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Sample records for microbial production system

  1. Systems biology of microbial exopolysaccharides production

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    Ozlem eAtes

    2015-12-01

    Full Text Available Exopolysaccharides (EPS produced by diverse group of microbial systems are rapidly emerging as new and industrially important biomaterials. Due to their unique and complex chemical structures and many interesting physicochemical and rheological properties with novel functionality, the microbial EPSs find wide range of commercial applications in various fields of the economy such as food, feed, packaging, chemical, textile, cosmetics and pharmaceutical industry, agriculture and medicine. EPSs are mainly associated with high-value applications and they have received considerable research attention over recent decades with their biocompatibility, biodegradability, and both environmental and human compatibility. However only a few microbial EPSs have achieved to be used commercially due to their high production costs. The emerging need to overcome economic hurdles and the increasing significance of microbial EPSs in industrial and medical biotechnology call for the elucidation of the interrelations between metabolic pathways and EPS biosynthesis mechanism in order to control and hence enhance its microbial productivity. Moreover a better understanding of biosynthesis mechanism is a significant issue for improvement of product quality and properties and also for the design of novel strains. Therefore a systems-based approach constitutes an important step towards understanding the interplay between metabolism and EPS biosynthesis and further enhances its metabolic performance for industrial application. In this review, primarily the microbial EPSs, their biosynthesis mechanism and important factors for their production will be discussed. After this brief introduction, recent literature on the application of omics technologies and systems biology tools for the improvement of production yields will be critically evaluated. Special focus will be given to EPSs with high market value such as xanthan, levan, pullulan and dextran.

  2. Systems Biology of Microbial Exopolysaccharides Production.

    Science.gov (United States)

    Ates, Ozlem

    2015-01-01

    Exopolysaccharides (EPSs) produced by diverse group of microbial systems are rapidly emerging as new and industrially important biomaterials. Due to their unique and complex chemical structures and many interesting physicochemical and rheological properties with novel functionality, the microbial EPSs find wide range of commercial applications in various fields of the economy such as food, feed, packaging, chemical, textile, cosmetics and pharmaceutical industry, agriculture, and medicine. EPSs are mainly associated with high-value applications, and they have received considerable research attention over recent decades with their biocompatibility, biodegradability, and both environmental and human compatibility. However, only a few microbial EPSs have achieved to be used commercially due to their high production costs. The emerging need to overcome economic hurdles and the increasing significance of microbial EPSs in industrial and medical biotechnology call for the elucidation of the interrelations between metabolic pathways and EPS biosynthesis mechanism in order to control and hence enhance its microbial productivity. Moreover, a better understanding of biosynthesis mechanism is a significant issue for improvement of product quality and properties and also for the design of novel strains. Therefore, a systems-based approach constitutes an important step toward understanding the interplay between metabolism and EPS biosynthesis and further enhances its metabolic performance for industrial application. In this review, primarily the microbial EPSs, their biosynthesis mechanism, and important factors for their production will be discussed. After this brief introduction, recent literature on the application of omics technologies and systems biology tools for the improvement of production yields will be critically evaluated. Special focus will be given to EPSs with high market value such as xanthan, levan, pullulan, and dextran.

  3. Synthetic and systems biology for microbial production of commodity chemicals.

    Science.gov (United States)

    Chubukov, Victor; Mukhopadhyay, Aindrila; Petzold, Christopher J; Keasling, Jay D; Martín, Héctor García

    2016-01-01

    The combination of synthetic and systems biology is a powerful framework to study fundamental questions in biology and produce chemicals of immediate practical application such as biofuels, polymers, or therapeutics. However, we cannot yet engineer biological systems as easily and precisely as we engineer physical systems. In this review, we describe the path from the choice of target molecule to scaling production up to commercial volumes. We present and explain some of the current challenges and gaps in our knowledge that must be overcome in order to bring our bioengineering capabilities to the level of other engineering disciplines. Challenges start at molecule selection, where a difficult balance between economic potential and biological feasibility must be struck. Pathway design and construction have recently been revolutionized by next-generation sequencing and exponentially improving DNA synthesis capabilities. Although pathway optimization can be significantly aided by enzyme expression characterization through proteomics, choosing optimal relative protein expression levels for maximum production is still the subject of heuristic, non-systematic approaches. Toxic metabolic intermediates and proteins can significantly affect production, and dynamic pathway regulation emerges as a powerful but yet immature tool to prevent it. Host engineering arises as a much needed complement to pathway engineering for high bioproduct yields; and systems biology approaches such as stoichiometric modeling or growth coupling strategies are required. A final, and often underestimated, challenge is the successful scale up of processes to commercial volumes. Sustained efforts in improving reproducibility and predictability are needed for further development of bioengineering.

  4. Biohydrogen production in the suspended and attached microbial growth systems from waste pastry hydrolysate.

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    Han, Wei; Hu, Yunyi; Li, Shiyi; Li, Feifei; Tang, Junhong

    2016-10-01

    Waste pastry was hydrolyzed by glucoamylase and protease which were obtained from solid state fermentation of Aspergillus awamori and Aspergillus oryzae to produce waste pastry hydrolysate. Then, the effects of hydraulic retention times (HRTs) (4-12h) on hydrogen production rate (HPR) in the suspended microbial growth system (continuous stirred tank reactor, CSTR) and attached microbial growth system (continuous mixed immobilized sludge reactor, CMISR) from waste pastry hydrolysate were investigated. The maximum HPRs of CSTR (201.8mL/(h·L)) and CMISR (255.3mL/(h·L)) were obtained at HRT of 6h and 4h, respectively. The first-order reaction could be used to describe the enzymatic hydrolysis of waste pastry. The carbon content of the waste pastry remained 22.8% in the undigested waste pastry and consumed 77.2% for carbon dioxide and soluble microbial products. To our knowledge, this is the first study which reports biohydrogen production from waste pastry. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Integrated systems for biopolymers and bioenergy production from organic waste and by-products: a review of microbial processes.

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    Pagliano, Giorgia; Ventorino, Valeria; Panico, Antonio; Pepe, Olimpia

    2017-01-01

    Recently, issues concerning the sustainable and harmless disposal of organic solid waste have generated interest in microbial biotechnologies aimed at converting waste materials into bioenergy and biomaterials, thus contributing to a reduction in economic dependence on fossil fuels. To valorize biomass, waste materials derived from agriculture, food processing factories, and municipal organic waste can be used to produce biopolymers, such as biohydrogen and biogas, through different microbial processes. In fact, different bacterial strains can synthesize biopolymers to convert waste materials into valuable intracellular (e.g., polyhydroxyalkanoates) and extracellular (e.g., exopolysaccharides) bioproducts, which are useful for biochemical production. In particular, large numbers of bacteria, including Alcaligenes eutrophus , Alcaligenes latus , Azotobacter vinelandii , Azotobacter chroococcum , Azotobacter beijerincki , methylotrophs, Pseudomonas spp., Bacillus spp., Rhizobium spp., Nocardia spp., and recombinant Escherichia coli , have been successfully used to produce polyhydroxyalkanoates on an industrial scale from different types of organic by-products. Therefore, the development of high-performance microbial strains and the use of by-products and waste as substrates could reasonably make the production costs of biodegradable polymers comparable to those required by petrochemical-derived plastics and promote their use. Many studies have reported use of the same organic substrates as alternative energy sources to produce biogas and biohydrogen through anaerobic digestion as well as dark and photofermentation processes under anaerobic conditions. Therefore, concurrently obtaining bioenergy and biopolymers at a reasonable cost through an integrated system is becoming feasible using by-products and waste as organic carbon sources. An overview of the suitable substrates and microbial strains used in low-cost polyhydroxyalkanoates for biohydrogen and biogas

  6. Microbial quality and bioactive constituents of sweet peppers from sustainable production systems.

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    Marín, Alicia; Gil, María I; Flores, Pilar; Hellín, Pilar; Selma, María V

    2008-12-10

    Integrated, organic, and soil-less production systems are the principal production practices that have emerged to encourage more sustainable agricultural practices and safer edible plants, reducing inputs of plaguicides, pesticides, and fertilizers. Sweet peppers grown commercially under integrated, organic, and soil-less production systems were compared to study the influence of these sustainable production systems on the microbial quality and bioactive constituents (vitamin C, individual and total carotenoids, hydroxycinnamic acids, and flavonoids). The antioxidant composition of peppers was analyzed at green and red maturity stages and at three harvest times (initial, middle, and late season). Irrigation water, manure, and soil were shown to be potential transmission sources of pathogens to the produce. Coliform counts of soil-less peppers were up to 2.9 log units lower than those of organic and integrated peppers. Soil-less green and red peppers showed maximum vitamin C contents of 52 and 80 mg 100 g(-1) fresh weight (fw), respectively, similar to those grown in the organic production system. Moreover, the highest content of total carotenoids was found in the soil-less red peppers, which reached a maximum of 148 mg 100 g(-1) fw, while slightly lower contents were found in integrated and organic red peppers. Hydroxycinnamic acids and flavonoids represented 15 and 85% of the total phenolic content, respectively. Total phenolic content, which ranged from 1.2 to 4.1 mg 100 g(-1) fw, was significantly affected by the harvest time but not by the production system assayed. Soil-less peppers showed similar or even higher concentrations of bioactive compounds (vitamin C, provitamin A, total carotenoid, hydroxycinnamic acids, and flavonoids) than peppers grown under organic and integrated practices. Therefore, in the commercial conditions studied, soil-less culture was a more suitable alternative than organic or integrated practices, because it improved the microbial

  7. Microbial products II

    Energy Technology Data Exchange (ETDEWEB)

    Pape, H; Rehm, H J [eds.

    1986-01-01

    The present volume deals mainly with compounds which have been detected as natural microbial products. Part 1 of this volume introduces the general aspects of the overproduction of metabolites and the concepts and genetics of secondary metabolism. Compounds such as nucleosides, nucleotides, coenzymes, vitamins and lipids are dealt with in part 2. Part 3 then is devoted to products and antibiotics with uses im medicine, veterinary medicine, plant protection and metabolites with antitumor activity. Several secondary metabolites have found uses in human and animal health care. With 244 figs., 109 tabs.

  8. The Influence of Ecological and Conventional Plant Production Systems on Soil Microbial Quality under Hops (Humulus lupulus)

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    Oszust, Karolina; Frąc, Magdalena; Gryta, Agata; Bilińska, Nina

    2014-01-01

    The knowledge about microorganisms—activity and diversity under hop production is still limited. We assumed that, different systems of hop production (within the same soil and climatic conditions) significantly influence on the composition of soil microbial populations and its functional activity (metabolic potential). Therefore, we compared a set of soil microbial properties in the field experiment of two hop production systems (a) ecological based on the use of probiotic preparations and organic fertilization (b) conventional—with the use of chemical pesticides and mineral fertilizers. Soil analyses included following microbial properties: The total number microorganisms, a bunch of soil enzyme activities, the catabolic potential was also assessed following Biolog EcoPlates®. Moreover, the abundance of ammonia-oxidizing archaea (AOA) was characterized by terminal restriction fragment length polymorphism analysis (T-RFLP) of PCR ammonia monooxygenase α-subunit (amoA) gene products. Conventional and ecological systems of hop production were able to affect soil microbial state in different seasonal manner. Favorable effect on soil microbial activity met under ecological, was more probably due to livestock-based manure and fermented plant extracts application. No negative influence on conventional hopyard soil was revealed. Both type of production fulfilled fertilizing demands. Under ecological production it was due to livestock-based manure fertilizers and fermented plant extracts application. PMID:24897025

  9. The Influence of Ecological and Conventional Plant Production Systems on Soil Microbial Quality under Hops (Humulus lupulus

    Directory of Open Access Journals (Sweden)

    Karolina Oszust

    2014-06-01

    Full Text Available The knowledge about microorganisms—activity and diversity under hop production is still limited. We assumed that, different systems of hop production (within the same soil and climatic conditions significantly influence on the composition of soil microbial populations and its functional activity (metabolic potential. Therefore, we compared a set of soil microbial properties in the field experiment of two hop production systems (a ecological based on the use of probiotic preparations and organic fertilization (b conventional—with the use of chemical pesticides and mineral fertilizers. Soil analyses included following microbial properties: The total number microorganisms, a bunch of soil enzyme activities, the catabolic potential was also assessed following Biolog EcoPlates®. Moreover, the abundance of ammonia-oxidizing archaea (AOA was characterized by terminal restriction fragment length polymorphism analysis (T-RFLP of PCR ammonia monooxygenase α-subunit (amoA gene products. Conventional and ecological systems of hop production were able to affect soil microbial state in different seasonal manner. Favorable effect on soil microbial activity met under ecological, was more probably due to livestock-based manure and fermented plant extracts application. No negative influence on conventional hopyard soil was revealed. Both type of production fulfilled fertilizing demands. Under ecological production it was due to livestock-based manure fertilizers and fermented plant extracts application.

  10. Managing soil microbial communities in grain production systems through cropping practices

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    Gupta, Vadakattu

    2013-04-01

    Cropping practices can significantly influence the composition and activity of soil microbial communities with consequences to plant growth and production. Plant type can affect functional capacity of different groups of biota in the soil surrounding their roots, rhizosphere, influencing plant nutrition, beneficial symbioses, pests and diseases and overall plant health and crop production. The interaction between different players in the rhizosphere is due to the plethora of carbon and nutritional compounds, root-specific chemical signals and growth regulators that originate from the plant and are modulated by the physico-chemical properties of soils. A number of plant and environmental factors and management practices can influence the quantity and quality of rhizodeposition and in turn affect the composition of rhizosphere biota communities, microbe-fauna interactions and biological processes. Some of the examples of rhizosphere interactions that are currently considered important are: proliferation of plant and variety specific genera or groups of microbiota, induction of genes involved in symbiosis and virulence, promoter activity in biocontrol agents and genes correlated with root adhesion and border cell quality and quantity. The observation of variety-based differences in rhizodeposition and associated changes in rhizosphere microbial diversity and function suggests the possibility for the development of varieties with specific root-microbe interactions targeted for soil type and environment i.e. designer rhizospheres. Spatial location of microorganisms in the heterogeneous field soil matrix can have significant impacts on biological processes. Therefore, for rhizosphere research to be effective in variable seasonal climate and soil conditions, it must be evaluated in the field and within a farming systems context. With the current focus on security of food to feed the growing global populations through sustainable agricultural production systems there is a

  11. Environmental proteomics of microbial plankton in a highly productive coastal upwelling system

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    Sowell, Sarah [Oregon State University, Corvallis; Abraham, Paul E [ORNL; Shah, Manesh B [ORNL; Verberkmoes, Nathan C [ORNL; Smith, Daniel [Oregon State University, Corvallis; Barofsky, Douglas [Oregon State University, Corvallis; Giovannoni, Stephen [Oregon State University, Corvallis

    2011-01-01

    Metaproteomics is one of a suite of new approaches providing insights into the activities of microorganisms in natural environments. Proteins, the final products of gene expression, indicate cellular priorities, taking into account both transcriptional and posttranscriptional control mechanisms that control adaptive responses. Here, we report the proteomic composition of the o 1.2 lm fraction of a microbial community from Oregon coast summer surface waters, detected with two-dimensional liquid chromatography coupled with electrospray tandem mass spectrometry. Spectra corresponding to proteins involved in protein folding and biosynthesis, transport, and viral capsid structure were the most frequently detected. A total of 36% of all the detected proteins were best matches to the SAR11 clade, and other abundant coastal microbial clades were also well represented, including the Roseobacter clade (17%), oligotrophic marine gammaproteobacteria group (6%), OM43 clade (1%). Viral origins were attributed to 2.5% of proteins. In contrast to oligotrophic waters, phosphate transporters were not highly detected in this nutrient-rich system. However, transporters for amino acids, taurine, polyamines and glutamine synthetase were among the most highly detected proteins, supporting predictions that carbon and nitrogen are more limiting than phosphate in this environment. Intriguingly, one of the highly detected proteins was methanol dehydrogenase originating from the OM43 clade, providing further support for recent reports that the metabolism of one-carbon compounds by these streamlined methylotrophs might be an important feature of coastal ocean biogeochemistry.

  12. Microbial Propionic Acid Production

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    R. Axayacatl Gonzalez-Garcia

    2017-05-01

    Full Text Available Propionic acid (propionate is a commercially valuable carboxylic acid produced through microbial fermentation. Propionic acid is mainly used in the food industry but has recently found applications in the cosmetic, plastics and pharmaceutical industries. Propionate can be produced via various metabolic pathways, which can be classified into three major groups: fermentative pathways, biosynthetic pathways, and amino acid catabolic pathways. The current review provides an in-depth description of the major metabolic routes for propionate production from an energy optimization perspective. Biological propionate production is limited by high downstream purification costs which can be addressed if the target yield, productivity and titre can be achieved. Genome shuffling combined with high throughput omics and metabolic engineering is providing new opportunities, and biological propionate production is likely to enter the market in the not so distant future. In order to realise the full potential of metabolic engineering and heterologous expression, however, a greater understanding of metabolic capabilities of the native producers, the fittest producers, is required.

  13. Microbial production of biovanillin

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    A. Converti

    2010-10-01

    Full Text Available This review aims at providing an overview on the microbial production of vanillin, a new alternative method for the production of this important flavor of the food industry, which has the potential to become economically competitive in the next future. After a brief description of the applications of vanillin in different industrial sectors and of its physicochemical properties, we described the traditional ways of providing vanillin, specifically extraction and chemical synthesis (mainly oxidation and compared them with the new biotechnological options, i.e., biotransformations of caffeic acid, veratraldehyde and mainly ferulic acid. In the second part of the review, emphasis has been addressed to the factors most influencing the bioproduction of vanillin, specifically the age of inoculum, pH, temperature, type of co-substrate, as well as the inhibitory effects exerted either by excess substrate or product. The final part of the work summarized the downstream processes and the related unit operations involved in the recovery of vanillin from the bioconversion medium.

  14. Microbial production of biovanillin.

    Science.gov (United States)

    Converti, A; Aliakbarian, B; Domínguez, J M; Bustos Vázquez, G; Perego, P

    2010-07-01

    This review aims at providing an overview on the microbial production of vanillin, a new alternative method for the production of this important flavor of the food industry, which has the potential to become economically competitive in the next future. After a brief description of the applications of vanillin in different industrial sectors and of its physicochemical properties, we described the traditional ways of providing vanillin, specifically extraction and chemical synthesis (mainly oxidation) and compared them with the new biotechnological options, i.e., biotransformations of caffeic acid, veratraldehyde and mainly ferulic acid. In the second part of the review, emphasis has been addressed to the factors most influencing the bioproduction of vanillin, specifically the age of inoculum, pH, temperature, type of co-substrate, as well as the inhibitory effects exerted either by excess substrate or product. The final part of the work summarized the downstream processes and the related unit operations involved in the recovery of vanillin from the bioconversion medium.

  15. Recombinant production of plant lectins in microbial systems for biomedical application – the frutalin case study

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    Carla eOliveira

    2014-08-01

    Full Text Available Frutalin is a homotetrameric partly-glycosylated alpha-D-galactose-binding lectin of biomedical interest from Artocarpus incisa (breadfruit seeds, belonging to the jacalin-related lectins family. As other plant lectins, frutalin is a heterogeneous mixture of several isoforms possibly with distinct biological activities. The main problem of using such lectins as biomedical tools is that batch-to-batch variation in isoforms content may lead to inconstant results. The production of lectins by recombinant means has the advantage of obtaining high amounts of proteins with defined amino-acid sequences and more precise properties. In this mini review, we provide the strategies followed to produce two different forms of frutalin in two different microbial systems: Escherichia coli and Pichia pastoris. The processing and functional properties of the recombinant frutalin obtained from these hosts are compared to those of frutalin extracted from breadfruit. Emphasis is given particularly to recombinant frutalin produced in P. pastoris, which showed a remarkable capacity as biomarker of human prostate cancer and as apoptosis-inducer of cancer cells. Recombinant frutalin production opens perspectives for its development as a new tool in human medicine.

  16. Recombinant production of plant lectins in microbial systems for biomedical application – the frutalin case study

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    Oliveira, Carla; Teixeira, José A.; Domingues, Lucília

    2014-01-01

    Frutalin is a homotetrameric partly glycosylated α-D-galactose-binding lectin of biomedical interest from Artocarpus incisa (breadfruit) seeds, belonging to the jacalin-related lectins family. As other plant lectins, frutalin is a heterogeneous mixture of several isoforms possibly with distinct biological activities. The main problem of using such lectins as biomedical tools is that “batch-to-batch” variation in isoforms content may lead to inconstant results. The production of lectins by recombinant means has the advantage of obtaining high amounts of proteins with defined amino-acid sequences and more precise properties. In this mini review, we provide the strategies followed to produce two different forms of frutalin in two different microbial systems: Escherichia coli and Pichia pastoris. The processing and functional properties of the recombinant frutalin obtained from these hosts are compared to those of frutalin extracted from breadfruit. Emphasis is given particularly to recombinant frutalin produced in P. pastoris, which showed a remarkable capacity as biomarker of human prostate cancer and as apoptosis-inducer of cancer cells. Recombinant frutalin production opens perspectives for its development as a new tool in human medicine. PMID:25152749

  17. Microbial production of gaseous hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, Hideo

    1987-10-20

    Microbial production of ethylene, isobutane and a saturated gaseous hydrocarbon mixture was described. Microbial ethylene production was studied with Penicillium digitatum IFO 9372 and a novel pathway of the ethylene biosynthesis through alpha-ketoglutarate was proposed. Rhodotorula minuta IFO 1102 was selected for the microbial production of isobutane and the interesting actions of L-leucine and L-phenylalanine for the isobutane production were found. It was finally presented about the microbial production of a saturated gaseous hydrocarbon mixture with Rhizopus japonicus IFO 4758 was described. A gas mixture was produced through a chemical reaction of SH compounds and some cellular component such as squalene under aerobic conditions. (4 figs, 7 tabs, 41 refs)

  18. Optimization studies of bio-hydrogen production in a coupled microbial electrolysis-dye sensitized solar cell system.

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    Ajayi, Folusho Francis; Kim, Kyoung-Yeol; Chae, Kyu-Jung; Choi, Mi-Jin; Chang, In Seop; Kim, In S

    2010-03-01

    Bio-hydrogen production in light-assisted microbial electrolysis cell (MEC) with a dye sensitized solar cell (DSSC) was optimized by connecting multiple MECs to a single dye (N719) sensitized solar cell (V(OC) approx. 0.7 V). Hydrogen production occurred simultaneously in all the connected MECs when the solar cell was irradiated with light. The amount of hydrogen produced in each MEC depends on the activity of the microbial catalyst on their anode. Substrate (acetate) to hydrogen conversion efficiencies ranging from 42% to 65% were obtained from the reactors during the experiment. A moderate light intensity of 430 W m(-2) was sufficient for hydrogen production in the coupled MEC-DSSC. A higher light intensity of 915 W m(-2), as well as an increase in substrate concentration, did not show any improvement in the current density due to limitation caused by the rate of microbial oxidation on the anode. A significant reduction in the surface area of the connected DSSC only showed a slight effect on current density in the coupled MEC-DSSC system when irradiated with light.

  19. Soluble microbial products (SMPs release in activated sludge systems: a review

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    Azami Hamed

    2012-12-01

    Full Text Available Abstract This review discusses the characterization, production and implications of soluble microbial products (SMPs in biological wastewater treatment. The precise definition of SMPs is open to talk about, but is currently regarded as “the pool of organic compounds that are released into solution from substrate metabolism and biomass decay”'. Some of the SMPs have been identified as humic acids, polysaccharides, proteins, amino acids, antibiotics, extracellular enzymes and structural components of cells and products of energy metabolism. They adversely affect the kinetic activity, flocculating and settling properties of sludge. This review outlines some important findings with regard to biodegradability and treatability of SMPs and also the effect of process parameters on their production. As SMPs are produced during biological treatment process, their trace amounts normally remain in the effluent that defines the highest COD removal efficiency. Their presence in effluent represents a high potential risk of toxic by-product formation during chlorine disinfection. Studies have indicated that among all wastewater post-treatment processes, the adsorption by granular activated carbon combined with biologically induced degradation is the most effective method for removal of SMPs. However, it may be concludes that the knowledge regarding SMPs is still under progress and more work is required to fully understand their contribution to the treatment process.

  20. Soluble Microbial Products (SMPs Release in Activated Sludge Systems: a Review

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    Hamed Azami

    2012-12-01

    Full Text Available This review discusses the characterization, production and implications of soluble microbial products (SMPs in biological wastewater treatment. The precise definition of SMPs is open to talk about, but is currently regarded as “the pool of organic compounds that are released into solution from substrate metabolism and biomass decay”'.Some of the SMPs have been identified as humic acids, olysaccharides, proteins, amino acids, antibiotics,extracellular enzymes and structural components of cells and products of energy metabolism. They adversely affect the kinetic activity, flocculating and settling properties of sludge. This review outlines some important findings with regard to biodegradability and treatability of SMPs and also the effect of process parameters on their production.As SMPs are produced during biological treatment process, their trace amounts normally remain in the effluent that defines the highest COD removal efficiency. Their presence in effluent represents a high potential risk of toxic by-product formation during chlorine disinfection. Studies have indicated that among all wastewaterpost-treatment processes, the adsorption by granular activated carbon combined with biologically induced degradation is the most effective method for removal of SMPs. However, it may be concludes that the knowledge regarding SMPs is still under progress and more work is required to fully understand their contribution to the treatment process.

  1. Microbial production of natural and non-natural flavonoids: Pathway engineering, directed evolution and systems/synthetic biology.

    Science.gov (United States)

    Pandey, Ramesh Prasad; Parajuli, Prakash; Koffas, Mattheos A G; Sohng, Jae Kyung

    2016-01-01

    In this review, we address recent advances made in pathway engineering, directed evolution, and systems/synthetic biology approaches employed in the production and modification of flavonoids from microbial cells. The review is divided into two major parts. In the first, various metabolic engineering and system/synthetic biology approaches used for production of flavonoids and derivatives are discussed broadly. All the manipulations/engineering accomplished on the microorganisms since 2000 are described in detail along with the biosynthetic pathway enzymes, their sources, structures of the compounds, and yield of each product. In the second part of the review, post-modifications of flavonoids by four major reactions, namely glycosylations, methylations, hydroxylations and prenylations using recombinant strains are described. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. The theoretical framework of agent based monitoring for use in the production of gellan gum in a microbial fermentation system

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    Eleni Mangina

    2003-06-01

    Full Text Available This paper introduces the application of an agent-based software system for monitoring the process of gellan gum production. Gellan gum (biopolymer is produced in industrial scale in bioreactors (sealed vessels where the microbial culture is grown in a liquid fermentation medium under controlled environmental conditions (temperature, pH, aeration and agitation. The multi agent system will view the monitoring problem as the interaction of simple independent software entities, for effective use of the available data. The outcome of this agent – based solution will include the automatic on-line data acquisition and correlation of the most important parameters. Within such a dynamic process, like the gellan gum production, certan parameters (such as biomass, gellan and glucose concentration change continuously and have to be measured and controlled. Also automatic knowledge derivation from past cases through the multi agent software system can be of future benefit.

  3. Biological hydrogen production in continuous stirred tank reactor systems with suspended and attached microbial growth

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    Ren, Nan-Qi; Tang, Jing; Liu, Bing-Feng; Guo, Wan-Qian [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, No.202 Haihe Road, Harbin 150090 (China)

    2010-04-15

    Fermentative H{sub 2} production in continuous stirred tank reactor (CSTR) system with bacteria attached onto granular activated carbon (GAC) was designed to produce H{sub 2} continuously. The H{sub 2} production performances of CSTR with suspended and attached-sludge from molasses were examined and compared at various organic loading rates (8-40 g COD/L/d) at hydraulic retention time of 6 h under mesophilic conditions (35 C). Both reactor systems achieved ethanol-type fermentation in the pH ranges 4.5-4.8 and 3.8-4.4, respectively, while ORP ranges from -450 to -470 mV and from -330 to -350 mV, respectively. The hydrogen production rate in the attached system was higher compared to that of the suspended system (9.72 and 6.65 L/d/L, respectively) while specific hydrogen production rate of 5.13 L/g VSS/d was higher in the suspended system. The attached-sludge CSTR is more stable than the suspended-sludge CSTR with regard to hydrogen production, pH, substrate utilization efficiency and metabolic products (e.g., volatile fatty acids and ethanol) during the whole test. (author)

  4. Microbial inputs in coffee (Coffea arabica L.) production systems, southwestern Ethiopia

    OpenAIRE

    Muleta, Diriba

    2007-01-01

    Arabica coffee is the key cash crop and top mainstay of the Ethiopian economy and requires sustainable production methods. Southwestern natural forests, the site of this study, are believed to be the centre of origin and diversity for Coffea arabica and still harbour wild Arabica coffee that may serve as an important gene pool for future breeding. Cost reductions, sustainability and quality improvement are now the major priorities in coffee production systems and require organic growing of co...

  5. Microbial diversity on commercial eggs as affected by the production system. A first approach using PGM.

    Science.gov (United States)

    Neira, Carmen; Laca, Amanda; Laca, Adriana; Díaz, Mario

    2017-12-04

    A novel DNA-based technique (PGM) has been employed for first time to analyse commercial eggs with the advantage of allowing an exhaustive identification of the microbiota present. Eggs from two different production systems, i.e. a free range system and a cage system, were analysed. Twenty-one and twenty-two phyla were identified on the surface of cage system and free range system eggs, respectively. In both cases, Firmicutes was the dominant phylum (representing around 50% of total phyla), being found families frequently reported to be present in the intestinal microbiota of chickens or hens, such as Clostridiaceae, Ruminococcaceae and Lachnospiraceae. Additionally, other phyla and families not previously described in association with eggshells could also be identified in this work. Most of the potential pathogenic genera associated with eggs (Salmonella, Clostridium, Helicobacter, Pseudomonas and Staphylococcus) showed higher incidence in eggs coming from cage systems than in eggs coming from free range systems, although the abundance of these genera were very low in both cases (<5% of total bacteria). Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Approaches to the production and use of microbial transglutaminase in emulsified meat and vegetable systems

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    I. A. Glotova

    2017-01-01

    Full Text Available In the technology of traditional and new forms of food, the modification of structure of proteins is carry out in two opposite directions: the hydrolytic destruction of high-molecular polymers and the artificial creation of polymeric structures of high molecular mass. The transglutaminase preparations (protein-glutamine (-glutamyltransferase, EC 2.3.2.13, TG are used in practical work for realization of the second direction. The main mechanisms of action are polymerization reactions, which lead to a change in the hydrophobicity of protein molecules. The main catalyzed reactions are acyl transfer, binding between glutamine and lysine residues of proteins and deamination. The authors analyzed the approaches to the preparation, properties and studied the joint effect of temperature and pH on the activity of the commercial preparation Revada TG 11 with the application of an enzymatic colorimetric test. The authors studied combined stuffing systems based on beef, pork, poultry mechanical deboning, as well as replacing part of the raw material with protein-carbohydrate compositions with Revada TG 11. The results were used to develop simulated meat systems of biopolymer compositions (SMSBC, approximate in structure and properties to the gels formed by actin and myosin during extraction from myofibrils under the traditional technological processes of meat products production - maturation, salt curing, fine meat grinding. SMSBC includes lupine flour bio-activated by germination, a preparations of dietary fiber as well as a preparation of transglutaminase Revada TG 11. The protein components of the secondary raw materials during the processing of milk such as sodium caseinate, and also whey were used to balance the amino acid composition of the food systems. For practical use, the following options for SMSBC introducing into the composition of minced meat emulsions were recommended by the authors: in the form of hydrated biopolymer dispersion at cutting

  7. Development of optimal enzymatic and microbial conversion systems for biofuel production

    Science.gov (United States)

    Aramrueang, Natthiporn

    The increase in demand for fuels, along with the concerns over the depletion of fossil fuels and the environmental problems associated with the use of the petroleum-based fuels, has driven the exploitation of clean and renewable energy. Through a collaboration project with Mendota Bioenergy LLC to produce advanced biofuel from sugar beet and other locally grown crops in the Central Valley of California through demonstration and commercial-scale biorefineries, the present study focused on the investigation of selected potential biomass as biofuel feedstock and development of bioconversion systems for sustainable biofuel production. For an efficient biomass-to-biofuel conversion process, three important steps, which are central to this research, must be considered: feedstock characterization, enzymatic hydrolysis of the feedstock, and the bioconversion process. The first part of the research focused on the characterization of various lignocellulosic biomass as feedstocks and investigated their potential ethanol yields. Physical characteristics and chemical composition were analyzed for four sugar beet varieties, three melon varieties, tomato, Jose tall wheatgrass, wheat hay, and wheat straw. Melons and tomato are those products discarded by the growers or processors due to poor quality. The mass-based ethanol potential of each feedstock was determined based on the composition. The high sugar-containing feedstocks are sugar beet roots, melons, and tomato, containing 72%, 63%, and 42% average soluble sugars on a dry basis, respectively. Thus, for these crops, the soluble sugars are the main substrate for ethanol production. The potential ethanol yields, on average, for sugar beet roots, melons, and tomato are 591, 526, and 448 L ethanol/metric ton dry basis (d.b.), respectively. Lignocellulosic biomass, including Jose Tall wheatgrass and wheat straw, are composed primarily of cellulose (27-39% d.b.) and hemicellulose (26-30% d.b.). The ethanol yields from these

  8. Efficient solar-to-fuels production from a hybrid microbial-water-splitting catalyst system.

    Science.gov (United States)

    Torella, Joseph P; Gagliardi, Christopher J; Chen, Janice S; Bediako, D Kwabena; Colón, Brendan; Way, Jeffery C; Silver, Pamela A; Nocera, Daniel G

    2015-02-24

    Photovoltaic cells have considerable potential to satisfy future renewable-energy needs, but efficient and scalable methods of storing the intermittent electricity they produce are required for the large-scale implementation of solar energy. Current solar-to-fuels storage cycles based on water splitting produce hydrogen and oxygen, which are attractive fuels in principle but confront practical limitations from the current energy infrastructure that is based on liquid fuels. In this work, we report the development of a scalable, integrated bioelectrochemical system in which the bacterium Ralstonia eutropha is used to efficiently convert CO2, along with H2 and O2 produced from water splitting, into biomass and fusel alcohols. Water-splitting catalysis was performed using catalysts that are made of earth-abundant metals and enable low overpotential water splitting. In this integrated setup, equivalent solar-to-biomass yields of up to 3.2% of the thermodynamic maximum exceed that of most terrestrial plants. Moreover, engineering of R. eutropha enabled production of the fusel alcohol isopropanol at up to 216 mg/L, the highest bioelectrochemical fuel yield yet reported by >300%. This work demonstrates that catalysts of biotic and abiotic origin can be interfaced to achieve challenging chemical energy-to-fuels transformations.

  9. Biotechnological Processes in Microbial Amylase Production.

    Science.gov (United States)

    Gopinath, Subash C B; Anbu, Periasamy; Arshad, M K Md; Lakshmipriya, Thangavel; Voon, Chun Hong; Hashim, Uda; Chinni, Suresh V

    2017-01-01

    Amylase is an important and indispensable enzyme that plays a pivotal role in the field of biotechnology. It is produced mainly from microbial sources and is used in many industries. Industrial sectors with top-down and bottom-up approaches are currently focusing on improving microbial amylase production levels by implementing bioengineering technologies. The further support of energy consumption studies, such as those on thermodynamics, pinch technology, and environment-friendly technologies, has hastened the large-scale production of the enzyme. Herein, the importance of microbial (bacteria and fungi) amylase is discussed along with its production methods from the laboratory to industrial scales.

  10. Biotechnological Processes in Microbial Amylase Production

    Directory of Open Access Journals (Sweden)

    Subash C. B. Gopinath

    2017-01-01

    Full Text Available Amylase is an important and indispensable enzyme that plays a pivotal role in the field of biotechnology. It is produced mainly from microbial sources and is used in many industries. Industrial sectors with top-down and bottom-up approaches are currently focusing on improving microbial amylase production levels by implementing bioengineering technologies. The further support of energy consumption studies, such as those on thermodynamics, pinch technology, and environment-friendly technologies, has hastened the large-scale production of the enzyme. Herein, the importance of microbial (bacteria and fungi amylase is discussed along with its production methods from the laboratory to industrial scales.

  11. Opportunities and challenges for the sustainable production of structurally complex diterpenoids in recombinant microbial systems.

    Science.gov (United States)

    Kemper, Katarina; Hirte, Max; Reinbold, Markus; Fuchs, Monika; Brück, Thomas

    2017-01-01

    With over 50.000 identified compounds terpenes are the largest and most structurally diverse group of natural products. They are ubiquitous in bacteria, plants, animals and fungi, conducting several biological functions such as cell wall components or defense mechanisms. Industrial applications entail among others pharmaceuticals, food additives, vitamins, fragrances, fuels and fuel additives. Central building blocks of all terpenes are the isoprenoid compounds isopentenyl diphosphate and dimethylallyl diphosphate. Bacteria like Escherichia coli harbor a native metabolic pathway for these isoprenoids that is quite amenable for genetic engineering. Together with recombinant terpene biosynthesis modules, they are very suitable hosts for heterologous production of high value terpenes. Yet, in contrast to the number of extracted and characterized terpenes, little is known about the specific biosynthetic enzymes that are involved especially in the formation of highly functionalized compounds. Novel approaches discussed in this review include metabolic engineering as well as site-directed mutagenesis to expand the natural terpene landscape. Focusing mainly on the validation of successful integration of engineered biosynthetic pathways into optimized terpene producing Escherichia coli , this review shall give an insight in recent progresses regarding manipulation of mostly diterpene synthases.

  12. Opportunities and challenges for the sustainable production of structurally complex diterpenoids in recombinant microbial systems

    Directory of Open Access Journals (Sweden)

    Katarina Kemper

    2017-05-01

    Full Text Available With over 50.000 identified compounds terpenes are the largest and most structurally diverse group of natural products. They are ubiquitous in bacteria, plants, animals and fungi, conducting several biological functions such as cell wall components or defense mechanisms. Industrial applications entail among others pharmaceuticals, food additives, vitamins, fragrances, fuels and fuel additives. Central building blocks of all terpenes are the isoprenoid compounds isopentenyl diphosphate and dimethylallyl diphosphate. Bacteria like Escherichia coli harbor a native metabolic pathway for these isoprenoids that is quite amenable for genetic engineering. Together with recombinant terpene biosynthesis modules, they are very suitable hosts for heterologous production of high value terpenes. Yet, in contrast to the number of extracted and characterized terpenes, little is known about the specific biosynthetic enzymes that are involved especially in the formation of highly functionalized compounds. Novel approaches discussed in this review include metabolic engineering as well as site-directed mutagenesis to expand the natural terpene landscape. Focusing mainly on the validation of successful integration of engineered biosynthetic pathways into optimized terpene producing Escherichia coli, this review shall give an insight in recent progresses regarding manipulation of mostly diterpene synthases.

  13. Genome engineering for microbial natural product discovery.

    Science.gov (United States)

    Choi, Si-Sun; Katsuyama, Yohei; Bai, Linquan; Deng, Zixin; Ohnishi, Yasuo; Kim, Eung-Soo

    2018-03-03

    The discovery and development of microbial natural products (MNPs) have played pivotal roles in the fields of human medicine and its related biotechnology sectors over the past several decades. The post-genomic era has witnessed the development of microbial genome mining approaches to isolate previously unsuspected MNP biosynthetic gene clusters (BGCs) hidden in the genome, followed by various BGC awakening techniques to visualize compound production. Additional microbial genome engineering techniques have allowed higher MNP production titers, which could complement a traditional culture-based MNP chasing approach. Here, we describe recent developments in the MNP research paradigm, including microbial genome mining, NP BGC activation, and NP overproducing cell factory design. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Impacts of biostimulant products on the growth of wheat and the microbial communities of its rhizosphere under contrasted production systems

    OpenAIRE

    Nguyen, Minh; Bodson, Bernard; Colinet, Gilles; Jijakli, Haissam; Ongena, Marc; Vandenbol, Micheline; du Jardin, Patrick; Spaepen, Stijn; Delaplace, Pierre

    2014-01-01

    Plant growth-promoting rhizobacteria (PGPR) are one of the major biostimulant classes due to their ability to stimulate root growth, enhance mineral availability, and nutrient use efficiency in crops. PGPR-containing biostimulant products could therefore make agriculture more sustainable by reducing demand for chemical fertilizer and lessen their negative environmental impacts. The aim of this project is to screen PGPR strains to (1) enhance wheat fitness level (growth, photosynthesis efficie...

  15. Microbial amylases in the production of alcohol

    Energy Technology Data Exchange (ETDEWEB)

    Pieper, H J

    1970-01-01

    This book is based on experiments carried out in the experimental distillery of the University of Hohenheim on the use of microbial enzyme preparations for processing wheat and maize, with particular reference to comparison of green and cured malts. The subject is divided into the following chapters: introduction (pp. -14); raw materials (pp. 5-6); enzymic dextrinizing and saccharification agents (pp. 6-10); technology of alcohol production with microbial amylses (pp. 11-27); experiments into, results of and discussion on special problems of the mashing and fermentation process with reference to application of microbial amylases (pp. 28-45); Analytical methods (pp. 46-51); and Resume (pp. 5254).

  16. Enhancing microbial production of biofuels by expanding microbial metabolic pathways.

    Science.gov (United States)

    Yu, Ping; Chen, Xingge; Li, Peng

    2017-09-01

    Fatty acid, isoprenoid, and alcohol pathways have been successfully engineered to produce biofuels. By introducing three genes, atfA, adhE, and pdc, into Escherichia coli to expand fatty acid pathway, up to 1.28 g/L of fatty acid ethyl esters can be achieved. The isoprenoid pathway can be expanded to produce bisabolene with a high titer of 900 mg/L in Saccharomyces cerevisiae. Short- and long-chain alcohols can also be effectively biosynthesized by extending the carbon chain of ketoacids with an engineered "+1" alcohol pathway. Thus, it can be concluded that expanding microbial metabolic pathways has enormous potential for enhancing microbial production of biofuels for future industrial applications. However, some major challenges for microbial production of biofuels should be overcome to compete with traditional fossil fuels: lowering production costs, reducing the time required to construct genetic elements and to increase their predictability and reliability, and creating reusable parts with useful and predictable behavior. To address these challenges, several aspects should be further considered in future: mining and transformation of genetic elements related to metabolic pathways, assembling biofuel elements and coordinating their functions, enhancing the tolerance of host cells to biofuels, and creating modular subpathways that can be easily interconnected. © 2016 International Union of Biochemistry and Molecular Biology, Inc.

  17. Hydrogen production from microbial strains

    Science.gov (United States)

    Harwood, Caroline S; Rey, Federico E

    2012-09-18

    The present invention is directed to a method of screening microbe strains capable of generating hydrogen. This method involves inoculating one or more microbes in a sample containing cell culture medium to form an inoculated culture medium. The inoculated culture medium is then incubated under hydrogen producing conditions. Once incubating causes the inoculated culture medium to produce hydrogen, microbes in the culture medium are identified as candidate microbe strains capable of generating hydrogen. Methods of producing hydrogen using one or more of the microbial strains identified as well as the hydrogen producing strains themselves are also disclosed.

  18. Systems biology of Microbial Communities

    Energy Technology Data Exchange (ETDEWEB)

    Navid, A; Ghim, C; Fenley, A; Yoon, S; Lee, S; Almaas, E

    2008-04-11

    Microbes exist naturally in a wide range of environments, spanning the extremes of high acidity and high temperature to soil and the ocean, in communities where their interactions are significant. We present a practical discussion of three different approaches for modeling microbial communities: rate equations, individual-based modeling, and population dynamics. We illustrate the approaches with detailed examples. Each approach is best fit to different levels of system representation, and they have different needs for detailed biological input. Thus, this set of approaches is able to address the operation and function of microbial communities on a wide range of organizational levels.

  19. Gluconic Acid: Properties, Applications and Microbial Production

    Directory of Open Access Journals (Sweden)

    Sumitra Ramachandran

    2006-01-01

    Full Text Available Gluconic acid is a mild organic acid derived from glucose by a simple oxidation reaction. The reaction is facilitated by the enzyme glucose oxidase (fungi and glucose dehydrogenase (bacteria such as Gluconobacter. Microbial production of gluconic acid is the preferred method and it dates back to several decades. The most studied and widely used fermentation process involves the fungus Aspergillus niger. Gluconic acid and its derivatives, the principal being sodium gluconate, have wide applications in food and pharmaceutical industry. This article gives a review of microbial gluconic acid production, its properties and applications.

  20. Microbial reverse-electrodialysis chemical-production cell for acid and alkali production

    KAUST Repository

    Zhu, Xiuping; Hatzell, Marta C.; Cusick, Roland D.; Logan, Bruce E.

    2013-01-01

    A new type of bioelectrochemical system, called a microbial reverse-electrodialysis chemical-production cell (MRCC), was developed to produce acid and alkali using energy derived from organic matter (acetate) and salinity gradients (NaCl solutions

  1. 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.

  2. Laser engineering of microbial systems

    Science.gov (United States)

    Yusupov, V. I.; Gorlenko, M. V.; Cheptsov, V. S.; Minaev, N. V.; Churbanova, E. S.; Zhigarkov, V. S.; Chutko, E. A.; Evlashin, S. A.; Chichkov, B. N.; Bagratashvili, V. N.

    2018-06-01

    A technology of laser engineering of microbial systems (LEMS) based on the method of laser-induced transfer of heterogeneous mixtures containing microorganisms (laser bioprinting) is described. This technology involves laser printing of soil microparticles by focusing near-infrared laser pulses on a specially prepared gel/soil mixture spread onto a gold-coated glass plate. The optimal range of laser energies from the point of view of the formation of stable jets and droplets with minimal negative impact on living systems of giant accelerations, laser pulse irradiation, and Au nanoparticles was found. Microsamples of soil were printed on glucose-peptone-yeast agar plates to estimate the LEMS process influence on structural and morphological microbial diversity. The obtained results were compared with traditionally treated soil samples. It was shown that LEMS technology allows significantly increasing the biodiversity of printed organisms and is effective for isolating rare or unculturable microorganisms.

  3. Microbial ecology measurement system

    Science.gov (United States)

    1972-01-01

    The sensitivity and potential rapidity of the PIA test that was demonstrated during the feasibility study warranted continuing the effort to examine the possibility of adapting this test to an automated procedure that could be used during manned missions. The effort during this program has optimized the test conditions for two important respiratory pathogens, influenza virus and Mycoplasma pneumoniae, developed a laboratory model automated detection system, and investigated a group antigen concept for virus detection. Preliminary tests on the handling of oropharygeal clinical samples for PIA testing were performed using the adenovirus system. The results obtained indicated that the PIA signal is reduced in positive samples and is increased in negative samples. Treatment with cysteine appeared to reduce nonspecific agglutination in negative samples but did not maintain the signal in positive samples.

  4. Microbial production of value-added nutraceuticals.

    Science.gov (United States)

    Wang, Jian; Guleria, Sanjay; Koffas, Mattheos Ag; Yan, Yajun

    2016-02-01

    Nutraceuticals are important natural bioactive compounds that confer health-promoting and medical benefits to humans. Globally growing demands for value-added nutraceuticals for prevention and treatment of human diseases have rendered nutraceuticals a multi-billion dollar market. However, supply limitations and extraction difficulties from natural sources such as plants, animals or fungi, restrict the large-scale use of nutraceuticals. Metabolic engineering via microbial production platforms has been advanced as an eco-friendly alternative approach for production of value-added nutraceuticals from simple carbon sources. Microbial platforms like the most widely used Escherichia coli and Saccharomyces cerevisiae have been engineered as versatile cell factories for production of diverse and complex value-added chemicals such as phytochemicals, prebiotics, polysaccaharides and poly amino acids. This review highlights the recent progresses in biological production of value-added nutraceuticals via metabolic engineering approaches. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Microbial Heat Recovery Cell (MHRC) System Concept

    Energy Technology Data Exchange (ETDEWEB)

    None

    2017-09-01

    This factsheet describes a project that aimed to develop a microbial heat recovery cell (MHRC) system that combines a microbial reverse electrodialysis technology with waste heat recovery to convert industrial effluents into electricity and hydrogen.

  6. Antimutagenesis in microbial systems

    International Nuclear Information System (INIS)

    Clarke, C.H.; Shankel, D.M.

    1975-01-01

    There is shown to be a clear need to repeat several studies employing mutations involving known types of base-pair changes. It will be of obvious advantage in some instances to test for antimutagenic effects of chemicals in pairs of strains having and lacking a single well-defined repair function. The extension of antimutagenesis studies from phage and bacterial systems into eukaryotic systems is already taking place. Caution is also necessary in interpreting the antimutagenic effects of radiation-sensitive mutations. Reduction or abolition of mutability in a radiation-sensitive strain need not imply that an error-prone repair gene function is directly implicated in mutagenesis. Known antimutagens are, like known mutagens, so chemically diverse that a search for new types cannot logically be confined only to a few classes of compounds. If naturally occurring antimutagens are one of the normal regulators of spontaneous and induced mutation frequencies, then one might expect to be able to test this hypothesis by a biochemical analysis of some classes of mutators and mutagen hypermutable mutants. Mutators of several types are well known in several microorganisms, and uv hypermutable (hm) mutants have been described by Drake in phage T4, and 2-aminopurine hypermutable mutants have been isolated in E. coli B/r by Burr and Clarke (unpublished data). To date none of these has been investigated for, or shown to be lacking in, an endogenous antimutagen. It would be most useful if antimutagens should be found which strongly counteract the mutagenic activities of at least some environmental mutagens, particularly those having desirable pharmacological uses. Antimutagens have already been used, apparently successfully, as adjuvants in chemotherapy of patients in an attempt to reduce the frequency of occurrence of spontaneous antibiotic-resistant bacterial variants. They might also have some practical use in cancer chemotherapy or prevention. (U.S.)

  7. Genomic Prospecting for Microbial Biodiesel Production

    Energy Technology Data Exchange (ETDEWEB)

    Lykidis, Athanasios; Lykidis, Athanasios; Ivanova, Natalia

    2008-03-20

    Biodiesel is defined as fatty acid mono-alkylesters and is produced from triacylglycerols. In the current article we provide an overview of the structure, diversity and regulation of the metabolic pathways leading to intracellular fatty acid and triacylglycerol accumulation in three types of organisms (bacteria, algae and fungi) of potential biotechnological interest and discuss possible intervention points to increase the cellular lipid content. The key steps that regulate carbon allocation and distribution in lipids include the formation of malonyl-CoA, the synthesis of fatty acids and their attachment onto the glycerol backbone, and the formation of triacylglycerols. The lipid biosynthetic genes and pathways are largely known for select model organisms. Comparative genomics allows the examination of these pathways in organisms of biotechnological interest and reveals the evolution of divergent and yet uncharacterized regulatory mechanisms. Utilization of microbial systems for triacylglycerol and fatty acid production is in its infancy; however, genomic information and technologies combined with synthetic biology concepts provide the opportunity to further exploit microbes for the competitive production of biodiesel.

  8. Bioethanol production from cassava peels using different microbial ...

    African Journals Online (AJOL)

    Bioethanol production from cassava peels using different microbial inoculants. ... Log in or Register to get access to full text downloads. ... Abstract. The potential of bioethanol production using different microbial inoculants for the simultaneous ...

  9. Electricity production and microbial characterization of thermophilic microbial fuel cells.

    Science.gov (United States)

    Dai, Kun; Wen, Jun-Li; Zhang, Fang; Ma, Xi-Wen; Cui, Xiang-Yu; Zhang, Qi; Zhao, Ting-Jia; Zeng, Raymond J

    2017-11-01

    Thermophilic microbial fuel cell (TMFC) offers many benefits, but the investigations on the diversity of exoelectrogenic bacteria are scarce. In this study, a two-chamber TMFC was constructed using ethanol as an electron donor, and the microbial dynamics were analyzed by high-throughput sequencing and 16S rRNA clone-library sequencing. The open-circuit potential of TMFC was approximately 650mV, while the maximum voltage was around 550mV. The maximum power density was 437mW/m 2 , and the columbic efficiency in this work was 20.5±6.0%. The Firmicutes bacteria, related to the uncultured bacterium clone A55_D21_H_B_C01 with a similarity of 99%, accounted for 90.9% of all bacteria in the TMFC biofilm. This unknown bacterium has the potential to become a new thermophilic exoelectrogenic bacterium that is yet to be cultured. The development of TMFC-involved biotechnologies will be beneficial for the production of valuable chemicals and generation of energy in the future. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Perspectives of microbial oils for biodiesel production

    Energy Technology Data Exchange (ETDEWEB)

    Li Qiang; Du Wei; Liu Dehua [Tsinghua Univ., Beijing (China). Dept. of Chemical Engineering

    2008-10-15

    Biodiesel has become more attractive recently because of its environmental benefits, and the fact that it is made from renewable resources. Generally speaking, biodiesel is prepared through transesterification of vegetable oils or animal fats with short chain alcohols. However, the lack of oil feedstocks limits the large-scale development of biodiesel to some extent. Recently, much attention has been paid to the development of microbial, oils and it has been found that many microorganisms, such as algae, yeast, bacteria, and fungi, have the ability to accumulate oils under some special cultivation conditions. Compared to other plant oils, microbial oils have many advantages, such as short life cycle, less labor required, less affection by venue, season and climate, and easier to scale up. With the rapid expansion of biodiesel, microbial oils might become one of potential oil feedstocks for biodiesel production in the future, though there are many works associated with microorganisms producing oils need to be carried out further. This review is covering the related research about different oleaginous microorganisms producing oils, and the prospects of such microbial oils used for biodiesel production are also discussed. (orig.)

