2.2 mg glucose C kg(-1). Our data showed that AOC levels in soil water extracts were significantly correlated (Pgrowth bioluminescence based assay. Understanding the levels of AOC in soil water extract provides new insights into our ability to estimate the most available carbon pool to bacteria in soil that may be easily assimilated into cells for many metabolic processes and suggest possible the links between AOC, microbial regrowth potential, and microbial biomass in soils.

  6. Microbial Production of Short Chain Fatty Acids from Lignocellulosic Biomass: Current Processes and Market

    Directory of Open Access Journals (Sweden)

    Ivan Baumann

    2016-01-01

    Full Text Available Biological production of organic acids from conversion of biomass derivatives has received increased attention among scientists and engineers and in business because of the attractive properties such as renewability, sustainability, degradability, and versatility. The aim of the present review is to summarize recent research and development of short chain fatty acids production by anaerobic fermentation of nonfood biomass and to evaluate the status and outlook for a sustainable industrial production of such biochemicals. Volatile fatty acids (VFAs such as acetic acid, propionic acid, and butyric acid have many industrial applications and are currently of global economic interest. The focus is mainly on the utilization of pretreated lignocellulosic plant biomass as substrate (the carbohydrate route and development of the bacteria and processes that lead to a high and economically feasible production of VFA. The current and developing market for VFA is analyzed focusing on production, prices, and forecasts along with a presentation of the biotechnology companies operating in the market for sustainable biochemicals. Finally, perspectives on taking sustainable product of biochemicals from promise to market introduction are reviewed.

  7. Root systems and soil microbial biomass under no-tillage system

    Directory of Open Access Journals (Sweden)

    Venzke Filho Solismar de Paiva

    2004-01-01

    Full Text Available Some root parameters such as distribution, length, diameter and dry matter are inherent to plant species. Roots can influence microbial population during vegetative cycle through the rhizodeposits and, after senescence, integrating the soil organic matter pool. Since they represent labile substrates, especially regarding nitrogen, they can determine the rate of nutrient availability to the next crop cultivated under no-tillage (NT. The root systems of two crop species: maize (Zea mays L. cultivar Cargill 909 and soybean [Glycine max (L. Merr.] cultivar Embrapa 59, were compared in the field, and their influence on spatial distribution of the microbial C and N in a clayey-textured Typic Hapludox cultivated for 22 years under NT, at Tibagi, State of Paraná (PR, Brazil, was determined. Digital image processing and nail-plate techniques were used to evaluate 40 plots of a 80 ´ 50 ´ 3 cm soil profile. It was observed that 36% and 30% of the maize and soybeans roots, respectively, are concentrated in the 0 to 10 cm soil layer. The percent distribution of root dry matter was similar for both crops. The maize roots presented a total of 1,324 kg C ha-1 and 58 kg N ha-1, with higher root dry matter density and more roots in decomposition in the upper soil layer, decreasing with depth. The soybean roots (392 kg C ha-1 and 21 kg N ha-1 showed higher number of thinner roots and higher density per length unity compared to the maize. The maize roots enhanced microbial-C down to deeper soil layers than did the soybean roots. The microbial N presented a better correlation with the concentration of thin active roots and with roots in decomposition or in indefinite shape, possibly because of higher concentration of C and N easily assimilated by soil microorganisms.

  8. Assessment of the microbial quality of river water sources in rural ...

    African Journals Online (AJOL)

    drinie

    2002-07-03

    Jul 3, 2002 ... Assessment of the microbial quality of river water sources ... These untreated water sources are used for drinking and domestic purposes and pose a serious threat to ... These diseases cause crippling, devastating and debilitating effects ..... gastrointestinal illness, due mainly by enteric viruses in sewage.

  9. Application of microbial biomass and activity measures to assess in situ bioremediation of chlorinated solvents

    International Nuclear Information System (INIS)

    Phelps, T.J.; Herbes, S.E.; Palumbo, A.V.; Pfiffner, S.M.; Mackowski, R.; Ringelberg, D.; White, D.C.; Tennessee Univ., Knoxville, TN

    1993-01-01

    Evaluating the effectiveness of chlorinated solvent remediation in the subsurface can be a significant problem given uncertainties in estimating the total mass of contaminants present. If the remediation technique is a biological activity, information on the progress and success of the remediation may be gained by monitoring changes in the mass and activities of microbial populations. The in situ bioremediation demonstration at the US Department of Energy (DOE) Savannah River Site (SRS) is designed to test the effectiveness of methane injection for the stimulation of in sediments. Past studies have shown the potential for degradation by native microbial populations. The design and implementation of the SRS Integrated Demonstration is described in this volume. A control phase without treatment was followed by a phase withdrawing air. The next phase included vacuum extraction plus air injection into the lower horizontal well located below the water table. The next period included the injection of 1% methane in air followed by injection of 4% methane in air. Based on the literature, it was hypothesized that the injection of methane would stimulate methanotrophic populations and thus accelerate biological degradation of TCE. Measuring the success of bioremediation is a complex effort that includes monitoring of changes in microbial populations associated with TCE degradation. These monitoring efforts are described in this paper and in related papers in this volume

  10. Soil microbial activities and its relationship with soil chemical ...

    African Journals Online (AJOL)

    The fields assessed are organically managed Soils (OMS), Inorganically Managed Soils (IMS) and an Uncultivated Land having grass coverage (ULS). Soil Microbial Respiration (SMR), Microbial Biomass Carbon (MBC), Microbial Biomass Nitrogen (MBN) and Microbial Biomass Phosphorus (MBP) were analyzed.

  11. Evaluating the composition and processing potential of novel sources of Brazilian biomass for sustainable biorenewables production.

    Science.gov (United States)

    Lima, Marisa A; Gomez, Leonardo D; Steele-King, Clare G; Simister, Rachael; Bernardinelli, Oigres D; Carvalho, Marcelo A; Rezende, Camila A; Labate, Carlos A; Deazevedo, Eduardo R; McQueen-Mason, Simon J; Polikarpov, Igor

    2014-01-18

    The search for promising and renewable sources of carbohydrates for the production of biofuels and other biorenewables has been stimulated by an increase in global energy demand in the face of growing concern over greenhouse gas emissions and fuel security. In particular, interest has focused on non-food lignocellulosic biomass as a potential source of abundant and sustainable feedstock for biorefineries. Here we investigate the potential of three Brazilian grasses (Panicum maximum, Pennisetum purpureum and Brachiaria brizantha), as well as bark residues from the harvesting of two commercial Eucalyptus clones (E. grandis and E. grandis x urophylla) for biofuel production, and compare these to sugarcane bagasse. The effects of hot water, acid, alkaline and sulfite pretreatments (at increasing temperatures) on the chemical composition, morphology and saccharification yields of these different biomass types were evaluated. The average yield (per hectare), availability and general composition of all five biomasses were compared. Compositional analyses indicate a high level of hemicellulose and lignin removal in all grass varieties (including sugarcane bagasse) after acid and alkaline pretreatment with increasing temperatures, whilst the biomasses pretreated with hot water or sulfite showed little variation from the control. For all biomasses, higher cellulose enrichment resulted from treatment with sodium hydroxide at 130°C. At 180°C, a decrease in cellulose content was observed, which is associated with high amorphous cellulose removal and 5-hydroxymethyl-furaldehyde production. Morphological analysis showed the effects of different pretreatments on the biomass surface, revealing a high production of microfibrillated cellulose on grass surfaces, after treatment with 1% sodium hydroxide at 130°C for 30 minutes. This may explain the higher hydrolysis yields resulting from these pretreatments, since these cellulosic nanoparticles can be easily accessed and cleaved by

  12. Characterization and comparison of biomass produced from various sources: Suggestions for selection of pretreatment technologies in biomass-to-energy

    International Nuclear Information System (INIS)

    Chiang, Kung-Yuh; Chien, Kuang-Li; Lu, Cheng-Han

    2012-01-01

    Highlights: ► Biomass with higher volatile matter content has a higher carbon conversion rate. ► Applying the suitable pretreatment techniques that will enhance the bioenergy yield. ► The ratio of H 2 O/fixed carbon is a critical factor for enhancing the energy conversion. -- Abstract: This study investigated the characteristics of 26 varieties of biomass produced from forestry, agriculture, municipality, and industry in Taiwan to test their applicability in thermal conversion technologies and evaluation of enhanced energy efficiency. Understanding the reactivity of the tested biomass, the cluster analysis was also used in this research to classify into characteristics groups of biomass. This research also evaluated the feasibility of energy application of tested biomass by comparing it to the physicochemical properties of various coals used in Taiwan’s power plants. The experimental results indicated that the volatile matter content of the all tested biomass was 60% and above. It can be concluded that the higher carbon conversion rate will occur in the thermal conversion process of all tested biomass. Based on the results of lower heating value (LHV) of MSW and non-hazardous industrial sludge, the LHV was lower than other tested biomass that was between 1000 and 1800 kcal/kg. This is due to the higher moisture content of MSW and sludge that resulted in the lower LHV. Besides, the LHV of other tested biomass and their derived fuels was similar to the tested coal. However, the energy densities of woody and agricultural waste were smaller than that of the coal because the bulky densities of woody and agricultural wastes were low. That is, the energy utilization efficiency of woody and agricultural waste was relatively low. To improve the energy density of tested biomass, appropriate pre-treatment technologies, such as shredding, pelletizing or torrefied technologies can be applied, that will enhance the energy utilization efficiency of all tested biomass.

  13. Photosynthetic Microbial Mats are Exemplary Sources of Diverse Biosignatures (Invited)

    Science.gov (United States)

    Des Marais, D. J.; Jahnke, L. L.

    2013-12-01

    Marine cyanobacterial microbial mats are widespread, compact, self-contained ecosystems that create diverse biosignatures and have an ancient fossil record. Within the mats, oxygenic photosynthesis provides organic substrates and O2 to the community. Both the absorption and scattering of light change the intensity and spectral composition of incident radiation as it penetrates a mat. Some phototrophs utilize infrared light near the base of the photic zone. A mat's upper layers can become highly reduced and sulfidic at night. Counteracting gradients of O2 and sulfide shape the chemical environment and provide daily-contrasting microenvironments separated on a scale of a few mm. Radiation hazards (UV, etc.), O2 and sulfide toxicity elicit motility and other physiological responses. This combination of benefits and hazards of light, O2 and sulfide promotes the allocation of various essential mat processes between light and dark periods and to various depths in the mat. Associated nonphotosynthetic communities, including anaerobes, strongly influence many of the ecosystem's overall characteristics, and their processes affect any biosignatures that enter the fossil record. A biosignature is an object, substance and/or pattern whose origin specifically requires a biological agent. The value of a biosignature depends not only on the probability of life creating it, but also on the improbability of nonbiological processes producing it. Microbial mats create biosignatures that identify particular groups of organisms and also reveal attributes of the mat ecosystem. For example, branched hydrocarbons and pigments can be diagnostic of cyanobacteria and other phototrophic bacteria, and isoprenoids can indicate particular groups of archea. Assemblages of lipid biosignatures change with depth due to changes in microbial populations and diagenetic transformations of organic matter. The 13C/12C values of organic matter and carbonates reflect isotopic discrimination by particular

  14. Sorption studies of radioiodine on soils with special references to soil microbial biomass

    Energy Technology Data Exchange (ETDEWEB)

    Bors, J. (Niedersaechsisches Inst. fuer Radiooekologie, Hannover (Germany, F.R.)); Erten, H. (Bilkent Univ., Ankara (Turkey). Dept. of Chemistry); Martens, R. (Bundesforschungsanstalt fuer Landwirtschaft, Braunschweig (Germany, F.R.). Inst. fuer Bodenbiologie)

    1991-01-01

    In batch experiments with two types of soils, chernozem and podzol, radioiodine ({sup 125}I) showed an initial rapid sorption, followed by a long and slow further increase. Very little sorption (R{sub d} < 1) was detected in clay minerals. Generally, higher R{sub d}-values were observed for the chernozem soil, characterized by a higher amount of organic substance and of soil biomass. The sorption process was predominantly irreversible, the isotherms were linear at low ion concentrations and deviated from linearity starting at 10{sup -5} mmol.ml{sup -1}. Sorption ratio was found to increase with increasing volume to mass ratio. The composition of liquid phases (bidistilled water, synthetic soil water, rain water) highly affected iodine sorption. In experiments with KBr solution, the sorption of I{sup -} was found to be strongly preferred to Br{sup -}. Incubation of soil samples under varied conditions (decreased or increased soil biomass, O{sub 2}-concentration, incubation temperature, soil water content and storage conditions) delivered indications for the participation of soil microflora in iodine immobilization. Test with isolated soil bacteria and fungi showed that radioiodine can be incorporated by soil microorganisms under certain conditions only: Considerable uptake of radioiodine was found in washed (NaCl, CaCl{sub 2}) cells with both bacteria and fungi, but no incorporation was detected into cells incubated with radioiodine in the culture medium. (orig.).

  15. Sorption studies of radioiodine on soils with special references to soil microbial biomass

    International Nuclear Information System (INIS)

    Bors, J.; Erten, H.; Martens, R.

    1991-01-01

    In batch experiments with two types of soils, chernozem and podzol, radioiodine ( 125 I) showed an initial rapid sorption, followed by a long and slow further increase. Very little sorption (R d d -values were observed for the chernozem soil, characterized by a higher amount of organic substance and of soil biomass. The sorption process was predominantly irreversible, the isotherms were linear at low ion concentrations and deviated from linearity starting at 10 -5 mmol.ml -1 . Sorption ratio was found to increase with increasing volume to mass ratio. The composition of liquid phases (bidistilled water, synthetic soil water, rain water) highly affected iodine sorption. In experiments with KBr solution, the sorption of I - was found to be strongly preferred to Br - . Incubation of soil samples under varied conditions (decreased or increased soil biomass, O 2 -concentration, incubation temperature, soil water content and storage conditions) delivered indications for the participation of soil microflora in iodine immobilization. Test with isolated soil bacteria and fungi showed that radioiodine can be incorporated by soil microorganisms under certain conditions only: Considerable uptake of radioiodine was found in washed (NaCl, CaCl 2 ) cells with both bacteria and fungi, but no incorporation was detected into cells incubated with radioiodine in the culture medium. (orig.)

  16. Seasonal Variation in Soil Microbial Biomass, Bacterial Community Composition and Extracellular Enzyme Activity in Relation to Soil Respiration in a Northern Great Plains Grassland

    Science.gov (United States)

    Wilton, E.; Flanagan, L. B.

    2014-12-01

    Soil respiration rate is affected by seasonal changes in temperature and moisture, but is this a direct effect on soil metabolism or an indirect effect caused by changes in microbial biomass, bacterial community composition and substrate availability? In order to address this question, we compared continuous measurements of soil and plant CO2 exchange made with an automatic chamber system to analyses conducted on replicate soil samples collected on four dates during June-August. Microbial biomass was estimated from substrate-induced respiration rate, bacterial community composition was determined by 16S rRNA amplicon pyrosequencing, and β-1,4-N-acetylglucosaminidase (NAGase) and phenol oxidase enzyme activities were assayed fluorometrically or by absorbance measurements, respectively. Soil microbial biomass declined from June to August in strong correlation with a progressive decline in soil moisture during this time period. Soil bacterial species richness and alpha diversity showed no significant seasonal change. However, bacterial community composition showed a progressive shift over time as measured by Bray-Curtis dissimilarity. In particular, the change in community composition was associated with increasing relative abundance in the alpha and delta classes, and declining abundance of the beta and gamma classes of the Proteobacteria phylum during June-August. NAGase showed a progressive seasonal decline in potential activity that was correlated with microbial biomass and seasonal changes in soil moisture. In contrast, phenol oxidase showed highest potential activity in mid-July near the time of peak soil respiration and ecosystem photosynthesis, which may represent a time of high input of carbon exudates into the soil from plant roots. This input of exudates may stimulate the activity of phenol oxidase, a lignolytic enzyme involved in the breakdown of soil organic matter. These analyses indicated that seasonal change in soil respiration is a complex

  17. The removal of uranium from mining waste water using algal/microbial biomass

    International Nuclear Information System (INIS)

    Kalin, Margarete; Wheeler, W.N.; Meinrath, G.

    2004-01-01

    We describe a three step process for the removal of uranium (U) from dilute waste waters. Step one involves the sequestration of U on, in, and around aquatic plants such as algae. Cell wall ligands efficiently remove U(VI) from waste water. Growing algae continuously renew the cellular surface area. Step 2 is the removal of U-algal particulates from the water column to the sediments. Step 3 involves reducing U(VI) to U(IV) and transforming the ions into stable precipitates in the sediments. The algal cells provide organic carbon and other nutrients to heterotrophic microbial consortia to maintain the low E H , within which the U is transformed. Among the microorganisms, algae are of predominant interest for the ecological engineer because of their ability to sequester U and because some algae can live under many extreme environments, often in abundance. Algae grow in a wide spectrum of water qualities, from alkaline environments (Chara, Nitella) to acidic mine drainage waste waters (Mougeotia, Ulothrix). If they could be induced to grow in waste waters, they would provide a simple, long-term means to remove U and other radionuclides from U mining effluents. This paper reviews the literature on algal and microbial adsorption, reduction, and transformation of U in waste streams, wetlands, lakes and oceans

  18. Algal biomass as a global source of transport fuels: Overview and development perspectives

    Directory of Open Access Journals (Sweden)

    Kifayat Ullah

    2014-08-01

    Full Text Available As a result of the global fuel crisis of the early 1970s, coupled with concerns for the environment, the use of biofuel has been on the increase in many regions throughout the world. At present, a total of approximately 30 billion (30×109 liters of biofuel are utilized worldwide annually, although most countries rely hugely on the first generation biofuel. The limitations of the first and second generation biofuel gave rise to current interest in algae as a promising alternative to these conventional biofuel sources. Algal biomass could provide a lion׳s share of the global transport fuel requirements in future. The present review highlights some important developments in, and potentials of algaculture as a major biomass resource of the future. However, the major constraint to commercial-scale algae farming for energy production is the cost factor, which must be addressed adequately before its potentials can be harnessed.

  19. Multiple approaches to microbial source tracking in tropical northern Australia

    KAUST Repository

    Neave, Matthew; Luter, Heidi; Padovan, Anna; Townsend, Simon; Schobben, Xavier; Gibb, Karen

    2014-01-01

    , other potential inputs, such as urban rivers and drains, and surrounding beaches, and used genetic fingerprints from E. coli and enterococci communities, fecal markers and 454 pyrosequencing to track contamination sources. A sewage effluent outfall

  20. Microbial community distribution and activity dynamics of granular biomass in a CANON reactor

    DEFF Research Database (Denmark)

    Vázquez-Padín, Jose; Mosquera-Corral, Anuska; Campos, Jose Luis

    2010-01-01

     (Lgranule)-1 d-1. Anammox activity was registered between 400 and 1000 μm depth inside the granules. The nitrogen removal capacity of the studied sequencing batch reactor containing the granular biomass was of 0.5 g N L-1 d-1. This value is similar to the mean nitrogen removal rate obtained from...... calculations based on in- and outflow concentrations. Information obtained in the present work allowed the establishment of a simple control strategy based on the measurements of NH4+ and NO2- in the bulk liquid and acting over the dissolved oxygen concentration in the bulk liquid and the hydraulic retention...

  1. Source apportionment of air pollution exposures of rural Chinese women cooking with biomass fuels

    Science.gov (United States)

    Huang, Wei; Baumgartner, Jill; Zhang, Yuanxun; Wang, Yuqin; Schauer, James J.

    2015-03-01

    Particulate matter (PM) from different sources may differentially affect human health. Few studies have assessed the main sources of personal exposure to PM and their contributions among residents of developing countries, where pollution sources differ from those in higher-income settings. 116 daily (24-h) personal PM2.5 exposure samples were collected among 81 women cooking with biomass fuels in two villages in rural Yunnan, China. The PM samples were analyzed for mass and chemical composition, including water-soluble organic carbon (WSOC), black carbon (BC), and molecular markers. We found black carbon, n-alkanes and levoglucosan dominated the most abundant fractions of the total measured species and average personal PM2.5 exposure was higher in winter than that in summer in both villages. The composition data were then analyzed using a positive matrix factorization (PMF) receptor model to identify the main PM emission sources contributing to women's exposures and to assess their spatial (between villages) and seasonal variation in our study setting. The 6-factor solution provided reasonably stable profiles and was selected for further analysis. Our results show that rural Chinese women cooking with biomass fuels are exposed to a variety of sources. The identified factors include wood combustion (41.1%), a cooking source (35.6%), a mobile source (12.6%), plant waxes (6.7%), pyrolysis combustion (3.0%), and secondary organic aerosols (SOA; 1.0%). The mean source contributions of the mobile source, cooking source, and wood combustion factor to PM2.5 exposure were significantly different between women living in the two study villages, whereas the mean SOA, wood combustion, and plant waxes factors differed seasonally. There was no relationship between source contributions and questionnaire-based measurements of source-specific exposures, implying that the impacts of source contributions on exposure are affected by complex spatial, temporal and behavioral patterns

  2. [Effects of different application rates of calcium cyanamide on soil microbial biomass and enzyme activity in cucumber continuous cropping].

    Science.gov (United States)

    Zhang, Xue-peng; Ning, Tang-yuan; Yang, Yan; Sun, Tao; Zhang, Shu-min; Wang, Bin

    2015-10-01

    A 2-year field experiment was conducted to study the effects of CaCN2 combined with cucumber straw retention on soil microbial biomass carbon (SMBC) , soil microbial biomass nitrogen (SMBN) and soil enzyme activities under cucumber continuous cropping system. Four treatments were used in this study as follows: CK (null CaCN2), CaCN2-90 (1350 kg CaCN2 . hm-2) CaCN2-60 (900 kg CaCN2 . hm-2), CaCN2-30 (450 kg CaCN2 . hm-2). The results indicated that, compared with the other treatments, CaCN2-90 treatment significantly decreased SMBC in 0-10 cm soil layer at seedling stage, but increased SMBC in 0-20 cm soil layer after early-fruit stage. Compared with CK, CaCN2 increased SMBC in 0-20 cm soil layer at late-fruit stage, and increased SMBN in 0-10 cm soil layer at mid- and late-fruit stages, however there was no significant trend among CaCN2 treatments in the first year (2012), while in the second year (2013) SMBN increased with the increasing CaCN2 amount after mid-fruit stage. CaCN2 increased straw decaying and nutrients releasing, and also increased soil organic matter. Furthermore, the CaCN2-90 could accelerate straw decomposition. Compared with CK, CaCN2 effectively increased soil urease, catalase and polyphenol oxidase activity. The soil urease activity increased while the polyphenol oxidase activity decreased with the increase of CaCN2, and CaCN2-60 could significantly improve catalase activity. Soil organic matter, urease activity and catalase activity had significant positive correlations with SMBC and SMBN. However, polyphenol oxidase activity was negatively correlated to SMBC and SMBN. Our findings indicated that CaCN2 application at 900 kg . hm-2 combined with cucumber straw retention could effectively improve soil environment, alleviating the soil obstacles under the cucumber continuous cropping system.

  3. Digestate as nutrient source for biomass production of sida, lucerne and maize

    Science.gov (United States)

    Bueno Piaz Barbosa, Daniela; Nabel, Moritz; Horsch, David; Tsay, Gabriela; Jablonowski, Nicolai

    2014-05-01

    Biogas as a renewable energy source is supported in many countries driven by climate and energy policies. Nowadays, Germany is the largest biogas producer in the European Union. A sustainable resource management has to be considered within this growing scenario of biogas production systems and its environmental impacts. In this respect, studies aiming to enhance the management of biogas residues, which represents a valuable source of nutrients and organic fertilization, are needed. Our objective was to evaluate the digestate (biogas residue after fermentation process) application as nutrient source for biomass production of three different plants: sida (Sida hermaphrodita - Malvaceae), lucerne (Medicago sativa - Fabaceae) and maize (Zea mays - Poaceae). The digestate was collected from an operating biogas facility (fermenter volume 2500m³, ADRW Natur Power GmbH & Co.KG Titz/Ameln, Germany) composed of maize silage as the major feedstock, and minor amounts of chicken manure, with a composition of 3,29% N; 1,07% P; 3,42% K; and 41,2% C. An arable field soil (Endogleyic Stagnosol) was collected from 0-30 cm depth and 5 mm sieved. The fertilizer treatments of the plants were established in five replicates including digestate (application amount equivalent to 40 t ha-1) and NPK fertilizer (application amount equivalent to 200:100:300 kg ha-1) applications, according to the recommended agricultural doses, and a control (no fertilizer application). The digestate and the NPK fertilizer were thoroughly mixed with the soil in a rotatory shaker for 30 min. The 1L pots were filled with the fertilized soil and the seedlings were transplanted and grown for 30 days under greenhouse conditions (16 h day/8 h night: 24ºC/18ºC; 60% air humidity). After harvesting, the leaf area was immediately measured, and the roots were washed to allow above and below-ground biomass determination. Subsequently, shoots and roots were dried at 60ºC for 48 hours. The biomass and leaf area of sida

  4. Microbial habitability of Europa sustained by radioactive sources.

    Science.gov (United States)

    Altair, Thiago; de Avellar, Marcio G B; Rodrigues, Fabio; Galante, Douglas

    2018-01-10

    There is an increasing interest in the icy moons of the Solar System due to their potential habitability and as targets for future exploratory missions, which include astrobiological goals. Several studies have reported new results describing the details of these moons' geological settings; however, there is still a lack of information regarding the deep subsurface environment of the moons. The purpose of this article is to evaluate the microbial habitability of Europa constrained by terrestrial analogue environments and sustained by radioactive energy provided by natural unstable isotopes. The geological scenarios are based on known deep environments on Earth, and the bacterial ecosystem is based on a sulfate-reducing bacterial ecosystem found 2.8 km below the surface in a basin in South Africa. The results show the possibility of maintaining the modeled ecosystem based on the proposed scenarios and provides directions for future models and exploration missions for a more complete evaluation of the habitability of Europa and of icy moons in general.

  5. High Potential Source for Biomass Degradation Enzyme Discovery and Environmental Aspects Revealed through Metagenomics of Indian Buffalo Rumen

    Directory of Open Access Journals (Sweden)

    K. M. Singh

    2014-01-01

    Full Text Available The complex microbiomes of the rumen functions as an effective system for plant cell wall degradation, and biomass utilization provide genetic resource for degrading microbial enzymes that could be used in the production of biofuel. Therefore the buffalo rumen microbiota was surveyed using shot gun sequencing. This metagenomic sequencing generated 3.9 GB of sequences and data were assembled into 137270 contiguous sequences (contigs. We identified potential 2614 contigs encoding biomass degrading enzymes including glycoside hydrolases (GH: 1943 contigs, carbohydrate binding module (CBM: 23 contigs, glycosyl transferase (GT: 373 contigs, carbohydrate esterases (CE: 259 contigs, and polysaccharide lyases (PE: 16 contigs. The hierarchical clustering of buffalo metagenomes demonstrated the similarities and dissimilarity in microbial community structures and functional capacity. This demonstrates that buffalo rumen microbiome was considerably enriched in functional genes involved in polysaccharide degradation with great prospects to obtain new molecules that may be applied in the biofuel industry.

  6. Biomass Burning:Significant Source of Nitrate and Sulfate for the Andean Rain Forest in Ecuador

    Science.gov (United States)

    Fabian, P.; Rollenbeck, R.; Spichtinger, N.

    2009-04-01

    Forest fires are significant sources of carbon, sulfur and nitrogen compounds which, along with their photochemically generated reaction products, can be transported over very long distances, even traversing oceans. Chemical analyses of rain and fogwater samples collected on the wet eastern slopes of the Ecuadorian Andes show frequent episodes of high sulfate and nitrate concentration, from which annual deposition rates of about14 kg/ha and 7 kg/ha ,respectively, are derived. These are comparable to those observed in polluted central Europe. Regular rain and fogwater sampling along an altitude profile between 1800 and 3185 m, has been carried out since 2002.The research area located at 30 58'S ,790 5' W is dominated by trade winds from easterly directions. The samples, generally accumulated over 1-week intervals, were analysed for pH, conductivity and major ions(K+,Na+,NH4+,Ca2+,Mg 2+,SO42-,NO3-,PO43-).For all components a strong seasonal variation is observed, while the altitudinal gradient is less pronounced. About 65 % of the weekly samples were significantly loaded with cations and anions, with pH often as low 3.5 to 4.0 and conductivity up to 50 uS/cm. Back trajectories (FLEXTRA) showed that respective air masses had passed over areas of intense biomass burning, sometimes influenced by volcanoes, ocean spray, or even episodic Sahara and/or Namib desert dust interference not discussed here. Enhanced SO4 2-and NO3- were identified, by combining satellite-based fire pixels with back trajectories, as predominantly resulting from biomass burning. For most cases, by using emission inventories, anthropogenic precursor sources other than forest fires play a minor role, thus leaving biomass burning as the main source of nitrate and sulphate in rain and fogwater. Some SO4 2- , about 10 % of the total input, could be identified to originate from active volcanoes, whose plumes were sometimes encountered by the respective back trajectories. While volcanic, oceanic and

  7. Ammonia production from amino acid-based biomass-like sources by engineered Escherichia coli.

    Science.gov (United States)

    Mikami, Yosuke; Yoneda, Hisanari; Tatsukami, Yohei; Aoki, Wataru; Ueda, Mitsuyoshi

    2017-12-01

    The demand for ammonia is expected to increase in the future because of its importance in agriculture, industry, and hydrogen transportation. Although the Haber-Bosch process is known as an effective way to produce ammonia, the process is energy-intensive. Thus, an environmentally friendly ammonia production process is desired. In this study, we aimed to produce ammonia from amino acids and amino acid-based biomass-like resources by modifying the metabolism of Escherichia coli. By engineering metabolic flux to promote ammonia production using the overexpression of the ketoisovalerate decarboxylase gene (kivd), derived from Lactococcus lactis, ammonia production from amino acids was 351 mg/L (36.6% yield). Furthermore, we deleted the glnA gene, responsible for ammonia assimilation. Using yeast extract as the sole source of carbon and nitrogen, the resultant strain produced 458 mg/L of ammonia (47.8% yield) from an amino acid-based biomass-like material. The ammonia production yields obtained are the highest reported to date. This study suggests that it will be possible to produce ammonia from waste biomass in an environmentally friendly process.

  8. Decomposition of organic matter labelled with 14C, and microbial biomass formation in an acid soil from Piracicaba, Sao Paulo State, Brazil

    International Nuclear Information System (INIS)

    Cerri, C.C.; Volkoff, B.

    1982-01-01

    An experiment was carried out under laboratory conditions (25 0 C, 50% field capacity), using 14 C labelled sugar cane leaves, which were incorporated to a medium texture Dark-Red Latosol. The equivalent of 1 mg C/g was added to soil containing 14 mg native soil carbon. CO 2 release and microbial biomass were periodically determined. After 67 days incubation it was noted that release of native carbon was greater from soil with plant material than the control (724 μg C/g vs 424 μg/g) and that 25% of the incorporated carbon had been mineralized. Addition of plant material doubled the soil microbial biomass, which was formed due to plant material addition rather than to native soil carbon. (Author) [pt

  9. Characteristics of Ampel bamboo as a biomass energy source potential in Bali

    Science.gov (United States)

    Sucipta, M.; Putra Negara, D. N. K.; Tirta Nindhia, T. G.; Surata, I. W.

    2017-05-01

    Currently, non-renewable fossil energy dominates utilization of the world energy need for many applications. Efforts has been developed to find alternative renewable energy sources, due to fossil energy availability is diminishing. And one of renewable energy source is from biomass. The aim of this research is to determine characteristics of the Ampel bamboo (Bambusa vulgaris) as an energy potential of biomass. The Ampel bamboo’s characteristics possessed are evaluated based on its chemical composition; moisture, volatile, ash, and fixed carbon through proximate analysis; and also carbon, hydrogen and nitrogen content through ultimate analysis. From the Thermo-gravimetric analysis (TGA) indicates that Ampel bamboo contains of about 18.10% hemicelluloses, 47.75% cellulose and 18.86% lignin. While from the ultimate analysis results in the content of carbon, hydrogen, and Nitrogen of Ampel bamboo are 39.75%, 5.75% and 0% respectively. With such characteristics, it indicates that Ampel bamboo has an attractive potential as a renewable energy source.

  10. Decay of Fecal Indicator Bacteria and Microbial Source Tracking Markers in Cattle Feces

    Science.gov (United States)

    The survival of fecal indicator bacteria (FIB) and microbial source tracking (MST) markers in water microcosms and manure amended soils has been well documented; however, little is known about the survival of MST markers in bovine feces deposited on pastures. We conducted a study...

  11. Fecal indicator organism modeling and microbial source tracking in environmental waters: Chapter 3.4.6

    Science.gov (United States)

    Nevers, Meredith; Byappanahalli, Muruleedhara; Phanikumar, Mantha S.; Whitman, Richard L.

    2016-01-01

    Mathematical models have been widely applied to surface waters to estimate rates of settling, resuspension, flow, dispersion, and advection in order to calculate movement of particles that influence water quality. Of particular interest are the movement, survival, and persistence of microbial pathogens or their surrogates, which may contaminate recreational water, drinking water, or shellfish. Most models devoted to microbial water quality have been focused on fecal indicator organisms (FIO), which act as a surrogate for pathogens and viruses. Process-based modeling and statistical modeling have been used to track contamination events to source and to predict future events. The use of these two types of models require different levels of expertise and input; process-based models rely on theoretical physical constructs to explain present conditions and biological distribution while data-based, statistical models use extant paired data to do the same. The selection of the appropriate model and interpretation of results is critical to proper use of these tools in microbial source tracking. Integration of the modeling approaches could provide insight for tracking and predicting contamination events in real time. A review of modeling efforts reveals that process-based modeling has great promise for microbial source tracking efforts; further, combining the understanding of physical processes influencing FIO contamination developed with process-based models and molecular characterization of the population by gene-based (i.e., biological) or chemical markers may be an effective approach for locating sources and remediating contamination in order to protect human health better.

  12. Psychrophilic Biomass Producers in the Trophic Chain of the Microbial Community of Lake Untersee, Antarctica

    Science.gov (United States)

    Pikuta, Elena V.; Hoover, Richard B.

    2010-01-01

    The study of photosynthetic microorganisms from the Lake Untersee samples showed dispersed distribution of phototrophs within 80 m water column. Lake Untersee represents a unique ecosystem that experienced complete isolation: sealed by the Anuchin Glacier for many millennia. Consequently, its biocenosis has evolved over a significant period of time without exchange or external interaction with species from other environments. The major producers of organic matter in Lake Untersee are represented by phototrophic and chemolithotrophic microorganisms. This is the traditional trophic scheme for lacustrine ecosystems on Earth. Among the phototrophs, diatoms were not found, which differentiates this lake from other known ecosystems. The dominant species among phototrophs was Chlamydomonas sp. with typical morphostructure: green chloroplasts, bright red round spot, and two polar flagella near the opening. As expected, the physiology of studied phototrophs was limited by low temperature, which defined them as obligate psychrophilic microorganisms. By the quantity estimation of methanogenesis in this lake, the litho-autotrophic production of organic matter is competitive with phototrophic production. However, pure cultures of methanogens have not yet been obtained. We discuss the primary producers of organic matter and the participation of our novel psychrophilic homoacetogen into the litho-autotrophic link of biomass production in Lake Untersee.

  13. Effects of heavy metals and soil physicochemical properties on wetland soil microbial biomass and bacterial community structure.