  11. Microbial production of citric acid

    Directory of Open Access Journals (Sweden)

    Luciana P. S Vandenberghe

    1999-01-01

    Full Text Available Citric acid is the most important organic acid produced in tonnage and is extensively used in food and pharmaceutical industries. It is produced mainly by submerged fermentation using Aspergillus niger or Candida sp. from different sources of carbohydrates, such as molasses and starch based media. However, other fermentation techniques, e.g. solid state fermentation and surface fermentation, and alternative sources of carbon such as agro-industrial residues have been intensively studied showing great perspective to its production. This paper reviews recent developments on citric acid production by presenting a brief summary of the subject, describing micro-organisms, production techniques, and substrates, etc.O ácido cítrico é o ácido mais produzido em termos de tonagem e é extensivamente utilizado pelas indústrias alimentícia e farmacêutica. É produzido principalmente por fermentação submersa utilizando o fungo Aspergillus niger e leveduras do gênero Candida sp. à partir de diferentes fontes de carbono, como a glicose e meios à base de amido. No entanto, outras técnicas de fermentação, e.g. fermentação no estado sólido e em superfície, e fontes alternativas de carbono tem sido intensamente estudadas mostrando grande perspectivas para o processo. O presente trabalho apresenta um resumo dos últimos avanços sobre a produção do ácido cítrico, descrevendo de maneira sucinta os trabalhos mais recentes, descrevendo microrganismos, técnicas de produção e substratos empregados, etc.

  12. Microbial Glycosidases for Wine Production

    Directory of Open Access Journals (Sweden)

    Sergi Maicas

    2016-08-01

    Full Text Available Winemaking is a complex process involving the interaction of different microbes. The two main groups of microorganisms involved are yeasts and bacteria. The yeasts present in spontaneous fermentation may be divided into two groups: the Saccharomyces yeasts, particularly S. cerevisiae; and the non-Saccharomyces yeasts, which include members of the genera Rhodotorula, Pichia, Candida, Debaryomyces, Metschtnikowia, Hansenula, and Hanseniaspora. S. cerevisiae yeasts are able to convert sugar into ethanol and CO2 via fermentation. They have been used by humans for thousands of years for the production of fermented beverages and foods, including wine. Their enzymes provide interesting organoleptic characteristics in wine. Glycosidases with oenological implications have been widely reported in yeasts, bacteria, and fungi. β-Glucosidase activity is involved in the release of terpenes to wine, thus contributing to varietal aroma. α-Rhamnosidase, α-arabinosidase, or β-apiosidase activities have also been reported to contribute to the wine production process. Oenococcus oeni (a lactic acid bacteria present in wine also has numerous glycosidases, and their activities contribute to the liberation of several aromatic compounds which contribute to floral and fruity wine characteristics.

  13. Recent advances in microbial production of fuels and chemicals using tools and strategies of systems metabolic engineering

    DEFF Research Database (Denmark)

    Cho, Changhee; Choi, So Young; Luo, Zi Wei

    2015-01-01

    The advent of various systems metabolic engineering tools and strategies has enabled more sophisticated engineering of microorganisms for the production of industrially useful fuels and chemicals. Advances in systems metabolic engineering have been made in overproducing natural chemicals...... and producing novel non-natural chemicals. In this paper, we review the tools and strategies of systems metabolic engineering employed for the development of microorganisms for the production of various industrially useful chemicals belonging to fuels, building block chemicals, and specialty chemicals......, in particular focusing on those reported in the last three years. It was aimed at providing the current landscape of systems metabolic engineering and suggesting directions to address future challenges towards successfully establishing processes for the bio-based production of fuels and chemicals from renewable...

  14. Recent advances in microbial production of fuels and chemicals using tools and strategies of systems metabolic engineering.

    Science.gov (United States)

    Cho, Changhee; Choi, So Young; Luo, Zi Wei; Lee, Sang Yup

    2015-11-15

    The advent of various systems metabolic engineering tools and strategies has enabled more sophisticated engineering of microorganisms for the production of industrially useful fuels and chemicals. Advances in systems metabolic engineering have been made in overproducing natural chemicals and producing novel non-natural chemicals. In this paper, we review the tools and strategies of systems metabolic engineering employed for the development of microorganisms for the production of various industrially useful chemicals belonging to fuels, building block chemicals, and specialty chemicals, in particular focusing on those reported in the last three years. It was aimed at providing the current landscape of systems metabolic engineering and suggesting directions to address future challenges towards successfully establishing processes for the bio-based production of fuels and chemicals from renewable resources. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Optimization of Microbial Elastase Production

    International Nuclear Information System (INIS)

    Abd EI-Aziz, A.B.; Hassan, A.A.

    2010-01-01

    The extra cellular proteases (caseinase, gelatinase and elastase) and hemolytic activities of the tested microorganisms on agar plates were detected, using different substrates (gelatin, casein, hemoglobin and elastin).The proteolytic activities were detected only from Pseudomonas aeruginosa, Prevotella bivius, Bacillus subtilis and Micrococcus luteus. The production of elastase by Bacillus subtilis (has low hemolysins activity) at various temperatures (30 degree C - 37 degree C) and at exposure to different doses of gamma irradiation (0.25-1.0 kGy) was investigated in shake flask. The results indicated that the incubation temperature 37 degree C was the optimum for cell growth at earlier stage; while maximum elastase activity was obtained when the cells were cultivated at 30 degree C and irradiation dose level of 0.75 kGy. The effects of temperature, substrate content, elastase concentration, ph and different metals ions on elastolysis were investigated as well the elastase amino acids composition was detected by using amino acids analyzer

  16. Microbial granulation for lactic acid production

    DEFF Research Database (Denmark)

    Kim, Dong-Hoon; Lee, Mo-Kwon; Hwang, Yuhoon

    2016-01-01

    This work investigated the formation of microbial granules to boost the productivity of lactic acid (LA). The flocculated form of LA-producing microbial consortium, dominated by Lactobacillus sp. (91.5% of total sequence), was initially obtained in a continuous stirred-tank reactor (CSTR), which...... increased, reaching 67 g L-fermenter−1h−1 at HRT 0.17 h. The size of LA-producing granules and hydrophobicity gradually increased with decrease in HRT, reaching 6.0 mm and 60%, respectively. These biogranules were also found to have high settling velocities and low porosities, ranging 2.69-4.73 cm s−1 and 0...

  17. Microbial production of hyaluronic acid: current state, challenges, and perspectives

    Directory of Open Access Journals (Sweden)

    Liu Long

    2011-11-01

    Full Text Available Abstract Hyaluronic acid (HA is a natural and linear polymer composed of repeating disaccharide units of β-1, 3-N-acetyl glucosamine and β-1, 4-glucuronic acid with a molecular weight up to 6 million Daltons. With excellent viscoelasticity, high moisture retention capacity, and high biocompatibility, HA finds a wide-range of applications in medicine, cosmetics, and nutraceuticals. Traditionally HA was extracted from rooster combs, and now it is mainly produced via streptococcal fermentation. Recently the production of HA via recombinant systems has received increasing interest due to the avoidance of potential toxins. This work summarizes the research history and current commercial market of HA, and then deeply analyzes the current state of microbial production of HA by Streptococcus zooepidemicus and recombinant systems, and finally discusses the challenges facing microbial HA production and proposes several research outlines to meet the challenges.

  18. Microbials for the production of monoclonal antibodies and antibody fragments.

    Science.gov (United States)

    Spadiut, Oliver; Capone, Simona; Krainer, Florian; Glieder, Anton; Herwig, Christoph

    2014-01-01

    Monoclonal antibodies (mAbs) and antibody fragments represent the most important biopharmaceutical products today. Because full length antibodies are glycosylated, mammalian cells, which allow human-like N-glycosylation, are currently used for their production. However, mammalian cells have several drawbacks when it comes to bioprocessing and scale-up, resulting in long processing times and elevated costs. By contrast, antibody fragments, that are not glycosylated but still exhibit antigen binding properties, can be produced in microbial organisms, which are easy to manipulate and cultivate. In this review, we summarize recent advances in the expression systems, strain engineering, and production processes for the three main microbials used in antibody and antibody fragment production, namely Saccharomyces cerevisiae, Pichia pastoris, and Escherichia coli. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Perspective for Aquaponic Systems: "Omic" Technologies for Microbial Community Analysis.

    Science.gov (United States)

    Munguia-Fragozo, Perla; Alatorre-Jacome, Oscar; Rico-Garcia, Enrique; Torres-Pacheco, Irineo; Cruz-Hernandez, Andres; Ocampo-Velazquez, Rosalia V; Garcia-Trejo, Juan F; Guevara-Gonzalez, Ramon G

    2015-01-01

    Aquaponics is the combined production of aquaculture and hydroponics, connected by a water recirculation system. In this productive system, the microbial community is responsible for carrying out the nutrient dynamics between the components. The nutrimental transformations mainly consist in the transformation of chemical species from toxic compounds into available nutrients. In this particular field, the microbial research, the "Omic" technologies will allow a broader scope of studies about a current microbial profile inside aquaponics community, even in those species that currently are unculturable. This approach can also be useful to understand complex interactions of living components in the system. Until now, the analog studies were made to set up the microbial characterization on recirculation aquaculture systems (RAS). However, microbial community composition of aquaponics is still unknown. "Omic" technologies like metagenomic can help to reveal taxonomic diversity. The perspectives are also to begin the first attempts to sketch the functional diversity inside aquaponic systems and its ecological relationships. The knowledge of the emergent properties inside the microbial community, as well as the understanding of the biosynthesis pathways, can derive in future biotechnological applications. Thus, the aim of this review is to show potential applications of current "Omic" tools to characterize the microbial community in aquaponic systems.

  20. Production of hydrogen by microbial fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Roychowdhury, S.; Cox, D.; Levandowsky, M.

    1988-01-01

    Production of hydrogen by defined and undefined bacterial cultures was studied, using pure sugars (glucose and maltose) or natural sources rich in either pure sugars or polysaccharides. The latter included sugar cane juice, corn pulp (enzymatically treated or untreated), and enzymatically treated paper. Mixed microbial flora from sewage and landfill sediments, as well as pure and mixed cultures of known coliform bacteria produced mixtures of hydrogen and carbon dioxide at 37/sup 0/C and 55/sup 0/C, with hydrogen concentrations as high as 87%. In the case of the pure glucose substrate, an average yield of 0.7 mol hydrogen per mol glucose was obtained.

  1. Advances and bottlenecks in microbial hydrogen production.

    Science.gov (United States)

    Stephen, Alan J; Archer, Sophie A; Orozco, Rafael L; Macaskie, Lynne E

    2017-09-01

    Biological production of hydrogen is poised to become a significant player in the future energy mix. This review highlights recent advances and bottlenecks in various approaches to biohydrogen processes, often in concert with management of organic wastes or waste CO 2 . Some key bottlenecks are highlighted in terms of the overall energy balance of the process and highlighting the need for economic and environmental life cycle analyses with regard also to socio-economic and geographical issues. © 2017 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  2. Biosynthesis of fluorescent CdS nanocrystals with semiconductor properties: Comparison of microbial and plant production systems.

    Science.gov (United States)

    Al-Shalabi, Zahwa; Doran, Pauline M

    2016-04-10

    This study investigated fission yeast (Schizosaccharomyces pombe) and hairy roots of tomato (Solanum lycopersicum) as in vitro production vehicles for biological synthesis of CdS quantum dots. Cd added during the mid-growth phase of the cultures was detoxified within the biomass into inorganic sulphide-containing complexes with the quantum confinement properties of semiconductor nanocrystals. Significant differences were found between the two host systems in terms of nanoparticle production kinetics, yield and quality. The much slower growth rate of hairy roots compared with yeast is a disadvantage for commercial scaled-up production. Nanoparticle extraction from the biomass was less effective for the roots: 19% of the Cd present in the hairy roots was recovered after extraction compared with 34% for the yeast. The overall yield of CdS quantum dots was also lower for the roots: relative to the amount of Cd taken up into the biomass, 8.5% was recovered in yeast gel filtration fractions exhibiting quantum dot properties whereas the result for hairy roots was only 0.99%. Yeast-produced CdS crystallites were somewhat smaller with diameters of approximately 2-6 nm compared with those of 4-10nm obtained from the roots. The average ratio of inorganic sulphide to Cd for the purified and size-fractionated particles was 0.44 for the yeast and 1.6 for the hairy roots. Despite the limitations associated with hairy roots in terms of culture kinetics and product yield, this system produced CdS nanoparticles with enhanced photostability and 3.7-13-fold higher fluorescence quantum efficiency compared with those generated by yeast. This work demonstrates that the choice of cellular host can have a significant effect on nanoparticle functional properties as well as on the bioprocessing aspects of biological quantum dot synthesis. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Problems with the microbial production of butanol.

    Science.gov (United States)

    Zheng, Yan-Ning; Li, Liang-Zhi; Xian, Mo; Ma, Yu-Jiu; Yang, Jian-Ming; Xu, Xin; He, Dong-Zhi

    2009-09-01

    With the incessant fluctuations in oil prices and increasing stress from environmental pollution, renewed attention is being paid to the microbial production of biofuels from renewable sources. As a gasoline substitute, butanol has advantages over traditional fuel ethanol in terms of energy density and hygroscopicity. A variety of cheap substrates have been successfully applied in the production of biobutanol, highlighting the commercial potential of biobutanol development. In this review, in order to better understand the process of acetone-butanol-ethanol production, traditional clostridia fermentation is discussed. Sporulation is probably induced by solvent formation, and the molecular mechanism leading to the initiation of sporulation and solventogenesis is also investigated. Different strategies are employed in the metabolic engineering of clostridia that aim to enhancing solvent production, improve selectivity for butanol production, and increase the tolerance of clostridia to solvents. However, it will be hard to make breakthroughs in the metabolic engineering of clostridia for butanol production without gaining a deeper understanding of the genetic background of clostridia and developing more efficient genetic tools for clostridia. Therefore, increasing attention has been paid to the metabolic engineering of E. coli for butanol production. The importation and expression of a non-clostridial butanol-producing pathway in E. coli is probably the most promising strategy for butanol biosynthesis. Due to the lower butanol titers in the fermentation broth, simultaneous fermentation and product removal techniques have been developed to reduce the cost of butanol recovery. Gas stripping is the best technique for butanol recovery found so far.

  4. Manufacturing of recombinant therapeutic proteins in microbial systems.

    Science.gov (United States)

    Graumann, Klaus; Premstaller, Andreas

    2006-02-01

    Recombinant therapeutic proteins have gained enormous importance for clinical applications. The first recombinant products have been produced in E. coli more than 20 years ago. Although with the advent of antibody-based therapeutics mammalian expression systems have experienced a major boost, microbial expression systems continue to be widely used in industry. Their intrinsic advantages, such as rapid growth, high yields and ease of manipulation, make them the premier choice for expression of non-glycosylated peptides and proteins. Innovative product classes such as antibody fragments or alternative binding molecules will further expand the use of microbial systems. Even more, novel, engineered production hosts and integrated technology platforms hold enormous potential for future applications. This review summarizes current applications and trends for development, production and analytical characterization of recombinant therapeutic proteins in microbial systems.

  5. Microbial lipases: Production, properties and biotechnological applications

    Directory of Open Access Journals (Sweden)

    Josana Maria Messias

    2011-09-01

    Full Text Available Lipases belong to the group of hydrolases that catalyze the hydrolysis of triacylglycerol lipids to free fatty acids and glycerol. They have significant potential biotechnological applications in catalyzing organic synthesis reactions in non-aqueous solvents using simplified procedures resulting in conversions of high yields. Lipase production has conventionally been performed by submerged fermentation; however, solid-state fermentation processes have been prominent when residues are used as substrates because they serve as low-cost nutrient sources. Microbial lipases can be used as additives in foods to modify and enhance organoleptic properties, as well as in detergents to hydrolyse fats in the treatment of oily effluents, and also have value for pharmaceutical, cosmetic, agrochemical, and oil chemical industries. More recently, they are used in transesterification reactions to convert plant seed oils into biodiesel. The objective of this work was to review the published literature on the production, properties and applications of microbial lipases, and its biotechnological role in producing biodiesel.

  6. Microbial electrolysis cells as innovative technology for hydrogen production

    International Nuclear Information System (INIS)

    Chorbadzhiyska, Elitsa; Hristov, Georgi; Mitov, Mario; Hubenova, Yolina

    2011-01-01

    Hydrogen production is becoming increasingly important in view of using hydrogen in fuel cells. However, most of the production of hydrogen so far comes from the combustion of fossil fuels and water electrolysis. Microbial Electrolysis Cell (MEC), also known as Bioelectrochemically Assisted Microbial Reactor, is an ecologically clean, renewable and innovative technology for hydrogen production. Microbial electrolysis cells produce hydrogen mainly from waste biomass assisted by various bacteria strains. The principle of MECs and their constructional elements are reviewed and discussed. Keywords: microbial Electrolysis Cells, hydrogen production, waste biomass purification

  7. Fermentative hydrogen production by microbial consortium

    Energy Technology Data Exchange (ETDEWEB)

    Maintinguer, Sandra I.; Fernandes, Bruna S.; Duarte, Iolanda C.S.; Saavedra, Nora Katia; Adorno, M. Angela T.; Varesche, M. Bernadete [Department of Hydraulics and Sanitation, School of Engineering of Sao Carlos, University of Sao Paulo, Av. Trabalhador Sao-carlense, 400, 13566-590 Sao Carlos-SP (Brazil)

    2008-08-15

    Heat pre-treatment of the inoculum associated to the pH control was applied to select hydrogen-producing bacteria and endospores-forming bacteria. The source of inoculum to the heat pre-treatment was from a UASB reactor used in the slaughterhouse waste treatment. The molecular biology analyses indicated that the microbial consortium presented microorganisms affiliated with Enterobacter cloacae (97% and 98%), Clostridium sp. (98%) and Clostridium acetobutyricum (96%), recognized as H{sub 2} and volatile acids' producers. The following assays were carried out in batch reactors in order to verify the efficiencies of sucrose conversion to H{sub 2} by the microbial consortium: (1) 630.0 mg sucrose/L, (2) 1184.0 mg sucrose/L, (3) 1816.0 mg sucrose/L and (4) 4128.0 mg sucrose/L. The subsequent yields were obtained as follows: 15% (1.2 mol H{sub 2}/mol sucrose), 20% (1.6 mol H{sub 2}/mol sucrose), 15% (1.2 mol H{sub 2}/mol sucrose) and 4% (0.3 mol H{sub 2}/mol sucrose), respectively. The intermediary products were acetic acid, butyric acid, methanol and ethanol in all of the anaerobic reactors. (author)

  8. Microbial granulation for lactic acid production.

    Science.gov (United States)

    Kim, Dong-Hoon; Lee, Mo-Kwon; Hwang, Yuhoon; Im, Wan-Taek; Yun, Yeo-Myeong; Park, Chul; Kim, Mi-Sun

    2016-01-01

    This work investigated the formation of microbial granules to boost the productivity of lactic acid (LA). The flocculated form of LA-producing microbial consortium, dominated by Lactobacillus sp. (91.5% of total sequence), was initially obtained in a continuous stirred-tank reactor (CSTR), which was fed with 2% glucose and operated at a hydraulic retention time (HRT) of 12 h and pH 5.0 ± 0.1 under a thermophilic condition (50°C). The mixed liquor in the CSTR was then transferred to an up-flow anaerobic sludge blanket reactor (UASB). The fermentation performance and granulation process were monitored with a gradual decrease of HRT from 8.0 to 0.17 h, corresponding to an increase in the substrate loading from 60 to 2,880 g glucose L(-1) d(-1) . As the operation continued, the accumulation of biomass in the UASB was clearly observed, which changed from flocculent to granular form with decrease in HRT. Up to the HRT decrease to 0.5 h, the LA concentration was maintained at 19-20 g L(-1) with over 90% of substrate removal efficiency. However, further decrease of HRT resulted in a decrease of LA concentration with increase in residual glucose. Nevertheless, the volumetric LA productivity continuously increased, reaching 67 g L-fermenter (-1) h(-1) at HRT 0.17 h. The size of LA-producing granules and hydrophobicity gradually increased with decrease in HRT, reaching 6.0 mm and 60%, respectively. These biogranules were also found to have high settling velocities and low porosities, ranging 2.69-4.73 cm s(-1) and 0.39-0.92, respectively. © 2015 Wiley Periodicals, Inc.

  9. Trends in microbial control techniques for poultry products.

    Science.gov (United States)

    Silva, Filomena; Domingues, Fernanda C; Nerín, Cristina

    2018-03-04

    Fresh poultry meat and poultry products are highly perishable foods and high potential sources of human infection due to the presence of several foodborne pathogens. Focusing on the microbial control of poultry products, the food industry generally implements numerous preventive measures based on the Hazard Analysis and Critical Control Points (HACCP) food safety management system certification together with technological steps, such as refrigeration coupled to modified atmosphere packaging that are able to control identified potential microbial hazards during food processing. However, in recent years, to meet the demand of consumers for minimally processed, high-quality, and additive-free foods, technologies are emerging associated with nonthermal microbial inactivation, such as high hydrostatic pressure, irradiation, and natural alternatives, such as biopreservation or the incorporation of natural preservatives in packaging materials. These technologies are discussed throughout this article, emphasizing their pros and cons regarding the control of poultry microbiota and their effects on poultry sensory properties. The discussion for each of the preservation techniques mentioned will be provided with as much detail as the data and studies provided in the literature for poultry meat and products allow. These new approaches, on their own, have proved to be effective against a wide range of microorganisms in poultry meat. However, since some of these emergent technologies still do not have full consumer's acceptability and, taking into consideration the hurdle technology concept for poultry processing, it is suggested that they will be used as combined treatments or, more frequently, in combination with modified atmosphere packaging.

  10. Production of Microbial Protease from Selected Soil Fungal Isolates ...

    African Journals Online (AJOL)

    Production of Microbial Protease from Selected Soil Fungal Isolates. ... Nigerian Journal of Biotechnology ... and 500C. The optimal pH on the enzyme production was observed to be between pH 3.5 and 5.5 for the organisms. Keywords: Soil microorganism, fungal isolate, incubation period, microbial enzyme. Nig J. Biotech.

  11. Combining microbial cultures for efficient production of electricity from butyrate in a microbial electrochemical cell

    Science.gov (United States)

    Miceli, Joseph F.; Garcia-Peña, Ines; Parameswaran, Prathap; Torres, César I.; Krajmalnik-Brown, Rosa

    2014-01-01

    Butyrate is an important product of anaerobic fermentation; however, it is not directly used by characterized strains of the highly efficient anode respiring bacteria (ARB) Geobacter sulfurreducens in microbial electrochemical cells. By combining a butyrate-oxidizing community with a Geobacter rich culture, we generated a microbial community which outperformed many naturally derived communities found in the literature for current production from butyrate and rivaled the highest performing natural cultures in terms of current density (~11 A/m2) and Coulombic efficiency (~70%). Microbial community analyses support the shift in the microbial community from one lacking efficient ARB in the marine hydrothermal vent community to a community consisting of ~80% Geobacter in the anode biofilm. This demonstrates the successful production and adaptation of a novel microbial culture for generating electrical current from butyrate with high current density and high Coulombic efficiency, by combining two mixed micro bial cultures containing complementing biochemical pathways. PMID:25048958

  12. Microbial Insights into Shifting Methane Production Potential in Thawing Permafrost

    Science.gov (United States)

    Crossen, K.; Wilson, R.; Raab, N.; Neumann, R.; Chanton, J.; Saleska, S. R.; Rich, V. I.

    2017-12-01

    Permafrost, which stores 50% of global soil carbon, is thawing rapidly due to climate change, and resident microbes are contributing to changing carbon gas emissions. Predictions of the fate of carbon in these regions is poorly constrained; however, improved, careful mapping of microbial community members influencing CO2 and CH4 emissions will help clarify the system response to continued change. In order to more fully understand connections between the microbial communities, major geochemical transformations, and CO2 and CH4 emissions, peat cores were collected from the active layers of three permafrost habitats spanning a thaw gradient (collapsed palsa, bog, and fen) at Stordalen Mire, Abisko, Sweden. Anaerobic incubations of shallow and deep subsamples from these sites were performed, with time-course characterization of the changes in microbial communities, peat geochemistry, and carbon gas production. The latter were profiled with 16S rRNA amplicon sequencing, and targeted metagenomes. The communities within each habitat and depth were statistically distinct, and changed significantly over the course of the incubations. Acidobacteria was consistently the dominant bacterial phylum in all three habitat types. With increased thaw, the relative abundance of Actinobacteria tended to decrease, while Chloroflexi and Bacteroidetes increased with thaw. The relative abundance of methanogens increased with thaw and with depth within each habitat. Over time in the incubations, the richness of the communities tended to decrease. Homoacetogenesis (CO2 + H2 -> CH3COOH) has been documented in other peatlands, and homoacetogens can influence CH4 production by interacting with methanogens, competing with hydrogenotrophs while providing substrate for acetoclasts. Modelling of microbial reaction networks suggests potential for highest homoacetogenesis rates in the collapsed palsa, which also contains the highest relative abundances of lineages taxonomically affiliated with known

  13. A comparative evaluation of different types of microbial electrolysis desalination cells for malic acid production.

    Science.gov (United States)

    Liu, Guangli; Zhou, Ying; Luo, Haiping; Cheng, Xing; Zhang, Renduo; Teng, Wenkai

    2015-12-01

    The aim of this study was to investigate different microbial electrolysis desalination cells for malic acid production. The systems included microbial electrolysis desalination and chemical-production cell (MEDCC), microbial electrolysis desalination cell (MEDC) with bipolar membrane and anion exchange membrane (BP-A MEDC), MEDC with bipolar membrane and cation exchange membrane (BP-C MEDC), and modified microbial desalination cell (M-MDC). The microbial electrolysis desalination cells performed differently in terms of malic acid production and energy consumption. The MEDCC performed best with the highest malic acid production rate (18.4 ± 0.6 mmol/Lh) and the lowest energy consumption (0.35 ± 0.14 kWh/kg). The best performance of MEDCC was attributable to the neutral pH condition in the anode chamber, the lowest internal resistance, and the highest Geobacter percentage of the anode biofilm population among all the reactors. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Microbial production of scleroglucan and downstream processing

    Directory of Open Access Journals (Sweden)

    Natalia Alejandra Castillo

    2015-10-01

    Full Text Available Synthetic petroleum-based polymers and natural plant polymers have the disadvantage of restricted sources, in addition to the non-biodegradability of the former ones. In contrast, eco-sustainable microbial polysaccharides, of low-cost and standardized production, represent an alternative to address this situation. With a strong global market, they attracted worldwide attention because of their novel and unique physico-chemical properties as well as varied industrial applications, and many of them are promptly becoming economically competitive. Scleroglucan, a beta-1,3-beta-1,6-glucan secreted by Sclerotium fungi, exhibits high potential for commercialization and may show different branching frequency, side-chain length and/or molecular weight depending on the producing strain or culture conditions. Water-solubility, viscosifying ability and wide stability over temperature, pH and salinity make scleroglucan useful for different biotechnological (enhanced oil recovery, food additives, drug delivery, cosmetic and pharmaceutical products, biocompatible materials, etc., and biomedical (immunoceutical, antitumor, etc. applications. It can be copiously produced at bioreactor scale under standardized conditions, where a high EPS concentration normally governs the process optimization. Operative and nutritional conditions, as well as the incidence of scleroglucan downstream processing will be discussed in this chapter. The relevance of using standardized inocula from selected strains and experiences concerning the intricate scleroglucan scaling-up will be also herein outlined.

  15. Microbial production of building block chemicals and polymers.

    Science.gov (United States)

    Lee, Jeong Wook; Kim, Hyun Uk; Choi, Sol; Yi, Jongho; Lee, Sang Yup

    2011-12-01

    Owing to our increasing concerns on the environment, climate change, and limited natural resources, there has recently been considerable effort exerted to produce chemicals and materials from renewable biomass. Polymers we use everyday can also be produced either by direct fermentation or by polymerization of monomers that are produced by fermentation. Recent advances in metabolic engineering combined with systems biology and synthetic biology are allowing us to more systematically develop superior strains and bioprocesses for the efficient production of polymers and monomers. Here, we review recent trends in microbial production of building block chemicals that can be subsequently used for the synthesis of polymers. Also, recent successful cases of direct one-step production of polymers are reviewed. General strategies for the production of natural and unnatural platform chemicals are described together with representative examples. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. Integrated hydrogen production process from cellulose by combining dark fermentation, microbial fuel cells, and a microbial electrolysis cell

    KAUST Repository

    Wang, Aijie; Sun, Dan; Cao, Guangli; Wang, Haoyu; Ren, Nanqi; Wu, Wei-Min; Logan, Bruce E.

    2011-01-01

    Hydrogen gas production from cellulose was investigated using an integrated hydrogen production process consisting of a dark fermentation reactor and microbial fuel cells (MFCs) as power sources for a microbial electrolysis cell (MEC). Two MFCs

  17. A Microbial Assessment Scheme to measure microbial performance of Food Safety Management Systems.

    Science.gov (United States)

    Jacxsens, L; Kussaga, J; Luning, P A; Van der Spiegel, M; Devlieghere, F; Uyttendaele, M

    2009-08-31

    A Food Safety Management System (FSMS) implemented in a food processing industry is based on Good Hygienic Practices (GHP), Hazard Analysis Critical Control Point (HACCP) principles and should address both food safety control and assurance activities in order to guarantee food safety. One of the most emerging challenges is to assess the performance of a present FSMS. The objective of this work is to explain the development of a Microbial Assessment Scheme (MAS) as a tool for a systematic analysis of microbial counts in order to assess the current microbial performance of an implemented FSMS. It is assumed that low numbers of microorganisms and small variations in microbial counts indicate an effective FSMS. The MAS is a procedure that defines the identification of critical sampling locations, the selection of microbiological parameters, the assessment of sampling frequency, the selection of sampling method and method of analysis, and finally data processing and interpretation. Based on the MAS assessment, microbial safety level profiles can be derived, indicating which microorganisms and to what extent they contribute to food safety for a specific food processing company. The MAS concept is illustrated with a case study in the pork processing industry, where ready-to-eat meat products are produced (cured, cooked ham and cured, dried bacon).

  18. Metabolic engineering for the microbial production of isoprenoids: Carotenoids and isoprenoid-based biofuels

    Directory of Open Access Journals (Sweden)

    Fu-Xing Niu

    2017-09-01

    Full Text Available Isoprenoids are the most abundant and highly diverse group of natural products. Many isoprenoids have been used for pharmaceuticals, nutraceuticals, flavors, cosmetics, food additives and biofuels. Carotenoids and isoprenoid-based biofuels are two classes of important isoprenoids. These isoprenoids have been produced microbially through metabolic engineering and synthetic biology efforts. Herein, we briefly review the engineered biosynthetic pathways in well-characterized microbial systems for the production of carotenoids and several isoprenoid-based biofuels.

  19. Microbial adhesion in flow displacement systems

    NARCIS (Netherlands)

    Busscher, HJ; van der Mei, HC

    Flow displacement systems are superior to many other (static) systems for studying microbial adhesion to surfaces because mass transport and prevailing shear conditions can be adequately controlled and notoriously ill-defined slight rinsing steps to remove so-called "loosely adhering organisms" can

  20. Microbial stress tolerance for biofuels. Systems biology

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Zonglin Lewis (ed.) [National Center for Agricultural Utilization Research, USDA-ARS, Peoria, IL (United States)

    2012-07-01

    The development of sustainable and renewable biofuels is attracting growing interest. It is vital to develop robust microbial strains for biocatalysts that are able to function under multiple stress conditions. This Microbiology Monograph provides an overview of methods for studying microbial stress tolerance for biofuels applications using a systems biology approach. Topics covered range from mechanisms to methodology for yeast and bacteria, including the genomics of yeast tolerance and detoxification; genetics and regulation of glycogen and trehalose metabolism; programmed cell death; high gravity fermentations; ethanol tolerance; improving biomass sugar utilization by engineered Saccharomyces; the genomics on tolerance of Zymomonas mobilis; microbial solvent tolerance; control of stress tolerance in bacterial host organisms; metabolomics for ethanologenic yeast; automated proteomics work cell systems for strain improvement; and unification of gene expression data for comparable analyses under stress conditions. (orig.)

  1. Microbial production of a biofuel (acetone-butanol-ethanol) in a continuous bioreactor: impact of bleed and simultaneous product removal

    Science.gov (United States)

    Acetone butanol ethanol (ABE) was produced in an integrated continuous fermentation and product recovery system using a microbial strain Clostridium beijerinckii BA101 for ABE production and fermentation gases (CO2 and H2) for product removal by gas stripping. This represents a continuation of our ...

  2. Microbial nitrogen cycling response to forest-based bioenergy production.

    Science.gov (United States)

    Minick, Kevan J; Strahm, Brian D; Fox, Thomas R; Sucre, Eric B; Leggett, Zakiya H

    2015-12-01

    Concern over rising atmospheric CO2 and other greenhouse gases due to fossil fuel combustion has intensified research into carbon-neutral energy production. Approximately 15.8 million ha of pine plantations exist across the southeastern United States, representing a vast land area advantageous for bioenergy production without significant landuse change or diversion of agricultural resources from food production. Furthermore, intercropping of pine with bioenergy grasses could provide annually harvestable, lignocellulosic biomass feedstocks along with production of traditional wood products. Viability of such a system hinges in part on soil nitrogen (N) availability and effects of N competition between pines and grasses on ecosystem productivity. We investigated effects of intercropping loblolly pine (Pinus taeda) with switchgrass (Panicum virgatum) on microbial N cycling processes in the Lower Coastal Plain of North Carolina, USA. Soil samples were collected from bedded rows of pine and interbed space of two treatments, composed of either volunteer native woody and herbaceous vegetation (pine-native) or pure switchgrass (pine-switchgrass) in interbeds. An in vitro 15N pool-dilution technique was employed to quantify gross N transformations at two soil depths (0-5 and 5-15 cm) on four dates in 2012-2013. At the 0-5 cm depth in beds of the pine-switchgrass treatment, gross N mineralization was two to three times higher in November and February compared to the pine-native treatment, resulting in increased NH4(+) availability. Gross and net nitrification were also significantly higher in February in the same pine beds. In interbeds of the pine-switchgrass treatment, gross N mineralization was lower from April to November, but higher in February, potentially reflecting positive effects of switchgrass root-derived C inputs during dormancy on microbial activity. These findings indicate soil N cycling and availability has increased in pine beds of the pine

  3. Alignment of microbial fitness with engineered product formation: obligatory coupling between acetate production and photoautotrophic growth.

    Science.gov (United States)

    Du, Wei; Jongbloets, Joeri A; van Boxtel, Coco; Pineda Hernández, Hugo; Lips, David; Oliver, Brett G; Hellingwerf, Klaas J; Branco Dos Santos, Filipe

    2018-01-01

    Microbial bioengineering has the potential to become a key contributor to the future development of human society by providing sustainable, novel, and cost-effective production pipelines. However, the sustained productivity of genetically engineered strains is often a challenge, as spontaneous non-producing mutants tend to grow faster and take over the population. Novel strategies to prevent this issue of strain instability are urgently needed. In this study, we propose a novel strategy applicable to all microbial production systems for which a genome-scale metabolic model is available that aligns the production of native metabolites to the formation of biomass. Based on well-established constraint-based analysis techniques such as OptKnock and FVA, we developed an in silico pipeline-FRUITS-that specifically 'Finds Reactions Usable in Tapping Side-products'. It analyses a metabolic network to identify compounds produced in anabolism that are suitable to be coupled to growth by deletion of their re-utilization pathway(s), and computes their respective biomass and product formation rates. When applied to Synechocystis sp. PCC6803, a model cyanobacterium explored for sustainable bioproduction, a total of nine target metabolites were identified. We tested our approach for one of these compounds, acetate, which is used in a wide range of industrial applications. The model-guided engineered strain shows an obligatory coupling between acetate production and photoautotrophic growth as predicted. Furthermore, the stability of acetate productivity in this strain was confirmed by performing prolonged turbidostat cultivations. This work demonstrates a novel approach to stabilize the production of target compounds in cyanobacteria that culminated in the first report of a photoautotrophic growth-coupled cell factory. The method developed is generic and can easily be extended to any other modeled microbial production system.

  4. Microbial ecology of hot desert edaphic systems.

    Science.gov (United States)

    Makhalanyane, Thulani P; Valverde, Angel; Gunnigle, Eoin; Frossard, Aline; Ramond, Jean-Baptiste; Cowan, Don A

    2015-03-01

    A significant proportion of the Earth's surface is desert or in the process of desertification. The extreme environmental conditions that characterize these areas result in a surface that is essentially barren, with a limited range of higher plants and animals. Microbial communities are probably the dominant drivers of these systems, mediating key ecosystem processes. In this review, we examine the microbial communities of hot desert terrestrial biotopes (including soils, cryptic and refuge niches and plant-root-associated microbes) and the processes that govern their assembly. We also assess the possible effects of global climate change on hot desert microbial communities and the resulting feedback mechanisms. We conclude by discussing current gaps in our understanding of the microbiology of hot deserts and suggest fruitful avenues for future research. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  5. Genome-scale biological models for industrial microbial systems.

    Science.gov (United States)

    Xu, Nan; Ye, Chao; Liu, Liming

    2018-04-01

    The primary aims and challenges associated with microbial fermentation include achieving faster cell growth, higher productivity, and more robust production processes. Genome-scale biological models, predicting the formation of an interaction among genetic materials, enzymes, and metabolites, constitute a systematic and comprehensive platform to analyze and optimize the microbial growth and production of biological products. Genome-scale biological models can help optimize microbial growth-associated traits by simulating biomass formation, predicting growth rates, and identifying the requirements for cell growth. With regard to microbial product biosynthesis, genome-scale biological models can be used to design product biosynthetic pathways, accelerate production efficiency, and reduce metabolic side effects, leading to improved production performance. The present review discusses the development of microbial genome-scale biological models since their emergence and emphasizes their pertinent application in improving industrial microbial fermentation of biological products.

  6. Review on production, characterization and applications of microbial levan.

    Science.gov (United States)

    Srikanth, Rapala; Reddy, Chinta H S S Sundhar; Siddartha, Gudimalla; Ramaiah, M Janaki; Uppuluri, Kiran Babu

    2015-04-20

    Levan is a homopolymer of fructose naturally obtained from both plants and microorganisms. Microbial levans are more advantageous, economical and industrially feasible with numerous applications. Bacterial levans are much larger than those produced by plants with multiple branches and molecular weights ranging from 2 to 100 million Da. However levans from plants generally have molecular weights ranging from about 2000 to 33,000 Da. Microbial levans have wide range of applications in food, medicine, pharmaceutical, cosmetic and commercial industrial sectors. With excellent polymeric medicinal properties and ease of production, microbial levan appear as a valuable and versatile biopolymer of the future. The present article summarizes and discusses the most essential properties of bioactive microbial levan and recent developments in its production, characterization and the emerging applications in health and industry. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Microbial control of hydrogen sulfide production

    Energy Technology Data Exchange (ETDEWEB)

    Montgomery, A.D.; Bhupathiraju, V.K.; Wofford, N.; McInerney, M.J. [Univ. of Oklahoma, Tulsa, OK (United States)] [and others

    1995-12-31

    A sulfide-resistant strain of Thiobacillus denitrificans, strain F, prevented the accumulation of sulfide by Desulfovibrio desulfuricans when both organisms were grown in liquid medium. The wild-type strain of T. denitrificans did not prevent the accumulation of sulfide produced by D. desulfuricans. Strain F also prevented the accumulation of sulfide by a mixed population of sulfate-reducing bacteria enriched from an oil field brine. Fermentation balances showed that strain F stoichiometrically oxidized the sulfide produced by D. desulfuricans and the oil field brine enrichment to sulfate. The ability of a strain F to control sulfide production in an experimental system of cores and formation water from the Redfield, Iowa, natural gas storage facility was also investigated. A stable, sulfide-producing biofilm was established in two separate core systems, one of which was inoculated with strain F while the other core system (control) was treated in an identical manner, but was not inoculated with strain F. When formation water with 10 mM acetate and 5 mM nitrate was injected into both core systems, the effluent sulfide concentrations in the control core system ranged from 200 to 460 {mu}M. In the test core system inoculated with strain F, the effluent sulfide concentrations were lower, ranging from 70 to 110 {mu}M. In order to determine whether strain F could control sulfide production under optimal conditions for sulfate-reducing bacteria, the electron donor was changed to lactate and inorganic nutrients (nitrogen and phosphate sources) were added to the formation water. When nutrient-supplemented formation water with 3.1 mM lactate and 10 mM nitrate was used, the effluent sulfide concentrations of the control core system initially increased to about 3,800 {mu}M, and then decreased to about 1,100 {mu}M after 5 weeks. However, in the test core system inoculated with strain F, the effluent sulfide concentrations were much lower, 160 to 330 {mu}M.

  8. Optimized microbial cells for production of melatonin and other compounds

    DEFF Research Database (Denmark)

    2017-01-01

    Described herein are recombinant microbial host cells comprising biosynthetic pathways and their use in producing oxidation products and downstream products, e.g., melatonin and related compounds, as well as enzyme variants, nucleic acids, vectors and methods useful for preparing and using...

  9. Microbial production of bulk chemicals: development of anaerobic processes

    NARCIS (Netherlands)

    Weusthuis, R.A.; Lamot, I.; Oost, van der J.; Sanders, J.P.M.

    2011-01-01

    nnovative fermentation processes are necessary for the cost-effective production of bulk chemicals from renewable resources. Current microbial processes are either anaerobic processes, with high yield and productivity, or less-efficient aerobic processes. Oxygen utilization plays an important role

  10. Microbial Reverse Electrodialysis Cells for Synergistically Enhanced Power Production

    KAUST Repository

    Kim, Younggy

    2011-07-01

    A new type of bioelectrochemical system for producing electrical power, called a microbial reverse-electrodialysis cell (MRC), was developed to increase voltages and power densities compared to those generated individually by microbial fuel cells (MFCs) or reverse electrodialysis (RED) systems. In RED systems, electrode overpotentials create significant energy losses due to thermodynamically unfavorable electrode reactions, and therefore a large number of stacked cells must be used to have significant energy recovery. This results in high capital costs for the large number of membranes, and increases energy losses from pumping water through a large number of cells. In an MRC, high overpotentials are avoided through oxidation of organic matter by exoelectrogenic bacteria on the anode and oxygen reduction on the cathode. An MRC containing only five pairs of RED cells, fed solutions typical of seawater (600 mM NaCl) and river water (12 mM NaCl) at 0.85 mL/min, produced up to 3.6 W/m2 (cathode surface area) and 1.2-1.3 V with acetate as a substrate. Pumping accounted for <2% of the produced power. A higher flow rate (1.55 mL/min) increased power densities up to 4.3 W/m2. COD removal was 98% with a Coulombic efficiency of 64%. Power production by the individual components was substantially lower with 0.7 W/m2 without salinity driven energy, and <0.015 W/m2 with reduced exoelectrogenic activity due to substrate depletion. These results show that the combination of an MFC and a RED stack synergistically increases performance relative to the individual systems, producing a new type of system that can be used to more efficiently capture salinity driven energy from seawater and river water. © 2011 American Chemical Society.

  11. Biochar and microbial signaling: production conditions determine effects on microbial communication

    Science.gov (United States)

    Masiello, Caroline A.; Chen, Ye; Gao, Xiaodong; Liu, Shirley; Cheng, Hsiao-Ying; Bennett, Matthew R.; Rudgers, Jennifer A.; Wagner, Daniel S.; Zygourakis, Kyriacos; Silberg, Jonathan J.

    2013-01-01

    Charcoal has a long soil residence time, which has resulted in its production and use as a carbon sequestration technique (biochar). A range of biological effects can be triggered by soil biochar that can positively and negatively influence carbon storage, such as changing the decomposition rate of organic matter and altering plant biomass production. Sorption of cellular signals has been hypothesized to underlie some of these effects, but it remains unknown whether the binding of biochemical signals occurs, and if so, on time scales relevant to microbial growth and communication. We examined biochar sorption of N-3-oxo-dodecanoyl-L-homoserine lactone, an acyl-homoserine lactone (AHL) intercellular signaling molecule used by many gram-negative soil microbes to regulate gene expression. We show that wood biochars disrupt communication within a growing multicellular system that is made up of sender cells that synthesize AHL and receiver cells that express green fluorescent protein in response to an AHL signal. However, biochar inhibition of AHL-mediated cell-cell communication varied, with the biochar prepared at 700°C (surface area of 301 m2/g) inhibiting cellular communication 10-fold more than an equivalent mass of biochar prepared at 300°C (surface area of 3 m2/g). These findings provide the first direct evidence that biochars elicit a range of effects on gene expression dependent on intercellular signaling, implicating the method of biochar preparation as a parameter that could be tuned to regulate microbial-dependent soil processes, like nitrogen fixation and pest attack of root crops. PMID:24066613

  12. Biochar and microbial signaling: production conditions determine effects on microbial communication.

    Science.gov (United States)

    Masiello, Caroline A; Chen, Ye; Gao, Xiaodong; Liu, Shirley; Cheng, Hsiao-Ying; Bennett, Matthew R; Rudgers, Jennifer A; Wagner, Daniel S; Zygourakis, Kyriacos; Silberg, Jonathan J

    2013-10-15

    Charcoal has a long soil residence time, which has resulted in its production and use as a carbon sequestration technique (biochar). A range of biological effects can be triggered by soil biochar that can positively and negatively influence carbon storage, such as changing the decomposition rate of organic matter and altering plant biomass production. Sorption of cellular signals has been hypothesized to underlie some of these effects, but it remains unknown whether the binding of biochemical signals occurs, and if so, on time scales relevant to microbial growth and communication. We examined biochar sorption of N-3-oxo-dodecanoyl-L-homoserine lactone, an acyl-homoserine lactone (AHL) intercellular signaling molecule used by many gram-negative soil microbes to regulate gene expression. We show that wood biochars disrupt communication within a growing multicellular system that is made up of sender cells that synthesize AHL and receiver cells that express green fluorescent protein in response to an AHL signal. However, biochar inhibition of AHL-mediated cell-cell communication varied, with the biochar prepared at 700 °C (surface area of 301 m(2)/g) inhibiting cellular communication 10-fold more than an equivalent mass of biochar prepared at 300 °C (surface area of 3 m(2)/g). These findings provide the first direct evidence that biochars elicit a range of effects on gene expression dependent on intercellular signaling, implicating the method of biochar preparation as a parameter that could be tuned to regulate microbial-dependent soil processes, like nitrogen fixation and pest attack of root crops.

  13. Modelling the bioconversion of cellulose into microbial products: rate limitations

    Energy Technology Data Exchange (ETDEWEB)

    Asenjo, J A

    1984-12-01

    The direct bioconversion of cellulose into microbial products carried out as a simultaneous saccharification and fermentation has a strong effect on the rates of cellulose degradation because cellobiose and glucose inhibition of the reaction are circumvented. A general mathematical model of the kinetics of this bioconversion has been developed. Its use in representing aerobic systems and in the analysis of the kinetic limitations has been investigated. Simulations have been carried out to find the rate limiting steps in slow fermentations and in rapid ones as determined by the specific rate of product formation. The requirements for solubilising and depolymerising enzyme activities (cellulase and cellobiase) in these systems has been determined. The activity that have been obtained for fungal cellulases are adequate for the kinetic requirements of the fastest fermentative strains. The results also show that for simultaneous bioconversions where strong cellobiose and glucose inhibition is overcome, no additional cellobiase is necessary to increase the rate of product formation. These results are useful for the selection of cellolytic micro-organisms and in the determination of enzymes to be cloned in recombinant strains. 17 references.

  14. Some non-thermal microbial inactivation methods in dairy products

    International Nuclear Information System (INIS)

    Yangilar, F.; Kabil, E.

    2013-01-01

    During the production of dairy products, some thermal processes such as pasteurization and sterilization are used commonly to inactive microorganisms. But as a result of thermal processes, loss of nutrient and aroma, non-enzymatic browning and organoleptic differentiation especially in dairy products are seen. Because of this, alternative methods are needed to provide microbial inactivation and as major problems are caused by high temperatures, non-thermal processes are focused on. For this purpose, some methods such as high pressure (HP), pulsed light (PL), ultraviolet radiation (UV), supercritical carbon dioxide (SC-CO2) or pulsed electric field (PEF) are used in food. These methods products are processed in ambient temperature and so not only mentioned losses are minimized but also freshness and naturality of products can be preserved. In this work, we will try to be given information about methods of non-thermal microbial inactivation of dairy products. (author) [tr

  15. Microbial Transformations of Actinides and Fission Products in Radioactive Waste

    Energy Technology Data Exchange (ETDEWEB)

    Francis, A. J. [Pohang Univ. Science and Technology, Pohang (Korea, Republic of)

    2011-07-01

    The environmental factors that can affect microbial growth and activity include moisture, temperature, ph, Eh, availability of organic and inorganic nutrients, and radiation. The microbial activity in a specific repository is influenced by the ambient environment of the repository, and the materials to be emplaced. For example, a repository in unsaturated igneous rock formations such as volcanic tuff rocks at Yucca Mountain is generally expected to be oxidizing; a repository in a hydrologically expected to be oxidizing; a repository in a hydrologically saturated zone, especially in sedimentary rocks, could be reducing. Sedimentary rocks contain a certain amount of organic matter, which may stimulate microbial activities and, thus maintain the repository and its surrounding areas at reducing conditions. Although the impacts of microbial activity on high-level nuclear waste and the long-term performance of the repository have not fully investigated, little microbial activity is expected in the near-field because of the radiation, lack of nutrients and the harsh conditions. However in the far-field microbial effects could be significant. Much of our understanding of the microbial effects on radionuclides stems from studies conducted with selected transuranic elements and fission products and limited studies with low-level radioactive wastes. Significant aerobic- and anaerobic-microbial activity is expected to occur in the waste because of the presence of electron donors and acceptors. The actinides initially may be present as soluble- or insoluble-forms but, after disposal, may be converted from one to the other by microorganisms. The direct enzymatic or indirect non-enzymatic actions of microbes could alter the speciation, solubility, and sorption properties of the actinides, thereby increasing or decreasing their concentrations in solution.

  16. Marine Microbial Systems Ecology: Microbial Networks in the Sea

    NARCIS (Netherlands)

    Muijzer, G.; Stal, L.J.; Cretoiu, M.S.

    2016-01-01

    Next-generation sequencing of DNA has revolutionized microbial ecology. Using this technology, it became for the first time possible to analyze hundreds of samples simultaneously and in great detail. 16S rRNA amplicon sequencing, metagenomics and metatranscriptomics became available to determine the

  17. Farm Deployable Microbial Bioreactor for Fuel Ethanol Production

    Energy Technology Data Exchange (ETDEWEB)

    Okeke, Benedict [Auburn Univ., Montgomery AL (United States)

    2016-03-30

    Research was conducted to develop a farm and field deployable microbial bioreactor for bioethanol production from biomass. Experiments were conducted to select the most efficient microorganisms for conversion of plant fiber to sugars for fermentation to ethanol. Mixtures of biomass and surface soil samples were collected from selected sites in Alabama black belt counties (Macon, Sumter, Choctaw, Dallas, Montgomery, Lowndes) and other areas within the state of Alabama. Experiments were conducted to determine the effects of culture parameters on key biomass saccharifying enzymes (cellulase, beta-glucosidase, xylanase and beta-xylosidase). A wide-scale sampling of locally-grown fruits in Central Alabama was embarked to isolate potential xylose fermenting microorganisms. Yeast isolates were evaluated for xylose fermentation. Selected microorganisms were characterized by DNA based methods. Factors affecting enzyme production and biomass saccharification were examined and optimized in the laboratory. Methods of biomass pretreatment were compared. Co-production of amylolytic enzymes with celluloytic-xylanolytic enzymes was evaluated; and co-saccharification of a combination of biomass, and starch-rich materials was examined. Simultaneous saccharification and fermentation with and without pre-saccharifcation was studied. Whole culture broth and filtered culture broth simultaneous saccahrifcation and fermentation were compared. A bioreactor system was designed and constructed to employ laboratory results for scale up of biomass saccharification.

  18. Microbial contamination of spices used in production of meat products

    Directory of Open Access Journals (Sweden)

    Marcela Klimešová

    2015-05-01

    Full Text Available There was investigated microbial quality of spices used in production of meat products (black pepper, allspice, coriander, juniper, cumin, cinnamon, badian, mustard, bay leaf, paprika, rosemary, garlic, ginger, thyme, cardamom. The spices were analysed on the presence of total count of mesophilic, thermoresistant and coliforming microorganisms, Staphylococcus aureus, methicilin resistant S. aureus (MRSA, Escherichia coli, Salmonella spp., Bacillus cereus, Bacillus licheniformis and moulds. For the detection of fungal contamination was used agar with glucose, yeast extract and oxytetracyklin and dichloran-glycerol agar. The cultivation was performed at 25 ±1°C for 5 - 7 days. The microscopic method was used for species identification. The aflatoxin presence was confirmed by ELISA test in all of tested spices and was performed in ppb (pars per billion = μg/kg. TCM ranged from 200 to 5600000 cfu/g, TRM from 20 to 90000 cfu/g and coliforming bacteria from 30 to 3200 cfu/g. B. cereus was present in juniper, mustard, bay leaf, thyme and cardamom (32%, while B. licheniformis was confirmed in 58% of cases (allspice, pepper, ground juniper, badian, bay leaf, paprika, garlic, thyme and cardamom. S. aureus was detected in whole coriander, cinnamon, badian and mustard but only in law number (30, 40, 20 and 10 cfu/g respectively. No strains S. aureus was identified as MRSA. The presence of Salmonella spp. and E. coli was not confirmed. The fungal contamination was found in 14 spices and the their count varied from 0 to 1550 cfu/g. There were confirmed the presence of Aspergillus flavus (allspice whole and ground, black pepper whole and ground, whole coriander, ground cumin, ground bay leaf, Aspergillus niger (allspice whole and ground, black pepper ground, ground juniper, cumin ground, bay leaf ground, ground rosemary, ground thyme, Penicillium glaucum (allspice whole and ground, whole juniper, whole cinnamon, Penicillium claviforme (whole black pepper

  19. Microbial production of lysine from sustainable feedstock

    DEFF Research Database (Denmark)

    Wang, Zhihao; Grishkova, Maria; Solem, Christian

    2014-01-01

    Lysine is produced in a fermentation process using Corynebacterium glutamicum. And even though production strains have been improved for decades, there is still room for further optimization.......Lysine is produced in a fermentation process using Corynebacterium glutamicum. And even though production strains have been improved for decades, there is still room for further optimization....