    Science.gov (United States)

    Zhang, Chang; Nie, Shuang; Liang, Jie; Zeng, Guangming; Wu, Haipeng; Hua, Shanshan; Liu, Jiayu; Yuan, Yujie; Xiao, Haibing; Deng, Linjing; Xiang, Hongyu

    2016-07-01

    Heavy metals (HMs) contamination is a serious environmental issue in wetland soil. Understanding the micro ecological characteristic of HMs polluted wetland soil has become a public concern. The goal of this study was to identify the effects of HMs and soil physicochemical properties on soil microorganisms and prioritize some parameters that contributed significantly to soil microbial biomass (SMB) and bacterial community structure. Bacterial community structure was analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). Relationships between soil environment and microorganisms were analyzed by correlation analysis and redundancy analysis (RDA). The result indicated relationship between SMB and HMs was weaker than SMB and physicochemical properties. The RDA showed all eight parameters explained 74.9% of the variation in the bacterial DGGE profiles. 43.4% (contain the variation shared by Cr, Cd, Pb and Cu) of the variation for bacteria was explained by the four kinds of HMs, demonstrating HMs contamination had a significant influence on the changes of bacterial community structure. Cr solely explained 19.4% (pstructure, and Cd explained 17.5% (pstructure changes. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Fluctuation of microbial activities after influent load variations in a full-scale SBR. Recovery of the biomass after starvation

    Energy Technology Data Exchange (ETDEWEB)

    Cabezas, Angela; Draper, Patricia; Etchebehere, Claudia [Universidad de la Republica, Montevideo (Uruguay). Catedra de Microbiologia, Facultad de Quimica y Facultad de Ciencias

    2009-10-15

    Due to variations in the production levels, a full-scale sequencing batch reactor (SBR) for post-treatment of tannery wastewater was exposed to low and high ammonia load periods. In order to study how these changes affected the N-removal capacity, the microbiology of the reactor was studied by a diverse set of techniques including molecular tools, activity tests, and microbial counts in samples taken along 3 years. The recover capacity of the biomass was also studied in a lab-scale reactor operated with intermittent aeration without feeding for 36 days. The results showed that changes in the feeding negatively affected the nitrifying community, but the nitrogen removal efficiencies could be restored after the concentration stress. Species substitution was observed within the nitrifying bacteria, Nitrosomonas europaea and Nitrobacter predominated initially, and after an ammonia overload period, Nitrosomonas nitrosa and Nitrospira became dominant. Some denitrifiers, with nirS related to Alicycliphilus, Azospirillum, and Marinobacter nirS, persisted during long-term reactor operation, but the community fluctuated both in composition and in abundance. This fluctuating community may better resist the continuous changes in the feeding regime. Our results showed that a nitrifying-denitrifying SBR could be operated with low loads or even without feeding during production shut down periods. (orig.)

  15. Immobilization of microbial cell and yeast cell and its application to biomass conversion using radiation techniques

    International Nuclear Information System (INIS)

    Kaetsu, Isao; Kumakura, Minoru; Fujimura, Takashi; Kasai, Noboru; Tamada, Masao

    1987-01-01

    The recent results of immobilization of cellulase-producing cells and ethanol-fermentation yeast by radiation were reported. The enzyme of cellulase produced by immobilized cells was used for saccharification of lignocellulosic wastes and immobilized yeast cells were used for fermentation reaction from glucose to ethanol. The wastes such as chaff and bagasse were treated by γ-ray or electron-beam irradiation in the presence of alkali and subsequent mechanical crushing, to form a fine powder less than 50 μm in diameter. On the other hand, Trichoderma reesei as a cellulase-producing microbial cell was immobilized on a fibrous carrier having a specific porous structure and cultured to produce cellulase. The enzymatic saccharification of the pretreated waste was carried out using the produced cellulase. The enhanced fermentation process to produce ethanol from glucose with the immobilized yeast by radiation was also studied. The ethanol productivity of immobilized growing yeast cells thus obtained was thirteen times that of free yeast cells in a 1:1 volume of liquid medium to immobilized yeast cells. (author)

  16. Immobilization of microbial cell and yeast cell and its application to biomass conversion using radiation techniques

    Science.gov (United States)

    Kaetsu, Isao; Kumakura, Minoru; Fujimura, Takashi; Kasai, Noboru; Tamada, Masao

    The recent results of immobilization of cellulase-producing cells and ethanol-fermentation yeast by radiation were reported. The enzyme of cellulase produced by immobilized cells was used for saccharification of lignocellulosic wastes and immobilized yeast cells were used for fermentation reaction from glucose to ethanol. The wastes such as chaff and bagasse were treated by γ-ray or electron-beam irradiation in the presence of alkali and subsequent mechanical crushing, to form a fine powder less than 50 μm in diameter. On the other hand, Trichoderma reesei as a cellulase-producing microbial cell was immobilized on a fibrous carrier having a specific porous structure and cultured to produce cellulase. The enzymatic saccharification of the pretreated waste was carried out using the produced cellulase. The enhanced fermentation process to produce ethanol from glucose with the immobilized yeast by radiation was also studied. The ethanol productivity of immobilized growing yeast cells thus obtained was thirteen times that of free yeast cells in a 1:1 volume of liquid medium to immobilized yeast cells.

  17. RELATIONSHIPS BETWEEN SOIL MICROBIAL BIOMASS, AGGREGATE STABILITY AND AGGREGATE ASSOCIATED-C: A MECHANISTIC APPROACH

    Directory of Open Access Journals (Sweden)

    Patrizia Guidi

    2014-01-01

    Full Text Available For the identification of C pools involved in soil aggregation, a physically-based aggregate fractionation was proposed, and  additional pretreatments were used in the measurement of the 1-2 mm aggregate stability in order to elucidate the relevance of the role of soil microorganisms with respect to the different aggregate breakdown mechanisms. The study was carried out on three clay loam Regosols, developed on calcareous shales, known history of organic cultivation.Our results showed that the soil C pool controlling the process of stabilisation of aggregates was related to the microbial community. We identified the resistance to fast wetting as the major mechanism of aggregate stability driven by microorganims. The plausible hypothesis is that organic farming promotes fungi growth, improving water repellency of soil aggregates by fungal hydrophobic substances. By contrast, we failed in the identification of C pools controlling the formation of aggregates, probably because of the disturbance of mechanical tillage which contributes to the breakdown of soil aggregates.The physically-based aggregate fractionation proposed in this study resulted useful in the  mechanistically understanding of the role of microorganisms in soil aggregation and it might be suggested for studying the impact of management on C pools, aggregates properties and their relationships in agricultural soils.

  18. Biomass Energy Basics | NREL

    Science.gov (United States)

    Biomass Energy Basics Biomass Energy Basics We have used biomass energy, or "bioenergy" keep warm. Wood is still the largest biomass energy resource today, but other sources of biomass can landfills (which are methane, the main component in natural gas) can be used as a biomass energy source. A

  19. Spatial distribution of microbial biomass, activity, community structure, and the biodegradation of linear alkylbenzene sulfonate (LAS) and linear alcohol ethoxylate (LAE) in the subsurface.

    Science.gov (United States)

    Federle, T W; Ventullo, R M; White, D C

    1990-12-01

    The vertical distribution of microbial biomass, activity, community structure and the mineralization of xenobiotic chemicals was examined in two soil profiles in northern Wisconsin. One profile was impacted by infiltrating wastewater from a laundromat, while the other served as a control. An unconfined aquifer was present 14 meters below the surface at both sites. Biomass and community structure were determined by acridine orange direct counts and measuring concentrations of phospholipid-derived fatty acids (PLFA). Microbial activity was estimated by measuring fluorescein diacetate (FDA) hydrolysis, thymidine incorporation into DNA, and mixed amino acid (MAA) mineralization. Mineralization kinetics of linear alkylbenzene sulfonate (LAS) and linear alcohol ethoxylate (LAE) were determined at each depth. Except for MAA mineralization rates, measures of microbial biomass and activity exhibited similar patterns with depth. PLFA concentration and rates of FDA hydrolysis and thymidine incorporation decreased 10-100 fold below 3 m and then exhibited little variation with depth. Fungal fatty acid markers were found at all depths and represented from 1 to 15% of the total PLFAs. The relative proportion of tuberculostearic acid (TBS), an actinomycete marker, declined with depth and was not detected in the saturated zone. The profile impacted by wastewater exhibited higher levels of PLFA but a lower proportion of TBS than the control profile. This profile also exhibited faster rates of FDA hydrolysis and amino acid mineralization at most depths. LAS was mineralized in the upper 2 m of the vadose zone and in the saturated zone of both profiles. Little or no LAS biodegradation occurred at depths between 2 and 14 m. LAE was mineralized at all depths in both profiles, and the mineralization rate exhibited a similar pattern with depth as biomass and activity measurements. In general, biomass and biodegradative activities were much lower in groundwater than in soil samples obtained

  20. Microbial biomass, community structure and metal tolerance of a naturally Pb-enriched forest soil.

    Science.gov (United States)

    Bååth, E; Díaz-Raviña, M; Bakken, L R

    2005-11-01

    The effect of long-term elevated soil Pb levels on soil microbiota was studied at a forest site in Norway, where the soil has been severely contaminated with Pb since the last period of glaciation (several thousand years). Up to 10% Pb (total amount, w/w) has been found in the top layer. The microbial community was drastically affected, as judged from changes in the phospholipid fatty acid (PLFA) pattern. Specific PLFAs that were high in Pb-enriched soil were branched (especially br17:0 and br18:0), whereas PLFAs common in eukaryotic organisms such as fungi (18:2omega6,9 and 20:4) were low compared with levels at adjacent, uncontaminated sites. Congruent changes in the PLFA pattern were found upon analyzing the culturable part of the bacterial community. The high Pb concentrations in the soil resulted in increased tolerance to Pb of the bacterial community, measured using both thymidine incorporation and plate counts. Furthermore, changes in tolerance were correlated to changes in the community structure. The bacterial community of the most contaminated soils showed higher specific activity (thymidine and leucine incorporation rates) and higher culturability than that of control soils. Fungal colony forming units (CFUs) were 10 times lower in the most Pb-enriched soils, the species composition was widely different from that in control soils, and the isolated fungi had high Pb tolerance. The most commonly isolated fungus in Pb-enriched soils was Tolypocladium inflatum. Comparison of isolates from Pb-enriched soil and isolates from unpolluted soils showed that T. inflatum was intrinsically Pb-tolerant, and that the prolonged conditions with high Pb had not selected for any increased tolerance.

  1. New microbial source of the antifungal allylamine “Terbinafine”

    Directory of Open Access Journals (Sweden)

    Maged S. Abdel-Kader

    2017-03-01

    Full Text Available The isolated active compound “F12” from the culture media of the Streptomyces sp. KH-F12 was identified using different spectroscopic techniques. Both 1D- and 2D-NMR as well as HRESIMS were utilized to characterize the structure of the isolated compound. ‘F12” was found to be the known systemic antifungal drug terbinafine marketed under the name “Lamisil”. Full analysis of the COSY, HSQC and HMBC enables the full assignment of proton and carbon atoms. Terbinafine is a synthetic allylamine and is reported here for the first time from natural source.

  2. A Model of the Effect of the Microbial Biomass on the Isotherm of the Fermenting Solids in Solid-State Fermentation

    Directory of Open Access Journals (Sweden)

    Barbara Celuppi Marques

    2006-01-01

    Full Text Available We compare isotherms for soybeans and soybeans fermented with Rhizopus oryzae, showing that in solid-state fermentation the biomass affects the isotherm of the fermenting solids. Equations are developed to calculate, for a given overall water content of the fermenting solids, the water contents of the biomass and residual substrate, as well as the water activity. A case study, undertaken using a mathematical model of a well-mixed bioreactor, shows that if water additions are made on the basis of the assumption that fermenting solids have the same isotherm as the substrate itself, poor growth can result since the added water does not maintain the water activity at levels favorable for growth. We conclude that the effect of the microbial biomass on the isotherm of the fermenting solids must be taken into account in mathematical models of solid-state fermentation bioreactors.

  3. Effects of lead contamination on soil enzymatic activities, microbial biomass, and rice physiological indices in soil-lead-rice (Oryza sativa L.) system.

    Science.gov (United States)

    Zeng, Lu S; Liao, Min; Chen, Cheng L; Huang, Chang Y

    2007-05-01

    The effect of lead (Pb) treatment on the soil enzymatic activities, soil microbial biomass, rice physiological indices and rice biomass were studied in a greenhouse pot experiment. Six levels of Pb viz. 0(CK), 100, 300, 500, 700, 900 mg/kg soil were applied in two types of paddy soils. The results showed that Pb treatment had a stimulating effect on soil enzymatic activities and microbial biomass carbon (Cmic) at low concentration and an inhibitory influence at higher concentration. The degree of influence on enzymatic activities and Cmic by Pb was related to the clay and organic matter contents of the soils. When the Pb treatment was raised to the level of 500 mg/kg, ecological risk appeared both to soil microorganisms and plants. The results also revealed a consistent trend of increased chlorophyll contents and rice biomass initially, maximum at a certain Pb treatment, and then decreased gradually with the increase in Pb concentration. Pb was effective in inducing proline accumulation and its toxicity causes oxidative stress in rice plants. Therefore, it was concluded that soil enzymatic activities, Cmic and rice physiological indices, could be sensitive indicators to reflect environmental stress in soil-lead-rice system.

  4. Dynamics of microbial biomass and respiratory activity during late summer in a site of Arctic Kongsfjorden

    Directory of Open Access Journals (Sweden)

    Rosabruna La Ferla

    2014-06-01

    The Kongsfjorden was affected by inflow of Atlantic water as well as glacier melt water runoff (Cottier et al., 2005. The experiment comprised 5 samplings performed during a 7 day period in MDI station. For each sampling, photosynthetically active radiation (PAR, temperature and conductivity (salinity were recorded along the water column with a PNF-300 profiler and a SeaBird Electronics SBE-911 plus profiler, respectively . Water samples were taken at five different depths (surface, 5, 25, 50 and 100 m to determine nutrients, particulate organic carbon, prokaryotes and phytoplankton biomass, and community respiration. In addition, prokaryotes sunk with the particulate matter were studied into the sediment trap positioned in the MDI during the period between June and September 2013. The latter assessment allowed us to determine the flow of prokaryotes, conveyed from organic matter sinking, throughout the summer. Due to melting of the glaciers in the surface water of the study site, there were sediment loads which strongly limited light penetration and low irradiance (~0.7% E0+ at 5 meters below the surface. Along the water column the intrusion of the salty and warm Atlantic water was visible in the study site and the warm core was at about 25 m depth. PO4 concentrations ranged between 0.43 (surface and 1 µM (100 m and in general the values increased from surface to bottom. NH4, NO2 and NO3 significantly changed along the vertical and with time and varied between 0.39 and 5.05µM, 0.01 and 0.67µM, 0.001 and 4.18µM, respectively. Prokaryotic abundances and cell volumes ranged between 5.6 and 15.9 E+05 cells ml-1 and 0.033 and 0.093 µm3, respectively. These latter parameters showed a peak at 25 m depth in the core of incoming Atlantic water. This evidence was not determined in chlorophyll a (range 0.034-1.102 mg m-3, where the highest values were determined at the surface and 5 m depth. Speculations will be made on the variability of the fluxes of carbon

  5. Engineering a Synthetic Microbial Consortium for Comprehensive Conversion of Algae Biomass into Terpenes for Advanced Biofuels and Bioproducts

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Weihua [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Wu, Benjamin Chiau-Pin [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Davis, Ryan Wesley [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2015-10-01

    Recent strategies for algae-based biofuels have primarily focused on biodiesel production by exploiting high algal lipid yields under nutrient stress conditions. However, under conditions supporting robust algal biomass accumulation, carbohydrate and proteins typically comprise up to ~80% of the ash-free dry weight of algae biomass. Therefore, comprehensive utilization of algal biomass for production of multipurpose intermediate- to high-value bio-based products will promote scale-up of algae production and processing to commodity volumes. Terpenes are hydrocarbon and hydrocarbon-like (C:O>10:1) compounds with high energy density, and are therefore potentially promising candidates for the next generation of value added bio-based chemicals and “drop-in” replacements for petroleum-based fuels. In this study, we demonstrated the feasibility of bioconversion of proteins into sesquiterpene compounds as well as comprehensive bioconversion of algal carbohydrates and proteins into biofuels. To achieve this, the mevalonate pathway was reconstructed into an E. coli chassis with six different terpene synthases (TSs). Strains containing the various TSs produced a spectrum of sesquiterpene compounds in minimal medium containing amino acids as the sole carbon source. The sesquiterpene production was optimized through three different regulation strategies using chamigrene synthase as an example. The highest total terpene titer reached 166 mg/L, and was achieved by applying a strategy to minimize mevalonate accumulation in vivo. The highest yields of total terpene were produced under reduced IPTG induction levels (0.25 mM), reduced induction temperature (25°C), and elevated substrate concentration (20 g/L amino acid mixture). A synthetic bioconversion consortium consisting of two engineering E. coli strains (DH1-TS and YH40-TS) with reconstructed terpene biosynthetic pathways was designed for comprehensive single-pot conversion of algal carbohydrates and proteins to

  6. Microbial production of poly(hydroxybutyrate) from C₁ carbon sources.

    Science.gov (United States)

    Khosravi-Darani, Kianoush; Mokhtari, Zahra-Beigom; Amai, Tomohito; Tanaka, Kenji

    2013-02-01

    Polyhydroxybutyrate (PHB) is an attractive substitute for petrochemical plastic due to its similar properties, biocompatibility, and biodegradability. The cost of scaled-up PHB production inhibits its widespread usage. Intensive researches are growing to reduce costs and improve thermomechanical, physical, and processing properties of this green biopolymer. Among cheap substrates which are used for reducing total cost of PHB production, some C₁ carbon sources, e.g., methane, methanol, and CO₂ have received a great deal of attention due to their serious role in greenhouse problem. This article reviews the fundamentals of strategies for reducing PHA production and moves on to the applications of several cheap substrates with a special emphasis on methane, methanol, and CO₂. Also, some explanation for involved microorganisms including the hydrogen-oxidizing bacteria and methanotrophs, their history, culture condition, and nutritional requirements are given. After description of some important strains among the hydrogen-oxidizing and methanotrophic producers of PHB, the article is focused on limitations, threats, and opportunities for application and their future trends.

  7. Soil microbial biomass in organic farming system Biomassa microbiana do solo em sistemas orgânicos

    Directory of Open Access Journals (Sweden)

    Ademir Sérgio Ferreira de Araújo

    2010-11-01

    Full Text Available Agricultural production systems have to combine management practices in order to sustain soil's profitability and quality. Organic farming is gaining worldwide acceptance and has been expanding at an annual rate of 20% in the last decade, accounting for over 24 million hectares worldwide. Organic practices avoid applications of synthetic fertilizers and pesticides, rely on organic inputs and recycling for nutrient supply, and emphasize cropping system design and biological processes for pest management, as defined by organic farming regulation in the world. In comparison with conventional farming, organic farming has potential benefits in improving food quality and safety. Plant production in organic farming mainly depends on nutrient release as a function of mineralization processes in soils. The build-up of a large and active soil microbial biomass is important pool of accessible nutrients, therefore, is an important priority in organic farming. In organic farming, there is positive effect of quantity and quality of inputs of organic residues on soil microbial biomass. In this way, the organic systems are extremely important for the increase of the soil fertility and the maintenance of the environmental sustainability.A produção agrícola tem de combinar práticas para prover a sustentabilidade do solo. A agricultura orgânica está ganhando aceitação mundial e cresce à taxa anual de 20% na última década, contabilizando mais de 24 milhões de hectares. As práticas orgânicas evitam o uso de fertilizantes sintéticos e pesticidas, enfatiza a aplicação de matéria orgânica, como também a reciclagem de nutrientes e de processos biológicos para manejo de pragas, através das regras dos sistemas orgânicos no mundo. Em comparação com a agricultura convencional, os sistemas orgânicos têm potencial de melhorar a qualidade e a segurança dos alimentos. A produção das plantas no sistema orgânico depende da liberação de nutrientes

  8. Biochar amendment decreases soil microbial biomass and increases bacterial diversity in Moso bamboo (Phyllostachys edulis) plantations under simulated nitrogen deposition

    Science.gov (United States)

    Li, Quan; Lei, Zhaofeng; Song, Xinzhang; Zhang, Zhiting; Ying, Yeqing; Peng, Changhui

    2018-04-01

    Biochar amendment has been proposed as a strategy to improve acidic soils after overuse of nitrogen fertilizers. However, little is known of the role of biochar in soil microbial biomass carbon (MBC) and bacterial community structure and diversity after soil acidification induced by nitrogen (N) deposition. Using high-throughput sequencing of the 16S rRNA gene, we determined the effects of biochar amendment (BC0, 0 t bamboo biochar ha‑1 BC20, 20 t bamboo biochar ha‑1 and BC40, 40 t bamboo biochar ha‑1) on the soil bacterial community structure and diversity in Moso bamboo plantations that had received simulated N deposition (N30, 30 kg N ha‑1 yr‑1 N60, 60 kg N ha‑1 yr‑1 N90, 90 kg N ha‑1 yr‑1 and N-free) for 21 months. After treatment of N-free plots, BC20 significantly increased soil MBC and bacterial diversity, while BC40 significantly decreased soil MBC but increased bacterial diversity. When used to amend N30 and N60 plots, biochar significantly decreased soil MBC and the reducing effect increased with biochar amendment amount. However, these significant effects were not observed in N90 plots. Under N deposition, biochar amendment largely increased soil bacterial diversity, and these effects depended on the rates of N deposition and biochar amendment. Soil bacterial diversity was significantly related to the soil C/N ratio, pH, and soil organic carbon content. These findings suggest an optimal approach for using biochar to offset the effects of N deposition in plantation soils and provide a new perspective for understanding the potential role of biochar amendments in plantation soil.

  9. Good Manufacturing Practices and Microbial Contamination Sources in Orange Fleshed Sweet Potato Puree Processing Plant in Kenya

    OpenAIRE

    Malavi, Derick Nyabera; Muzhingi, Tawanda; Abong’, George Ooko

    2018-01-01

    Limited information exists on the status of hygiene and probable sources of microbial contamination in Orange Fleshed Sweet Potato (OFSP) puree processing. The current study is aimed at determining the level of compliance to Good Manufacturing Practices (GMPs), hygiene, and microbial quality in OFSP puree processing plant in Kenya. Intensive observation and interviews using a structured GMPs checklist, environmental sampling, and microbial analysis by standard microbiological methods were use...

  10. Influence of organic waste and inorganic nitrogen source on biomass productivity of Scenedesmus and Chlorococcum sp.

    Energy Technology Data Exchange (ETDEWEB)

    Arumugam, M.; Agarwal, A.; Arya, M.C. [Defence Institute of Bio-Energy Research, Defence R and D Organization, Ministry of Defence, Govt. of India, Field Station Pithoragarh - 262501, Uttarakhand (India); Ahmed, Z. [Defence Institute of Bio-Energy Research, Defence R and D Organization, Ministry of Defence, Govt. of India Haldwani- 263 139, Uttarakhand (India)

    2011-07-01

    Algae gaining the more attention in the recent years in order to supplement the futuristic demand of fuel requirement because of its unique feature like high productivity, short duration and higher fatty acids content. However algal culturing for large-scale production is limited due to many technical and engineering challenges. One of the main constraints for large-scale biomass production is the non-availability of cost effective and affordable growth medium for open pond condition. In order to overcome this lacuna, the present study was carried out to find out the suitable cost effective growth medium using locally available resources. Farm Yard Manure an easily available organic waste yet, rich in nutrients and used for agriculture over the generations. FYM coupled with inorganic nitrogen source like urea was found to be better alternative to the synthetic growth medium, which may make wider acceptability at farmers' field for large-scale algal mass production. The present study reveals that FYM extract of 50% supplemented with 0.1% Urea was performing better for algal biomass growth in outdoor open pond condition.

  11. Assessing the Effect of Prometryn Soil Residue on Soil Microbial Biomass and Different Crops using Bioassay Test

    Directory of Open Access Journals (Sweden)

    mohamad taghi alebrahim

    2016-09-01

    after germination. The pots were kept for 30 days under controlled conditions. Shoot and root biomass production was measured 30 days after emergence. At harvest, growth parameters including the dry weight of shoots and roots were determined. The data were subjected to analysis of variance by computer facilities, using Mstatc software. Plant response to prometryn residues was fitted with sigmoidal 3 and 4 parametric equations to the shoot biomass data as a function of the herbicide residue concentrations and was used to calculate the doses for 50% inhibition of shoot growth (ED50. In another experiment the effect of prometryn concentrations (0, 0.0033, 0.0166, 0.033, 0.066, 0.1 and 0.166 mg. kg-1soil on soil microbial activity was determined using titration method in controlled conditions. Results and Discussion: Plant response to increasing concentration of prometryn, in general, followed a classical dose response relationship. The logistic model fitted well to the root and shoot plants response herbicide concentrations. Results showed that the shoot and root dry matter were significantly affected by increasing prometryn soil residue in all crops (plettuce>beet>barely. Based on the mechanism of action of prometryn and its best efficiency on board leaf plants control, the least biomass reduction obtained for barley is understandable. In general, this is safe to plant a susceptible species if the plant-available residue were less than the species ED10 value, and there would be a great risk for different levels of crop damage if the plant-available residue were higher than ED50 values of the species. Comparisons between species allow the safe selection of a crop that has a critical ED50 level lower than the residue level in the soil. Alternatively, planting a sensitive species could be delayed until the residue level in the soil is less than the critical level. In the Southwest areas of Iran, these crops are often sown few months after the application of a residual

  12. Effects of different sources of organic waste application on the growth and biomass production of kenaf (hibiscus cannabinus L.)

    International Nuclear Information System (INIS)

    Shahariara, M.S.; Tahsina, S.; Muhammad, S.; Gani, M.N.; Huq, I.

    2012-01-01

    The growth and biomass productivity of kenaf (Hibiscus cannabinus L.) grown with different sources of organic waste viz. sewage sludge, poultry litter, cow dung and rice straw application were observed in a field experiment. Organic wastes were applied at the rate of 5 t/ha and were compared with recommended dose of fertilizers and control. The plants were harvested at 120 days after sowing (at the flowering stage). Different sources of organic wastes had a significant effect (P cow dung>poultry litter > rice straw treatments. Among the four sources of organic wastes, sewage sludge treated plot produced the highest mean biomass of 23.33 t/ha (dry weight basis) which was 14.64% higher than the mean biomass production from control plot. (author)

  13. Effects of different sources of organic waste application on the growth and biomass production of kenaf (hibiscus cannabinus L.)

    International Nuclear Information System (INIS)

    Shahariar, M.S.; Tashin, S.; Gani, N.; Muhammad, S.; Huq, I.

    2012-01-01

    The growth and biomass productivity of kenaf(Hibiscus cannabinus L.) grown with different sources of organic waste viz. sewage sludge, poultry litter, cow dung and rice straw application were observed in a field experiment. Organic wastes were applied at the rate of 5 t/ha and were compared with recommended dose of fertilizers and control. The plants were harvested at 120 days after sowing (at the flowering stage). Different sources of organic wastes had a significant effect (P cow dung>poultry litter> rice straw treatments. Among the four sources of organic wastes, sewage sludge treated plot produced the highest mean biomass of 23.33 t/ha (dry weight basis) which was 14.64% higher than the mean biomass production from control plot. (author)

  14. Advanced system demonstration for utilization of biomass as an energy source. Environmental report

    Energy Technology Data Exchange (ETDEWEB)

    McCollom, M.

    1979-01-01

    The conclusions and findings of extensive analyses undertaken to assess the environmental impacts and effects of the proposal to assist in an Advanced System Demonstration for Utilization of Biomass as an Energy Source by means of a wood-fueled power plant. Included are a description of the proposed project, a discussion of the existing environment that the project would affect, a summary of the project's impacts on the natural and human environments, a discussion of the project's relationships to other government policies and plans, and an extensive review of the alternatives which were considered in evaluating the proposed action. All findings of the research undertaken are discussed. More extensive presentations of the methods of analysis used to arrive at the various conclusions are available in ten topical technical appendices.

  15. Structural stability, microbial biomass and community composition of sediments affected by the hydric dynamics of an urban stormwater infiltration basin. Dynamics of physical and microbial characteristics of stormwater sediment.

    Science.gov (United States)

    Badin, Anne Laure; Monier, Armelle; Volatier, Laurence; Geremia, Roberto A; Delolme, Cécile; Bedell, Jean-Philippe

    2011-05-01

    The sedimentary layer deposited at the surface of stormwater infiltration basins is highly organic and multicontaminated. It undergoes considerable moisture content fluctuations due to the drying and inundation cycles (called hydric dynamics) of these basins. Little is known about the microflora of the sediments and its dynamics; hence, the purpose of this study is to describe the physicochemical and biological characteristics of the sediments at different hydric statuses of the infiltration basin. Sediments were sampled at five time points following rain events and dry periods. They were characterized by physical (aggregation), chemical (nutrients and heavy metals), and biological (total, bacterial and fungal biomasses, and genotypic fingerprints of total bacterial and fungal communities) parameters. Data were processed using statistical analyses which indicated that heavy metal (1,841 μg/g dry weight (DW)) and organic matter (11%) remained stable through time. By contrast, aggregation, nutrient content (NH₄⁺, 53-717 μg/g DW), pH (6.9-7.4), and biological parameters were shown to vary with sediment water content and sediment biomass, and were higher consecutive to stormwater flows into the basin (up to 7 mg C/g DW) than during dry periods (0.6 mg C/g DW). Coinertia analysis revealed that the structure of the bacterial communities is driven by the hydric dynamics of the infiltration basin, although no such trend was found for fungal communities. Hydric dynamics more than rain events appear to be more relevant for explaining variations of aggregation, microbial biomass, and shift in the microbial community composition. We concluded that the hydric dynamics of stormwater infiltration basins greatly affects the structural stability of the sedimentary layer, the biomass of the microbial community living in it and its dynamics. The decrease in aggregation consecutive to rewetting probably enhances access to organic matter (OM), explaining the consecutive release

  16. Numbers, biomass and cultivable diversity of microbial populations relate to depth and borehole-specific conditions in groundwater from depths of 4-450 m in Olkiluoto, Finland.

    Science.gov (United States)

    Pedersen, Karsten; Arlinger, Johanna; Eriksson, Sara; Hallbeck, Anna; Hallbeck, Lotta; Johansson, Jessica

    2008-07-01

    Microbiology, chemistry and dissolved gas in groundwater from Olkiluoto, Finland, were analysed over 3 years; samples came from 16 shallow observation tubes and boreholes from depths of 3.9-16.2 m and 14 deep boreholes from depths of 35-742 m. The average total number of cells (TNC) was 3.9 x 10(5) cells per ml in the shallow groundwater and 5.7 x 10(4) cells per ml in the deep groundwater. There was a significant correlation between the amount of biomass, analysed as ATP concentration, and TNC. ATP concentration also correlated with the stacked output of anaerobic most probable number cultivations of nitrate-, iron-, manganese- and sulphate-reducing bacteria, and acetogenic bacteria and methanogens. The numbers and biomass varied at most by approximately three orders of magnitude between boreholes, and TNC and ATP were positively related to the concentration of dissolved organic carbon. Two depth zones were found where the numbers, biomass and diversity of the microbial populations peaked. Shallow groundwater down to a depth of 16.2 m on average contained more biomass and cultivable microorganisms than did deep groundwater, except in a zone at a depth of approximately 300 m where the average biomass and number of cultivable microorganisms approached those of shallow groundwater. Starting at a depth of approximately 300 m, there were steep gradients of decreasing sulphate and increasing methane concentrations with depth; together with the peaks in biomass and sulphide concentration at this depth, these suggest that anaerobic methane oxidation may be a significant process at depth in Olkiluoto.

  17. Bioethanol Production From Cellulose by Candida tropicalis, as An Alternative Microbial Agent to Produce Ethanol from Lignocellulosic Biomass

    Directory of Open Access Journals (Sweden)

    Hermansyah

    2016-04-01

    Full Text Available Abstract: Candida tropicalis isolated from Tuak is a potentially useful microorganism for the ethanol production from lignocellulosic biomass and it can be alterbative agent replacing Saccharomyces cerevisae for fermentation process. Although C.tropicalis could not convert all carbohydrates content of lignocellulosic into bioethanol, however it is able to grow on medium in the presence of either xylose or arabinose as carbon source. Our result showed that fermentation of 10 % (w/v cellulosic as sole carbon source produced 2.88% (v/v ethanol by C.tropicalis. This ethanol production was lower than usage of 10% (w/v dextrose as sole carbon source medium which producing 5.51% (v/v ethanol. Based upon our expreiment indicated that C.tropicalis is able to conduct two main process in converting of cellulosic material- to ethanol which is hydrolysis the degradation of cellulose into glucose, and fermentation the process the conversion glucose into bioethanol. Keywords : Candida tropicalis, bioethanol, fermentation, cellulosic Abstrak (Indonesian: Candida tropicalis yang diisiolasi dari Tuak adalah agen yang berpotensi dalam produksi etanol dari biomasa lignoselulosa dan dapat dijadikan agen alternatif menggantikan Saccharomyces cerevisiae pada proses fernentasi. Walaupun C.tropicalis tidak dapat mengkonversi semua kandungan karbohidrat lignoselulosamenjadi etanol, akan tetapi C.tropicalis mampu tumbuh pada media dengan xilosa atau arabinosa sebagaisumber karbon. Hasil kami menunjukkan bahwa dengan mengguankan C.tropicalis fermentasi 10% (w/v selulosa sebagai satu-satunya sumber karbon menghasilkan 2,88% (v/v etanol, Produksi etanol ini lebih rendah jika menggunakan 10% (w/v dekstrosa sebagai satu satunya sumber karbon yang menghasilkan 5,51% (v/v etanol. Berdasarkan percobaan menunjukkan bahwa C.tropicalis mampu melakukan dua proses utama dalam mengkonversi material selulosa menjadi etanol yaitu hidrolisis degradasi selulosa menjadi glukosa, dan

  18. Biomassa microbiana em amostras de solos secadas ao ar e reumedecidas Microbial biomass in air dried and rewetted soil samples

    Directory of Open Access Journals (Sweden)

    Antônio Samarão Gonçalves

    2002-05-01

    Full Text Available O objetivo do trabalho foi avaliar a viabilidade do condicionamento de amostras como terra fina secada ao ar (TFSA por curto período, para a determinação do carbono da biomassa microbiana (BMS-C, pelo método da fumigaçãoextração, e verificar a respiração microbiana basal (RB do solo. O condicionamento como TFSA, procedendo-se à fumigação para a análise da BMS-C imediatamente ou 24 horas após o reumedecimento, proporcionou valores de BMS-C para os solos Podzólicos, Latossolo Vermelho-Amarelo álico e Orgânico, semelhantes aos valores dos seus controles. Os solos Glei Pouco Húmico e Vertissolo apresentaram valores de BMS-C similares aos do controle a partir de 24 horas de incubação; o solo Planossolo arenoso apresentou valores similares aos do controle com 72 horas, e a Rendizina, com 168 horas de incubação. Na maioria dos solos, a RB determinada na TFSA apresentou valores maiores do que os do tratamento-controle, quando avaliada imediatamente ou 24 horas após o reumedecimento a 60% da capacidade máxima de retenção de água, seguida de queda e manutenção em níveis semelhantes ao do controle nos períodos subseqüentes. O précondicionamento, de curta duração, como TFSA, é promissor para a determinação da BMS-C, quando níveis e períodos adequados de reumedecimento são adotados.The objective of this work was to evaluate the utilization of short term air dried soil samples in a determination of soil microbial biomass (SMB-C, by a fumigationextraction method, and soil microbial basal respiration (BR. Zero time or 24 hours rewetting incubation period before fumigation procedure gave values of SMB-C similar to those of the control for the Podzolic soils, Allic RedYellow Latosol and Organic soil. Low Humic Gley and Vertisol soils gave values of SMB-C similar to those of the control for periods of incubation equal or higher than 24 hours. Planosol (sandy soil and Rendzina soils gave values of SMB-C similar to the

  19. Synergistic microbial consortium for bioenergy generation from complex natural energy sources.

    Science.gov (United States)

    Wang, Victor Bochuan; Yam, Joey Kuok Hoong; Chua, Song-Lin; Zhang, Qichun; Cao, Bin; Chye, Joachim Loo Say; Yang, Liang

    2014-01-01

    Microbial species have evolved diverse mechanisms for utilization of complex carbon sources. Proper combination of targeted species can affect bioenergy production from natural waste products. Here, we established a stable microbial consortium with Escherichia coli and Shewanella oneidensis in microbial fuel cells (MFCs) to produce bioenergy from an abundant natural energy source, in the form of the sarcocarp harvested from coconuts. This component is mostly discarded as waste. However, through its usage as a feedstock for MFCs to produce useful energy in this study, the sarcocarp can be utilized meaningfully. The monospecies S. oneidensis system was able to generate bioenergy in a short experimental time frame while the monospecies E. coli system generated significantly less bioenergy. A combination of E. coli and S. oneidensis in the ratio of 1:9 (v:v) significantly enhanced the experimental time frame and magnitude of bioenergy generation. The synergistic effect is suggested to arise from E. coli and S. oneidensis utilizing different nutrients as electron donors and effect of flavins secreted by S. oneidensis. Confocal images confirmed the presence of biofilms and point towards their importance in generating bioenergy in MFCs.