  20. Microbial degradation of chloroethenes in groundwater systems

    Science.gov (United States)

    Bradley, Paul M.

    The chloroethenes, tetrachloroethene (PCE) and trichloroethene (TCE) are among the most common contaminants detected in groundwater systems. As recently as 1980, the consensus was that chloroethene compounds were not significantly biodegradable in groundwater. Consequently, efforts to remediate chloroethene-contaminated groundwater were limited to largely unsuccessful pump-and-treat attempts. Subsequent investigation revealed that under reducing conditions, aquifer microorganisms can reductively dechlorinate PCE and TCE to the less chlorinated daughter products dichloroethene (DCE) and vinyl chloride (VC). Although recent laboratory studies conducted with halorespiring microorganisms suggest that complete reduction to ethene is possible, in the majority of groundwater systems reductive dechlorination apparently stops at DCE or VC. However, recent investigations conducted with aquifer and stream-bed sediments have demonstrated that microbial oxidation of these reduced daughter products can be significant under anaerobic redox conditions. The combination of reductive dechlorination of PCE and TCE under anaerobic conditions followed by anaerobic microbial oxidation of DCE and VC provides a possible microbial pathway for complete degradation of chloroethene contaminants in groundwater systems. Résumé Les chloroéthanes, tétrachloroéthane (PCE) et trichloroéthane (TCE) sont parmi les polluants les plus communs trouvés dans les aquifères. Depuis les années 1980, on considère que les chloroéthanes ne sont pas significativement biodégradables dans les aquifères. Par conséquent, les efforts pour dépolluer les nappes contaminées par des chloroéthanes se sont limités à des tentatives de pompage-traitement globalement sans succès. Des travaux ultérieurs ont montré que dans des conditions réductrices, des micro-organismes présents dans les aquifères peuvent, par réduction, dégrader les PCE et TCE en composés moins chlorés, comme le dichlor

  1. Production of microbial glycolipid biosurfactants and their antimicrobial activity

    Science.gov (United States)

    Microbial glycolipids produced by bacteria or yeast as secondary metabolites, such as sophorolipids (SLs), rhamnolipids (RLs) and mannosylerythritol lipids (MELs) are “green” biosurfactants desirable in a bioeconomy. High cost of production is a major hurdle toward widespread commercial use of bios...

  2. Studies on potential effects of fumaric acid on rumen microbial fermentation, methane production and microbial community.

    Science.gov (United States)

    Riede, Susanne; Boguhn, Jeannette; Breves, Gerhard

    2013-01-01

    The greenhouse gas methane (CH4) contributes substantially to global climate change. As a potential approach to decrease ruminal methanogenesis, the effects of different dosages of fumaric acid (FA) on ruminal microbial metabolism and on the microbial community (archaea, bacteria) were studied using a rumen simulation technique (RUSITEC). FA acts as alternative hydrogen acceptor diverting 2H from methanogenesis of archaea towards propionate formation of bacteria. Three identical trials were conducted with 12 fermentation vessels over a period of 14 days. In each trial, four fermentation vessels were assigned to one of the three treatment groups differing in FA dosage: low fumaric acid (LFA), high fumaric acid (HFA) and without FA (control). FA was continuously infused with the buffer. Grass silage and concentrate served as substrate. FA led to decreases in pH and to higher production rates of total short chain fatty acids (SCFA) mediated by increases in propionate for LFA of 1.69 mmol d(-1) and in propionate and acetate production for HFA of 4.49 and 1.10 mmol d(-1), respectively. Concentrations of NH3-N, microbial crude protein synthesis, their efficiency, degradation of crude nutrients and detergent fibre fraction were unchanged. Total gas and CH4 production were not affected by FA. Effects of FA on structure of microbial community by means of single strand conformation polymorphism (SSCP) analyses could not be detected. Given the observed increase in propionate production and the unaffected CH4 production it can be supposed that the availability of reduction equivalents like 2H was not limited by the addition of FA in this study. It has to be concluded from the present study that the application of FA is not an appropriate approach to decrease the ruminal CH4 production.

  3. Production of aromas and fragrances through microbial oxidation of monoterpenes

    Directory of Open Access Journals (Sweden)

    H. F. Rozenbaum

    2006-09-01

    Full Text Available Aromas and fragrances can be obtained through the microbial oxidation of monoterpenes. Many microorganisms can be used to carry out extremely specific conversions using substrates of low commercial value. However, for many species, these substrates are highly toxic, consequently inhibiting their metabolism. In this work, the conversion ability of Aspergillus niger IOC-3913 for terpenic compounds was examined. This species was preselected because of its high resistance to toxic monoterpenic substrates. Though it has been grown in media containing R-limonene (one of the cheapest monoterpenic hydrocarbons, which is widely available on the market, the species has not shown the ability to metabolize it, since biotransformation products were not detected in high resolution gas chromatography analyses. For this reason, other monoterpenes (alpha-pinene, beta-pinene and camphor were used as substrates. These compounds were shown to be metabolized by the selected strain, producing oxidized compounds. Four reaction systems were used: a biotransformation in a liquid medium with cells in growth b with pre-grown cultures c with cells immobilized in a synthetic polymer network and d in a solid medium to which the substrate was added via the gas phase. The main biotransformation products were found in all the reaction systems, although the adoption of previously cultivated cells seemed to favor biotransformation. Cell immobilization seemed to be a feasible strategy for alleviating the toxic effect of the substrate. Through mass spectrometry it was possible to identify verbenone and alpha-terpineol as the biotransformation products of alpha-pinene and beta-pinene, respectively. The structures of the other oxidation products are described.

  4. PHA Production in Aerobic Mixed Microbial Cultures

    NARCIS (Netherlands)

    Johnson, K.

    2010-01-01

    Polyhydroxyalkanoate (PHA) is a common intracellular energy and carbon storage material in bacteria, which is considered as a bioplastic due to its plastic like properties. PHAs are versatile materials which are biodegradable and made from renewable resources. Commercial production of PHAs is

  5. Microbial platform for production of aromatic compounds

    DEFF Research Database (Denmark)

    Skovbjerg, Christine Alexandra Egaa; Olsen, Kresten Jon Kromphardt; Larsen, Thomas Ostenfeld

    2017-01-01

    Polyketides form the basic building blocks of numerous natural products, which are in use in pharmaceuticals, food additives and other fine chemicals. Many of these polyketides possess very specific cyclic and aromatic conformations. The programmable platform we aim to create will be able...

  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 biotechnologies for potable water production

    DEFF Research Database (Denmark)

    Fowler, S. Jane; Smets, Barth F.

    2017-01-01

    Sustainable Development Goal 6 requires the provision of safe drinking water to the world. We propose that increased exploitation of biological processes is fundamental to achieving this goal due to their low economic and energetic costs. Biological processes exist for the removal of most common...... contaminants, and biofiltration processes can establish a biologically stable product that retains high quality in distribution networks, minimizing opportunities for pathogen invasion....

  8. Microbial production strategies and applications of lycopene and other terpenoids.

    Science.gov (United States)

    Ma, Tian; Deng, Zixin; Liu, Tiangang

    2016-01-01

    Terpenoids are a large class of compounds that have far-reaching applications and economic value, particularly those most commonly found in plants; however, the extraction and synthesis of these compounds is often expensive and technically challenging. Recent advances in microbial metabolic engineering comprise a breakthrough that may enable the efficient, cost-effective production of these limited natural resources. Via the engineering of safe, industrial microorganisms that encode product-specific enzymes, and even entire metabolic pathways of interest, microbial-derived semisynthetic terpenoids may soon replace plant-derived terpenoids as the primary source of these valuable compounds. Indeed, the recent metabolic engineering of an Escherichia coli strain that produces the precursor to lycopene, a commercially and medically important compound, with higher yields than those in tomato plants serves as a successful example. Here, we review the recent developments in the metabolic engineering of microbes for the production of certain terpenoid compounds, particularly lycopene, which has been increasingly used in pharmaceuticals, nutritional supplements, and cosmetics. Furthermore, we summarize the metabolic engineering strategies used to achieve successful microbial production of some similar compounds. Based on this overview, there is a reason to believe that metabolic engineering comprises an optimal approach for increasing the production of lycopene and other terpenoids.

  9. Renewable sustainable biocatalyzed electricity production in a photosynthetic algal microbial fuel cell (PAMFC)

    NARCIS (Netherlands)

    Strik, D.P.B.T.B.; Terlouw, H.; Hamelers, H.V.M.; Buisman, C.J.N.

    2008-01-01

    Electricity production via solar energy capturing by living higher plants and microalgae in combination with microbial fuel cells are attractive because these systems promise to generate useful energy in a renewable, sustainable, and efficient manner. This study describes the proof of principle of a

  10. Microbial production of glucose/fructose syrups

    Energy Technology Data Exchange (ETDEWEB)

    Matur, A.; Saglam, N.

    1982-04-01

    With the ever-increasing demand for sugar and the trend in rising price, rapid progress in research on new and/or alternative sweeteners has been inevitable during the past decade or so. Pure glucose, glucose/fructose, glucose/maltose syrups are often called isosyrups. Isosyrups have been recognized as a good alternative sources of sugar. These are used today in the manufacture of soft drinks, jams and jellies, confectionary, baking fermentation, dietetic and infant food, ice-cream, pharmaceutical processes, etc. Isosyrups are produced by hydrolysis of starch and cellulocis raw materials have been utilized for the production of isosyrups.

  11. Chemical Biology of Microbial Anticancer Natural Products

    DEFF Research Database (Denmark)

    Bladt, Tanja Thorskov; Gotfredsen, Charlotte Held

    than 100 years. New natural products (NPs) are continually discovered and with the increase in selective biological assays, previously described compounds often also display novel bioactivities, justifying their presence in novel screening efforts. Screening and discovery of compounds with activity...... towards chronic lymphocytic leukemia (CLL) cells is crucial since CLL is considered as an incurable disease. To discover novel agents that targets CLL cells is complicated. CLL cells rapidly undergo apoptosis in vitro when they are removed from their natural microenvironment, even though they are long...

  12. Versatile microbial surface-display for environmental remediation and biofuels production

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Cindy H.; Mulchandani, Ashok; Chen, wilfred

    2008-02-14

    Surface display is a powerful technique that utilizes natural microbial functional components to express proteins or peptides on the cell exterior. Since the reporting of the first surface-display system in the mid-1980s, a variety of new systems have been reported for yeast, Gram-positive and Gram-negative bacteria. Non-conventional display methods are emerging, eliminating the generation of genetically modified microorganisms. Cells with surface display are used as biocatalysts, biosorbents and biostimulants. Microbial cell-surface display has proven to be extremely important for numerous applications ranging from combinatorial library screening and protein engineering to bioremediation and biofuels production.

  13. Microbial Production of Food Grade Pigments

    Directory of Open Access Journals (Sweden)

    Laurent Dufossé

    2006-01-01

    Full Text Available The controversial topic of synthetic dyes in food has been discussed for many years. The scrutiny and negative assessment of synthetic food dyes by the modern consumer have raised a strong interest in natural colouring alternatives. Nature is rich in colours (minerals, plants, microalgae, etc., and pigment-producing microorganisms (fungi, yeasts, bacteria are quite common. Among the molecules produced by microorganisms are carotenoids, melanins, flavins, quinones, and more specifically monascins, violacein or indigo. The success of any pigment produced by fermentation depends upon its acceptability on the market, regulatory approval, and the size of the capital investment required to bring the product to market. A few years ago, some expressed doubts about the successful commercialization of fermentation-derived food grade pigments because of the high capital investment requirements for fermentation facilities and the extensive and lengthy toxicity studies required by regulatory agencies. Public perception of biotechnology-derived products also had to be taken into account. Nowadays some fermentative food grade pigments are on the market: Monascus pigments, astaxanthin from Xanthophyllomyces dendrorhous, Arpink Red from Penicillium oxalicum, riboflavin from Ashbya gossypii, b-carotene from Blakeslea trispora. The successful marketing of pigments derived from algae or extracted from plants, both as a food colour and a nutritional supplement, reflects the presence and importance of niche markets in which consumers are willing to pay a premium for »all natural ingredients«.

  14. 40 CFR 158.2160 - Microbial pesticides product performance data requirements.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Microbial pesticides product... AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Microbial Pesticides § 158.2160 Microbial pesticides product performance data requirements. Product performance data must be developed for...

  15. Submersible microbial fuel cell for electricity production from sewage sludge

    DEFF Research Database (Denmark)

    Zhang, Yifeng; Olias, Lola Gonzalez; Kongjan, Prawit

    2010-01-01

    A submersible microbial fuel cell (SMFC) was utilized to treatment of sewage sludge and simultaneous generate electricity. Stable power generation (145±5 mW/m2) was produced continuously from raw sewage sludge for 5.5 days. The corresponding total chemical oxygen demand (TCOD) removal efficiency...... of an effective system to treatment of sewage sludge and simultaneous recover energy....

  16. Microbial and nutritional aspects on the production of live feeds in a fish farming industry.

    Science.gov (United States)

    De Donno, A; Lugoli, F; Bagordo, F; Vilella, S; Campa, A; Grassi, T; Guido, M

    2010-03-01

    Aquaculture is an enterprise in constant development, in particular relating to its effect on the environment and also the quality of its products. It represents a valid alternative to traditional fishing, facing the increasing demand for fish products. To guarantee to the consumer a product of high nutritional, organoleptic and hygienic quality, it is fundamental to monitor every phase of the fish farming industry, isolating the potential risk points. For this reason there has been a rapid evolution of productive technique, particularly in the technology, artificial reproduction and feed sectors. The aim of this research has been the monitoring of the evolution of certain microbial and nutritional quality indexes (total microbial counts and lipid analysis on suspensions of Rotifers and Artemia, used as live feed) in the larval phase of the productive cycle of the farm raised fish, in an intensive system. The study has shown an increment in the total microbial counts in the fish farming industry within the production of Rotifers and Artemia, more evident in the suspensions of Rotifers. In addition the study has demonstrated that the maintenance phase, in the enrichment protocol, can reduce the EPA and DHA content. The results confirm the importance of microbial and nutritional control of the live feeds before they get supplied to fish larvae.

  17. Microbial production of poly-γ-glutamic acid.

    Science.gov (United States)

    Sirisansaneeyakul, Sarote; Cao, Mingfeng; Kongklom, Nuttawut; Chuensangjun, Chaniga; Shi, Zhongping; Chisti, Yusuf

    2017-09-05

    Poly-γ-glutamic acid (γ-PGA) is a natural, biodegradable and water-soluble biopolymer of glutamic acid. This review is focused on nonrecombinant microbial production of γ-PGA via fermentation processes. In view of its commercial importance, the emphasis is on L-glutamic acid independent producers (i.e. microorganisms that do not require feeding with the relatively expensive amino acid L-glutamic acid to produce γ-PGA), but glutamic acid dependent production is discussed for comparison. Strategies for improving production, reducing costs and using renewable feedstocks are discussed.

  18. Microbial network for waste activated sludge cascade utilization in an integrated system of microbial electrolysis and anaerobic fermentation

    DEFF Research Database (Denmark)

    Liu, Wenzong; He, Zhangwei; Yang, Chunxue

    2016-01-01

    in an integrated system of microbial electrolysis cell (MEC) and anaerobic digestion (AD) for waste activated sludge (WAS). Microbial communities in integrated system would build a thorough energetic and metabolic interaction network regarding fermentation communities and electrode respiring communities...... to Firmicutes (Acetoanaerobium, Acetobacterium, and Fusibacter) showed synergistic relationship with exoelectrogensin the degradation of complex organic matter or recycling of MEC products (H2). High protein and polysaccharide but low fatty acid content led to the dominance of Proteiniclasticum...... biofilm. The overall performance of WAS cascade utilization was substantially related to the microbial community structures, which in turn depended on the initial pretreatment to enhance WAS fermentation. It is worth noting that species in AD and MEC communities are able to build complex networks...

  19. Integrated hydrogen production process from cellulose by combining dark fermentation, microbial fuel cells, and a microbial electrolysis cell

    KAUST Repository

    Wang, Aijie

    2011-03-01

    Hydrogen gas production from cellulose was investigated using an integrated hydrogen production process consisting of a dark fermentation reactor and microbial fuel cells (MFCs) as power sources for a microbial electrolysis cell (MEC). Two MFCs (each 25mL) connected in series to an MEC (72mL) produced a maximum of 0.43V using fermentation effluent as a feed, achieving a hydrogen production rate from the MEC of 0.48m 3 H 2/m 3/d (based on the MEC volume), and a yield of 33.2mmol H 2/g COD removed in the MEC. The overall hydrogen production for the integrated system (fermentation, MFC and MEC) was increased by 41% compared with fermentation alone to 14.3mmol H 2/g cellulose, with a total hydrogen production rate of 0.24m 3 H 2/m 3/d and an overall energy recovery efficiency of 23% (based on cellulose removed) without the need for any external electrical energy input. © 2010 Elsevier Ltd.

  20. Integrated hydrogen production process from cellulose by combining dark fermentation, microbial fuel cells, and a microbial electrolysis cell.

    Science.gov (United States)

    Wang, Aijie; Sun, Dan; Cao, Guangli; Wang, Haoyu; Ren, Nanqi; Wu, Wei-Min; Logan, Bruce E

    2011-03-01

    Hydrogen gas production from cellulose was investigated using an integrated hydrogen production process consisting of a dark fermentation reactor and microbial fuel cells (MFCs) as power sources for a microbial electrolysis cell (MEC). Two MFCs (each 25 mL) connected in series to an MEC (72 mL) produced a maximum of 0.43 V using fermentation effluent as a feed, achieving a hydrogen production rate from the MEC of 0.48 m(3) H(2)/m(3)/d (based on the MEC volume), and a yield of 33.2 mmol H(2)/g COD removed in the MEC. The overall hydrogen production for the integrated system (fermentation, MFC and MEC) was increased by 41% compared with fermentation alone to 14.3 mmol H(2)/g cellulose, with a total hydrogen production rate of 0.24 m(3) H(2)/m(3)/d and an overall energy recovery efficiency of 23% (based on cellulose removed) without the need for any external electrical energy input. Copyright © 2010 Elsevier Ltd. All rights reserved.

  1. Engineering microbial electrocatalysis for chemical and fuel production.

    Science.gov (United States)

    Rosenbaum, Miriam A; Henrich, Alexander W

    2014-10-01

    In many biotechnological areas, metabolic engineering and synthetic biology have become core technologies for biocatalyst development. Microbial electrocatalysis for biochemical and fuel production is still in its infancy and reactions rates and the product spectrum are currently very low. Therefore, molecular engineering strategies will be crucial for the advancement and realization of many new bioproduction routes using electroactive microorganisms. The complex and unresolved biochemistry and physiology of extracellular electron transfer and the lack of molecular tools for these new non-model hosts for genetic engineering constitute the major challenges for this effort. This review is providing an insight into the current status, challenges and promising approaches of pathway engineering for microbial electrocatalysis. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Microbial Electrolysis Cells for High Yield Hydrogen Gas Production from Organic Matter

    KAUST Repository

    Logan, Bruce E.

    2008-12-01

    The use of electrochemically active bacteria to break down organic matter, combined with the addition of a small voltage (>0.2 V in practice) in specially designed microbial electrolysis cells (MECs), can result in a high yield of hydrogen gas. While microbial electrolysis was invented only a few years ago, rapid developments have led to hydrogen yields approaching 100%, energy yields based on electrical energy input many times greater than that possible by water electrolysis, and increased gas production rates. MECs used to make hydrogen gas are similar in design to microbial fuel cells (MFCs) that produce electricity, but there are important differences in architecture and analytical methods used to evaluate performance. We review here the materials, architectures, performance, and energy efficiencies of these MEC systems that show promise as a method for renewable and sustainable energy production, and wastewater treatment. © 2008 American Chemical Society.

  3. Microbial fuel cells and microbial electrolysis cells for the production of bioelectricity and biomaterials.

    Science.gov (United States)

    Zhou, Minghua; Yang, Jie; Wang, Hongyu; Jin, Tao; Xu, Dake; Gu, Tingyue

    2013-01-01

    Today's global energy crisis requires a multifaceted solution. Bioenergy is an important part of the solution. The microbial fuel cell (MFC) technology stands out as an attractive potential technology in bioenergy. MFCs can convert energy stored in organic matter directly into bioelectricity. MFCs can also be operated in the electrolysis mode as microbial electrolysis cells to produce bioproducts such as hydrogen and ethanol. Various wastewaters containing low-grade organic carbons that are otherwise unutilized can be used as feed streams for MFCs. Despite major advances in the past decade, further improvements in MFC power output and cost reduction are needed for MFCs to be practical. This paper analysed MFC operating principles using bioenergetics and bioelectrochemistry. Several major issues were explored to improve the MFC performance. An emphasis was placed on the use of catalytic materials for MFC electrodes. Recent advances in the production of various biomaterials using MFCs were also investigated.

  4. Perspective for Aquaponic Systems: “Omic” Technologies for Microbial Community Analysis

    Directory of Open Access Journals (Sweden)

    Perla Munguia-Fragozo

    2015-01-01

    Full Text Available Aquaponics is the combined production of aquaculture and hydroponics, connected by a water recirculation system. In this productive system, the microbial community is responsible for carrying out the nutrient dynamics between the components. The nutrimental transformations mainly consist in the transformation of chemical species from toxic compounds into available nutrients. In this particular field, the microbial research, the “Omic” technologies will allow a broader scope of studies about a current microbial profile inside aquaponics community, even in those species that currently are unculturable. This approach can also be useful to understand complex interactions of living components in the system. Until now, the analog studies were made to set up the microbial characterization on recirculation aquaculture systems (RAS. However, microbial community composition of aquaponics is still unknown. “Omic” technologies like metagenomic can help to reveal taxonomic diversity. The perspectives are also to begin the first attempts to sketch the functional diversity inside aquaponic systems and its ecological relationships. The knowledge of the emergent properties inside the microbial community, as well as the understanding of the biosynthesis pathways, can derive in future biotechnological applications. Thus, the aim of this review is to show potential applications of current “Omic” tools to characterize the microbial community in aquaponic systems.

  5. Perspective for Aquaponic Systems: “Omic” Technologies for Microbial Community Analysis

    Science.gov (United States)

    Munguia-Fragozo, Perla; Alatorre-Jacome, Oscar; Rico-Garcia, Enrique; Cruz-Hernandez, Andres; Ocampo-Velazquez, Rosalia V.; Garcia-Trejo, Juan F.; Guevara-Gonzalez, Ramon G.

    2015-01-01

    Aquaponics is the combined production of aquaculture and hydroponics, connected by a water recirculation system. In this productive system, the microbial community is responsible for carrying out the nutrient dynamics between the components. The nutrimental transformations mainly consist in the transformation of chemical species from toxic compounds into available nutrients. In this particular field, the microbial research, the “Omic” technologies will allow a broader scope of studies about a current microbial profile inside aquaponics community, even in those species that currently are unculturable. This approach can also be useful to understand complex interactions of living components in the system. Until now, the analog studies were made to set up the microbial characterization on recirculation aquaculture systems (RAS). However, microbial community composition of aquaponics is still unknown. “Omic” technologies like metagenomic can help to reveal taxonomic diversity. The perspectives are also to begin the first attempts to sketch the functional diversity inside aquaponic systems and its ecological relationships. The knowledge of the emergent properties inside the microbial community, as well as the understanding of the biosynthesis pathways, can derive in future biotechnological applications. Thus, the aim of this review is to show potential applications of current “Omic” tools to characterize the microbial community in aquaponic systems. PMID:26509157

  6. Microbial quality of some medicinal herbal products in Kashan, Iran

    Directory of Open Access Journals (Sweden)

    Mazroi Arani Navid

    2014-04-01

    Full Text Available Introduction: The use of medicinal plants has risen worldwide. In Iran, herbal waters and rose waters are of traditional medicinal products and as a result, they are widespreadly consumed. Therefore, diagnosis of microbial quality of these products is important. The aim of this study was to evaluate microbial quality of herbal extracts distributed in Kashan, Iran. Methods: In this descriptive study, 256 samples of herbal waters and 191 samples of rose waters (total samples of 447 distributed in Kashan during 2012 to 2013 were purchased and transferred to laboratory. Then microbial tests such as total aerobic bacterial count, mold and yeast count, total coliforms, and detection of Enterococcus, Pseudomonas and sulphite-reducing Clostridia were evaluated based on national standard of Iran. Results: Contamination with Pseudomonas and Enterococcus was observed in the herbal water samples. 196 cases (43.84% of the total samples, 113 cases (44.15% of the herbal waters and 83 cases (43.45% of the rose waters were usable based on the national standard of Iran. Neither herbal waters nor rosewater samples were contaminated by E.Coli and Sulphite-reducing clostridia. Additionally, none of the rosewater samples was contaminated by Coliforms and Pseudomonas. Conclusion: Based on the findings and due to the fact that these products are contaminated with aerobic mesophilic bacteria, mold and yeast, to minimize the risks we recommend to apply pasteurized temperature, high-quality packaging material and hygiene observance in processing time of herbal waters and rose waters.

  7. Microbial Metabolite Production for Accelerated Metal and Radionuclide Bioremediation (Microbial Metabolite Production Report)

    International Nuclear Information System (INIS)

    TURICK, CHARLES

    2004-01-01

    Biogeochemical activity is an ongoing and dynamic process due to bacterial activity in the subsurface. Bacteria contribute significantly to biotransformation of metals and radionuclides. As basic science reveals more information about specific mechanisms of bacterial-metal reduction, an even greater contribution of bacteria to biogeochemical activities is realized. An understanding and application of the mechanisms of metal and radionuclide reduction offers tremendous potential for development into bioremedial processes and technologies. Most bacteria are capable of biogeochemical transformation as a result of meeting nutrient requirements. These assimilatory mechanisms for metals transformation include production of small molecules that serve as electron shuttles for metal reduction. This contribution to biogeochemistry is small however due to only trace requirements for minerals by bacteria. Dissimilatory metal reducing bacteria (DMRB) reduce oxidized metals and insoluble mineral oxides as a means for biological energy production during growth. These types of bacteria offer considerable potential for bioremediation of environments contaminated with toxic metals and radionuclides because of the relatively large amount of metal biotransformation they require for growth. One of the mechanisms employed by some DMRB for electron transfer to insoluble metal oxides is melanin production. The electrochemical properties of melanin provide this polymeric, humic-type compound with electron shuttling properties. Melanin, specifically, pyomelanin, increases the rate and degree of metal reduction in DMRB as a function of pyomelanin concentration. Due to its electron shuttling behavior, only low femtogram quantities per cell are required to significantly increase metal reduction capacity of DMRB. Melanin production is not limited to DMRB. In fact melanin is one of the most common pigments produced by biological systems. Numerous soil microorganisms produce melanin, contributing

  8. Microbial xylanases: engineering, production and industrial applications.

    Science.gov (United States)

    Juturu, Veeresh; Wu, Jin Chuan

    2012-01-01

    Enzymatic depolymerization of hemicellulose to monomer sugars needs the synergistic action of multiple enzymes, among them endo-xylanases (EC 3.2.1.8) and β-xylosidases (EC 3.2.1.37) (collectively xylanases) play a vital role in depolymerizing xylan, the major component of hemicellulose. Recent developments in recombinant protein engineering have paved the way for engineering and expressing xylanases in both heterologous and homologous hosts. Functional expression of endo-xylanases has been successful in many hosts including bacteria, yeasts, fungi and plants with yeasts being the most promising expression systems. Functional expression of β-xylosidases is more challenging possibly due to their more complicated structures. The structures of endo-xylanases of glycoside hydrolase families 10 and 11 have been well elucidated. Family F/10 endo-xylanases are composed of a cellulose-binding domain and a catalytic domain connected by a linker peptide with a (β/α)8 fold TIM barrel. Family G/11 endo-xylanases have a β-jelly roll structure and are thought to be able to pass through the pores of hemicellulose network owing to their smaller molecular sizes. The structure of a β-D-xylosidase belonging to family 39 glycoside hydrolase has been elucidated as a tetramer with each monomer being composed of three distinct regions: a catalytic domain of the canonical (β/α)8--TIM barrel fold, a β-sandwich domain and a small α-helical domain with the enzyme active site that binds to D-xylooligomers being present on the upper side of the barrel. Glycosylation is generally considered as one of the most important post-translational modifications of xylanases, but a few examples showed functional expression of eukaryotic xylanases in bacteria. The optimal ratio of these synergistic enzymes is very important in improving hydrolysis efficiency and reducing enzyme dosage but has hardly been addressed in literature. Xylanases have been used in traditional fields such as food, feed

  9. A new protocol for evaluating the efficacy of some dispensing systems of a packaging in the microbial protection of water-based preservative-free cosmetic products.

    Science.gov (United States)

    Devlieghere, F; De Loy-Hendrickx, A; Rademaker, M; Pipelers, P; Crozier, A; De Baets, B; Joly, L; Keromen, S

    2015-12-01

    A new protocol is described for assessing the efficacy of the dispenser of some packaging systems (PSs) of preservative-free cosmetic products in protecting both their contained formula and their delivered doses. Practically, aiming at mimicking contacts with a non-sterile skin or fingers, the dispensing system is put into contact with a pre-contaminated fabric by a standardized colonization of P. aeruginosa. When applied to three different types of packaging, results show clear differences in both criteria between these conditioning articles, that is variable efficacies in protecting the contained product and the delivered doses, knowing that the first aspect is of paramount importance. The proposed protocol is proved being able to discriminate between different PSs and provides information on strong and weak features of certain types dispensing technologies prone to efficiently decrease either the dose contamination or to prevent contamination in reaching the contained product. Therefore, the proposed protocol can contribute to an objective selection of a PS for protecting a cosmetic care product with a low content of preservative or preservative free. © 2015 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  10. Microbial hydrogen production from sewage sludge bioaugmented with a constructed microbial consortium

    Energy Technology Data Exchange (ETDEWEB)

    Kotay, Shireen Meher; Das, Debabrata [Department of Biotechnology, Indian Institute of Technology, Kharagpur 721302 (India)

    2010-10-15

    A constructed microbial consortium was formulated from three facultative H{sub 2}-producing anaerobic bacteria, Enterobacter cloacae IIT-BT 08, Citrobacter freundii IIT-BT L139 and Bacillus coagulans IIT-BT S1. This consortium was tested as the seed culture for H{sub 2} production. In the initial studies with defined medium (MYG), E. cloacae produced more H{sub 2} than the other two strains and it also was found to be the dominant member when consortium was used. On the other hand, B. coagulans as a pure culture gave better H{sub 2} yield (37.16 ml H{sub 2}/g COD{sub consumed}) than the other two strains using sewage sludge as substrate. The pretreatment of sludge included sterilization (15% v/v), dilution and supplementation with 0.5% w/v glucose, which was found to be essential to screen out the H{sub 2} consuming bacteria and ameliorate the H{sub 2} production. Considering (1:1:1) defined consortium as inoculum, COD reduction was higher and yield of H{sub 2} was recorded to be 41.23 ml H{sub 2}/g COD{sub reduced}. Microbial profiling of the spent sludge showed that B. coagulans was the dominant member in the constructed consortium contributing towards H{sub 2} production. Increase in H{sub 2} yield indicated that in consortium, the substrate utilization was significantly higher. The H{sub 2} yield from pretreated sludge (35.54 ml H{sub 2}/g sludge) was comparatively higher than that reported in literature (8.1-16.9 ml H{sub 2}/g sludge). Employing formulated microbial consortium for biohydrogen production is a successful attempt to augment the H{sub 2} yield from sewage sludge. (author)

  11. Chlorine stress mediates microbial surface attachment in drinking water systems.

    Science.gov (United States)

    Liu, Li; Le, Yang; Jin, Juliang; Zhou, Yuliang; Chen, Guowei

    2015-03-01

    Microbial attachment to drinking water pipe surfaces facilitates pathogen survival and deteriorates disinfection performance, directly threatening the safety of drinking water. Notwithstanding that the formation of biofilm has been studied for decades, the underlying mechanisms for the origins of microbial surface attachment in biofilm development in drinking water pipelines remain largely elusive. We combined experimental and mathematical methods to investigate the role of environmental stress-mediated cell motility on microbial surface attachment in chlorination-stressed drinking water distribution systems. Results show that at low levels of disinfectant (0.0-1.0 mg/L), the presence of chlorine promotes initiation of microbial surface attachment, while higher amounts of disinfectant (>1.0 mg/L) inhibit microbial attachment. The proposed mathematical model further demonstrates that chlorination stress (0.0-5.0 mg/L)-mediated microbial cell motility regulates the frequency of cell-wall collision and thereby controls initial microbial surface attachment. The results reveal that transport processes and decay patterns of chlorine in drinking water pipelines regulate microbial cell motility and, thus, control initial surface cell attachment. It provides a mechanistic understanding of microbial attachment shaped by environmental disinfection stress and leads to new insights into microbial safety protocols in water distribution systems.

  12. Engineering microbial cell factories for the production of plant natural products: from design principles to industrial-scale production.

    Science.gov (United States)

    Liu, Xiaonan; Ding, Wentao; Jiang, Huifeng

    2017-07-19

    Plant natural products (PNPs) are widely used as pharmaceuticals, nutraceuticals, seasonings, pigments, etc., with a huge commercial value on the global market. However, most of these PNPs are still being extracted from plants. A resource-conserving and environment-friendly synthesis route for PNPs that utilizes microbial cell factories has attracted increasing attention since the 1940s. However, at the present only a handful of PNPs are being produced by microbial cell factories at an industrial scale, and there are still many challenges in their large-scale application. One of the challenges is that most biosynthetic pathways of PNPs are still unknown, which largely limits the number of candidate PNPs for heterologous microbial production. Another challenge is that the metabolic fluxes toward the target products in microbial hosts are often hindered by poor precursor supply, low catalytic activity of enzymes and obstructed product transport. Consequently, despite intensive studies on the metabolic engineering of microbial hosts, the fermentation costs of most heterologously produced PNPs are still too high for industrial-scale production. In this paper, we review several aspects of PNP production in microbial cell factories, including important design principles and recent progress in pathway mining and metabolic engineering. In addition, implemented cases of industrial-scale production of PNPs in microbial cell factories are also highlighted.

  13. Electricity production from microbial fuel cell by using yeast

    International Nuclear Information System (INIS)

    Vorasingha, A.; Souvakon, C.; Boonchom, K.

    2006-01-01

    The continuous search for methods to generate electricity from renewable sources such as water, solar energy, wind, nuclear or chemicals was discussed with particular focus on attaining the full power of the microbial fuel cell (MFC). Under ideal environmental conditions, the only byproducts of a biofuel cell would be water and carbon dioxide (CO 2 ). The production of energy from renewables such as biomass is important for sustainable development and reducing global emissions of CO 2 . Hydrogen can also be an important component of an energy infrastructure that reduces CO 2 emissions if the hydrogen is produced from renewable sources and used in fuel cells. Hydrogen gas can be biologically produced at high concentration from the fermentation of high sugar substrates such as glucose and sucrose. Some of the issues of MFC design were addressed, including the use of cheap substrates to derive microbial electricity. In the MFC, yeast donates electrons to a chemical electron mediator, which in turn transfers the electrons to an electrode, producing electricity. Experimental results showed that glucose yielded the highest peak voltage, but a semi-processed sugar and molasses were similar to glucose in the electricity production pattern. It was noted that this technology is only at the research stages, and more research is needed before household microbial fuel cells can be made available for producing power for prolonged periods of time. Future research efforts will focus on increasing the efficiency, finding alternatives to hazardous electron mediators and finding new microbes. 12 refs., 6 figs

  14. Production of Modularised Product Systems

    DEFF Research Database (Denmark)

    Jacobsen, Peter

    2004-01-01

    but a solution. Modularisation is one tool used in designing the products. Designing and controlling a production system making customized products in an economical way is not an easy task. In order to fulfil the Lean and Agile manufacturing philosophies the production is often carried out in networks. Here...

  15. Integrated microbial processes for biofuels and high value-added products: the way to improve the cost effectiveness of biofuel production.

    Science.gov (United States)

    da Silva, Teresa Lopes; Gouveia, Luísa; Reis, Alberto

    2014-02-01

    The production of microbial biofuels is currently under investigation, as they are alternative sources to fossil fuels, which are diminishing and their use has a negative impact on the environment. However, so far, biofuels derived from microbes are not economically competitive. One way to overcome this bottleneck is the use of microorganisms to transform substrates into biofuels and high value-added products, and simultaneously taking advantage of the various microbial biomass components to produce other products of interest, as an integrated process. In this way, it is possible to maximize the economic value of the whole process, with the desired reduction of the waste streams produced. It is expected that this integrated system makes the biofuel production economically sustainable and competitive in the near future. This review describes the investigation on integrated microbial processes (based on bacteria, yeast, and microalgal cultivations) that have been experimentally developed, highlighting the importance of this approach as a way to optimize microbial biofuel production process.

  16. Scaling up microbial fuel cells and other bioelectrochemical systems

    KAUST Repository

    Logan, Bruce E.

    2009-12-15

    Scientific research has advanced on different microbial fuel cell (MFC) technologies in the laboratory at an amazing pace, with power densities having reached over 1 kW/m3 (reactor volume) and to 6.9 W/m2 (anode area) under optimal conditions. The main challenge is to bring these technologies out of the laboratory and engineer practical systems for bioenergy production at larger scales. Recent advances in new types of electrodes, a better understanding of the impact of membranes and separators on performance of these systems, and results from several new pilot-scale tests are all good indicators that commercialization of the technology could be possible within a few years. Some of the newest advances and future challenges are reviewed here with respect to practical applications of these MFCs for renewable energy production and other applications. © 2009 Springer-Verlag.

  17. Scaling up microbial fuel cells and other bioelectrochemical systems

    KAUST Repository

    Logan, Bruce E.

    2009-01-01

    Scientific research has advanced on different microbial fuel cell (MFC) technologies in the laboratory at an amazing pace, with power densities having reached over 1 kW/m3 (reactor volume) and to 6.9 W/m2 (anode area) under optimal conditions. The main challenge is to bring these technologies out of the laboratory and engineer practical systems for bioenergy production at larger scales. Recent advances in new types of electrodes, a better understanding of the impact of membranes and separators on performance of these systems, and results from several new pilot-scale tests are all good indicators that commercialization of the technology could be possible within a few years. Some of the newest advances and future challenges are reviewed here with respect to practical applications of these MFCs for renewable energy production and other applications. © 2009 Springer-Verlag.

  18. Microbial ecology of terrestrial Antarctica: Are microbial systems at risk from human activities?

    Energy Technology Data Exchange (ETDEWEB)

    White, G.J.

    1996-08-01

    Many of the ecological systems found in continental Antarctica are comprised entirely of microbial species. Concerns have arisen that these microbial systems might be at risk either directly through the actions of humans or indirectly through increased competition from introduced species. Although protection of native biota is covered by the Protocol on Environmental Protection to the Antarctic Treaty, strict measures for preventing the introduction on non-native species or for protecting microbial habitats may be impractical. This report summarizes the research conducted to date on microbial ecosystems in continental Antarctica and discusses the need for protecting these ecosystems. The focus is on communities inhabiting soil and rock surfaces in non-coastal areas of continental Antarctica. Although current polices regarding waste management and other operations in Antarctic research stations serve to reduce the introduction on non- native microbial species, importation cannot be eliminated entirely. Increased awareness of microbial habitats by field personnel and protection of certain unique habitats from physical destruction by humans may be necessary. At present, small-scale impacts from human activities are occurring in certain areas both in terms of introduced species and destruction of habitat. On a large scale, however, it is questionable whether the introduction of non-native microbial species to terrestrial Antarctica merits concern.

  19. Submersible microbial fuel cell for electricity production from sewage sludge

    DEFF Research Database (Denmark)

    Zhang, Yifeng; Olias, Lola Gonzalez; Kongjan, Prawit

    2011-01-01

    A submersible microbial fuel cell (SMFC) was utilized to treat sewage sludge and simultaneously generate electricity. Stable power generation (145± 5 mW/m2, 470 Ω) was produced continuously from raw sewage sludge for 5.5 days. The maximum power density reached 190±5 mW/m2. The corresponding total...... system to treat sewage sludge and simultaneously recover energy....

  20. Microbial Production of l-Serine from Renewable Feedstocks.

    Science.gov (United States)

    Zhang, Xiaomei; Xu, Guoqiang; Shi, Jinsong; Koffas, Mattheos A G; Xu, Zhenghong

    2018-07-01

    l-Serine is a non-essential amino acid that has wide and expanding applications in industry with a fast-growing market demand. Currently, extraction and enzymatic catalysis are the main processes for l-serine production. However, such approaches limit the industrial-scale applications of this important amino acid. Therefore, shifting to the direct fermentative production of l-serine from renewable feedstocks has attracted increasing attention. This review details the current status of microbial production of l-serine from renewable feedstocks. We also summarize the current trends in metabolic engineering strategies and techniques for the typical industrial organisms Corynebacterium glutamicum and Escherichia coli that have been developed to address and overcome major challenges in the l-serine production process. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. Microbial production of nattokinase: current progress, challenge and prospect.

    Science.gov (United States)

    Cai, Dongbo; Zhu, Chengjun; Chen, Shouwen

    2017-05-01

    Nattokinase (EC 3.4.21.62) is a profibrinolytic serine protease with a potent fibrin-degrading activity, and it has been produced by many host strains. Compared to other fibrinolytic enzymes (urokinase, t-PA and streprokinase), nattokinase shows the advantages of having no side effects, low cost and long life-time, and it has the potential to be used as a drug for treating cardiovascular disease and served as a functional food additive. In this review, we focused on screening of producing strains, genetic engineering, fermentation process optimization for microbial nattokinase production, and the extraction and purification of nattokinase were also discussed in this particular chapter. The selection of optimal nattokinase producing strain was the crucial starting element for improvement of nattokinase production. Genetic engineering, protein engineering, fermentation optimization and process control have been proved to be the effective strategies for enhancement of nattokinase production. Also, extraction and purification of nattokinase are critical for the quality evaluation of nattokinase. Finally, the prospect of microbial nattokinase production was also discussed regarding the recent progress, challenge, and trends in this field.

  2. DESM: portal for microbial knowledge exploration systems

    KAUST Repository

    Salhi, Adil

    2015-11-05

    Microorganisms produce an enormous variety of chemical compounds. It is of general interest for microbiology and biotechnology researchers to have means to explore information about molecular and genetic basis of functioning of different microorganisms and their ability for bioproduction. To enable such exploration, we compiled 45 topic-specific knowledgebases (KBs) accessible through DESM portal (www.cbrc.kaust.edu.sa/desm). The KBs contain information derived through text-mining of PubMed information and complemented by information data-mined from various other resources (e.g. ChEBI, Entrez Gene, GO, KOBAS, KEGG, UniPathways, BioGrid). All PubMed records were indexed using 4 538 278 concepts from 29 dictionaries, with 1 638 986 records utilized in KBs. Concepts used are normalized whenever possible. Most of the KBs focus on a particular type of microbial activity, such as production of biocatalysts or nutraceuticals. Others are focused on specific categories of microorganisms, e.g. streptomyces or cyanobacteria. KBs are all structured in a uniform manner and have a standardized user interface. Information exploration is enabled through various searches. Users can explore statistically most significant concepts or pairs of concepts, generate hypotheses, create interactive networks of associated concepts and export results. We believe DESM will be a useful complement to the existing resources to benefit microbiology and biotechnology research.

  3. Bioelectricity Production from Microalgae-Microbial Fuel Cell Technology (MMFC

    Directory of Open Access Journals (Sweden)

    da Costa Carlito

    2018-01-01

    Full Text Available Microbial fuel cell is an ecological innovative technology producing bioelectricity by utilizing microbes activity. Substituent energy is produced by changing the chemical energy to electrical energy through the catalytic reaction of microorganism. The research aims to find out the potency of bioelectricity produced by microalgae microbial fuel cell technology by utilizing the combination of tapioca wastewater and microalgae cultivation. This research is conducted through the ingredients preparation stage – microalgae culture, wastewater characterization, membrane and graphite activation, and the providing of other supporting equipment. The next stage is the MMFC arrangement, while the last one is bioelectricity measurement. The result of optimal bioelectricity production on the comparison of electrode 2 : 2, the power density is 44,33 mW/m2 on day 6, meanwhile, on that of 1 : 1, 20,18 mW/m2 power density on day 1 is obtained. It shows that bioelectricity can be produced from the combination of tapioca wastewater and microalgae culture through the microalgae-microbial fuel cell (MMFC technology.This research is expected to be a reference for the next research particularly the one that observes the utilizing of microalgae as the part of new and renewable energy sources.

  4. Microbial reverse-electrodialysis chemical-production cell for acid and alkali production

    KAUST Repository

    Zhu, Xiuping

    2013-06-01

    A new type of bioelectrochemical system, called a microbial reverse-electrodialysis chemical-production cell (MRCC), was developed to produce acid and alkali using energy derived from organic matter (acetate) and salinity gradients (NaCl solutions representative of seawater and river water). A bipolar membrane (BPM) was placed next to the anode to prevent Cl- contamination and acidification of the anolyte, and to produce protons for HCl recovery. A 5-cell paired reverse-electrodialysis (RED) stack provided the electrical energy required to overcome the BPM over-potential (0.3-0.6 V), making the overall process spontaneous. The MRCC reactor produced electricity (908 mW/m2) as well as concentrated acidic and alkaline solutions, and therefore did not require an external power supply. After a fed-batch cycle, the pHs of the chemical product solutions were 1.65 ± 0.04 and 11.98 ± 0.10, due to the production of 1.35 ± 0.13 mmol of acid, and 0.59 ± 0.14 mmol of alkali. The acid- and alkali-production efficiencies based on generated current were 58 ± 3% and 25 ± 3%. These results demonstrated proof-of-concept acid and alkali production using only renewable energy sources. © 2013 Elsevier B.V.

  5. Unraveling the relationship between microbial translocation and systemic immune activation in HIV infection

    Science.gov (United States)

    Shan, Liang; Siliciano, Robert F.

    2014-01-01

    Chronic immune activation is a key factor in HIV-1 disease progression. The translocation of microbial products from the intestinal lumen into the systemic circulation occurs during HIV-1 infection and is associated closely with immune activation; however, it has not been determined conclusively whether microbial translocation drives immune activation or occurs as a consequence of HIV-1 infection. In an important study in this issue of the JCI, Kristoff and colleagues describe the role of microbial translocation in producing immune activation in an animal model of HIV-1 infection, SIV infection of pigtailed macaques. Blocking translocation of intestinal bacterial LPS into the circulation dramatically reduced T cell activation and proliferation, production of proinflammatory cytokines, and plasma SIV RNA levels. This study directly demonstrates that microbial translocation promotes the systemic immune activation associated with HIV-1/SIV infection. PMID:24837427

  6. Periodontitis: from microbial immune subversion to systemic inflammation

    Science.gov (United States)

    Hajishengallis, George

    2014-01-01

    Periodontitis is a dysbiotic inflammatory disease with an adverse impact on systemic health. Recent studies have provided insights into the emergence and persistence of dysbiotic oral microbial communities, which can mediate inflammatory pathology at local as well as distant sites. This Review discusses mechanisms of microbial immune subversion that tip the balance from homeostasis to disease in oral or extraoral sites. PMID:25534621

  7. Soil Microbial Activity in Conventional and Organic Agricultural Systems

    Directory of Open Access Journals (Sweden)

    Romero F.V. Carneiro

    2009-06-01

    Full Text Available The aim of this study was to evaluate microbial activity in soils under conventional and organic agricultural system management regimes. Soil samples were collected from plots under conventional management (CNV, organic management (ORG and native vegetation (AVN. Soil microbial activity and biomass was significantly greater in ORG compared with CNV. Soil bulk density decreased three years after adoption of organic system. Soil organic carbon (SOC was higher in the ORG than in the CNV. The soil under organic agricultural system presents higher microbial activity and biomass and lower bulk density than the conventional agricultural system.

  8. Microbial diversity in different compartments of an aquaponics system.

    Science.gov (United States)

    Schmautz, Zala; Graber, Andreas; Jaenicke, Sebastian; Goesmann, Alexander; Junge, Ranka; Smits, Theo H M

    2017-05-01

    Aquaponics is a solution for sustainable production of fish and plants in a single semi-closed system, where nutrient-rich water from the aquaculture provides nutrients for plant growth. We examined the microbial communities within an experimental aquaponics system. Whereas the fish feces contained a separate community dominated by bacteria of the genus Cetobacterium, the samples from plant roots, biofilter, and periphyton were more similar to each other, while the communities were more diverse. Detailed examination of the data gave the first indications to functional groups of organisms in the different compartments of the aquaponic system. As other nitrifiers other than members of the genus Nitrospira were only present at low numbers, it was anticipated that Nitrospirae may perform the nitrification process in the biofilm.

  9. Microbial status and product labelling of 58 original tattoo inks

    DEFF Research Database (Denmark)

    Høgsberg, T; Saunte, D M; Frimodt-møller, Niels

    2011-01-01

    and labelled according to REACH as if they were plain chemicals. Objective  The objective of this study was to check the microbial product safety of unopened and opened tattoo ink stock bottles. Packaging, labelling, preservation, sterility and contamination with micro-organisms were studied. Methods  Physical......-pathogenic environmental bacteria. Yeast or moulds were detected in none of the samples. A total of 31% of the manufacturers informed only about the brand name. No information about content, sterility, risks or expiry date was indicated on the label. A total of 42% claimed sterility of their inks. A total of 54% labelled...

  10. Metabolic modelling of polyhydroxyalkanoate copolymers production by mixed microbial cultures

    Directory of Open Access Journals (Sweden)

    Reis Maria AM

    2008-07-01

    Full Text Available Abstract Background This paper presents a metabolic model describing the production of polyhydroxyalkanoate (PHA copolymers in mixed microbial cultures, using mixtures of acetic and propionic acid as carbon source material. Material and energetic balances were established on the basis of previously elucidated metabolic pathways. Equations were derived for the theoretical yields for cell growth and PHA production on mixtures of acetic and propionic acid as functions of the oxidative phosphorylation efficiency, P/O ratio. The oxidative phosphorylation efficiency was estimated from rate measurements, which in turn allowed the estimation of the theoretical yield coefficients. Results The model was validated with experimental data collected in a sequencing batch reactor (SBR operated under varying feeding conditions: feeding of acetic and propionic acid separately (control experiments, and the feeding of acetic and propionic acid simultaneously. Two different feast and famine culture enrichment strategies were studied: (i either with acetate or (ii with propionate as carbon source material. Metabolic flux analysis (MFA was performed for the different feeding conditions and culture enrichment strategies. Flux balance analysis (FBA was used to calculate optimal feeding scenarios for high quality PHA polymers production, where it was found that a suitable polymer would be obtained when acetate is fed in excess and the feeding rate of propionate is limited to ~0.17 C-mol/(C-mol.h. The results were compared with published pure culture metabolic studies. Conclusion Acetate was more conducive toward the enrichment of a microbial culture with higher PHA storage fluxes and yields as compared to propionate. The P/O ratio was not only influenced by the selected microbial culture, but also by the carbon substrate fed to each culture, where higher P/O ratio values were consistently observed for acetate than propionate. MFA studies suggest that when mixtures of

  11. Development of a High Temperature Microbial Fermentation Processfor Butanol Production

    International Nuclear Information System (INIS)

    Jeor, Jeffery D.; Reed, David W.; Daubaras, Dayna L.; Thompson, Vicki S.

    2016-01-01

    Transforming renewable biomass into cost competitive high-performance biofuels and bioproducts is key to US energy security. Butanol production by microbial fermentation and chemical conversion to polyolefins, elastomers, drop-in jet or diesel fuel, and other chemicals is a promising solution. A high temperature fermentation process can facilitate butanol recovery up to 40%, by using gas stripping. Other benefits of fermentation at high temperatures are optimal hydrolysis rates in the saccharification of biomass which leads to maximized butanol production, decrease in energy costs associated with reactor cooling and capital cost associated with reactor design, and a decrease in contamination and cost for maintaining a sterile environment. Butanol stripping at elevated temperatures gives higher butanol production through constant removal and continuous fermentation. We describe methods used in an attempt to genetically prepare Geobacillus caldoxylosiliticus for insertion of a butanol pathway. Methods used were electroporation of electrocompetent cells, ternary conjugation with E. coli, and protoplast fusion.

  12. Dereplication of Microbial Natural Products by LC-DAD-TOFMS

    DEFF Research Database (Denmark)

    Nielsen, Kristian Fog; Månsson, Maria; Rank, Christian

    2011-01-01

    Dereplication, the rapid identification of known compounds present in a mixture, is crucial to the fast discovery of novel natural products. Determining the elemental composition of compounds in mixtures and tentatively identifying natural products using MS/MS and UV/vis spectra is becoming easier...... with advances in analytical equipment and better compound databases. Here we demonstrate the use of LC-UV/vis-MS-based dereplication using data from UV/vis diode array detection and ESI+/ESI– time-of-flight MS for assignment of 719 microbial natural product and mycotoxin reference standards. ESI+ was the most...... unambiguously using multiple adduct ions, while a further 41% of the compounds were detected only as [M – H]−. The most reliable interpretations of conflicting ESI+ and ESI– data on a chromatographic peak were from the ionization polarity with the most intense ionization. Poor ionization was most common...