  20. Effect of three sources of nutrients on biomass and pigment production of freshwater microalgae Hyaloraphidium contortum

    Directory of Open Access Journals (Sweden)

    Caña, E.

    2016-05-01

    Full Text Available Multifunctionality of microalgae is becoming increasingly important, hence science develops new techniques to maximize their potential by providing food, sustainable and affordable fuels and innovative environmental solutions. In this study, we analyzed the effect of different nutrient sources (Nitrofoska®, Quimifol® and Guillard and sowing time on the kinetics of growth and pigment production of freshwater microalgae Hyaloraphidium contortum; besides of registering some physical and chemical variables in different growth mediums. Bioassays were performed in batch cultures by quadruplicate, continously maintaining and controlling temperature, ventilation and lighting. Growth was determined by cell count and production of pigments by spectrophotometry. The largest population densities and productivities per volume of culture were obtained in F/2 Guillard (9.7±0.2x107 cel mL-1 and 7.6x108 cel/L/ day and Nitrofoska® (8.7±0.5x107 cel mL-1 and 5.7x108 cel/L/day. The highest average chlorophyll a, chlorophyll b and total carotenoid concentration was achieved with foliar fertilizer Nitrofoska®, on days 18 and 24 (8, 3.29 and 2.2 μg mL-1, respectively, followed by the obtained by Guillard and Quimifol®. We conclude that this microalgae can be grown with commercial agricultural fertilizers as an alternative source of nutrients to produce biomass and pigments with applications in biotechnology and aquaculture industries.

  1. Methylmercury in the Gulf of Trieste (Northern Adriatic Sea: From Microbial Sources to Seafood Consumers

    Directory of Open Access Journals (Sweden)

    Mark E. Hines

    2014-01-01

    Full Text Available The Gulf of Trieste (northern Adriatic Sea is one of the most mercury-polluted areas in the Mediterranean and in the world due to the past mining activity in the Idrija region (western Slovenia. The link between microbial production of toxic methylmercury (MeHg, and its bioaccumulation and biomagnification in marine food webs of the gulf is at present rather poorly characterized but is critical to understanding the links between sources and higher trophic levels, such as fish, that are ultimately vectors of human and wildlife exposure. This overview explores three major topics: (i the microbial biogeochemical cycling of Hg in the area, (ii the trophic transfer and bioaccumulation of MeHg in pelagic and benthic marine food webs, and (iii human exposure to Hg through marine fish and shellfish consumption. These are important goals since the Gulf of Trieste is an area of great economical importance.

  2. Investigation of black and brown carbon multiple-wavelength-dependent light absorption from biomass and fossil fuel combustion source emissions

    Science.gov (United States)

    Michael R. Olson; Mercedes Victoria Garcia; Michael A. Robinson; Paul Van Rooy; Mark A. Dietenberger; Michael Bergin; James Jay Schauer

    2015-01-01

    Quantification of the black carbon (BC) and brown carbon (BrC) components of source emissions is critical to understanding the impact combustion aerosols have on atmospheric light absorption. Multiple-wavelength absorption was measured from fuels including wood, agricultural biomass, coals, plant matter, and petroleum distillates in controlled combustion settings....

  3. Sources and Contributions of Oxygen During Microbial Pyrite Oxidation: the Triple Oxygen Isotopes of Sulfate

    Science.gov (United States)

    Ziegler, K.; Coleman, M. L.; Mielke, R. E.; Young, E. D.

    2008-12-01

    The triple isotopes of oxygen (Δ17O' = δ17O'-0.528 × δ18O' using logarithmic deltas) can trace the oxygen sources of sulfate produced during sulfide oxidation, an important biogeochemical process on Earth's surface and possibly also on Mars [1]. δ18OSO4 compositions are determined by the isotopic selectivity of the mechanism(s) responsible for their changes, and the δ18O value of the reactants (O2 vs. H2O). The relative proportional importance and contribution of each of those sources and mechanisms, as well as their associated isotopic fractionations, are not well understood. We are investigating the use of Δ 17O as a quantitative and qualitative tracer for the different processes and oxygen sources involved in sulfate production. Δ17O signatures are distinct fingerprints of these reservoirs, independent of fractionation factors that can be ambiguous. We conducted controlled abiotic and biotic (Acidithiobacillus ferrooxidans, A.f.) laboratory experiments in which water was spiked with 18O, allowing us to quantify the sources of sulfate oxygen and therefore the processes attending sulfate formation. Results of this Δ17O tracer study show that A.f. microbes initiate pyrite S-oxidation within hours of exposure, and that sulfate is produced from ~90% atmospheric oxygen. This initial lag-phase (behavior in the initial lag-phase will aid in the understanding of the ecological conditions required for microbial populations to establish and survive. An exponential phase of growth, facilitated by microbial Fe2+-oxidation, follows. The source of sulfate rapidly switches to abiotic sulfide oxidation during exponential growth and the source of oxygen switches from atmospheric O2 to nearly ~100% water. Pending acquisition of complimentary chemistry data (in progress), we interpret our isotope data to indicate that the biotic fractionation factor ɛ18OSO4-O2 of at least ~ -25 to - 35‰ is augmented by microbially induced kinetic fractionation; it is larger than

  4. Light absorption of biomass burning and vehicle emission-sourced carbonaceous aerosols of the Tibetan Plateau.

    Science.gov (United States)

    Hu, Zhaofu; Kang, Shichang; Li, Chaoliu; Yan, Fangping; Chen, Pengfei; Gao, Shaopeng; Wang, Zhiyong; Zhang, Yulan; Sillanpää, Mika

    2017-06-01

    Carbonaceous aerosols over the Tibetan Plateau originate primarily from biomass burning and vehicle emissions (BB and VEs, respectively). The light absorption characteristics of these carbonaceous aerosols are closely correlated with the burning conditions and represent key factors that influence climate forcing. In this study, the light absorption characteristics of elemental carbon (EC) and water-soluble organic carbon (WSOC) in PM 2.5 (fine particulate matter smaller than 2.5 μm) generated from BB and VEs were investigated over the Tibetan Plateau (TP). The results showed that the organic carbon (OC)/EC ratios from BB- and VE-sourced PM 2.5 were 17.62 ± 10.19 and 1.19 ± 0.36, respectively. These values were higher than the ratios in other regions, which was primarily because of the diminished amount of oxygen over the TP. The mass absorption cross section of EC (MAC EC ) at 632 nm for the BB-sourced PM 2.5 (6.10 ± 1.21 m 2 .g -1 ) was lower than that of the VE-sourced PM 2.5 (8.10 ± 0.98 m 2 .g -1 ), indicating that the EC content of the BB-sourced PM 2.5 was overestimated because of the high OC/EC ratio. The respective absorption per mass (α/ρ) values at 365 nm for the VE- and BB-sourced PM 2.5 were 0.71 ± 0.17 m 2 .g -1 and 0.91 ± 0.18 m 2 .g -1 . The α/ρ value of the VEs was loaded between that of gasoline and diesel emissions, indicating that the VE-sourced PM 2.5 originated from both types of emissions. Because OC and WSOC accounts for most of the carbonaceous aerosols at remote area of the TP, the radiative forcing contributed by the WSOC should be high, and requires further investigation.

  5. Quantifying emissions of NH3 and NOx from Agricultural Sources and Biomass Burning using SOF

    Science.gov (United States)

    Kille, N.; Volkamer, R. M.; Dix, B. K.

    2017-12-01

    Column measurements of trace gas absorption along the direct solar beam present a powerful yet underused approach to quantify emission fluxes from area sources. The University of Colorado Solar Occultation Flux (CU SOF) instrument (Kille et al., 2017, AMT, doi:10.5194/amt-10-373-2017) features a solar tracker that is self-positioning for use from mobile platforms that are in motion (Baidar et al., 2016, AMT, doi: 10.5194/amt-9-963-2016). This enables the use from research aircraft, as well as the deployment under broken cloud conditions, while making efficient use of aircraft time. First airborne SOF measurements have been demonstrated recently, and we discuss applications to study emissions from biomass burning using aircraft, and to study primary emissions of ammonia and nitrogen oxides (= NO + NO2) from area sources such as concentrated animal feeding operations (CAFO). SOF detects gases in the open atmosphere (no inlets), does not require access to the source, and provides results in units that can be directly compared with emission inventories. The method of emission quantification is relatively straightforward. During FRAPPE (Front Range Air Pollution and Photochemistry Experiment) in Colorado in 2014, we measured emission fluxes of NH3, and NOx from CAFO, quantifying the emissions from 61400 of the 535766 cattle in Weld County, CO (11.4% of the cattle population). We find that NH3 emissions from dairy and cattle farms are similar after normalization by the number of cattle, i.e., we find emission factors, EF, of 11.8 ± 2.0 gNH3/h/head for the studied CAFOs; these EFs are at the upper end of reported values. Results are compared to daytime NEI emissions for case study days. Furthermore, biologically active soils are found to be a strong source of NOx. The NOx sources account for 1.2% of the N-flux (i.e., NH3), and can be competitive with other NOx sources in Weld, CO. The added NOx is particularly relevant in remote regions, where O3 formation and oxidative

  6. Origin of fecal contamination in waters from contrasted areas: stanols as Microbial Source Tracking markers.

    Science.gov (United States)

    Derrien, M; Jardé, E; Gruau, G; Pourcher, A M; Gourmelon, M; Jadas-Hécart, A; Pierson Wickmann, A C

    2012-09-01

    Improving the microbiological quality of coastal and river waters relies on the development of reliable markers that are capable of determining sources of fecal pollution. Recently, a principal component analysis (PCA) method based on six stanol compounds (i.e. 5β-cholestan-3β-ol (coprostanol), 5β-cholestan-3α-ol (epicoprostanol), 24-methyl-5α-cholestan-3β-ol (campestanol), 24-ethyl-5α-cholestan-3β-ol (sitostanol), 24-ethyl-5β-cholestan-3β-ol (24-ethylcoprostanol) and 24-ethyl-5β-cholestan-3α-ol (24-ethylepicoprostanol)) was shown to be suitable for distinguishing between porcine and bovine feces. In this study, we tested if this PCA method, using the above six stanols, could be used as a tool in "Microbial Source Tracking (MST)" methods in water from areas of intensive agriculture where diffuse fecal contamination is often marked by the co-existence of human and animal sources. In particular, well-defined and stable clusters were found in PCA score plots clustering samples of "pure" human, bovine and porcine feces along with runoff and diluted waters in which the source of contamination is known. A good consistency was also observed between the source assignments made by the 6-stanol-based PCA method and the microbial markers for river waters contaminated by fecal matter of unknown origin. More generally, the tests conducted in this study argue for the addition of the PCA method based on six stanols in the MST toolbox to help identify fecal contamination sources. The data presented in this study show that this addition would improve the determination of fecal contamination sources when the contamination levels are low to moderate. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Enterococcus and Escherichia coli fecal source apportionment with microbial source tracking genetic markers - is it feasible?

    Science.gov (United States)

    Fecal pollution is measured in surface waters using culture-based measurements of enterococci and Escherichia coli bacteria. Source apportionment of these two fecal indicator bacteria is an urgent need for prioritizing remediation efforts and quantifying health risks associated...

  8. Ambient measurements and source apportionment of fossil fuel and biomass burning black carbon in Ontario

    Science.gov (United States)

    Healy, R. M.; Sofowote, U.; Su, Y.; Debosz, J.; Noble, M.; Jeong, C.-H.; Wang, J. M.; Hilker, N.; Evans, G. J.; Doerksen, G.; Jones, K.; Munoz, A.

    2017-07-01

    Black carbon (BC) is of significant interest from a human exposure perspective but also due to its impacts as a short-lived climate pollutant. In this study, sources of BC influencing air quality in Ontario, Canada were investigated using nine concurrent Aethalometer datasets collected between June 2015 and May 2016. The sampling sites represent a mix of background and near-road locations. An optical model was used to estimate the relative contributions of fossil fuel combustion and biomass burning to ambient concentrations of BC at every site. The highest annual mean BC concentration was observed at a Toronto highway site, where vehicular traffic was found to be the dominant source. Fossil fuel combustion was the dominant contributor to ambient BC at all sites in every season, while the highest seasonal biomass burning mass contribution (35%) was observed in the winter at a background site with minimal traffic contributions. The mass absorption cross-section of BC was also investigated at two sites, where concurrent thermal/optical elemental carbon data were available, and was found to be similar at both locations. These results are expected to be useful for comparing the optical properties of BC at other near-road environments globally. A strong seasonal dependence was observed for fossil fuel BC at every Ontario site, with mean summer mass concentrations higher than their respective mean winter mass concentrations by up to a factor of two. An increased influence from transboundary fossil fuel BC emissions originating in Michigan, Ohio, Pennsylvania and New York was identified for the summer months. The findings reported here indicate that BC should not be considered as an exclusively local pollutant in future air quality policy decisions. The highest seasonal difference was observed at the highway site, however, suggesting that changes in fuel composition may also play an important role in the seasonality of BC mass concentrations in the near-road environment

  9. Performance of two quantitative PCR methods for microbial source tracking of human sewage and implications for microbial risk assessment in recreational waters

    Science.gov (United States)

    Before new, rapid quantitative PCR (qPCR) methods for recreational water quality assessment and microbial source tracking (MST) can be useful in a regulatory context, an understanding of the ability of the method to detect a DNA target (marker) when the contaminant soure has been...

  10. Responses of soil microbial biomass and bacterial community structure to closed-off management (an ecological natural restoration measures): A case study of Dongting Lake wetland, middle China.

    Science.gov (United States)

    Dai, Juan; Wu, Haipeng; Zhang, Chang; Zeng, Guangming; Liang, Jie; Guo, Shenglian; Li, Xiaodong; Huang, Lu; Lu, Lunhui; Yuan, Yujie

    2016-09-01

    Soil microbial biomass (SMB) and bacterial community structure, which are critical to global ecosystem and fundamental ecological processes, are sensitive to anthropogenic activities and environmental conditions. In this study, we examined the possible effects of closed-off management (an ecological natural restoration measures, ban on anthropogenic activity, widely employed for many important wetlands) on SMB, soil bacterial community structure and functional marker genes of nitrogen cycling in Dongting Lake wetland. Soil samples were collected from management area (MA) and contrast area (CA: human activities, such as hunting, fishing and draining, are permitted) in November 2013 and April 2014. Soil properties, microbial biomass carbon (MBC), and bacterial community structure were investigated. Comparison of the values of MA and CA showed that SMB and bacterial community diversity of the MA had a significant increase after 7 years closed-off management. The mean value of Shannon-Weiner diversity index of MA and CA respectively were 2.85 and 2.07. The gene copy numbers of 16S rRNA and nosZ of MA were significant higher than those of CA. the gene copy numbers of ammonia-oxidizing archaea (AOA) and nirK of MA were significant lower than those of CA. However, there was no significant change in the gene copy numbers of ammonia-oxidizing bacteria (AOB) and nirS. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  11. Cultivation of high-biomass crops on coal mine spoil banks: Can microbial inoculation compensate for high doses of organic matter?

    Energy Technology Data Exchange (ETDEWEB)

    Gryndler, M.; Sudova, R.; Puschel, D.; Rydlova, J.; Janouskova, M.; Vosatka, M. [Academy of Science Czech Republic, Pruhonice (Czech Republic)

    2008-09-15

    Two greenhouse experiments were focused on the application of arbuscular mycorrhizal fungi (AMF) and plant growth promoting rhizobacteria (PGPR) in planting of high-biomass crops on reclaimed spoil banks. In the first experiment, we tested the effects of different organic amendments on growth of alfalfa and on the introduced microorganisms. While growth of plants was supported in substrate with compost amendment, mycorrhizal colonization was suppressed. Lignocellulose papermill waste had no negative effects on AMF, but did not positively affect growth of plants. The mixture of these two amendments was found to be optimal in both respects, plant growth and mycorrhizal development. Decreasing doses of this mixture amendment were used in the second experiment, where the effects of microbial inoculation (assumed to compensate for reduced doses of organic matter) on growth of two high-biomass crops, hemp and reed canarygrass, were studied. Plant growth response to microbial inoculation was either positive or negative, depending on the dose of the applied amendment and plant species.

  12. Resolution of habitat-associated ecogenomic signatures in bacteriophage genomes and application to microbial source tracking.

    Science.gov (United States)

    Ogilvie, Lesley A; Nzakizwanayo, Jonathan; Guppy, Fergus M; Dedi, Cinzia; Diston, David; Taylor, Huw; Ebdon, James; Jones, Brian V

    2018-04-01

    Just as the expansion in genome sequencing has revealed and permitted the exploitation of phylogenetic signals embedded in bacterial genomes, the application of metagenomics has begun to provide similar insights at the ecosystem level for microbial communities. However, little is known regarding this aspect of bacteriophage associated with microbial ecosystems, and if phage encode discernible habitat-associated signals diagnostic of underlying microbiomes. Here we demonstrate that individual phage can encode clear habitat-related 'ecogenomic signatures', based on relative representation of phage-encoded gene homologues in metagenomic data sets. Furthermore, we show the ecogenomic signature encoded by the gut-associated ɸB124-14 can be used to segregate metagenomes according to environmental origin, and distinguish 'contaminated' environmental metagenomes (subject to simulated in silico human faecal pollution) from uncontaminated data sets. This indicates phage-encoded ecological signals likely possess sufficient discriminatory power for use in biotechnological applications, such as development of microbial source tracking tools for monitoring water quality.

  13. From vineyard to winery: a source map of microbial diversity driving wine fermentation.

    Science.gov (United States)

    Morrison-Whittle, Peter; Goddard, Matthew R

    2018-01-01

    Humans have been making wine for thousands of years and microorganisms play an integral part in this process as they not only drive fermentation, but also significantly influence the flavour, aroma and quality of finished wines. Since fruits are ephemeral, they cannot comprise a permanent microbial habitat; thus, an age-old unanswered question concerns the origin of fruit and ferment associated microbes. Here we use next-generation sequencing approaches to examine and quantify the roles of native forest, vineyard soil, bark and fruit habitats as sources of fungal diversity in ferments. We show that microbial communities in harvested juice and ferments vary significantly across regions, and that while vineyard fungi account for ∼40% of the source of this diversity, uncultivated ecosystems outside of vineyards also prove a significant source. We also show that while communities in harvested juice resemble those found on grapes, these increasingly resemble fungi present on vine bark as the ferment proceeds. © 2017 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

  14. Impact of land-use and long-term (>150 years) charcoal accumulation on microbial activity, biomass and community structure in temperate soils (Belgium).

    Science.gov (United States)

    Hardy, Brieuc; Cornelis, Jean-Thomas; Dufey, Joseph E.

    2015-04-01

    In the last decade, biochar has been increasingly investigated as a soil amendment for long-term soil carbon sequestration while improving soil fertility. On the short term, biochar application to soil generally increases soil respiration as well as microbial biomass and activity and affects significantly the microbial community structure. However, such effects are relatively short-term and tend to vanish over time. In our study, we investigated the long-term impact of charcoal accumulation and land-use on soil biota in temperate haplic Luvisols developed in the loess belt of Wallonia (Belgium). Charcoal-enriched soils were collected in the topsoil of pre-industrial (>150 years old) charcoal kilns in forest (4 sites) and cropland (5 sites). The topsoil of the adjacent charcoal-unaffected soils was sampled in a comparable way. Soils were characterized (pH, total, organic and inorganic C, total N, exchangeable Ca, Mg, K, Na, cation exchange capacity and available P) and natural soil organic matter (SOM) and black carbon (BC) contents were determined by differential scanning calorimetry. After rewetting at pF 2.5, soils were incubated during 140 days at 20 °C. At 70 days of incubation, 10 g of each soil were freeze dried in order to measure total microbial biomass and community structure by PLFA analysis. The PLFA dataset was analyzed by principal component analysis (PCA) while soil parameters were used as supplementary variables. For both agricultural and forest soils, the respiration rate is highly related to the total microbial biomass (R²=0.90). Both soil respiration and microbial biomass greatly depend on the SOM content, which indicates that the BC pool is relatively inert microbiologically. Land-use explains most of the variance in the PLFA dataset, largely governing the first principal component of the ACP. In forest soils, we observe a larger proportion of gram + bacteria, actinomycetes and an increased bacteria:fungi ratio compared to cropland, where gram

  15. Estimating true human and animal host source contribution in quantitative microbial source tracking using the Monte Carlo method.

    Science.gov (United States)

    Wang, Dan; Silkie, Sarah S; Nelson, Kara L; Wuertz, Stefan

    2010-09-01

    Cultivation- and library-independent, quantitative PCR-based methods have become the method of choice in microbial source tracking. However, these qPCR assays are not 100% specific and sensitive for the target sequence in their respective hosts' genome. The factors that can lead to false positive and false negative information in qPCR results are well defined. It is highly desirable to have a way of removing such false information to estimate the true concentration of host-specific genetic markers and help guide the interpretation of environmental monitoring studies. Here we propose a statistical model based on the Law of Total Probability to predict the true concentration of these markers. The distributions of the probabilities of obtaining false information are estimated from representative fecal samples of known origin. Measurement error is derived from the sample precision error of replicated qPCR reactions. Then, the Monte Carlo method is applied to sample from these distributions of probabilities and measurement error. The set of equations given by the Law of Total Probability allows one to calculate the distribution of true concentrations, from which their expected value, confidence interval and other statistical characteristics can be easily evaluated. The output distributions of predicted true concentrations can then be used as input to watershed-wide total maximum daily load determinations, quantitative microbial risk assessment and other environmental models. This model was validated by both statistical simulations and real world samples. It was able to correct the intrinsic false information associated with qPCR assays and output the distribution of true concentrations of Bacteroidales for each animal host group. Model performance was strongly affected by the precision error. It could perform reliably and precisely when the standard deviation of the precision error was small (≤ 0.1). Further improvement on the precision of sample processing and q

  16. Biomass recalcitrance

    DEFF Research Database (Denmark)

    Felby, Claus

    2009-01-01

    Alternative and renewable fuels derived from lignocellulosic biomass offer a promising alternative to conventional energy sources, and provide energy security, economic growth, and environmental benefits. However, plant cell walls naturally resist decomposition from microbes and enzymes - this co......Alternative and renewable fuels derived from lignocellulosic biomass offer a promising alternative to conventional energy sources, and provide energy security, economic growth, and environmental benefits. However, plant cell walls naturally resist decomposition from microbes and enzymes...... - this collective resistance is known as "biomass recalcitrance." Breakthrough technologies are needed to overcome barriers to developing cost-effective processes for converting biomass to fuels and chemicals. This book examines the connection between biomass structure, ultrastructure, and composition......, to resistance to enzymatic deconstruction, with the aim of discovering new cost-effective technologies for biorefineries. It contains chapters on topics extending from the highest levels of biorefinery design and biomass life-cycle analysis, to detailed aspects of plant cell wall structure, chemical treatments...

  17. Utilization of sup(32)P fixed in iron oxides and aluminium oxides for soil microbial biomass. Utilizacao de sup(32)P fixado em oxidos de ferro e de aluminio pela biomassa microbiana do solo

    Energy Technology Data Exchange (ETDEWEB)

    Maciel Neto, A; Salcedo, I H [Pernambuco Univ., Recife, PE (Brazil). Dept. de Energia Nuclear

    1991-01-01

    The availability of P fixed in oxi-hydroxides of Fe and of Al for the microbial biomass of a P-deficient soil, was determined following addition of C sources. These oxides were impregnated in a support matrix of filter paper strips and then equilibrated with a P solution (1.5 * 1- sup(-5) M) containing sup(32)P. The strips where then incubated with soil without (control) or with additions of glicose+N (70 hs) or celulose+N (3 weeks), and the CO sub(2) evolved measured. After the incubation, the strips with Fe and Al incubated with soil+glicose had 0.004 and 0.008 {mu}moles cm sup(-2) of P less than the controls, respectively. Biomass activity dessorbed 100 to 200 more P than an exchange resin. The Fe strips incubated with soil+celulose dessorbed 0.002 {mu}moles cm sup(-2) more P than the control, while the Al ones did not differ from the control. In this last case, only about 50% of the cellulose had been decomposed, compared to approximately 85% of the cellulose in contact with the Fe strips. (author).

  18. Effect of Arbuscular Mycorrhizal Fungi on Plant Biomass and the Rhizosphere Microbial Community Structure of Mesquite Grown in Acidic Lead/Zinc Mine Tailings

    Science.gov (United States)

    Solís-Domínguez, Fernando A.; Valentín-Vargas, Alexis; Chorover, Jon; Maier, Raina M.

    2011-01-01

    Mine tailings in arid and semi-arid environments are barren of vegetation and subject to eolian dispersion and water erosion. Revegetation is a cost-effective strategy to reduce erosion processes and has wide public acceptance. A major cost of revegetation is the addition of amendments, such as compost, to allow plant establishment. In this paper we explore whether arbuscular mycorrhizal fungi (AMF) can help support plant growth in tailings at a reduced compost concentration. A greenhouse experiment was performed to determine the effects of three AMF inocula on biomass, shoot accumulation of heavy metals, and changes in the rhizosphere microbial community structure of the native plant Prosopis juliflora (mesquite). Plants were grown in an acidic lead/zinc mine tailings amended with 10% (w/w) compost amendment, which is slightly sub-optimal for plant growth in these tailings. After two months, AMF-inoculated plants showed increased dry biomass and root length (p tailings. Mesquite shoot tissue lead and zinc concentrations did not exceed domestic animal toxicity limits regardless of whether AMF inoculation was used. The rhizosphere microbial community structure was assessed using denaturing gradient gel electrophoresis (DGGE) profiles of the small subunit RNA gene for bacteria and fungi. Canonical correspondence analysis (CCA) of DGGE profiles showed that the rhizosphere fungal community structure at the end of the experiment was significantly different from the community structure in the tailings, compost, and AMF inocula prior to planting. Further, CCA showed that AMF inoculation significantly influenced the development of both the fungal and bacterial rhizosphere community structures after two months. The changes observed in the rhizosphere microbial community structure may be either a direct effect of the AMF inocula, caused by changes in plant physiology induced by AMF, or a combination of both mechanisms. PMID:21211826

  19. [Effects of simulated nitrogen deposition on soil microbial biomass carbon and nitrogen in natural evergreen broad-leaved forest in the Rainy Area of West China].

    Science.gov (United States)

    Zhou, Shi Xing; Zou, Cheng; Xiao, Yong Xiang; Xiang, Yuan Bin; Han, Bo Han; Tang, Jian Dong; Luo, Chao; Huang, Cong de

    2017-01-01

    To understand the effects of increasing nitrogen deposition on soil microbial biomass carbon (MBC) and nitrogen(MBN), an in situ experiment was conducted in a natural evergreen broad-leaved forest in Ya'an City, Sichuan Province. Four levels of nitrogen deposition were set: i.e., control (CK, 0 g N·m -2 ·a -1 ), low nitrogen (L, 5 g N·m -2 ·a -1 ), medium nitrogen (M, 15 g N·m -2 ·a -1 ), and high nitrogen (H, 30 g N·m -2 ·a -1 ). The results indicated that nitrogen deposition significantly decreased MBC and MBN in the 0-10 cm soil layer, and as N de-position increased, the inhibition effect was enhanced. L and M treatments had no significant effect on MBC and MBN in the 10-20 cm soil layer, while H treatment significantly reduced. The influence of N deposition on MBC and MBN was weakened with the increase of soil depth. MBC and MBN had obvious seasonal dynamic, which were highest in autumn and lowest in summer both in the 0-10 and 10-20 cm soil layers. The fluctuation ranges of soil microbial biomass C/N were respectively 10.58-11.19 and 9.62-12.20 in the 0-10 cm and 10-20 cm soil layers, which indicated that the fungi hold advantage in the soil microbial community in this natural evergreen broad-leaved forest.

  20. Effect of arbuscular mycorrhizal fungi on plant biomass and the rhizosphere microbial community structure of mesquite grown in acidic lead/zinc mine tailings.

    Science.gov (United States)

    Solís-Domínguez, Fernando A; Valentín-Vargas, Alexis; Chorover, Jon; Maier, Raina M

    2011-02-15

    Mine tailings in arid and semi-arid environments are barren of vegetation and subject to eolian dispersion and water erosion. Revegetation is a cost-effective strategy to reduce erosion processes and has wide public acceptance. A major cost of revegetation is the addition of amendments, such as compost, to allow plant establishment. In this paper we explore whether arbuscular mycorrhizal fungi (AMF) can help support plant growth in tailings at a reduced compost concentration. A greenhouse experiment was performed to determine the effects of three AMF inocula on biomass, shoot accumulation of heavy metals, and changes in the rhizosphere microbial community structure of the native plant Prosopis juliflora (mesquite). Plants were grown in an acidic lead/zinc mine tailings amended with 10% (w/w) compost amendment, which is slightly sub-optimal for plant growth in these tailings. After two months, AMF-inoculated plants showed increased dry biomass and root length (p<0.05) and effective AMF colonization compared to controls grown in uninoculated compost-amended tailings. Mesquite shoot tissue lead and zinc concentrations did not exceed domestic animal toxicity limits regardless of whether AMF inoculation was used. The rhizosphere microbial community structure was assessed using denaturing gradient gel electrophoresis (DGGE) profiles of the small subunit RNA gene for bacteria and fungi. Canonical correspondence analysis (CCA) of DGGE profiles showed that the rhizosphere fungal community structure at the end of the experiment was significantly different from the community structure in the tailings, compost, and AMF inocula prior to planting. Further, CCA showed that AMF inoculation significantly influenced the development of both the fungal and bacterial rhizosphere community structures after two months. The changes observed in the rhizosphere microbial community structure may be either a direct effect of the AMF inocula, caused by changes in plant physiology induced by

  1. Soil microbial biomass under pine forests in the north-western Spain: influence of stand age, site index and parent material

    Energy Technology Data Exchange (ETDEWEB)

    Mahia, J.; Perez-Ventura, L.; Cabaneiro, A.; Diaz-Ravina, M.

    2006-07-01

    The effects of stand age, site index and parent material on soil biochemical properties related to biomass (extractable C, microbial C and metabolic quotient) were examined in the 0-15 cm mineral soil layers of Pinus pinaster and Pinus sylvestris stand from NW Spain. Two productivity levels (low and high site index), two ages (young and old) and two parent soil materials (granite and acid schists) were considered. The data indicated that there were differences in microbial parameters in soils under different species. In general in P. pinaster forest higher values of biochemical parameters expressed on organic C basis, were observed in the stands of high site index as compared with the low ones; in contrast, in P. sylvestris no differences among stand site index were detected. In both species different results were also observed depending on parent material and a significant effect of stand age was detected for extractable C and microbial C in P. pinaster forest developed over granite. The data seem to indicate that measured parameters may have the potential to be used as indicators of the effect of forest management on soil organic matter quality. (Author) 25 refs.

  2. Good Manufacturing Practices and Microbial Contamination Sources in Orange Fleshed Sweet Potato Puree Processing Plant in Kenya

    Directory of Open Access Journals (Sweden)

    Derick Nyabera Malavi

    2018-01-01

    Full Text Available Limited information exists on the status of hygiene and probable sources of microbial contamination in Orange Fleshed Sweet Potato (OFSP puree processing. The current study is aimed at determining the level of compliance to Good Manufacturing Practices (GMPs, hygiene, and microbial quality in OFSP puree processing plant in Kenya. Intensive observation and interviews using a structured GMPs checklist, environmental sampling, and microbial analysis by standard microbiological methods were used in data collection. The results indicated low level of compliance to GMPs with an overall compliance score of 58%. Microbial counts on food equipment surfaces, installations, and personnel hands and in packaged OFSP puree were above the recommended microbial safety and quality legal limits. Steaming significantly (P<0.05 reduced microbial load in OFSP cooked roots but the counts significantly (P<0.05 increased in the puree due to postprocessing contamination. Total counts, yeasts and molds, Enterobacteriaceae, total coliforms, and E. coli and S. aureus counts in OFSP puree were 8.0, 4.0, 6.6, 5.8, 4.8, and 5.9 log10 cfu/g, respectively. In conclusion, equipment surfaces, personnel hands, and processing water were major sources of contamination in OFSP puree processing and handling. Plant hygiene inspection, environmental monitoring, and food safety trainings are recommended to improve hygiene, microbial quality, and safety of OFSP puree.

  3. Multi-year microbial source tracking study characterizing fecal contamination in an urban watershed

    Science.gov (United States)

    Bushon, Rebecca N.; Brady, Amie M. G.; Christensen, Eric D.; Stelzer, Erin A.

    2017-01-01

    Microbiological and hydrological data were used to rank tributary stream contributions of bacteria to the Little Blue River in Independence, Missouri. Concentrations, loadings and yields of E. coli and microbial source tracking (MST) markers, were characterized during base flow and storm events in five subbasins within Independence, as well as sources entering and leaving the city through the river. The E. coli water quality threshold was exceeded in 29% of base-flow and 89% of storm-event samples. The total contribution of E. coli and MST markers from tributaries within Independence to the Little Blue River, regardless of streamflow, did not significantly increase the median concentrations leaving the city. Daily loads and yields of E. coli and MST markers were used to rank the subbasins according to their contribution of each constituent to the river. The ranking methodology used in this study may prove useful in prioritizing remediation in the different subbasins.

  4. Growth of oleaginous Rhodotorula glutinis in an internal-loop airlift bioreactor by using lignocellulosic biomass hydrolysate as the carbon source.

    Science.gov (United States)

    Yen, Hong-Wei; Chang, Jung-Tzu

    2015-05-01

    The conversion of abundant lignocellulosic biomass (LCB) to valuable compounds has become a very attractive idea recently. This study successfully used LCB (rice straw) hydrolysate as a carbon source for the cultivation of oleaginous yeast-Rhodotorula glutinis in an airlift bioreactor. The lipid content of 34.3 ± 0.6% was obtained in an airlift batch with 60 g reducing sugars/L of LCB hydrolysate at a 2 vvm aeration rate. While using LCB hydrolysate as the carbon source, oleic acid (C18:1) and linoleic acid (C18:2) were the predominant fatty acids of the microbial lipids. Using LCB hydrolysate in the airlift bioreactor at 2 vvm achieved the highest cell mass growth as compared to the agitation tank. Despite the low lipid content of the batch using LCB hydrolysate, this low cost feedstock has the potential of being adopted for the production of β-carotene instead of lipid accumulation in the airlift bioreactor for the cultivation of R. glutinis. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  5. Differential Decay of Cattle-associated Fecal Indicator Bacteria and Microbial Source Tracking Markers in Fresh and Marine Water

    Science.gov (United States)

    Background: Fecal indicator bacteria (FIB) have a long history of use in the assessment of the microbial quality of recreational waters. However, quantification of FIB provides no information about the pollution source(s) and relatively little is known about their fate in the amb...