  13. Development of a High Temperature Microbial Fermentation Processfor Butanol Production

    Energy Technology Data Exchange (ETDEWEB)

    Jeor, Jeffery D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Reed, David W. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Daubaras, Dayna L. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Thompson, Vicki S. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-06-01

    Transforming renewable biomass into cost competitive high-performance biofuels and bioproducts is key to US energy security. Butanol production by microbial fermentation and chemical conversion to polyolefins, elastomers, drop-in jet or diesel fuel, and other chemicals is a promising solution. A high temperature fermentation process can facilitate butanol recovery up to 40%, by using gas stripping. Other benefits of fermentation at high temperatures are optimal hydrolysis rates in the saccharification of biomass which leads to maximized butanol production, decrease in energy costs associated with reactor cooling and capital cost associated with reactor design, and a decrease in contamination and cost for maintaining a sterile environment. Butanol stripping at elevated temperatures gives higher butanol production through constant removal and continuous fermentation. We describe methods used in an attempt to genetically prepare Geobacillus caldoxylosiliticus for insertion of a butanol pathway. Methods used were electroporation of electrocompetent cells, ternary conjugation with E. coli, and protoplast fusion.

  14. A new approach to microbial production of gallic acid.

    Science.gov (United States)

    Bajpai, Bhakti; Patil, Shridhar

    2008-10-01

    In a new approach to microbial gallic acid production by Aspergillus fischeri MTCC 150, 40gL(-1) of tannic acid was added in two installments during the bioconversion phase of the process (25gL(-1) and 15gL(-1) at 32 and 44h respectively). The optimum parameters for the bioconversion phase were found to be temperature: 35°C, pH: slightly acidic (3.3-3.5), aeration: nil and agitation: 250 rpm. A maximum of 71.4% conversion was obtained after 71h fermentation with 83.3% product recovery. The yield was 7.35 g of gallic acid per g of biomass accumulated and the fermenter productivity was 0.56 g of gallic acid produced per liter of medium per hour.

  15. Product Service Systems

    DEFF Research Database (Denmark)

    Departing from Product Development models based on physical artefacts. Moving towards integrated Product Development and System Operations models suited Product/Service-systems......Departing from Product Development models based on physical artefacts. Moving towards integrated Product Development and System Operations models suited Product/Service-systems...

  16. Whey-derived valuable products obtained by microbial fermentation.

    Science.gov (United States)

    Pescuma, Micaela; de Valdez, Graciela Font; Mozzi, Fernanda

    2015-08-01

    Whey, the main by-product of the cheese industry, is considered as an important pollutant due to its high chemical and biological oxygen demand. Whey, often considered as waste, has high nutritional value and can be used to obtain value-added products, although some of them need expensive enzymatic synthesis. An economical alternative to transform whey into valuable products is through bacterial or yeast fermentations and by accumulation during algae growth. Fermentative processes can be applied either to produce individual compounds or to formulate new foods and beverages. In the first case, a considerable amount of research has been directed to obtain biofuels able to replace those derived from petrol. In addition, the possibility of replacing petrol-derived plastics by biodegradable polymers synthesized during bacterial fermentation of whey has been sought. Further, the ability of different organisms to produce metabolites commonly used in the food and pharmaceutical industries (i.e., lactic acid, lactobionic acid, polysaccharides, etc.) using whey as growth substrate has been studied. On the other hand, new low-cost functional whey-based foods and beverages leveraging the high nutritional quality of whey have been formulated, highlighting the health-promoting effects of fermented whey-derived products. This review aims to gather the multiple uses of whey as sustainable raw material for the production of individual compounds, foods, and beverages by microbial fermentation. This is the first work to give an overview on the microbial transformation of whey as raw material into a large repertoire of industrially relevant foods and products.

  17. Microbial decontamination of cosmetic products by gamma irradiation

    International Nuclear Information System (INIS)

    Taha, S.M.A.

    2010-01-01

    The microbiological quality of cosmetic products (skin creams, massage gels and hair lotion) and the effect of gamma irradiation on this quality were investigated.The effectiveness of these cosmetic products with the tested pathogenic microorganisms was also examined. Total bacterial counts (TBC) of examined cosmetic products ranged between 5 cfu/g or ml. Most cosmetic products evaluated were free from mold and yeast. Spore forming bacteria (SFB) were low and ranged between 2 cfu/g or ml. The enterobacteriaceae (Ent) group was generally absent from the examined cosmetic products except for one sample (varic, skin cream) which contained 7x10 3 cfu/g. All cosmetic products studied were free from Pseudomonas species, Aeromonas hydrophila; Bacillus cereus; Listeria monocytogenes and Salmonella species. Only one sample (varic, skin cream) contained E. coli (2x10 2 cfu/g). Enterococcus faecalis was found in three samples of cosmetic products tested (maxi care, panol and varic creams) and the counts were 7x10 2 , 2x10 2 and 5x10 4 cfu/g, respectively. Also Staphylococcus aureus was found in the same three samples and the counts were in the range of 2-3x10 2 cfu/g. The effectiveness of cosmetic products with the tested pathogenic bacteria differs according to the type of cosmetic products examined . The irradiation dose of 6 kGy was very effective in microbial decontamination and elimination of pathogenic bacteria in cosmetic products for enhancing health quality and ensuring safety of these products.

  18. Recent Advances in Microbial Production of Aromatic Chemicals and Derivatives.

    Science.gov (United States)

    Noda, Shuhei; Kondo, Akihiko

    2017-08-01

    Along with the development of metabolic engineering and synthetic biology tools, various microbes are being used to produce aromatic chemicals. In microbes, aromatics are mainly produced via a common important precursor, chorismate, in the shikimate pathway. Natural or non-natural aromatics have been produced by engineering metabolic pathways involving chorismate. In the past decade, novel approaches have appeared to produce various aromatics or to increase their productivity, whereas previously, the targets were mainly aromatic amino acids and the strategy was deregulating feedback inhibition. In this review, we summarize recent studies of microbial production of aromatics based on metabolic engineering approaches. In addition, future perspectives and challenges in this research area are discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Antimicrobial Materials for Advanced Microbial Control in Spacecraft Water Systems

    Science.gov (United States)

    Birmele, Michele; Caro, Janicce; Newsham, Gerard; Roberts, Michael; Morford, Megan; Wheeler, Ray

    2012-01-01

    Microbial detection, identification, and control are essential for the maintenance and preservation of spacecraft water systems. Requirements set by NASA put limitations on the energy, mass, materials, noise, cost, and crew time that can be devoted to microbial control. Efforts are being made to attain real-time detection and identification of microbial contamination in microgravity environments. Research for evaluating technologies for capability enhancement on-orbit is currently focused on the use of adenosine triphosphate (ATP) analysis for detection purposes and polymerase chain reaction (peR) for microbial identification. Additional research is being conducted on how to control for microbial contamination on a continual basis. Existing microbial control methods in spacecraft utilize iodine or ionic silver biocides, physical disinfection, and point-of-use sterilization filters. Although these methods are effective, they require re-dosing due to loss of efficacy, have low human toxicity thresholds, produce poor taste, and consume valuable mass and crew time. Thus, alternative methods for microbial control are needed. This project also explores ultraviolet light-emitting diodes (UV-LEDs), surface passivation methods for maintaining residual biocide levels, and several antimicrobial materials aimed at improving current microbial control techniques, as well as addressing other materials presently under analysis and future directions to be pursued.

  20. Automated DNA extraction platforms offer solutions to challenges of assessing microbial biofouling in oil production facilities.

    Science.gov (United States)

    Oldham, Athenia L; Drilling, Heather S; Stamps, Blake W; Stevenson, Bradley S; Duncan, Kathleen E

    2012-11-20

    The analysis of microbial assemblages in industrial, marine, and medical systems can inform decisions regarding quality control or mitigation. Modern molecular approaches to detect, characterize, and quantify microorganisms provide rapid and thorough measures unbiased by the need for cultivation. The requirement of timely extraction of high quality nucleic acids for molecular analysis is faced with specific challenges when used to study the influence of microorganisms on oil production. Production facilities are often ill equipped for nucleic acid extraction techniques, making the preservation and transportation of samples off-site a priority. As a potential solution, the possibility of extracting nucleic acids on-site using automated platforms was tested. The performance of two such platforms, the Fujifilm QuickGene-Mini80™ and Promega Maxwell®16 was compared to a widely used manual extraction kit, MOBIO PowerBiofilm™ DNA Isolation Kit, in terms of ease of operation, DNA quality, and microbial community composition. Three pipeline biofilm samples were chosen for these comparisons; two contained crude oil and corrosion products and the third transported seawater. Overall, the two more automated extraction platforms produced higher DNA yields than the manual approach. DNA quality was evaluated for amplification by quantitative PCR (qPCR) and end-point PCR to generate 454 pyrosequencing libraries for 16S rRNA microbial community analysis. Microbial community structure, as assessed by DGGE analysis and pyrosequencing, was comparable among the three extraction methods. Therefore, the use of automated extraction platforms should enhance the feasibility of rapidly evaluating microbial biofouling at remote locations or those with limited resources.

  1. Soil microbial communities under cacao agroforestry and cover crop systems in Peru

    Science.gov (United States)

    Cacao (Theobroma cacao) trees are grown in tropical regions worldwide for chocolate production. We studied the effects of agroforestry management systems and cover cropping on soil microbial communities under cacao in two different replicated field experiments in Peru. Two agroforestry systems, Imp...

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

    Science.gov (United States)

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

    2015-05-01

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

  3. Microbial Electrodialysis Cell for Simultaneous Water Desalination and Hydrogen Gas Production

    KAUST Repository

    Mehanna, Maha; Kiely, Patrick D.; Call, Douglas F.; Logan, Bruce. E.

    2010-01-01

    A new approach to water desalination is to use exoelectrogenic bacteria to generate electrical power from the biodegradation of organic matter, moving charged ions from a middle chamber between two membranes in a type of microbial fuel cell called a microbial desalination cell. Desalination efficiency using this approach is limited by the voltage produced by the bacteria. Here we examine an alternative strategy based on boosting the voltage produced by the bacteria to achieve hydrogen gas evolution from the cathode using a three-chambered system we refer to as a microbial electrodialysis cell (MEDC). We examined the use of the MEDC process using two different initial NaCl concentrations of 5 g/L and 20 g/L. Conductivity in the desalination chamber was reduced by up to 68 ± 3% in a single fed-batch cycle, with electrical energy efficiencies reaching 231 ± 59%, and maximum hydrogen production rates of 0.16 ± 0.05 m3 H2/m3 d obtained at an applied voltage of 0.55 V. The advantage of this system compared to a microbial fuel cell approach is that the potentials between the electrodes can be better controlled, and the hydrogen gas that is produced can be used to recover energy to make the desalination process self-sustaining with respect to electrical power requirements. © 2010 American Chemical Society.

  4. Microbial Electrodialysis Cell for Simultaneous Water Desalination and Hydrogen Gas Production

    KAUST Repository

    Mehanna, Maha

    2010-12-15

    A new approach to water desalination is to use exoelectrogenic bacteria to generate electrical power from the biodegradation of organic matter, moving charged ions from a middle chamber between two membranes in a type of microbial fuel cell called a microbial desalination cell. Desalination efficiency using this approach is limited by the voltage produced by the bacteria. Here we examine an alternative strategy based on boosting the voltage produced by the bacteria to achieve hydrogen gas evolution from the cathode using a three-chambered system we refer to as a microbial electrodialysis cell (MEDC). We examined the use of the MEDC process using two different initial NaCl concentrations of 5 g/L and 20 g/L. Conductivity in the desalination chamber was reduced by up to 68 ± 3% in a single fed-batch cycle, with electrical energy efficiencies reaching 231 ± 59%, and maximum hydrogen production rates of 0.16 ± 0.05 m3 H2/m3 d obtained at an applied voltage of 0.55 V. The advantage of this system compared to a microbial fuel cell approach is that the potentials between the electrodes can be better controlled, and the hydrogen gas that is produced can be used to recover energy to make the desalination process self-sustaining with respect to electrical power requirements. © 2010 American Chemical Society.

  5. Choosing the right platform for the right product: Sustainable production of chemicals in microbial cell factories

    DEFF Research Database (Denmark)

    Herrgard, Markus

    The Novo Nordisk Foundation Center for Biosustainability (CFB) is a new non-profit research center focused on sustainable production of biochemicals and therapeutic proteins using microbial and mammalian cell factories. The work at CFB is organized around an iterative loop where cell factories...

  6. Biodiesel production from microbial granules in sequencing batch reactor.

    Science.gov (United States)

    Liu, Lin; Hong, Yuling; Ye, Xin; Wei, Lili; Liao, Jie; Huang, Xu; Liu, Chaoxiang

    2018-02-01

    Effect of reaction variables of in situ transesterification on the biodiesel production, and the characteristic differences of biodiesel obtained from aerobic granular sludge (AG) and algae-bacteria granular consortia (AAG) were investigated. The results indicated that the effect of variables on the biodiesel yield decreased in the order of methanol quantity > catalyst concentration > reaction time, yet the parameters change will not significantly affect biodiesel properties. The maximum biodiesel yield of AAG was 66.21 ± 1.08 mg/g SS, what is significant higher than that of AG (35.44 ± 0.92 mg/g SS). Although methyl palmitate was the dominated composition of biodiesel obtained from both granules, poly-unsaturated fatty acid in the AAG showed a higher percentage (21.86%) than AG (1.2%) due to Scenedesmus addition. Further, microbial analysis confirmed that the composition of biodiesel obtained from microbial granules was also determined by bacterial community, and Xanthomonadaceae and Rhodobacteraceae were the dominant bacteria of AG and AAG, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Microbial Conversion of Waste Glycerol from Biodiesel Production into Value-Added Products

    Directory of Open Access Journals (Sweden)

    Hong Liu

    2013-09-01

    Full Text Available Biodiesel has gained a significant amount of attention over the past decade as an environmentally friendly fuel that is capable of being utilized by a conventional diesel engine. However, the biodiesel production process generates glycerol-containing waste streams which have become a disposal issue for biodiesel plants and generated a surplus of glycerol. A value-added opportunity is needed in order to compensate for disposal-associated costs. Microbial conversions from glycerol to valuable chemicals performed by various bacteria, yeast, fungi, and microalgae are discussed in this review paper, as well as the possibility of extending these conversions to microbial electrochemical technologies.

  8. Reproducible analyses of microbial food for advanced life support systems

    Science.gov (United States)

    Petersen, Gene R.

    1988-01-01

    The use of yeasts in controlled ecological life support systems (CELSS) for microbial food regeneration in space required the accurate and reproducible analysis of intracellular carbohydrate and protein levels. The reproducible analysis of glycogen was a key element in estimating overall content of edibles in candidate yeast strains. Typical analytical methods for estimating glycogen in Saccharomyces were not found to be entirely aplicable to other candidate strains. Rigorous cell lysis coupled with acid/base fractionation followed by specific enzymatic glycogen analyses were required to obtain accurate results in two strains of Candida. A profile of edible fractions of these strains was then determined. The suitability of yeasts as food sources in CELSS food production processes is discussed.

  9. Microbial lipid production: screening with yeasts grown on Brazilian molasses.

    Science.gov (United States)

    Vieira, J P F; Ienczak, J L; Rossell, C E V; Pradella, J G C; Franco, T T

    2014-12-01

    Rhodotorula glutinis CCT 2182, Rhodosporidium toruloides CCT 0783, Rhodotorula minuta CCT 1751 and Lipomyces starkeyi DSM 70296 were evaluated for the conversion of sugars from Brazilian molasses into single-cell oil (SCO) feedstock for biodiesel. Pulsed fed-batch fermentations were performed in 1.65 l working volume bioreactors. The maximum specific growth rate (µmax), lipid productivity (Pr) and cellular lipid content were, respectively, 0.23 h(-1), 0.41 g l(-1) h(-1), and 41% for Rsp. toruloides; 0.20 h(-1), 0.27 g l(-1) h(-1), and 36% for Rta. glutinis; 0.115 h(-1), 0.135 g l(-1) h(-1), and 27 % for Rta. minuta; and 0.11 h(-1), 0.13 g l(-1) h(-1), and 32% for L. starkeyi. Based on their microbial lipid productivity, content, and profile, Rsp. toruloides and Rta. glutinis are promising candidates for biodiesel production from Brazilian molasses. All the oils from the yeasts were similar to the composition of plant oils (rapeseed and soybean) and could be used as raw material for biofuels, as well as in food and nutraceutical products.

  10. Microbial decontamination of some chicken meat products by gamma irradiation

    International Nuclear Information System (INIS)

    Afifi, E.A.; El-Nashaby, F.M.

    2001-01-01

    This investigation aims to study the possibility of using gamma irradiation for microbial decontamination of some chicken meat products (Luncheon, Burger and debonded minced chicken) which are produced by three companies (Halwany Bros.(H)-Faragalla (F) and Egypco (E)). The samples were purchased from local supermarkets and examined for the presence of Salmonella spp. and Staphylococcus aureus. The examination illustrated that all examined samples were positive for Staphylococcus aureus. While Luncheon (F), Burger (H) and debonded minced chicken (E) were only positive for Salmonella spp. Therefore, these product samples were gamma irradiated at 0, 3, 6 and 9 kGy. The effects of radiation treatments and cold storage (5+,-1 degree) on the total volatile basic nitrogen (T.V.B.N.), microbiological quality and sensory properties of samples under investigation were studied. The results indicated that 3kGy dose of gamma irradiation completely destroyed Staphylococcus aureus and Salmonella spp. and caused slight increase in (T.V.B.N.) content for all samples. A gradual increase in total bacteria, molds and yeast and T. V. B. N. during storage were observed, while 6 kGy dose was also sufficient for destroying Salmonella spp. and Staphylococcus aureus in all chicken meat products under investigation without any detectable effects on the sensory properties of these products and increased the shelf-life of luncheon, burger and minced for 8, 4 and 3 weeks respectively as compared with 4, 2 and 1 weeks for control samples

  11. Microbial production of antioxidant food ingredients via metabolic engineering.

    Science.gov (United States)

    Lin, Yuheng; Jain, Rachit; Yan, Yajun

    2014-04-01

    Antioxidants are biological molecules with the ability to protect vital metabolites from harmful oxidation. Due to this fascinating role, their beneficial effects on human health are of paramount importance. Traditional approaches using solvent-based extraction from food/non-food sources and chemical synthesis are often expensive, exhaustive, and detrimental to the environment. With the advent of metabolic engineering tools, the successful reconstitution of heterologous pathways in Escherichia coli and other microorganisms provides a more exciting and amenable alternative to meet the increasing demand of natural antioxidants. In this review, we elucidate the recent progress in metabolic engineering efforts for the microbial production of antioxidant food ingredients - polyphenols, carotenoids, and antioxidant vitamins. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. 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.

  13. Feasibility of biohydrogen production from industrial wastes using defined microbial co-culture

    Directory of Open Access Journals (Sweden)

    Peng Chen

    2015-01-01

    Full Text Available BACKGROUND: The development of clean or novel alternative energy has become a global trend that will shape the future of energy. In the present study, 3 microbial strains with different oxygen requirements, including Clostridium acetobutylicum ATCC 824, Enterobacter cloacae ATCC 13047 and Kluyveromyces marxianus 15D, were used to construct a hydrogen production system that was composed of a mixed aerobic-facultative anaerobic-anaerobic consortium. The effects of metal ions, organic acids and carbohydrate substrates on this system were analyzed and compared using electrochemical and kinetic assays. It was then tested using small-scale experiments to evaluate its ability to convert starch in 5 L of organic wastewater into hydrogen. For the one-step biohydrogen production experiment, H1 medium (nutrient broth and potato dextrose broth was mixed directly with GAM broth to generate H2 medium (H1 medium and GAM broth. Finally, Clostridium acetobutylicum ATCC 824, Enterobacter cloacae ATCC 13047 and Kluyveromyces marxianus 15D of three species microbial co-culture to produce hydrogen under anaerobic conditions. For the two-step biohydrogen production experiment, the H1 medium, after cultured the microbial strains Enterobacter cloacae ATCC 13047 and Kluyveromyces marxianus 15D, was centrifuged to remove the microbial cells and then mixed with GAM broth (H2 medium. Afterward, the bacterial strain Clostridium acetobutylicum ATCC 824 was inoculated into the H2 medium to produce hydrogen by anaerobic fermentation. RESULTS: The experimental results demonstrated that the optimum conditions for the small-scale fermentative hydrogen production system were at pH 7.0, 35°C, a mixed medium, including H1 medium and H2 medium with 0.50 mol/L ferrous chloride, 0.50 mol/L magnesium sulfate, 0.50 mol/L potassium chloride, 1% w/v citric acid, 5% w/v fructose and 5% w/v glucose. The overall hydrogen production efficiency in the shake flask fermentation group was 33.7 m

  14. Strategies to diagnose and control microbial souring in natural gas storage reservoirs and produced water systems

    Energy Technology Data Exchange (ETDEWEB)

    Morris, E.A.; Derr, R.M.; Pope, D.H.

    1995-12-31

    Hydrogen sulfide production (souring) in natural gas storage reservoirs and produced water systems is a safety and environmental problem that can lead to operational shutdown when local hydrogen sulfide standards are exceeded. Systems affected by microbial souring have historically been treated using biocides that target the general microbial community. However, requirements for more environmentally friendly solutions have led to treatment strategies in which sulfide production can be controlled with minimal impact to the system and environment. Some of these strategies are based on microbial and/or nutritional augmentation of the sour environment. Through research sponsored by the Gas Research Institute (GRI) in Chicago, Illinois, methods have been developed for early detection of microbial souring in natural gas storage reservoirs, and a variety of mitigation strategies have been evaluated. The effectiveness of traditional biocide treatment in gas storage reservoirs was shown to depend heavily on the methods by which the chemical is applied. An innovative strategy using nitrate was tested and proved ideal for produced water and wastewater systems. Another strategy using elemental iodine was effective for sulfide control in evaporation ponds and is currently being tested in microbially sour natural gas storage wells.

  15. Microbial liquefaction of peat for the production of synthetic fuels

    Energy Technology Data Exchange (ETDEWEB)

    Gunasekaran, M.

    1988-01-01

    Objectives of this study were: to evaluate the potential of using various microorganisms to hydrolyse and liquify peat; to determine the optimal conditions for peat hydrolysis and liquefaction; to study the co-metabolizable substances; to separate the compounds present in liquified peat by alumina and silica acid chromatography and capillary gas chromatography; and to identify the compounds in liquified peat by capillary GC-Mass spectrometry. Organisms used in the study include: Coprinus comatus, Coriolus hirsutus, Ganoderma lucidum, Lentinus edodes, Lenzites trabea, Phanerochaete chrysosporium, Pleurotus ostreatus, P. sapidus, Polyporus adjustus, Neurospora sitophila, Rhizophus arrhizus, Bacillus subtilis, Acinetobacter sp. and Alcaligenes sp. The fungi were maintained and cultivated in potato dextrose agar at 30 C. The bacteria were maintained in nutrient agar at 30 C. We have also initiated work on coal solubilization in addition to the studies on peat liquefaction. A relatively new substratum or semi-solid base for culture media called Pluronic F-127, or Polyol (BASF, New Jersey). Objectives of this study were: (1) to study the growth patterns of Candida ML 13 on pluronic as substratum; (2) to determine the rate of microbial coal solubilization on pluronic F-127 amended in different growth media; (3) to separate the mycelial mat of Candida ML 13 from unsolubilized coal particles and solubilized coal products from pluronic F-127; (4) to determine the effects of pH on microbial coal solubilization in pluronic F-127 media; (5) the effect of concentration of pluronic F-127 in media on coal solubilization; and, (6) to study the role of extracellular factors secreted by Candida ML 13 on coal solubilization in pluronic F-127 media. Results are discussed. 4 refs.

  16. Relevance of microbial finished product testing in food safety management

    DEFF Research Database (Denmark)

    Zwietering, Marcel H.; Jacxsens, Liesbeth; Membré, Jeanne Marie

    2016-01-01

    Management of microbiological food safety is largely based on good design of processes, products and procedures. Finished product testing may be considered as a control measure at the end of the production process. However, testing gives only very limited information on the safety status of a food......-active way by implementing an effective food safety management system. For verification activities in a food safety management system, finished product testing may however be useful. For three cases studies; canned food, chocolate and cooked ham, the relevance of testing both of finished products....... If a hazardous organism is found it means something, but absence in a limited number of samples is no guarantee of safety of a whole production batch. Finished product testing is often too little and too late. Therefore most attention should be focussed on management and control of the hazards in a more pro...

  17. Renewable sustainable biocatalyzed electricity production in a photosynthetic algal microbial fuel cell (PAMFC)

    Energy Technology Data Exchange (ETDEWEB)

    Strik, David P.B.T.B.; Terlouw, Hilde; Hamelers, Hubertus V.M.; Buisman, Cees J.N. [Wageningen Univ. (Netherlands). Sub-Dept. of Environmental Technology

    2008-12-15

    Electricity production via solar energy capturing by living higher plants and microalgae in combination with microbial fuel cells are attractive because these systems promise to generate useful energy in a renewable, sustainable, and efficient manner. This study describes the proof of principle of a photosynthetic algal microbial fuel cell (PAMFC) based on naturally selected algae and electrochemically active microorganisms in an open system and without addition of instable or toxic mediators. The developed solar-powered PAMFC produced continuously over 100 days renewable biocatalyzed electricity. The sustainable performance of the PAMFC resulted in a maximum current density of 539 mA/m{sup 2} projected anode surface area and a maximum power production of 110 mW/m{sup 2} surface area photobioreactor. The energy recovery of the PAMFC can be increased by optimization of the photobioreactor, by reducing the competition from non-electrochemically active microorganisms, by increasing the electrode surface and establishment of a further-enriched biofilm. Since the objective is to produce net renewable energy with algae, future research should also focus on the development of low energy input PAMFCs. This is because current algae production systems have energy inputs similar to the energy present in the outcoming valuable products. (orig.)

  18. Renewable sustainable biocatalyzed electricity production in a photosynthetic algal microbial fuel cell (PAMFC).

    Science.gov (United States)

    Strik, David P B T B; Terlouw, Hilde; Hamelers, Hubertus V M; Buisman, Cees J N

    2008-12-01

    Electricity production via solar energy capturing by living higher plants and microalgae in combination with microbial fuel cells are attractive because these systems promise to generate useful energy in a renewable, sustainable, and efficient manner. This study describes the proof of principle of a photosynthetic algal microbial fuel cell (PAMFC) based on naturally selected algae and electrochemically active microorganisms in an open system and without addition of instable or toxic mediators. The developed solar-powered PAMFC produced continuously over 100 days renewable biocatalyzed electricity. The sustainable performance of the PAMFC resulted in a maximum current density of 539 mA/m2 projected anode surface area and a maximum power production of 110 mW/m2 surface area photobioreactor. The energy recovery of the PAMFC can be increased by optimization of the photobioreactor, by reducing the competition from non-electrochemically active microorganisms, by increasing the electrode surface and establishment of a further-enriched biofilm. Since the objective is to produce net renewable energy with algae, future research should also focus on the development of low energy input PAMFCs. This is because current algae production systems have energy inputs similar to the energy present in the outcoming valuable products.

  19. Soil microbial activity under conventional and organic production of bean and maize

    Directory of Open Access Journals (Sweden)

    Marinković Jelena B.

    2016-01-01

    Full Text Available The objective of this study was to compare the effects of conventional and organic production system on microbial activity in the soil cultivated with bean and maize crops. The trial in Đurđevo was set up according to the conventional farming system, while organic farming system was used in Futog. Two maize hybrids and two bean cultivars were used in the trial. Soil samples were collected in two periods during 2014 (before sowing, at flowering stage of bean crops, and at 9-11 leaf stage of maize at two depths, at both locations. The following microbiological parameters were tested: the total number of micro­organisms, number of ammonifiers, Azotobacter sp., free nitrogen fixing bacteria, fungi, actinomycetes, and activity of dehydrogenase enzyme. The results showed that the total number of microorganisms, number of free N-fixers and dehydrogenase activity were higher within organic production, while Azotobacter sp. was more abundant in conventional production. Variations in the number of ammonifiers, fungi and actinomycetes in relation to the type of production were not obtained. Significant differences in microbial activity were also obtained between period and depths of sampling.

  20. Colloquium and Report on Systems Microbiology: Beyond Microbial Genomics

    Energy Technology Data Exchange (ETDEWEB)

    Merry R. Buckley

    2004-12-13

    The American Academy of Microbiology convened a colloquium June 4-6, 2004 to confer about the scientific promise of systems microbiology. Participants discussed the power of applying a systems approach to the study of biology and to microbiology in particular, specifics about current research efforts, technical bottlenecks, requirements for data acquisition and maintenance, educational needs, and communication issues surrounding the field. A number of recommendations were made for removing barriers to progress in systems microbiology and for improving opportunities in education and collaboration. Systems biology, as a concept, is not new, but the recent explosion of genomic sequences and related data has revived interest in the field. Systems microbiology, a subset of systems biology, represents a different approach to investigating biological systems. It attempts to examine the emergent properties of microorganisms that arise from the interplay of genes, proteins, other macromolecules, small molecules, organelles, and the environment. It is these interactions, often nonlinear, that lead to the emergent properties of biological systems that are generally not tractable by traditional approaches. As a complement to the long-standing trend toward reductionism, systems microbiology seeks to treat the organism or community as a whole, integrating fundamental biological knowledge with genomics, metabolomics, and other data to create an integrated picture of how a microbial cell or community operates. Systems microbiology promises not only to shed light on the activities of microbes, but will also provide biology the tools and approaches necessary for achieving a better understanding of life and ecosystems. Microorganisms are ideal candidates for systems biology research because they are relatively easy to manipulate and because they play critical roles in health, environment, agriculture, and energy production. Potential applications of systems microbiology research

  1. Long-term effects of potato cropping system strategies on soilborne diseases and soil microbial communities

    Science.gov (United States)

    Cropping systems incorporating soil health management practices, such as longer rotations, disease-suppressive crops, reduced tillage, and/or organic amendments can substantially affect soil microbial communities, and potentially reduce soilborne potato diseases and increase productivity, but long-t...

  2. Monitoring the Perturbation of Soil and Groundwater Microbial Communities Due to Pig Production Activities

    KAUST Repository

    Hong, Pei-Ying; Yannarell, A. C.; Dai, Q.; Ekizoglu, M.; Mackie, R. I.

    2013-01-01

    This study aimed to determine if biotic contaminants originating from pig production farms are disseminated into soil and groundwater microbial communities. A spatial and temporal sampling of soil and groundwater in proximity to pig production farms

  3. Continuous power generation and microbial community structure of the anode biofilms in a three-stage microbial fuel cell system

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Kyungmi; Okabe, Satoshi [Hokkaido Univ., Sapporo (Japan). Dept. of Urban and Environmental Engineering

    2009-07-15

    A mediator-less three-stage two-chamber microbial fuel cell (MFC) system was developed and operated continuously for more than 1.5 years to evaluate continuous power generation while treating artificial wastewater containing glucose (10 mM) concurrently. A stable power density of 28 W/m3 was attained with an anode hydraulic retention time of 4.5 h and phosphate buffer as the cathode electrolyte. An overall dissolved organic carbon removal ratio was about 85%, and coulombic efficiency was about 46% in this MFC system. We also analyzed the microbial community structure of anode biofilms in each MFC. Since the environment in each MFC was different due to passing on the products to the next MFC in series, the microbial community structure was different accordingly. The anode biofilm in the first MFC consisted mainly of bacteria belonging to the Gammaproteobacteria, identified as Aeromonas sp., while the Firmicutes dominated the anode biofilms in the second and third MFCs that were mainly fed with acetate. Cyclic voltammetric results supported the presence of a redox compound(s) associated with the anode biofilm matrix, rather than mobile (dissolved) forms, which could be responsible for the electron transfer to the anode. Scanning electron microscopy revealed that the anode biofilms were comprised of morphologically different cells that were firmly attached on the anode surface and interconnected each other with anchor-like filamentous appendages, which might support the results of cyclic voltammetry. (orig.)

  4. Product Configuration Systems and Productivity

    DEFF Research Database (Denmark)

    Pedersen, Jørgen Lindgaard; Edwards, Kasper

    2004-01-01

    Twelve companies have been interviewed with the purpose to get information about technical, economic and organisational matters in respect of Product Configuration Systems (PCS).Combinations of qualitative interviews and quantitative scoring have been used in ranking expected and realized results...

  5. Circulating microbial products and acute phase proteins as markers of pathogenesis in lymphatic filarial disease.

    Directory of Open Access Journals (Sweden)

    R Anuradha

    Full Text Available Lymphatic filariasis can be associated with development of serious pathology in the form of lymphedema, hydrocele, and elephantiasis in a subset of infected patients. Dysregulated host inflammatory responses leading to systemic immune activation are thought to play a central role in filarial disease pathogenesis. We measured the plasma levels of microbial translocation markers, acute phase proteins, and inflammatory cytokines in individuals with chronic filarial pathology with (CP Ag+ or without (CP Ag- active infection; with clinically asymptomatic infections (INF; and in those without infection (endemic normal [EN]. Comparisons between the two actively infected groups (CP Ag+ compared to INF and those without active infection (CP Ag- compared to EN were used preliminarily to identify markers of pathogenesis. Thereafter, we tested for group effects among all the four groups using linear models on the log transformed responses of the markers. Our data suggest that circulating levels of microbial translocation products (lipopolysaccharide and LPS-binding protein, acute phase proteins (haptoglobin and serum amyloid protein-A, and inflammatory cytokines (IL-1β, IL-12, and TNF-α are associated with pathogenesis of disease in lymphatic filarial infection and implicate an important role for circulating microbial products and acute phase proteins.

  6. Impact of wheat / faba bean mixed cropping or rotation systems on soil microbial functionalities

    Directory of Open Access Journals (Sweden)

    Sanâa Wahbi

    2016-09-01

    Full Text Available Cropping systems based on carefully designed species mixtures reveal many potential advantages in terms of enhancing crop productivity, reducing pest and diseases and enhacing ecological serices. Associating cereals and legume production either through intercropping or rotations might be a relevant strategy of producing both type of culture, while benefiting from combined nitrogen fixed by the legume through its symbiotic association with nitrogen-fixing bacteria, and from a better use of P and water through mycorrhizal associations. These practices also participate to the diversification of agricultural productions, enabling to secure the regularity of income returns across the seasonal and climatic uncertainties. In this context, we designed a field experiment aiming to estimate the two years impact of these practices on wheat yield and on soil microbial activities as estimated through Substrate Induced Respiration (SIR method and mycorrhizal soil infectivity (MSI measurement. It is expected that understanding soil microbial functionalities in response to these agricultural practices might allows to target the best type of combination, in regard to crop productivity. We found that the tested cropping systems largely impacted soil microbial functionalities and mycorrhizal soil infectivity. Intercropping gave better results in terms of crop productivity than the rotation practice after 2 cropping seasons. Benefits resulting from intercrop should be highly linked with changes recorded on soil microbial functionalities.

  7. Pharmaceutical protein production by yeast: towards production of human blood proteins by microbial fermentation

    DEFF Research Database (Denmark)

    Martinez Ruiz, José Luis; Liu, Lifang; Petranovic, Dina

    2012-01-01

    Since the approval of recombinant insulin from Escherichia coli for its clinical use in the early 1980s, the amount of recombinant pharmaceutical proteins obtained by microbial fermentations has significantly increased. The recent advances in genomics together with high throughput analysis...... of recombinant therapeutics using yeast Saccharomyces cerevisiae as a model platform, and discusses the future potential of this platform for production of blood proteins and substitutes....

  8. Effect of different fertilizers on the microbial activity and productivity ...

    African Journals Online (AJOL)

    This study was conducted to evaluate the effect of the application of different rates of mineral nitrogen, well rotten farmyard manure and Klebsiella planticola SL09- based microbial biofertilizer (enteroplantin) on the count of soil microorganisms (total microbial count, counts of Azotobacter, oligonitrophilic bacteria, fungi and ...

  9. Microbial Indicators of Soil Quality under Different Land Use Systems in Subtropical Soils

    Science.gov (United States)

    Maharjan, M.

    2016-12-01

    Land-use change from native forest to intensive agricultural systems can negatively impact numerous soil parameters. Understanding the effects of forest ecosystem transformations on markers of long-term soil health is particularly important in rapidly developing regions such as Nepal, where unprecedented levels of agriculturally-driven deforestation have occurred in recent decades. However, the effects of widespread land use changes on soil quality in this region have yet to be properly characterized. Microbial indicators (soil microbial biomass, metabolic quotient and enzymes activities) are particularly suited to assessing the consequences of such ecosystem disturbances, as microbial communities are especially sensitive to environmental change. Thus, the aim of this study was to assess the effect of land use system; i.e. forest, organic and conventional farming, on soil quality in Chitwan, Nepal using markers of microbial community size and activity. Total organic C and N contents were higher in organic farming compared with conventional farming and forest, suggesting higher nutrient retention and soil preservation with organic farming practices compared to conventional. These differences in soil composition were reflected in the health of the soil microbial communities: Organic farm soil exhibited higher microbial biomass C, elevated β-glucosidase and chitinase activities, and a lower metabolic quotient relative to other soils, indicating a larger, more active, and less stressed microbial community, respectively. These results collectively demonstrate that application of organic fertilizers and organic residues positively influence nutrient availability, with subsequent improvements in soil quality and productivity. Furthermore, the sensitivity of microbial indicators to different management practices demonstrated in this study supports their use as effective markers of ecosystem disturbance in subtropical soils.

  10. 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

  11. Microbial community functional structure in response to antibiotics in pharmaceutical wastewater treatment systems.

    Science.gov (United States)

    Zhang, Yu; Xie, Jianping; Liu, Miaomiao; Tian, Zhe; He, Zhili; van Nostrand, Joy D; Ren, Liren; Zhou, Jizhong; Yang, Min

    2013-10-15

    It is widely demonstrated that antibiotics in the environment affect microbial community structure. However, direct evidence regarding the impacts of antibiotics on microbial functional structures in wastewater treatment systems is limited. Herein, a high-throughput functional gene array (GeoChip 3.0) in combination with quantitative PCR and clone libraries were used to evaluate the microbial functional structures in two biological wastewater treatment systems, which treat antibiotic production wastewater mainly containing oxytetracycline. Despite the bacteriostatic effects of antibiotics, the GeoChip detected almost all key functional gene categories, including carbon cycling, nitrogen cycling, etc., suggesting that these microbial communities were functionally diverse. Totally 749 carbon-degrading genes belonging to 40 groups (24 from bacteria and 16 from fungi) were detected. The abundance of several fungal carbon-degrading genes (e.g., glyoxal oxidase (glx), lignin peroxidase or ligninase (lip), manganese peroxidase (mnp), endochitinase, exoglucanase_genes) was significantly correlated with antibiotic concentrations (Mantel test; P functional genes have been enhanced by the presence of antibiotics. However, from the fact that the majority of carbon-degrading genes were derived from bacteria and diverse antibiotic resistance genes were detected in bacteria, it was assumed that many bacteria could survive in the environment by acquiring antibiotic resistance and may have maintained the position as a main player in nutrient removal. Variance partitioning analysis showed that antibiotics could explain 24.4% of variations in microbial functional structure of the treatment systems. This study provides insights into the impacts of antibiotics on microbial functional structure of a unique system receiving antibiotic production wastewater, and reveals the potential importance of the cooperation between fungi and bacteria with antibiotic resistance in maintaining the

  12. Effects of operational shocks on key microbial populations for biogas production in UASB (Upflow Anaerobic Sludge Blanket) reactors

    International Nuclear Information System (INIS)

    Couras, C.S.; Louros, V.L.; Grilo, A.M.; Leitão, J.H.; Capela, M.I.; Arroja, L.M.; Nadais, M.H.

    2014-01-01

    This work compares the overall performance and biogas production of continuous and intermittent UASB (Upflow Anaerobic Sludge Blanket) reactors treating dairy wastewater and subjected to fat, hydraulic and temperature shocks. The systems were monitored for methane production, effluent concentration, volatile fatty acids, and microbial populations of the Eubacteria, Archaea and Syntrophomonadaceae groups. This last microbial group has been reported in literature as being determinant for the degradation of fatty substrates present in the wastewater and subsequent biogas production. Results show that both continuous and intermittent systems supported the applied shocks. However, the intermittent systems exhibited better performance than the continuous systems in biogas production and physical-chemical parameters. Syntrophomonadaceae microbial group was present in the intermittent systems, but was not detected in the biomass from the continuous systems. Hydraulic and temperature shocks, but not the fat shock, caused severe losses in the relative abundance of the Syntrophomonadaceae group in intermittent systems, leading to undetectable levels during the temperature shock. The severity of the effects of the applied shocks on the key microbial group Syntrophomonadaceae, were classified as: fats < hydraulic < temperature. Results from a full-scale anaerobic reactor confirm the effect of intermittent operation on the presence of Syntrophomonadaceae and the effect on reactor performance. - Highlights: • We compared intermittent and continuous UASB reactors upon operational shocks. • Syntrophomonadaceae key microbial group for maximizing biogas was quantified by FISH. • Syntrophomonadaceae is present in intermittent but not in continuous UASB reactors. • Syntrophomonadaceae abundance increases with fat shock in intermittent UASB reactor. • Syntrophomonadaceae abundance decreases with hydraulic or temperature shock

  13. Microbial status and product labelling of 58 original tattoo inks.

    Science.gov (United States)

    Høgsberg, T; Saunte, D M; Frimodt-Møller, N; Serup, J

    2013-01-01

    European Council resolutions on tattoo ink introduce sterility and preservation of inks to protect customers. Inks used in Denmark are typically purchased over the internet from international suppliers and manufacturers from the US and the UK. In Denmark tattoo inks are regulated and labelled according to REACH as if they were plain chemicals. The objective of this study was to check the microbial product safety of unopened and opened tattoo ink stock bottles. Packaging, labelling, preservation, sterility and contamination with micro-organisms were studied. Physical inspection and culture of bacteria and fungi. Six of 58 unopened stock bottles (10%) were contaminated with bacteria and one of six samples (17%) of previously used stock bottles was contaminated. The bacterial species represented bacteria considered pathogenic in humans as well as non-pathogenic environmental bacteria. Yeast or moulds were detected in none of the samples. A total of 31% of the manufacturers informed only about the brand name. No information about content, sterility, risks or expiry date was indicated on the label. A total of 42% claimed sterility of their inks. A total of 54% labelled a maximum period of durability of typically 2-3 years. The physical sealing was leaking in 28% of the products. The European Council resolutions regarding safety of tattoo inks are not effective. Stock bottles of tattoo ink may contain bacteria pathogenic to humans and environmental bacteria, and packaging, labelling and preservation of inks are of inadequate quality. Claim of sterility can be erroneous. © 2011 The Authors. Journal of the European Academy of Dermatology and Venereology © 2011 European Academy of Dermatology and Venereology.

  14. A fermented meat model system for studies of microbial aroma formation

    DEFF Research Database (Denmark)

    Tjener, Karsten; Stahnke, Louise Heller; Andersen, L.

    2003-01-01

    A fermented meat model system was developed, by which microbial formation of volatiles could be examined The model was evaluated against dry, fermented sausages with respect to microbial growth, pH and volatile profiles. Fast and slowly acidified sausages and models were produced using the starter......H, microbial growth and volatile profiles was similar to sausage production. Based on these findings, the model system was considered valid for studies of aroma formation of meat cultures for fermented sausage....... for multivariate data analysis. Growth of lactic acid bacteria was comparable for model and sausages, whereas survival of S. xylosus was better in the model. Multivariate analysis of volatiles showed that differences between fast and slowly acidified samples were identical for model and sausage. For both sausage...

  15. In situ microbial systems for the enhancement of oil recovery

    International Nuclear Information System (INIS)

    Moses, V.

    1991-01-01

    Microbial Enhancement of Oil Recovery (MEOR) offers important new opportunities in the quest for increased oil production. It refers not to a single technique but rather to a collection of methodologies, analogous to parallel non-microbiological methods. MEOR has relevance for many type of production and reservoir problems detailed protocols: may be tailored specifically to a range of individual reservoir conditions. Microorganisms downhole can generate a wide variety of chemical products from inexpensive feed stocks: where these are more cost-effective than oil field chemicals injected from the surface, microbial methods may win widespread acceptance. MEOR methods must be defined precisely; in any particular reservoir procedure their proposed mechanism of action must be clearly understood and criteria established for evaluating their success. The most important applications for MEOR are 1) the production f insoluble or highly viscous polymer to control coning or to plug selectively high permeability thief zones and fractures, 2) the continuous generation of the active agents for polymer-and/or surfactant floods, 3) matrix acidisation and acid fracturing in carbonate rocks stimulate flows into production wells. All these approaches are currently actively been explored; several programmes for field-testing microbial EOR methods already exist, or are being readied, and rapid progress is likely within the next few years. (author)

  16. Microbial Consortium with High Cellulolytic Activity (MCHCA for enhanced biogas production.

    Directory of Open Access Journals (Sweden)

    Krzysztof ePoszytek

    2016-03-01

    Full Text Available The use of lignocellulosic biomass as a substrate in agricultural biogas plants is very popular and yields good results. However, the efficiency of anaerobic digestion, and thus biogas production, is not always satisfactory due to the slow or incomplete degradation (hydrolysis of plant matter. To enhance the solubilization of the lignocellulosic biomass various physical, chemical and biological pretreatment methods are used.The aim of this study was to select and characterize cellulose-degrading bacteria, and to construct a microbial consortium, dedicated for degradation of maize silage and enhancing biogas production from this substrate.Over one hundred strains of cellulose-degrading bacteria were isolated from: sewage sludge, hydrolyzer from an agricultural biogas plant, cattle slurry and manure. After physiological characterization of the isolates, sixteen strains (representatives of Bacillus, Providencia and Ochrobactrum genera were chosen for the construction of a Microbial Consortium with High Cellulolytic Activity, called MCHCA. The selected strains had a high endoglucanase activity (exceeding 0.21 IU/mL CMCase activity and a wide range of tolerance to various physical and chemical conditions. Lab-scale simulation of biogas production using the selected strains for degradation of maize silage was carried out in a two-bioreactor system, similar to those used in agricultural biogas plants.The obtained results showed that the constructed MCHCA consortium is capable of efficient hydrolysis of maize silage, and increases biogas production by even 38%, depending on the inoculum used for methane fermentation. The results in this work indicate that the mesophilic Microbial Consortium with High Cellulolytic Activity has a great potential for application on industrial scale in agricultural biogas plants.

  17. A fermented meat model system for studies of microbial aroma formation

    DEFF Research Database (Denmark)

    Tjener, Karsten; Stahnke, Louise Heller; Andersen, L.

    2003-01-01

    A fermented meat model system was developed, by which microbial formation of volatiles could be examined The model was evaluated against dry, fermented sausages with respect to microbial growth, pH and volatile profiles. Fast and slowly acidified sausages and models were produced using the starte......H, microbial growth and volatile profiles was similar to sausage production. Based on these findings, the model system was considered valid for studies of aroma formation of meat cultures for fermented sausage.......A fermented meat model system was developed, by which microbial formation of volatiles could be examined The model was evaluated against dry, fermented sausages with respect to microbial growth, pH and volatile profiles. Fast and slowly acidified sausages and models were produced using the starter...... cultures Pediococcus pentosaceus and Staphylococcus xylosus. Volatiles were collected and analysed by dynamic headspace sampling and GC MS. The analysis was primarily focused on volatiles arising from amino acid degradation and a total of 24 compounds, of which 19 were quantified, were used...

  18. Importance of microbial natural products and the need to revitalize their discovery.

    Science.gov (United States)

    Demain, Arnold L

    2014-02-01

    Microbes are the leading producers of useful natural products. Natural products from microbes and plants make excellent drugs. Significant portions of the microbial genomes are devoted to production of these useful secondary metabolites. A single microbe can make a number of secondary metabolites, as high as 50 compounds. The most useful products include antibiotics, anticancer agents, immunosuppressants, but products for many other applications, e.g., antivirals, anthelmintics, enzyme inhibitors, nutraceuticals, polymers, surfactants, bioherbicides, and vaccines have been commercialized. Unfortunately, due to the decrease in natural product discovery efforts, drug discovery has decreased in the past 20 years. The reasons include excessive costs for clinical trials, too short a window before the products become generics, difficulty in discovery of antibiotics against resistant organisms, and short treatment times by patients for products such as antibiotics. Despite these difficulties, technology to discover new drugs has advanced, e.g., combinatorial chemistry of natural product scaffolds, discoveries in biodiversity, genome mining, and systems biology. Of great help would be government extension of the time before products become generic.

  19. Effects of shearing on biogas production and microbial community structure during anaerobic digestion with recuperative thickening.

    Science.gov (United States)

    Yang, Shufan; Phan, Hop V; Bustamante, Heriberto; Guo, Wenshan; Ngo, Hao H; Nghiem, Long D

    2017-06-01

    Recuperative thickening can intensify anaerobic digestion to produce more biogas and potentially reduce biosolids odour. This study elucidates the effects of sludge shearing during the thickening process on the microbial community structure and its effect on biogas production. Medium shearing resulted in approximately 15% increase in biogas production. By contrast, excessive or high shearing led to a marked decrease in biogas production, possibly due to sludge disintegration and cell lysis. Microbial analysis using 16S rRNA gene amplicon sequencing showed that medium shearing increased the evenness and diversity of the microbial community in the anaerobic digester, which is consistent with the observed improved biogas production. By contrast, microbial diversity decreased under either excessive shearing or high shearing condition. In good agreement with the observed decrease in biogas production, the abundance of Bacteroidales and Syntrophobaterales (which are responsible for hydrolysis and acetogenesis) decreased due to high shearing during recuperative thickening. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  20. Effect of different fertilizers on the microbial activity and productivity ...

    African Journals Online (AJOL)

    Jane

    2011-07-18

    Jul 18, 2011 ... randomized block design in four replications at the experimental field of the Biotechnical Faculty,. Podgorica in ..... (plants, animals and humans) through the food chain. In general, the ... Microbial ecology of the rhizosphere.

  1. Microbial desalination cells for energy production and desalination

    KAUST Repository

    Kim, Younggy; Logan, Bruce E.

    2013-01-01

    Microbial desalination cells (MDCs) are a new, energy-sustainable method for using organic matter in wastewater as the energy source for desalination. The electric potential gradient created by exoelectrogenic bacteria desalinates water by driving

  2. Microbial Character Related Sulfur Cycle under Dynamic Environmental Factors Based on the Microbial Population Analysis in Sewerage System.

    Science.gov (United States)

    Dong, Qian; Shi, Hanchang; Liu, Yanchen

    2017-01-01

    The undesired sulfur cycle derived by microbial population can ultimately causes the serious problems of sewerage systems. However, the microbial community characters under dynamic environment factors in actual sewerage system is still not enough. This current study aimed to character the distributions and compositions of microbial communities that participate in the sulfur cycle under the dynamic environmental conditions in a local sewerage system. To accomplish this, microbial community compositions were assessed using 454 high-throughput sequencing (16S rDNA) combined with dsrB gene-based denaturing gradient gel electrophoresis. The results indicated that a higher diversity of microbial species was present at locations in sewers with high concentrations of H 2 S. Actinobacteria and Proteobacteria were dominant in the sewerage system, while Actinobacteria alone were dominant in regions with high concentrations of H 2 S. Specifically, the unique operational taxonomic units could aid to characterize the distinct microbial communities within a sewerage manhole. The proportion of sulfate-reducing bacteria, each sulfur-oxidizing bacteria (SOB) were strongly correlated with the liquid parameters (DO, ORP, COD, Sulfide, NH 3 -N), while the Mycobacterium and Acidophilic SOB (M&A) was strongly correlated with gaseous factors within the sewer, such as H 2 S, CH 4 , and CO. Identifying the distributions and proportions of critical microbial communities within sewerage systems could provide insights into how the microbial sulfur cycle is affected by the dynamic environmental conditions that exist in sewers and might be useful for explaining the potential sewerage problems.

  3. Direct fed microbial supplementation repartitions host energy to the immune system.

    Science.gov (United States)

    Qiu, R; Croom, J; Ali, R A; Ballou, A L; Smith, C D; Ashwell, C M; Hassan, H M; Chiang, C-C; Koci, M D

    2012-08-01

    Direct fed microbials and probiotics are used to promote health in livestock and poultry; however, their mechanism of action is still poorly understood. We previously reported that direct fed microbial supplementation in young broilers reduced ileal respiration without changing whole-body energy expenditure. The current studies were conducted to further investigate the effects of a direct fed microbial on energy metabolism in different tissues of broilers. One hundred ninety-two 1-d-old broiler chicks (16 chicks/pen) were randomly assigned to 2 dietary groups: standard control starter diet (CSD) and CSD plus direct fed microbial (DFMD; 0.3%) with 6 pens/treatment. Body weight, feed consumption, whole-body energy expenditure, organ mass, tissue respiration rates, and peripheral blood mononuclear cell (PBMC) ATP concentrations were measured to estimate changes in energy metabolism. No differences in whole body energy expenditure or BW gain were observed; however, decreased ileal O(2) respiration (P energy consumption by PBMC corresponded with an altered immune response, broilers were immunized with sheep red blood cells (SRBC) and assayed for differences in their humoral response. The DFMD-fed broilers had a faster rate of antigen specific IgG production (P direct fed microbial used in this study resulted in energy re-partitioning to the immune system and an increase in antibody production independent of changes in whole body metabolism or growth performance.

  4. Microbial desalination cells for energy production and desalination

    KAUST Repository

    Kim, Younggy

    2013-01-01

    Microbial desalination cells (MDCs) are a new, energy-sustainable method for using organic matter in wastewater as the energy source for desalination. The electric potential gradient created by exoelectrogenic bacteria desalinates water by driving ion transport through a series of ion-exchange membranes (IEMs). The specific MDC architecture and current conditions substantially affect the amount of wastewater needed to desalinate water. Other baseline conditions have varied among studies making comparisons of the effectiveness of different designs problematic. The extent of desalination is affected by water transport through IEMs by both osmosis and electroosmosis. Various methods have been used, such as electrolyte recirculation, to avoid low pH that can inhibit exoelectrogenic activity. The highest current density in an MDC to date is 8.4A/m2, which is lower than that produced in other bioelectrochemical systems. This implies that there is a room for substantial improvement in desalination rates and overall performance. We review here the state of the art in MDC design and performance, safety issues related to the use of MDCs with wastewater, and areas that need to be examined to achieve practical application of this new technology. © 2012 Elsevier B.V.