  6. Effects of Calcium Source on Biochemical Properties of Microbial CaCO3 Precipitation.

    Science.gov (United States)

    Xu, Jing; Du, Yali; Jiang, Zhengwu; She, Anming

    2015-01-01

    The biochemical properties of CaCO3 precipitation induced by Sporosarcina pasteurii, an ureolytic type microorganism, were investigated. Effects of calcium source on the precipitation process were examined, since calcium source plays a key role in microbiologically induced mineralization. Regardless of the calcium source type, three distinct stages in the precipitation process were identified by Ca(2+), NH4 (+), pH and cell density monitoring. Compared with stage 1 and 3, stage 2 was considered as the most critical part since biotic CaCO3 precipitation occurs during this stage. Kinetics studies showed that the microbial CaCO3 precipitation rate for calcium lactate was over twice of that for calcium nitrate, indicating that calcium lactate is more beneficial for the cell activity, which in turn determines urease production and CaCO3 precipitation. X-ray diffraction analysis confirmed the CaCO3 crystal as calcite, although scanning electron microscopy revealed a difference in crystal size and morphology if calcium source was different. The findings of this paper further suggest a promising application of microbiologically induced CaCO3 precipitation in remediation of surface and cracks of porous media, e.g., cement-based composites, particularly by using organic source of calcium lactate.

  7. Panus tigrinus as a potential biomass source for Reactive Blue decolorization: Isotherm and kinetic study

    Directory of Open Access Journals (Sweden)

    Monawar Munjid Mustafa

    2017-03-01

    Conclusion: The biosorption process provided vital information on the process parameters required to obtain the optimum level of dye removal. The isotherm study indicated the homogeneous distribution of active sites on the biomass surface, and the kinetic study suggested that chemisorption is the rate-limiting step that controlled the biosorption process. According to the obtained results, P. tigrinus biomass can be used effectively to decolorize textile dyes and tackle the pollution problems in the environment.

  8. Growth of filamentous blue-green algae at high temperatures: a source of biomass for renewable fuels

    Energy Technology Data Exchange (ETDEWEB)

    Timourian, H.; Ward, R.L.; Jeffries, T.W.

    1977-08-17

    The growth of filamentous blue-green algae (FBGA) at high temperatures in outdoor, shallow solar ponds is being investigated. The temperature of the 60-m/sup 2/ ponds can be controlled to an average temperature of 45/sup 0/C. The growth of FBGA at high temperatures offers an opportunity, not presently available from outdoor algal ponds or energy farms, to obtain large amounts of biomass. Growth of algae at high temperatures results in higher yields because of increased growth rate, the higher light intensity that can be used before saturating the photosynthetic process, easier maintenance of selected FBGA strains, and fewer predators to decimate culture. Additional advantages of growing FBGA as a source of biomass include: bypassing the limitations of nutrient sources, because FBGA fix their own nitrogen and require only CO/sub 2/ when inorganic nutrients are recycled; toleration of higher salinity and metal ion concentrations; and easier and less expensive harvesting procedures.

  9. Comparison of in vitro toxicological effects of biomass smoke from different sources of animal dung.

    Science.gov (United States)

    McCarthy, Claire E; Duffney, Parker F; Wyatt, Jeffrey D; Thatcher, Thomas H; Phipps, Richard P; Sime, Patricia J

    2017-09-01

    Worldwide, over 4 million premature deaths each year are attributed to the burning of biomass fuels for cooking and heating. Epidemiological studies associate household air pollution with lung diseases, including chronic obstructive pulmonary disease, lung cancer, and respiratory infections. Animal dung, a biomass fuel used by economically vulnerable populations, generates more toxic compounds per mass burned than other biomass fuels. The type of animal dung used varies widely depending on local agro-geography. There are currently neither standardized experimental systems for dung biomass smoke research nor studies assessing the health impacts of different types of dung smoke. Here, we used a novel reproducible exposure system to assess outcomes related to inflammation and respiratory infections in human airway cells exposed to six different types of dung biomass smoke. We report that dung biomass smoke, regardless of species, is pro-inflammatory and activates the aryl hydrocarbon receptor and JNK transcription factors; however, dung smoke also suppresses interferon responses after a challenge with a viral mimetic. These effects are consistent with epidemiological data, and suggest a mechanism by which the combustion of animal dung can directly cause lung diseases, promote increased susceptibility to infection, and contribute to the global health problem of household air pollution. Copyright © 2017. Published by Elsevier Ltd.

  10. Algal Biomass from Wastewater and Flue Gases as a Source of Bioenergy

    Directory of Open Access Journals (Sweden)

    Sandra Lage

    2018-03-01

    Full Text Available Algae are without doubt the most productive photosynthetic organisms on Earth; they are highly efficient in converting CO2 and nutrients into biomass. These abilities can be exploited by culturing microalgae from wastewater and flue gases for effective wastewater reclamation. Algae are known to remove nitrogen and phosphorus as well as several organic contaminants including pharmaceuticals from wastewater. Biomass production can even be enhanced by the addition of CO2 originating from flue gases. The algal biomass can then be used as a raw material to produce bioenergy; depending on its composition, various types of biofuels such as biodiesel, biogas, bioethanol, biobutanol or biohydrogen can be obtained. However, algal biomass generated in wastewater and flue gases also contains contaminants which, if not degraded, will end up in the ashes. In this review, the current knowledge on algal biomass production in wastewater and flue gases is summarized; special focus is given to the algal capacity to remove contaminants from wastewater and flue gases, and the consequences when converting this biomass into different types of biofuels.

  11. Characterization of biomass burning from olive grove areas: A major source of organic aerosol in PM10 of Southwest Europe

    Science.gov (United States)

    Sánchez de la Campa, Ana M.; Salvador, Pedro; Fernández-Camacho, Rocío; Artiñano, Begoña; Coz, Esther; Márquez, Gonzalo; Sánchez-Rodas, Daniel; de la Rosa, Jesús

    2018-01-01

    The inorganic and organic geochemistry of aerosol particulate matter (APM) was studied in a major olive grove area from Southwest Europe (Baena, Spain). The biomass consists of olive tree branches and the solid waste resulting of the olive oil production. Moreover, high PM10 levels were obtained (31.5 μg m- 3), with two days of exceedance of the daily limit of 50 μg m- 3 (2008/50/CE; EU, 2008) during the experimental period. A high mean levoglucosan concentration was obtained representing up 95% of the total mass of the isomers analysed (280 ng m- 3), while galactosan and mannosan mean concentrations were lower (8.64 ng m- 3 and 7.86 ng m- 3, respectively). The contribution of wood smoke in Baena was estimated, representing 19% of OC and 17% of OM total mass. Positive matrix factor (PMF) was applied to the organic and inorganic aerosols data, which has permitted the identification of five source categories: biomass burning, traffic, mineral dust, marine aerosol and SIC (secondary inorganic compounds). The biomass burning category reached the highest mean contribution to the PM10 mass (41%, 17.6 μg m- 3). In light of these results, the use of biomass resulting from the olive oil production for residential heating and industry must be considered the most important aerosol source during the winter months. The results of this paper can be extrapolated to other olive oil producing areas in the Mediterranean basin. Therefore, a fuller understanding of this type of biomass combustion is required in order to be able to establish appropriate polices and reduce the environmental impact on the population.

  12. Rapid biological oxidation of methanol in the tropical Atlantic: significance as a microbial carbon source

    Directory of Open Access Journals (Sweden)

    J. L. Dixon

    2011-09-01

    Full Text Available Methanol is the second most abundant organic gas in the atmosphere after methane, and is ubiquitous in the troposphere. It plays a significant role in atmospheric oxidant chemistry and is biogeochemically active. Large uncertainties exist about whether the oceans are a source or sink of methanol to the atmosphere. Even less is understood about what reactions in seawater determine its concentration, and hence flux across the sea surface interface. We report here concentrations of methanol between 151–296 nM in parts of the oligotrophic North Atlantic, with corresponding microbial uptake rates between 2–146 nM d−1, suggesting turnover times as low as 1 day (1–25 days in surface waters of the oligotrophic tropical North East Atlantic. Methanol is mainly (≥97% used by microbes for obtaining energy in oligotrophic regions, which contrasts with shelf and coastal areas where between 20–50% can be used for cell growth. Comparisons of microbial methanol oxidation rates with parallel determinations of bacterial leucine uptake suggest that methanol contributes on average 13% to bacterial carbon demand in the central northern Atlantic gyre (maximum of 54%. In addition, the contribution that methanol makes to bacterial carbon demand varies as a power function of chlorophyll a concentrations; suggesting for concentrations <0.2 μg l−1 that methanol can make a significant contribution to bacterial carbon demand. However, our low air to sea methanol flux estimates of 7.2–13 μmol m−2 d−1 suggest that the atmosphere is not a major methanol source. We conclude that there must be a major, as yet unidentified, in situ oceanic methanol source in these latitudes which we suggest is sunlight driven decomposition of organic matter.

  13. Thermoascus aurantiacus is a promising source of enzymes for biomass deconstruction under thermophilic conditions

    Directory of Open Access Journals (Sweden)

    McClendon Shara D

    2012-07-01

    Full Text Available Abstract Background Thermophilic fungi have attracted increased interest for their ability to secrete enzymes that deconstruct biomass at high temperatures. However, development of thermophilic fungi as enzyme producers for biomass deconstruction has not been thoroughly investigated. Comparing the enzymatic activities of thermophilic fungal strains that grow on targeted biomass feedstocks has the potential to identify promising candidates for strain development. Thielavia terrestris and Thermoascus aurantiacus were chosen for characterization based on literature precedents. Results Thermoascus aurantiacus and Thielavia terrestris were cultivated on various biomass substrates and culture supernatants assayed for glycoside hydrolase activities. Supernatants from both cultures possessed comparable glycoside hydrolase activities when incubated with artificial biomass substrates. In contrast, saccharifications of ionic liquid pretreated switchgrass (Panicum virgatum revealed that T. aurantiacus enzymes released more glucose than T. terrestris enzymes over a range of protein mass loadings and temperatures. Temperature-dependent saccharifications demonstrated that the T. aurantiacus proteins retained higher levels of activity compared to a commercial enzyme mixture sold by Novozymes, Cellic CTec2, at elevated temperatures. Enzymes secreted by T. aurantiacus released glucose at similar protein loadings to CTec2 on dilute acid, ammonia fiber expansion, or ionic liquid pretreated switchgrass. Proteomic analysis of the T. aurantiacus culture supernatant revealed dominant glycoside hydrolases from families 5, 7, 10, and 61, proteins that are key enzymes in commercial cocktails. Conclusions T. aurantiacus produces a complement of secreted proteins capable of higher levels of saccharification of pretreated switchgrass than T. terrestris enzymes. The T. aurantiacus enzymatic cocktail performs at the same level as commercially available enzymatic cocktail for

  14. Thermoascus aurantiacus is a promising source of enzymes for biomass deconstruction under thermophilic conditions.

    Science.gov (United States)

    McClendon, Shara D; Batth, Tanveer; Petzold, Christopher J; Adams, Paul D; Simmons, Blake A; Singer, Steven W

    2012-07-28

    Thermophilic fungi have attracted increased interest for their ability to secrete enzymes that deconstruct biomass at high temperatures. However, development of thermophilic fungi as enzyme producers for biomass deconstruction has not been thoroughly investigated. Comparing the enzymatic activities of thermophilic fungal strains that grow on targeted biomass feedstocks has the potential to identify promising candidates for strain development. Thielavia terrestris and Thermoascus aurantiacus were chosen for characterization based on literature precedents. Thermoascus aurantiacus and Thielavia terrestris were cultivated on various biomass substrates and culture supernatants assayed for glycoside hydrolase activities. Supernatants from both cultures possessed comparable glycoside hydrolase activities when incubated with artificial biomass substrates. In contrast, saccharifications of ionic liquid pretreated switchgrass (Panicum virgatum) revealed that T. aurantiacus enzymes released more glucose than T. terrestris enzymes over a range of protein mass loadings and temperatures. Temperature-dependent saccharifications demonstrated that the T. aurantiacus proteins retained higher levels of activity compared to a commercial enzyme mixture sold by Novozymes, Cellic CTec2, at elevated temperatures. Enzymes secreted by T. aurantiacus released glucose at similar protein loadings to CTec2 on dilute acid, ammonia fiber expansion, or ionic liquid pretreated switchgrass. Proteomic analysis of the T. aurantiacus culture supernatant revealed dominant glycoside hydrolases from families 5, 7, 10, and 61, proteins that are key enzymes in commercial cocktails. T. aurantiacus produces a complement of secreted proteins capable of higher levels of saccharification of pretreated switchgrass than T. terrestris enzymes. The T. aurantiacus enzymatic cocktail performs at the same level as commercially available enzymatic cocktail for biomass deconstruction, without strain development or

  15. Assessment of statistical methods used in library-based approaches to microbial source tracking.

    Science.gov (United States)

    Ritter, Kerry J; Carruthers, Ethan; Carson, C Andrew; Ellender, R D; Harwood, Valerie J; Kingsley, Kyle; Nakatsu, Cindy; Sadowsky, Michael; Shear, Brian; West, Brian; Whitlock, John E; Wiggins, Bruce A; Wilbur, Jayson D

    2003-12-01

    Several commonly used statistical methods for fingerprint identification in microbial source tracking (MST) were examined to assess the effectiveness of pattern-matching algorithms to correctly identify sources. Although numerous statistical methods have been employed for source identification, no widespread consensus exists as to which is most appropriate. A large-scale comparison of several MST methods, using identical fecal sources, presented a unique opportunity to assess the utility of several popular statistical methods. These included discriminant analysis, nearest neighbour analysis, maximum similarity and average similarity, along with several measures of distance or similarity. Threshold criteria for excluding uncertain or poorly matched isolates from final analysis were also examined for their ability to reduce false positives and increase prediction success. Six independent libraries used in the study were constructed from indicator bacteria isolated from fecal materials of humans, seagulls, cows and dogs. Three of these libraries were constructed using the rep-PCR technique and three relied on antibiotic resistance analysis (ARA). Five of the libraries were constructed using Escherichia coli and one using Enterococcus spp. (ARA). Overall, the outcome of this study suggests a high degree of variability across statistical methods. Despite large differences in correct classification rates among the statistical methods, no single statistical approach emerged as superior. Thresholds failed to consistently increase rates of correct classification and improvement was often associated with substantial effective sample size reduction. Recommendations are provided to aid in selecting appropriate analyses for these types of data.

  16. Good Manufacturing Practices and Microbial Contamination Sources in Orange Fleshed Sweet Potato Puree Processing Plant in Kenya

    Science.gov (United States)

    Abong', George Ooko

    2018-01-01

    Limited information exists on the status of hygiene and probable sources of microbial contamination in Orange Fleshed Sweet Potato (OFSP) puree processing. The current study is aimed at determining the level of compliance to Good Manufacturing Practices (GMPs), hygiene, and microbial quality in OFSP puree processing plant in Kenya. Intensive observation and interviews using a structured GMPs checklist, environmental sampling, and microbial analysis by standard microbiological methods were used in data collection. The results indicated low level of compliance to GMPs with an overall compliance score of 58%. Microbial counts on food equipment surfaces, installations, and personnel hands and in packaged OFSP puree were above the recommended microbial safety and quality legal limits. Steaming significantly (P contamination. Total counts, yeasts and molds, Enterobacteriaceae, total coliforms, and E. coli and S. aureus counts in OFSP puree were 8.0, 4.0, 6.6, 5.8, 4.8, and 5.9 log10 cfu/g, respectively. In conclusion, equipment surfaces, personnel hands, and processing water were major sources of contamination in OFSP puree processing and handling. Plant hygiene inspection, environmental monitoring, and food safety trainings are recommended to improve hygiene, microbial quality, and safety of OFSP puree. PMID:29808161

  17. Good Manufacturing Practices and Microbial Contamination Sources in Orange Fleshed Sweet Potato Puree Processing Plant in Kenya.

    Science.gov (United States)

    Malavi, Derick Nyabera; Muzhingi, Tawanda; Abong', George Ooko

    2018-01-01

    Limited information exists on the status of hygiene and probable sources of microbial contamination in Orange Fleshed Sweet Potato (OFSP) puree processing. The current study is aimed at determining the level of compliance to Good Manufacturing Practices (GMPs), hygiene, and microbial quality in OFSP puree processing plant in Kenya. Intensive observation and interviews using a structured GMPs checklist, environmental sampling, and microbial analysis by standard microbiological methods were used in data collection. The results indicated low level of compliance to GMPs with an overall compliance score of 58%. Microbial counts on food equipment surfaces, installations, and personnel hands and in packaged OFSP puree were above the recommended microbial safety and quality legal limits. Steaming significantly ( P contamination. Total counts, yeasts and molds, Enterobacteriaceae, total coliforms, and E. coli and S. aureus counts in OFSP puree were 8.0, 4.0, 6.6, 5.8, 4.8, and 5.9 log 10 cfu/g, respectively. In conclusion, equipment surfaces, personnel hands, and processing water were major sources of contamination in OFSP puree processing and handling. Plant hygiene inspection, environmental monitoring, and food safety trainings are recommended to improve hygiene, microbial quality, and safety of OFSP puree.

  18. Fractionation of phosphorus added as a vegetal residue (32 P) and a fertilizer (32 P) between soil, plant and microbial biomass

    International Nuclear Information System (INIS)

    Pereira, M.C.

    1988-04-01

    Sugar cane straw and/or P-fertilizer phosphorus-32 labelled were added to a Red Yellow podzolic soil from Goiana-PE. The treated samples were used in a pot experiment, growing sorghum plants for 4 and 6 weeks, and in an incubation experiment with incubation periods of 1, 2, 3, 4 and 6 weeks without plants in order to follow the dynamics of the P added. After each harvest and incubation period the soil were analysed for 31 P and 32 P in the microbial biomass and in sequential extracts with resin (Pi), 0.5 M Na H Co 3 (Pi, Po) and 0.1 N NaOH (Pi, Po). The 31 P and 32 P contents of the sorghum in the pot experiment were also determined. (author)

  19. Urease activity and its relation to soil organic matter, microbial biomass nitrogen and urea-nitrogen assimilation by maize in a Brazilian oxisol under no-tillage and tillage systems

    NARCIS (Netherlands)

    Roscoe, R.; Vasconcellos, C.A.; Furtini Neto, A.E.; Guedes, G.A.A.; Fernandes, L.A.

    2000-01-01

    We studied the relationship between urease activity (UA) and soil organic matter (SOM), microbial biomass N (Nbiom) content, and urea-N fertilizer assimilation by maize in a Dark Red Latosol (Typic Haplustox) cultivated for 9 years under no-tillage (NT), tillage with a disc plough (DP), and tillage

  20. Effect of incorporation of walnut cake (Juglans regia in concentrate mixture on degradation of dry matter, organic matter and production of microbial biomass in vitro in goat

    Directory of Open Access Journals (Sweden)

    Mohsin Ahmad Mir

    2015-10-01

    Full Text Available Aim: This study was carried out to investigate the effect of incorporation of different level of walnut cake in concentrate mixture on in vitro dry matter degradation in order to determine its level of supplementation in ruminant ration. Materials and Methods: Walnut cake was used @ 0, 10, 15, 20, 25 and 30% level to formulate an iso-nitrogenous concentrate mixtures and designated as T1, T2, T3, T4, T5 and T6 respectively. The different formulae of concentrate mixtures were used for in vitro gas production studies using goat rumen liquor with wheat straw in 40:60 ratio. Proximate composition, fiber fractionation and calcium and phosphrous content of walnut cake were estimated. Result: The per cent IVDMD value of T1 and T2 diets was 68.42 ± 1.20 and 67.25 ± 1.37 respectively which was found highest (P<0.05 T3, T4, T5 and T6. Similar trend was also found for TDOM and MBP. Inclusion of walnut cake at 10% level in the concentrate mixture does not affect in vitro dry matter digestibility (IVDMD, truly degradable organic matter (TDOM, mg/200 mg DM, total gas production, microbial biomass production (MBP and efficiency of microbial biomass production (EMP. Conclusion: It is concluded that walnut cake incorporation up to 10% level in the iso -nitrogenous concentrate mixture has no any negative effect on in vitro digestibility of dry matter (DM, TDOM, MBP, EMP and total gas production in goat.

  1. Evaluation of optimum roughage to concentrate ratio in maize stover based complete rations for efficient microbial biomass production using in vitro gas production technique

    Directory of Open Access Journals (Sweden)

    Y. Ramana Reddy

    2016-06-01

    Full Text Available Aim: A study was undertaken to evaluate the optimum roughage to concentrate ratio in maize stover (MS based complete diets for efficient microbial biomass production (EMBP using in vitro gas production technique. Materials and Methods: MS based complete diets with roughage to concentrate ratio of 100:0, 90:10, 80:20, 70:30, 60:40, 50:50, 40:60, and 30:70 were formulated, and 200 mg of oven-dried sample was incubated in water bath at 39°C along with media (rumen liquor [RL] - buffer in in vitro gas syringes to evaluate the gas production. The gas produced was recorded at 8 and 24 h of inc ubation. In vitro organic matter digestibility (IVOMD, metabolizable energy (ME, truly digestible organic matter (TDOM, partitioning factor (PF, and EMBP were calculated using appropriate formulae. Ammonia nitrogen and total volatile fatty acids (TVFAs production were analyzed in RL fluid-media mixture after 24 h of incubation. Results: In vitro gas production (ml at 24 h incubation, IVOMD, ME, TDOM, TVFA concentration, and ammonia nitrogen production were increased (p<0.01 in proportion to the increase in the level of concentrate in the diet. Significantly (p<0.01 higher PF and EMBP was noticed in total mixed ration with roughage to concentrate ratio of 60:40 and 50:50 followed by 70:30 and 40:60. Conclusion: Based on the results, it was concluded that the MS can be included in complete rations for ruminants at the level of 50-60% for better microbial biomass synthesis which in turn influences the performance of growing sheep.

  2. Evaluation of optimum roughage to concentrate ratio in maize stover based complete rations for efficient microbial biomass production using in vitro gas production technique.

    Science.gov (United States)

    Reddy, Y Ramana; Kumari, N Nalini; Monika, T; Sridhar, K

    2016-06-01

    A study was undertaken to evaluate the optimum roughage to concentrate ratio in maize stover (MS) based complete diets for efficient microbial biomass production (EMBP) using in vitro gas production technique. MS based complete diets with roughage to concentrate ratio of 100:0, 90:10, 80:20, 70:30, 60:40, 50:50, 40:60, and 30:70 were formulated, and 200 mg of oven-dried sample was incubated in water bath at 39°C along with media (rumen liquor [RL] - buffer) in in vitro gas syringes to evaluate the gas production. The gas produced was recorded at 8 and 24 h of incubation. In vitro organic matter digestibility (IVOMD), metabolizable energy (ME), truly digestible organic matter (TDOM), partitioning factor (PF), and EMBP were calculated using appropriate formulae. Ammonia nitrogen and total volatile fatty acids (TVFAs) production were analyzed in RL fluid-media mixture after 24 h of incubation. In vitro gas production (ml) at 24 h incubation, IVOMD, ME, TDOM, TVFA concentration, and ammonia nitrogen production were increased (p<0.01) in proportion to the increase in the level of concentrate in the diet. Significantly (p<0.01) higher PF and EMBP was noticed in total mixed ration with roughage to concentrate ratio of 60:40 and 50:50 followed by 70:30 and 40:60. Based on the results, it was concluded that the MS can be included in complete rations for ruminants at the level of 50-60% for better microbial biomass synthesis which in turn influences the performance of growing sheep.

  3. Investigations on microbial leaching of zircon by means of spark source mass spectrometry

    International Nuclear Information System (INIS)

    Becker, S.; Dietze, H.J.; Bullmann, M.; Iske, U.

    1985-01-01

    Spark source mass spectrometry is a useful method for chemical element analysis of geological and biological samples. This sensitive technique (detection limit down to the ppb-range) is used to analyze leaching processes by means of several microorganisms. The problem of microbial leaching of chemical resistent materials was tested under laboratory condition with regard to possible analytical and technical applications. Leaching of metalls with chemolithotrophic and heterotrophic, organic acids producing microorganisms has been investigated with zircon from Baltic Shield containing 0.7% rare earth elements and 1.67% hafnium. When zircon is leached with strains of Thiobacillus ferroxidans the rare earth elements, Hf, Th, and U mostly (about 80%) can be recovered. (author)

  4. Microbial characterization for the Source-Term Waste Test Program (STTP) at Los Alamos

    International Nuclear Information System (INIS)

    Leonard, P.A.; Strietelmeier, B.A.; Pansoy-Hjelvik, M.E.; Villarreal, R.

    1999-01-01

    The effects of microbial activity on the performance of the proposed underground nuclear waste repository, the Waste Isolation Pilot Plant (WIPP) at Carlsbad, New Mexico are being studied at Los Alamos National Laboratory (LANL) as part of an ex situ large-scale experiment. Actual actinide-containing waste is being used to predict the effect of potential brine inundation in the repository in the distant future. The study conditions are meant to simulate what might exist should the underground repository be flooded hundreds of years after closure as a result of inadvertent drilling into brine pockets below the repository. The Department of Energy (DOE) selected LANL to conduct the Actinide Source-Term Waste Test Program (STTP) to confirm the predictive capability of computer models being developed at Sandia National Laboratory

  5. A Predictive Model for Microbial Counts on Beaches where Intertidal Sand is the Primary Source

    Science.gov (United States)

    Feng, Zhixuan; Reniers, Ad; Haus, Brian K.; Solo-Gabriele, Helena M.; Wang, John D.; Fleming, Lora E.

    2015-01-01

    Human health protection at recreational beaches requires accurate and timely information on microbiological conditions to issue advisories. The objective of this study was to develop a new numerical mass balance model for enterococci levels on nonpoint source beaches. The significant advantage of this model is its easy implementation, and it provides a detailed description of the cross-shore distribution of enterococci that is useful for beach management purposes. The performance of the balance model was evaluated by comparing predicted exceedances of a beach advisory threshold value to field data, and to a traditional regression model. Both the balance model and regression equation predicted approximately 70% the advisories correctly at the knee depth and over 90% at the waist depth. The balance model has the advantage over the regression equation in its ability to simulate spatiotemporal variations of microbial levels, and it is recommended for making more informed management decisions. PMID:25840869

  6. Inferring energy sources in constructed wetlands through stable isotope analysis of microbial biofilms

    Energy Technology Data Exchange (ETDEWEB)

    Jurkowski, K.; Ciborowski, J. [Windsor Univ., ON (Canada); Daly, C. [Suncor Energy, Fort McMurray, AB (Canada)

    2010-07-01

    This study presented a novel method of sequestering the microbial biofilm in constructed wetland ecosystems. Artificial substrates were fixed within 8 wetlands differing in age and construction materials over a 2 year period at oil sands lease sites in northeastern Alberta. Autotrophic and heterotrophic biofilm samples were collected from both the subsurface and epibenthic zones of the pipe surfaces of each submerged substrate assembly. A mixing model of d13C, d15N and d34S isotopic signatures was used to assess the contribution of 4 potential nutrient sources of the biofilm. Samples included dominant living and senescent emergent as well as submergent macrophytes, particulate organic matter, dissolved organic carbon, and invertebrates. The samples were collected to compare the biofilm signatures of each wetland in relation to the heterotrophic processes caused by the assimilation of oil sands-derived hydrocarbons and autochthonous detrital pools.

  7. Inferring energy sources in constructed wetlands through stable isotope analysis of microbial biofilms

    International Nuclear Information System (INIS)

    Jurkowski, K.; Ciborowski, J.; Daly, C.

    2010-01-01

    This study presented a novel method of sequestering the microbial biofilm in constructed wetland ecosystems. Artificial substrates were fixed within 8 wetlands differing in age and construction materials over a 2 year period at oil sands lease sites in northeastern Alberta. Autotrophic and heterotrophic biofilm samples were collected from both the subsurface and epibenthic zones of the pipe surfaces of each submerged substrate assembly. A mixing model of d13C, d15N and d34S isotopic signatures was used to assess the contribution of 4 potential nutrient sources of the biofilm. Samples included dominant living and senescent emergent as well as submergent macrophytes, particulate organic matter, dissolved organic carbon, and invertebrates. The samples were collected to compare the biofilm signatures of each wetland in relation to the heterotrophic processes caused by the assimilation of oil sands-derived hydrocarbons and autochthonous detrital pools.

  8. Microbial characterization for the Source-Term Waste Test Program (STTP) at Los Alamos

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, P.A.; Strietelmeier, B.A.; Pansoy-Hjelvik, M.E.; Villarreal, R.

    1999-04-01

    The effects of microbial activity on the performance of the proposed underground nuclear waste repository, the Waste Isolation Pilot Plant (WIPP) at Carlsbad, New Mexico are being studied at Los Alamos National Laboratory (LANL) as part of an ex situ large-scale experiment. Actual actinide-containing waste is being used to predict the effect of potential brine inundation in the repository in the distant future. The study conditions are meant to simulate what might exist should the underground repository be flooded hundreds of years after closure as a result of inadvertent drilling into brine pockets below the repository. The Department of Energy (DOE) selected LANL to conduct the Actinide Source-Term Waste Test Program (STTP) to confirm the predictive capability of computer models being developed at Sandia National Laboratory.

  9. Influence of transport from urban sources and domestic biomass combustion on the air quality of a mountain area.

    Science.gov (United States)

    Petracchini, Francesco; Romagnoli, Paola; Paciucci, Lucia; Vichi, Francesca; Imperiali, Andrea; Paolini, Valerio; Liotta, Flavia; Cecinato, Angelo

    2017-02-01

    The environmental influence of biomass burning for civil uses was investigated through the determination of several air toxicants in the town of Leonessa and its surroundings, in the mountain region of central Italy. Attention was focussed on PM 10 , polycyclic aromatic hydrocarbons (PAHs) and regulated gaseous pollutants (nitrogen dioxide, ozone and benzene). Two in-field campaigns were carried out during the summer 2012 and the winter 2013. Contemporarily, air quality was monitored in Rome and other localities of Lazio region. In the summer, all pollutants, with the exception of ozone, were more abundant in Rome. On the other hand, in the winter, PAH concentration was higher in Leonessa (15.8 vs. 7.0 ng/m 3 ), while PM 10 was less concentrated (22 vs. 34 μg/m 3 ). Due to lack of other important sources and to limited impact of vehicle traffic, biomass burning was identified as the major PAH source in Leonessa during the winter. This hypothesis was confirmed by PAH molecular signature of PM 10 (i.e. concentration diagnostic ratios and 206 ion mass trace in the chromatograms). A similar phenomenon (i.e. airborne particulate levels similar to those of the capital city but higher PAH loads) was observed in other locations of the province, suggesting that uncontrolled biomass burning contributed to pollution across the Rome metropolitan area.

  10. Microalgae biomass growth using primary treated wastewater as nutrient source and their potential use for lipids production

    Science.gov (United States)

    Frementiti, Anastacia; Aravantinou, Andriana F.; Manariotis, Ioannis D.

    2015-04-01

    The great demand for energy, the rising price of the crude oil and the rapid decrease of the supply of fossil fuels are the main reasons that have increased the interest for the production of fuels from renewable resources. Microalgae are considered to be the most promising new source of biomass and biofuels, since their lipid content in some cases is up to 70%. The microalgal growth and its metabolism processes are essential in wastewater treatment with many economical prospects. The aim of this work was to evaluate the algal production in a laboratory scale open pond. The pond had a working volume of 30 L and was fed with sterilized primary treated wastewater. Chlorococcum sp. was used as a model microalgal. Experiments were conducted under controlled environmental conditions in order to investigate the removal of nutrients, biomass growth, and lipids accumulation in microalgae. Chlorococcum sp. cultures behavior was investigated under batch, fill and draw, and continuous operation mode, at two different radiation intensities (100 and 200 μmol/m2s). The maximum biomass concentration of 630 mg/L was observed with the fill and draw mode. Moreover, the growth rates of microalgal biomass were depended on the influent nutrients concentration. Specifically, the phosphates were the limiting factor for biomass growth in continuous condition; the phosphates removal in this condition, reached a 100%. Chemical demand oxygen (COD) was not removed efficiently by Chlorococcum sp. since it was an autotrophic microalgal with no organic carbon demands for its growth. The lipids content in the dry weight of Chlorococcum sp. ranged from 1 to 9% depending on the concentration of nutrients and the operating conditions.

  11. Constraining Biomarkers of Dissolved Organic Matter Sourcing Using Microbial Incubations of Vascular Plant Leachates of the California landscape

    Science.gov (United States)

    Harfmann, J.; Hernes, P.; Chuang, C. Y.; Kaiser, K.; Spencer, R. G.; Guillemette, F.

    2017-12-01

    Source origin of dissolved organic matter (DOM) is crucial in determining reactivity, driving chemical and biological processing of carbon. DOM source biomarkers such as lignin (a vascular plant marker) and D-amino acids (bacterial markers) are well-established tools in tracing DOM origin and fate. The development of high-resolution mass spectrometry and optical studies has expanded our toolkit; yet despite these advances, our understanding of DOM sources and fate remains largely qualitative. Quantitative data on DOM pools and fluxes become increasingly necessary as we refine our comprehension of its composition. In this study, we aim to calibrate and quantify DOM source endmembers by performing microbial incubations of multiple vascular plant leachates, where total DOM is constrained by initial vascular plant input and microbial production. Derived endmembers may be applied to endmember mixing models to quantify DOM source contributions in aquatic systems.

  12. Potential sources of hydrocarbons and their microbial degradation in sediments from the deep geothermal Lusi site, Indonesia

    Science.gov (United States)

    Krueger, Martin; Mazzini, Adriano; Scheeder, Georg; Blumenberg, Martin

    2017-04-01

    The Lusi eruption represents one of the largest ongoing sedimentary hosted geothermal systems, which started in 2006 following an earthquake on Java Island. Since then it has been continuously producing hot and hydrocarbon rich mud from a central crater with peaks reaching 180.000 m3 per day. Numerous investigations focused on the study of microbial communities which thrive at offshore methane and oil seeps and mud volcanoes, however very little has been done on onshore seeping structures. Lusi represents a unique opportunity to complete a comprehensive study of onshore microbial communities fed by the seepage of CH4 as well as of liquid hydrocarbons originating from one or more km below the surface. While the source of the methane at Lusi is unambiuous, the origin of the seeping oil is still discussed. Both, source and maturity estimates from biomarkers, are in favor of a type II/III organic matter source. Likely the oils were formed from the studied black shales (deeper Ngimbang Fm.) which contained a Type III component in the Type II predominated organic matter. In all samples large numbers of active microorganisms were present. Rates for aerobic methane oxidation were high, as was the potential of the microbial communities to degrade different hydrocarbons. The data suggests a transition of microbial populations from an anaerobic, hydrocarbon-driven metabolism in fresher samples from center or from small seeps to more generalistic, aerobic microbial communities in older, more consolidated sediments. Ongoing microbial activity in crater sediment samples under high temperatures (80-95C) indicate a deep origin of the involved microorganisms. First results of molecular analyses of the microbial community compositions confirm the above findings. This study represents an initial step to better understand onshore seepage systems and provides an ideal analogue for comparison with the better investigated offshore structures.