  5. Glucosidase: microbial production and effect on enzymatic hydrolysis of cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Sternberg, D

    1977-01-01

    The enzymic conversion of cellulose is catalyzed by a multiple enzyme system. The Trichoderma enzyme system has insufficient ..beta..-glucosidase (EC 3.2.1.21) activity for the practical saccharification of cellulose. Aspergillus niger and A. phoenicis were superior producers of ..beta.. glucosidase and a method for production of this enzyme in liquid culture is presented. When Trichoderma cellulase preparations are supplemented with ..beta.. glucosidase from Aspergullus during practical saccharifications glucose is the predominant product and the rate of saccharification is significantly increased. The stimulatory effect of ..beta.. glucosidase appears to be due to the removal of inhibitory levels of cellobiose.

  6. Pesticide Product Label System

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Pesticide Product Label System (PPLS) provides a collection of pesticide product labels (Adobe PDF format) that have been approved by EPA under Section 3 of the...

  7. Characterization of microbial communities and fungal metabolites on field grown strawberries from organic and conventional production

    DEFF Research Database (Denmark)

    Jensen, Birgit; Knudsen, Inge M. B.; Andersen, Birgitte

    2013-01-01

    The background levels of culturable indigenous microbial communities (microbiotas) on strawberries were examined in a field survey with four conventional and four organic growers with different production practise and geographic distribution. The microbiota on apparently healthy strawberries...... was complex including potential plant pathogens, opportunistic human pathogens, plant disease biocontrol agents and mycotoxin producers. The latter group was dominated by Penicillium spp. and Aspergillus niger was also isolated. As expected, bacteria were the most abundant and diverse group of the strawberry...... microbiota followed by yeasts and filamentous fungi. No obvious correlation between grower practice and the strawberry microbiota was observed. Differences between microbiotas on strawberries from conventional systems with up to 10 fungicide spray treatments and organic production systems were insignificant...

  8. Influence of phosphorus precipitation on permeability and soluble microbial product concentration in a membrane bioreactor

    Czech Academy of Sciences Publication Activity Database

    Gómez, M.; Dvořák, L.; Růžičková, I.; Wanner, J.; Holba, Marek; Sýkorová, E.

    2013-01-01

    Roč. 129, Feb 2013 (2013), s. 164-169 ISSN 0960-8524 Institutional support: RVO:67985939 Keywords : membrane bioreactor * coagulant adition * soluble microbial products Subject RIV: EF - Botanics Impact factor: 5.039, year: 2013

  9. Microbial Electrolysis Cells for High Yield Hydrogen Gas Production from Organic Matter

    KAUST Repository

    Logan, Bruce E.; Call, Douglas; Cheng, Shaoan; Hamelers, Hubertus V. M.; Sleutels, Tom H. J. A.; Jeremiasse, Adriaan W.; Rozendal, René A.

    2008-01-01

    production rates. MECs used to make hydrogen gas are similar in design to microbial fuel cells (MFCs) that produce electricity, but there are important differences in architecture and analytical methods used to evaluate performance. We review here

  10. Microbial electrolysis desalination and chemical-production cell for CO2 sequestration

    KAUST Repository

    Zhu, Xiuping; Logan, Bruce E.

    2014-01-01

    Mineral carbonation can be used for CO2 sequestration, but the reaction rate is slow. In order to accelerate mineral carbonation, acid generated in a microbial electrolysis desalination and chemical-production cell (MEDCC) was examined to dissolve

  11. Application of microbial photosynthesis to energy production and CO2 fixation

    International Nuclear Information System (INIS)

    Asada, Y.; Miyake, J.

    1994-01-01

    This paper presents different applications of microbial photosynthesis for energy production and carbon dioxide fixation. The authors discuss about energetic aspects of photosynthesis and features of biological way for solar energy conversion. (TEC). 4 figs., 12 refs

  12. Microbial production host selection for converting second-generation feedstocks into bioproducts

    NARCIS (Netherlands)

    Rumbold, K.; Buijsen, H.J.J. van; Overkamp, K.M.; Groenestijn, J.W. van; Punt, P.J.; Werf, M.J.V.D.

    2009-01-01

    Increasingly lignocellulosic biomass hydrolysates are used as the feedstock for industrial fermentations. These biomass hydrolysates are complex mixtures of different fermentable sugars, but also inhibitors and salts that affect the performance of the microbial production host. The performance of

  13. Patterned ion exchange membranes for improved power production in microbial reverse-electrodialysis cells

    KAUST Repository

    Liu, Jia; Geise, Geoffrey M.; Luo, Xi; Hou, Huijie; Zhang, Fang; Feng, Yujie; Hickner, Michael A.; Logan, Bruce E.

    2014-01-01

    Power production in microbial reverse-electrodialysis cells (MRCs) can be limited by the internal resistance of the reverse electrodialysis stack. Typical MRC stacks use non-conductive spacers that block ion transport by the so-called spacer shadow

  14. [Fermentation production of microbial catalase and its application in textile industry].

    Science.gov (United States)

    Zhang, Dongxu; Du, Guocheng; Chen, Jian

    2010-11-01

    Microbial catalase is an important industrial enzyme that catalyzes the decomposition of hydrogen peroxide to water and oxygen. This enzyme has great potential of application in food, textile and pharmaceutical industries. The production of microbial catalase has been significantly improved thanks to advances in bioprocess engineering and genetic engineering. In this paper, we review the progresses in fermentation production of microbial catalase and its application in textile industry. Among these progresses, we will highlight strain isolation, substrate and environment optimization, enzyme induction, construction of engineering strains and application process optimization. Meanwhile, we also address future research trends for microbial catalase production and its application in textile industry. Molecular modification (site-directed mutagenesis and directed revolution) will endue catalase with high pH and temperature stabilities. Improvement of catalase production, based on the understanding of induction mechanism and the process control of recombinant stain fermentation, will further accelerate the application of catalase in textile industry.

  15. Design of a microbial fuel cell and its transition to microbial electrolytic cell for hydrogen production by electrohydrogenesis.

    Science.gov (United States)

    Gupta, Pratima; Parkhey, Piyush; Joshi, Komal; Mahilkar, Anjali

    2013-10-01

    Anaerobic bacteria were isolated from industrial wastewater and soil samples and tested for exoelectrogenic activity by current production in double chambered microbial fuel cell (MFC), which was further transitioned into a single chambered microbial electrolytic cell to test hydrogen production by electrohydrogenesis. Of all the cultures, the isolate from industrial water sample showed the maximum values for current = 0.161 mA, current density = 108.57 mA/m2 and power density = 48.85 mW/m2 with graphite electrode. Maximum voltage across the cell, however, was reported by the isolate from sewage water sample (506 mv) with copper as electrode. Tap water with KMnO4 was the best cathodic electrolyte as the highest values for all the measured MFC parameters were reported with it. Once the exoelectrogenic activity of the isolates was confirmed by current production, these were tested for hydrogen production in a single chambered microbial electrolytic cell (MEC) modified from the MFC. Hydrogen production was reported positive from co-culture of isolates of both the water samples and co-culture of one soil and one water sample. The maximum rate and yield of hydrogen production was 0.18 m3H2/m3/d and 3.2 mol H2/mol glucose respectively with total hydrogen production of 42.4 mL and energy recovery of 57.4%. Cumulative hydrogen production for a five day cycle of MEC operation was 0.16 m3H2/m3/d.

  16. Reprint of Design of synthetic microbial communities for biotechnological production processes.

    Science.gov (United States)

    Jagmann, Nina; Philipp, Bodo

    2014-12-20

    In their natural habitats microorganisms live in multi-species communities, in which the community members exhibit complex metabolic interactions. In contrast, biotechnological production processes catalyzed by microorganisms are usually carried out with single strains in pure cultures. A number of production processes, however, may be more efficiently catalyzed by the concerted action of microbial communities. This review will give an overview of organismic interactions between microbial cells and of biotechnological applications of microbial communities. It focuses on synthetic microbial communities that consist of microorganisms that have been genetically engineered. Design principles for such synthetic communities will be exemplified based on plausible scenarios for biotechnological production processes. These design principles comprise interspecific metabolic interactions via cross-feeding, regulation by interspecific signaling processes via metabolites and autoinducing signal molecules, and spatial structuring of synthetic microbial communities. In particular, the implementation of metabolic interdependencies, of positive feedback regulation and of inducible cell aggregation and biofilm formation will be outlined. Synthetic microbial communities constitute a viable extension of the biotechnological application of metabolically engineered single strains and enlarge the scope of microbial production processes. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Design, engineering, and construction of photosynthetic microbial cell factories for renewable solar fuel production.

    Science.gov (United States)

    Lindblad, Peter; Lindberg, Pia; Oliveira, Paulo; Stensjö, Karin; Heidorn, Thorsten

    2012-01-01

    There is an urgent need to develop sustainable solutions to convert solar energy into energy carriers used in the society. In addition to solar cells generating electricity, there are several options to generate solar fuels. This paper outlines and discusses the design and engineering of photosynthetic microbial systems for the generation of renewable solar fuels, with a focus on cyanobacteria. Cyanobacteria are prokaryotic microorganisms with the same type of photosynthesis as higher plants. Native and engineered cyanobacteria have been used by us and others as model systems to examine, demonstrate, and develop photobiological H(2) production. More recently, the production of carbon-containing solar fuels like ethanol, butanol, and isoprene have been demonstrated. We are using a synthetic biology approach to develop efficient photosynthetic microbial cell factories for direct generation of biofuels from solar energy. Present progress and advances in the design, engineering, and construction of such cyanobacterial cells for the generation of a portfolio of solar fuels, e.g., hydrogen, alcohols, and isoprene, are presented and discussed. Possibilities and challenges when introducing and using synthetic biology are highlighted.

  18. Design, Engineering, and Construction of Photosynthetic Microbial Cell Factories for Renewable Solar Fuel Production

    Energy Technology Data Exchange (ETDEWEB)

    Lindblad, Peter; Lindberg, Pia; Stensjoe, Karin (Photochemistry and Molecular Science, Dept. of Chemistry-Aangstroem Laboratory, Uppsala Univ., Uppsala (Sweden)), E-mail: Peter.Lindblad@kemi.uu.se; Oliveira, Paulo (Instituto de Biologia Molecular e Celular, Porto (Portugal)); Heidorn, Thorsten (Bioforsk-Norwegian Inst. for Agricultural and Environmental Research, Aas Oslo, (Norway))

    2012-03-15

    There is an urgent need to develop sustainable solutions to convert solar energy into energy carriers used in the society. In addition to solar cells generating electricity, there are several options to generate solar fuels. This paper outlines and discusses the design and engineering of photosynthetic microbial systems for the generation of renewable solar fuels, with a focus on cyanobacteria. Cyanobacteria are prokaryotic microorganisms with the same type of photosynthesis as higher plants. Native and engineered cyanobacteria have been used by us and others as model systems to examine, demonstrate, and develop photobiological H{sub 2} production. More recently, the production of carbon-containing solar fuels like ethanol, butanol, and isoprene have been demonstrated. We are using a synthetic biology approach to develop efficient photosynthetic microbial cell factories for direct generation of biofuels from solar energy. Present progress and advances in the design, engineering, and construction of such cyanobacterial cells for the generation of a portfolio of solar fuels, e.g., hydrogen, alcohols, and isoprene, are presented and discussed. Possibilities and challenges when introducing and using synthetic biology are highlighted

  19. Effect of Pulp mill sludge on soil characteristics, microbial diversity and vegetal production of Lollium perene

    Energy Technology Data Exchange (ETDEWEB)

    Gallardo, F.; Cea, M.; Diez, M. C.

    2009-07-01

    The Chemical properties of the sludge (High organic matter content, pH, buffer capacity, nitrogen and phosphorous level, and low concentration of trace heavy metals and organic pollutants) suggest that this material may represent a valuable resource as soil amendment, improving soil characteristics, microbial diversity and vegetal production of mill sludge addition to volcanic soil (Andisol) on soil characteristics, microbial diversity and vegetal production of Lollium perenne, in field assays. (Author)

  20. Organic acid production from starchy waste by rumen derived microbial communities

    OpenAIRE

    Ayudthaya, S. P. N.; Van De Weijer, Antonius H. P.; Van Gelder, Antonie H.; Stams, Alfons Johannes Maria; De Vos, Willem M.; Plugge, Caroline M.

    2017-01-01

    Microbiology Centennial Symposium 2017 - Exploring Microbes for the Quality of Life (Book of Abstracts) Converting organic waste to energy carriers and valuable products such as organic acids (OA) using microbial fermentation is one of the sustainable options of renewable energy. Substrate and inoculum are important factors in optimizing the fermentation. In this study, we investigated organic acid production and microbial composition shift during the fermentation of starchy (p...

  1. Trade-offs between microbiome diversity and productivity in a stratified microbial mat

    Energy Technology Data Exchange (ETDEWEB)

    Bernstein, Hans C.; Brislawn, Colin; Renslow, Ryan S.; Dana, Karl; Morton, Beau; Lindemann, Stephen R.; Song, Hyun-Seob; Atci, Erhan; Beyenal, Haluk; Fredrickson, James K.; Jansson, Janet K.; Moran, James J.

    2016-11-01

    Productivity is a major determinant of ecosystem diversity. Microbial ecosystems are the most diverse on the planet yet very few relationships between diversity and productivity have been reported as compared to macro-ecological studies. Here we evaluated the spatial relationships of productivity and microbiome diversity in a laboratory-cultivated photosynthetic mat. The goal was to determine how spatial diversification of microorganisms drives localized carbon and energy acquisition rates. We measured sub-millimeter depth profiles of net primary-productivity and gross oxygenic photosynthesis in the context of the localized microenvironment and community structure and observed negative correlations between species richness and productivity within the energy-replete, photic zone. Variations between localized community structures were associated with distinct taxa as well as environmental profiles describing a continuum of biological niches. Spatial regions corresponding to high primary productivity and photosynthesis rates had relatively low species richness and high evenness. Hence, this system exhibited negative species-productivity and species–energy relationships. These negative relationships may be indicative of photosynthetically-driven, light-controlled mat ecosystems that are able to be the most productive with a relatively smaller, even distributions of species that specialize within the highly-oxic, photic zones.

  2. Microbial platform technology for recombinant antibody fragment production: A review.

    Science.gov (United States)

    Gupta, Sanjeev Kumar; Shukla, Pratyoosh

    2017-02-01

    Recombinant antibody fragments are being used for the last few years as an important therapeutic protein to cure various critical and life threatening human diseases. Several expression platforms now days employed for the production of these recombinant fragments, out of which bacterial system has emerged a promising host for higher expression. Since, a small antibody fragment unlike full antibody does not require human-like post-translational modification therefore it is potentially expressed in prokaryotic production system. Recently, small antibody fragments such as scFvs (single-chain variable fragments) and Fabs (antibody fragments) which does not require glycosylation are successfully produced in bacteria and have commercially launched for therapeutic use as these fragments shows better tissue penetration and less immunogenic to human body compared to full-size antibody. Recently developed Wacker's ESETEC secretion technology is an efficient technology for the expression and secretion of the antibody fragment (Fab) exceeded up to 4.0 g/L while scFv up to 3.5 g/L into the fermentation broth. The Pfenex system and pOP prokaryotic expression vector are another platform used for the considerably good amount of antibody fragment production successfully. In this review, we summarize the recent progress on various expression platforms and cloning approaches for the production of different forms of antibody fragments in E. coli.

  3. COMBINED MICROBIAL SURFACTANT-POLYMER SYSTEM FOR IMPROVED OIL MOBILITY AND CONFORMANCE CONTROL

    Energy Technology Data Exchange (ETDEWEB)

    Jorge Gabitto; Maria Barrufet

    2004-08-01

    Many domestic oil fields are facing abandonment even though they still contain two-thirds of their original oil. A significant number of these fields can yield additional oil using advanced oil recovery (AOR) technologies. To maintain domestic oil production at current levels, AOR technologies are needed that are affordable and can be implemented by independent oil producers of the future. Microbial enhanced oil recovery (MEOR) technologies have become established as cost-effective solutions for declining oil production. MEOR technologies are affordable for independent producers operating stripper wells and can be used to extend the life of marginal fields. The demonstrated versatility of microorganisms can be used to design advanced microbial systems to treat multiple production problems in complex, heterogeneous reservoirs. The proposed research presents the concept of a combined microbial surfactant-polymer system for advanced oil recovery. The surfactant-polymer system utilizes bacteria that are capable of both biosurfactant production and metabolically-controlled biopolymer production. This novel technology combines complementary mechanisms to extend the life of marginal fields and is applicable to a large number of domestic reservoirs. The research project described in this report is performed jointly by, Bio-Engineering Inc., a woman owned small business, Texas A&M University and Prairie View A&M University, a Historically Black College and University. This report describes the results of our laboratory work to grow microbial cultures and the work done on recovery experiments on core rocks. We have selected two bacterial strains capable of producing both surfactant and polymers. We have conducted laboratory experiments to determine under what conditions surfactants and polymers can be produced from one single strain. We have conduct recovery experiments to determine the performance of these strains under different conditions. Our results do not show a

  4. Differences in microbial community composition between injection and production water samples of water flooding petroleum reservoirs

    Directory of Open Access Journals (Sweden)

    P. K. Gao

    2015-06-01

    Full Text Available Microbial communities in injected water are expected to have significant influence on those of reservoir strata in long-term water flooding petroleum reservoirs. To investigate the similarities and differences in microbial communities in injected water and reservoir strata, high-throughput sequencing of microbial partial 16S rRNA of the water samples collected from the wellhead and downhole of injection wells, and from production wells in a homogeneous sandstone reservoir and a heterogeneous conglomerate reservoir were performed. The results indicate that a small number of microbial populations are shared between the water samples from the injection and production wells in the sandstone reservoir, whereas a large number of microbial populations are shared in the conglomerate reservoir. The bacterial and archaeal communities in the reservoir strata have high concentrations, which are similar to those in the injected water. However, microbial population abundance exhibited large differences between the water samples from the injection and production wells. The number of shared populations reflects the influence of microbial communities in injected water on those in reservoir strata to some extent, and show strong association with the unique variation of reservoir environments.

  5. Reductive dehalogenation in microbial and electrolytic model systems

    International Nuclear Information System (INIS)

    Criddle, C.S.

    1990-01-01

    This research addresses the principles or reductive dehalogenation, with a focus on microbial processes. Carbon tetrachloride (CT) was selected as a model compound for intensive investigation. Three different experimental systems were studied: pure cultures of Escherichia coli k-12, pure cultures of a denitrifying Pseudomonad isolated from aquifer solids (Pseudomonas sp. strain KC), and an electrolysis cell. The product distributions were consistent with the hypothesis that CT undergoes a rate-limiting reduction to radical species which rapidly react with constituents of the surrounding milieu. In cultures of E. coli k-12, use of oxygen and nitrate as terminal electron acceptors generally prevented CT transformation. At low oxygen levels (∼ 1%), however, transformation of 14 C-CT to 14 C-CO 2 and attachment to cell material did occur in accord with reports of CT fate in mammalian cell cultures. Under fumarate-respiring conditions, 14 C-CT was recovered as 14 C-C 2 , chloroform (CF), and in a non-volatile fraction. In contrast, fermenting conditions resulted in more CF, more cell-bound 14 C, and almost no 14 C-CO 2 . Rates were faster under fermenting conditions than under fumarate-respiring conditions. Rates also decreased over time suggesting the gradual exhaustion of transformation activity. This loss was modeled with a simple exponential decay term. Pseudomonas sp. strain KC converted 14 C-CT to 14 C-CO 2 under denitrifying conditions, without CF production. Strain KC was the only organism of several denitrifiers that transformed CT. Induction of CT transformation by strain KC depended upon the presence of trace metals. Addition of ferrous iron and cobalt inhibited CT transformation. For strain KC, CT transformation is apparently linked to its mechanism for trace metal acquisition

  6. Systems strategies for developing industrial microbial strains

    DEFF Research Database (Denmark)

    Lee, Sang Yup; Kim, Hyun Uk

    2015-01-01

    Industrial strain development requires system-wide engineering and optimization of cellular metabolism while considering industrially relevant fermentation and recovery processes. It can be conceptualized as several strategies, which may be implemented in an iterative fashion and in different...

  7. Modeling how soluble microbial products (SMP) support heterotrophic bacteria in autotroph-based biofilms

    DEFF Research Database (Denmark)

    Merkey, Brian; Rittmann, Bruce E.; Chopp, David L.

    2009-01-01

    . In this paper, we develop and use a mathematical model to describe a model biofilm system that includes autotrophic and heterotrophic bacteria and the key products produced by the bacteria. The model combines the methods of earlier multi-species models with a multi-component biofilm model in order to explore...... the interaction between species via exchange of soluble microbial products (SMP). We show that multiple parameter sets are able to describe the findings of experimental studies, and that heterotrophs growing on autotrophically produced SMP may pursue either r- or K-strategies to sustain themselves when SMP...... is their only substrate. We also show that heterotrophs can colonize some distance from the autotrophs and still be sustained by autotrophically produced SMP. This work defines the feasible range of parameters for utilization of SMP by heterotrophs and the nature of the interactions between autotrophs...

  8. Evaluation of microbial content of some soybean milk products ...

    African Journals Online (AJOL)

    Evaluating the microbiological content of soybean milk, highly consumed by the public is the aim of this research work. Ten samples of soybean milk, locally prepared by different manufacturers were used for the study. The microbial load and identity of the microorganisms present were determined using standard ...

  9. Microbial and heavy metal contamination of pineapple products ...

    African Journals Online (AJOL)

    SAM

    3Department of Social Sciences, University of Rwanda, P.O. Box 117 Butare, ... pineapple processing Enterprises (SMEs) over a storage duration of 12 months. .... The results were measured against ... analyzed for microbial contamination using International Organization ... All culture media used were manufactured by.

  10. Hydrogen production profiles using furans in microbial electrolysis cells.

    Science.gov (United States)

    Catal, Tunc; Gover, Tansu; Yaman, Bugra; Droguetti, Jessica; Yilancioglu, Kaan

    2017-06-01

    Microbial electrochemical cells including microbial fuel cells (MFCs) and microbial electrolysis cells (MECs) are novel biotechnological tools that can convert organic substances in wastewater or biomass into electricity or hydrogen. Electroactive microbial biofilms used in this technology have ability to transfer electrons from organic compounds to anodes. Evaluation of biofilm formation on anode is crucial for enhancing our understanding of hydrogen generation in terms of substrate utilization by microorganisms. In this study, furfural and hydroxymethylfurfural (HMF) were analyzed for hydrogen generation using single chamber membrane-free MECs (17 mL), and anode biofilms were also examined. MECs were inoculated with mixed bacterial culture enriched using chloroethane sulphonate. Hydrogen was succesfully produced in the presence of HMF, but not furfural. MECs generated similar current densities (5.9 and 6 mA/cm 2 furfural and HMF, respectively). Biofilm samples obtained on the 24th and 40th day of cultivation using aromatic compounds were evaluated by using epi-fluorescent microscope. Our results show a correlation between biofilm density and hydrogen generation in single chamber MECs.

  11. Diversified cropping systems support greater microbial cycling and retention of carbon and nitrogen

    Energy Technology Data Exchange (ETDEWEB)

    King, Alison E.; Hofmockel, Kirsten S.

    2017-03-01

    Diversifying biologically simple cropping systems often entails altering other management practices, such as tillage regime or nitrogen (N) source. We hypothesized that the interaction of crop rotation, N source, and tillage in diversified cropping systems would promote microbially-mediated soil C and N cycling while attenuating inorganic N pools. We studied a cropping systems trial in its 10th year in Iowa, USA, which tested a 2-yr cropping system of corn (Zea mays L.)/soybean [Glycine max (L.) Merr.] managed with conventional fertilizer N inputs and conservation tillage, a 3-yr cropping system of corn/soybean/small grain + red clover (Trifolium pratense L.), and a 4-yr cropping system of corn/soybean/small grain + alfalfa (Medicago sativa L.)/alfalfa. Three year and 4-yr cropping systems were managed with composted manure, reduced N fertilizer inputs, and periodic moldboard ploughing. We assayed soil microbial biomass carbon (MBC) and N (MBN), soil extractable NH4 and NO3, gross proteolytic activity of native soil, and potential activity of six hydrolytic enzymes eight times during the growing season. At the 0-20cm depth, native protease activity in the 4-yr cropping system was greater than in the 2-yr cropping system by a factor of 7.9, whereas dissolved inorganic N pools did not differ between cropping systems (P = 0.292). At the 0-20cm depth, MBC and MBN the 4-yr cropping system exceeded those in the 2-yr cropping system by factors of 1.51 and 1.57. Our findings suggest that diversified crop cropping systems, even when periodically moldboard ploughed, support higher levels of microbial biomass, greater production of bioavailable N from SOM, and a deeper microbially active layer than less diverse cropping systems.

  12. Microbial electron transport and energy conservation – the foundation for optimizing bioelectrochemical systems

    Science.gov (United States)

    Kracke, Frauke; Vassilev, Igor; Krömer, Jens O.

    2015-01-01

    Microbial electrochemical techniques describe a variety of emerging technologies that use electrode–bacteria interactions for biotechnology applications including the production of electricity, waste and wastewater treatment, bioremediation and the production of valuable products. Central in each application is the ability of the microbial catalyst to interact with external electron acceptors and/or donors and its metabolic properties that enable the combination of electron transport and carbon metabolism. And here also lies the key challenge. A wide range of microbes has been discovered to be able to exchange electrons with solid surfaces or mediators but only a few have been studied in depth. Especially electron transfer mechanisms from cathodes towards the microbial organism are poorly understood but are essential for many applications such as microbial electrosynthesis. We analyze the different electron transport chains that nature offers for organisms such as metal respiring bacteria and acetogens, but also standard biotechnological organisms currently used in bio-production. Special focus lies on the essential connection of redox and energy metabolism, which is often ignored when studying bioelectrochemical systems. The possibility of extracellular electron exchange at different points in each organism is discussed regarding required redox potentials and effect on cellular redox and energy levels. Key compounds such as electron carriers (e.g., cytochromes, ferredoxin, quinones, flavins) are identified and analyzed regarding their possible role in electrode–microbe interactions. This work summarizes our current knowledge on electron transport processes and uses a theoretical approach to predict the impact of different modes of transfer on the energy metabolism. As such it adds an important piece of fundamental understanding of microbial electron transport possibilities to the research community and will help to optimize and advance bioelectrochemical

  13. Conversion of Crude Oil to Methane by a Microbial Consortium Enriched From Oil Reservoir Production Waters

    Directory of Open Access Journals (Sweden)

    Carolina eBerdugo-Clavijo

    2014-05-01

    Full Text Available The methanogenic biodegradation of crude oil is an important process occurring in petroleum reservoirs and other oil-containing environments such as contaminated aquifers. In this process, syntrophic bacteria degrade hydrocarbon substrates to products such as acetate, and/or H2 and CO2 that are then used by methanogens to produce methane in a thermodynamically dependent manner. We enriched a methanogenic crude oil-degrading consortium from production waters sampled from a low temperature heavy oil reservoir. Alkylsuccinates indicative of fumarate addition to C5 and C6 n-alkanes were identified in the culture (above levels found in controls, corresponding to the detection of an alkyl succinate synthase gene (assA in the culture. In addition, the enrichment culture was tested for its ability to produce methane from residual oil in a sandstone-packed column system simulating a mature field. Methane production rates of up 5.8 μmol CH4/g of oil/day were measured in the column system. Amounts of produced methane were in relatively good agreement with hydrocarbon loss showing depletion of more than 50% of saturate and aromatic hydrocarbons. Microbial community analysis revealed that the enrichment culture was dominated by members of the genus Smithella, Methanosaeta, and Methanoculleus. However, a shift in microbial community occurred following incubation of the enrichment in the sandstone columns. Here, Methanobacterium sp. were most abundant, as were bacterial members of the genus Pseudomonas and other known biofilm forming organisms. Our findings show that microorganisms enriched from petroleum reservoir waters can bioconvert crude oil components to methane both planktonically and in sandstone-packed columns as test systems. Further, the results suggest that different organisms may contribute to oil biodegradation within different phases (e.g., planktonic versus sessile within a subsurface crude oil reservoir.

  14. IMG: the integrated microbial genomes database and comparative analysis system

    Science.gov (United States)

    Markowitz, Victor M.; Chen, I-Min A.; Palaniappan, Krishna; Chu, Ken; Szeto, Ernest; Grechkin, Yuri; Ratner, Anna; Jacob, Biju; Huang, Jinghua; Williams, Peter; Huntemann, Marcel; Anderson, Iain; Mavromatis, Konstantinos; Ivanova, Natalia N.; Kyrpides, Nikos C.

    2012-01-01

    The Integrated Microbial Genomes (IMG) system serves as a community resource for comparative analysis of publicly available genomes in a comprehensive integrated context. IMG integrates publicly available draft and complete genomes from all three domains of life with a large number of plasmids and viruses. IMG provides tools and viewers for analyzing and reviewing the annotations of genes and genomes in a comparative context. IMG's data content and analytical capabilities have been continuously extended through regular updates since its first release in March 2005. IMG is available at http://img.jgi.doe.gov. Companion IMG systems provide support for expert review of genome annotations (IMG/ER: http://img.jgi.doe.gov/er), teaching courses and training in microbial genome analysis (IMG/EDU: http://img.jgi.doe.gov/edu) and analysis of genomes related to the Human Microbiome Project (IMG/HMP: http://www.hmpdacc-resources.org/img_hmp). PMID:22194640

  15. Lactose Bioelectricity on a Microbial Fuel Cell System Parallel Circuit Using Lactobacillus Bulgaricus

    OpenAIRE

    Putra, Adi; Nuryanto, Rahmad; Suyati, Linda

    2014-01-01

    Electrical energy needs in Indonesia is estimated to continue growing by 4.6% per year, and if there is nothing to be done to increase the production of electric energy, this figure will increase threefold by 2030. Microbial Fuel Cells (MFC) is one way to produce alternative electric energy by utilizing organic material as a substrate for bacterial metabolic activity that generate electricity. The aim of this study is to examine lactose bioelectricity in a parallel circuit MFC system using La...

  16. A model for improving microbial biofuel production using a synthetic feedback loop

    Energy Technology Data Exchange (ETDEWEB)

    Dunlop, Mary; Keasling, Jay; Mukhopadhyay, Aindrila

    2011-07-14

    Cells use feedback to implement a diverse range of regulatory functions. Building synthetic feedback control systems may yield insight into the roles that feedback can play in regulation since it can be introduced independently of native regulation, and alternative control architectures can be compared. We propose a model for microbial biofuel production where a synthetic control system is used to increase cell viability and biofuel yields. Although microbes can be engineered to produce biofuels, the fuels are often toxic to cell growth, creating a negative feedback loop that limits biofuel production. These toxic effects may be mitigated by expressing efflux pumps that export biofuel from the cell. We developed a model for cell growth and biofuel production and used it to compare several genetic control strategies for their ability to improve biofuel yields. We show that controlling efflux pump expression directly with a biofuel-responsive promoter is a straight forward way of improving biofuel production. In addition, a feed forward loop controller is shown to be versatile at dealing with uncertainty in biofuel production rates.

  17. Free Dietary Choice and Free-Range Rearing Improve the Product Quality, Gait Score, and Microbial Richness of Chickens

    Directory of Open Access Journals (Sweden)

    Siyu Chen

    2018-06-01

    Full Text Available Poultry welfare has been extensively studied; however, there is a lack of rigorous scientific knowledge relating to the different aspects of welfare factors and how this may contribute to the production quantity and product quality as well as the welfare of chickens. Therefore, we conducted an integrated study to compare welfare factors in chickens by providing free dietary choice under cage rearing, and further comparing cage rearing with free-range rearing. One hundred chickens each were allocated to a cage rearing group with conventional feeding (CC, a cage rearing group with free dietary choice of mealworms (FDM, a cage rearing group with free dietary choice of mealworms and fresh grass (FDMG, and a free-range rearing system group with free dietary choice of mealworms and fresh grass (FRMG. Results showed that under cage rearing, free dietary choice contributed to better meat quality and gait score, higher values of blood platelets, and a richer gut microbial composition, but poorer egg production than CC chickens. As compared to FDMG, FRMG chickens showed better meat quality, gait score, and feather conditions, as well as a richer gut microbial composition; however, they had poorer egg production and a poorer foot pad and foot feather condition. We conclude that free dietary choice and free-range rearing systems improve the product quality, gait score, and microbial richness of chickens.

  18. Photochemical and microbial alterations of DOM spectroscopic properties in the estuarine system Ria de Aveiro.

    Science.gov (United States)

    Santos, L; Santos, E B H; Dias, J M; Cunha, A; Almeida, A

    2014-08-01

    The influence of photochemical transformations of chromophoric dissolved organic matter (CDOM) on microbial communities was evaluated in the estuarine system Ria de Aveiro. Two sites, representative of the marine and brackish water zones of the estuary, were surveyed regularly in order to determine seasonal and vertical profiles of variation of CDOM properties. Optical parameters of CDOM indicative of aromaticity and molecular weight were used to establish CDOM sources, and microbial abundance and activity was characterized. Additionally, microcosm experiments were performed in order to simulate photochemical reactions of CDOM and to evaluate microbial responses to light-induced changes in CDOM composition. The CDOM of the two estuarine zones showed different spectral characteristics, with significantly higher values of the specific ultra-violet absorbance at 254 nm (SUVA254) (5.5 times) and of the absorption coefficient at 350 nm (a350) (12 times) and lower SR (S275-295/S350-400) ratio at brackish water compared with the marine zone, reflecting the different amounts and prevailing sources of organic matter, as well as distinct riverine and oceanic influences. At the marine zone, the abundance of bacteria and the activity of Leu-AMPase correlated with a350 and a254, suggesting a microbial contribution to the HMW CDOM pool. The irradiation of DOM resulted in a decrease of the values of a254 and a350 and an increase of the slope S275-295 and of the ratios E2 : E3 (a250/a365) and SR, which in turn increase its bioavailability. However, the extent of photoinduced transformations and microbial responses was dependent on the initial optical characteristics of CDOM. In Ria de Aveiro both photochemical and microbial processes yielded optical changes in CDOM and the overall results of these combined processes determine the fate of CDOM in the estuarine system and have an influence on local productivity and in adjacent coastal areas.

  19. Urban Transit System Microbial Communities Differ by Surface Type and Interaction with Humans and the Environment.

    Science.gov (United States)

    Hsu, Tiffany; Joice, Regina; Vallarino, Jose; Abu-Ali, Galeb; Hartmann, Erica M; Shafquat, Afrah; DuLong, Casey; Baranowski, Catherine; Gevers, Dirk; Green, Jessica L; Morgan, Xochitl C; Spengler, John D; Huttenhower, Curtis

    2016-01-01

    Public transit systems are ideal for studying the urban microbiome and interindividual community transfer. In this study, we used 16S amplicon and shotgun metagenomic sequencing to profile microbial communities on multiple transit surfaces across train lines and stations in the Boston metropolitan transit system. The greatest determinant of microbial community structure was the transit surface type. In contrast, little variation was observed between geographically distinct train lines and stations serving different demographics. All surfaces were dominated by human skin and oral commensals such as Propionibacterium , Corynebacterium , Staphylococcus , and Streptococcus . The detected taxa not associated with humans included generalists from alphaproteobacteria, which were especially abundant on outdoor touchscreens. Shotgun metagenomics further identified viral and eukaryotic microbes, including Propionibacterium phage and Malassezia globosa . Functional profiling showed that Propionibacterium acnes pathways such as propionate production and porphyrin synthesis were enriched on train holding surfaces (holds), while electron transport chain components for aerobic respiration were enriched on touchscreens and seats. Lastly, the transit environment was not found to be a reservoir of antimicrobial resistance and virulence genes. Our results suggest that microbial communities on transit surfaces are maintained from a metapopulation of human skin commensals and environmental generalists, with enrichments corresponding to local interactions with the human body and environmental exposures. IMPORTANCE Mass transit environments, specifically, urban subways, are distinct microbial environments with high occupant densities, diversities, and turnovers, and they are thus especially relevant to public health. Despite this, only three culture-independent subway studies have been performed, all since 2013 and all with widely differing designs and conclusions. In this study, we

  20. Progresses in the stable isotope studies of microbial processes associated with wetland methane production

    International Nuclear Information System (INIS)

    Li Qing; Lin Guanghui

    2013-01-01

    Methane emissions from wetlands play a key role in regulating global atmospheric methane concentration, so better understanding of microbial processes for the methane emission in wetlands is critical for developing process models and reducing uncertainty in global methane emission inventory. In this review, we describe basic microbial processes for wetland methane production and then demonstrate how stable isotope fractionation and stable isotope probing can be used to investigate the mechanisms underlying different methanogenic pathways and to quantify microbial species involved in wetland methane production. When applying stable isotope technique to calculate contributions of different pathways to the total methane production in various wetlands, the technical challenge is how to determine isotopic fractionation factors for the acetate derived methane production and carbon dioxide derived methane production. Although the application of stable isotope probing techniques to study the actual functions of different microbial organisms to methane production process is significantly superior to the traditional molecular biology method, the combination of these two technologies will be crucial for direct linking of the microbial community and functional structure with the corresponding metabolic functions, and provide new ideas for future studies. (authors)

  1. Synthetic Biology and Microbial Fuel Cells: Towards Self-Sustaining Life Support Systems

    Science.gov (United States)

    Hogan, John Andrew

    2014-01-01

    NASA ARC and the J. Craig Venter Institute (JCVI) collaborated to investigate the development of advanced microbial fuels cells (MFCs) for biological wastewater treatment and electricity production (electrogenesis). Synthetic biology techniques and integrated hardware advances were investigated to increase system efficiency and robustness, with the intent of increasing power self-sufficiency and potential product formation from carbon dioxide. MFCs possess numerous advantages for space missions, including rapid processing, reduced biomass and effective removal of organics, nitrogen and phosphorus. Project efforts include developing space-based MFC concepts, integration analyses, increasing energy efficiency, and investigating novel bioelectrochemical system applications

  2. Production of microbial biosurfactants: Status quo of rhamnolipid and surfactin towards large-scale production.

    Science.gov (United States)

    Henkel, Marius; Geissler, Mareen; Weggenmann, Fabiola; Hausmann, Rudolf

    2017-07-01

    Surfactants are an important class of industrial chemicals. Nowadays oleochemical surfactants such as alkyl polyglycosides (APGs) become increasingly important. This trend towards the utilization of renewable resources continues and consumers increasingly demand for environmentally friendly products. Consequently, research in microbial surfactants has drastically increased in the last years. While for mannosylerythritol lipids and sophorolipids established industrial processes exist, an implementation of other microbially derived surfactants has not yet been achieved. Amongst these biosurfactants, rhamnolipids synthesized by Pseudomonas aeruginosa and surfactin produced by Bacillus subtilis are so far the most analyzed biosurfactants due to their exceptional properties and the concomitant possible applications. In this review, a general overview is given regarding the current status of biosurfactants and benefits attributed to these molecules. Furthermore, the most recent research approaches for both rhamnolipids and surfactin are presented with respect to possible methods for industrial processes and the occurring drawbacks and limitations researchers have to address and overcome. Copyright © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Vegetable Production System (Veggie)

    Data.gov (United States)

    National Aeronautics and Space Administration — The Vegetable Production System (Veggie) was developed to be a simple, easily stowed, high growth volume, low resource facility capable of producing fresh vegetables...

  4. Systems biology solutions for biochemical production challenges

    DEFF Research Database (Denmark)

    Hansen, Anne Sofie Lærke; Lennen, Rebecca M; Sonnenschein, Nikolaus

    2017-01-01

    There is an urgent need to significantly accelerate the development of microbial cell factories to produce fuels and chemicals from renewable feedstocks in order to facilitate the transition to a biobased society. Methods commonly used within the field of systems biology including omics...... characterization, genome-scale metabolic modeling, and adaptive laboratory evolution can be readily deployed in metabolic engineering projects. However, high performance strains usually carry tens of genetic modifications and need to operate in challenging environmental conditions. This additional complexity...... compared to basic science research requires pushing systems biology strategies to their limits and often spurs innovative developments that benefit fields outside metabolic engineering. Here we survey recent advanced applications of systems biology methods in engineering microbial production strains...

  5. Systems biology solutions for biochemical production challenges.

    Science.gov (United States)

    Hansen, Anne Sofie Lærke; Lennen, Rebecca M; Sonnenschein, Nikolaus; Herrgård, Markus J

    2017-06-01

    There is an urgent need to significantly accelerate the development of microbial cell factories to produce fuels and chemicals from renewable feedstocks in order to facilitate the transition to a biobased society. Methods commonly used within the field of systems biology including omics characterization, genome-scale metabolic modeling, and adaptive laboratory evolution can be readily deployed in metabolic engineering projects. However, high performance strains usually carry tens of genetic modifications and need to operate in challenging environmental conditions. This additional complexity compared to basic science research requires pushing systems biology strategies to their limits and often spurs innovative developments that benefit fields outside metabolic engineering. Here we survey recent advanced applications of systems biology methods in engineering microbial production strains for biofuels and -chemicals. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  6. Subseafloor Microbial Life in Venting Fluids from the Mid Cayman Rise Hydrothermal System

    Science.gov (United States)

    Huber, J. A.; Reveillaud, J.; Reddington, E.; McDermott, J. M.; Sylva, S. P.; Breier, J. A.; German, C. R.; Seewald, J.

    2012-12-01

    In hard rock seafloor environments, fluids emanating from hydrothermal vents are one of the best windows into the subseafloor and its resident microbial community. The functional consequences of an extensive population of microbes living in the subseafloor remains unknown, as does our understanding of how these organisms interact with one another and influence the biogeochemistry of the oceans. Here we report the abundance, activity, and diversity of microbes in venting fluids collected from two newly discovered deep-sea hydrothermal vents along the ultra-slow spreading Mid-Cayman Rise (MCR). Fluids for geochemical and microbial analysis were collected from the Von Damm and Piccard vent fields, which are located within 20 km of one another, yet have extremely different thermal, geological, and depth regimes. Geochemical data indicates that both fields are highly enriched in volatiles, in particular hydrogen and methane, important energy sources for and by-products of microbial metabolism. At both sites, total microbial cell counts in the fluids ranged in concentration from 5 x 10 4 to 3 x 10 5 cells ml-1 , with background seawater concentrations of 1-2 x 10 4 cells ml-1 . In addition, distinct cell morphologies and clusters of cells not visible in background seawater were seen, including large filaments and mineral particles colonized by microbial cells. These results indicate local enrichments of microbial communities in the venting fluids, distinct from background populations, and are consistent with previous enumerations of microbial cells in venting fluids. Stable isotope tracing experiments were used to detect utilization of acetate, formate, and dissolve inorganic carbon and generation of methane at 70 °C under anaerobic conditions. At Von Damm, a putatively ultra-mafic hosted site located at ~2200 m with a maximum temperature of 226 °C, stable isotope tracing experiments indicate methanogenesis is occurring in most fluid samples. No activity was detected

  7. Trace Metal Requirements for Microbial Enzymes Involved in the Production and Consumption of Methane and Nitrous Oxide

    Science.gov (United States)

    Glass, Jennifer B.; Orphan, Victoria J.

    2011-01-01

    Fluxes of greenhouse gases to the atmosphere are heavily influenced by microbiological activity. Microbial enzymes involved in the production and consumption of greenhouse gases often contain metal cofactors. While extensive research has examined the influence of Fe bioavailability on microbial CO2 cycling, fewer studies have explored metal requirements for microbial production and consumption of the second- and third-most abundant greenhouse gases, methane (CH4), and nitrous oxide (N2O). Here we review the current state of biochemical, physiological, and environmental research on transition metal requirements for microbial CH4 and N2O cycling. Methanogenic archaea require large amounts of Fe, Ni, and Co (and some Mo/W and Zn). Low bioavailability of Fe, Ni, and Co limits methanogenesis in pure and mixed cultures and environmental studies. Anaerobic methane oxidation by anaerobic methanotrophic archaea (ANME) likely occurs via reverse methanogenesis since ANME possess most of the enzymes in the methanogenic pathway. Aerobic CH4 oxidation uses Cu or Fe for the first step depending on Cu availability, and additional Fe, Cu, and Mo for later steps. N2O production via classical anaerobic denitrification is primarily Fe-based, whereas aerobic pathways (nitrifier denitrification and archaeal ammonia oxidation) require Cu in addition to, or possibly in place of, Fe. Genes encoding the Cu-containing N2O reductase, the only known enzyme capable of microbial N2O conversion to N2, have only been found in classical denitrifiers. Accumulation of N2O due to low Cu has been observed in pure cultures and a lake ecosystem, but not in marine systems. Future research is needed on metalloenzymes involved in the production of N2O by enrichment cultures of ammonia oxidizing archaea, biological mechanisms for scavenging scarce metals, and possible links between metal bioavailability and greenhouse gas fluxes in anaerobic environments where metals may be limiting due to sulfide

  8. Conformations and molecular interactions of poly-γ-glutamic acid as a soluble microbial product in aqueous solutions

    OpenAIRE

    Wang, Ling-Ling; Chen, Jian-Tao; Wang, Long-Fei; Wu, Sha; Zhang, Guang-zhao; Yu, Han-Qing; Ye, Xiao-dong; Shi, Qing-Shan

    2017-01-01

    Soluble microbial products (SMPs) are of significant concern in the natural environment and in engineered systems. In this work, poly-γ-glutamic acid (γ-PGA), which is predominantly produced by Bacillus sp., was investigated in terms of pH-induced conformational changes and molecular interactions in aqueous solutions; accordingly, its sedimentation coefficient distribution and viscosity were also elucidated. Experimental results indicate that pH has a significant impact on the structure and m...

  9. Impact of feed carbohydrates and nitrogen source on the production of soluble microbial products (SMPs) in anaerobic digestion.

    Science.gov (United States)

    Le, Chencheng; Stuckey, David C

    2017-10-01

    Six stirred fill-and-draw batch reactors with a range of carbohydrate feeds (glucose, fructose and sucrose), and nitrogen sources (NH 4 Cl, urea) at various concentrations were used to investigate the effect of feed composition on the production of soluble microbial products (SMPs) during anaerobic digestion (AD). To gain greater insights into the SMPs produced, the composition of various fractions was analyzed, while the low molecular weight (MW) SMPs generated with different feeds and nutrients were collected and chemically analyzed using GC-MS. Other organic solutes such as free amino acids were determined using HPLC, and this level of chemical analysis has never been carried out in past work because of analytical limitations. It was found that the presence of ammonium salts rather than urea at 200 mg/L stimulated the production of not only volatile fatty acids, but also SMPs of different MW fractions, and reduced the production of biogas significantly. The study also revealed that the type of SMP that dominates in a particular system depends on the chemical characteristics of the feed, and this insight has implications on the composition of the effluent from anaerobic digesters (and their potential chlorination by-products), and membrane fouling in membrane bioreactors. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Microbial community structure and soil pH correspond to methane production in Arctic Alaska soils.

    Science.gov (United States)

    Wagner, Robert; Zona, Donatella; Oechel, Walter; Lipson, David

    2017-08-01

    While there is no doubt that biogenic methane production in the Arctic is an important aspect of global methane emissions, the relative roles of microbial community characteristics and soil environmental conditions in controlling Arctic methane emissions remains uncertain. Here, relevant methane-cycling microbial groups were investigated at two remote Arctic sites with respect to soil potential methane production (PMP). Percent abundances of methanogens and iron-reducing bacteria correlated with increased PMP, while methanotrophs correlated with decreased PMP. Interestingly, α-diversity of the methanogens was positively correlated with PMP, while β-diversity was unrelated to PMP. The β-diversity of the entire microbial community, however, was related to PMP. Shannon diversity was a better correlate of PMP than Simpson diversity across analyses, while rarefied species richness was a weak correlate of PMP. These results demonstrate the following: first, soil pH and microbial community structure both probably control methane production in Arctic soils. Second, there may be high functional redundancy in the methanogens with regard to methane production. Third, iron-reducing bacteria co-occur with methanogens in Arctic soils, and iron-reduction-mediated effects on methanogenesis may be controlled by α- and β-diversity. And finally, species evenness and rare species abundances may be driving relationships between microbial groups, influencing Arctic methane production. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  11. Reusing salad from salad bars – simulating the effects on product loss, microbial safety and product quality

    NARCIS (Netherlands)

    Tromp, S.O.; Rijgersberg, H.; Franz, E.

    2012-01-01

    The goal of this study is to model the effects of reusing salad from salad bars to reduce product loss, while keeping microbial safety and product quality at acceptable levels. We, therefore, expand our previously developed simulation model by incorporating reuse strategies and a quality decay

  12. Energy production systems engineering

    CERN Document Server

    Blair, Thomas Howard

    2017-01-01

    Energy Production Systems Engineering presents IEEE, Electrical Apparatus Service Association (EASA), and International Electrotechnical Commission (IEC) standards of engineering systems and equipment in utility electric generation stations. Electrical engineers that practice in the energy industry must understand the specific characteristics of electrical and mechanical equipment commonly applied to energy production and conversion processes, including the mechanical and chemical processes involved, in order to design, operate and maintain electrical systems that support and enable these processes. To aid this understanding, Energy Production Systems Engineeringdescribes the equipment and systems found in various types of utility electric generation stations. This information is accompanied by examples and practice problems. It also addresses common issues of electrical safety that arise in electric generation stations.

  13. Production of wax esters via microbial oil synthesis from food industry waste and by-product streams.

    Science.gov (United States)

    Papadaki, Aikaterini; Mallouchos, Athanasios; Efthymiou, Maria-Nefeli; Gardeli, Chryssavgi; Kopsahelis, Nikolaos; Aguieiras, Erika C G; Freire, Denise M G; Papanikolaou, Seraphim; Koutinas, Apostolis A

    2017-12-01

    The production of wax esters using microbial oils was demonstrated in this study. Microbial oils produced from food waste and by-product streams by three oleaginous yeasts were converted into wax esters via enzymatic catalysis. Palm oil was initially used to evaluate the influence of temperature and enzyme activity on wax ester synthesis catalysed by Novozyme 435 and Lipozyme lipases using cetyl, oleyl and behenyl alcohols. The highest conversion yields (up to 79.6%) were achieved using 4U/g of Novozyme 435 at 70°C. Transesterification of microbial oils to behenyl and cetyl esters was achieved at conversion yields up to 87.3% and 69.1%, respectively. Novozyme 435 was efficiently reused for six and three cycles during palm esters and microbial esters synthesis, respectively. The physicochemical properties of microbial oil derived behenyl esters were comparable to natural waxes. Wax esters from microbial oils have potential applications in cosmetics, chemical and food industries. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Innovative microbial fuel cell for electricity production from anaerobic reactors

    DEFF Research Database (Denmark)

    Min, Booki; Angelidaki, Irini

    2008-01-01

    A submersible microbial fuel cell (SMFC) was developed by immersing an anode electrode and a cathode chamber in an anaerobic reactor. Domestic wastewater was used as the medium and the inoculum in the experiments. The SMFC could successfully generate a stable voltage of 0.428 ± 0.003 V with a fixed......, a large portion of voltage drop was caused by the ohmic (electrolyte) resistance of the medium present between two electrodes, although the two electrodes were closely positioned (about 3 cm distance; internal resistance = 35 ± 2 Ω). The open circuit potential (0.393 V vs. a standard hydrogen electrode...

  15. Synthetic biology for microbial production of lipid-based biofuels.

    Science.gov (United States)

    d'Espaux, Leo; Mendez-Perez, Daniel; Li, Rachel; Keasling, Jay D

    2015-12-01

    The risks of maintaining current CO2 emission trends have led to interest in producing biofuels using engineered microbes. Microbial biofuels reduce emissions because CO2 produced by fuel combustion is offset by CO2 captured by growing biomass, which is later used as feedstock for biofuel fermentation. Hydrocarbons found in petroleum fuels share striking similarity with biological lipids. Here we review synthetic metabolic pathways based on fatty acid and isoprenoid metabolism to produce alkanes and other molecules suitable as biofuels. We further discuss engineering strategies to optimize engineered biosynthetic routes, as well as the potential of synthetic biology for sustainable manufacturing. Published by Elsevier Ltd.

  16. Synthetic biology for microbial production of lipid-based biofuels

    Energy Technology Data Exchange (ETDEWEB)

    d' Espaux, L; Mendez-Perez, D; Li, R; Keasling, JD

    2015-10-23

    The risks of maintaining current CO2 emission trends have led to interest in producing biofuels using engineered microbes. Microbial biofuels reduce emissions because CO2 produced by fuel combustion is offset by CO2 captured by growing biomass, which is later used as feedstock for biofuel fermentation. Hydrocarbons found in petroleum fuels share striking similarity with biological lipids. Here in this paper we review synthetic metabolic pathways based on fatty acid and isoprenoid metabolism to produce alkanes and other molecules suitable as biofuels. Lastly, we further discuss engineering strategies to optimize engineered biosynthetic routes, as well as the potential of synthetic biology for sustainable manufacturing.

  17. Developing Model Benchtop Systems for Microbial Experimental Evolution

    Science.gov (United States)

    Gentry, D.; Wang, J.; Arismendi, D.; Alvarez, J.; Ouandji, C.; Blaich, J.