  13. Algal biomass harvesting by graft copolymer of polyacrylamide on guar gum (GGg-PAM: a sustainable method for alternative source of energy

    Directory of Open Access Journals (Sweden)

    Pinki Pal

    2016-09-01

    Full Text Available Microalgal cells has been utilized as a rich source of food, feed and fuel. The process of concentrating algal cells from water suspension is called harvesting. This article deals with the algal biomass harvesting by flocculation process using acrylamide grafted guar gum. Acrylamide has been successfully grafted onto the backbone of guar gum by microwave initiated method in which microwave radiation alone (without chemical free radical initiator is used to initiate the grafting reaction. Simultaneously with the synthesis of graft copolymer, water removal capability of various grades of GGg-PAM have also been studied as a flocculant for algal biomass harvesting through standard jar test procedure for collection of algal biomass. The collected biomass can be hand carried. The collected biomass has been characterized in terms of crude fat content and elemental composition. Calorific value of this collected biomass has also been theoretically calculated.

  14. Biogas Production from Protein-Rich Biomass: Fed-Batch Anaerobic Fermentation of Casein and of Pig Blood and Associated Changes in Microbial Community Composition

    Science.gov (United States)

    Kovács, Etelka; Wirth, Roland; Maróti, Gergely; Bagi, Zoltán; Rákhely, Gábor; Kovács, Kornél L.

    2013-01-01

    It is generally accepted as a fact in the biogas technology that protein-rich biomass substrates should be avoided due to inevitable process inhibition. Substrate compositions with a low C/N ratio are considered difficult to handle and may lead to process failure, though protein-rich industrial waste products have outstanding biogas generation potential. This common belief has been challenged by using protein-rich substrates, i.e. casein and precipitated pig blood protein in laboratory scale continuously stirred mesophilic fed-batch biogas fermenters. Both substrates proved suitable for sustained biogas production (0.447 L CH4/g protein oDM, i.e. organic total solids) in high yield without any additives, following a period of adaptation of the microbial community. The apparent key limiting factors in the anaerobic degradation of these proteinaceous materials were the accumulation of ammonia and hydrogen sulfide. Changes in time in the composition of the microbiological community were determined by next-generation sequencing-based metagenomic analyses. Characteristic rearrangements of the biogas-producing community upon protein feeding and specific differences due to the individual protein substrates were recognized. The results clearly demonstrate that sustained biogas production is readily achievable, provided the system is well-characterized, understood and controlled. Biogas yields (0.45 L CH4/g oDM) significantly exceeding those of the commonly used agricultural substrates (0.25-0.28 L CH4/g oDM) were routinely obtained. The results amply reveal that these high-energy-content waste products can be converted to biogas, a renewable energy carrier with flexible uses that can replace fossil natural gas in its applications. Process control, with appropriate acclimation of the microbial community to the unusual substrate, is necessary. Metagenomic analysis of the microbial community by next-generation sequencing allows a precise determination of the alterations in

  15. Biogas production from protein-rich biomass: fed-batch anaerobic fermentation of casein and of pig blood and associated changes in microbial community composition.

    Directory of Open Access Journals (Sweden)

    Etelka Kovács

    Full Text Available It is generally accepted as a fact in the biogas technology that protein-rich biomass substrates should be avoided due to inevitable process inhibition. Substrate compositions with a low C/N ratio are considered difficult to handle and may lead to process failure, though protein-rich industrial waste products have outstanding biogas generation potential. This common belief has been challenged by using protein-rich substrates, i.e. casein and precipitated pig blood protein in laboratory scale continuously stirred mesophilic fed-batch biogas fermenters. Both substrates proved suitable for sustained biogas production (0.447 L CH4/g protein oDM, i.e. organic total solids in high yield without any additives, following a period of adaptation of the microbial community. The apparent key limiting factors in the anaerobic degradation of these proteinaceous materials were the accumulation of ammonia and hydrogen sulfide. Changes in time in the composition of the microbiological community were determined by next-generation sequencing-based metagenomic analyses. Characteristic rearrangements of the biogas-producing community upon protein feeding and specific differences due to the individual protein substrates were recognized. The results clearly demonstrate that sustained biogas production is readily achievable, provided the system is well-characterized, understood and controlled. Biogas yields (0.45 L CH4/g oDM significantly exceeding those of the commonly used agricultural substrates (0.25-0.28 L CH4/g oDM were routinely obtained. The results amply reveal that these high-energy-content waste products can be converted to biogas, a renewable energy carrier with flexible uses that can replace fossil natural gas in its applications. Process control, with appropriate acclimation of the microbial community to the unusual substrate, is necessary. Metagenomic analysis of the microbial community by next-generation sequencing allows a precise determination of the

  16. Microbial biomass, microbial diversity, soil carbon storage, and stability after incubation of soil from grass-clover pastures of different age

    DEFF Research Database (Denmark)

    Müller-Stöver, Dorette Sophie; Hauggaard-Nielsen, Henrik; Eriksen, Jørgen

    2012-01-01

    A laboratory incubation study with clover grass pasture soils of seven different ages (0, 1, 2, 3, 4, 5, and 16 production years) was carried out to determine initial soil carbon (C) and nitrogen (N) stocks and potentials for greenhouse gas emissions (N2O and CO2). Compared with the soil from...... the recently established pasture, an increase of total soil C and N was observed along with pasture age. Greenhouse gas emissions were low and not significantly different among the soils from younger pastures (0-5 years), but especially N2O emissions increased markedly in the soil from 16-year-old grass......-clover. Low emissions might mainly be due to an early C limitation occurring in the soils from younger pastures, which was also corroborated by decreasing levels of cold water-extractable C and early shifts within the microbial community. However, higher emissions from the old pasture soil were offset by its...

  17. GIS Application to Define Biomass Collection Points as Sources for Linear Programming of Delivery Networks

    NARCIS (Netherlands)

    Velazquez-Marti, B.; Annevelink, E.

    2009-01-01

    Much bio-energy can be obtained from wood pruning operations in forests and fruit orchards. Several spatial studies have been carried out for biomass surveys, and many linear programming models have been developed to model the logistics of bio-energy chains. These models can assist in determining

  18. Anaerobic digestion of macroalgal biomass and sediments sourced from the Orbetello lagoon, Italy

    International Nuclear Information System (INIS)

    Migliore, G.; Alisi, C.; Sprocati, A.R.; Massi, E.; Ciccoli, R.; Lenzi, M.; Wang, A.; Cremisini, C.

    2012-01-01

    The anaerobic digestion of marine macroalgae biomass could meet two currently important needs, the mitigation of the eutrophication effects and the production of renewable energy. Because of the abundance of seaweed biomass its conversion can be highly desirable and convenient, mostly for countries with long coastlines or eutrophic environments. The aim of the present work is to carry out an exploratory study of biogas production from macroalgal biomass collected from the Orbetello lagoon (Tuscany, Italy) by solely exploiting the intrinsic degradation potential of the ecosystem. A fresh algae mix and sediments has been used, as both feed and inoculum of an anaerobic digestion process under psychro-mesophilic, mesophilic and thermophilic conditions, in batch reactors, without any washing and drying treatment. The presence of sediment proved to be crucial in order to achieve a good methane yield (methane yield of 380 dm 3 kg −1 VS added ) comparable with literature data obtained through different approaches. The results gave evidence that such an approach will have to be considered when planning a selective anaerobic digestion of macroalgae that could be useful in local applications for coasts and eutrophic lagoons affected by seasonal or frequent algal blooms. -- Highlights: ► Biogas production from macroalgal biomass with minimal energy input is proposed. ► Psychro-mesophilic, mesophilic and thermophilic conditions were compared. ► Highly adapted bacterial pool was crucial to achieve a good methane yield. ► The applied process exploits the intrinsic degradation potential of the ecosystem.

  19. Microbial biomass and organic nutrients in the deep-sea sediments of the Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Raghukumar, C.; Sheelu, G.; LokaBharathi, P.A.; Nair, S.; Mohandass, C.

    PMNprogramoftheDepartmentofOceanDevelopment,GovernmentofIndia.TheauthorsarethankfultothescientistsandcrewAASidorentzoforcooperationandassistanceduringthelongcruisesinthesamplingarea.The authorsalsowishtothankMs.GowriRivonkarfortechnicalassistanceinthelaboratory.NIOContributionNo.3509.ThispaperispartoftheseriespublishedinthespecialissueofMarineGeoresourcesandGeotechnology,Volume18,Number3,2000. AddresscorrespondencetoChandralataRaghukumar,NationalInstituteof...%)wastwotimesmorethanthatofthe MicrobialBiomassandOrganicNutrientsinCIOB 9 Figure4.(a)± (e)ConcentrationofLOM,TOC,andlivingbiomass-Cin® vecoresatdiŒerentdepths. bacterialisolates(34%).Ontheotherhand,numberofbacterialisolatesproducingproteasewere2.5timesmorethanthefungalisolates...

  20. Determining contributions of biomass burning and other sources to fine particle contemporary carbon in the western United States

    Science.gov (United States)

    Holden, Amanda S.; Sullivan, Amy P.; Munchak, Leigh A.; Kreidenweis, Sonia M.; Schichtel, Bret A.; Malm, William C.; Collett, Jeffrey L., Jr.

    2011-02-01

    Six-day integrated fine particle samples were collected at urban and rural sampling sites using Hi-Volume samplers during winter and summer 2004-2005 as part of the IMPROVE (Interagency Monitoring of PROtected Visual Environments) Radiocarbon Study. Filter samples from six sites (Grand Canyon, Mount Rainier, Phoenix, Puget Sound, Rocky Mountain National Park, and Tonto National Monument) were analyzed for levoglucosan, a tracer for biomass combustion, and other species by High-Performance Anion-Exchange Chromatography with Pulsed Amperometric Detection (HPAEC-PAD). Contemporary carbon concentrations were available from previous carbon isotope measurements at Lawrence Livermore National Laboratory. Primary contributions of biomass burning to measured fine particle contemporary carbon were estimated for residential wood burning (winter) and wild/prescribed fires (summer). Calculated contributions ranged from below detection limit to more than 100% and were typically higher at rural sites and during winter. Mannitol, a sugar alcohol emitted by fungal spores, was analyzed and used to determine contributions of fungal spores to fine particle contemporary carbon. Contributions reached up to 13% in summer samples, with higher contributions at rural sites. Concentrations of methyltetrols, oxidation products of isoprene, were also measured by HPAEC-PAD. Secondary organic aerosol (SOA) from isoprene oxidation was estimated to contribute up to 22% of measured contemporary carbon. For each sampling site, a substantial portion of the contemporary carbon was unexplained by primary biomass combustion, fungal spores, or SOA from isoprene oxidation. This unexplained fraction likely contains contributions from other SOA sources, including oxidation products of primary smoke emissions and plant emissions other than isoprene, as well as other primary particle emissions from meat cooking, plant debris, other biological aerosol particles, bio-diesel combustion, and other sources. Loss

  1. Sustainable carbon sources for microbial organic acid production with filamentous fungi.

    Science.gov (United States)

    Dörsam, Stefan; Fesseler, Jana; Gorte, Olga; Hahn, Thomas; Zibek, Susanne; Syldatk, Christoph; Ochsenreither, Katrin

    2017-01-01

    The organic acid producer Aspergillus oryzae and Rhizopus delemar are able to convert several alternative carbon sources to malic and fumaric acid. Thus, carbohydrate hydrolysates from lignocellulose separation are likely suitable as substrate for organic acid production with these fungi. Before lignocellulose hydrolysate fractions were tested as substrates, experiments with several mono- and disaccharides, possibly present in pretreated biomass, were conducted for their suitability for malic acid production with A. oryzae. This includes levoglucosan, glucose, galactose, mannose, arabinose, xylose, ribose, and cellobiose as well as cheap and easy available sugars, e.g., fructose and maltose. A. oryzae is able to convert every sugar investigated to malate, albeit with different yields. Based on the promising results from the pure sugar conversion experiments, fractions of the organosolv process from beechwood ( Fagus sylvatica ) and Miscanthus giganteus were further analyzed as carbon source for cultivation and fermentation with A. oryzae for malic acid and R. delemar for fumaric acid production. The highest malic acid concentration of 37.9 ± 2.6 g/L could be reached using beechwood cellulose fraction as carbon source in bioreactor fermentation with A. oryzae and 16.2 ± 0.2 g/L fumaric acid with R. delemar . We showed in this study that the range of convertible sugars for A. oryzae is even higher than known before. We approved the suitability of fiber/cellulose hydrolysate obtained from the organosolv process as carbon source for A. oryzae in shake flasks as well as in a small-scale bioreactor. The more challenging hemicellulose fraction of F. sylvatica was also positively evaluated for malic acid production with A. oryzae .

  2. Comparative effects of application of coated and non-coated urea in clayey and sandy paddy soil microcosms examined by the 15N tracer technique. 2. Effects on soil microbial biomass N and microbial 15N immobilization

    International Nuclear Information System (INIS)

    Acquaye, Solomon; Inubushi, Kazuyuki

    2004-01-01

    Nitrogen fertilizer and soil types exert an impact on plant and soil microbial biomass (SMB). A 15 N tracer experiment was conducted to compare the effects of the application of controlled-release coated urea (CRCU) and urea on SMB in gley (clayey) and sandy paddy soils. The fertilizers were applied at the rate of 8 g N m -2 for CRCU as deep-side placement and 10 g N m -2 for urea mixed into soil or applied into floodwater. The soil type and soil layer (surface: few millimeter depth of surface soil to include benthic algae; subsurface: 1 to 20 cm depth), but not the fertilizer type, affected the amount of microbial biomass N (B N ). On an area basis, subsurface soil layers contained about 2-3 times the amount of B N in the surface layers. The seasonal average B N amount i.e. at 1 to 20 cm depth, in the gley soil was 1.67 g N m -2 , compared to 1.20 g N m -2 for the sandy soil. The proportion of B N in total soil N was significantly influenced by the soil type and soil layer, and was higher for the surface layers of both soils and subsurface layer of the sandy soil than for the subsurface layer of gley soil. Soil type, soil layer, and fertilizer type significantly influenced the amount of microbial biomass 15 N (B 15N ). Unlike B N , the amount of B 15N was significantly higher in the surface (11.9-177.3 mg N m -2 ) than in the subsurface soil layers (4.8-83.6 mg N m -2 ), especially with urea application between 60 and 120 DAT (days after transplanting). At 30 DAT, the subsurface layer of the sandy soil showed a higher B 15N (218 mg N m -2 ) amount than the surface layer (133.4 mg N m -2 ). Sandy soil (4.8-218 mg N m -2 ) and urea (6.2-218 mg N m -2 ) induced a larger increase of the amount of B 15 N than the gley soil (6.2-83.6 mg N m -2 ) and CRCU (4.8-40 mg Nm -2 ). Again, the sandy soil, surface soil layers, and urea induced a higher proportion (%) of B 15N in B N than the gley soil, subsurface soil layers, and CRCU, respectively. The soil type affected B N

  3. Recent innovation in microbial source tracking using bacterial real-time PCR markers in shellfish

    International Nuclear Information System (INIS)

    Mauffret, A.; Mieszkin, S.; Morizur, M.; Alfiansah, Y.; Lozach, S.; Gourmelon, M.

    2013-01-01

    Highlights: ► DNA extraction from intravalvular liquid is promising for microbial source tracking in oysters. ► Host-associated bacterial markers in shellfish digestive tissues were difficult to assess with real-time PCR. ► DNA extracts from shellfish flesh appeared to have low inhibitor levels but low marker levels. ► Protocol transfer from one shellfish species to another does not appear possible. -- Abstract: We assessed the capacity of real-time PCR markers to identify the origin of contamination in shellfish. Oyster, cockles or clams were either contaminated with fecal materials and host-associated markers designed from Bacteroidales or Catellicoccus marimammalium 16S RNA genes were extracted from their intravalvular liquid, digestive tissues or shellfish flesh. Extraction of bacterial DNA from the oyster intravalvular liquid with FastDNA spin kit for soil enabled the selected markers to be quantified in 100% of artificially contaminated samples, and the source of contamination to be identified in 13 out of 38 naturally contaminated batches from European Class B and Class C areas. However, this protocol did not enable the origin of the contamination to be identified in cockle or clam samples. Although results are promising for extracts from intravalvular liquid in oyster, it is unlikely that a single protocol could be the best across all bacterial markers and types of shellfish

  4. New particle formation and growth in biomass burning plumes: An important source of cloud condensation nuclei

    Science.gov (United States)

    Hennigan, Christopher J.; Westervelt, Daniel M.; Riipinen, Ilona; Engelhart, Gabriella J.; Lee, Taehyoung; Collett, Jeffrey L., Jr.; Pandis, Spyros N.; Adams, Peter J.; Robinson, Allen L.

    2012-05-01

    Experiments were performed in an environmental chamber to characterize the effects of photo-chemical aging on biomass burning emissions. Photo-oxidation of dilute exhaust from combustion of 12 different North American fuels induced significant new particle formation that increased the particle number concentration by a factor of four (median value). The production of secondary organic aerosol caused these new particles to grow rapidly, significantly enhancing cloud condensation nuclei (CCN) concentrations. Using inputs derived from these new data, global model simulations predict that nucleation in photo-chemically aging fire plumes produces dramatically higher CCN concentrations over widespread areas of the southern hemisphere during the dry, burning season (Sept.-Oct.), improving model predictions of surface CCN concentrations. The annual indirect forcing from CCN resulting from nucleation and growth in biomass burning plumes is predicted to be -0.2 W m-2, demonstrating that this effect has a significant impact on climate that has not been previously considered.

  5. Biomass as a Source of Renewable Energy in Spain: A Case Study in Regulating Renewable Energy

    OpenAIRE

    Sánchez Sáez, Antonio José

    2006-01-01

    This paper examines how, in Andalusia, the installation of plants producing biomass or processing electricity from renewable energies could conform to the public interest actions in Article 42 of the Andalusian Town Planning Act; and how the Andalusian Draft of Renewable Energies and Saving and Energy Efficiency proposes working out territorial plans for renewable energies for specific areas, where those zones enjoying the best conditions for the usage of these energies will be...

  6. An Evaluation of the Use of Biomass as an Energy Source: The Brazilian Alcohol Programme

    OpenAIRE

    Ferreira, Leo da Rocha; Tourinho, Octavio A.F.

    1987-01-01

    This paper discusses the prehmmaiy results of Brazil's Economic and Social Planmng lnst1tute's BIOMASS linear programming model with emphasis on three aspects: temporal and spatial crop mix patterns along the analysis horizon; evaluation of the social cost of alcohol fuel; and the impact of alcohol production on the balance of payments. Brazil's national alcohol programme (PROALCOOL) increases domestic costs but its impact on the balance of payments is positive and substantial.

  7. Determination of silicon in biomass and products of pyrolysis process via high-resolution continuum source atomic absorption spectrometry.

    Science.gov (United States)

    Nakadi, Flávio V; Prodanov, Caroline; Boschetti, Wiliam; Vale, Maria Goreti R; Welz, Bernhard; de Andrade, Jailson B

    2018-03-01

    Thermochemical processes can convert the biomass into fuels, such as bio-oil. The biomass submitted to pyrolysis process, such as fibers, are generally rich in silicon, an element that can lead to damages in an engine when there is high concentration in a fuel. High-resolution continuum source atomic absorption spectrometry (HR-CS AAS) is an interesting alternative for Si determination in the products and byproducts of the pyrolysis process because, besides the flame (F) and graphite furnace (GF) atomizers, it has enhanced the application of direct analysis of solid samples (SS) within GF. This study aimed the development of methods to determine Si in biomass samples, their products and byproducts using HR-CS AAS. A high-resolution continuum source atomic absorption spectrometer contrAA 700 equipped with F and GF atomizers was used throughout the study. HR-CS F AAS (λ = 251.611nm, 1 detection pixel, N 2 O/C 2 H 2 flame) was used to evaluate Si content in biomass and ash, after a microwave-assisted acid digestion with HNO 3 and HF. HR-CS GF AAS (T pyr = 1400°C, T atom = 2650°C) has evaluated Si in pyrolysis water and bio-oil at 251.611nm, and in peach pit biomass and ash at 221.174nm using SS, both wavelengths with 1 detection pixel. Rhodium (300μg) was applied as permanent modifier and 10μgPd + 6μg Mg were pipetted onto the standards/samples at each analysis. Three different biomass samples were studied: palm tree fiber, coconut fiber and peach pit, and three certified reference materials (CRM) were used to verify the accuracy of the methods. The figures of merit were LOD 0.09-20mgkg -1 , and LOQ 0.3-20mgkg -1 , considering all the methods. There were no significant differences between the CRM certified values and the determined ones, using a Student t-test with a confidence interval of 95% (n = 5). Si concentration ranged from 0.11-0.92% mm -1 , 1.1-1.7mgkg -1 , 3.3-13mgkg -1 , and 0.41-1.4%mm -1 , in biomass, bio-oil, pyrolysis water and ash, respectively

  8. Radiocarbon Analysis to Calculate New End-Member Values for Biomass Burning Source Samples Specific to the Bay Area

    Science.gov (United States)

    Yoon, S.; Kirchstetter, T.; Fairley, D.; Sheesley, R. J.; Tang, X.

    2017-12-01

    Elemental carbon (EC), also known as black carbon or soot, is an important particulate air pollutant that contributes to climate forcing through absorption of solar radiation and to adverse human health impacts through inhalation. Both fossil fuel combustion and biomass burning, via residential firewood burning, agricultural burning, wild fires, and controlled burns, are significant sources of EC. Our ability to successfully control ambient EC concentrations requires understanding the contribution of these different emission sources. Radiocarbon (14C) analysis has been increasingly used as an apportionment tool to distinguish between EC from fossil fuel and biomass combustion sources. However, there are uncertainties associated with this method including: 1) uncertainty associated with the isolation of EC to be used for radiocarbon analysis (e.g., inclusion of organic carbon, blank contamination, recovery of EC, etc.) 2) uncertainty associated with the radiocarbon signature of the end member. The objective of this research project is to utilize laboratory experiments to evaluate some of these uncertainties, particularly for EC sources that significantly impact the San Francisco Bay Area. Source samples of EC only and a mix of EC and organic carbon (OC) were produced for this study to represent known emission sources and to approximate the mixing of EC and OC that would be present in the atmosphere. These samples include a combination of methane flame soot, various wood smoke samples (i.e. cedar, oak, sugar pine, pine at various ages, etc.), meat cooking, and smoldering cellulose smoke. EC fractions were isolated using a Sunset Laboratory's thermal optical transmittance carbon analyzer. For 14C analysis, samples were sent to Woods Hole Oceanographic Institution for isotope analysis using an accelerated mass spectrometry. End member values and uncertainties for the EC isolation utilizing this method will be reported.

  9. The Use of Wood Biomass in the Regional System of Renewable Energy Sources as a Chance for the Region

    Directory of Open Access Journals (Sweden)

    Andrzej Kluczkowski

    2017-12-01

    Full Text Available The world needs energy. It is an obvious truth you do not need to prove. The modern world needs the electricity. With advancing civilization and the rate of consumption, and the demand for electricity is growing. At the same time, conventional resources are running out. This situation leads to the search for new renewable sources of energy. Therefore a crucial role of forests should be taken into consideration. The study shows that, in the relatively short term, the wood biomass (mainly forest will play a significant role in the regional energy system.

  10. Microbial surface displayed enzymes based biofuel cell utilizing degradation products of lignocellulosic biomass for direct electrical energy.

    Science.gov (United States)

    Fan, Shuqin; Hou, Chuantao; Liang, Bo; Feng, Ruirui; Liu, Aihua

    2015-09-01

    In this work, a bacterial surface displaying enzyme based two-compartment biofuel cell for the direct electrical energy conversion from degradation products of lignocellulosic biomass is reported. Considering that the main degradation products of the lignocellulose are glucose and xylose, xylose dehydrogenase (XDH) displayed bacteria (XDH-bacteria) and glucose dehydrogenase (GDH) displayed bacteria (GDH-bacteria) were used as anode catalysts in anode chamber with methylene blue as electron transfer mediator. While the cathode chamber was constructed with laccase/multi-walled-carbon nanotube/glassy-carbon-electrode. XDH-bacteria exhibited 1.75 times higher catalytic efficiency than GDH-bacteria. This assembled enzymatic fuel cell exhibited a high open-circuit potential of 0.80 V, acceptable stability and energy conversion efficiency. Moreover, the maximum power density of the cell could reach 53 μW cm(-2) when fueled with degradation products of corn stalk. Thus, this finding holds great potential to directly convert degradation products of biomass into electrical energy. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Biomassa e atividades microbianas em solo sob pastagem com diferentes lotações de ovinos Biomass and microbial activity in pasture soil under different sheep grazing pressure

    Directory of Open Access Journals (Sweden)

    Martha Regina Lucizano Garcia

    2007-04-01

    Full Text Available Os efeitos da lotação de animais na produção de ovinos têm sido bastante estudados. No entanto, informações sobre seus efeitos na biomassa e nas atividades microbianas e, em conseqüência, na fertilidade do solo de pastagens são escassas. Neste trabalho, os efeitos da lotação de ovinos (LO na biomassa e nas atividades microbianas responsáveis pela transformação dos compostos do C e N em solo de clima subtropical foram avaliados. As amostras de solo foram coletadas nas camadas de 0-10 e 10-20 cm de pastos com baixa LO (5 animais ha-1, alta LO (40-50 animais ha-1 e com ausência de animais, em um delineamento inteiramente casualizado em parcelas subdivididas, com seis repetições. Os maiores valores de biomassa microbiana e das atividades respiratória, nitrificante e enzimática (urease e protease foram encontrados nos solos dos pastos com baixa LO. Estes pastos também acumularam as maiores quantidades de matéria orgânica e N total. Essas variáveis foram reduzidas nos pastos sem animais ou com alta LO. Vegetação descontínua e intensa mineralização podem ter acarretado a diminuição dessas variáveis nos pastos com alta LO. Alta correlação foi obtida entre matéria orgânica, C orgânico e N total com as quantidades de biomassa microbiana e a atividade enzimática. A camada de 0-10 cm apresentou valores maiores das variáveis estudadas do que os encontrados na camada de 10-20 cm.The effect of grazing pressure in sheep production has been studied, but not in relation to soil microbiological parameters or the consequences on soil fertility. The effect of grazing pressure (GP by sheep on biomass and microbial activity related to C and N compounds cycling in subtropical region soil was studied. Soil samples were collected from the 0-10 cm and 10-20 cm layers in pastures with low GP (5 animals ha-1, high GP (40-50 animals ha-1 and in absence of animals, in a completely randomized design with 6 replicates. The highest values

  12. Mineralisation of low concentrations of organic compounds and microbial biomass in surface and vadose zone soils from the Swan Coastal Plain, Western Australia

    International Nuclear Information System (INIS)

    Franzmann, P. D.; Zappia, L. R.; Patterson, B. M.; Rayner, J.L.; Davis, G. B.

    1998-01-01

    Mineralisation rates for ring-labelled 14 C-atrazine, benzene, and toluene were determined for a number of Swan Coastal Plain soils which had not been previously in contact with these contaminants. Microbial biomass was estimated by phospholipid techniques in soil samples from the same sites. Mineralisation rates for the volatile aromatic hydrocarbons in the thin (up to 30 cm) surface soils (23.4-42.6 μmol/kg . day when fitted to zeroth-order rate kinetics) were appreciably faster than the mineralisation rates measured in soils collected from a depth of 1 m (0.11-3.0 μmol/kg per day). The pesticide atrazine was degraded slowly, with degradation rates in surface soils ranging from 1.22x10 -3 to 2.78x10 -4 μmol/kg . day, and those in soils at 1 m ranging from 5. 13x10 -4 to 3.1610 -4 μmol/kg per day. When mineralisation data were fitted to first-order kinetics then half-lives for atrazine mineralisation ranged from about 1 year in surface soils to 3.1-5.1 years in soils at 1 m. These rates were comparable to atrazine mineralisation rates measured in soils that had not been previously in contact with atrazine, as reported by others. The extent of mineralisation of the organic compounds v. time generally fitted better to zeroth-order kinetics than to first-order kinetics. Confidence in the determination of the mineralisation rate at slow rates of mineralisation was low (r 2 as low as 0.2 in plots of the extent of mineralisation v. time in zeroth-order and first-order plots for samples that showed slow mineralisation). Biomass, expressed as stationary phase Escherichia coli equivalents (SPEE), ranged from 1.4 x10 7 to 1x2x10 8 SPEE/g dry weight for surface soils, and from 8.6x10 5 to 7.3x10 6 SPEE/g dry weight for soils at 1 m. The phospholipids extracted from surface soils tended to contain higher proportions of unsaturated and hydroxy fatty acids than soils at 1 m, which contained higher relative concentrations of branched fatty acids, which is consistent with the

  13. Early warning system for detection of microbial contamination of source waters

    DEFF Research Database (Denmark)

    Mogensen, Claus Tilsted; Bentien, Anders; Lau, Mogens

    2011-01-01

    Ensuring chemical and microbial water quality is an ever increasing important issue world-wide. Currently, determination of microbial water quality is a time (and money) consuming manual laboratory process. We have developed and field-tested an online and real-time sensor for measuring the microb...

  14. Energy of the Earth. Geothermal and biomass energy sources for humanity

    International Nuclear Information System (INIS)

    2010-01-01

    The Earth feeds us but supplies its energy to us as well and in two ways: the heat coming from the Earth's core spreads through rocks and geologic fractures and heats the groundwater, in particular in volcanic and hydrothermal areas. This energy can be captured and directly used for district and space heating or converted into electricity. The Earth, thanks to photosynthesis, is also a formidable chemical factory. With the single energy coming from the sun, plants oxide water and convert the carbon from the air into sugars to make biomass. Cultures, agricultural and animal breeding wastes are as many resources for a renewable and greenhouse gas-free energy which can be converted into non-toxic chemical products, automotive fuels, heat and electricity. Both geothermal and biomass resources are far to have supplied their full potential. Production capacities are enormous and capable to answer the needs of a still growing up humanity. This book explains how we are going to exploit this energy wealth. (J.S.)

  15. Sago Biomass as a Sustainable Source for Biohydrogen Production by Clostridium butyricum A1

    Directory of Open Access Journals (Sweden)

    Mohamad Faizal Ibrahim

    2013-12-01

    Full Text Available Biohydrogen production from biomass is attracting many researchers in developing a renewable, clean and environmental friendly biofuel. The biohydrogen producer, Clostridium butyricum A1, was successfully isolated from landfill soil. This strain produced a biohydrogen yield of 1.90 mol H2/mol glucose with productivity of 170 mL/L/h using pure glucose as substrate. The highest cumulative biohydrogen collected after 24 h of fermentation was 2468 mL/L-medium. Biohydrogen fermentation using sago hampas hydrolysate produced higher biohydrogen yield (2.65 mol H2/mol glucose than sago pith residue (SPR hydrolysate that produced 2.23 mol H2/mol glucose. A higher biohydrogen productivity of 1757 mL/L/h was obtained when using sago hampas hydrolysate compared to when using pure glucose that has the productivity of 170 mL/L/h. A comparable biohydrogen production was also obtained by C. butyricum A1 when compared to C. butyricum EB6 that produced a biohydrogen yield of 2.50 mol H2/mol glucose using sago hampas hydrolysate as substrate. This study shows that the new isolate C. butyricum A1 together with the use of sago biomass as substrate is a promising technology for future biohydrogen production.

  16. Softwood forest thinning as a biomass source for ethanol production: A feasibility study for California

    Energy Technology Data Exchange (ETDEWEB)

    Kadam, Kiran L; Wooley, Robert J; Aden, Andrew; Nguyen, Quang A; Yancey, Mark A; Ferraro, Francis M [Colorado(United States)

    2000-07-01

    A plan has been put forth to strategically thin northern California forests to reduce fire danger and improve forest health. The resulting biomass residue, instead of being open burned, can be converted into ethanol that can be used as a fuel oxygenate or an octane enhancer. Economic potential for a biomass-to-ethanol facility using this softwood biomass was evaluated for two cases: Stand-alone and co-located. The co-located case refers to a specific site with an existing biomass power facility owned by Wheelabrator Environmental Systems Inc. near Martell, California. A two-stage dilute acid hydrolysis process is used for the production of ethanol from softwoods, and the residual lignin is used to generate steam and electricity. For a plant processing 800 dry tonnes per day of feedstock, the co-located case is an economically attractive concept. Total estimated capital investment is approximately $ 70 million for the co-located case. The resulting internal rate of return is about 24% using 25% equity financing. Hence, such a biomass-to-ethanol plant seems to be an appealing proposition for California, with ethanol replacing methyl tertiary-butyl ether, which is slated for a phaseout. [Spanish] Se ha desarrollado un plan para adelgazar estrategicamente los bosques del norte de California para reducir el peligro de incendio y mejorar la salud del bosque. El residuo resultante de biomasa en vez de ser quemado a la intemperie, puede ser convertido en etanol, el cual se puede utilizar como un combustible oxigenado o como un mejorador del octanaje. Se ha evaluado el potencial economico de una planta de conversion de biomasa a etanol utilizando la biomasa de las coniferas para dos opciones: Una planta independiente o una localizada junto a otra. El caso de la localizada una junto a otra se refiere a un lugar especifico con una instalacion ya existente de biomasa propiedad de Wheelabrator Environmental Systems Inc. cerca de Martell, California. Se utiliza un proceso de

  17. The Effect of Initial Inoculum Source on the Microbial Community Structure and Dynamics in Laboratory-Scale Sequencing Batch Reactors

    KAUST Repository

    Hernandez, Susana

    2011-07-01

    Understanding the factors that shapes the microbial community assembly in activated sludge wastewater treatment processes provide a conceptual foundation for improving process performance. The aim of this study was to compare two major theories (deterministic theory and neutral theory) regarding the assembly of microorganisms in activated sludge: Six lab-scale activated sludge sequencing batch reactors were inoculated with activated sludge collected from three different sources (domestic, industrial, and sugar industry WWTP). Additionally, two reactors were seeded with equal proportion of sludge from the three WWTPs. Duplicate reactors were used for each sludge source (i.e. domestic, industrial, sugar and mix). Reactors were operated in parallel for 11 weeks under identical conditions. Bacterial diversity and community structure in the eight SBRs were assessed by 16S rRNA gene pyrosequencing. The 16S rRNA gene sequences were analyzed using taxonomic and clustering analysis and by measuring diversity indices (Shannon-weaver and Chao1 indices). Cluster analysis revealed that the microbial community structure was dynamic and that replicate reactors evolved differently. Also the microbial community structure in the SBRs seeded with a different sludge did not converge after 11 weeks of operation under identical conditions. These results suggest that history and distribution of taxa in the source inoculum were stronger regulating factors in shaping bacterial community structure than environmental factors. This supports the neutral theory which states that the assembly of the local microbial community from the metacommunity is random and is regulated by the size and diversity of the metacommunity. Furthermore, sludge performance, measured by COD and ammonia removal, confirmed that broad-scale functions (e.g. COD removal) are not influenced by dynamics in the microbial composition, while specific functions (e.g. nitrification) are more susceptible to these changes.

  18. Assessment of the microbial growth potential of slow sand filtrate with the biomass production potential test in comparison with the assimilable organic carbon method.

    Science.gov (United States)

    van der Kooij, Dick; Veenendaal, Harm R; van der Mark, Ed J; Dignum, Marco

    2017-11-15

    Slow sand filtration is the final treatment step at four surface-water supplies in the Netherlands. The microbial growth potential (MGP) of the finished water was measured with the assimilable organic carbon (AOC) method using pure cultures and the biomass production potential (BPP) test. In the BPP test, water samples were incubated untreated at 25 °C and the active-biomass concentration was measured by adenosine tri-phosphate (ATP) analysis. Addition of a river-water inoculum improved the test performance and characteristic growth and maintenance profiles of the water were obtained. The maximum ATP concentration attained within seven days and the cumulative biomass production after 14 days of incubation (BPC 14 , d ng ATP L -1 ) showed highly significant and strong linear relationships with the AOC in the slow sand filtrates. The lowest AOC and BPC 14 levels were observed in the supplies applying dune filtration without ozonation in post treatment, with AOC/TOC = 1.7 ± 0.3 μg acetate-C equivalents mg -1 C and BPC 14 /TOC = 16.3 ± 2.2 d ng ATP mg -1 C, corresponding with 1.2 ± 0.19 ng ATP mg -1 C. These characteristics may represent the lowest specific MGP of natural organic matter achievable by biofiltration at temperatures ≤20 °C. The AOC and BPC 14 concentrations in the slow sand filtrate of the supply treating lake water by ozonation with granular-activated-carbon filtration and slow sand filtration as post treatment increased with decreasing temperature. The BPP test revealed that this slow sand filtrate sampled at 2 °C contained growth-promoting compounds that were not detected with the AOC test. These observations demonstrate the utility of the BPP test for assessing the MGP of drinking water and show the performance limits of biofiltration for MGP reduction. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Attribution of the Main Sources of Biomass Burning in South East Asia that Impact on Air Quality in Singapore

    Science.gov (United States)

    Hansen, A. B.; Kendall, E.; Chew, B. N.; Chong, W. M.; Gan, C.; Hort, M. C.; Shaw, F.; Witham, C. S.

    2017-12-01

    Biomass burning in South East Asia causes intense haze episodes in Singapore, these are of major concern to the local government and the population exposed to the haze. Using a Lagrangian dispersion model we have studied haze in the seven most recent years (2010 - 2016) to gain a deeper understanding of intense haze in Singapore. In this study, modelled haze time-series at one eastern and one western monitoring station in Singapore are compared to local observed PM10 and PM2.5 air concentrations. The haze time-series are broken down by season or month, source region, and monitoring location.The analysis, presented as time series and pie charts, illustrates the relative contribution to haze in Singapore from different regions, variations between seasons and the correlation of impact to the combined timing of burning activity and meteorological patterns. Air history maps, showing where air arriving in Singapore originates from and/or has travelled through, are used to isolate the meteorological dependence of impacts. These show a strong monsoonal variation and help explain the inter-annual differences between sources and actual concentrations of biomass burning PM in Singapore. For example, there is a strong correlation in 2013 between burning in Riau and haze in Singapore, but a weak correlation in other years when a significant part of haze originates from, e.g., Peninsula Malaysia, but emissions are seemingly negligible. We see that, in spite of the size of Singapore, there is significant difference in concentrations and major contributing source regions between the two monitoring stations, annually and seasonally. The differences at the two monitoring stations are seen in varying degrees in the years 2011, 2012, 2014, and 2015, throughout different seasons. Although only biomass burning is considered in the simulations, our modelled results are in good agreement with local observations. We have identified the source regions with the biggest contributions to haze

  20. Mild-temperature thermochemical pretreatment of green macroalgal biomass: Effects on solubilization, methanation, and microbial community structure.

    Science.gov (United States)

    Jung, Heejung; Baek, Gahyun; Kim, Jaai; Shin, Seung Gu; Lee, Changsoo

    2016-01-01

    The effects of mild-temperature thermochemical pretreatments with HCl or NaOH on the solubilization and biomethanation of Ulva biomass were assessed. Within the explored region (0-0.2M HCl/NaOH, 60-90°C), both methods were effective for solubilization (about 2-fold increase in the proportion of soluble organics), particularly under high-temperature and high-chemical-dose conditions. However, increased solubilization was not translated into enhanced biogas production for both methods. Response surface analysis statistically revealed that HCl or NaOH addition enhances the solubilization degree while adversely affects the methanation. The thermal-only treatment at the upper-limit temperature (90°C) was estimated to maximize the biogas production for both methods, suggesting limited potential of HCl/NaOH treatment for enhanced Ulva biomethanation. Compared to HCl, NaOH had much stronger positive and negative effects on the solubilization and methanation, respectively. Methanosaeta was likely the dominant methanogen group in all trials. Bacterial community structure varied among the trials according primarily to HCl/NaOH addition. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Metaproteome analysis to determine the metabolically active part of a thermophilic microbial community producing biogas from agricultural biomass.

    Science.gov (United States)

    Hanreich, Angelika; Heyer, Robert; Benndorf, Dirk; Rapp, Erdmann; Pioch, Markus; Reichl, Udo; Klocke, Michael

    2012-07-01

    Complex consortia of microorganisms are responsible for biogas production. A lot of information about the taxonomic structure and enzymatic potential of such communities has been collected by a variety of gene-based approaches, yet little is known about which of all the assumable metabolic pathways are active throughout the process of biogas formation. To tackle this problem, we established a protocol for the metaproteomic analysis of samples taken from biogas reactors fed with agricultural biomass. In contrast to previous studies where an anaerobic digester was fed with synthetic wastewater, the complex matrix in this study required the extraction of proteins with liquid phenol and the application of paper bridge loading for 2-dimensional gel electrophoresis. Proteins were subjected to nanoHPLC (high-performance liquid chromatography) coupled to tandem mass spectrometry for characterization. Several housekeeping proteins as well as methanogenesis-related enzymes were identified by a MASCOT search and de novo sequencing, which proved the feasibility of our approach. The establishment of such an approach is the basis for further metaproteomic studies of biogas-producing communities. In particular, the apparent status of metabolic activities within the communities can be monitored. The knowledge collected from such experiments could lead to further improvements of biogas production.

  2. Microbial activity and biomass of peats in relation to the intrinsic organic matter composition, pH, moisture, and C and N inputs

    Energy Technology Data Exchange (ETDEWEB)

    Amha Amde, Yosef

    2011-03-25

    Excessive decomposition of organic matter (OM) from the potting media (e.g. peat) is known to influence plant growth by decreasing the total porosity, altering the chemical properties (pH, electrical conductivity), and releasing organic compounds that might have phytotoxic or stimulating effects. When peats are used as constitutes of the potting media, they should, therefore, maintain stability during plant production. In this study, twenty peat samples from Estonia, Finland, Germany, Ireland, Latvia, Lithuania and Sweden were evaluated for their microbial activity (measured as CO{sub 2} and N{sub 2}O emissions) and biomass with a special emphasis to the intrinsic organic matter composition, pH, moisture, and C and N inputs as such information on a wide range of peat samples is largely missing from published literature. Overall, the whole peat samples were broadly classified into three distinct groups using the hierarchical cluster analysis: the Irish and two of German peats produced the lowest CO{sub 2} while most peats from Finland produced the highest CO{sub 2}. With few exceptions, peats from the Baltic States occupied the middle ranges. Excessive decomposition of organic matter in the Finish peats might have unintended consequences if these peats are used for long-term pot plant production. With regard to botanical composition, peats containing Sphagnum imbricatum produced the lowest CO{sub 2} and S. angustifolium dominated peats mostly produced the highest CO{sub 2}. (orig.)

  3. Impact of Trichloroethylene Exposure on the Microbial Diversity and Protein Expression in Anaerobic Granular Biomass at 37°C and 15°C

    Directory of Open Access Journals (Sweden)

    Alma Siggins

    2012-01-01

    Full Text Available Granular biomass from a laboratory-scale anaerobic bioreactor trial was analysed to identify changes in microbial community structure and function in response to temperature and trichloroethylene (TCE. Two bioreactors were operated at 37°C, while two were operated at 15°C. At the time of sampling, one of each temperature pair of bioreactors was exposed to process failure-inducing concentrations of TCE (60 mg L−1 while the other served as a TCE-free control. Bacterial community structure was investigated using denaturing gradient gel electrophoresis (DGGE and 16S rRNA gene clone library analysis. Temperature was identified as an important factor for bacterial community composition, while minor differences were associated with trichloroethylene supplementation. Proteobacteria was the dominant phylum in all bioreactors, while clone library analysis revealed a higher proportion of Bacteroidetes-, Chloroflexi-, and Firmicutes-like clones at 15°C than at 37°C. Comparative metaproteomics in the presence and absence of TCE was carried out by two-dimensional gel electrophoresis (2-DGE, and 28 protein spots were identified, with putative functions related to cellular processes, including methanogenesis, glycolysis, the glyoxylate cycle, and the methyl malonyl pathway. A good agreement between metaproteomic species assignment and phylogenetic information was observed, with 10 of the identified proteins associated with members of the phylum Proteobacteria.

  4. DETERMINATION OF ENZYMES PRODUCED BY CERIPORIOPSIS SUBVERMISPORA DURING PRETREATMENT OF DIFFERENT BIOMASS SOURCES

    Directory of Open Access Journals (Sweden)

    Miroslav Ondrejovič

    2012-02-01

    Full Text Available The aim of this paper was to study of lignocellulolytic enzymes producing by Ceriporiopsis subvermispora during its cultivation on three types of plant biomass differentiated by chemical composition and physical properties (wheat straw, pine and poplar wood. The activity of lignocellulolytic enzymes in cultivation medium was determined by catalytic transformation of their natural substrates to products which were detected by photometric methods. Cellulase activities were very low while xylanases predominated. Wheat straw was best substrate for production of cellulases (4.38 U/mL and xylanases (23.34 U/mL. The maximum activity of cellulase and xylanase was reached at 8th and 3rd day, respectively. Laccase activity reached the maximum after 16 days and then gradually decreased. The best substrate for production of laccases was poplar wood (1.67 U/mL.

  5. Bioconversion of oil sludge into biomass of lipid metabolites for use as a source of biofuel

    Science.gov (United States)

    Shchemelinina, T. N.; Matistov, N. V.; Markarova, M. Yu; Anchugova, E. M.

    2018-01-01

    The possibilities for the generation of biofuel from the results of the accumulation of lipids in oil-contaminated environments were studied. This type of accumulation occurs in the biomass of yeast strains Rhodotorula sp. VKM Y-2993D; in bacteria like Pseudomonas libanensis B-3041D and in consortia of microalgal strains such as Acutodesmus obliquus Syko-A Ch-055-12, Chlorella sp. SYKO A Ch-011-10, Monoraphidium sp., and Anabaena sp. The most promising of these for processing petroleum hydrocarbons into biofuels was found to be the consortium of microalgal strains, the content of palmitic acid of which reached 49.0 %, thereby achieving a mid-range cetane number.

  6. An assessment of biomass as an energy source: the case of energy from waste

    International Nuclear Information System (INIS)

    Clarke, Alexi; Elliott, David

    2002-01-01

    Given that biomass plays a part in a complex natural cycle of decay and re-growth, providing the feedstock for a variety of often slow and subtle natural cycles, there are clearly limits to how much can be burnt without undermining key biological processes. This paper focuses on energy from waste, since, we argue, waste combustion is one of the more problematic options in terms of environmental sustainability, and we attempt to make a preliminary life cycle assessment of its impact. This suggests that the overall impact will depend not just on the total amount of wastes combusted, but also on their specific organic qualities, and on their role if they had not been diverted, in particular their role in maintaining soil quality. Given that soil plays a significant part in the process of carbon sequestration, we argue that consideration should be given to the concept of conservation of organic potentials. (Author)

  7. Examining effective use of data sources and modeling algorithms for improving biomass estimation in a moist tropical forest of the Brazilian Amazon

    Science.gov (United States)

    Yunyun Feng; Dengsheng Lu; Qi Chen; Michael Keller; Emilio Moran; Maiza Nara dos-Santos; Edson Luis Bolfe; Mateus Batistella

    2017-01-01

    Previous research has explored the potential to integrate lidar and optical data in aboveground biomass (AGB) estimation, but how different data sources, vegetation types, and modeling algorithms influence AGB estimation is poorly understood. This research conducts a comparative analysis of different data sources and modeling approaches in improving AGB estimation....

  8. Reactor performances and microbial communities of biogas reactors: effects of inoculum sources.

    Science.gov (United States)

    Han, Sheng; Liu, Yafeng; Zhang, Shicheng; Luo, Gang

    2016-01-01

    Anaerobic digestion is a very complex process that is mediated by various microorganisms, and the understanding of the microbial community assembly and its corresponding function is critical in order to better control the anaerobic process. The present study investigated the effect of different inocula on the microbial community assembly in biogas reactors treating cellulose with various inocula, and three parallel biogas reactors with the same inoculum were also operated in order to reveal the reproducibility of both microbial communities and functions of the biogas reactors. The results showed that the biogas production, volatile fatty acid (VFA) concentrations, and pH were different for the biogas reactors with different inocula, and different steady-state microbial community patterns were also obtained in different biogas reactors as reflected by Bray-Curtis similarity matrices and taxonomic classification. It indicated that inoculum played an important role in shaping the microbial communities of biogas reactor in the present study, and the microbial community assembly in biogas reactor did not follow the niche-based ecology theory. Furthermore, it was found that the microbial communities and reactor performances of parallel biogas reactors with the same inoculum were different, which could be explained by the neutral-based ecology theory and stochastic factors should played important roles in the microbial community assembly in the biogas reactors. The Bray-Curtis similarity matrices analysis suggested that inoculum affected more on the microbial community assembly compared to stochastic factors, since the samples with different inocula had lower similarity (10-20 %) compared to the samples from the parallel biogas reactors (30 %).

  9. Biomass [updated

    Energy Technology Data Exchange (ETDEWEB)

    Turhollow Jr, Anthony F [ORNL

    2016-01-01

    Biomass resources and conversion technologies are diverse. Substantial biomass resources exist including woody crops, herbaceous perennials and annuals, forest resources, agricultural residues, and algae. Conversion processes available include fermentation, gasification, pyrolysis, anaerobic digestion, combustion, and transesterification. Bioderived products include liquid fuels (e.g. ethanol, biodiesel, and gasoline and diesel substitutes), gases, electricity, biochemical, and wood pellets. At present the major sources of biomass-derived liquid fuels are from first generation biofuels; ethanol from maize and sugar cane (89 billion L in 2013) and biodiesel from vegetable oils and fats (24 billion liters in 2011). For other than traditional uses, policy in the forms of mandates, targets, subsidies, and greenhouse gas emission targets has largely been driving biomass utilization. Second generation biofuels have been slow to take off.

  10. Variation in Microbial Identification System Accuracy for Yeast Identification Depending on Commercial Source of Sabouraud Dextrose Agar

    OpenAIRE

    Kellogg, James A.; Bankert, David A.; Chaturvedi, Vishnu

    1999-01-01

    The accuracy of the Microbial Identification System (MIS; MIDI, Inc.) for identification of yeasts to the species level was compared by using 438 isolates grown on prepoured BBL Sabouraud dextrose agar (SDA) and prepoured Remel SDA. Correct identification was observed for 326 (74%) of the yeasts cultured on BBL SDA versus only 214 (49%) of yeasts grown on Remel SDA (P < 0.001). The commercial source of the SDA used in the MIS procedure significantly influences the system’s accuracy.

  11. Variation in Microbial Identification System accuracy for yeast identification depending on commercial source of Sabouraud dextrose agar.

    Science.gov (United States)

    Kellogg, J A; Bankert, D A; Chaturvedi, V

    1999-06-01

    The accuracy of the Microbial Identification System (MIS; MIDI, Inc. ) for identification of yeasts to the species level was compared by using 438 isolates grown on prepoured BBL Sabouraud dextrose agar (SDA) and prepoured Remel SDA. Correct identification was observed for 326 (74%) of the yeasts cultured on BBL SDA versus only 214 (49%) of yeasts grown on Remel SDA (P < 0.001). The commercial source of the SDA used in the MIS procedure significantly influences the system's accuracy.

  12. Mesophilic and thermophilic conditions select for unique but highly parallel microbial communities to perform carboxylate platform biomass conversion.

    Directory of Open Access Journals (Sweden)

    Emily B Hollister

    Full Text Available The carboxylate platform is a flexible, cost-effective means of converting lignocellulosic materials into chemicals and liquid fuels. Although the platform's chemistry and engineering are well studied, relatively little is known about the mixed microbial communities underlying its conversion processes. In this study, we examined the metagenomes of two actively fermenting platform communities incubated under contrasting temperature conditions (mesophilic 40°C; thermophilic 55 °C, but utilizing the same inoculum and lignocellulosic feedstock. Community composition segregated by temperature. The thermophilic community harbored genes affiliated with Clostridia, Bacilli, and a Thermoanaerobacterium sp, whereas the mesophilic community metagenome was composed of genes affiliated with other Clostridia and Bacilli, Bacteriodia, γ-Proteobacteria, and Actinobacteria. Although both communities were able to metabolize cellulosic materials and shared many core functions, significant differences were detected with respect to the abundances of multiple Pfams, COGs, and enzyme families. The mesophilic metagenome was enriched in genes related to the degradation of arabinose and other hemicellulose-derived oligosaccharides, and the production of valerate and caproate. In contrast, the thermophilic community was enriched in genes related to the uptake of cellobiose and the transfer of genetic material. Functions assigned to taxonomic bins indicated that multiple community members at either temperature had the potential to degrade cellulose, cellobiose, or xylose and produce acetate, ethanol, and propionate. The results of this study suggest that both metabolic flexibility and functional redundancy contribute to the platform's ability to process lignocellulosic substrates and are likely to provide a degree of stability to the platform's fermentation processes.

  13. Microcosm studies on iron and arsenic mobilization from aquifer sediments under different conditions of microbial activity and carbon source

    Science.gov (United States)

    Duan, Mengyu; Xie, Zuoming; Wang, Yanxin; Xie, Xianjun

    2009-05-01

    Microcosm experiments were conducted to understand the mechanism of microbially mediated mobilization of Fe and As from high arsenic aquifer sediments. Arsenic-resistant strains isolated from aquifer sediments of a borehole specifically drilled for this study at Datong basin were used as inoculated strains, and glucose and sodium acetate as carbon sources for the experiments. In abiotic control experiments, the maximum concentrations of Fe and As were only 0.47 mg/L and 0.9 μg/L, respectively. By contrast, the maximum contents of Fe and As in anaerobic microcosm experiments were much higher (up to 1.82 mg/L and 12.91 μg/L, respectively), indicating the crucial roles of microbial activities in Fe and As mobilization. The observed difference in Fe and As release with different carbon sources may be related to the difference in growth pattern and composition of microbial communities that develop in response to the type of carbon sources.

  14. Cascading influence of inorganic nitrogen sources on DOM production, composition, lability and microbial community structure in the open ocean.

    Science.gov (United States)

    Goldberg, S J; Nelson, C E; Viviani, D A; Shulse, C N; Church, M J

    2017-09-01

    Nitrogen frequently limits oceanic photosynthesis and the availability of inorganic nitrogen sources in the surface oceans is shifting with global change. We evaluated the potential for abrupt increases in inorganic N sources to induce cascading effects on dissolved organic matter (DOM) and microbial communities in the surface ocean. We collected water from 5 m depth in the central North Pacific and amended duplicate 20 liter polycarbonate carboys with nitrate or ammonium, tracking planktonic carbon fixation, DOM production, DOM composition and microbial community structure responses over 1 week relative to controls. Both nitrogen sources stimulated bulk phytoplankton, bacterial and DOM production and enriched Synechococcus and Flavobacteriaceae; ammonium enriched for oligotrophic Actinobacteria OM1 and Gammaproteobacteria KI89A clades while nitrate enriched Gammaproteobacteria SAR86, SAR92 and OM60 clades. DOM resulting from both N enrichments was more labile and stimulated growth of copiotrophic Gammaproteobacteria (Alteromonadaceae and Oceanospirillaceae) and Alphaproteobacteria (Rhodobacteraceae and Hyphomonadaceae) in weeklong dark incubations relative to controls. Our study illustrates how nitrogen pulses may have direct and cascading effects on DOM composition and microbial community dynamics in the open ocean. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  15. Mapping carbon storage in urban trees with multi-source remote sensing data: Relationships between biomass, land use, and demographics in Boston neighborhoods

    International Nuclear Information System (INIS)

    Raciti, Steve M.; Hutyra, Lucy R.; Newell, Jared D.

    2014-01-01

    High resolution maps of urban vegetation and biomass are powerful tools for policy-makers and community groups seeking to reduce rates of urban runoff, moderate urban heat island effects, and mitigate the effects of greenhouse gas emissions. We developed a very high resolution map of urban tree biomass, assessed the scale sensitivities in biomass estimation, compared our results with lower resolution estimates, and explored the demographic relationships in biomass distribution across the City of Boston. We integrated remote sensing data (including LiDAR-based tree height estimates) and field-based observations to map canopy cover and aboveground tree carbon storage at ∼ 1 m spatial scale. Mean tree canopy cover was estimated to be 25.5 ± 1.5% and carbon storage was 355 Gg (28.8 Mg C ha −1 ) for the City of Boston. Tree biomass was highest in forest patches (110.7 Mg C ha −1 ), but residential (32.8 Mg C ha −1 ) and developed open (23.5 Mg C ha −1 ) land uses also contained relatively high carbon stocks. In contrast with previous studies, we did not find significant correlations between tree biomass and the demographic characteristics of Boston neighborhoods, including income, education, race, or population density. The proportion of households that rent was negatively correlated with urban tree biomass (R 2 = 0.26, p = 0.04) and correlated with Priority Planting Index values (R 2 = 0.55, p = 0.001), potentially reflecting differences in land management among rented and owner-occupied residential properties. We compared our very high resolution biomass map to lower resolution biomass products from other sources and found that those products consistently underestimated biomass within urban areas. This underestimation became more severe as spatial resolution decreased. This research demonstrates that 1) urban areas contain considerable tree carbon stocks; 2) canopy cover and biomass may not be related to the demographic characteristics of Boston

  16. Mapping carbon storage in urban trees with multi-source remote sensing data: Relationships between biomass, land use, and demographics in Boston neighborhoods

    Energy Technology Data Exchange (ETDEWEB)

    Raciti, Steve M., E-mail: Steve.M.Raciti@Hofstra.edu [Department of Biology, Hofstra University, Gittleson Hall, Hempstead, NY 11549 (United States); Department of Earth and Environment, Boston University, 685 Commonwealth Ave., Boston, MA 02215 (United States); Hutyra, Lucy R.; Newell, Jared D. [Department of Earth and Environment, Boston University, 685 Commonwealth Ave., Boston, MA 02215 (United States)

    2014-12-01

    High resolution maps of urban vegetation and biomass are powerful tools for policy-makers and community groups seeking to reduce rates of urban runoff, moderate urban heat island effects, and mitigate the effects of greenhouse gas emissions. We developed a very high resolution map of urban tree biomass, assessed the scale sensitivities in biomass estimation, compared our results with lower resolution estimates, and explored the demographic relationships in biomass distribution across the City of Boston. We integrated remote sensing data (including LiDAR-based tree height estimates) and field-based observations to map canopy cover and aboveground tree carbon storage at ∼ 1 m spatial scale. Mean tree canopy cover was estimated to be 25.5 ± 1.5% and carbon storage was 355 Gg (28.8 Mg C ha{sup −1}) for the City of Boston. Tree biomass was highest in forest patches (110.7 Mg C ha{sup −1}), but residential (32.8 Mg C ha{sup −1}) and developed open (23.5 Mg C ha{sup −1}) land uses also contained relatively high carbon stocks. In contrast with previous studies, we did not find significant correlations between tree biomass and the demographic characteristics of Boston neighborhoods, including income, education, race, or population density. The proportion of households that rent was negatively correlated with urban tree biomass (R{sup 2} = 0.26, p = 0.04) and correlated with Priority Planting Index values (R{sup 2} = 0.55, p = 0.001), potentially reflecting differences in land management among rented and owner-occupied residential properties. We compared our very high resolution biomass map to lower resolution biomass products from other sources and found that those products consistently underestimated biomass within urban areas. This underestimation became more severe as spatial resolution decreased. This research demonstrates that 1) urban areas contain considerable tree carbon stocks; 2) canopy cover and biomass may not be related to the demographic

  17. Cooperation in carbon source degradation shapes spatial self-organization of microbial consortia on hydrated surfaces

    OpenAIRE

    Tecon, Robin; Or, Dani

    2017-01-01

    Mounting evidence suggests that natural microbial communities exhibit a high level of spatial organization at the micrometric scale that facilitate ecological interactions and support biogeochemical cycles. Microbial patterns are difficult to study definitively in natural environments due to complex biodiversity, observability and variable physicochemical factors. Here, we examine how trophic dependencies give rise to self-organized spatial patterns of a well-defined bacterial consortium grow...

  18. A novel source of biofertilizer from feather biomass for banana cultivation.

    Science.gov (United States)

    Gurav, Ranjit G; Jadhav, Jyoti P

    2013-07-01

    Feather waste is a promising protein biomass available as by-product from poultry processing was found to be rich in peptides, amino acids, and minerals like nitrogen, phosphorus, potassium, calcium, magnesium, iron, manganese, zinc, and copper. Soil and foliar application of these products, besides representing a sustainable solution to the problem of feather disposal, may also represent an effective strategy to tackle the environmental effluence. As a consequence, they were also found to be very attractive in elevating the protein, amino acids, reducing sugar, total chlorophyll, and proline content of plants. On the other side, fertilizing effect enhanced the antioxidant potential of banana fruit which was assessed using 2, 2-diphenyl-1-picrylhydrazyl, ferric reducing/antioxidant power, and N, N-dimethyl-p-phenylendiamine. This was associated with considerably higher antioxidant contents like total phenolics and flavonoids. Therefore, the application of this organic amendment could promote and improve the agro-ecosystem, human health; soil biological activities, and at the same time enhance the production of plant or products rich in bioactive substances.

  19. Topical report on sources and systems for aquatic plant biomass as an energy resource

    Energy Technology Data Exchange (ETDEWEB)

    Goldman, J.C.; Ryther, J.H.; Waaland, R.; Wilson, E.H.

    1977-10-21

    Background information is documented on the mass cultivation of aquatic plants and systems design that is available from the literature and through consultation with active research scientists and engineers. The biology of microalgae, macroalgae, and aquatic angiosperms is discussed in terms of morphology, life history, mode of existence, and ecological significance, as they relate to cultivation. The requirements for growth of these plants, which are outlined in the test, suggest that productivity rates are dependent primarily on the availability of light and nutrients. It is concluded that the systems should be run with an excess of nutrients and with light as the limiting factor. A historical review of the mass cultivation of aquatic plants describes the techniques used in commercial large-scale operations throughout the world and recent small-scale research efforts. This review presents information on the biomass yields that have been attained to date in various geographical locations with different plant species and culture conditions, emphasizing the contrast between high yields in small-scale operations and lower yields in large-scale operations.

  20. Biomass burning source characterization requirements in air quality models with and without data assimilation: challenges and opportunities

    Science.gov (United States)

    Hyer, E. J.; Zhang, J. L.; Reid, J. S.; Curtis, C. A.; Westphal, D. L.

    2007-12-01

    Quantitative models of the transport and evolution of atmospheric pollution have graduated from the laboratory to become a part of the operational activity of forecast centers. Scientists studying the composition and variability of the atmosphere put great efforts into developing methods for accurately specifying sources of pollution, including natural and anthropogenic biomass burning. These methods must be adapted for use in operational contexts, which impose additional strictures on input data and methods. First, only input data sources available in near real-time are suitable for use in operational applications. Second, operational applications must make use of redundant data sources whenever possible. This is a shift in philosophy: in a research context, the most accurate and complete data set will be used, whereas in an operational context, the system must be designed with maximum redundancy. The goal in an operational context is to produce, to the extent possible, consistent and timely output, given sometimes inconsistent inputs. The Naval Aerosol Analysis and Prediction System (NAAPS), a global operational aerosol analysis and forecast system, recently began incorporating assimilation of satellite-derived aerosol optical depth. Assimilation of satellite AOD retrievals has dramatically improved aerosol analyses and forecasts from this system. The use of aerosol data assimilation also changes the strategy for improving the smoke source function. The absolute magnitude of emissions events can be refined through feedback from the data assimilation system, both in real- time operations and in post-processing analysis of data assimilation results. In terms of the aerosol source functions, the largest gains in model performance are now to be gained by reducing data latency and minimizing missed detections. In this presentation, recent model development work on the Fire Locating and Monitoring of Burning Emissions (FLAMBE) system that provides smoke aerosol

  1. Biomass production and secretion of hydrolytic enzymes are influenced by the structural complexity of the nitrogen source in Fusarium oxysporum and Aspergillus nidulans.

    Science.gov (United States)

    da Silva, M C; Bertolini, M C; Ernandes, J R

    2001-01-01

    The structural complexity of the nitrogen sources strongly affects biomass production and secretion of hydrolytic enzymes in filamentous fungi. Fusarium oxysporum and Aspergillus nidulans were grown in media containing glucose or starch, and supplemented with a nitrogen source varying from a single ammonium salt (ammonium sulfate) to free amino acids (casamino acids), peptides (peptone) and protein (gelatin). In glucose, when the initial pH was adjusted to 5.0, for both microorganisms, higher biomass production occurred upon supplementation with a nitrogen source in the peptide form (peptone and gelatin). With a close to neutrality pH, biomass accumulation was lower only in the presence of the ammonium salt. When grown in starch, biomass accumulation and secretion of hydrolytic enzymes (amylolytic and proteolytic) by Fusarium also depended on the nature of the nitrogen supplement and the pH. When the initial pH was adjusted to 5.0, higher growth and higher amylolytic activities were detected in the media supplemented with peptone, gelatin and casamino acids. However, at pH 7.0, higher biomass accumulation and higher amylolytic activities were observed upon supplementation with peptone or gelatin. Ammonium sulfate and casamino acids induced a lower production of biomass, and a different level of amylolytic enzyme secretion: high in ammonium sulfate and low in casamino acids. Secretion of proteolytic activity was always higher in the media supplemented with peptone and gelatin. Aspergillus, when grown in starch, was not as dependent as Fusarium on the nature of nitrogen source or the pH. The results described in this work indicate that the metabolism of fungi is regulated not only by pH, but also by the level of structural complexity of the nitrogen source in correlation to the carbon source.

  2. Emerging Technologies for the Production of Renewable Liquid Transport Fuels from Biomass Sources Enriched in Plant Cell Walls

    Directory of Open Access Journals (Sweden)

    Hwei-Ting Tan

    2016-12-01

    Full Text Available Plant cell walls are composed predominantly of cellulose, a range of non-cellulosic polysaccharides and lignin. The walls account for a large proportion not only of crop residues such as wheat straw and sugarcane bagasse, but also of residues of the timber industry and specialist grasses and other plants being grown specifically for biofuel production. The polysaccharide components of plant cell walls have long been recognized as an extraordinarily large source of fermentable sugars that might be used for the production of bioethanol and other renewable liquid transport fuels. Estimates place annual plant cellulose production from captured light energy in the order of hundreds of billions of tonnes. Lignin is synthesised in the same order of magnitude and, as a very large polymer of phenylpropanoid residues, lignin is also an abundant, high energy macromolecule. However, one of the major functions of these cell wall constituents in plants is to provide the extreme tensile and compressive strengths that enable plants to resist the forces of gravity and a broad range of other mechanical forces. Over millions of years these wall constituents have evolved under natural selection to generate extremely tough and resilient biomaterials. The rapid degradation of these tough cell wall composites to fermentable sugars is therefore a difficult task and has significantly slowed the development of a viable lignocellulose-based biofuels industry. However, good progress has been made in overcoming this so-called recalcitrance of lignocellulosic feedstocks for the biofuels industry, through modifications to the lignocellulose itself, innovative pre-treatments of the biomass, improved enzymes and the development of superior yeasts and other microorganisms for the fermentation process. Nevertheless, it has been argued that bioethanol might not be the best or only biofuel that can be generated from lignocellulosic biomass sources and that hydrocarbons with

  3. Emerging Technologies for the Production of Renewable Liquid Transport Fuels from Biomass Sources Enriched in Plant Cell Walls

    Science.gov (United States)

    Tan, Hwei-Ting; Corbin, Kendall R.; Fincher, Geoffrey B.

    2016-01-01

    Plant cell walls are composed predominantly of cellulose, a range of non-cellulosic polysaccharides and lignin. The walls account for a large proportion not only of crop residues such as wheat straw and sugarcane bagasse, but also of residues of the timber industry and specialist grasses and other plants being grown specifically for biofuel production. The polysaccharide components of plant cell walls have long been recognized as an extraordinarily large source of fermentable sugars that might be used for the production of bioethanol and other renewable liquid transport fuels. Estimates place annual plant cellulose production from captured light energy in the order of hundreds of billions of tons. Lignin is synthesized in the same order of magnitude and, as a very large polymer of phenylpropanoid residues, lignin is also an abundant, high energy macromolecule. However, one of the major functions of these cell wall constituents in plants is to provide the extreme tensile and compressive strengths that enable plants to resist the forces of gravity and a broad range of other mechanical forces. Over millions of years these wall constituents have evolved under natural selection to generate extremely tough and resilient biomaterials. The rapid degradation of these tough cell wall composites to fermentable sugars is therefore a difficult task and has significantly slowed the development of a viable lignocellulose-based biofuels industry. However, good progress has been made in overcoming this so-called recalcitrance of lignocellulosic feedstocks for the biofuels industry, through modifications to the lignocellulose itself, innovative pre-treatments of the biomass, improved enzymes and the development of superior yeasts and other microorganisms for the fermentation process. Nevertheless, it has been argued that bioethanol might not be the best or only biofuel that can be generated from lignocellulosic biomass sources and that hydrocarbons with intrinsically higher energy

  4. Enhancing Management Tools: Molecular Genetic Tracking to Target Microbial Pollution Sources in South Florida Coral Reefs, Year 1 - CRCP project #1114

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Both coastal inlets and treated wastewater outfalls are recognized as major pathways for microbial contaminants from Land-Based Sources of Pollution (LBSP) to enter...

  5. Cooperation in carbon source degradation shapes spatial self-organization of microbial consortia on hydrated surfaces.

    Science.gov (United States)

    Tecon, Robin; Or, Dani

    2017-03-06

    Mounting evidence suggests that natural microbial communities exhibit a high level of spatial organization at the micrometric scale that facilitate ecological interactions and support biogeochemical cycles. Microbial patterns are difficult to study definitively in natural environments due to complex biodiversity, observability and variable physicochemical factors. Here, we examine how trophic dependencies give rise to self-organized spatial patterns of a well-defined bacterial consortium grown on hydrated surfaces. The model consortium consisted of two Pseudomonas putida mutant strains that can fully degrade the aromatic hydrocarbon toluene. We demonstrated that obligate cooperation in toluene degradation (cooperative mutualism) favored convergence of 1:1 partner ratio and strong intermixing at the microscale (10-100 μm). In contrast, competition for benzoate, a compound degraded independently by both strains, led to distinct segregation patterns. Emergence of a persistent spatial pattern has been predicted for surface attached microbial activity in liquid films that mediate diffusive exchanges while permitting limited cell movement (colony expansion). This study of a simple microbial consortium offers mechanistic glimpses into the rules governing the assembly and functioning of complex sessile communities, and points to general principles of spatial organization with potential applications for natural and engineered microbial systems.