    2017-12-01

    Understanding how microbes impact an ecosystem has improved through advances of molecular and genetic tools, but creating complex systems that emulate natural biology goes beyond current technology. In fact, many chemical, biological, and metabolic pathways of even model organisms are still poorly characterized. Even then, standard laboratory techniques for testing microbial impact on environmental change can have many drawbacks; they are time-consuming, labor intensive, and are at risk of contamination. By having an automated process, many of these problems can be reduced or even eliminated. We are developing a benchtop system that can run for long periods of time without the need for human intervention, involve multiple environmental stressors at once, perform real-time adjustments of stressor exposure based on current state of the population, and minimize contamination risks. Our prototype device allows operators to generate an analogue of real world micro-scale ecosystems that can be used to model the effects of disruptive environmental change on microbial ecosystems. It comprises of electronics, mechatronics, and fluidics based systems to control, measure, and evaluate the before and after state of microbial cultures from exposure to environmental stressors. Currently, it uses four parallel growth chambers to perform tests on liquid cultures. To measure the population state, optical sensors (LED/photodiode) are used. Its primary selection pressure is UV-C radiation, a well-studied stressor known for its cell- and DNA- damaging effects and as a mutagen. Future work will involve improving the current growth chambers, as well as implementing additional sensors and environmental stressors into the system. Full integration of multiple culture testing will allow inter-culture comparisons. Besides the temperature and OD sensors, other types of sensors can be integrated such as conductivity, biomass, pH, and dissolved gasses such as CO2 and O2. Additional

  18. Innovativeness in production systems

    DEFF Research Database (Denmark)

    Blichfeldt, Henrik; Knudsen, Mette Præst

    Alignment of market demand and manufacturing capabilities are directly linked to the potential competitive advantage. Pressure for manufacturing companies to customize increase the need for productions systems to handle innovations, especially in SMEs. The paper claims that innovativeness has...... a positive influence of the ability of the manufacturing system to provide specific capabilities that enables the entire production system to positively influence the competitiveness. A comparative case study of three SMEs shows that competitive advantages are obtained through innovative technologies......, but revealed also automation potential in data and information management to be more responsive and cost-effective....

  19. Changes in Rumen Microbial Community Composition during Adaption to an In Vitro System and the Impact of Different Forages.

    Directory of Open Access Journals (Sweden)

    Melanie B Lengowski

    Full Text Available This study examined ruminal microbial community composition alterations during initial adaption to and following incubation in a rumen simulation system (Rusitec using grass or corn silage as substrates. Samples were collected from fermenter liquids at 0, 2, 4, 12, 24, and 48 h and from feed residues at 0, 24, and 48 h after initiation of incubation (period 1 and on day 13 (period 2. Microbial DNA was extracted and real-time qPCR was used to quantify differences in the abundance of protozoa, methanogens, total bacteria, Fibrobacter succinogenes, Ruminococcus albus, Ruminobacter amylophilus, Prevotella bryantii, Selenomonas ruminantium, and Clostridium aminophilum. We found that forage source and sampling time significantly influenced the ruminal microbial community. The gene copy numbers of most microbial species (except C. aminophilum decreased in period 1; however, adaption continued through period 2 for several species. The addition of fresh substrate in period 2 led to increasing copy numbers of all microbial species during the first 2-4 h in the fermenter liquid except protozoa, which showed a postprandial decrease. Corn silage enhanced the growth of R. amylophilus and F. succinogenes, and grass silage enhanced R. albus, P. bryantii, and C. aminophilum. No effect of forage source was detected on total bacteria, protozoa, S. ruminantium, or methanogens or on total gas production, although grass silage enhanced methane production. This study showed that the Rusitec provides a stable system after an adaption phase that should last longer than 48 h, and that the forage source influenced several microbial species.

  20. Utilization of subsurface microbial electrochemical systems to elucidate the mechanisms of competition between methanogenesis and microbial iron(III)/humic acid reduction in Arctic peat soils

    Science.gov (United States)

    Friedman, E. S.; Miller, K.; Lipson, D.; Angenent, L. T.

    2012-12-01

    High-latitude peat soils are a major carbon reservoir, and there is growing concern that previously dormant carbon from this reservoir could be released to the atmosphere as a result of continued climate change. Microbial processes, such as methanogenesis and carbon dioxide production via iron(III) or humic acid reduction, are at the heart of the carbon cycle in Arctic peat soils [1]. A deeper understanding of the factors governing microbial dominance in these soils is crucial for predicting the effects of continued climate change. In previous years, we have demonstrated the viability of a potentiostatically-controlled subsurface microbial electrochemical system-based biosensor that measures microbial respiration via exocellular electron transfer [2]. This system utilizes a graphite working electrode poised at 0.1 V NHE to mimic ferric iron and humic acid compounds. Microbes that would normally utilize these compounds as electron acceptors donate electrons to the electrode instead. The resulting current is a measure of microbial respiration with the electrode and is recorded with respect to time. Here, we examine the mechanistic relationship between methanogenesis and iron(III)- or humic acid-reduction by using these same microbial-three electrode systems to provide an inexhaustible source of alternate electron acceptor to microbes in these soils. Chamber-based carbon dioxide and methane fluxes were measured from soil collars with and without microbial three-electrode systems over a period of four weeks. In addition, in some collars we simulated increased fermentation by applying acetate treatments to understand possible effects of continued climate change on microbial processes in these carbon-rich soils. The results from this work aim to increase our fundamental understanding of competition between electron acceptors, and will provide valuable data for climate modeling scenarios. 1. Lipson, D.A., et al., Reduction of iron (III) and humic substances plays a major

  1. The shift of microbial communities and their roles in sulfur and iron cycling in a copper ore bioleaching system

    Science.gov (United States)

    Niu, Jiaojiao; Deng, Jie; Xiao, Yunhua; He, Zhili; Zhang, Xian; van Nostrand, J. D.; Liang, Yili; Deng, Ye; Liu, Xueduan; Yin, Huaqun

    2016-10-01

    Bioleaching has been employed commercially to recover metals from low grade ores, but the production efficiency remains to be improved due to limited understanding of the system. This study examined the shift of microbial communities and S&Fe cycling in three subsystems within a copper ore bioleaching system: leaching heap (LH), leaching solution (LS) and sediment under LS. Results showed that both LH and LS had higher relative abundance of S and Fe oxidizing bacteria, while S and Fe reducing bacteria were more abundant in the Sediment. GeoChip analysis showed a stronger functional potential for S0 oxidation in LH microbial communities. These findings were consistent with measured oxidation activities to S0 and Fe2+, which were highest by microbial communities from LH, lower by those from LS and lowest form Sediment. Moreover, phylogenetic molecular ecological network analysis indicated that these differences might be related to interactions among microbial taxa. Last but not the least, a conceptual model was proposed, linking the S&Fe cycling with responsible microbial populations in the bioleaching systems. Collectively, this study revealed the microbial community and functional structures in all three subsystems of the copper ore, and advanced a holistic understanding of the whole bioleaching system.

  2. Technological trends and market perspectives for production of microbial oils rich in omega-3.

    Science.gov (United States)

    Finco, Ana Maria de Oliveira; Mamani, Luis Daniel Goyzueta; Carvalho, Júlio Cesar de; de Melo Pereira, Gilberto Vinícius; Thomaz-Soccol, Vanete; Soccol, Carlos Ricardo

    2017-08-01

    In recent years, foods that contain omega-3 lipids have emerged as important promoters of human health. These lipids are essential for the functional development of the brain and retina, and reduction of the risk of cardiovascular and Alzheimer's diseases. The global market for omega-3 production, particularly docosahexaenoic acid (DHA), saw a large expansion in the last decade due to the increasing use of this lipid as an important component of infant food formulae and supplements. The production of omega-3 lipids from fish and vegetable oil sources has some drawbacks, such as complex purification procedures, unwanted contamination by marine pollutants, reduction or even extinction of several species of fish, and aspects related to sustainability. A promising alternative system for the production of omega-3 lipids is from microbial metabolism of yeast, fungi, or microalgae. The aim of this review is to discuss the various omega-3 sources in the context of the global demand and market potential for these bioactive compounds. To summarize, it is clear that fish and vegetable oil sources will not be sufficient to meet the future needs of the world population. The biotechnological production of single-cell oil comes as a sustainable alternative capable of supplementing the global demand for omega-3, causing less environmental impact.

  3. ATLAS production system

    CERN Document Server

    Borodin, Mikhail; The ATLAS collaboration; De, Kaushik; Klimentov, Alexei; Golubkov, Dmitry; Maeno, Tadashi; Mashinistov, Ruslan; Wenaus, Torre; Padolski, Siarhei

    2016-01-01

    The second generation of the ATLAS production system called ProdSys2 is a distributed workload manager which used by thousands of physicists to analyze the data remotely, with the volume of processed data is beyond the exabyte scale, across a more than hundred heterogeneous sites. It achieves high utilization by combining dynamic job definition based on many criterias, such as input and output size, memory requirements and CPU consumption with manageable scheduling policies and by supporting different kind of computational resources, such as GRID, clouds, supercomputers and volunteering computers. Besides jobs definition Production System also includes flexible web user interface, which implements user-friendly environment for main ATLAS workflows, e.g. simple way of combining different data flows, and real-time monitoring, optimised for using with huge amount of information to present. We present an overview of the ATLAS Production System major components: job and task definition, workflow manager web user i...

  4. Oil production system

    Energy Technology Data Exchange (ETDEWEB)

    Ballantyne, J F

    1983-12-21

    A new oil producing system is proposed which consists of a group of underwater wells, an underwater riser and a floating storage facility for the production of the wells. The group of wells and the riser are interconnected through a manifold system in such a way that the production from any well or from the entire group of wells go to the base (foundation) of the riser. From above the riser is connected with the floating storage facility which is equipped, besides tanks for storing the well products, with a separation device for separating the oil and the accompanying gas. The gas is used as a fuel for producing electric power required by the dynamic positioning systems. The products from each well are tested by means of a regulable coupling controlled by means of a cable, which is passed from the surface through the riser. The wellhead equipment for the unslanted wells is mounted on a template previously installed on the sea floor. From the template the well products enter the riser through the manifold unit system.

  5. 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)

  6. Development of Production Systems

    DEFF Research Database (Denmark)

    Christiansen, Thomas Bøhm

    1997-01-01

    This paper presents the initial considerations related to a Ph.D. study initiated at IPV, DTU in February 1997, concerning the research subject "Development of Production Systems". The content and aim of this paper is to 1) to introduce the study by......This paper presents the initial considerations related to a Ph.D. study initiated at IPV, DTU in February 1997, concerning the research subject "Development of Production Systems". The content and aim of this paper is to 1) to introduce the study by...

  7. Relevance of microbial finished product testing in food safety management

    NARCIS (Netherlands)

    Zwietering, M.H.; Jacxsens, L.; Membre, J.M.; Nauta, M.; Peterz, M.

    2016-01-01

    Management of microbiological food safety is largely based on good design of processes, products and procedures. Finished product testing may be considered as a control measure at the end of the production process. However, testing gives only very limited information on the safety status of a food.

  8. Developments in commercially produced microbials at Biochem Products

    Science.gov (United States)

    John Lublinkhof; Douglas H. Ross

    1985-01-01

    Biochem Products is part of a large industrial and scientific family - the Solvay Group. Solvay, headquartered in Brussels, Belgium is a multinational company with 46,000 employees worldwide. In the U.S., our working partners include a large polymer manufacturer, a peroxygen producer and a leading poultry and animal health products company. Biochem Products is a...

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

    Directory of Open Access Journals (Sweden)

    Krystal de Alcantara Notaro

    2014-04-01

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

  10. A batch assay to measure microbial hydrogen sulfide production from sulfur-containing solid wastes

    International Nuclear Information System (INIS)

    Sun, Mei; Sun, Wenjie; Barlaz, Morton A.

    2016-01-01

    Large volumes of sulfur-containing wastes enter municipal solid waste landfills each year. Under the anaerobic conditions that prevail in landfills, oxidized forms of sulfur, primarily sulfate, are converted to sulfide. Hydrogen sulfide (H 2 S) is corrosive to landfill gas collection and treatment systems, and its presence in landfill gas often necessitates the installation of expensive removal systems. For landfill operators to understand the cost of managing sulfur-containing wastes, an estimate of the H 2 S production potential is needed. The objective of this study was to develop and demonstrate a biochemical sulfide potential (BSP) test to measure the amount of H 2 S produced by different types of sulfur-containing wastes in a relatively fast (30 days) and inexpensive (125 mL serum bottles) batch assay. This study confirmed the toxic effect of H 2 S on both sulfate reduction and methane production in batch systems, and demonstrated that removing accumulated H 2 S by base adsorption was effective for mitigating inhibition. H 2 S production potentials of coal combustion fly ash, flue gas desulfurization residual, municipal solid waste combustion ash, and construction and demolition waste were determined in BSP assays. After 30 days of incubation, most of the sulfate in the wastes was converted to gaseous or aqueous phase sulfide, with BSPs ranging from 0.8 to 58.8 mL H 2 S/g waste, depending on the chemical composition of the samples. Selected samples contained solid phase sulfide which contributed to the measured H 2 S yield. A 60 day incubation in selected samples resulted in 39–86% additional sulfide production. H 2 S production measured in BSP assays was compared with that measured in simulated landfill reactors and that calculated from chemical analyses. H 2 S production in BSP assays and in reactors was lower than the stoichiometric values calculated from chemical composition for all wastes tested, demonstrating the importance of assays to estimate the

  11. A batch assay to measure microbial hydrogen sulfide production from sulfur-containing solid wastes

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Mei, E-mail: msun8@uncc.edu [Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Campus Box 7908, Raleigh, NC (United States); Sun, Wenjie, E-mail: wsun@smu.edu [Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Campus Box 7908, Raleigh, NC (United States); Department of Civil and Environmental Engineering, Southern Methodist University, PO Box 750340, Dallas, TX (United States); Barlaz, Morton A., E-mail: barlaz@ncsu.edu [Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Campus Box 7908, Raleigh, NC (United States)

    2016-05-01

    Large volumes of sulfur-containing wastes enter municipal solid waste landfills each year. Under the anaerobic conditions that prevail in landfills, oxidized forms of sulfur, primarily sulfate, are converted to sulfide. Hydrogen sulfide (H{sub 2}S) is corrosive to landfill gas collection and treatment systems, and its presence in landfill gas often necessitates the installation of expensive removal systems. For landfill operators to understand the cost of managing sulfur-containing wastes, an estimate of the H{sub 2}S production potential is needed. The objective of this study was to develop and demonstrate a biochemical sulfide potential (BSP) test to measure the amount of H{sub 2}S produced by different types of sulfur-containing wastes in a relatively fast (30 days) and inexpensive (125 mL serum bottles) batch assay. This study confirmed the toxic effect of H{sub 2}S on both sulfate reduction and methane production in batch systems, and demonstrated that removing accumulated H{sub 2}S by base adsorption was effective for mitigating inhibition. H{sub 2}S production potentials of coal combustion fly ash, flue gas desulfurization residual, municipal solid waste combustion ash, and construction and demolition waste were determined in BSP assays. After 30 days of incubation, most of the sulfate in the wastes was converted to gaseous or aqueous phase sulfide, with BSPs ranging from 0.8 to 58.8 mL H{sub 2}S/g waste, depending on the chemical composition of the samples. Selected samples contained solid phase sulfide which contributed to the measured H{sub 2}S yield. A 60 day incubation in selected samples resulted in 39–86% additional sulfide production. H{sub 2}S production measured in BSP assays was compared with that measured in simulated landfill reactors and that calculated from chemical analyses. H{sub 2}S production in BSP assays and in reactors was lower than the stoichiometric values calculated from chemical composition for all wastes tested, demonstrating

  12. Photochemical hydrogen production system

    International Nuclear Information System (INIS)

    Copeland, R.J.

    1990-01-01

    Both technical and economic factors affect the cost of producing hydrogen by photochemical processes. Technical factors include the efficiency and the capital and operating costs of the renewable hydrogen conversion system; economic factors include discount rates, economic life, credit for co-product oxygen, and the value of the energy produced. This paper presents technical and economic data for a system that generates on-peak electric power form photochemically produced hydrogen

  13. Bioelectrochemical systems (BES) for sustainable energy production and product recovery from organic wastes and industrial wastewaters

    DEFF Research Database (Denmark)

    Pant, Deepak; Singh, Anoop; Van Bogaert, Gilbert

    2012-01-01

    Bioelectrochemical systems (BESs) are unique systems capable of converting the chemical energy of organic waste including low-strength wastewaters and lignocellulosic biomass into electricity or hydrogen/chemical products in microbial fuel cells (MFCs) or microbial electrolysis cells (MECs......) respectively, or other products formed at the cathode by an electrochemical reduction process. As compared to conventional fuel cells, BESs operate under relatively mild conditions, use a wide variety of organic substrates and mostly do not use expensive precious metals as catalysts. The recently discovered...... use of BES for product synthesis via microbial electrosynthesis have greatly expanded the horizon for these systems. Newer concepts in application as well as development of alternative materials for electrodes, separators, and catalysts, along with innovative designs have made BESs very promising...

  14. Independence and Product Systems

    OpenAIRE

    Skeide, Michael

    2003-01-01

    Starting from elementary considerations about independence and Markov processes in classical probability we arrive at the new concept of conditional monotone independence (or operator-valued monotone independence). With the help of product systems of Hilbert modules we show that monotone conditional independence arises naturally in dilation theory.

  15. Effects of organic loading rate on biogas production from macroalgae: Performance and microbial community structure.

    Science.gov (United States)

    Sun, Meng-Ting; Fan, Xiao-Lei; Zhao, Xiao-Xian; Fu, Shan-Fei; He, Shuai; Manasa, M R K; Guo, Rong-Bo

    2017-07-01

    Macroalgae biomass has been considered as a promising feedstock for biogas production. In order to improve the efficiency of anaerobic digestion (AD) of macroalgae, semi-continuous fermentation was conducted to examine the effects of organic loading rate (OLR) on biogas production from Macrocystis pyrifer. Results showed that, under OLRs of 1.37, 2.74, 4.12 and 6.85kgVS substrate /(m 3 ·d), the average unit biogas yields were 438.9, 477.3, 480.1 and 188.7mL/(gVS substrate d), respectively. It indicated that biogas production was promoted by the increased OLR in an appropriate range while inhibited by the OLR beyond the appropriate range. The investigation on physical-chemical parameters revealed that unfavorable VFAs concentration, pH and salinity might be the main causes for system failure due to the overrange OLR, while the total phenols failed to reach the inhibitory concentration. Microbial community analysis demonstrated that several bacterial and archaeal phyla altered with increase in OLR apparently. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Microbial dynamics during production of lesser mealworms (Alphitobius diaperinus) for human consumption at industrial scale.

    Science.gov (United States)

    Wynants, E; Crauwels, S; Verreth, C; Gianotten, N; Lievens, B; Claes, J; Van Campenhout, L

    2018-04-01

    In this study, the microbial dynamics during an industrial production cyle of lesser mealworms (Alphitobius diaperinus), sold for human consumption, were characterised. The microbial numbers as well as the microbial diversity were generally higher for the substrate, existing of remaining feed, faeces and exuviae, than for the larvae. Most of the species-level operational taxonomic units, identified using Illumina MiSeq sequencing, that were present in the feed were also detected in the larvae and vice versa. However, bacterial diversity decreased in the larvae during rearing. These results suggested that the feed is an important determinant of the insect bacterial community, but that some bacterial species show a competitive advantage inside the insect gut and become dominant. A blanching treatment of the larvae after harvest reduced most microbial counts, but the number of aerobic endospores remained at 4.0 log cfu/g. Whereas food pathogens Salmonella spp., Listeria monocytogenes, Bacillus cereus or coagulase-positive staphylococci were not detected in our study, fungal isolates corresponding to the genera Aspergillus and Fusarium were recovered. Therefore, it cannot be excluded that mycotoxins were present. The results of this study contribute to a better understanding of the microbial dynamics and food safety aspects during the production of edible insects. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Simultaneous electricity production and antibiotics removal by microbial fuel cells.

    Science.gov (United States)

    Zhou, Ying; Zhu, Nengwu; Guo, Wenying; Wang, Yun; Huang, Xixian; Wu, Pingxiao; Dang, Zhi; Zhang, Xiaoping; Xian, Jinchan

    2018-04-07

    The removal of antibiotics is crucial for improvement of water quality in animal wastewater treatment. In this paper, the performance of microbial fuel cell (MFC) in terms of degradation of typical antibiotics was investigated. Electricity was successfully produced by using sludge supernatant mixtures and synthesized animal wastewater as inoculation in MFC. Results demonstrated that the stable voltage, the maximum power density and internal resistance of anaerobic self-electrolysis (ASE) -112 and ASE-116 without antibiotics addition were 0.574 V, 5.78 W m -3 and 28.06 Ω, and 0.565 V, 5.82 W m -3 and 29.38 Ω, respectively. Moreover, when adding aureomycin, sulfadimidine, roxithromycin and norfloxacin into the reactors, the performance of MFC was inhibited (0.51 V-0.41 V), while the output voltage was improved with the decreased concentration of antibiotics. However, the removal efficiency of ammonia nitrogen (NH 3 -N) and total phosphorus (TP) were both obviously enhanced. Simultaneously, LC-MS analysis showed that the removal efficiency of aureomycin, roxithromycin and norfloxacin were all 100% and the removal efficiency of sulfadimidine also reached 99.9%. These results indicated that antibiotics displayed significantly inhibitions for electricity performance but improved the quality of water simultaneously. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Organic acid production from potato starch waste fermentation by rumen microbial communities from Dutch and Thai dairy cows

    NARCIS (Netherlands)

    Palakawong Na Ayudthaya, Susakul; De Weijer, Van Antonius H.P.; Gelder, Van Antonie H.; Stams, Alfons J.M.; Vos, De Willem M.; Plugge, Caroline M.

    2018-01-01

    Background: Exploring different microbial sources for biotechnological production of organic acids is important. Dutch and Thai cow rumen samples were used as inocula to produce organic acid from starch waste in anaerobic reactors. Organic acid production profiles were determined and microbial

  19. Microbial Diversity in Soil Treatment Systems for Wastewater

    Science.gov (United States)

    Van Cuyk, S.; Spear, J.; Siegrist, R.; Pace, N.

    2002-05-01

    There is an increasing awareness and concern over land based wastewater system performance with respect to the removal of bacteria and virus. The goal of this work is to describe and identify the organismal composition of the microbiota in the applied wastewater effluent, the rich biomat that develops at the infiltrative surface, and in the soil percolate in order to aid in the understanding of bacterial and virus purification in soil treatment systems. The traditional reliance on pure culture techniques to describe microbiota is circumvented by the employment of a molecular approach. Microbial community characterization is underway based on cloning and sequencing of 16S rRNA genes for phylogenetic analyses, to determine the nature and quantity of microbiota that constitute these ecosystems. Knowledge of the organisms naturally present can influence the design and treatment capacity of these widely used land based systems. Laboratory, intermediate and field scale systems are currently under study. Since human pathogens are known to exist in sewage effluents, their removal in wastewater infiltration systems and within the underlying soil are in need of a more fundamental understanding. The relationship between design parameters and environmental conditions, including a microbial characterization, is essential for the prevention of contamination in groundwater sources. Preliminary results indicate the presence of uncultured organisms and phylogenetic kinds that had not been detected in these systems using other methods. Acinetobacter johnsonii and Acrobacter cryaerophilus were the two dominant species found in septic tank effluent, comprising 20% and 11% of the library respectively. In soil samples collected from the infiltrative surface of a column dosed with STE, there was no dominant bacterial species present. Percolate samples collected from the outflow of the column showed that a tuber borchii symbiont, a common soil microorganism, dominated the bacterial

  20. Bioelectrochemical Systems for Indirect Biohydrogen Production

    KAUST Repository

    Regan, John M.

    2014-01-01

    Bioelectrochemical systems involve the use of exoelectrogenic (i.e., anode-reducing) microbes to produce current in conjunction with the oxidation of reduced compounds. This current can be used directly for power in a microbial fuel cell, but there are alternate uses of this current. One such alternative is the production of hydrogen in a microbial electrolysis cell (MEC), which accomplishes cathodic proton reduction with a slight applied potential by exploiting the low redox potential produced by exoelectrogens at the anode. As an indirect approach to biohydrogen production, these systems are not subject to the hydrogen yield constraints of fermentative processes and have been proven to work with virtually any biodegradable organic substrate. With continued advancements in reactor design to reduce the system internal resistance, increase the specific surface area for anode biofilm development, and decrease the material costs, MECs may emerge as a viable alternative technology for biohydrogen production. Moreover, these systems can also incorporate other value-added functionalities for applications in waste treatment, desalination, and bioremediation.

  1. Methane production from formate, acetate and H2/CO2; focusing on kinetics and microbial characterization

    DEFF Research Database (Denmark)

    Pan, Xiaofang; Angelidaki, Irini; Alvarado-Morales, Merlin

    2016-01-01

    For evaluating the methanogenesis from typical methanogenic precursors (formate, acetate and H-2/CO2), CH4 production kinetics were investigated at 37 +/- 1 degrees C in batch anaerobic digestion tests and stimulated by modified Gompertz model. The results showed that maximum methanation rate from...... formate, acetate and H-2/CO2 were 19.58 +/- 0.49, 42.65 +/- 1.17 and 314.64 +/- 3.58 N mL/gVS/d in digested manure system and 6.53 +/- 0.31, 132.04 +/- 3.96 and 640.16 +/- 19.92 N mL/gVS/d in sewage sludge system during second generation incubation. Meanwhile the model could not fit well in granular...... sludge system, while the rate of formate methanation was faster than from H-2/CO2 and acetate. Considering both the kinetic results and microbial assay we could conclude that H-2/CO2 methanation was the fastest methanogenic step in digested manure and sewage sludge system with Methanomicrobiales...

  2. High hydrogen production from glycerol or glucose by electrohydrogenesis using microbial electrolysis cells

    KAUST Repository

    Selembo, Priscilla A.; Perez, Joe M.; Lloyd, Wallis A.; Logan, Bruce E.

    2009-01-01

    The use of glycerol for hydrogen gas production was examined via electrohydrogenesis using microbial electrolysis cells (MECs). A hydrogen yield of 3.9 mol-H2/mol was obtained using glycerol, which is higher than that possible by fermentation

  3. Fed-batch fermentation dealing with nitrogen limitation in microbial transglutaminase production by Streptoverticillium mobaraense

    NARCIS (Netherlands)

    Rinzema, A; Tramper, J; de Bruin, E; Bol, J

    In the later stages of a batch fermentation for microbial transglutaminase production by Streptoverticillium mobaraense the availability of a nitrogen source accessible to the microorganism becomes critical. Fed-batch fermentation is investigated with the aim of avoiding this substrate limitation.

  4. 40 CFR 158.2171 - Experimental use permit microbial pesticides product analysis data requirements table.

    Science.gov (United States)

    2010-07-01

    ... conducted at the point in the production process after which there would be no potential for microbial... Identity R MP EP -- 885.1200 Manufacturing process R TGAI and MP TGAI and EP 1, 2 Deposition of a sample in... -- 830.6313 Stability to normal and elevated temperatures, metals and metal ions R TGAI TGAI -- 830.6317...

  5. Microbial analysis of meat and meat products sold in fast food ...

    African Journals Online (AJOL)

    The present study was carried out to investigate the rate of microbial contamination of ready-to-eat meat and meat products sold in different fast food restaurants in Aba. This study was carried out between June and August, 2015. Samples were collected aseptically from five fast food restaurants using sterile polythene bags.

  6. Microbial electrolysis contribution to anaerobic digestion of waste activated sludge, leading to accelerated methane production

    DEFF Research Database (Denmark)

    Liu, Wenzong; Cai, Weiwei; Guo, Zechong

    2016-01-01

    Methane production rate (MPR) in waste activated sludge (WAS) digestion processes is typically limitedby the initial steps of complex organic matter degradation, leading to a limited MPR due to sludgefermentation speed of solid particles. In this study, a novel microbial electrolysis AD reactor (ME...

  7. MILK KEFIR: COMPOSITION, MICROBIAL CULTURES, BIOLOGICAL ACTIVITIES AND RELATED PRODUCTS

    Directory of Open Access Journals (Sweden)

    Maria Rosa Prado

    2015-10-01

    Full Text Available In recent years, there has been a strong focus on beneficial foods with probiotic microorganisms and functional organic substances. In this context, there is an increasing interest in the commercial use of kefir, since it can be marketed as a natural beverage that has health promoting bacteria. There are numerous commercially available kefir based-products. Kefir may act as a matrix in the effective delivery of probiotic microorganisms in different types of products. Also, the presence of kefir’s exopolysaccharides, known as kefiran, which has biological activity, certainly adds value to products. Kefiran can also be used separately in other food products and as a coating film for various food and pharmaceutical products. This article aims to update the information about kefir and its microbiological composition, biological activity of the kefir’s microflora and the importance of kefiran as a beneficial health substance.

  8. Milk kefir: composition, microbial cultures, biological activities, and related products.

    Science.gov (United States)

    Prado, Maria R; Blandón, Lina Marcela; Vandenberghe, Luciana P S; Rodrigues, Cristine; Castro, Guillermo R; Thomaz-Soccol, Vanete; Soccol, Carlos R

    2015-01-01

    In recent years, there has been a strong focus on beneficial foods with probiotic microorganisms and functional organic substances. In this context, there is an increasing interest in the commercial use of kefir, since it can be marketed as a natural beverage that has health promoting bacteria. There are numerous commercially available kefir based-products. Kefir may act as a matrix in the effective delivery of probiotic microorganisms in different types of products. Also, the presence of kefir's exopolysaccharides, known as kefiran, which has biological activity, certainly adds value to products. Kefiran can also be used separately in other food products and as a coating film for various food and pharmaceutical products. This article aims to update the information about kefir and its microbiological composition, biological activity of the kefir's microflora and the importance of kefiran as a beneficial health substance.

  9. Development of Electro-Microbial Carbon Capture and Conversion Systems

    KAUST Repository

    Al Rowaihi, Israa S.

    2017-05-01

    Carbon dioxide is a viable resource, if used as a raw material for bioprocessing. It is abundant and can be collected as a byproduct from industrial processes. Globally, photosynthetic organisms utilize around 6’000 TW (terawatt) of solar energy to fix ca. 800 Gt (gigaton) of CO2 in the planets largest carbon-capture process. Photosynthesis combines light harvesting, charge separation, catalytic water splitting, generation of reduction equivalents (NADH), energy (ATP) production and CO2 fixation into one highly interconnected and regulated process. While this simplicity makes photosynthetic production of commodity interesting, yet photosynthesis suffers from low energy efficiency, which translates in an extensive footprint for solar biofuels production conditions that store < 2% of solar energy. Electron transfer processes form the core of photosynthesis. At moderate light intensity, the electron transport chains reach maximum transfer rates and only work when photons are at appropriate wavelengths, rendering the process susceptible to oxidative damage, which leads to photo-inhibition and loss of efficiency. Based on our fundamental analysis of the specialized tasks in photosynthesis, we aimed to optimize the efficiency of these processes separately, then combine them in an artificial photosynthesis (AP) process that surpasses the low efficiency of natural photosynthesis. Therefore, by combining photovoltaic light harvesting with electrolytic water splitting or CO2 reduction in combination with microbiological conversion of electrochemical products to higher valuable compounds, we developed an electro-microbial carbon capture and conversion setups that capture CO2 into the targeted bioplastic; polyhydroxybutyrate (PHB). Based on the type of the electrochemical products, and the microorganism that either (i) convert products formed by electrochemical reduction of CO2, e.g. formate (using inorganic cathodes), or (ii) use electrochemically produced H2 to reduce CO2

  10. Microbial hazards reduction during creamy cream cheese production

    Directory of Open Access Journals (Sweden)

    Dorota Miarka

    2015-03-01

    Full Text Available The purpose of the work was to identify the hazards relevant to the production of safe food and to assess the effects of a possible infection. The paper presents the microbiological hazards that can occur throughout the production of creamy cream cheese and indicates the means to their minimization or elimination. The analysis of microbiological hazards showed that in the manufacturing process of the type of cheese mentioned, there are a few critical steps that should be specifically overseen. In order to acquire a high quality product it is important to monitor a quality of raw material, the parameters of pasteurization and souring, temperature of product packaging, storage conditions of the finished product and maintain hygiene throughout the production. The process of heat treatment, which is pasteurization, is a critical step (critical control points - CCP for the whole process. Monitoring this stage and consistent adherence to Operational Pre-Condition Programs at the thermisation and centrifuging and later packaging, guarantees a safe product and its long shelf life.

  11. Intestinal intraepithelial lymphocyte-enterocyte crosstalk regulates production of bactericidal angiogenin 4 by Paneth cells upon microbial challenge.

    Directory of Open Access Journals (Sweden)

    Catherine R Walker

    Full Text Available Antimicrobial proteins influence intestinal microbial ecology and limit proliferation of pathogens, yet the regulation of their expression has only been partially elucidated. Here, we have identified a putative pathway involving epithelial cells and intestinal intraepithelial lymphocytes (iIELs that leads to antimicrobial protein (AMP production by Paneth cells. Mice lacking γδ iIELs (TCRδ(-/- express significantly reduced levels of the AMP angiogenin 4 (Ang4. These mice were also unable to up-regulate Ang4 production following oral challenge by Salmonella, leading to higher levels of mucosal invasion compared to their wild type counterparts during the first 2 hours post-challenge. The transfer of γδ iIELs from wild type (WT mice to TCRδ(-/- mice restored Ang4 production and Salmonella invasion levels were reduced to those obtained in WT mice. The ability to restore Ang4 production in TCRδ(-/- mice was shown to be restricted to γδ iIELs expressing Vγ7-encoded TCRs. Using a novel intestinal crypt co-culture system we identified a putative pathway of Ang4 production initiated by exposure to Salmonella, intestinal commensals or microbial antigens that induced intestinal epithelial cells to produce cytokines including IL‑23 in a TLR-mediated manner. Exposure of TCR-Vγ7(+ γδ iIELs to IL-23 promoted IL‑22 production, which triggered Paneth cells to secrete Ang4. These findings identify a novel role for γδ iIELs in mucosal defence through sensing immediate epithelial cell cytokine responses and influencing AMP production. This in turn can contribute to the maintenance of intestinal microbial homeostasis and epithelial barrier function, and limit pathogen invasion.

  12. Relationships among gas production, end products of rumen fermentation and microbial N produced in vitro at two incubation times

    DEFF Research Database (Denmark)

    Cattani, Mirko; Maccarana, Laura; Hansen, Hanne Helene

    2013-01-01

    at 48 h. At t½, the valerate content in rumen fl uid was negligible. However, relatively large amounts of valerate were measured after 48 h, probably the result of microbial lysis. Results suggest that relationships among end-products of rumen fermentation can be more accurately evaluated at a substrate...... for ammonia N (N-NH3), volatile fatty acids (VFA), residual NDF and N bound to residual NDF (N-NDF). Values of GP were also predicted from VFA. Microbial N (MN) was computed as the difference between N present at the beginning and at the end of incubation. At 48 h, the relationship between GP measured...

  13. Importance of systems biology in engineering microbes for biofuel production

    Energy Technology Data Exchange (ETDEWEB)

    Mukhopadhyay, Aindrila; Redding, Alyssa M.; Rutherford, Becky J.; Keasling, Jay D.

    2009-12-02

    Microorganisms have been rich sources for natural products, some of which have found use as fuels, commodity chemicals, specialty chemicals, polymers, and drugs, to name a few. The recent interest in production of transportation fuels from renewable resources has catalyzed numerous research endeavors that focus on developing microbial systems for production of such natural products. Eliminating bottlenecks in microbial metabolic pathways and alleviating the stresses due to production of these chemicals are crucial in the generation of robust and efficient production hosts. The use of systems-level studies makes it possible to comprehensively understand the impact of pathway engineering within the context of the entire host metabolism, to diagnose stresses due to product synthesis, and provides the rationale to cost-effectively engineer optimal industrial microorganisms.

  14. COMBINED MICROBIAL SURFACTANT-POLYMER SYSTEM FOR IMPROVED OIL MOBILITY AND CONFORMANCE CONTROL

    Energy Technology Data Exchange (ETDEWEB)

    Jorge Gabitto; Maria Barrufet

    2005-08-01

    Many domestic oil fields are facing abandonment even though they still contain two-thirds of their original oil. A significant number of these fields can yield additional oil using advanced oil recovery (AOR) technologies. To maintain domestic oil production at current levels, AOR technologies are needed that are affordable and can be implemented by the independent oil producers of the future. Microbial enhanced oil recovery (MEOR) technologies have become established as cost-effective solutions for declining oil production. MEOR technologies are affordable for independent producers operating stripper wells and can be used to extend the life of marginal fields. The demonstrated versatility of microorganisms can be used to design advanced microbial systems to treat multiple production problems in complex, heterogeneous reservoirs. The proposed research presents the concept of a combined microbial surfactant-polymer system for advanced oil recovery. The surfactant-polymer system utilizes bacteria that are capable of both biosurfactant production and metabolically-controlled biopolymer production. This novel technology combines complementary mechanisms to extend the life of marginal fields and is applicable to a large number of domestic reservoirs. The research project described in this report was performed by Bio-Engineering Inc., a woman owned small business, Texas A&M University and Prairie View A&M University, a Historically Black College and University. This report describes the results of our laboratory work to grow microbial cultures, the work done on recovery experiments on core rocks, and computer simulations. We have selected two bacterial strains capable of producing both surfactant and polymers. We have conducted laboratory experiments to determine under what conditions surfactants and polymers can be produced from one single strain. We have conduct recovery experiments to determine the performance of these strains under different conditions. Our results

  15. Electron acceptor-based regulation of microbial greenhouse gas production from thawing permafrost

    DEFF Research Database (Denmark)

    Bak, Ebbe Norskov; Jones, Eleanor; Yde, Jacob Clement

    layer as well in the permafrost. These investigations are accompanied by characterization of the carbon, iron and sulfate content in the soil and will be followed by characterization of the microbial community structure. The aim of this study is to get a better understanding of how the availability...... of sulfate and iron and the microbial community structure regulate the production of CO2 and CH4 in thawing permafrost, and to elucidate how the rate of the organic carbon degradation changes with depth in permafrost-affected soils. This study improves our understanding of climate feedback mechanisms...

  16. Microbial and heavy metal contamination of pineapple products ...

    African Journals Online (AJOL)

    SAM

    Quantitative determination of heavy metals: zinc, iron, lead, copper, cadmium and aluminium ...... consumption of dairy products, fish/seafood and meat from Ismailia ... Contamination in Green Leafy Vegetables Grown in Bangalore Urban.

  17. bioelectricity production from cassava mill effluents using microbial

    African Journals Online (AJOL)

    user

    2016-04-02

    Apr 2, 2016 ... technologies of energy production using renewable ... mediators in the commercial use of MFCs for energy .... gas for a period of 4 minutes to maintain anaerobic ..... potentials of some Nigerian industrial wastewater through ...

  18. Tibia mineralization of chickens determined to meat production using a microbial phytase

    Directory of Open Access Journals (Sweden)

    Mária Angelovičová

    2018-02-01

    Full Text Available The target of the research was 6-phytase of microbial origin. It was used in feed mixtures for chickens determined to meat production. Its effect has been studied in relation to the tibia mineralization by calcium, phosphorus and magnesium. 6-phytase is a product of Aspergillus oryzae. That was obtained by means of biotechnological processes of production of commercially available enzymes. It was incorporated in the feed mixtures 0.1%. In a 38-day feeding trial, 300 one-day-old, as hatched, Cobb 500 chickens determined to meat production (100 birds per group were fed on one concentrations of dietary non-phytate phosphorus (2.32, 2.31 g.kg-1, respectively and supplemental microbial phytase (0 and 500   FTU.kg-1 feed mixtures. Control group was used to compare the results and control feed mixtures contained 4.5 g.kg-1 without microbial phytase. At days 40 it was selected 6 birds in every group, which were slaughter in accordance with the principles of welfare. Left tibias of every bird were used to determination of calcium, phosphorus and magnesium contents. According to in vivo, it was found that the addition of microbial phytase to reduced dietary non-phytate phosphorus increased concentrations of calcium (Ca, phosphorus (P and magnesium (Mg in tibia. The differences among groups were statistically significant (p <0.05. It was concluded that reducing of dietary non-phytate phosphorus on the 2.32, 2.31 g.kg-1, respectively, by monocalcium phosphate and microbial phytase supplementation in feed mixtures facilitated tibia mineralization at chicken determined to meat production. Normal 0 21 false false false EN-GB X-NONE X-NONE

  19. Application of agave subproducts for production of microbial inulinases

    Directory of Open Access Journals (Sweden)

    Huerta Alcocer, S.A.

    2014-07-01

    Full Text Available Mexico is the center of origin of the genus Agave spp. with 159 endemic species, 75 % of all known species. The main use of these plants is in the production of alcoholic beverages, mainly tequila, which is obtained from the “pines” of A. tequilana Weber var. Azul. During tequila production, a huge amount of waste is produced, including leaves that are not used. Main compounds found in these subproducts are polysaccharides, specifically inulin. Current review focuses on the use of these agricultural wastes to obtain inulinase production, and in the production of high fructose syrup using these enzymes in these wastes. Currently, high fructose syrups, especially oligosaccharides, have prompted much interest for their benefits to health due to its low glycemic index and their function as prebiotic in the intestinal flora. The main microorganisms involved with inulinases production belong to the genera Aspergillus and Kluyveromyces. The latter is preferred in the industry due to its high growth rate, high temperature tolerance (52 °C and by having the GRAS (Generally Recognized As Safe status. This review emphasizes on the advances achieved in the production of inulinases by yeast K. marxianus.

  20. Gas production, microbial synthesis by radio phosphorus and digestibility of babassu and mofumbo in sheep diets

    International Nuclear Information System (INIS)

    Abdalla Filho, Adibe Luiz

    2015-01-01

    When food shortages in natural pastures is committed to animal nutrition, small ruminants can incorporate into their diets the leaves of other plants, such as trees and shrubs, many of them rich in secondary metabolites such as tannins and which still lack of studies about its effect on animal productivity. In order to verify the possibility of using leaves of Orbignya phalerata (Babassu) and Combretum leprosum (Mofumbo) in feed and to evaluate the effect of their inclusion in the sheep production system, two studies were conducted at the Animal Nutrition Laboratory of Centro de Energia Nuclear na Agricultura, Universidade de Sao Paulo, Piracicaba (LANA/CENA-USP). The first study evaluated the performance variables, biochemical and hematological parameters and also determined the microbial protein synthesis, nutrient apparent digestibility and enteric production of methane (CH4). The second study assessed the carcass characteristics, fatty acid profile and meat color of male sheep used in the first study. The experimental treatments were diets with forages to concentrate rate of 50:50, drawn up on the basis of using the leaves of the experimental plants replacing 30% of the Cynodon dactylon (Tifton-85) hay, resulting in three treatments: Control (no hay replacement), Babassu and Mofumbo. In the first study, there were used 24 Santa Ines sheep, in a randomized experimental design with eight repetitions for each treatment and 48 days of trial period. Also during this period, an in vitro microbial protein synthesis was performed using the radio phosphorus using five different inoculum of each studied treatment. After this period, for nine days, six animals from each treatment were allocated in metabolic cages for determining the nutrient apparent digestibility, microbial protein synthesis and nitrogen balance. Simultaneously it was quantified the enteric CH4 production in vivo. The Control group showed greater (P < 0.05) apparent digestibility of acid detergent fiber

  1. Assessing the impact of rumen microbial communities on methane emissions and production traits in Holstein cows in a tropical climate.

    Science.gov (United States)

    Cunha, Camila S; Veloso, Cristina M; Marcondes, Marcos I; Mantovani, Hilario C; Tomich, Thierry R; Pereira, Luiz Gustavo R; Ferreira, Matheus F L; Dill-McFarland, Kimberly A; Suen, Garret

    2017-12-01

    The evaluation of how the gut microbiota affects both methane emissions and animal production is necessary in order to achieve methane mitigation without production losses. Toward this goal, the aim of this study was to correlate the rumen microbial communities (bacteria, archaea, and fungi) of high (HP), medium (MP), and low milk producing (LP), as well as dry (DC), Holstein dairy cows in an actual tropical production system with methane emissions and animal production traits. Overall, DC cows emitted more methane, followed by MP, HP and LP cows, although HP and LP cow emissions were similar. Using next-generation sequencing, it was found that bacteria affiliated with Christensenellaceae, Mogibacteriaceae, S24-7, Butyrivibrio, Schwartzia, and Treponema were negatively correlated with methane emissions and showed positive correlations with digestible dry matter intake (dDMI) and digestible organic matter intake (dOMI). Similar findings were observed for archaea in the genus Methanosphaera. The bacterial groups Coriobacteriaceae, RFP12, and Clostridium were negatively correlated with methane, but did not correlate with dDMI and dOMI. For anaerobic fungal communities, no significant correlations with methane or animal production traits were found. Based on these findings, it is suggested that manipulation of the abundances of these microbial taxa may be useful for modulating methane emissions without negatively affecting animal production. Copyright © 2017 Elsevier GmbH. All rights reserved.

  2. Beneficial and Harmful Interactions of Antibiotics with Microbial Pathogens and the Host Innate Immune System

    Directory of Open Access Journals (Sweden)

    Ronald Anderson

    2010-05-01

    Full Text Available In general antibiotics interact cooperatively with host defences, weakening and decreasing the virulence of microbial pathogens, thereby increasing vulnerability to phagocytosis and eradication by the intrinsic antimicrobial systems of the host. Antibiotics, however, also interact with host defences by several other mechanisms, some harmful, others beneficial. Harmful activities include exacerbation of potentially damaging inflammatory responses, a property of cell-wall targeted agents, which promotes the release of pro-inflammatory microbial cytotoxins and cell-wall components. On the other hand, inhibitors of bacterial protein synthesis, especially macrolides, possess beneficial anti-inflammatory/cytoprotective activities, which result from interference with the production of microbial virulence factors/cytotoxins. In addition to these pathogen-directed, anti-inflammatory activities, some classes of antimicrobial agent possess secondary anti-inflammatory properties, unrelated to their conventional antimicrobial activities, which target cells of the innate immune system, particularly neutrophils. This is a relatively uncommon, potentially beneficial property of antibiotics, which has been described for macrolides, imidazole anti-mycotics, fluoroquinolones, and tetracyclines. Although of largely unproven significance in the clinical setting, increasing awareness of the pro-inflammatory and anti-inflammatory properties of antibiotics may contribute to a more discerning and effective use of these agents.

  3. Energy landscapes shape microbial communities in hydrothermal systems on the Arctic Mid-Ocean Ridge

    OpenAIRE

    Dahle, H?kon; ?kland, Ingeborg; Thorseth, Ingunn H; Pederesen, Rolf B; Steen, Ida H

    2015-01-01

    Methods developed in geochemical modelling combined with recent advances in molecular microbial ecology provide new opportunities to explore how microbial communities are shaped by their chemical surroundings. Here, we present a framework for analyses of how chemical energy availability shape chemotrophic microbial communities in hydrothermal systems through an investigation of two geochemically different basalt-hosted hydrothermal systems on the Arctic Mid-Ocean Ridge: the Soria Moria Vent f...

  4. Microbial Community Pathways for the Production of Volatile Fatty Acids From CO2 and Electricity

    Directory of Open Access Journals (Sweden)

    Jorge Wenzel

    2018-04-01

    Full Text Available This study aims at elucidating the metabolic pathways involved in the production of volatile fatty acids from CO2 and electricity. Two bioelectrochemical systems (BES were fed with pure CO2 (cells A and B. The cathode potential was first poised at −574 mV vs. standard hydrogen electrode (SHE and then at −756 mV vs. SHE in order to ensure the required reducing power. Despite applying similar operation conditions to both BES, they responded differently. A mixture of organic compounds (1.87 mM acetic acid, 2.30 mM formic acid, 0.43 mM propionic acid, 0.15 mM butyric acid, 0.55 mM valeric acid, and 0.62 mM ethanol was produced in cell A while mainly 1.82 mM acetic acid and 0.23 mM propionic acid were produced in cell B. The microbial community analysis performed by 16S rRNA gene pyrosequencing showed a predominance of Clostridium sp. and Serratia sp. in cell A whereas Burkholderia sp. and Xanthobacter sp. predominated in cell B. The coexistence of three metabolic pathways involved in carbon fixation was predicted. Calvin cycle was predicted in both cells during the whole experiment while Wood-Ljungdahl and Arnon-Buchanan pathways predominated in the period with higher coulombic efficiency. Metabolic pathways which transform organic acids into anabolic intermediaries were also predicted, indicating the occurrence of complex trophic interactions. These results further complicate the understanding of these mixed culture microbial processes but also expand the expectation of compounds that could potentially be produced with this technology.

  5. Research Progress of Hydrogen Production fromOrganic Wastes in Microbial Electrolysis Cell(MEC

    Directory of Open Access Journals (Sweden)

    YU Yin-sheng

    2015-08-01

    Full Text Available Microbial electrolysis cell(MECtechnology as an emerging technology, has achieved the target of hydrogen production from different substrates such as waste water, forestry wastes, activated sludge by simultaneous enzymolysis and fermentation, which can effectively improve the efficiency of resource utilization. This paper described the working principle of MEC and analyzed these factors influencing the process of hydrogen production from organic waste in MEC.

  6. Tracing the long-term microbial production of recalcitrant fluorescent dissolved organic matter in seawater

    DEFF Research Database (Denmark)

    Jørgensen, Linda; Stedmon, Colin A.; Granskog, Mats A.

    2014-01-01

    The majority of dissolved organic matter (DOM) in the ocean is resistant to microbial degradation, yet its formation remains poorly understood. The fluorescent fraction of DOM can be used to trace the formation of recalcitrant DOM (RDOM). A long-term (> 1 year) experiment revealed 27–52% removal...... of dissolved organic carbon and a nonlinear increase in RDOM fluorescence associated with microbial turnover of semilabile DOM. This fluorescence was also produced using glucose as the only initial carbon source, suggesting that degradation of prokaryote remnants contributes to RDOM. Our results indicate...... that the formation of a fluorescent RDOM component depends on the bioavailability of the substrate: the less labile, the larger the production of fluorescent RDOM relative to organic carbon remineralized. The anticipated increase in microbial carbon demand due to ocean warming can potentially forcemicrobes...

  7. Microbial community structures in high rate algae ponds for bioconversion of agricultural wastes from livestock industry for feed production.

    Science.gov (United States)

    Mark Ibekwe, A; Murinda, Shelton E; Murry, Marcia A; Schwartz, Gregory; Lundquist, Trygve

    2017-02-15

    Dynamics of seasonal microbial community compositions in algae cultivation ponds are complex. However, there is very limited knowledge on bacterial communities that may play significant roles with algae in the bioconversion of manure nutrients to animal feed. In this study, water samples were collected during winter, spring, summer, and fall from the dairy lagoon effluent (DLE), high rate algae ponds (HRAP) that were fed with diluted DLE, and municipal waste water treatment plant (WWTP) effluent which was included as a comparison system for the analysis of total bacteria, Cyanobacteria, and microalgae communities using MiSeq Illumina sequencing targeting the 16S V4 rDNA region. The main objective was to examine dynamics in microbial community composition in the HRAP used for the production of algal biomass. DNA was extracted from the different sample types using three commercially available DNA extraction kits; MoBio Power water extraction kit, Zymo fungi/bacterial extraction kit, and MP Biomedicals FastDNA SPIN Kit. Permutational analysis of variance (PERMANOVA) using distance matrices on each variable showed significant differences (P=0.001) in beta-diversity based on sample source. Environmental variables such as hydraulic retention time (HRT; P<0.031), total N (P<0.002), total inorganic N (P<0.002), total P (P<0.002), alkalinity (P<0.002), pH (P<0.022), total suspended solid (TSS; P<0.003), and volatile suspended solids (VSS; P<0.002) significantly affected microbial communities in DLE, HRAP, and WWTP. Of the operational taxonomic units (OTUs) identified to phyla level, the dominant classes of bacteria identified were: Cyanobacteria, Alpha-, Beta-, Gamma-, Epsilon-, and Delta-proteobacteria, Bacteroidetes, Firmicutes, and Planctomycetes. Our data suggest that microbial communities were significantly affected in HRAP by different environmental variables, and care must be taken in extraction procedures when evaluating specific groups of microbial communities for

  8. Engineered microbes and methods for microbial oil production

    Energy Technology Data Exchange (ETDEWEB)

    Stephanopoulos, Gregory; Tai, Mitchell; Chakraborty, Sagar

    2018-01-09

    Some aspects of this invention provide engineered microbes for oil production. Methods for microbe engineering and for use of engineered microbes are also provided herein. In some embodiments, microbes are provided that are engineered to modulate a combination of rate-controlling steps of lipid synthesis, for example, a combination of a step generating metabolites, acetyl-CoA, ATP or NADPH for lipid synthesis (a push step), and a step sequestering a product or an intermediate of a lipid synthesis pathway that mediates feedback inhibition of lipid synthesis (a pull step). Such push-and-pull engineered microbes exhibit greatly enhanced conversion yields and TAG synthesis and storage properties.

  9. Engineered microbes and methods for microbial oil production

    Science.gov (United States)

    Stephanopoulos, Gregory; Tai, Mitchell; Chakraborty, Sagar

    2015-02-10

    Some aspects of this invention provide engineered microbes for oil production. Methods for microbe engineering and for use of engineered microbes are also provided herein. In some embodiments, microbes are provided that are engineered to modulate a combination of rate-controlling steps of lipid synthesis, for example, a combination of a step generating metabolites, acetyl-CoA, ATP or NADPH for lipid synthesis (a push step), and a step sequestering a product or an intermediate of a lipid synthesis pathway that mediates feedback inhibition of lipid synthesis (a pull step). Such push-and-pull engineered microbes exhibit greatly enhanced conversion yields and TAG synthesis and storage properties.