  6. Carbon isotopes of dissolved inorganic carbon reflect utilization of different carbon sources by microbial communities in two limestone aquifer assemblages

    Directory of Open Access Journals (Sweden)

    M. E. Nowak

    2017-08-01

    Full Text Available Isotopes of dissolved inorganic carbon (DIC are used to indicate both transit times and biogeochemical evolution of groundwaters. These signals can be complicated in carbonate aquifers, as both abiotic (i.e., carbonate equilibria and biotic factors influence the δ13C and 14C of DIC. We applied a novel graphical method for tracking changes in the δ13C and 14C of DIC in two distinct aquifer complexes identified in the Hainich Critical Zone Exploratory (CZE, a platform to study how water transport links surface and shallow groundwaters in limestone and marlstone rocks in central Germany. For more quantitative estimates of contributions of different biotic and abiotic carbon sources to the DIC pool, we used the NETPATH geochemical modeling program, which accounts for changes in dissolved ions in addition to C isotopes. Although water residence times in the Hainich CZE aquifers based on hydrogeology are relatively short (years or less, DIC isotopes in the shallow, mostly anoxic, aquifer assemblage (HTU were depleted in 14C compared to a deeper, oxic, aquifer complex (HTL. Carbon isotopes and chemical changes in the deeper HTL wells could be explained by interaction of recharge waters equilibrated with post-bomb 14C sources with carbonates. However, oxygen depletion and δ13C and 14C values of DIC below those expected from the processes of carbonate equilibrium alone indicate considerably different biogeochemical evolution of waters in the upper aquifer assemblage (HTU wells. Changes in 14C and 13C in the upper aquifer complexes result from a number of biotic and abiotic processes, including oxidation of 14C-depleted OM derived from recycled microbial carbon and sedimentary organic matter as well as water–rock interactions. The microbial pathways inferred from DIC isotope shifts and changes in water chemistry in the HTU wells were supported by comparison with in situ microbial community structure based on 16S rRNA analyses. Our findings

  7. Biomasa microbiana y actividad ureasa del suelo en una pradera permanente pastoreada de Chile Soil microbial biomass and urease activity in a grazed permanent pasture from Chile

    Directory of Open Access Journals (Sweden)

    Pedro Antonio Núñez Ramos

    2012-12-01

    Full Text Available En los sistemas de pasturas; la productividad de la pradera puede estar influenciada por el manejo; debido a su impacto sobre los microorganismos del suelo y el reciclaje de nutrientes. El objetivo de este trabajo fue evaluar la biomasa microbiana (BM del suelo asociada al nitrógeno (BMN; carbono (BMC y la actividad ureasa (AU en una pradera permanente del sur de Chile. Entre la primavera de 2005 y el invierno de 2006 fueron evaluados dos sistemas de pastoreo: pastoreo intenso (PI; pastoreo suave (PS y un tratamiento control (C. El diseño fue en bloques al azar con tres repeticiones. En relación a los valores promedios medidos de las variables en pre y post pastoreo; se produjo un incremento en los contenidos de CB en un 21,8 y 8,6% para PI y PS; mientras que en el control fue sólo de 1,9%. Los contenidos de NB también fueron incrementados en un 16 y 19% para PI y PS; respectivamente en comparación con el control (4%. La actividad ureasa aumentó en 13 y 27% para PI y PS; respectivamente en comparación con el control (5%. El pastoreo; produce un flujo más alto de residuos orgánicos en el suelo; lo que estimula la actividad de la biomasa microbiana y; por tanto; aumentó la AU y los contenidos de CB y NB. Esto sugiere que; en los sistemas de pastoreo; se mejora la fertilidad biológica de los suelos y la disponibilidad de nutrientes.In pasture systems, management practices can affect pasture productivity differently due to their impact on soil microorganisms and nutrient cycling. The objective of this study was to evaluate the relationship between soil microbial biomass (MB nitrogen (MBN, carbon (MBC and urease activity (UA in a permanent pasture in southern Chile. Two grazing systems were evaluated between spring 2005 and winter 2006 : heavy grazing (HG, light grazing (LG and a control treatment (C. Treatments were arranged in a randomized block design with three replications. Concerning the average values of the variables measured at

  8. Biomassa microbiana, em um Argissolo Vermelho, em diferentes coberturas vegetais, em área cultivada com mandioca = Microbial biomass on an Oxisol in cassava using different cover species

    Directory of Open Access Journals (Sweden)

    Fábio Martins Mercante

    2008-10-01

    Full Text Available Objetivou-se avaliar a influência de cultivos de mandioca, em diferentes sistemas de manejo sobre a biomassa microbiana de solo, sua atividade e índices derivados. O estudo foi conduzido no Município de Glória de Dourados, Estado do Mato Grosso doSul, em Argissolo Vermelho, de textura arenosa, em sistema de preparo convencional, plantio direto, sobre resíduos culturais de mucuna, sorgo e milheto, além de sistema com vegetação nativa, usado como referencial para comparação. As avaliações foram realizadasem seis épocas distintas: maio/2003, junho/2003, novembro/2003, abril/2004, agosto/2004 e novembro/2004. A presença ou ausência de resíduos vegetais influenciou diretamente a microbiota do solo, indicando que o uso de plantas de cobertura, no cultivo de mandioca,favorece a melhoria da qualidade do solo, representando alternativa promissora para melhor manejo desta cultura.The objective of this work was to evaluate the effect of cassava cultivation under different management practices on soil microbial biomass, its activity and its derived indexes. The field experiment was carried out in Glória de Dourados, Mato Grosso do Sul State, Brazil, in a sandy soil (Oxisol, under conventional drilling, no-tillage system under Estilozobium pruriens, Sorghum bicolor and Pennisetum glaucum mulching, compared to the native vegetation system. Evaluations were done in May/2003, June/2003, November/2003,April/2004 and November/2004. Soil microbiota was directly influenced by the presence or absence of vegetable residues, indicating that the use of covering plants in cassava cultivation favors the improvement of soil quality, representing a promising alternative for better management practices of this cultivation.

  9. [Soil soluble organic matter, microbial biomass, and enzyme activities in forest plantations in degraded red soil region of Jiangxi Province, China].

    Science.gov (United States)

    Jiang, Yu-mei; Chen, Cheng-long; Xu, Zhi-hong; Liu, Yuan-qiu; Ouyang, Jing; Wang, Fang

    2010-09-01

    Taking the adjacent 18-year-old pure Pinus massoniana pure forest (I), P. massoniana, Liquidamber fomosana, and Schima superba mixed forest (II), S. superba pure forest (III), L. fomosana (IV) pure forest, and natural restoration fallow land (CK) in Taihe County of Jiangxi Province as test sites, a comparative study was made on their soil soluble organic carbon (SOC) and nitrogen (SON), soil microbial biomass C (MBC) and N (MBN), and soil urease and asparaginase activities. In 0-10 cm soil layer, the pool sizes of SOC, SON, MBC, and MBN at test sites ranged in 354-1007 mg x kg(-1), 24-73 mg x kg(-1), 203-488 mg x kg(-1), and 24-65 mg x kg(-1), and the soil urease and asparaginase activities were 95-133 mg x kg(-1) x d(-1) and 58-113 mg x kg(-1) x d(-1), respectively. There were significant differences in the pool sizes of SOC, SON, MBC, and MBN and the asparaginase activity among the test sites, but no significant difference was observed in the urease activity. The pool sizes of SOC and SON were in the order of IV > CK > III > I > II, those of MBC and MBN were in the order of CK > IV > III > I > II, and asparaginase activity followed the order of IV > CK > III > II > I. With the increase of soil depth, the pool sizes of SOC, SON, MBC, and MBN and the activities of soil asparaginase and urease decreased. In 0-20 cm soil layer, the SOC, SON, MBC, MBN, total C, and total N were highly correlated with each other, soil asparaginase activity was highly correlated with SOC, SON, TSN, total C, total N, MBC, and MBN, and soil urease activity was highly correlated with SON, TSN, total C, MBC and MBN.

  10. Effects of different sources of protein on digestive characteristics, microbial efficiency, and nutrient flow in dairy goats

    Directory of Open Access Journals (Sweden)

    Nivea Regina de Oliveira Felisberto

    2011-10-01

    Full Text Available Diets formulated with protein sources presenting different resistance to ruminal degradation were compared by evaluating ruminal parameters, production and microbial efficiency and nutrients flow to the omasum in goats. Eight rumen cannulated non-lactating, non-pregnant goats were distributed in a 4 × 4 Latin square design with two replicates. Treatments consisted of four diets where different sources of plant protein accounted for the major protein source named soybean meal, source of higher ruminal degradability, and three other sources of higher resistance of degradation: roasted soybean, corn gluten meal, and cottonseed cake. Amounts of rumen protein were similar among rations; however, flows of dry matter, protein and non-fiber carbohydrate to omasum were higher for diets with protein source with reduced rumen degradation rate. Higher values of rumen ammonia were obtained by using ration with soybean meal as major source of protein. Higher values of pH were obtained for rations with roasted soybean e cottonseed cake. Regarding kinetic of transit, similar values were found among rations. Diets with protein sources presenting reduced ruminal degradation increase nutrients flow to the omasum in goats and alter digestive parameters such as pH and ammonia without compromising bacteria growth and efficiency, which grants their use for dairy goats with similar efficiency to rations using more degradable sources of protein.

  11. Effects of grain source, grain processing, and protein degradability on rumen kinetics and microbial protein synthesis in Boer kids.

    Science.gov (United States)

    Brassard, M-E; Chouinard, P Y; Berthiaume, R; Tremblay, G F; Gervais, R; Martineau, R; Cinq-Mars, D

    2015-11-01

    Microbial protein synthesis in the rumen would be optimized when dietary carbohydrates and proteins have synchronized rates and extent of degradation. The aim of this study was to evaluate the effect of varying ruminal degradation rate of energy and nitrogen sources on intake, nitrogen balance, microbial protein yield, and kinetics of nutrients in the rumen of growing kids. Eight Boer goats (38.2 ± 3.0 kg) were used. The treatments were arranged in a split-plot Latin square design with grain sources (barley or corn) forming the main plots (squares). Grain processing methods and levels of protein degradability formed the subplots in a 2 × 2 factorial arrangement for a total of 8 dietary treatments. The grain processing method was rolling for barley and cracking for corn. Levels of protein degradability were obtained by feeding untreated soybean meal (SBM) or heat-treated soybean meal (HSBM). Each experimental period lasted 21 d, consisting of a 10-d adaptation period, a 7-d digestibility determination period, and a 4-d rumen evacuation and sampling period. Kids fed with corn had higher purine derivatives (PD) excretion when coupled with SBM compared with HSBM and the opposite occurred with barley-fed kids ( ≤ 0.01). Unprocessed grain offered with SBM led to higher PD excretion than with HSBM whereas protein degradability had no effect when processed grain was fed ( ≤ 0.03). Results of the current experiment with high-concentrate diets showed that microbial N synthesis could be maximized in goat kids by combining slowly fermented grains (corn or unprocessed grains) with a highly degradable protein supplement (SBM). With barley, a more rapidly fermented grain, a greater microbial N synthesis was observed when supplementing a low-degradable protein (HSBM).

  12. Ionic Liquids in Biomass Processing

    Science.gov (United States)

    Tan, Suzie Su Yin; Macfarlane, Douglas R.

    Ionic liquids have been studied for their special solvent properties in a wide range of processes, including reactions involving carbohydrates such as cellulose and glucose. Biomass is a widely available and renewable resource that is likely to become an economically viable source of starting materials for chemical and fuel production, especially with the price of petroleum set to increase as supplies are diminished. Biopolymers such as cellulose, hemicellulose and lignin may be converted to useful products, either by direct functionalisation of the polymers or depolymerisation to monomers, followed by microbial or chemical conversion to useful chemicals. Major barriers to the effective conversion of biomass currently include the high crystallinity of cellulose, high reactivity of carbohydrates and lignin, insolubility of cellulose in conventional solvents, as well as heterogeneity in the native lignocellulosic materials and in lignin itself. This combination of factors often results in highly heterogeneous depolymerisation products, which make efficient separation difficult. Thus the extraction, depolymerisation and conversion of biopolymers will require novel reaction systems in order to be both economically attractive and environmentally benign. The solubility of biopolymers in ionic liquids is a major advantage of their use, allowing homogeneous reaction conditions, and this has stimulated a growing research effort in this field. This review examines current research involving the use of ionic liquids in biomass reactions, with perspectives on how it relates to green chemistry, economic viability, and conventional biomass processes.

  13. FATTY ACID STABLE ISOTOPE INDICATORS OF MICROBIAL CARBON SOURCE IN TROPICAL SOILS

    Science.gov (United States)

    The soil microbial community plays an important role in tropical ecosystem functioning because of its importance in the soil organic matter (SOM) cycle. We have measured the stable carbon isotopic ratio (delta13C) of individual phospholipid fatty acids (PLFAs) in a variety of tr...

  14. Microbial water quality of treated water and raw water sources in the ...

    African Journals Online (AJOL)

    2015-10-05

    Oct 5, 2015 ... assessed for microbial quality using hydrogen sulphide test and .... existence of the same problem in other cities and towns in ... (2011). Urine jars were placed in the Panasonic ... were assembled and stored away from direct sunlight, at room .... view was conducted with the Drug and Toxicology Information.

  15. Microbial water quality of treated water and raw water sources in the ...

    African Journals Online (AJOL)

    Microbial water quality is an essential aspect in the provision of potable water for domestic use. The provision of adequate amounts of safe water for domestic purposes has become difficult for most municipalities mandated to do so in Zimbabwe. Morton-Jaffray Treatment Plant supplies potable water to Harare City and ...

  16. Improved biomass utilization through the use of nuclear techniques

    International Nuclear Information System (INIS)

    1988-10-01

    Biomass is a major by-product resource of agriculture and food manufacturing, but it is under-utilized as a source of food, fibre, and chemicals. Nuclear techniques provide unique tools for studies of the capabilities of micro-organisms in methane digestor operation and in the transformation of lignocellulosic materials to useful products. Nuclear techniques have also been effectively employed as mutagenic agents in the preparation of more efficient microbial strains for the conversion of biomass. This report reviews the variety and diversity of such applications with focus on the development of microbial processes to utilize agricultural wastes and by-products. The value of nuclear techniques is manifestly demonstrated in the production of efficient microbial mutant strains, in the tracing of metabolic pathways, in the monitoring of lignin degradation and also of fermenter operation. Refs, figs and tabs

  17. Cr(Vi) reduction capacity of activated sludge as affected by nitrogen and carbon sources, microbial acclimation and cell multiplication

    International Nuclear Information System (INIS)

    Ferro Orozco, A.M.; Contreras, E.M.; Zaritzky, N.E.

    2010-01-01

    The objectives of the present work were: (i) to analyze the capacity of activated sludge to reduce hexavalent chromium using different carbon sources as electron donors in batch reactors, (ii) to determine the relationship between biomass growth and the amount of Cr(VI) reduced considering the effect of the nitrogen to carbon source ratio, and (iii) to determine the effect of the Cr(VI) acclimation stage on the performance of the biological chromium reduction assessing the stability of the Cr(VI) reduction capacity of the activated sludge. The highest specific Cr(VI) removal rate (q Cr ) was attained with cheese whey or lactose as electron donors decreasing in the following order: cheese whey ∼ lactose > glucose > citrate > acetate. Batch assays with different nitrogen to carbon source ratio demonstrated that biological Cr(VI) reduction is associated to the cell multiplication phase; as a result, maximum Cr(VI) removal rates occur when there is no substrate limitation. The biomass can be acclimated to the presence of Cr(VI) and generate new cells that maintain the ability to reduce chromate. Therefore, the activated sludge process could be applied to a continuous Cr(VI) removal process.

  18. Fibrous Agricultural Biomass as a Potential Source for Bioconversion to Vanillic Acid

    Directory of Open Access Journals (Sweden)

    Pei-Ling Tang

    2014-01-01

    Full Text Available This study was conducted to assess the potential of six fibrous agricultural residues, namely, oil palm empty fruit bunch fiber (OPEFBF, coconut coir fiber (CCF, pineapple peel (PP, pineapple crown leaves (PCL, kenaf bast fiber (KBF, and kenaf core fiber (KCF, as a source of ferulic acid and phenolic compounds for bioconversion into vanillic acid. The raw samples were pretreated with organosolv (NaOH-glycerol and alkaline treatment (NaOH, to produce phenol-rich black liquor. The finding showed that the highest amount of phenolic compounds and ferulic acid was produced from CCF and PP, respectively. This study also found that organosolv treatment was the superior method for phenolic compound extraction, whereas alkaline treatment was the selective method for lignin extraction. Vanillic acid production by Aspergillus niger I-1472 was only observed when the fermentation broth was fed with liquors from PP and PCL, possibly due to the higher levels of ferulic acid in those samples.

  19. Mapping carbon storage in urban trees with multi-source remote sensing data: relationships between biomass, land use, and demographics in Boston neighborhoods.

    Science.gov (United States)

    Raciti, Steve M; Hutyra, Lucy R; Newell, Jared D

    2014-12-01

    High resolution maps of urban vegetation and biomass are powerful tools for policy-makers and community groups seeking to reduce rates of urban runoff, moderate urban heat island effects, and mitigate the effects of greenhouse gas emissions. We developed a very high resolution map of urban tree biomass, assessed the scale sensitivities in biomass estimation, compared our results with lower resolution estimates, and explored the demographic relationships in biomass distribution across the City of Boston. We integrated remote sensing data (including LiDAR-based tree height estimates) and field-based observations to map canopy cover and aboveground tree carbon storage at ~1m spatial scale. Mean tree canopy cover was estimated to be 25.5±1.5% and carbon storage was 355Gg (28.8MgCha(-1)) for the City of Boston. Tree biomass was highest in forest patches (110.7MgCha(-1)), but residential (32.8MgCha(-1)) and developed open (23.5MgCha(-1)) land uses also contained relatively high carbon stocks. In contrast with previous studies, we did not find significant correlations between tree biomass and the demographic characteristics of Boston neighborhoods, including income, education, race, or population density. The proportion of households that rent was negatively correlated with urban tree biomass (R(2)=0.26, p=0.04) and correlated with Priority Planting Index values (R(2)=0.55, p=0.001), potentially reflecting differences in land management among rented and owner-occupied residential properties. We compared our very high resolution biomass map to lower resolution biomass products from other sources and found that those products consistently underestimated biomass within urban areas. This underestimation became more severe as spatial resolution decreased. This research demonstrates that 1) urban areas contain considerable tree carbon stocks; 2) canopy cover and biomass may not be related to the demographic characteristics of Boston neighborhoods; and 3) that recent advances

  20. Mapping Carbon Storage in Urban Trees with Multi-source Remote Sensing Data: Relationships between Biomass, Land Use, and Demographics in Boston Neighborhoods

    Science.gov (United States)

    Raciti, S. M.; Hutyra, L.

    2014-12-01

    High resolution maps of urban vegetation and biomass are powerful tools for policy-makers and community groups seeking to reduce rates of urban runoff, moderate urban heat island effects, and mitigate the effects of greenhouse gas emissions. We develop a very high resolution map of urban tree biomass, assess the scale sensitivities in biomass estimation, compare our results with lower resolution estimates, and explore the demographic relationships in biomass distribution across the City of Boston. We integrated remote sensing data (including LiDAR-based tree height estimates) and field-based observations to map canopy cover and aboveground tree carbon storage at ~1 m spatial scale. Mean tree canopy cover was estimated to be 25.5±1.5% and carbon storage was 355 Gg (28.8 Mg C ha-1) for the City of Boston. Tree biomass was highest in forest patches (110.7 Mg C ha-1), but residential (32.8 Mg C ha-1) and developed open (23.5 Mg C ha-1) land uses also contained relatively high carbon stocks. In contrast with previous studies, we did not find significant correlations between tree biomass and the demographic characteristics of Boston neighborhoods, including income, education, race, or population density. The proportion of households that rent was negatively correlated with urban tree biomass (R2=0.26, p=0.04) and correlated with Priority Planting Index values (R2=0.55, p=0.001), potentially reflecting differences in land management among rented and owner-occupied residential properties. We compared our very high resolution biomass map to lower resolution biomass products from other sources and found that those products consistently underestimated biomass within urban areas. This underestimation became more severe as spatial resolution decreased. This research demonstrates that 1) urban areas contain considerable tree carbon stocks; 2) canopy cover and biomass may not be related to the demographic characteristics of Boston neighborhoods; and 3) that recent advances in

  1. Analytical evaluation of different carbon sources and growth stimulators on the biomass and lipid production of Chlorella vulgaris – Implications for biofuels

    International Nuclear Information System (INIS)

    Josephine, A.; Niveditha, C.; Radhika, A.; Shali, A. Brindha; Kumar, T.S.; Dharani, G.; Kirubagaran, R.

    2015-01-01

    The key challenges in lipid production from marine microalgae include the selection of appropriate strain, optimization of the culture conditions and enhancement of biolipid yield. This study is aimed at evaluating the optimal harvest time and effect of chlorella growth factor (CGF) extract, carbon sources and phytohormones on the biomass and lipid production in Chlorella vulgaris. CGF, extracted using hot water from Chlorella has been reported to possess various medicinal properties. However, in the present study, for the first time in C. vulgaris, CGF was found as a best growth stimulator by enhancing the biomass level (1.208 kg m −3 ) significantly on day 5. Gibberellin and citrate augmented the biomass by 0.935 kg m −3 and 1.025 kg m −3 . Combination of CGF and phytohormones were more effective than CGF and carbon sources. Analysis of fatty acid methyl esters indicated that the ratio of saturated to unsaturated fatty acids is higher in cytokinin, abscisic acid and CGF, and are also rich in short chain carbon atoms, ideal criteria for biodiesel. Nitrogen starvation favoured synthesis of more unsaturated fatty acids than saturated. This study shows that CGF enhances the biomass and lipid significantly and thus can be used for large scale biomass production. - Highlights: • Optimization studies revealed 7th day to be the ideal period for harvesting Chlorella vulgaris. • Chlorella growth factor extract acted as a chief growth promoting factor of C. vulgaris. • Chlorella growth factor with carbon sources or phytohormones was not effective than chlorella growth factor extract alone. • Cytokinin treatment increased saturated fatty acids level, although the biomass production was not significant

  2. Intercropping Between Achillea millefolium L. and Rosmarinus officinalis L. and its effects on essential oil yield, biomass and anti-microbial activity

    OpenAIRE

    Arashiro, Munique Polito; Centro Universitário de Maringá - CESUMAR; Ziroldo, Débora Fernanda; Centro Universitário de Maringá - CESUMAR; Yamaguchi, Mirian Ueda; Centro Universitário de Maringá - CESUMAR; Sartor, Claudenice Francisca Providelo; Centro Universitário de Maringá - CESUMAR; Patroni, Sandra Sanches; Centro Universitário de Maringá - CESUMAR; Oliveira, Pérsio Sandir D'; EMBRAPA; Cortez, Lúcia Elaine Elaine Ranieri; Centro Universitário de Maringá - CESUMAR

    2011-01-01

    The rosemary (Rosmarinus officinalis) and the yarrow (Achillea millefolium) are medicinal aromatic herbs and produce essential oil. Current experiment evaluated the effect of intercropping between two species in biomass and essential oil yield and the antimicrobial activity of the essential oil of rosemary. After the plants’ culture and harvest, the biomass and the essential oil yields of the dry leaves and flowers were obtained by steam water distillation. Data of biomass and essential oil y...

  3. Effects of Seasonal and Perennial Grazing on Soil Fauna Community and Microbial Biomass Carbon in the Subalpine Meadows of Yunnan, Southwest China

    Institute of Scientific and Technical Information of China (English)

    LIU Shengjie; YANG Xiaodong; Anthony R.IVES; FENG Zhili; SHA Liqing

    2017-01-01

    Grazing and over-grazing may drive changes in the diversity and functioning of below-ground meadow ecosystems.A field soil survey was conducted to compare microbial biomass carbon (Cmin) and soil fauna communities in the two main grassland management systems in subalpine regions of Yunnan Province,China:perennial grazing currently practiced due to increasing herd sizes and traditional seasonal grazing.A three-year exclosure experiment was then conducted to further compare the effects of different grazing practices,including treatments of no mowing,perennial grazing (NM + G),mowing followed by seasonal grazing (M + G),mowing and no grazing (M + NG),and no mowing or grazing (NM + NG).The comparative survey result revealed that Cmin and total density of soil fauna were significantly lower at a perennially grazed site than at a seasonally grazed site.The experiment results showed that in comparison to non-grazing treatments (M + NG and NM + NG),grazing (NM + G and M + G) reduced total fauna density (by 150 individuals m-2) and the number of taxonomic groups present (by 0.32 taxa m-2).Mowing decreased Cmin (by 0.31 mg g-1).Furthermore,the NM + G treatment (perennial grazing) had the lowest density of Collembola (16.24 individuals m-2),one of the two most common taxonomic groups,although other taxonomic groups responded differently to the treatments.Treatment effects on soil fauna were consistent with those on above-ground grasses,in which C:N ratios were greatly reduced by grazing,with this effect being the greatest for the NM + G treatment.In contrast,different grazing treatments had little effect on C:N ratio of soil.Furthermore,the traditional grazing method (mowing followed by seasonal grazing) may have less severe effects on some taxonomic groups than perennial grazing.Therefore,an appropriate management should aim to protect soil fauna and microbes in this area from over-grazing and against further degradation.

  4. Evaluation of microbial biomass C and N content of the soils cultivated with vetch (Vicia sativa L. and alfalfa (Medicago sativa L.

    Directory of Open Access Journals (Sweden)

    İlyas Bolat

    2016-01-01

    Full Text Available Legume forage crops have the ability of retaining free nitrogen in the air through symbiotic Rhizobium bacteria found in their roots. Additionally, microbial biomass (MB–an essential living component of soil and a significant factor influencing plant nutrient dynamics–is considered to be accurate indicator of soil’s biological condition. Given the aforementioned aspects, soil MB C (Cmic and MB N (Nmic of different legume forage crops were investigated in this study. Soil samples were taken in order to identify certain physical and chemical characteristics of the soil using volume cylinders (0 – 6.5 cm depth from Vicia sativa L. (VSP and Medicago sativa L. planted (MSP areas. To determine the Cmic and Nmic contents, topsoil samples were also taken from 0 – 6.5 cm depth. Cmic and Nmic contents were identified using chloroform – fumigation – extraction method. There was no statistical significance for particle density, bulk density, electrical conductivity, CaCO3 %, and decomposition ratio (Corg/Ntotal of the VSP and MSP soil (P > 0.05. However, some other soil characteristics such as temperature, porosity, sand, silt and clay contents, pH, organic C and total N differed significantly (P < 0.05. Compared to VSP soil, the Cmic contents were determined to be 27 % higher (P < 0.05 in MSP soil. In VSP soil, the soil Nmic content ranged from 83.38 µg g-1 to 124.67 µg g-1, while it ranged from 91.62 µg g-1 to 187.07 µg g-1 in MSP soil. The Nmic content of the MSP soil was observed to be approximately 35 % higher than VSP soil, and a statistically significant difference (P < 0.05 was noticed between the two. Moreover, a significant positive correlation was found not only between the Cmic and organic C contents (r = 0.667; P < 0.05 but also between the Nmic and total N contents of MSP and VSP soil (r = 0.881; P < 0.01. The results of the study revealed that soil Cmic and Nmic values differ as the types of planted legume forage crops

  5. The functional potential of microbial communities in hydraulic fracturing source water and produced water from natural gas extraction characterized by metagenomic sequencing.

    Directory of Open Access Journals (Sweden)

    Arvind Murali Mohan

    Full Text Available Microbial activity in produced water from hydraulic fracturing operations can lead to undesired environmental impacts and increase gas production costs. However, the metabolic profile of these microbial communities is not well understood. Here, for the first time, we present results from a shotgun metagenome of microbial communities in both hydraulic fracturing source water and wastewater produced by hydraulic fracturing. Taxonomic analyses showed an increase in anaerobic/facultative anaerobic classes related to Clostridia, Gammaproteobacteria, Bacteroidia and Epsilonproteobacteria in produced water as compared to predominantly aerobic Alphaproteobacteria in the fracturing source water. The metabolic profile revealed a relative increase in genes responsible for carbohydrate metabolism, respiration, sporulation and dormancy, iron acquisition and metabolism, stress response and sulfur metabolism in the produced water samples. These results suggest that microbial communities in produced water have an increased genetic ability to handle stress, which has significant implications for produced water management, such as disinfection.

  6. Woody biomass: Niche position as a source of sustainable renewable chemicals and energy and kinetics of hot-water extraction/hydrolysis.

    Science.gov (United States)

    Liu, Shijie

    2010-01-01

    The conversion of biomass to chemicals and energy is imperative to sustaining our way of life as known to us today. Fossil chemical and energy sources are traditionally regarded as wastes from a distant past. Petroleum, natural gas, and coal are not being regenerated in a sustainable manner. However, biomass sources such as algae, grasses, bushes and forests are continuously being replenished. Woody biomass represents the most abundant and available biomass source. Woody biomass is a reliably sustainable source of chemicals and energy that could be replenished at a rate consistent with our needs. The biorefinery is a concept describing the collection of processes used to convert biomass to chemicals and energy. Woody biomass presents more challenges than cereal grains for conversion to platform chemicals due to its stereochemical structures. Woody biomass can be thought of as comprised of at least four components: extractives, hemicellulose, lignin and cellulose. Each of these four components has a different degree of resistance to chemical, thermal and biological degradation. The biorefinery concept proposed at ESF (State University of New York - College of Environmental Science and Forestry) aims at incremental sequential deconstruction, fractionation/conversion of woody biomass to achieve efficient separation of major components. The emphasis of this work is on the kinetics of hot-water extraction, filling the gap in the fundamental understanding, linking engineering developments, and completing the first step in the biorefinery processes. This first step removes extractives and hemicellulose fractions from woody biomass. While extractives and hemicellulose are largely removed in the extraction liquor, cellulose and lignin largely remain in the residual woody structure. Xylo-oligomers and acetic acid in the extract are the major components having the greatest potential value for development. Extraction/hydrolysis involves at least 16 general reactions that could

  7. Differential Decay of Cattle-associated Fecal Indicator Bacteria and Microbial Source Tracking Markers in Fresh and Marine Water (ASM 2017 Presentation)

    Science.gov (United States)

    Background: Fecal indicator bacteria (FIB) have a long history of use in the assessment of the microbial quality of recreational waters. However, quantification of FIB provides no information about the pollution source(s) and relatively little is known about their fate in the amb...

  8. Oil palm biomass utilization as an energy source and its possibility use for polygeneration scenarios in Langsa City, Aceh Province, Indonesia

    Science.gov (United States)

    Hani, M. R.; Mahidin, M.; Husin, H.; Hamdani, H.; Khairil, K.

    2018-03-01

    This article deals with the discussion on the recent status of oil palm biomass utilization as an energy source and its possibility use for polygeneration system. The discussion focused only on the energy viewpoint. At this point, many projects and research have been developed in order to utilize the oil palm biomass to meet the energy demand of industries and communities, especially in the largest producing countries: Indonesia and Malaysia; and a few in Thailand, Africa, Latin America and Europe. Through the simulation work in the case study, it is evident that the government of Langsa City can fulfill the fresh water to their community and electricity to Langsa Harbor only by using EFB and PKS from one POM with the generated power of 12 MW, while the desalination plant consumes about 7 MW of electricity. If all potency of biomass from all POMs in Aceh Timur and Aceh Tamiang, without the combination of other primary energy sources is used, Langsa City might earn surplus of energy. The use of the oil palm biomass for polygeneration scenarios is possible and feasible from the technical point of view.

  9. Internalisation of microbes in vegetables: microbial load of Ghanaian vegetables and the relationship with different water sources of irrigation.

    Science.gov (United States)

    Donkor, Eric S; Lanyo, R; Kayang, Boniface B; Quaye, Jonathan; Edoh, Dominic A

    2010-09-01

    The occurrence of pathogens in the internal parts of vegetables is usually associated with irrigation water or contaminated soil and could pose risk to consumers as the internalised pathogens are unaffected by external washing. This study was carried out to assess the rate of internalisation of microbes in common Ghanaian vegetables. Standard microbiological methods were employed in microbial enumeration of vegetables collected at the market and farm levels, as well as irrigation water and soil samples. The overall mean counts of vegetables were 4.0 x 10(3) cfu g(-1); 8.1 x 10(2) cfu g(-1); 2.0 x 10(2) cfu g(-1); 3.5 x 10(2) cfu g(-1) for total bacteria, coliform counts, faecal coliform counts and yeast counts, respectively. The rate of internalisation of coliforms in vegetables irrigated with stream/well water was 2.7 times higher than those irrigated with pipe water. The mean coliform counts (4.7 x 10(7) cfu g(-1)) and faecal coliform counts (1.8 x 10(6) cfu g(-1)) of soil samples were similar to those of stream water suggesting both sources exerted similar contamination rates on the vegetables. Generally, there were no significant variations between the rates of internalisation of microbes at the market and farm levels at p vegetables mainly occurred at the farm level. The study has shown that microbial contamination of vegetables in Ghana is not limited to the external surface, but internal vegetable parts could harbour high microbial loads and pose risk to consumers. Safety practices associated with the commodity should therefore not be limited to external washing only. There is the additional need of heating vegetables to eliminate microbes both externally and internally before consumption.

  10. Compost as a source of microbial isolates for the bioremediation of heavy metals: In vitro selection

    International Nuclear Information System (INIS)

    Vargas-García, María del Carmen; López, María José; Suárez-Estrella, Francisca; Moreno, Joaquín

    2012-01-01

    Heavy metal pollution has become a major environmental concern nowadays and the bioremediation of polluted habitats is an increasingly popular strategy due to both its efficiency and safety. A screening and selection protocol based on different composting processes was designed in order to isolate heavy metal-resistant microorganisms. A collection of 51 microorganisms was obtained and most of them showed the capability to tolerate heavy metals in multi-polluted aqueous systems (Cd(II), Cr(VI), Ni, Pb, Zn(II)), as well as to remove them. The highest detoxification ratios were observed for Pb. Some of the isolates detoxifying more than a 90% of this metal, while the other metals were removed in a range between 20% and 60%. The best isolates (Graphium putredinis, Fusarium solani, Fusarium sp. and Penicillium chrysogenum) were further assayed in order to determine the predominant removal mechanism and the potential use of their dead biomass as a biosorbent. Intracellular accumulation was the prevalent mechanism for most isolates and metals, with the exception of Ni. In this case, the proportion removed by extracellular adsorption was similar or even higher than that removed by intracellular accumulation. Thus, the efficiency of living cells was higher than that of dead biomass except in the case of Ni. - Highlights: ► Composting is a good reservoir for the isolation of HM-resistant microorganisms. ► Pb was the most removed heavy metal in multi-polluted aqueous systems. ► Intracellular accumulation was the predominant mechanism for heavy metal removal. ► Graphium putredinis, which detoxifies organic pollutants, was the most efficient isolate.

  11. Compost as a source of microbial isolates for the bioremediation of heavy metals: In vitro selection

    Energy Technology Data Exchange (ETDEWEB)

    Vargas-Garcia, Maria del Carmen, E-mail: mcvargas@ual.es; Lopez, Maria Jose, E-mail: mllopez@ual.es; Suarez-Estrella, Francisca, E-mail: fsuarez@ual.es; Moreno, Joaquin, E-mail: jcasco@ual.es

    2012-08-01

    Heavy metal pollution has become a major environmental concern nowadays and the bioremediation of polluted habitats is an increasingly popular strategy due to both its efficiency and safety. A screening and selection protocol based on different composting processes was designed in order to isolate heavy metal-resistant microorganisms. A collection of 51 microorganisms was obtained and most of them showed the capability to tolerate heavy metals in multi-polluted aqueous systems (Cd(II), Cr(VI), Ni, Pb, Zn(II)), as well as to remove them. The highest detoxification ratios were observed for Pb. Some of the isolates detoxifying more than a 90% of this metal, while the other metals were removed in a range between 20% and 60%. The best isolates (Graphium putredinis, Fusarium solani, Fusarium sp. and Penicillium chrysogenum) were further assayed in order to determine the predominant removal mechanism and the potential use of their dead biomass as a biosorbent. Intracellular accumulation was the prevalent mechanism for most isolates and metals, with the exception of Ni. In this case, the proportion removed by extracellular adsorption was similar or even higher than that removed by intracellular accumulation. Thus, the efficiency of living cells was higher than that of dead biomass except in the case of Ni. - Highlights: Black-Right-Pointing-Pointer Composting is a good reservoir for the isolation of HM-resistant microorganisms. Black-Right-Pointing-Pointer Pb was the most removed heavy metal in multi-polluted aqueous systems. Black-Right-Pointing-Pointer Intracellular accumulation was the predominant mechanism for heavy metal removal. Black-Right-Pointing-Pointer Graphium putredinis, which detoxifies organic pollutants, was the most efficient isolate.

  12. The Influence of Stress Treatments on the Microbial Biomass and the Rate of Decomposition of Humified Matter in Soils Containing Different Amounts of Clay

    DEFF Research Database (Denmark)

    Sørensen, Lasse Holst

    1983-01-01

    originating from straw. The addition of unlabeled glucose accelerated the evolution of labeled CO2-C in all 4 soils. The size of the effect on CO2 evolution and on the biomass was similar to that of air-drying. Grinding killed a larger percentage of the biomass in the sandy soil than in the soils with a high...... with CHCl3 mainly consists of dormant organisms. CO2 production, the biological activity, was related to the amount of available organic material and not the size of the biomass....

  13. Feasibility study for the assessment of biomass material flows - Final report. Volume 1: main report, Volume 2: monograph of existing data sources

    International Nuclear Information System (INIS)

    Chevallier, Laurent; Forot, Virginie; Rouillon, Adrien; Rantien, Caroline; Zegers, Jean-Pierre

    2014-01-01

    This study aimed at elaborating a method of quantification of annual inter-regional, national and international biomass flows within the French market, within a perspective of integration into the French national biomass resource observatory (ONRB). This method is based on numerous existing data which are available for all French regions. Three main data sources have been selected. After a presentation of definitions and nomenclature used within these data sources, and a discussion of ways to address the flow concept, the report presents the different studied data (regional, national and international data), and then presents the adopted method for the assessments of inter-regional flows, flows between a region and the international level, and between France and the rest of the world. Recommendations are then made for the implementation and integration of this method into existing tools

  14. Using single-chamber microbial fuel cells as renewable power sources of electro-Fenton reactors for organic pollutant treatment

    International Nuclear Information System (INIS)

    Zhu, Xiuping; Logan, Bruce E.

    2013-01-01

    Highlights: ► A new type of electro-Fenton system was developed for wastewater treatment. ► Degradation efficiency of organic pollutants was substantially improved. ► Operation cost was greatly reduced compared to other microbial fuel cell designs. -- Abstract: Electro-Fenton reactions can be very effective for organic pollutant degradation, but they typically require non-sustainable electrical power to produce hydrogen peroxide. Two-chamber microbial fuel cells (MFCs) have been proposed for pollutant treatment using Fenton-based reactions, but these types of MFCs have low power densities and require expensive membranes. Here, more efficient dual reactor systems were developed using a single-chamber MFC as a low-voltage power source to simultaneously accomplish H 2 O 2 generation and Fe 2+ release for the Fenton reaction. In tests using phenol, 75 ± 2% of the total organic carbon (TOC) was removed in the electro-Fenton reactor in one cycle (22 h), and phenol was completely degraded to simple and readily biodegradable organic acids. Compared to previously developed systems based on two-chamber MFCs, the degradation efficiency of organic pollutants was substantially improved. These results demonstrate that this system is an energy-efficient and cost-effective approach for industrial wastewater treatment of certain pollutants

  15. Elevated CO2 increases Cs uptake and alters microbial communities and biomass in the rhizosphere of Phytolacca americana Linn (pokeweed) and Amaranthus cruentus L. (purple amaranth) grown on soils spiked with various levels of Cs

    International Nuclear Information System (INIS)

    Song, Ningning; Zhang, Ximei; Wang, Fangli; Zhang, Changbo; Tang, Shirong

    2012-01-01

    General concern about increasing global atmospheric CO 2 levels owing to the ongoing fossil fuel combustion and elevated levels of radionuclides in the environment, has led to growing interest in the responses of plants to interactive effects of elevated CO 2 and radionuclides in terms of phytoremediation and food safety. To assess the combined effects of elevated CO 2 and cesium contamination on plant biomass, microbial activities in the rhizosphere soil and Cs uptake, Phytolacca americana Linn (pokeweed, C3 specie) and Amaranthus cruentus L. (purple amaranth, C4 specie) were grown in pots of soils containing five levels of cesium (0, 100, 300, 500 and 1000 mg Cs kg −1 ) under two levels of CO 2 (360 and 860 μL L −1 , respectively). Shoot and root biomass of P. americana and Amaranthus crentus was generally higher under elevated CO 2 than under ambient CO 2 for all treatments. Both plant species exhibited higher Cs concentration in the shoots and roots under elevated CO 2 than ambient CO 2 . For P. americana grown at 0, 100, 300, 500 and 1000 mg Cs kg −1 , the increase magnitude of Cs concentration due to elevated CO 2 was 140, 18, 11, 34 and 15% in the shoots, and 150, 20, 14, 15 and 19% in the roots, respectively. For A. cruentus, the corresponding value was 118, 28, 21, 14 and 17% in the shoots, and 126, 6, 11, 17 and 22% in the roots, respectively. Higher bioaccumulation factors were noted for both species grown under elevated CO 2 than ambient CO 2 . The populations of bacteria, actinomycetes and fungi, and the microbial C and N in the rhizosphere soils of both species were higher at elevated CO 2 than at ambient CO 2 with the same concentration of Cs. The results suggested that elevated CO 2 significantly affected plant biomass, Cs uptake, soil C and N concentrations, and community composition of soil microbes associated with P. americana and A. cruentus roots. The knowledge gained from this investigation constitutes an important advancement in

  16. Carbono orgânico e biomassa microbiana do solo em plantios de Acacia mangium no Cerrado de Roraima Soil organic carbon and soil microbial biomass in Acacia mangium plantation in the Savanna of Roraima

    Directory of Open Access Journals (Sweden)

    Sara Magda Oliveira Simões

    2010-03-01

    Full Text Available O objetivo do estudo foi avaliar os efeitos de plantios de Acacia mangium, localizados no cerrado em Roraima, sobre o carbono orgânico e biomassa microbiana do solo. Foram realizadas amostragens de solo nas profundidades de 0-20 cm e 20-40 cm em dois plantios de A. mangium com cerca de cinco anos de idade, e em duas áreas de Cerrado nativo consideradas referência. Um dos plantios de A. mangium (localizado na Fazenda Cigolina correspondeu a um plantio homogêneo (espa��amento de 3,6 m entre linhas e 2,0 m entre plantas enquanto que o outro (localizado no Campo Experimental Água Boa - CEAB correspondeu a um plantio em faixas com duas linhas de plantio (espaçamento de 6 m entre linhas, 2,5 m entre plantas e cerca de 30 m entre faixas. As amostras de solo foram analisadas quanto ao carbono orgânico, carbono da biomassa microbiana, respiração basal do solo e quociente metabólico, além de atributos químicos de fertilidade. Foi verificado que os plantios de A. mangium não proporcionaram aumentos significativos do carbono orgânico do solo em comparação às áreas de referência. Entretanto, na média geral, esses plantios proporcionaram aumento do carbono da biomassa microbiana do solo e redução do quociente metabólico, indicando a possibilidade de acúmulo de carbono orgânico no solo em longo prazo. Também foi observado que, em comparação ao plantio da fazenda Cigolina e às áreas de referência, o carbono microbiano do solo foi maior e acompanhado de menor quociente metabólico no plantio de A. mangium no CEAB, mostrando que a estrutura de plantio exerceu influência sobre a biomassa microbiana do solo.The aim of this study was to evaluate the effects of Acacia mangium plantation in the Roraima's Savanna, on soil organic carbon and soil microbial biomass. Soil samplings were collected on the depths of 0-20 cm and 20-40 cm in two Acacia mangium plantation sites, about five years old, and in two sites of native savanna as

  17. 40 CFR 141.402 - Ground water source microbial monitoring and analytical methods.

    Science.gov (United States)

    2010-07-01

    ... approves the use of E. coli as a fecal indicator for source water monitoring under this paragraph (a). If the repeat sample collected from the ground water source is E.coli positive, the system must comply... listed in the in paragraph (c)(2) of this section for the presence of E. coli, enterococci, or coliphage...

  18. Methods and compositions for identification of source of microbial contamination in a sample

    Science.gov (United States)

    Andersen, Gary L.; Dubinsky, Eric A.

    2017-08-08

    Herein are described 1058 different bacterial taxa that were unique to either human, grazing mammal, or bird fecal wastes. These identified taxa can serve as specific identifier taxa for these sources in environmental waters. Two field tests in marine waters demonstrate the capacity of phylogenetic microarray analysis to track multiple sources with one test.

  19. Microbial biomass and activity in litter during the initial development of pure and mixed plantations of Eucalyptus grandis and Acacia mangium Biomassa e atividade microbiana da serapilheira durante o desenvolvimento inicial de plantios puros e mistos de Eucalyptus grandis e Acacia mangium

    Directory of Open Access Journals (Sweden)

    Daniel Bini

    2013-02-01

    Full Text Available Studies on microbial activity and biomass in forestry plantations often overlook the role of litter, typically focusing instead on soil nutrient contents to explain plant and microorganism development. However, since the litter is a significant source of recycled nutrients that affect nutrient dynamics in the soil, litter composition may be more strongly correlated with forest growth and development than soil nutrient contents. This study aimed to test this hypothesis by examining correlations between soil C, N, and P; litter C, N, P, lignin content, and polyphenol content; and microbial biomass and activity in pure and mixed second-rotation plantations of Eucalyptus grandis and Acacia mangium before and after senescent leaf drop. The numbers of cultivable fungi and bacteria were also estimated. All properties were correlated with litter C, N, P, lignin and polyphenols, and with soil C and N. We found higher microbial activity (CO2 evolution in litter than in soil. In the E. grandis monoculture before senescent leaf drop, microbial biomass C was 46 % higher in litter than in soil. After leaf drop, this difference decreased to 16 %. In A. mangium plantations, however, microbial biomass C was lower in litter than in soil both before and after leaf drop. Microbial biomass N of litter was approximately 94 % greater than that of the soil in summer and winter in all plantations. The number of cultivable fungi and bacteria increased after leaf drop, especially so in the litter. Fungi were also more abundant in the E. grandis litter. In general, the A. mangium monoculture was associated with higher levels of litter lignin and N, especially after leaf drop. In contrast, the polyphenol and C levels in E. grandis monoculture litter were higher after leaf drop. These properties were negatively correlated with total soil C and N. Litter in the mixed stands had lower C:N and C:P ratios and higher N, P, and C levels in the microbial biomass. This suggests more

  20. Hunger for carbon dioxide. Foundation of the 'Task Force Biomass' for the development of new energy sources; Hunger nach Kohlendioxid. 'Task Force Biomasse' zur Erschliessung neuer Energiequellen gegruendet

    Energy Technology Data Exchange (ETDEWEB)

    Schlaefer, Susanne; Bayer, Thomas [Infraserv GmbH und Co. Hoechst KG, Frankfurt am Main (Germany)

    2009-10-15

    At the industrial park Hoechst (Frankfurt / Main, Federal Republic of Germany), Infraserv GmbH and Co. Hoechst KG pursues the disposal conception ''Waste to Energy'' in order to supply electricity and steam for the approximately 90 producing companies at the location. The company now looks for possibilities in order to develop new energy sources. The keyword is ''innovative biomass''. Among other things the possibility of power generation from algae belongs to this.

  1. Growth and content of Spirulina platensis biomass chlorophyll cultivated at different values of light intensity and temperature using different nitrogen sources

    Directory of Open Access Journals (Sweden)

    Eliane Dalva Godoy Danesi

    2011-03-01

    Full Text Available The effects of light intensity and temperature in S. platensis cultivation with potassium nitrate or urea as nitrogen source were investigated, as well as the biomass chlorophyll contents of this cyanobacteria, through the Response Surface Methodology. Experiments were performed at temperatures from 25 to 34.5ºC and light intensities from 15 to 69 µmol photons m-2 s-1, in mineral medium. In cultivations with both sources of nitrogen, KNO3 and urea, statistic evaluation through multiple regression, no interactions of such independent variables were detected in the results of the dependent variables maximum cell concentration, chlorophyll biomass contents, cell and chlorophyll productivities, as well as in the nitrogen-cell conversion factor. In cultivation performed with both sources of nitrogen, it was possible to obtain satisfactory adjustments to relate the dependent variables to the independent variables. The best results were achieved at temperature of 30ºC, at light intensity of 60 µmol photons m-2s-1, for cell growth, with cell productivity of approximately 95 mg L-1 d-1 in cultivations with urea. For the chlorophyll biomass content, the most adequate light intensity was 24 µmol photons m-2 s-1.

  2. Source apportionment of PM2.5 at a regional background site in North China using PMF linked with radiocarbon analysis: insight into the contribution of biomass burning

    Directory of Open Access Journals (Sweden)

    Z. Zong

    2016-09-01

    Full Text Available Source apportionment of fine particles (PM2.5 at a background site in North China in the winter of 2014 was done using statistical analysis, radiocarbon (14C measurement and positive matrix factorization (PMF modeling. Results showed that the concentration of PM2.5 was 77.6 ± 59.3 µg m−3, of which sulfate (SO42− concentration was the highest, followed by nitrate (NO3−, organic carbon (OC, elemental carbon (EC and ammonium (NH4+. As demonstrated by backward trajectory, more than half of the air masses during the sampling period were from the Beijing–Tianjin–Hebei (BTH region, followed by Mongolia and the Shandong Peninsula. Cluster analysis of chemical species suggested an obvious signal of biomass burning in the PM2.5 from the Shandong Peninsula, while the PM2.5 from the BTH region showed a vehicle emission pattern. This finding was further confirmed by the 14C measurement of OC and EC in two merged samples. The 14C result indicated that biogenic and biomass burning emission contributed 59 ± 4 and 52 ± 2 % to OC and EC concentrations, respectively, when air masses originated from the Shandong Peninsula, while the contributions fell to 46 ± 4 and 38 ± 1 %, respectively, when the prevailing wind changed and came from the BTH region. The minimum deviation between source apportionment results from PMF and 14C measurement was adopted as the optimal choice of the model exercises. Here, two minor overestimates with the same range (3 % implied that the PMF result provided a reasonable source apportionment of the regional PM2.5 in this study. Based on the PMF modeling, eight sources were identified; of these, coal combustion, biomass burning and vehicle emission were the main contributors of PM2.5, accounting for 29.6, 19.3 and 15.9 %, respectively. Compared with overall source apportionment, the contributions of vehicle emission, mineral dust, coal combustion and biomass burning increased when air masses

  3. Comparison of Microbial and Chemical Source Tracking Markers To Identify Fecal Contamination Sources in the Humber River (Toronto, Ontario, Canada) and Associated Storm Water Outfalls.

    Science.gov (United States)

    Staley, Zachery R; Grabuski, Josey; Sverko, Ed; Edge, Thomas A

    2016-11-01

    Storm water runoff is a major source of pollution, and understanding the components of storm water discharge is essential to remediation efforts and proper assessment of risks to human and ecosystem health. In this study, culturable Escherichia coli and ampicillin-resistant E. coli levels were quantified and microbial source tracking (MST) markers (including markers for general Bacteroidales spp., human, ruminant/cow, gull, and dog) were detected in storm water outfalls and sites along the Humber River in Toronto, Ontario, Canada, and enumerated via endpoint PCR and quantitative PCR (qPCR). Additionally, chemical source tracking (CST) markers specific for human wastewater (caffeine, carbamazepine, codeine, cotinine, acetaminophen, and acesulfame) were quantified. Human and gull fecal sources were detected at all sites, although concentrations of the human fecal marker were higher, particularly in outfalls (mean outfall concentrations of 4.22 log 10 copies, expressed as copy numbers [CN]/100 milliliters for human and 0.46 log 10 CN/100 milliliters for gull). Higher concentrations of caffeine, acetaminophen, acesulfame, E. coli, and the human fecal marker were indicative of greater raw sewage contamination at several sites (maximum concentrations of 34,800 ng/liter, 5,120 ng/liter, 9,720 ng/liter, 5.26 log 10 CFU/100 ml, and 7.65 log 10 CN/100 ml, respectively). These results indicate pervasive sewage contamination at storm water outfalls and throughout the Humber River, with multiple lines of evidence identifying Black Creek and two storm water outfalls with prominent sewage cross-connection problems requiring remediation. Limited data are available on specific sources of pollution in storm water, though our results indicate the value of using both MST and CST methodologies to more reliably assess sewage contamination in impacted watersheds. Storm water runoff is one of the most prominent non-point sources of biological and chemical contaminants which can

  4. Basaltic substrate composition affects microbial community development and acts as a source of nutrients in the deep biosphere

    Science.gov (United States)

    Bailey, B.; Sudek, L.; Templeton, A.; Staudigel, H.; Tebo, B.; Moyer, C.; Davis, R.

    2006-12-01

    Studies of the oceanic crust over the past decade have revealed that in spite of the oligotrophic nature of this environment, a diverse biosphere is present in the upper 1 km of basaltic crust. The key energy source in this setting may be the high content of transistion metals (Fe, Mn) found in the basaltic glass, but in order to discover the role of Fe and Mn in the deep biosphere, we must first determine which microbes are present and how they attain the necessary metabolites for proliferation. Our work contributes to both questions through the use of molecular microbiology techniques and the exposure of specifically designed substrates on the ocean floor. Loihi Seamount off the southeast coast of the Big Island of Hawai'i provides a unique laboratory for the study of distribution and population of microbial communities associated with iron rich environments on the ocean floor. Iron oxide flocculent material (floc) dominates the direct and diffuse hydrothermal venting areas on Loihi which makes it a prime target for understanding the role of iron in biological systems in the deep biosphere. We collected iron oxide floc and basaltic glass from pillow basalts around several hydrothermal vents on the crater rim, within the pit crater Pele's Pit, and from deep off of the southern rift zone of Loihi using the HURL PISCES IV/V submersibles. We also deployed basaltic glass sand amended with various nutrients (phosphate, oxidized and reduced iron, manganese) and recovered them in subsequent years to determine how substrate composition affects community structure. We extracted DNA from both rock and iron flocs and used t-RFLP to obtain a genetic fingerprint of the microbial communities associated with each substrate. From olivine and tholeiitic basalt enrichments, it appears that substrate composition strongly influences microbial colonization and subsequent community development even when deployed in the same conditions. Culturing efforts have yielded several iron

  5. Characterization of two diesel fuel degrading microbial consortia enriched from a non acclimated, complex source of microorganisms

    Directory of Open Access Journals (Sweden)

    Varese Giovanna C

    2010-02-01

    Full Text Available Abstract Background The bioremediation of soils impacted by diesel fuels is very often limited by the lack of indigenous microflora with the required broad substrate specificity. In such cases, the soil inoculation with cultures with the desired catabolic capabilities (bioaugmentation is an essential option. The use of consortia of microorganisms obtained from rich sources of microbes (e.g., sludges, composts, manure via enrichment (i.e., serial growth transfers on the polluting hydrocarbons would provide bioremediation enhancements more robust and reproducible than those achieved with specialized pure cultures or tailored combinations (co-cultures of them, together with none or minor risks of soil loading with unrelated or pathogenic allocthonous microorganisms. Results In this work, two microbial consortia, i.e., ENZ-G1 and ENZ-G2, were enriched from ENZYVEBA (a complex commercial source of microorganisms on Diesel (G1 and HiQ Diesel (G2, respectively, and characterized in terms of microbial composition and hydrocarbon biodegradation capability and specificity. ENZ-G1 and ENZ-G2 exhibited a comparable and remarkable biodegradation capability and specificity towards n-C10 to n-C24 linear paraffins by removing about 90% of 1 g l-1 of diesel fuel applied after 10 days of aerobic shaken flask batch culture incubation at 30°C. Cultivation dependent and independent approaches evidenced that both consortia consist of bacteria belonging to the genera Chryseobacterium, Acinetobacter, Psudomonas, Stenotrophomonas, Alcaligenes and Gordonia along with the fungus Trametes gibbosa. However, only the fungus was found to grow and remarkably biodegrade G1 and G2 hydrocarbons under the same conditions. The biodegradation activity and specificity and the microbial composition of ENZ-G1 and ENZ-G2 did not significantly change after cryopreservation and storage at -20°C for several months. Conclusions ENZ-G1 and ENZ-G2 are very similar highly enriched consortia

  6. Characterization of two diesel fuel degrading microbial consortia enriched from a non acclimated, complex source of microorganisms.

    Science.gov (United States)

    Zanaroli, Giulio; Di Toro, Sara; Todaro, Daniela; Varese, Giovanna C; Bertolotto, Antonio; Fava, Fabio

    2010-02-16

    The bioremediation of soils impacted by diesel fuels is very often limited by the lack of indigenous microflora with the required broad substrate specificity. In such cases, the soil inoculation with cultures with the desired catabolic capabilities (bioaugmentation) is an essential option. The use of consortia of microorganisms obtained from rich sources of microbes (e.g., sludges, composts, manure) via enrichment (i.e., serial growth transfers) on the polluting hydrocarbons would provide bioremediation enhancements more robust and reproducible than those achieved with specialized pure cultures or tailored combinations (co-cultures) of them, together with none or minor risks of soil loading with unrelated or pathogenic allocthonous microorganisms. In this work, two microbial consortia, i.e., ENZ-G1 and ENZ-G2, were enriched from ENZYVEBA (a complex commercial source of microorganisms) on Diesel (G1) and HiQ Diesel (G2), respectively, and characterized in terms of microbial composition and hydrocarbon biodegradation capability and specificity. ENZ-G1 and ENZ-G2 exhibited a comparable and remarkable biodegradation capability and specificity towards n-C10 to n-C24 linear paraffins by removing about 90% of 1 g l-1 of diesel fuel applied after 10 days of aerobic shaken flask batch culture incubation at 30 degrees C. Cultivation dependent and independent approaches evidenced that both consortia consist of bacteria belonging to the genera Chryseobacterium, Acinetobacter, Psudomonas, Stenotrophomonas, Alcaligenes and Gordonia along with the fungus Trametes gibbosa. However, only the fungus was found to grow and remarkably biodegrade G1 and G2 hydrocarbons under the same conditions. The biodegradation activity and specificity and the microbial composition of ENZ-G1 and ENZ-G2 did not significantly change after cryopreservation and storage at -20 degrees C for several months. ENZ-G1 and ENZ-G2 are very similar highly enriched consortia of bacteria and a fungus capable of

  7. Water Sources and Their Protection from the Impact of Microbial Contamination in Rural Areas of Beijing, China

    Directory of Open Access Journals (Sweden)

    Hairong Li

    2013-03-01

    Full Text Available Bacterial contamination of drinking water is a major public health problem in rural China. To explore bacterial contamination in rural areas of Beijing and identify possible causes of bacteria in drinking water samples, water samples were collected from wells in ten rural districts of Beijing, China. Total bacterial count, total coliforms and Escherichia coli in drinking water were then determined and water source and wellhead protection were investigated. The bacterial contamination in drinking water was serious in areas north of Beijing, with the total bacterial count, total coliforms and Escherichia coli in some water samples reaching 88,000 CFU/mL, 1,600 MPN/100 mL and 1,600 MPN/100 mL, respectively. Water source types, well depth, whether the well was adequately sealed and housed, and whether wellhead is above or below ground were the main factors influencing bacterial contamination levels in drinking water. The bacterial contamination was serious in the water of shallow wells and wells that were not closed, had no well housing or had a wellhead below ground level. The contamination sources around wells, including village dry toilets and livestock farms, were well correlated with bacterial contamination. Total bacterial counts were affected by proximity to sewage ditches and polluting industries, however, proximity to landfills did not influence the microbial indicators.

  8. Advanced system demonstration for utilization of biomass as an energy source. Volume I. Scope and design criteria and project summary

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-10-01

    The information in this document is the result of an intensive engineering effort to demonstrate the feasibility of biomass-fueled boilers in cogeneration applications. This design package is based upon a specific site in the State of Maine. However, the design is generic in nature and could serve as a model for other biomass conversion facilities located anywhere biomass is abundant. The project's purpose and summary information are presented: the plant, its concept of operation; and other overall information are described. The capital cost estimate for the plant, and the basis upon which it was obtained are given; a schedule of key milestones and activities required to construct the plant and put it into operation is presented; and the general findings in areas that affect the viability of the project are discussed. The technical design, biomass study, environmental impact, commercialization, and economic factors are addressed. Each major plant area and the equipment and facilities that each includes are discussed in depth. Some overall plant requirements, including noise control, reliability, maintainability, and safety, are detailed. The results of each study relating to alternatives considered for optimizing plant operation parameters and specific system process schemes are briefly presented. All economic factors that affect the feasibility and viability of the biomass project are defined and evaluated.

  9. Nitrogen recycling from fuel-extracted algal biomass: residuals as the sole nitrogen source for culturing Scenedesmus acutus.

    Science.gov (United States)

    Gu, Huiya; Nagle, Nick; Pienkos, Philip T; Posewitz, Matthew C

    2015-05-01

    In this study, the reuse of nitrogen from fuel-extracted algal residues was investigated. The alga Scenedesmus acutus was found to be able to assimilate nitrogen contained in amino acids, yeast extracts, and proteinaceous alga residuals. Moreover, these alternative nitrogen resources could replace nitrate in culturing media. The ability of S. acutus to utilize the nitrogen remaining in processed algal biomass was unique among the promising biofuel strains tested. This alga was leveraged in a recycling approach where nitrogen is recovered from algal biomass residuals that remain after lipids are extracted and carbohydrates are fermented to ethanol. The protein-rich residuals not only provided an effective nitrogen resource, but also contributed to a carbon "heterotrophic boost" in subsequent culturing, improving overall biomass and lipid yields relative to the control medium with only nitrate. Prior treatment of the algal residues with Diaion HP20 resin was required to remove compounds inhibitory to algal growth. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Microbial quality of improved drinking water sources: evidence from western Kenya and southern Vietnam.

    Science.gov (United States)

    Grady, Caitlin A; Kipkorir, Emmanuel C; Nguyen, Kien; Blatchley, E R

    2015-06-01

    In recent decades, more than 2 billion people have gained access to improved drinking water sources thanks to extensive effort from governments, and public and private sector entities. Despite this progress, many water sector development interventions do not provide access to safe water or fail to be sustained for long-term use. The authors examined drinking water quality of previously implemented water improvement projects in three communities in western Kenya and three communities in southern Vietnam. The cross-sectional study of 219 households included measurements of viable Escherichia coli. High rates of E. coli prevalence in these improved water sources were found in many of the samples. These findings suggest that measures above and beyond the traditional 'improved source' definition may be necessary to ensure truly safe water throughout these regions.

  11. Global inventory of NOx sources

    International Nuclear Information System (INIS)

    Delmas, R.; Serca, D.; Jambert, C.

    1997-01-01

    Nitrogen oxides are key compounds for the oxidation capacity of the troposphere. Their concentration depends on the proximity of sources because of their short atmospheric lifetime. An accurate knowledge of the distribution of their sources and sinks is therefore crucial. At the global scale, the dominant sources of nitrogen oxides - combustion of fossil fuel (about 50%) and biomass burning (about 20%) - are basically anthropogenic. Natural sources, including lightning and microbial activity in soils, represent therefore less than 30% of total emissions. Fertilizer use in agriculture constitutes an anthropogenic perturbation to the microbial source. The methods to estimate the magnitude and distribution of these dominant sources of nitrogen oxides are discussed. Some minor sources which may play a specific role in tropospheric chemistry such as NO x emission from aircraft in the upper troposphere or input from production in the stratosphere from N 2 O photodissociation are also considered

  12. Source indicators of biomass burning associated with inorganic salts and carboxylates in dry season ambient aerosol in Chiang Mai Basin, Thailand

    Science.gov (United States)

    Tsai, Ying I.; Sopajaree, Khajornsak; Chotruksa, Auranee; Wu, Hsin-Ching; Kuo, Su-Ching

    2013-10-01

    PM10 aerosol was collected between February and April 2010 at an urban site (CMU) and an industrial site (TOT) in Chiang Mai, Thailand, and characteristics and provenance of water-soluble inorganic species, carboxylates, anhydrosugars and sugar alcohols were investigated with particular reference to air quality, framed as episodic or non-episodic pollution. Sulfate, a product of secondary photochemical reactions, was the major inorganic salt in PM10, comprising 25.9% and 22.3% of inorganic species at CMU and TOT, respectively. Acetate was the most abundant monocarboxylate, followed by formate. Oxalate was the dominant dicarboxylate. A high acetate/formate mass ratio indicated that primary traffic-related and biomass-burning emissions contributed to Chiang Mai aerosols during episodic and non-episodic pollution. During episodic pollution carboxylate peaks indicated sourcing from photochemical reactions and/or directly from traffic-related and biomass burning processes and concentrations of specific biomarkers of biomass burning including water-soluble potassium, glutarate, oxalate and levoglucosan dramatically increased. Levoglucosan, the dominant anhydrosugar, was highly associated with water-soluble potassium (r = 0.75-0.79) and accounted for 93.4% and 93.7% of anhydrosugars at CMU and TOT, respectively, during episodic pollution. Moreover, levoglucosan during episodic pollution was 14.2-21.8 times non-episodic lows, showing clearly that emissions from biomass burning are the major cause of PM10 episodic pollution in Chiang Mai. Additionally, the average levoglucosan/mannosan mass ratio during episodic pollution was 14.1-14.9, higher than the 5.73-7.69 during non-episodic pollution, indicating that there was more hardwood burning during episodic pollution. Higher concentrations of glycerol and erythritol during episodic pollution further indicate that biomass burning activities released soil biota from forest and farmland soils.

  13. Microbial pathogens in source and treated waters from drinking water treatment plants in the US

    Science.gov (United States)

    An occurrence survey was conducted on selected pathogens in source and treated drinking water collected from 25 drinking water treatment plants (DWTPs) in the United States. Water samples were analyzed for the protozoa Giardia and Cryptosporidium (EPA Method 1623); the fungi Asp...

  14. Biomass Energy | Climate Neutral Research Campuses | NREL

    Science.gov (United States)

    Biomass Energy Biomass Energy Biomass from local sources can be key to a campus climate action plan biomass may fit into your campus climate action plan. Campus Options Considerations Sample Project Related biomass fuels for energy does not add to the net amount of carbon in the atmosphere. This is because the

  15. Biomassa e atividade microbianas do solo sob influência de chumbo e da rizosfera da soja micorrizada Soil microbial biomass and activity under the influence of lead addition and mycorrhizal soybean rhizosphere

    Directory of Open Access Journals (Sweden)

    Sara Adrián López de Andrade

    2004-12-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito da adição de chumbo (Pb ao solo na biomassa e atividade microbianas do solo sob influência da rizosfera de soja micorrizada. O trabalho foi realizado em casa de vegetação, com delineamento inteiramente casualizado num esquema fatorial 4x2x2 utilizando-se 0, 150, 300 e 600 mg dm-3 de Pb, inoculação ou não do fungo micorrízico arbuscular (FMA, Glomus macrocarpum, e duas épocas de amostragem - florescimento e maturação da soja. Avaliaram-se o C da biomassa microbiana, a liberação de CO2 do solo e a atividade de três enzimas, desidrogenase, fosfatase alcalina e arilssulfatase. O Pb afetou negativamente o C da biomassa e a atividade da microbiota rizosférica, ocorrendo interação entre a presença de propágulos de FMA e o estádio de desenvolvimento da planta. A atividade da fosfatase alcalina foi a mais afetada pelas altas concentrações de Pb adicionadas ao solo, com redução de 60% na sua atividade, mostrando-se um indicador sensível do estresse metabólico da comunidade microbiana do solo causado pelo excesso de chumbo. A micorrização da soja influenciou de forma direta a microbiota rizosférica, resultando em maior atividade e biomassa, principalmente no estádio de maturação da soja. A microbiota do solo apresentou sintomas de estresse decorrentes da adição de chumbo.The objective of this work was to evaluate the effects of lead addition on soil microbial biomass and activity under the influence of the rhizosphere of mycorrhizal soybean. The experimental design was completely randomized and arranged in a 4x2x2 factorial scheme, using 0, 150, 300 and 600 mg dm-3, inoculation or not of the arbuscular mycorrhizal fungus (AMF Glomus macrocarpum and two sampling periods: soybean flowering and maturity. Microbial biomass C, soil respiration and the activity of three soil enzymes (deshydrogenase, alkaline phosphatase and arilsulphatase were determined. The most affected enzyme

  16. Electrifying biomass

    International Nuclear Information System (INIS)

    Kusnierczyk, D.

    2005-01-01

    British Columbia's (BC) energy plan was outlined in this PowerPoint presentation. BC Hydro is the third largest electric utility in Canada with a generating capacity of 11,000 MW, 90 per cent of which is hydro generation. Various independent power project (IPP) biomass technologies were outlined, including details of biogas, wood residue and municipal solid waste facilities. An outline of BC Hydro's overall supply mix was presented, along with details of the IPP supply mix. It was suggested that the cancellation of the Duke Point power project has driven growth in the renewable energy sector. A chart of potential energy contribution by resource type was presented, as well as unit energy cost ranges. Resources included small and large hydro; demand side management; resource smart natural gas; natural gas; coal; wind; geothermal; biomass; wave; and tidal. The acquisition process was reviewed. Details of calls for tenders were presented, and issues concerning bidder responsibility and self-selection were examined. It was observed that wood residue presents a firm source of electricity that is generally local, and has support from the public. In addition, permits for wood residue energy conversion are readily available. However, size limitations, fuel risks, and issues concerning site control may prove to be significant challenges. It was concluded that the success of biomass energy development will depend on adequate access and competitive pricing. tabs., figs

  17. Utilization of fruit peels as carbon source for white rot fungi biomass production under submerged state bioconversion

    Directory of Open Access Journals (Sweden)

    Olorunnisola Kola Saheed

    2016-04-01

    Full Text Available The present generation of nutrient rich waste streams within the food and hospitality industry is inevitable and remained a matter of concern to stakeholders. Three white rot fungal strains were cultivated under submerged state bioconversion (SmB. Fermentable sugar conversion efficiency, biomass production and substrate utilization constant were indicators used to measure the success of the process. The substrates – banana peel (Bp, pineapple peel (PAp and papaya peel (Pp were prepared in wet and dried forms as substrates. Phanerochaete chrysosporium (P. chrysosporium, Panus tigrinus M609RQY, and RO209RQY were cultivated on sole fruit wastes and their composites. All fungal strains produced profound biomass on dry sole wet substrates, but wet composite substrates gave improved results. P. tigrinus RO209RQY was the most efficient in sugar conversion (99.6% on sole substrates while P. tigrinus M609RQY was efficient on composite substrates. Elevated substrate utilization constant (Ku and biomass production heralded wet composite substrates. P. chrysosporium was the most performing fungal strain for biomass production, while PApBp was the best composite substrate.

  18. Remarks on energetic biomass

    International Nuclear Information System (INIS)

    Mathis, Paul; Pelletier, Georges

    2011-01-01

    The authors report a study of energy biomass by considering its three main sources (forest, agriculture and wastes) and three energy needs (heat, fuel for transports, electricity) in the French national context. After having recalled the various uses of biomass (animal feeding, energy production, materials, chemical products), the aut