  10. Primary productivity as a control over soil microbial diversity along environmental gradients in a polar desert ecosystem

    Directory of Open Access Journals (Sweden)

    Kevin M. Geyer

    2017-07-01

    Full Text Available Primary production is the fundamental source of energy to foodwebs and ecosystems, and is thus an important constraint on soil communities. This coupling is particularly evident in polar terrestrial ecosystems where biological diversity and activity is tightly constrained by edaphic gradients of productivity (e.g., soil moisture, organic carbon availability and geochemical severity (e.g., pH, electrical conductivity. In the McMurdo Dry Valleys of Antarctica, environmental gradients determine numerous properties of soil communities and yet relatively few estimates of gross or net primary productivity (GPP, NPP exist for this region. Here we describe a survey utilizing pulse amplitude modulation (PAM fluorometry to estimate rates of GPP across a broad environmental gradient along with belowground microbial diversity and decomposition. PAM estimates of GPP ranged from an average of 0.27 μmol O2/m2/s in the most arid soils to an average of 6.97 μmol O2/m2/s in the most productive soils, the latter equivalent to 217 g C/m2/y in annual NPP assuming a 60 day growing season. A diversity index of four carbon-acquiring enzyme activities also increased with soil productivity, suggesting that the diversity of organic substrates in mesic environments may be an additional driver of microbial diversity. Overall, soil productivity was a stronger predictor of microbial diversity and enzymatic activity than any estimate of geochemical severity. These results highlight the fundamental role of environmental gradients to control community diversity and the dynamics of ecosystem-scale carbon pools in arid systems.

  11. Hydrogen production with nickel powder cathode catalysts in microbial electrolysis cells

    KAUST Repository

    Selembo, Priscilla A.

    2010-01-01

    Although platinum is commonly used as catalyst on the cathode in microbial electrolysis cells (MEC), non-precious metal alternatives are needed to reduce costs. Cathodes were constructed using a nickel powder (0.5-1 μm) and their performance was compared to conventional electrodes containing Pt (0.002 μm) in MECs and electrochemical tests. The MEC performance in terms of coulombic efficiency, cathodic, hydrogen and energy recoveries were similar using Ni or Pt cathodes, although the maximum hydrogen production rate (Q) was slightly lower for Ni (Q = 1.2-1.3 m3 H2/m3/d; 0.6 V applied) than Pt (1.6 m3 H2/m3/d). Nickel dissolution was minimized by replacing medium in the reactor under anoxic conditions. The stability of the Ni particles was confirmed by examining the cathodes after 12 MEC cycles using scanning electron microscopy and linear sweep voltammetry. Analysis of the anodic communities in these reactors revealed dominant populations of Geobacter sulfurreduces and Pelobacter propionicus. These results demonstrate that nickel powder can be used as a viable alternative to Pt in MECs, allowing large scale production of cathodes with similar performance to systems that use precious metal catalysts. © 2009 Professor T. Nejat Veziroglu.

  12. A microbial fluidized electrode electrolysis cell (MFEEC) for enhanced hydrogen production

    KAUST Repository

    Liu, Jia

    2014-12-01

    A microbial fluidized electrode electrolysis cell (MFEEC) was used to enhance hydrogen gas production from dissolved organic matter. Flowable granular activated carbon (GAC) particles were used to provide additional surface area for growth of exoelectrogenic bacteria. The use of this exoelectrogenic biofilm on the GAC particles with fluidization produced higher current densities and hydrogen gas recoveries than controls (no recirculation or no GAC), due to intermittent contact of the capacitive particles with the anode. The total cumulative charge of 1688C m-2 with the MFEEC reactor (a recirculation flow rate of 19 mL min-1) was 20% higher than that of the control reactor (no GAC). The highest hydrogen gas yield of 0.82 ± 0.01 mol-H2/mol-acetate (17 mL min-1) was 39% higher than that obtained without recirculation (0.59 ± 0.01 mol-H 2/mol-acetate), and 116% higher than that of the control (no GAC, without recirculation). These results show that flowable GAC particles provide a useful approach for enhancing hydrogen gas production in bioelectrochemical systems. © 2014 Elsevier B.V. All rights reserved.

  13. High Acetic Acid Production Rate Obtained by Microbial Electrosynthesis from Carbon Dioxide.

    Science.gov (United States)

    Jourdin, Ludovic; Grieger, Timothy; Monetti, Juliette; Flexer, Victoria; Freguia, Stefano; Lu, Yang; Chen, Jun; Romano, Mark; Wallace, Gordon G; Keller, Jurg

    2015-11-17

    High product specificity and production rate are regarded as key success parameters for large-scale applicability of a (bio)chemical reaction technology. Here, we report a significant performance enhancement in acetate formation from CO2, reaching comparable productivity levels as in industrial fermentation processes (volumetric production rate and product yield). A biocathode current density of -102 ± 1 A m(-2) and an acetic acid production rate of 685 ± 30 (g m(-2) day(-1)) have been achieved in this study. High recoveries of 94 ± 2% of the CO2 supplied as the sole carbon source and 100 ± 4% of electrons into the final product (acetic acid) were achieved after development of a mature biofilm, reaching an elevated product titer of up to 11 g L(-1). This high product specificity is remarkable for mixed microbial cultures, which would make the product downstream processing easier and the technology more attractive. This performance enhancement was enabled through the combination of a well-acclimatized and enriched microbial culture (very fast start-up after culture transfer), coupled with the use of a newly synthesized electrode material, EPD-3D. The throwing power of the electrophoretic deposition technique, a method suitable for large-scale production, was harnessed to form multiwalled carbon nanotube coatings onto reticulated vitreous carbon to generate a hierarchical porous structure.

  14. Microbial production of the flavonoids garbanzol, resokaempferol and fisetin

    DEFF Research Database (Denmark)

    2016-01-01

    The invention provides a genetically modified micro-organism comprising one or more transgene for the production of one or more of the flavonoids garbanzol, resokaempferol and fisetin. The micro-organism may be a bacterial or yeast cell engineered to express a metabolic pathway for garbanzol...

  15. Microbial production of astilbin, a bioactive rhamnosylated flavanonol, from taxifolin

    DEFF Research Database (Denmark)

    Thuan, Nguyen Huy; Malla, Sailesh; Trung, Nguyen Thanh

    2017-01-01

    Flavonoids are plant-based polyphenolic biomolecules with a wide range of biological activities. Glycosylated flavonoids have drawn special attention in the industries as it improves solubility, stability, and bioactivity. Herein, we report the production of astilbin (ATN) from taxifolin (TFN) in...

  16. STRATEGIES FOR INCREASING PRODUCTIVITY IN PRODUCTION SYSTEMS

    Directory of Open Access Journals (Sweden)

    Diego Pacheco

    2014-05-01

    Full Text Available The main objective of this article is to point a set of practical strategies that can be adopted to increase the capacity of constraints resources on production systems, when the constraint is inside the factory and not is in the market. To serve this purpose will be presented strategies based on best practices of the Theory of Constraints, Lean Manufacturing and Total Productive Maintenance. This article also presents the mains tools for the deployment of these methodologies. The survey results have provided an objective set of practical strategy that can be used to increase the capacity and productivity of production systems according to the needs of each manufacturing system.

  17. Microbial production of next-generation stevia sweeteners.

    Science.gov (United States)

    Olsson, Kim; Carlsen, Simon; Semmler, Angelika; Simón, Ernesto; Mikkelsen, Michael Dalgaard; Møller, Birger Lindberg

    2016-12-07

    The glucosyltransferase UGT76G1 from Stevia rebaudiana is a chameleon enzyme in the targeted biosynthesis of the next-generation premium stevia sweeteners, rebaudioside D (Reb D) and rebaudioside M (Reb M). These steviol glucosides carry five and six glucose units, respectively, and have low sweetness thresholds, high maximum sweet intensities and exhibit a greatly reduced lingering bitter taste compared to stevioside and rebaudioside A, the most abundant steviol glucosides in the leaves of Stevia rebaudiana. In the metabolic glycosylation grid leading to production of Reb D and Reb M, UGT76G1 was found to catalyze eight different reactions all involving 1,3-glucosylation of steviol C 13 - and C 19 -bound glucoses. Four of these reactions lead to Reb D and Reb M while the other four result in formation of side-products unwanted for production. In this work, side-product formation was reduced by targeted optimization of UGT76G1 towards 1,3 glucosylation of steviol glucosides that are already 1,2-diglucosylated. The optimization of UGT76G1 was based on homology modelling, which enabled identification of key target amino acids present in the substrate-binding pocket. These residues were then subjected to site-saturation mutagenesis and a mutant library containing a total of 1748 UGT76G1 variants was screened for increased accumulation of Reb D or M, as well as for decreased accumulation of side-products. This screen was performed in a Saccharomyces cerevisiae strain expressing all enzymes in the rebaudioside biosynthesis pathway except for UGT76G1. Screening of the mutant library identified mutations with positive impact on the accumulation of Reb D and Reb M. The effect of the introduced mutations on other reactions in the metabolic grid was characterized. This screen made it possible to identify variants, such as UGT76G1 Thr146Gly and UGT76G1 His155Leu , which diminished accumulation of unwanted side-products and gave increased specific accumulation of the desired

  18. Production monitoring system for understanding product robustness

    DEFF Research Database (Denmark)

    Boorla, Srinivasa Murthy; Howard, Thomas J.

    2016-01-01

    study is used to demonstrate how the monitoring system can be used to efficiently guide corrective action to improve product performance. It is claimed that the monitoring system can be used to dramatically cut the time taken to identify, planand execute corrective action related to typical quality......In the current quality paradigm, the performance of a product is kept within specification by ensuring that its parts are within specification. Product performance is then validated after final assembly. However, this does not control how robust the product performance is, i.e. how much...... it will vary between the specification limits. In this paper, a model for predicting product performance is proposed, taking into account design, assembly and process parameters live from production. This empowers production to maintain final product performance, instead of part quality. The PRECI‐IN case...

  19. Microbial Cell Factories for the Production of Terpenoid Flavor and Fragrance Compounds.

    Science.gov (United States)

    Schempp, Florence M; Drummond, Laura; Buchhaupt, Markus; Schrader, Jens

    2018-03-14

    Terpenoid flavor and fragrance compounds are of high interest to the aroma industry. Microbial production offers an alternative sustainable access to the desired terpenoids independent of natural sources. Genetically engineered microorganisms can be used to synthesize terpenoids from cheap and renewable resources. Due to its modular architecture, terpenoid biosynthesis is especially well suited for the microbial cell factory concept: a platform host engineered for a high flux toward the central C 5 prenyl diphosphate precursors enables the production of a broad range of target terpenoids just by varying the pathway modules converting the C 5 intermediates to the product of interest. In this review typical terpenoid flavor and fragrance compounds marketed or under development by biotech and aroma companies are given, and the specificities of the aroma market are discussed. The main part of this work focuses on key strategies and recent advances to engineer microbes to become efficient terpenoid producers.

  20. Microbial Proteases in Baked Goods: Modification of Gluten and Effects on Immunogenicity and Product Quality

    Directory of Open Access Journals (Sweden)

    Nina G. Heredia-Sandoval

    2016-08-01

    Full Text Available Gluten-related diseases are a range of inflammatory disorders of the small intestine, characterized by an adverse response to gluten ingestion; therefore, the treatment is a gluten withdrawal. In spite of the increased market of gluten-free products, widely available breads with high acceptability are still missing due to the technological challenge of substituting the special gluten properties. Instead of using alternative ingredients for baking, some attempts have been done to decrease gluten immunogenicity by its enzymatic degradation with microbial proteases. Although the gluten immunogenicity reduction has been reached to an acceptable level, some quality parameters of the products are affected. This review focus on the use of microbial peptidases to prepare less immunogenic baked goods and their effect on product quality.

  1. Upgrading of straw hydrolysate for production of hydrogen and phenols in a microbial electrolysis cell (MEC)

    DEFF Research Database (Denmark)

    Thygesen, Anders; Marzorati, Massimo; Boon, Nico

    2011-01-01

    In a microbial electrolysis cell (MEC), hydrolysate produced by hydrothermal treatment of wheat straw was used for hydrogen production during selective recovery of phenols. The average H2 production rate was 0.61 m3 H2/m3 MEC·day and equivalent to a rate of 0.40 kg COD/m3 MEC·day. The microbial...... the energy content in the consumed compounds and the cell voltage of 0.7 V. The highest hydrogen production was equivalent to 0.8 kg COD/m3 MEC·day and was obtained at pH 7–8 and 25°C. Accumulation of 53% w/v phenolic compounds in the liquor was obtained by stepwise addition of the hydrolysate during...

  2. Microbial Proteases in Baked Goods: Modification of Gluten and Effects on Immunogenicity and Product Quality.

    Science.gov (United States)

    Heredia-Sandoval, Nina G; Valencia-Tapia, Maribel Y; Calderón de la Barca, Ana M; Islas-Rubio, Alma R

    2016-08-30

    Gluten-related diseases are a range of inflammatory disorders of the small intestine, characterized by an adverse response to gluten ingestion; therefore, the treatment is a gluten withdrawal. In spite of the increased market of gluten-free products, widely available breads with high acceptability are still missing due to the technological challenge of substituting the special gluten properties. Instead of using alternative ingredients for baking, some attempts have been done to decrease gluten immunogenicity by its enzymatic degradation with microbial proteases. Although the gluten immunogenicity reduction has been reached to an acceptable level, some quality parameters of the products are affected. This review focus on the use of microbial peptidases to prepare less immunogenic baked goods and their effect on product quality.

  3. Multi-electrode continuous flow microbial electrolysis cell for biogas production from acetate

    Energy Technology Data Exchange (ETDEWEB)

    Rader, Geoffrey K.; Logan, Bruce E. [Department of Civil and Environmental Engineering, Penn State University, University Park, PA 16802 (United States)

    2010-09-15

    Most microbial electrolysis cells (MECs) contain only a single set of electrodes. In order to examine the scalability of a multiple-electrode design, we constructed a 2.5 L MEC containing 8 separate electrode pairs made of graphite fiber brush anodes pre-acclimated for current generation using acetate, and 304 stainless steel mesh cathodes (64 m{sup 2}/m{sup 3}). Under continuous flow conditions and a one day hydraulic retention time, the maximum current was 181 mA (1.18 A/m{sup 2}, cathode surface area; 74 A/m{sup 3}) within three days of operation. The maximum hydrogen production (day 3) was 0.53 L/L-d, reaching an energy efficiency relative to electrical energy input of {eta}{sub E} = 144%. Current production remained relatively steady (days 3-18), but the gas composition dramatically shifted over time. By day 16, there was little H{sub 2} gas recovered and methane production increased from 0.049 L/L-d (day 3) to 0.118 L/L-d. When considering the energy value of both hydrogen and methane, efficiency relative to electrical input remained above 100% until near the end of the experiment (day 17) when only methane gas was being produced. Our results show that MECs can be scaled up primarily based on cathode surface area, but that hydrogen can be completely consumed in a continuous flow system unless methanogens can be completely eliminated from the system. (author)

  4. Multi-electrode continuous flow microbial electrolysis cell for biogas production from acetate

    KAUST Repository

    Rader, Geoffrey K.; Logan, Bruce E.

    2010-01-01

    Most microbial electrolysis cells (MECs) contain only a single set of electrodes. In order to examine the scalability of a multiple-electrode design, we constructed a 2.5 L MEC containing 8 separate electrode pairs made of graphite fiber brush anodes pre-acclimated for current generation using acetate, and 304 stainless steel mesh cathodes (64 m2/m3). Under continuous flow conditions and a one day hydraulic retention time, the maximum current was 181 mA (1.18 A/m2, cathode surface area; 74 A/m 3) within three days of operation. The maximum hydrogen production (day 3) was 0.53 L/L-d, reaching an energy efficiency relative to electrical energy input of ηE = 144%. Current production remained relatively steady (days 3-18), but the gas composition dramatically shifted over time. By day 16, there was little H2 gas recovered and methane production increased from 0.049 L/L-d (day 3) to 0.118 L/L-d. When considering the energy value of both hydrogen and methane, efficiency relative to electrical input remained above 100% until near the end of the experiment (day 17) when only methane gas was being produced. Our results show that MECs can be scaled up primarily based on cathode surface area, but that hydrogen can be completely consumed in a continuous flow system unless methanogens can be completely eliminated from the system. © 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.

  5. Multi-electrode continuous flow microbial electrolysis cell for biogas production from acetate

    KAUST Repository

    Rader, Geoffrey K.

    2010-09-01

    Most microbial electrolysis cells (MECs) contain only a single set of electrodes. In order to examine the scalability of a multiple-electrode design, we constructed a 2.5 L MEC containing 8 separate electrode pairs made of graphite fiber brush anodes pre-acclimated for current generation using acetate, and 304 stainless steel mesh cathodes (64 m2/m3). Under continuous flow conditions and a one day hydraulic retention time, the maximum current was 181 mA (1.18 A/m2, cathode surface area; 74 A/m 3) within three days of operation. The maximum hydrogen production (day 3) was 0.53 L/L-d, reaching an energy efficiency relative to electrical energy input of ηE = 144%. Current production remained relatively steady (days 3-18), but the gas composition dramatically shifted over time. By day 16, there was little H2 gas recovered and methane production increased from 0.049 L/L-d (day 3) to 0.118 L/L-d. When considering the energy value of both hydrogen and methane, efficiency relative to electrical input remained above 100% until near the end of the experiment (day 17) when only methane gas was being produced. Our results show that MECs can be scaled up primarily based on cathode surface area, but that hydrogen can be completely consumed in a continuous flow system unless methanogens can be completely eliminated from the system. © 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.

  6. Microbial alkaline proteases: Optimization of production parameters and their properties

    Directory of Open Access Journals (Sweden)

    Kanupriya Miglani Sharma

    2017-06-01

    Full Text Available Proteases are hydrolytic enzymes capable of degrading proteins into small peptides and amino acids. They account for nearly 60% of the total industrial enzyme market. Proteases are extensively exploited commercially, in food, pharmaceutical, leather and detergent industry. Given their potential use, there has been renewed interest in the discovery of proteases with novel properties and a constant thrust to optimize the enzyme production. This review summarizes a fraction of the enormous reports available on various aspects of alkaline proteases. Diverse sources for isolation of alkaline protease producing microorganisms are reported. The various nutritional and environmental parameters affecting the production of alkaline proteases in submerged and solid state fermentation are described. The enzymatic and physicochemical properties of alkaline proteases from several microorganisms are discussed which can help to identify enzymes with high activity and stability over extreme pH and temperature, so that they can be developed for industrial applications.

  7. Microbial production of next-generation stevia sweeteners

    DEFF Research Database (Denmark)

    Olsson, Kim; Carlsen, Simon; Semmler, Angelika

    2016-01-01

    BACKGROUND: The glucosyltransferase UGT76G1 from Stevia rebaudiana is a chameleon enzyme in the targeted biosynthesis of the next-generation premium stevia sweeteners, rebaudioside D (Reb D) and rebaudioside M (Reb M). These steviol glucosides carry five and six glucose units, respectively......, and have low sweetness thresholds, high maximum sweet intensities and exhibit a greatly reduced lingering bitter taste compared to stevioside and rebaudioside A, the most abundant steviol glucosides in the leaves of Stevia rebaudiana. RESULTS: In the metabolic glycosylation grid leading to production....... This screen made it possible to identify variants, such as UGT76G1Thr146Gly and UGT76G1His155Leu, which diminished accumulation of unwanted side-products and gave increased specific accumulation of the desired Reb D or Reb M sweeteners. This improvement in a key enzyme of the Stevia sweetener biosynthesis...

  8. Microbial production of the flavonoids garbanzol, resokaempferol and fisetin

    OpenAIRE

    Stahlhut, Steen Gustav; Siedler, Solvej; Neves, Ana Rute; MAURY,, JEROME; Förster, Jochen; Gaspar, Paula; Borodina, Irina; Rodriguez Prado, Edith Angelica; Strucko, Tomas

    2016-01-01

    The invention provides a genetically modified micro-organism comprising one or more transgene for the production of one or more of the flavonoids garbanzol, resokaempferol and fisetin. The micro-organism may be a bacterial or yeast cell engineered to express a metabolic pathway for garbanzol, resokaempferol and/or fisetin biosynthesis. The invention further provides a method for producing garbanzol, resokaempferol and/or fisetin employing the genetically modified micro-organism of the inventi...

  9. Chitin Lengthens Power Production in a Sedimentary Microbial Fuel Cell

    Science.gov (United States)

    2014-01-01

    organic carbon sediments demonstrate that chitin enhances and lengthens power production. Keywords—chitin; MFC; microbiology ; iron-reducing bacteria...levels of organic content available as a food source for bacteria in the sediment. Dependent upon applications, there are scenarios where a SMFC...as ethanol, molasses, or vegetable oils. In the case of underwater marine sediment, options for carbon amendment are limited to solid carbon

  10. Microbial production of hydrogen from starch-manufacturing wastes

    Energy Technology Data Exchange (ETDEWEB)

    Yokoi, H.; Maki, R.; Hirose, J.; Hayashi, S. [Miyazaki Univ. (Japan). Dept. of Applied Chemistry

    2002-05-01

    Effective hydrogen production from starch-manufacturing wastes by microorganisms was investigated. Continuous hydrogen production in high yield of 2.7 mol H{sub 2} mol{sup -1} glucose was attained by a mixed culture of Clostridium butyricum and Enterobacter aerogenes HO-39 in the starch waste medium consisting of sweet potato starch residue as a carbon source and corn steep liquor as a nitrogen source in a repeated batch culture. Rhodobacter sp. M-19 could produce hydrogen from the supernatant of the culture broth obtained in the repeated batch culture of C. butyricum and E. aerogenes HO-39. Hydrogen yield of 4.5 mol H{sub 2} mol{sup -1} glucose was obtained by culturing Rhodobacter sp. M-19 in the supernatant supplemented with 20{mu}gl{sup -1} Na{sub 2}MoO{sub 4} 2H{sub 2}O and 10mgl{sup -1} EDTA in a repeated batch culture with pH control at 7.5. Therefore, continuous hydrogen production with total hydrogen yield of 7.2 mol H{sub 2} mol{sup -1} glucose from the starch remaining in the starch residue was attained by the repeated batch culture with C. butyricum and E. aerogenes HO-39 and by the successive repeated batch culture with Rhodobacter sp. M-19. (Author)

  11. PRODUCTION AND USES OF MICROBIAL ENZYMES FOR DAIRY PROCESSING

    International Nuclear Information System (INIS)

    EL-KABBANY, H.M.I.

    2008-01-01

    The isolation and identification of fungal producer from various Egyptian dairy products samples was studied. Among fungi testes, only one out of the 48 isolates was found to be positive yielded a suitable enzyme substitute (rennet) and identified as Cryphonectria parasitica (C. parasitica) and was found to be negative for mycotoxins. The highest growth and production of the crude enzyme were obtained from barley medium after an incubation period for 6-8 days at 25 0 C and pH 5. It was found also to be sensitive to gamma rays, since 2.5 kGy completely inactivated the germination of the spores while very low doses up to 0.05 kGy did not affect the production of rennet like enzyme (RLE). Precipitation of the crude enzyme produced by C. parasitica using ammonium sulphate (NH 4 ) 2 SO 4 gave the highest milk clotting activity (MCA) at 50 0 C. Further purification was achieved by using Sephadex G-100 to give pure RLE. MCA of the fungal and animal rennin proved to be essentially identical in milk containing various concentrations of CaCl 2 . An addition of 160 ppm of CaCl 2 increased the enzyme activity. The optimum temperature was 60 0 C while pre-heating thermophiles at 15 0 C for 10 minutes complete inactivation. Both rennins manifested comparable clotting activities in milk at pH 6

  12. 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.

  13. Microbial pretreatment of corn stovers by solid-state cultivation of Phanerochaete chrysosporium for biogas production.

    Science.gov (United States)

    Liu, Shan; Wu, Shubiao; Pang, Changle; Li, Wei; Dong, Renjie

    2014-02-01

    The microbial pretreatment of corn stover and corn stover silage was achieved via the solid-state cultivation of Phanerochaete chrysosporium; pretreatment effects on the biodegradability and subsequent anaerobic production of biogas were investigated. The peak levels of daily biogas production and CH₄ yield from corn stover silage were approximately twice that of corn stover. Results suggested that ensiling was a potential pretreatment method to stimulate biogas production from corn stover. Surface morphology and Fourier-transform infrared spectroscopy analyses demonstrated that the microbial pretreatment of corn stover silage improved biogas production by 10.5 to 19.7% and CH4 yield by 11.7 to 21.2% because pretreatment could decrease dry mass loss (14.2%) and increase substrate biodegradability (19.9% cellulose, 32.4% hemicellulose, and 22.6% lignin). By contrast, the higher dry mass loss in corn stover (55.3%) after microbial pretreatment was accompanied by 54.7% cellulose, 64.0% hemicellulose, and 61.1% lignin degradation but did not significantly influence biogas production.

  14. Biodiesel biorefinery: opportunities and challenges for microbial production of fuels and chemicals from glycerol waste.

    Science.gov (United States)

    Almeida, João R M; Fávaro, Léia C L; Quirino, Betania F

    2012-07-18

    The considerable increase in biodiesel production worldwide in the last 5 years resulted in a stoichiometric increased coproduction of crude glycerol. As an excess of crude glycerol has been produced, its value on market was reduced and it is becoming a "waste-stream" instead of a valuable "coproduct". The development of biorefineries, i.e. production of chemicals and power integrated with conversion processes of biomass into biofuels, has been singled out as a way to achieve economically viable production chains, valorize residues and coproducts, and reduce industrial waste disposal. In this sense, several alternatives aimed at the use of crude glycerol to produce fuels and chemicals by microbial fermentation have been evaluated. This review summarizes different strategies employed to produce biofuels and chemicals (1,3-propanediol, 2,3-butanediol, ethanol, n-butanol, organic acids, polyols and others) by microbial fermentation of glycerol. Initially, the industrial use of each chemical is briefly presented; then we systematically summarize and discuss the different strategies to produce each chemical, including selection and genetic engineering of producers, and optimization of process conditions to improve yield and productivity. Finally, the impact of the developments obtained until now are placed in perspective and opportunities and challenges for using crude glycerol to the development of biodiesel-based biorefineries are considered. In conclusion, the microbial fermentation of glycerol represents a remarkable alternative to add value to the biodiesel production chain helping the development of biorefineries, which will allow this biofuel to be more competitive.

  15. Microbial and sponge loops modify fish production in phase-shifting coral reefs.

    Science.gov (United States)

    Silveira, Cynthia B; Silva-Lima, Arthur W; Francini-Filho, Ronaldo B; Marques, Jomar S M; Almeida, Marcelo G; Thompson, Cristiane C; Rezende, Carlos E; Paranhos, Rodolfo; Moura, Rodrigo L; Salomon, Paulo S; Thompson, Fabiano L

    2015-10-01

    Shifts from coral to algae dominance of corals reefs have been correlated to fish biomass loss and increased microbial metabolism. Here we investigated reef benthic and planktonic primary production, benthic dissolved organic carbon (DOC) release and bacterial growth efficiency in the Abrolhos Bank, South Atlantic. Benthic DOC release rates are higher while water column bacterial growth efficiency is lower at impacted reefs. A trophic model based on the benthic and planktonic primary production was able to predict the observed relative fish biomass in healthy reefs. In contrast, in impacted reefs, the observed omnivorous fish biomass is higher, while that of the herbivorous/coralivorous fish is lower than predicted by the primary production-based model. Incorporating recycling of benthic-derived carbon in the model through microbial and sponge loops explains the difference and predicts the relative fish biomass in both reef types. Increased benthic carbon release rates and bacterial carbon metabolism, but decreased bacterial growth efficiency could lead to carbon losses through respiration and account for the uncoupling of benthic and fish production in phase-shifting reefs. Carbon recycling by microbial and sponge loops seems to promote an increase of small-bodied fish productivity in phase-shifting coral reefs. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  16. Hydration interactions and stability of soluble microbial products in aqueous solutions.

    Science.gov (United States)

    Wang, Ling-Ling; Wang, Long-Fei; Ye, Xiao-Dong; Yu, Han-Qing

    2013-10-01

    Soluble microbial products (SMP) are organic compounds excreted by microorganisms in their metabolism and decay and the main constituents in effluent from biological wastewater treatment systems. They also have an important contribution to the dissolved organic matters in natural aqueous systems. So far the interactions between SMP colloids have not been well explored. In this work, the interactions between SMP colloids in water and salt solutions were studied by using a combination of static and dynamic light scattering, Fourier transform infrared spectra, Zeta potential and acid-base titration techniques. The second osmotic virial coefficient had a larger value in a 750-mM salt solution than that in a 50-mM solution, indicating that repulsion between SMP colloids increased with an increase in salt concentration, which is contrary with the classic Derjaguin, Landau, Verwey, and Overbeek (DLVO) theory. Such a repulsion was attributed to water structuring and enhanced by the accumulation of hydrophilic counter ions around SMP colloids and the formed hydration force. The repulsion and hydration effect led to the dispersing and deeper draining structure, accompanied by a decreased hydrodynamic radius and increased diffusion coefficient. This hydration force was related to so-called ion specific effect, and electrolyte sodium chloride had a more substantial effect on hydration force than KCl, CsCl, NaBr and NaI. Our results provide an experimental approach to explore the SMP structures, inter-colloid interactions and confirm the non-DLVO forces. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. AN EXPERIENCE OF HANDLING MICROBIAL CONTAMINATION OF PRODUCT WATER AT A HAEMODIALYSIS UNIT IN NORTH KARNATAKA OF INDIA

    Directory of Open Access Journals (Sweden)

    Archana Aravindrao Dambal

    2017-09-01

    Full Text Available BACKGROUND Dialysis units need regular prophylactic disinfection of the dialysis water production and distribution circuit without which there can be chronic inflammation among patients using the facility. The aim of the study is to present here our experience in containing an episode of microbial contamination of dialysis water. MATERIALS AND METHODS Our haemodialysis unit had a single pass reverse osmosis plant with facility for pretreatment of raw water and a distribution loop of medical grade PVC (polyvinyl chloride feeding haemodialysis machines, bicarbonate preparation and dialyser reprocessing areas. After installation, the Reverse Osmosis (RO membranes and distribution loop were disinfected every fortnight using formalin. Cultures of product water were sent from various sites in the product water loop every month. RESULTS From January to April 2011, 15 water samples out of 52 water samples grew Pseudomonas aeruginosa with a colony count over 200 Colony-Forming Units (CFU. The average monthly number of haemodialysis was reduced from 84.75 to 65. Two patients had intradialytic pyrexia and two others had mild lower respiratory infection. So, the reverse osmosis plant and product water distribution system were repeatedly disinfected using 2% formalin and 1% bleach ensuring contact time and thorough rinsing to address persistent cultures. When these measures could not eradicate microbial growth, the system was sanitised with Gramicid (48% w/w H2O2 + 500 ppm Ag and all traces of the disinfectant were rinsed away before resuming haemodialysis. CONCLUSION The microbial contamination of dialysis water was eradicated by Gramicid and not by bleach or formalin without any adverse effects after thorough rinsing.

  18. Critical control points for the management of microbial growth in HVAC systems

    NARCIS (Netherlands)

    Gommers, S; Franchimon, F.; Bronswijk, van J.E.M.H.; Strøm-Tejsen, P; Olesen, BW; Wargocki, P; Zukowska, D; Toftum, J

    2008-01-01

    Office buildings with HVAC systems consistently report Sick Building Symptoms that are derived from microbial growth. We used the HACCP methodology to find the main critical control points (CCPs) for microbial management of HVAC systems in temperate climates. Desk research revealed relative humidity

  19. Responses of Microbial Community Composition to Temperature Gradient and Carbon Steel Corrosion in Production Water of Petroleum Reservoir

    Directory of Open Access Journals (Sweden)

    Xiao-Xiao Li

    2017-12-01

    Full Text Available Oil reservoir production systems are usually associated with a temperature gradient and oil production facilities frequently suffer from pipeline corrosion failures. Both bacteria and archaea potentially contribute to biocorrosion of the oil production equipment. Here the response of microbial populations from the petroleum reservoir to temperature gradient and corrosion of carbon steel coupons were investigated under laboratory condition. Carbon steel coupons were exposed to production water from a depth of 1809 m of Jiangsu petroleum reservoir (China and incubated for periods of 160 and 300 days. The incubation temperatures were set at 37, 55, and 65°C to monitoring mesophilic, thermophilic and hyperthermophilic microorganisms associated with anaerobic carbon steel corrosion. The results showed that corrosion rate at 55°C (0.162 ± 0.013 mm year-1 and 37°C (0.138 ± 0.008 mm year-1 were higher than that at 65°C (0.105 ± 0.007 mm year-1, and a dense biofilm was observed on the surface of coupons under all biotic incubations. The microbial community analysis suggests a high frequency of bacterial taxa associated with families Porphyromonadaceae, Enterobacteriaceae, and Spirochaetaceae at all three temperatures. While the majority of known sulfate-reducing bacteria, in particular Desulfotignum, Desulfobulbus and Desulfovibrio spp., were predominantly observed at 37°C; Desulfotomaculum spp., Thermotoga spp. and Thermanaeromonas spp. as well as archaeal members closely related to Thermococcus and Archaeoglobus spp. were substantially enriched at 65°C. Hydrogenotrophic methanogens of the family Methanobacteriaceae were dominant at both 37 and 55°C; acetoclastic Methanosaeta spp. and methyltrophic Methanolobus spp. were enriched at 37°C. These observations show that temperature changes significantly alter the microbial community structure in production fluids and also affected the biocorrosion of carbon steel under anaerobic conditions.

  20. Defining product service systems

    DEFF Research Database (Denmark)

    McAloone, Timothy Charles; Andreasen, Mogens Myrup

    2002-01-01

    , company and society benefit from the service systems related to each one of these dimensions, rather than simply one of the above. There are existing examples of the enhancement of business and market share by focusing on PSS, but this is often not a result of upfront strategy and ambitious goals. We...... attempt to identify the nature of such a multiple definition of PSS, the link to proper understanding of value and utility and innovative approaches for PSS-oriented product development. This paper will expand on the phenomenon of PSS in the belief that a proper understanding of PSS will give us...

  1. Microbial spoilage, instability risk of antacid suspension in the presence of commonly used preservative system.

    Science.gov (United States)

    Khan, Jamshaid Ali; Khan, Imran Ullah; Iqbal, Zafar; Nasir, Fazli; Muhammad, Salar; Hannan, Peer Abdul; Ullah, Irfan

    2015-09-01

    Manifestation of microbial spoilage of any product by bacteria and to assess the effectiveness of the anti-microbial preservatives (parabens) used for the prevention and stability purpose. The aim of the present work is to study the effectiveness of preservatives used in the antacid suspensions and to analyze the effect of microbial growth on the quality of respective antacid suspensions. Samples of various antacid suspensions were randomly collected from local market and Government hospital pharmacies. Three different antacid formulations were prepared in the laboratory. All the formulations were preliminarily evaluated on the basis of organoleptic characteristics, pH, viscosity and assay. Efficacy of the preservative system in suspension formulation was determined by inoculating the samples in its final container, with specific strains of bacteria i.e. Escherichia coli ATCC 8739, Pseudomonas aeruginosa ATCC 9027 and Staphylococcus aureus ATCC 6538, taking samples from the inoculated preparation at specified intervals of time i.e. 0 time, 07 days, 14 days and 28 days, growing it on nutrient agar medium and colony forming units (CFUs) were scored by plate count. At the same time the samples were also subjected to qualitative and quantitative testing. The decrease in CFU and alteration in assay, pH and viscosity was observed in all the formulations except formulation M2 and F3 that showed stability throughout the study period.

  2. Microbial engineering for the production of advanced biofuels.

    Science.gov (United States)

    Peralta-Yahya, Pamela P; Zhang, Fuzhong; del Cardayre, Stephen B; Keasling, Jay D

    2012-08-16

    Advanced biofuels produced by microorganisms have similar properties to petroleum-based fuels, and can 'drop in' to the existing transportation infrastructure. However, producing these biofuels in yields high enough to be useful requires the engineering of the microorganism's metabolism. Such engineering is not based on just one specific feedstock or host organism. Data-driven and synthetic-biology approaches can be used to optimize both the host and pathways to maximize fuel production. Despite some success, challenges still need to be met to move advanced biofuels towards commercialization, and to compete with more conventional fuels.

  3. Kinetic Studies on Microbial Production of Tannase Using Redgram Husk

    OpenAIRE

    S. K. Mohan; T. Viruthagiri; C. Arunkumar

    2015-01-01

    Tannase (tannin acyl hydrolase, E.C.3.1.1.20) is an important hydrolysable enzyme with innumerable applications and industrial potential. In the present study, a kinetic model has been developed for the batch fermentation used for the production of tannase by A.flavus MTCC 3783. Maximum tannase activity of 143.30 U/ml was obtained at 96 hours under optimum operating conditions at 35oC, an initial pH of 5.5 and with an inducer tannic acid concentration of 3% (w/v) for a fe...

  4. Operational, design and microbial aspects related to power production with microbial fuel cells implemented in constructed wetlands.

    Science.gov (United States)

    Corbella, Clara; Guivernau, Miriam; Viñas, Marc; Puigagut, Jaume

    2015-11-01

    This work aimed at determining the amount of energy that can be harvested by implementing microbial fuel cells (MFC) in horizontal subsurface constructed wetlands (HSSF CWs) during the treatment of real domestic wastewater. To this aim, MFC were implemented in a pilot plant based on two HSSF CW, one fed with primary settled wastewater (Settler line) and the other fed with the effluent of a hydrolytic up-flow sludge blanket reactor (HUSB line). The eubacterial and archaeal community was profiled on wetland gravel, MFC electrodes and primary treated wastewater by means of 16S rRNA gene-based 454-pyrosequencing and qPCR of 16S rRNA and mcrA genes. Maximum current (219 mA/m(2)) and power (36 mW/m(2)) densities were obtained for the HUSB line. Power production pattern correlated well with water level fluctuations within the wetlands, whereas the type of primary treatment implemented had a significant impact on the diversity and relative abundance of eubacteria communities colonizing MFC. It is worth noticing the high predominance (13-16% of relative abundance) of one OTU belonging to Geobacter on active MFC of the HUSB line that was absent for the settler line MFC. Hence, MFC show promise for power production in constructed wetlands receiving the effluent of a HUSB reactor. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Plant, microbial and ecosystem carbon use efficiencies interact to stabilize microbial growth as a fraction of gross primary production.

    Science.gov (United States)

    Sinsabaugh, Robert L; Moorhead, Daryl L; Xu, Xiaofeng; Litvak, Marcy E

    2017-06-01

    The carbon use efficiency of plants (CUE a ) and microorganisms (CUE h ) determines rates of biomass turnover and soil carbon sequestration. We evaluated the hypothesis that CUE a and CUE h counterbalance at a large scale, stabilizing microbial growth (μ) as a fraction of gross primary production (GPP). Collating data from published studies, we correlated annual CUE a , estimated from satellite imagery, with locally determined soil CUE h for 100 globally distributed sites. Ecosystem CUE e , the ratio of net ecosystem production (NEP) to GPP, was estimated for each site using published models. At the ecosystem scale, CUE a and CUE h were inversely related. At the global scale, the apparent temperature sensitivity of CUE h with respect to mean annual temperature (MAT) was similar for organic and mineral soils (0.029°C -1 ). CUE a and CUE e were inversely related to MAT, with apparent sensitivities of -0.009 and -0.032°C -1 , respectively. These trends constrain the ratio μ : GPP (= (CUE a  × CUE h )/(1 - CUE e )) with respect to MAT by counterbalancing the apparent temperature sensitivities of the component processes. At the ecosystem scale, the counterbalance is effected by modulating soil organic matter stocks. The results suggest that a μ : GPP value of c. 0.13 is a homeostatic steady state for ecosystem carbon fluxes at a large scale. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  6. A QRM Discussion of Microbial Contamination of Non-sterile Drug Products, Using FDA and EMA Warning Letters Recorded between 2008 and 2016.

    Science.gov (United States)

    Santos, Ana M C; Doria, Mara S; Meirinhos-Soares, Luís; Almeida, António J; Menezes, José C

    2018-01-01

    by numerous manufacturers, representing a major risk to patients. It is necessary to understand the microbial hazards involved in the manufacturing process and evaluate their impact on final product quality so that effective prevention strategies can be implemented. A risk-based classification of most likely root causes for microbial contamination found in the warning letters issued by the US Food and Drug Administration and the European Medicines Agency is proposed. To validate the likely root causes extracted from the warning letters, a subject matter expert panel made of several manufacturers was formed and consulted. A quality risk management approach to assess microbiological contamination of non-sterile drug products is proposed for the identification of microbial hazards involved in the manufacturing process. To enable ranking of microbial contamination risks, quality risk management metrics related to criticality and overall risk were applied. The results showed that manufacturers of non-sterile drug products should improve their microbial control strategy, with special attention to quality controls of raw materials, primary containers, and closures. Besides that, they should invest in a more robust quality system and culture. As a start, manufacturers may consider investigating their specific microbiological risks, adressing their sites' own microbial ecology, type of manufacturing processes, and dosage form characteristics, as these may lead to increased contamination risks. Authorities should allow and enforce innovative, more comprehensive, and more effective approaches to in-process contamination monitoring and controls. © PDA, Inc. 2018.

  7. Laccase: microbial sources, production, purification, and potential biotechnological applications.

    Science.gov (United States)

    Shraddha; Shekher, Ravi; Sehgal, Simran; Kamthania, Mohit; Kumar, Ajay

    2011-01-01

    Laccase belongs to the blue multicopper oxidases and participates in cross-linking of monomers, degradation of polymers, and ring cleavage of aromatic compounds. It is widely distributed in higher plants and fungi. It is present in Ascomycetes, Deuteromycetes and Basidiomycetes and abundant in lignin-degrading white-rot fungi. It is also used in the synthesis of organic substance, where typical substrates are amines and phenols, the reaction products are dimers and oligomers derived from the coupling of reactive radical intermediates. In the recent years, these enzymes have gained application in the field of textile, pulp and paper, and food industry. Recently, it is also used in the design of biosensors, biofuel cells, as a medical diagnostics tool and bioremediation agent to clean up herbicides, pesticides and certain explosives in soil. Laccases have received attention of researchers in the last few decades due to their ability to oxidize both phenolic and nonphenolic lignin-related compounds as well as highly recalcitrant environmental pollutants. It has been identified as the principal enzyme associated with cuticular hardening in insects. Two main forms have been found: laccase-1 and laccase-2. This paper reviews the occurrence, mode of action, general properties, production, applications, and immobilization of laccases within different industrial fields.

  8. Laccase: Microbial Sources, Production, Purification, and Potential Biotechnological Applications

    Directory of Open Access Journals (Sweden)

    Shraddha

    2011-01-01

    Full Text Available Laccase belongs to the blue multicopper oxidases and participates in cross-linking of monomers, degradation of polymers, and ring cleavage of aromatic compounds. It is widely distributed in higher plants and fungi. It is present in Ascomycetes, Deuteromycetes and Basidiomycetes and abundant in lignin-degrading white-rot fungi. It is also used in the synthesis of organic substance, where typical substrates are amines and phenols, the reaction products are dimers and oligomers derived from the coupling of reactive radical intermediates. In the recent years, these enzymes have gained application in the field of textile, pulp and paper, and food industry. Recently, it is also used in the design of biosensors, biofuel cells, as a medical diagnostics tool and bioremediation agent to clean up herbicides, pesticides and certain explosives in soil. Laccases have received attention of researchers in the last few decades due to their ability to oxidize both phenolic and nonphenolic lignin-related compounds as well as highly recalcitrant environmental pollutants. It has been identified as the principal enzyme associated with cuticular hardening in insects. Two main forms have been found: laccase-1 and laccase-2. This paper reviews the occurrence, mode of action, general properties, production, applications, and immobilization of laccases within different industrial fields.

  9. Pesticide Product Information System (PPIS)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Pesticide Product Information System contains information concerning all pesticide products registered in the United States. It includes registrant name and...

  10. Methodological approaches for studying the microbial ecology of drinking water distribution systems

    OpenAIRE

    Douterelo, Isabel; Boxall, Joby B.; Deines, Peter; Sekar, Raju; Fish, Katherine E.; Biggs, Catherine A.

    2014-01-01

    The study of the microbial ecology of drinking water distribution systems (DWDS) has traditionally been based on culturing organisms from bulk water samples. The development and application of molecular methods has supplied new tools for examining the microbial diversity and activity of environmental samples, yielding new insights into the microbial community and its diversity within these engineered ecosystems. In this review, the currently available methods and emerging approaches for chara...

  11. Evidence of microbial rhodopsins in Antarctic Dry Valley edaphic systems.

    Science.gov (United States)

    Guerrero, Leandro D; Vikram, Surendra; Makhalanyane, Thulani P; Cowan, Don A

    2017-09-01

    Microorganisms able to synthesize rhodopsins have the capacity to translocate ions through their membranes, using solar energy to generate a proton motive force. Rhodopsins are the most abundant phototrophic proteins in oceanic surface waters and are key constituents in marine bacterial ecology. However, it remains unclear how rhodopsins are used in most microorganisms. Despite their abundance in marine and fresh-water systems, the presence of functional rhodopsin systems in edaphic habitats has never been reported. Here, we show the presence of several new putative H + , Na + and Cl + pumping rhodopsins identified by metagenomic analysis of Antarctic desert hypolithic communities. Reconstruction of two Proteobacteria genomes harboring xanthorhodopsin-like proteins and one Bacteroidetes genome with a Na-pumping-like rhodopsin indicated that these bacteria were aerobic heterotrophs possessing the apparent capacity for the functional expression of rhodopsins. The existence of these protein systems in hypolithic bacteria expands the known role of rhodopsins to include terrestrial environments and suggests a possible predominant function as heterotrophic energy supply proteins, a feasible microbial adaptation to the harsh conditions prevalent in Antarctic edaphic systems. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  12. Microbial production of four biodegradable siderophores under submerged fermentation.

    Science.gov (United States)

    Fazary, Ahmed E; Al-Shihri, Ayed S; Alfaifi, Mohammad Y; Saleh, Kamel A; Alshehri, Mohammed A; Elbehairi, Serag Eldin I; Ju, Yi-Hsu

    2016-07-01

    Four siderophore analogues were isolated and purified from Escherichia coli, Bacillus spp. ST13, and Streptomyces pilosus microorganisms under some specific submerged fermentation conditions. In order to evaluate the highest production of this siderophore analogues through the growth, a rapid spectrophotometric screening semi-quantitative method was used, in which interestingly the analogues were isolated in its own form not its iron chelate. After chromatographic separation, the chemical structures of the isolated and purified siderophores were illustrated using detailed spectroscopic techniques. The biodegradation studies were done on that four novel isolated and purified siderophores following OECD protocols. In addition, the bioactivities of these siderophores and their iron complexes were examined and evaluated. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Soil biochemical properties and microbial resilience in agroforestry systems: effects on wheat growth under controlled drought and flooding conditions.

    Science.gov (United States)

    Rivest, David; Lorente, Miren; Olivier, Alain; Messier, Christian

    2013-10-01

    Agroforestry is increasingly viewed as an effective means of maintaining or even increasing crop and tree productivity under climate change while promoting other ecosystem functions and services. This study focused on soil biochemical properties and resilience following disturbance within agroforestry and conventional agricultural systems and aimed to determine whether soil differences in terms of these biochemical properties and resilience would subsequently affect crop productivity under extreme soil water conditions. Two research sites that had been established on agricultural land were selected for this study. The first site included an 18-year-old windbreak, while the second site consisted in an 8-year-old tree-based intercropping system. In each site, soil samples were used for the determination of soil nutrient availability, microbial dynamics and microbial resilience to different wetting-drying perturbations and for a greenhouse pot experiment with wheat. Drying and flooding were selected as water stress treatments and compared to a control. These treatments were initiated at the beginning of the wheat anthesis period and maintained over 10 days. Trees contributed to increase soil nutrient pools, as evidenced by the higher extractable-P (both sites), and the higher total N and mineralizable N (tree-based intercropping site) found in the agroforestry compared to the conventional agricultural system. Metabolic quotient (qCO2) was lower in the agroforestry than in the conventional agricultural system, suggesting higher microbial substrate use efficiency in agroforestry systems. Microbial resilience was higher in the agroforestry soils compared to soils from the conventional agricultural system (windbreak site only). At the windbreak site, wheat growing in soils from agroforestry system exhibited higher aboveground biomass and number of grains per spike than in conventional agricultural system soils in the three water stress treatments. At the tree

  14. Effects of copper particles on a model septic system's function and microbial community.

    Science.gov (United States)

    Taylor, Alicia A; Walker, Sharon L

    2016-03-15

    There is concern surrounding the addition of nanoparticles into consumer products due to toxicity potential and the increased risk of human and environmental exposures to these particles. Copper nanoparticles are found in many common consumer goods; therefore, the disposal and subsequent interactions between potentially toxic Cu-based nanoparticles and microbial communities may have detrimental impacts on wastewater treatment processes. This study investigates the effects of three copper particles (micron- and nano-scale Cu particles, and a nano-scale Cu(OH)2-based fungicide) on the function and operation of a model septic tank. Septic system analyses included water quality evaluations and microbial community characterizations to detect changes in and relationships between the septic tank function and microbial community phenotype/genotype. As would be expected for optimal wastewater treatment, biological oxygen demand (BOD5) was reduced by at least 63% during nano-scale Cu exposure, indicating normal function. pH was reduced to below the optimum anaerobic fermentation range during the micro Cu exposure, suggesting incomplete degradation of organic waste may have occurred. The copper fungicide, Cu(OH)2, caused a 57% increase in total organic carbon (TOC), which is well above the typical range for septic systems and also corresponded to increased BOD5 during the majority of the Cu(OH)2 exposure. The changes in TOC and BOD5 demonstrate that the system was improperly treating waste. Overall, results imply individual exposures to the three Cu particles caused distinct disruptions in septic tank function. However, it was observed that the system was able to recover to typical operating conditions after three weeks post-exposure. These results imply that during periods of Cu introduction, there are likely pulses of improper removal of total organic carbon and significant changes in pH not in the optimal range for the system. Copyright © 2016 Elsevier Ltd. All rights

  15. Optimizing Cofactor Specificity of Oxidoreductase Enzymes for the Generation of Microbial Production Strains—OptSwap

    DEFF Research Database (Denmark)

    King, Zachary A.; Feist, Adam

    2013-01-01

    Central oxidoreductase enzymes (eg, dehydrogenases, reductases) in microbial metabolism often have preferential binding specificity for one of the two major currency metabolites NAD(H) and NADP(H). These enzyme specificities result in a division of the metabolic functionality of the currency...... specificities of oxidoreductase enzyme and complementary reaction knockouts. Using the Escherichia coli genome-scale metabolic model iJO1366, OptSwap predicted eight growth-coupled production designs with significantly greater product yields or substrate-specific productivities than designs predicted with gene...

  16. Nanomodification of the electrodes in microbial fuel cell: impact of nanoparticle density on electricity production and microbial community

    DEFF Research Database (Denmark)

    Al Atraktchi, Fatima Al-Zahraa; Zhang, Yifeng; Angelidaki, Irini

    2014-01-01

    The nano-decoration of electrode with nanoparticles is one effective way to enhance power output of microbial fuel cells (MFCs). However, the amount of nanoparticles used for decoration has not been optimized yet, and how it affects the microbial community is still unknown. In this study, differe...

  17. 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.

  18. Microbial Diversity-Based Novel Crop Protection Products

    Energy Technology Data Exchange (ETDEWEB)

    Pioneer Hi-Bred International Inc.; DuPont Experimental Station; Yalpani, Ronald Flannagan, Rafael Herrmann, James Presnail, Tamas Torok, and Nasser; Herrmann, Rafael; Presnail, James; Torok, Tamas; Yalpani, Nasser

    2007-05-10

    Extremophilic microorganisms are adapted to survive in ecological niches with high temperatures, extremes of pH, high salt concentrations, high pressure, radiation, etc. Extremophiles produce unique biocatalysts and natural products that function under extreme conditions comparab le to those prevailing in various industrial processes. Therefore, there is burgeoning interest in bioprospecting for extremophiles with potential immediate use in agriculture, the food, chemical, and pharm aceutical industries, and environmental biotechnology. Over the years, several thousand extremophilic bacteria, archaea, and filamentous fungi were collected at extreme environmental sites in the USA, the Chernobyl Exclusion Zone surrounding the faeild nuclear power plant in Ukraine, in and around Lake Baikal in Siberia, and at geothermal sites on the Kamchatka peninsula in Russia. These organisms were cultured under proprietary conditions, and the cell- free supernatants were screened for biological activities against plant pathogenic fungi and major crop damaging insects. Promising peptide lead molecules were isolated, characterized, and sequenced. Relatively high hit rates characterized the tested fermentation broths. Of the 26,000 samples screened, over thousand contained biological activity of interest. A fair number of microorganisms expressed broad- spectrum antifungal or insecticidal activity. Two- dozen broadly antifungal peptides (AFPs) are alr eady patent protected, and many more tens are under further investigation. Tapping the gene pool of extremophilic microorganisms to provide novel ways of crop protection proved a successful strategy.

  19. Microbial Diversity-Based Novel Crop Protection Products

    International Nuclear Information System (INIS)

    Flannagan, Ronald; Herrmann, Rafael; Presnail, James; Torok, Tamas; Yalpani, Nasser

    2007-01-01

    Extremophilic microorganisms are adapted to survive in ecological niches with high temperatures, extremes of pH, high salt concentrations, high pressure, radiation, etc. Extremophiles produce unique biocatalysts and natural products that function under extreme conditions comparab le to those prevailing in various industrial processes. Therefore, there is burgeoning interest in bioprospecting for extremophiles with potential immediate use in agriculture, the food, chemical, and pharm aceutical industries, and environmental biotechnology. Over the years, several thousand extremophilic bacteria, archaea, and filamentous fungi were collected at extreme environmental sites in the USA, the Chernobyl Exclusion Zone surrounding the faeild nuclear power plant in Ukraine, in and around Lake Baikal in Siberia, and at geothermal sites on the Kamchatka peninsula in Russia. These organisms were cultured under proprietary conditions, and the cell- free supernatants were screened for biological activities against plant pathogenic fungi and major crop damaging insects. Promising peptide lead molecules were isolated, characterized, and sequenced. Relatively high hit rates characterized the tested fermentation broths. Of the 26,000 samples screened, over thousand contained biological activity of interest. A fair number of microorganisms expressed broad- spectrum antifungal or insecticidal activity. Two- dozen broadly antifungal peptides (AFPs) are alr eady patent protected, and many more tens are under further investigation. Tapping the gene pool of extremophilic microorganisms to provide novel ways of crop protection proved a successful strategy.

  20. Biotechnological strategies to improve production of microbial poly-(3-hydroxybutyrate): a review of recent research work.

    Science.gov (United States)

    Peña, C; Castillo, T; García, A; Millán, M; Segura, D

    2014-07-01

    Poly-(3-hydroxybutyrate) [P(3HB)] is a polyester synthesized as a carbon and energy reserve material by a wide number of bacteria. This polymer is characterized by its thermo-plastic properties similar to plastics derived from petrochemical industry, such as polyethylene and polypropylene. Furthermore, P(3HB) is an inert, biocompatible and biodegradable material which has been proposed for several uses in medical and biomedical areas. Currently, only few bacterial species such as Cupriavidus necator, Azohydromonas lata and recombinant Escherichia coli have been successfully used for P(3HB) production at industrial level. Nevertheless, in recent years, several fermentation strategies using other microbial models such as Azotobacter vinelandii, A. chroococcum, as well as some methane-utilizing species, have been developed in order to improve the P(3HB) production and also its mean molecular weight. © 2014 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  1. Production of microbial oil with high oleic acid content by Trichosporon capitatum

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Hong; Zong, Minhua [State Key Laboratory of Pulp and Paper Engineering, College of Light Industry and Food Sciences, South China University of Technology, Guangzhou 510640 (China); Li, Yuanyuan; Chen, Lei [School of Biosciences and Bioengineering, South China University of Technology, Guangzhou 510640 (China)

    2011-01-15

    Microbial oils with high unsaturated fatty acids content, especially oleic acid content, are good feedstock for high quality biodiesel production. Trichosporon capitatum was found to accumulate lipid with around 80% oleic acid and 89% total unsaturated fatty acids content on nitrogen-limited medium. In order to improve its lipid yield, effects of medium components and culture conditions on cell growth and lipid accumulation were investigated. Optimization of media resulted in a 61% increase in the lipid yield of T. capitatum after cultivation at 28 C and 160 rpm for 6 days. In addition, T. capitatum could grow well on cane molasses and afford a lipid yield comparable to that on synthetic nitrogen-limited medium. The biodiesel from the microbial oil produced by T. capitatum on cane molasses displayed a low cold filter plugging point (-15 C), and so T. capitatum might be a promising strain to provide lipid suitable for high quality biodiesel production. (author)

  2. Effect of warm-smoking on total microbial count of meat products

    Directory of Open Access Journals (Sweden)

    A Javadi

    2007-11-01

    Full Text Available The frankfurters are amongst the most famous and popular sausages in the world and beef and poultry meat are used in Iran for their preparation. The techniques of warm smoking at 42°c for two hours and then hot smoking together with steam cooking at 8°c for one hour are utilized in proportion of this product. In spite of its carcinogenic properties, smoke is used to create color, flavor and odor and to improve the preservative qualities of sausages. In this study, 14 sausage samples were taken from each of the stages of frankfurter production line including pre-smoking, post- warm smoking and post-hot smoking, their total microbial counts (aerobic mesophiles determined and the means of the three stages compared using the ANOVA statistical test. The results indicated that the total microbial count increased significantly (P

  3. An overview of aquatic photochemistry as it relates to microbial production

    Energy Technology Data Exchange (ETDEWEB)

    Miller, W.L. [Dalhousie Univ., Halifax, NS (Canada). Inst. of Oceanography

    2000-07-01

    A review of fundamental photochemistry and its potential impact on microbial processes in natural waters was presented. It is a known fact that solar radiation alters chromophoric dissolved organic matter (CDOM) and results in the production of a complex mixture of reactive oxygen species, inorganic nutrients, and carbon photoproducts. In addition, it results in reduced average molecular weight and changes in water optical properties. The largest carbon product results from the direct photo-mineralization of dissolved organic carbon (DOC) to dissolved inorganic carbon (DIC), thereby bypassing the microbial web. Other studies demonstrated that growth was enhanced for heterotrophic bacteria in natural samples exposed to sunlight, that bacterial growth was absent when stimulated by photochemistry and that there was a marked reduction in the ability of DOC to support bacterial growth after exposure to ultraviolet radiation B (UV-B). 20 refs., 1 fig.

  4. Biomethane production and microbial community response according to influent concentration of molasses wastewater in a UASB reactor.

    Science.gov (United States)

    Yun, Jeonghee; Lee, Sang Don; Cho, Kyung-Suk

    2016-05-01

    This study aimed to investigate the interaction between methane production performance and active microbial community dynamics at different loading rates by increasing influent substrate concentration. The model system was an upflow anaerobic sludge blanket (UASB) reactor using molasses wastewater. The active microbial community was analyzed using a ribosomal RNA-based approach in order to reflect active members in the UASB system. The methane production rate (MPR) increased with an increase in organic loading rate (OLR) from 3.6 to 5.5 g COD·L(-1)·day(-1) and then it decreased with further OLR addition until 9.7 g COD·L(-1)·day(-1). The UASB reactor achieved a maximum methane production rate of 0.48 L·L(-1)·day(-1) with a chemical oxygen demand (COD) removal efficiency of 91.2 % at an influent molasses concentration of 16 g COD·L(-1) (OLR of 5.5 g COD·L(-1)·day(-1)). In the archaeal community, Methanosarcina was predominant irrespective of loading rate, and the relative abundance of Methanosaeta increased with loading rate. In the bacterial community, Firmicutes and Eubacteriaceae were relatively abundant in the loading conditions tested. The network analysis between operation parameters and microbial community indicated that MPR was positively associated with most methanogenic archaea, including the relatively abundant Methanosarcina and Methanosaeta, except Methanofollis. The most abundant Methanosarcina was negatively associated with Bifidobacterium and Methanosaeta, whereas Methanosaeta was positively associated with Bifidobacterium.

  5. Methane Production in Microbial Reverse-Electrodialysis Methanogenesis Cells (MRMCs) Using Thermolytic Solutions

    KAUST Repository

    Luo, Xi

    2014-08-05

    The utilization of bioelectrochemical systems for methane production has attracted increasing attention, but producing methane in these systems requires additional voltage to overcome large cathode overpotentials. To eliminate the need for electrical grid energy, we constructed a microbial reverse- electrodialysis methanogenesis cell (MRMC) by placing a reverse electrodialysis (RED) stack between an anode with exoelectrogenic microorganisms and a methanogenic biocathode. In the MRMC, renewable salinity gradient energy was converted to electrical energy, thus providing the added potential needed for methane evolution from the cathode. The feasibility of the MRMC was examined using three different cathode materials (stainless steel mesh coated with platinum, SS/Pt; carbon cloth coated with carbon black, CC/CB; or a plain graphite fiber brush, GFB) and a thermolytic solution (ammonium bicarbonate) in the RED stack. A maximum methane yield of 0.60 ± 0.01 mol-CH 4/mol-acetate was obtained using the SS/Pt biocathode, with a Coulombic recovery of 75 ± 2% and energy efficiency of 7.0 ± 0.3%. The CC/CB biocathode MRMC had a lower methane yield of 0.55 ± 0.02 mol-CH4/mol-acetate, which was twice that of the GFB biocathode MRMC. COD removals (89-91%) and Coulombic efficiencies (74-81%) were similar for all cathode materials. Linear sweep voltammetry and electrochemical impedance spectroscopy tests demonstrated that cathodic microorganisms enhanced electron transfer from the cathode compared to abiotic controls. These results show that the MRMC has significant potential for production of nearly pure methane using low-grade waste heat and a source of waste organic matter at the anode. © 2014 American Chemical Society.

  6. Effects of nitrogen deposition and cattle grazing on productivity, invasion impact, and soil microbial processes in a serpentine grassland

    Science.gov (United States)

    Pasari, J.; Hernandez, D.; Selmants, P. C.; Keck, D.

    2010-12-01

    In recent decades, human activities have vastly increased the amount of biologically available nitrogen (N) in the biosphere. The resulting increase in N availability has broadly affected ecosystems through increased productivity, changes in species composition, altered nutrient cycles, and increases in invasion by exotic plant species, especially in systems that were historically low in N. California serpentine grasslands are N-limited ecosystems historically dominated by native species including several threatened and endangered plants and animals. Cattle grazing has emerged as the primary tool for controlling the impact of nitrophilic exotic grasses whose increased abundance has paralleled the regional traffic-derived increase in atmospheric N deposition. We examined the interactive effects of cattle grazing and N deposition on plant community composition, productivity, invasion resistance, and microbial processes in the Bay Area's largest serpentine grassland to determine the efficacy of current management strategies as well as the biogeochemical consequences of exotic species invasion. In the first two years of the study, aboveground net primary productivity decreased in response to grazing and increased in response to nitrogen addition. However, contrary to our hypotheses the change in productivity was not due to an increase in exotic species cover as there was little overall effect of grazing or N addition on species composition. Microbial activity was more responsive to grazing and N. Potential net N mineralization rates increased with N addition, but were not affected by grazing. In contrast, soil respiration rates were inhibited by grazing, but were not affected by N addition; suggesting strong carbon-limitation of soil microbial activity, particularly under grazing. Site differences in soil depth and grazing intensity were often more important than treatment effects. We suspect that the unusually dry conditions in the first two growing seasons inhibited

  7. Screening and Molecular Identification of New Microbial Strains for Production of Enzymes of Biotechnological Interest

    Directory of Open Access Journals (Sweden)

    Imen Ghazala

    Full Text Available ABSTRACT: This research focused on isolation, identification and characterization of new strains of fungi and bacteria, which were able to produce extracellular xylanase, mannanase, pectinase and α-amylase. Fungi isolates were identified on the basis of analyses of 18S gene sequencing and internal transcribed spacer region. The closest phylogenetic neighbors according to 18S gene sequence and ITS region data for the two isolates M1 and SE were Aspergillus fumigatus and Aspergillus sydowii, respectively. I4 was identified as Bacillus mojavensis on the basis of the 16S rRNA gene sequencing and biochemical properties. The enzyme production was evaluated by cultivating the isolated microorganisms in liquid-state bioprocess using wheat bran as carbon source. Two fungi (M1, and SE and one bacterium (I4 strains were found to be xylanase producer, and several were proven to be outstanding producers of microbial xylanase. The strains producing xylanase secreted variable amounts of starch-debranching enzymes and produced low level β-mannan-degrading enzyme systems. The bacterium strain was found to be capable of producing pectinolytic enzymes on wheat bran at high level. Some of the strains have good potential for use as sources of important industrial enzymes.

  8. The effect of flavin electron shuttles in microbial fuel cells current production

    Energy Technology Data Exchange (ETDEWEB)

    Velasquez-Orta, Sharon B. [Newcastle Univ., Newcastle upon Tyne (United Kingdom). School of Civil Engineering and Geosciences; Newcastle Univ., Newcastle upon Tyne (United Kingdom). School of Chemical Engineering and Advanced Materials; Head, Ian M.; Curtis, Thomas P. [Newcastle Univ., Newcastle upon Tyne (United Kingdom). School of Civil Engineering and Geosciences; Scott, Keith [Newcastle Univ., Newcastle upon Tyne (United Kingdom). School of Chemical Engineering and Advanced Materials; Lloyd, Jonathan R.; Canstein, Harald von [Manchester Univ. (United Kingdom). School of Earth, Atmospheric and Environmental Sciences

    2010-02-15

    The effect of electron shuttles on electron transfer to microbial fuel cell (MFC) anodes was studied in systems where direct contact with the anode was precluded. MFCs were inoculated with Shewanella cells, and flavins used as the electron shuttling compound. In MFCs with no added electron shuttles, flavin concentrations monitored in the MFCs' bulk liquid increased continuously with FMN as the predominant flavin. The maximum concentrations were 0.6 {mu}M for flavin mononucleotide and 0.2 {mu}M for riboflavin. In MFCs with added flavins, micro-molar concentrations were shown to increase current and power output. The peak current was at least four times higher in MFCs with high concentrations of flavins (4.5-5.5 {mu}M) than in MFCs with low concentrations (0.2-0.6 {mu}M). Although high power outputs (around 150 mW/m{sup 2}) were achieved in MFCs with high concentrations of flavins, a Clostridium-like bacterium along with other reactor limitations affected overall coulombic efficiencies (CE) obtained, achieving a maximum CE of 13%. Electron shuttle compounds (flavins) permitted bacteria to utilise a remote electron acceptor (anode) that was not accessible to the cells allowing current production until the electron donor (lactate) was consumed. (orig.)

  9. Removal of anaerobic soluble microbial products in a biological activated carbon reactor.

    Science.gov (United States)

    Dong, Xiaojing; Zhou, Weili; He, Shengbing

    2013-09-01

    The soluble microbial products (SMP) in the biological treatment effluent are generally of great amount and are poorly biodegradable. Focusing on the biodegradation of anaerobic SMP, the biological activated carbon (BAC) was introduced into the anaerobic system. The experiments were conducted in two identical lab-scale up-flow anaerobic sludge blanket (UASB) reactors. The high strength organics were degraded in the first UASB reactor (UASB1) and the second UASB (UASB2, i.e., BAC) functioned as a polishing step to remove SMP produced in UASB1. The results showed that 90% of the SMP could be removed before granular activated carbon was saturated. After the saturation, the SMP removal decreased to 60% on the average. Analysis of granular activated carbon adsorption revealed that the main role of SMP removal in BAC reactor was biodegradation. A strain of SMP-degrading bacteria, which was found highly similar to Klebsiella sp., was isolated, enriched and inoculated back to the BAC reactor. When the influent chemical oxygen demand (COD) was 10,000 mg/L and the organic loading rate achieved 10 kg COD/(m3 x day), the effluent from the BAC reactor could meet the discharge standard without further treatment. Anaerobic BAC reactor inoculated with the isolated Klebsiella was proved to be an effective, cheap and easy technical treatment approach for the removal of SMP in the treatment of easily-degradable wastewater with COD lower than 10,000 mg/L.

  10. Characterization of microbial communities and fungal metabolites on field grown strawberries from organic and conventional production

    DEFF Research Database (Denmark)

    Jensen, Birgit; Knudsen, Inge-Marie Birkedal; Andersen, Birgitte

    2013-01-01

    The background levels of culturable indigenous microbial communities (microbiotas) on strawberries were examined in a field survey with four conventional and four organic growers with different production practise and geographic distribution. The microbiota on apparently healthy strawberries...... produced cyclopenol, cyclopenin, and viridicatin on the artificially infected berries, while Altemaria arborescens produced tenuazonic acid, Alternaria tenuissima produced altertoxin land altenuene, and Trichoderma spp. produced several peptaibols. In conclusion, native strawberry microbiotas are highly...

  11. Flavin as an Indicator of the Rate-Limiting Factor for Microbial Current Production in Shewanella oneidensis MR-1

    International Nuclear Information System (INIS)

    Saito, Junki; Hashimoto, Kazuhito; Okamoto, Akihiro

    2016-01-01

    Microbial electrode catalysis such as microbial fuel cells or electrosynthesis involves electron exchange with the electrodes located at the cell exterior; i.e., extracellular electron transport (EET). Despite the vast amount of research on the kinetics of EET to optimize the catalysis rate, the relevance of other factors, including upstream metabolic reactions, has scarcely been investigated. Herein, we report an in vivo electrochemical assay to confirm whether EET limits anodic current production (j) for the lactate oxidation of Shewanella oneidensis MR-1. Addition of riboflavin, which specifically enhances the EET rate, increased j only in the early phase before j saturation. In contrast, when we removed a trace metal ion necessary for upstream reactions from the electrolyte, a significant decrease in j and the lactate consumption rate was observed only after j saturation. These data suggest that the limiting factor for j shifted from EET to upstream reactions, highlighting the general importance of enhancing, for example, microbial metabolism, especially for long-standing practical applications. Our concept to specifically control the rate of EET could be applicable to other bioelectrode catalysis systems as a strategy to monitor their rate-limiting factors.

  12. Kinetic modeling of cell metabolism for microbial production.

    Science.gov (United States)

    Costa, Rafael S; Hartmann, Andras; Vinga, Susana

    2016-02-10

    Kinetic models of cellular metabolism are important tools for the rational design of metabolic engineering strategies and to explain properties of complex biological systems. The recent developments in high-throughput experimental data are leading to new computational approaches for building kinetic models of metabolism. Herein, we briefly survey the available databases, standards and software tools that can be applied for kinetic models of metabolism. In addition, we give an overview about recently developed ordinary differential equations (ODE)-based kinetic models of metabolism and some of the main applications of such models are illustrated in guiding metabolic engineering design. Finally, we review the kinetic modeling approaches of large-scale networks that are emerging, discussing their main advantages, challenges and limitations. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Microbial community dynamics and biogas production from manure fractions in sludge bed anaerobic digestion.

    Science.gov (United States)

    Nordgård, A S R; Bergland, W H; Bakke, R; Vadstein, O; Østgaard, K; Bakke, I

    2015-12-01

    To elucidate how granular sludge inoculum and particle-rich organic loading affect the structure of the microbial communities and process performance in upflow anaerobic sludge bed (UASB) reactors. We investigated four reactors run on dairy manure filtrate and four on pig manure supernatant for three months achieving similar methane yields. The reactors fed with less particle rich pig manure stabilized faster and had highest capacity. Microbial community dynamics analysed by a PCR/denaturing gradient gel electrophoresis approach showed that influent was a major determinant for the composition of the reactor communities. Comparisons of pre- and non-adapted inoculum in the reactors run on pig manure supernatant showed that the community structure of the nonadapted inoculum adapted in approximately two months. Microbiota variance partitioning analysis revealed that running time, organic loading rate and inoculum together explained 26 and 31% of the variance in bacterial and archaeal communities respectively. The microbial communities of UASBs adapted to the reactor conditions in treatment of particle rich manure fractions, obtaining high capacity, especially on pig manure supernatant. These findings provide relevant insight into the microbial community dynamics in startup and operation of sludge bed reactors for methane production from slurry fractions, a major potential source of biogas. © 2015 The Society for Applied Microbiology.

  14. Acetaldehyde production and microbial colonization in oral squamous cell carcinoma and oral lichenoid disease.

    Science.gov (United States)

    Marttila, Emilia; Uittamo, Johanna; Rusanen, Peter; Lindqvist, Christian; Salaspuro, Mikko; Rautemaa, Riina

    2013-07-01

    The main aim of this prospective study was to explore the ability of the oral microbiome to produce acetaldehyde in ethanol incubation. A total of 90 patients [30 oral squamous cell carcinoma (OSCC); 30 oral lichenoid disease (OLD); 30 healthy controls (CO)] were enrolled in the study. Microbial samples were taken from the mucosa using a filter paper method. The density of microbial colonization was calculated and the spectrum analyzed. Microbial acetaldehyde production was measured by gas chromatography. The majority (68%) of cultures produced carcinogenic levels of acetaldehyde (>100 μM) when incubated with ethanol (22 mM). The mean acetaldehyde production by microbes cultured from smoker samples was significantly higher (213 μM) than from non-smoker samples (141 μM) (P=.0326). The oral microbiota from OSCC, OLD patients and healthy individuals are able to produce carcinogenic levels of acetaldehyde. The present provisional study suggests smoking may increase the production of acetaldehyde. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Microbial methane production in oxygenated water column of an oligotrophic lake

    Science.gov (United States)

    Grossart, Hans-Peter; Frindte, Katharina; Dziallas, Claudia; Eckert, Werner; Tang, Kam W.

    2011-01-01

    The prevailing paradigm in aquatic science is that microbial methanogenesis happens primarily in anoxic environments. Here, we used multiple complementary approaches to show that microbial methane production could and did occur in the well-oxygenated water column of an oligotrophic lake (Lake Stechlin, Germany). Oversaturation of methane was repeatedly recorded in the well-oxygenated upper 10 m of the water column, and the methane maxima coincided with oxygen oversaturation at 6 m. Laboratory incubations of unamended epilimnetic lake water and inoculations of photoautotrophs with a lake-enrichment culture both led to methane production even in the presence of oxygen, and the production was not affected by the addition of inorganic phosphate or methylated compounds. Methane production was also detected by in-lake incubations of lake water, and the highest production rate was 1.8–2.4 nM⋅h−1 at 6 m, which could explain 33–44% of the observed ambient methane accumulation in the same month. Temporal and spatial uncoupling between methanogenesis and methanotrophy was supported by field and laboratory measurements, which also helped explain the oversaturation of methane in the upper water column. Potentially methanogenic Archaea were detected in situ in the oxygenated, methane-rich epilimnion, and their attachment to photoautotrophs might allow for anaerobic growth and direct transfer of substrates for methane production. Specific PCR on mRNA of the methyl coenzyme M reductase A gene revealed active methanogenesis. Microbial methane production in oxygenated water represents a hitherto overlooked source of methane and can be important for carbon cycling in the aquatic environments and water to air methane flux. PMID:22089233

  16. Microbial community production, respiration, and structure of the microbial food web of an ecosystem in the northeastern Atlantic Ocean

    Science.gov (United States)

    Maixandeau, Anne; LefèVre, Dominique; Karayanni, Hera; Christaki, Urania; van Wambeke, France; Thyssen, Melilotus; Denis, Michel; FernáNdez, Camila I.; Uitz, Julia; Leblanc, Karine; QuéGuiner, Bernard

    2005-07-01

    Gross community production (GCP), dark community respiration (DCR), and the biomass of the different size classes of organisms in the microbial community were measured in the northeastern Atlantic basin as part of the Programme Océan Multidisciplinaire Méso Echelle (POMME) project. The field experiment was conducted during three seasons (winter, spring, and late summer-fall) in 2001. Samples were collected from four different mesoscale structures within the upper 100 m. GCP rates increased from winter (101 ± 24 mmol O2 m-2 d-1) to spring (153 ± 27 mmol O2 m-2 d-1) and then decreased from spring to late summer (44 ± 18 mmol O2 m-2 d-1). DCR rates increased from winter (-47 ± 18 mmol O2 m-2 d-1) to spring (-97 ± 7 mmol O2 m-2 d-1) and then decreased from spring to late summer (50 ± 7 mmol O2 m-2 d-1). The onset of stratification depended on latitude as well as on the presence of mesoscale structures (eddies), and this largely contributed to the variability of GCP. The trophic status of the POMME area was defined as net autotrophic, with a mean annual net community production rate of +38 ± 18 mmol O2 m-2 d-1, exhibiting a seasonal variation from +2 ± 20 mmol O2 m-2 d-1 to +57 ± 20 mmol O2 m-2 d-1. This study highlights that small organisms (picoautotrophs, nanoautotrophs, and bacteria) are the main organisms contributing to biological fluxes throughout the year and that episodic blooms of microphytoplankton are related to mesoscale structures.

  17. Substrate potential of last interglacial to Holocene permafrost organic matter for future microbial greenhouse gas production

    Science.gov (United States)

    Stapel, Janina G.; Schwamborn, Georg; Schirrmeister, Lutz; Horsfield, Brian; Mangelsdorf, Kai

    2018-04-01

    In this study the organic matter (OM) in several permafrost cores from Bol'shoy Lyakhovsky Island in NE Siberia was investigated. In the context of the observed global warming the aim was to evaluate the potential of freeze-locked OM from different depositional ages to act as a substrate provider for microbial production of greenhouse gases from thawing permafrost. To assess this potential, the concentrations of free and bound acetate, which form an appropriate substrate for methanogenesis, were determined. The largest free-acetate (in pore water) and bound-acetate (organic-matrix-linked) substrate pools were present in interstadial marine isotope stage (MIS) 3 and stadial MIS 4 Yedoma permafrost deposits. In contrast, deposits from the last interglacial MIS 5e (Eemian) contained only a small pool of substrates. The Holocene (MIS 1) deposits revealed a significant bound-acetate pool, representing a future substrate potential upon release during OM degradation. Additionally, pyrolysis experiments on the OM allocated an increased aliphatic character to the MIS 3 and 4 Late Pleistocene deposits, which might indicate less decomposed and presumably more easily degradable OM. Biomarkers for past microbial communities, including those for methanogenic archaea, also showed the highest abundance during MIS 3 and 4, which indicated OM-stimulated microbial degradation and presumably greenhouse gas production during time of deposition. On a broader perspective, Arctic warming will increase and deepen permafrost thaw and favor substrate availability from older freeze-locked permafrost deposits. Thus, the Yedoma deposits especially showed a high potential for providing substrates relevant for microbial greenhouse gas production.

  18. Microbial production of polyhydroxybutyrate with tailor-made properties: an integrated modelling approach and experimental validation.

    Science.gov (United States)

    Penloglou, Giannis; Chatzidoukas, Christos; Kiparissides, Costas

    2012-01-01

    The microbial production of polyhydroxybutyrate (PHB) is a complex process in which the final quantity and quality of the PHB depend on a large number of process operating variables. Consequently, the design and optimal dynamic operation of a microbial process for the efficient production of PHB with tailor-made molecular properties is an extremely interesting problem. The present study investigates how key process operating variables (i.e., nutritional and aeration conditions) affect the biomass production rate and the PHB accumulation in the cells and its associated molecular weight distribution. A combined metabolic/polymerization/macroscopic modelling approach, relating the process performance and product quality with the process variables, was developed and validated using an extensive series of experiments and measurements. The model predicts the dynamic evolution of the biomass growth, the polymer accumulation, the consumption of carbon and nitrogen sources and the average molecular weights of the PHB in a bioreactor, under batch and fed-batch operating conditions. The proposed integrated model was used for the model-based optimization of the production of PHB with tailor-made molecular properties in Azohydromonas lata bacteria. The process optimization led to a high intracellular PHB accumulation (up to 95% g of PHB per g of DCW) and the production of different grades (i.e., different molecular weight distributions) of PHB. Copyright © 2011 Elsevier Inc. All rights reserved.

  19. First evaluation of alkylpyrazine application as a novel method to decrease microbial contaminations in processed meat products.

    Science.gov (United States)

    Schöck, Matthias; Liebminger, Stefan; Berg, Gabriele; Cernava, Tomislav

    2018-04-03

    Every year about 20% of the globally produced meat gets lost due to microbial spoilage. Nevertheless, the demand for processed meat is constantly rising and producers are searching for novel strategies to reduce microbial contaminations in their products. In the present study, we evaluated the applicability of alkylpyrazines as antimicrobial agents. These fragrant molecules naturally occur in different vegetables, fruits, roasted nut and meat. Several pyrazine derivatives are readily added to processed products for flavoring purposes in the food industry. To evaluate their potential for application, two derivatives were tested for their antimicrobial activity against meat-associated bacterial contaminants and chicken meat as a whole. Isolates assigned to Carnobacteriaceae, Enterobacteriaceae, Listeriaceae, and Moraxellaceae were substantially inhibited in the pilot tests. Moreover, treatments of pyrazine-susceptible isolates resulted in 4-log reductions in bacterial cell counts. The effect was more pronounced when the model contaminants were exposed to higher concentrations of 5-isobutyl-2,3-dimethylpyrazine. In a first small-scale application with processed chicken meat, it was demonstrated that the antimicrobial effects of 2-isobutyl-3-methylpyrazine can be improved by additionally lowering the water activity on the meat surface when maltodextrin is used as a carrier substance. At low pyrazine dosages, the number of viable bacteria was decreased up to 95% in comparison to the corresponding controls. A complementary imaging method that was developed to assess the efficacy on the product, reinforced the applicability of this two-component system.

  20. Two Strategies for Microbial Production of an Industrial Enzyme-Alpha-Amylase

    Science.gov (United States)

    Bernhardsdotter, Eva C. M. J.; Garriott, Owen; Pusey, Marc L.; Ng, Joseph D.

    2003-01-01

    Extremophiles are microorganisms that thrive in, from an anthropocentric view, extreme environments including hot springs, soda lakes and arctic water. This ability of survival at extreme conditions has rendered extremophiles to be of interest in astrobiology, evolutionary biology as well as in industrial applications. Of particular interest to the biotechnology industry are the biological catalysts of the extremophiles, the extremozymes, whose unique stabilities at extreme conditions make them potential sources of novel enzymes in industrial applications. There are two major approaches to microbial enzyme production. This entails enzyme isolation directly from the natural host or creating a recombinant expression system whereby the targeted enzyme can be overexpressed in a mesophilic host. We are employing both methods in the effort to produce alpha-amylases from a hyperthermophilic archaeon (Thermococcus) isolated from a hydrothermal vent in the Atlantic Ocean, as well as from alkaliphilic bacteria (Bacillus) isolated from a soda lake in Tanzania. Alpha-amylases catalyze the hydrolysis of internal alpha-1,4-glycosidic linkages in starch to produce smaller sugars. Thermostable alpha-amylases are used in the liquefaction of starch for production of fructose and glucose syrups, whereas alpha-amylases stable at high pH have potential as detergent additives. The alpha-amylase encoding gene from Thermococcus was PCR amplified using carefully designed primers and analyzed using bioinformatics tools such as BLAST and Multiple Sequence Alignment for cloning and expression in E.coli. Four strains of Bacillus were grown in alkaline starch-enriched medium of which the culture supernatant was used as enzyme source. Amylolytic activity was detected using the starch-iodine method.

  1. Innovative self-powered submersible microbial electrolysis cell (SMEC) for biohydrogen production from anaerobic reactors

    DEFF Research Database (Denmark)

    Zhang, Yifeng; Angelidaki, Irini

    2012-01-01

    A self-powered submersible microbial electrolysis cell (SMEC), in which a specially designed anode chamber and external electricity supply were not needed, was developed for in situ biohydrogen production from anaerobic reactors. In batch experiments, the hydrogen production rate reached 17.8 m...... improvement of voltage output and reduction of electron losses were essential for efficient hydrogen generation. In addition, alternate exchanging the electricity-assisting and hydrogen-producing function between the two cell units of the SMEC was found to be an effective approach to inhibit methanogens...

  2. Implications of Extracellular Polymeric Substance Matrices of Microbial Habitats Associated with Coastal Aquaculture Systems

    Directory of Open Access Journals (Sweden)

    Juan Carlos Camacho-Chab

    2016-08-01

    Full Text Available Coastal zones support fisheries that provide food for humans and feed for animals. The decline of fisheries worldwide has fostered the development of aquaculture. Recent research has shown that extracellular polymeric substances (EPS synthesized by microorganisms contribute to sustainable aquaculture production, providing feed to the cultured species, removing waste and contributing to the hygiene of closed systems. As ubiquitous components of coastal microbial habitats at the air–seawater and seawater–sediment interfaces as well as of biofilms and microbial aggregates, EPS mediate deleterious processes that affect the performance and productivity of aquaculture facilities, including biofouling of marine cages, bioaccumulation and transport of pollutants. These biomolecules may also contribute to the persistence of harmful algal blooms (HABs and their impact on cultured species. EPS may also exert a positive influence on aquaculture activity by enhancing the settling of aquaculturally valuable larvae and treating wastes in bioflocculation processes. EPS display properties that may have biotechnological applications in the aquaculture industry as antiviral agents and immunostimulants and as a novel source of antifouling bioproducts.

  3. Modern microbial solid state fermentation technology for future biorefineries for the production of added-value products

    Directory of Open Access Journals (Sweden)

    Musaalbakri Abdul Manan

    2017-12-01

    Full Text Available The promise of industrial biotechnology has been around since Chaim Weizmann developed acetone–butanol–ethanol fermentation at the University of Manchester in 1917 and the prospects nowadays look brighter than ever. Today’s biorefinery technologies would be almost unthinkable without biotechnology. This is a growing trend and biorefineries have also increased in importance in agriculture and the food industry. Novel biorefinery processes using solid state fermentation (SSF technology have been developed as alternative to conventional processing routes, leading to the production of added-value products from agriculture and food industry raw materials. SSF involves the growth of microorganisms on moist solid substrate in the absence of free-flowing water. Future biorefineries based on SSF aim to exploit the vast complexity of the technology to modify biomass produced by agriculture and the food industry for valuable by-products through microbial bioconversion. In this review, a summary has been made of the attempts at using modern microbial SSF technology for future biorefineries for the production of many added-value products ranging from feedstock for the fermentation process and biodegradable plastics to fuels and chemicals.

  4. Microbial genome mining for accelerated natural products discovery: is a renaissance in the making?

    Science.gov (United States)

    Bachmann, Brian O; Van Lanen, Steven G; Baltz, Richard H

    2014-02-01

    Microbial genome mining is a rapidly developing approach to discover new and novel secondary metabolites for drug discovery. Many advances have been made in the past decade to facilitate genome mining, and these are reviewed in this Special Issue of the Journal of Industrial Microbiology and Biotechnology. In this Introductory Review, we discuss the concept of genome mining and why it is important for the revitalization of natural product discovery; what microbes show the most promise for focused genome mining; how microbial genomes can be mined; how genome mining can be leveraged with other technologies; how progress on genome mining can be accelerated; and who should fund future progress in this promising field. We direct interested readers to more focused reviews on the individual topics in this Special Issue for more detailed summaries on the current state-of-the-art.

  5. Microbial decontamination of cosmetic raw materials and personal care products by irradiation

    International Nuclear Information System (INIS)

    Katusin-Razem, B.; Mihaljevic, B.; Razem, D.

    2005-01-01

    Typical levels of sporadically occurring (dynamic) microbial contamination of cosmetic raw materials: pigments, abrasives and liposomes, as well as of final products for personal care, i.e. toothpaste, crayons, shampoos, cleansers and creams, were evaluated. In most cases, contamination was dominated by a single population of microorganisms, either Gram-negative bacteria or molds. The feasibility of microbial decontamination by irradiation was studied by determining the resistance to gamma radiation of contaminating microflora in situ. It was expressed as a dose required for the first 90% reduction, D first 9 0% red. The values in the range 1-2 kGy for molds and 0.1-0.6 kGy for Gram-negative bacteria were obtained. This relatively high susceptibility to irradiation allowed inactivation factors close to 6 to be achieved with doses generally not exceeding 3 kGy, and yielding endpoint contamination less than 10 g -1 . (author)

  6. Microbial decontamination of cosmetic raw materials and personal care products by irradiation

    International Nuclear Information System (INIS)

    Katusin-Razem, Branka; Mihaljevic, Branka; Razem, D.

    2003-01-01

    Typical levels of sporadically occurring (dynamic) microbial contamination of cosmetic raw materials: pigments, abrasives and liposomes, as well as of final products for personal care: toothpaste, crayons, shampoos, cleansers and creams, were evaluated. In most cases the contamination was dominated by a single population of microorganisms, either Gram-negative bacteria or molds. The feasibility of microbial decontamination by irradiation was studied by determining the resistance to gamma radiation of contaminating microflora in situ. It was expressed as a dose required for the first 90% reduction, D first 9 0% r ed . The values in the range 1-2 kGy for molds and 0.1-0.6 kGy for Gram-negative bacteria were obtained. This relatively high susceptibility to irradiation allowed inactivation factors close to 6 to be achieved with doses generally not exceeding 3 kGy, and yielding endpoint contamination less than 10/g

  7. Microbial production host selection for converting second-generation feedstocks into bioproducts

    Directory of Open Access Journals (Sweden)

    van Groenestijn Johan W

    2009-12-01

    Full Text Available Abstract Background Increasingly lignocellulosic biomass hydrolysates are used as the feedstock for industrial fermentations. These biomass hydrolysates are complex mixtures of different fermentable sugars, but also inhibitors and salts that affect the performance of the microbial production host. The performance of six industrially relevant microorganisms, i.e. two bacteria (Escherichia coli and Corynebacterium glutamicum, two yeasts (Saccharomyces cerevisiae and Pichia stipitis and two fungi (Aspergillus niger and Trichoderma reesei were compared for their (i ability to utilize monosaccharides present in lignocellulosic hydrolysates, (ii resistance against inhibitors present in lignocellulosic hydrolysates, (iii their ability to utilize and grow on different feedstock hydrolysates (corn stover, wheat straw, sugar cane bagasse and willow wood. The feedstock hydrolysates were generated in two manners: (i thermal pretreatment under mild acid conditions followed by enzymatic hydrolysis and (ii a non-enzymatic method in which the lignocellulosic biomass is pretreated and hydrolyzed by concentrated sulfuric acid. Moreover, the ability of the selected hosts to utilize waste glycerol from the biodiesel industry was evaluated. Results Large differences in the performance of the six tested microbial production hosts were observed. Carbon source versatility and inhibitor resistance were the major discriminators between the performances of these microorganisms. Surprisingly all 6 organisms performed relatively well on pretreated crude feedstocks. P. stipitis and A. niger were found to give the overall best performance C. glutamicum and S. cerevisiae were shown to be the least adapted to renewable feedstocks. Conclusion Based on the results obtained we conclude that a substrate oriented instead of the more commonly used product oriented approach towards the selection of a microbial production host will avoid the requirement for extensive metabolic

  8. Biodiesel biorefinery: opportunities and challenges for microbial production of fuels and chemicals from glycerol waste

    Directory of Open Access Journals (Sweden)

    Almeida João R M

    2012-07-01

    Full Text Available Abstract The considerable increase in biodiesel production worldwide in the last 5 years resulted in a stoichiometric increased coproduction of crude glycerol. As an excess of crude glycerol has been produced, its value on market was reduced and it is becoming a “waste-stream” instead of a valuable “coproduct”. The development of biorefineries, i.e. production of chemicals and power integrated with conversion processes of biomass into biofuels, has been singled out as a way to achieve economically viable production chains, valorize residues and coproducts, and reduce industrial waste disposal. In this sense, several alternatives aimed at the use of crude glycerol to produce fuels and chemicals by microbial fermentation have been evaluated. This review summarizes different strategies employed to produce biofuels and chemicals (1,3-propanediol, 2,3-butanediol, ethanol, n-butanol, organic acids, polyols and others by microbial fermentation of glycerol. Initially, the industrial use of each chemical is briefly presented; then we systematically summarize and discuss the different strategies to produce each chemical, including selection and genetic engineering of producers, and optimization of process conditions to improve yield and productivity. Finally, the impact of the developments obtained until now are placed in perspective and opportunities and challenges for using crude glycerol to the development of biodiesel-based biorefineries are considered. In conclusion, the microbial fermentation of glycerol represents a remarkable alternative to add value to the biodiesel production chain helping the development of biorefineries, which will allow this biofuel to be more competitive.

  9. Modeling Novo Nordisk Production Systems

    DEFF Research Database (Denmark)

    Miller, Thomas Dedenroth

    1997-01-01

    This report describes attributes of models and systems, and how models can be used for description of production systems. There are special attention on the 'Theory of Domains'.......This report describes attributes of models and systems, and how models can be used for description of production systems. There are special attention on the 'Theory of Domains'....

  10. Microbial-immune cross-talk and regulation of the immune system.

    Science.gov (United States)

    Cahenzli, Julia; Balmer, Maria L; McCoy, Kathy D

    2013-01-01

    We are all born germ-free. Following birth we enter into a lifelong relationship with microbes residing on our body's surfaces. The lower intestine is home to the highest microbial density in our body, which is also the highest microbial density known on Earth (up to 10(12) /g of luminal contents). With our indigenous microbial cells outnumbering our human cells by an order of magnitude our body is more microbial than human. Numerous immune adaptations confine these microbes within the mucosa, enabling most of us to live in peaceful homeostasis with our intestinal symbionts. Intestinal epithelial cells not only form a physical barrier between the bacteria-laden lumen and the rest of the body but also function as multi-tasking immune cells that sense the prevailing microbial (apical) and immune (basolateral) milieus, instruct the underlying immune cells, and adapt functionally. In the constant effort to ensure intestinal homeostasis, the immune system becomes educated to respond appropriately and in turn immune status can shape the microbial consortia. Here we review how the dynamic immune-microbial dialogue underlies maturation and regulation of the immune system and discuss recent findings on the impact of diet on both microbial ecology and immune function. © 2012 The Authors. Immunology © 2012 Blackwell Publishing Ltd.

  11. Radiochemically-Supported Microbial Communities: A Potential Mechanism for Biocolloid Production of Importance to Actinide Transport

    Energy Technology Data Exchange (ETDEWEB)

    Moser, Duane P. [Desert Research Inst., Nevada University, Reno, NV (United States); Hamilton-Brehm, Scott D. [Desert Research Inst., Nevada University, Reno, NV (United States); Fisher, Jenny C. [Desert Research Inst., Nevada University, Reno, NV (United States); Bruckner, James C. [Desert Research Inst., Nevada University, Reno, NV (United States); Kruger, Brittany [Desert Research Inst., Nevada University, Reno, NV (United States); Sackett, Joshua [Desert Research Inst., Nevada University, Reno, NV (United States); Russell, Charles E. [Desert Research Inst., Nevada University, Reno, NV (United States); Onstott, Tullis C. [Princeton Univ., NJ (United States); Czerwinski, Ken [Univ. of Nevada, Las Vegas, NV (United States); Zavarin, Mavrik [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Campbell, James H. [Northwest Missouri State Univ., Maryville, MO (United States)

    2014-06-01

    Due to the legacy of Cold War nuclear weapons testing, the Nevada National Security Site (NNSS, formerly known as the Nevada Test Site (NTS)) contains millions of Curies of radioactive contamination. Presented here is a summary of the results of the first comprehensive study of subsurface microbial communities of radioactive and nonradioactive aquifers at this site. To achieve the objectives of this project, cooperative actions between the Desert Research Institute (DRI), the Nevada Field Office of the National Nuclear Security Administration (NNSA), the Underground Test Area Activity (UGTA), and contractors such as Navarro-Interra (NI), were required. Ultimately, fluids from 17 boreholes and two water-filled tunnels were sampled (sometimes on multiple occasions and from multiple depths) from the NNSS, the adjacent Nevada Test and Training Range (NTTR), and a reference hole in the Amargosa Valley near Death Valley. The sites sampled ranged from highly-radioactive nuclear device test cavities to uncontaminated perched and regional aquifers. Specific areas sampled included recharge, intermediate, and discharge zones of a 100,000-km2 internally-draining province, known as the Death Valley Regional Flow System (DVRFS), which encompasses the entirety of the NNSS/NTTR and surrounding areas. Specific geological features sampled included: West Pahute and Ranier Mesas (recharge zone), Yucca and Frenchman Flats (transitional zone), and the Western edge of the Amargosa Valley near Death Valley (discharge zone). The original overarching question underlying the proposal supporting this work was stated as: Can radiochemically-produced substrates support indigenous microbial communities and subsequently stimulate biocolloid formation that can affect radionuclides in NNSS subsurface nuclear test/detonation sites? Radioactive and non-radioactive groundwater samples were thus characterized for physical parameters, aqueous geochemistry, and microbial communities using both DNA- and

  12. Production Systems and Supplier Selection

    DEFF Research Database (Denmark)

    Pedraza-Acosta, Isabel; Pilkington, Alan; Barnes, David

    2016-01-01

    strategic stamping suppliers. Findings: Our contribution is the multi-phased production and product innovation process. This is an advance from traditional supplier selection and also an extension of ideas of supplier-located product development as it includes production system development, and complements...

  13. Soil microbial properties after long-term swine slurry application to conventional and no-tillage systems in Brazil.

    Science.gov (United States)

    Balota, Elcio L; Machineski, Oswaldo; Hamid, Karima I A; Yada, Ines F U; Barbosa, Graziela M C; Nakatani, Andre S; Coyne, Mark S

    2014-08-15

    Swine waste can be used as an agricultural fertilizer, but large amounts may accumulate excess nutrients in soil or contaminate the surrounding environment. This study evaluated long-term soil amendment (15 years) with different levels of swine slurry to conventional (plow) tillage (CT) and no tillage (NT) soils. Long-term swine slurry application did not affect soil organic carbon. Some chemical properties, such as calcium, base saturation, and aluminum saturation were significantly different within and between tillages for various application rates. Available P and microbial parameters were significantly affected by slurry addition. Depending on tillage, soil microbial biomass and enzyme activity increased up to 120 m(3) ha(-1) year(-1) in all application rates. The NT system had higher microbial biomass and activity than CT at all application levels. There was an inverse relationship between the metabolic quotient (qCO2) and MBC, and the qCO2 was 53% lower in NT than CT. Swine slurry increased overall acid phosphatase activity, but the phosphatase produced per unit of microbial biomass decreased. A comparison of data obtained in the 3rd and 15th years of swine slurry application indicated that despite slurry application the CT system degraded with time while the NT system had improved values of soil quality indicators. For these Brazilian oxisols, swine slurry amendment was insufficient to maintain soil quality parameters in annual crop production without additional changes in tillage management. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Microbial plant litter decomposition in aquatic and terrestrial boreal systems along a natural fertility gradient

    Science.gov (United States)

    Soares, A. Margarida P. M.; Kritzberg, Emma S.; Rousk, Johannes

    2017-04-01

    Plant litter decomposition is a global ecosystem process, with a crucial role in carbon and nutrient cycling. The majority of litter processing occurs in terrestrial systems, but an important fraction also takes place in inland waters. Among environmental factors, pH impacts the litter decomposition through its selective influence on microbial decomposers. Fungal communities are less affected by pH than bacteria, possibly owing to a wider pH tolerance by this group. On the other hand, bacterial pH optima are constrained to a narrower range of pH values. The microbial decomposition of litter is universally nutrient limited; but few comparisons exist between terrestrial and aquatic systems. We investigated the microbial colonisation and decomposition of plant litter along a fertility gradient, which varied in both pH and N availability in both soil and adjacent water. To do this we installed litterbags with birch (Betula pendula) in streams and corresponding soils in adjacent riparian areas in a boreal system, in Krycklan, Sweden. During the four months covering the ice-free growth season we monitored the successional dynamics of fungal (acetate incorporation into ergosterol) and bacterial growth (thymidine incorporation), microbial respiration in leaf litter, and quantitative and qualitative changes in litter over time. We observed that bacterial growth rates were initially higher in litter decomposing in streams than those in soils, but differences between terrestrial and aquatic bacterial production converged towards the end of the experiment. In litter bags installed in soils, bacterial growth was lower at sites with more acidic pH and lower N availability, while aquatic bacteria were relatively unaffected by the fertility level. Fungal growth rates were two-fold higher for litter decomposing in streams than in soils. In aquatic systems, fungal growth was initially lower in low fertility sites, but differences gradually disappeared over the time course. Fungal

  15. PCE dechlorination by non-Dehalococcoides in a microbial electrochemical system.

    Science.gov (United States)

    Yu, Jaecheul; Park, Younghyun; Nguyen, Van Khanh; Lee, Taeho

    2016-08-01

    The bioremediation of tetrachloroethene (perchloroethene; PCE) contaminated sites generally requires a supply of some fermentable organic substrates as an electron donor. On the other hand, organic substrates can induce the massive growth of microorganisms around the injection wells, which can foul the contaminated subsurface environment. In this study, PCE dechlorination to ethene was performed in a microbial electrochemical system (MES) using the electrode (a cathode polarized at -500 mV vs. standard hydrogen electrode) as the electron donor. Denaturing gel gradient electrophoresis and pyrosequencing revealed a variety of non-Dehalococcoides bacteria dominant in MES, such as Acinetobacter sp. (25.7 % for AS1 in suspension of M3), Rhodopseudomonas sp. (10.5 % for AE1 and 10.1 % for AE2 in anodic biofilm of M3), Pseudomonas aeruginosa (22.4 % for BS1 in suspension of M4), and Enterobacter sp. (21.7 % for BE1 in anodic biofilm of M4) which are capable of electron transfer, hydrogen production and dechlorination. The Dehalococcoides group, however, was not detected in this system. Therefore, these results suggest that a range of bacterial species outside the Dehalococcoides can play an important role in the microbial electrochemical dechlorination process, which may lead to innovative bioremediation technology.

  16. Soluble Microbial Product Characterization of Biofilm Formation in Bench-Scale

    KAUST Repository

    Mines, Paul

    2012-12-01

    The biological process known as activated sludge (AS) in conjunction with membrane separation technology for the treatment of wastewater has been employed for over four decades. While, membrane biological reactors (MBR) are now widely employed, the phenomenon of membrane fouling is still the most significant factor leading to performance decline of MBRs. Although much research has been done on the subject of MBR fouling over the past two decades, many questions remain unanswered, and consensus within the scientific community is rare. However, research has led to one system parameter generally being regarded as a contributor to membrane fouling, extracellular polymeric compounds (EPS). EPS, and more specifically, the soluble fraction of EPS known as soluble microbial products (SMP), must be further investigated in order to better understand membrane fouling. The biological activity and performance of the MBR is affected by myriad operational parameters, which in turn affects the SMP generated. A commonly varied operational parameter is, depending on the specific treatment needs of a MBR, the sludge retention time (SRT). This study aims to characterize the SMP in three bench-scale MBRs as the SRT is gradually lowered. By studying how the SMP change as the operation of the system is altered, greater understanding of how SMP are related to fouling can be achieved. At the onset of the study, a steady state was established in the system with a SRT of 20 days. Upon stabilization of a 20 day SRT, the system was gradually transitioned to a five and a half day SRT, in stepwise adjustments. Initially, both the trans-membrane pressure (TMP) and the SMP concentrations were at relatively low values, indicating the presence of minimal amounts of biofilm on the membrane surfaces. As the system was altered and more activated sludge was wasted from the reactors, the SRT inherently decreased. As the lower SRT was transitioned and established, the data from TMP measurements, as well

  17. Engineering soil organic matter quality: Biodiesel Co-Product (BCP) stimulates exudation of nitrogenous microbial biopolymers

    Science.gov (United States)

    Redmile-Gordon, Marc A.; Evershed, Richard P.; Kuhl, Alison; Armenise, Elena; White, Rodger P.; Hirsch, Penny R.; Goulding, Keith W.T.; Brookes, Philip C.

    2015-01-01

    Biodiesel Co-Product (BCP) is a complex organic material formed during the transesterification of lipids. We investigated the effect of BCP on the extracellular microbial matrix or ‘extracellular polymeric substance’ (EPS) in soil which is suspected to be a highly influential fraction of soil organic matter (SOM). It was hypothesised that more N would be transferred to EPS in soil given BCP compared to soil given glycerol. An arable soil was amended with BCP produced from either 1) waste vegetable oils or 2) pure oilseed rape oil, and compared with soil amended with 99% pure glycerol; all were provided with 15N labelled KNO3. We compared transfer of microbially assimilated 15N into the extracellular amino acid pool, and measured concomitant production of exopolysaccharide. Following incubation, the 15N enrichment of total hydrolysable amino acids (THAAs) indicated that intracellular anabolic products had incorporated the labelled N primarily as glutamine and glutamate. A greater proportion of the amino acids in EPS were found to contain 15N than those in the THAA pool, indicating that the increase in EPS was comprised of bioproducts synthesised de novo. Moreover, BCP had increased the EPS production efficiency of the soil microbial community (μg EPS per unit ATP) up to approximately double that of glycerol, and caused transfer of 21% more 15N from soil solution into EPS-amino acids. Given the suspected value of EPS in agricultural soils, the use of BCP to stimulate exudation is an interesting tool to consider in the theme of delivering sustainable intensification. PMID:26635420

  18. Recent advances in microbial production of mannitol: utilization of low-cost substrates, strain development and regulation strategies.

    Science.gov (United States)

    Zhang, Min; Gu, Lei; Cheng, Chao; Ma, Jiangfeng; Xin, Fengxue; Liu, Junli; Wu, Hao; Jiang, Min

    2018-02-26

    Mannitol has been widely used in fine chemicals, pharmaceutical industries, as well as functional foods due to its excellent characteristics, such as antioxidant protecting, regulation of osmotic pressure and non-metabolizable feature. Mannitol can be naturally produced by microorganisms. Compared with chemical manufacturing, microbial production of mannitol provides high yield and convenience in products separation; however the fermentative process has not been widely adopted yet. A major obstacle to microbial production of mannitol under industrial-scale lies in the low economical efficiency, owing to the high cost of fermentation medium, leakage of fructose, low mannitol productivity. In this review, recent advances in improving the economical efficiency of microbial production of mannitol were reviewed, including utilization of low-cost substrates, strain development for high mannitol yield and process regulation strategies for high productivity.

  19. Microbial electrosynthesis for acetate production from carbon dioxide: innovative biocatalysts leading to enhanced performance

    DEFF Research Database (Denmark)

    Aryal, Nabin

    Production of chemicals has significant influence on the emission of greenhouse gases (GHG) in particular carbon dioxide (CO2), thereby contributing to the climate changes of our planet. There is a general acceptance that we need to reduce the emission of GHG on a global level to cope with these ......Production of chemicals has significant influence on the emission of greenhouse gases (GHG) in particular carbon dioxide (CO2), thereby contributing to the climate changes of our planet. There is a general acceptance that we need to reduce the emission of GHG on a global level to cope...... with these changes. Production of chemicals utilization of CO2 as feedstock represents a sustainable alternative to many fossil derived products, which are non-renewable and have a strong negative impact on the environment. Microbial electrosynthesis (MES) is an emerging technique utilizing electrical energy...

  20. Recent Advances in the Study of Marine Microbial Biofilm: From the Involvement of Quorum Sensing in Its Production up to Biotechnological Application of the Polysaccharide Fractions

    Directory of Open Access Journals (Sweden)

    Paola Di Donato

    2016-05-01

    Full Text Available The present review will explore the most relevant findings on marine microbial biofilm, with particular attention towards its polysaccharide fraction, namely exopolysaccharide (EPS. EPSs of microbial origin are ubiquitous in nature, possess unique properties and can be isolated from the bacteria living in a variety of habitats, including fresh water or marine environments, extreme environments or different soil ecosystems. These biopolymers have many application in the field of biotechnology. Several studies showed that the biofilm formation is closely related to quorum sensing (QS systems, which is a mechanism relying on the production of small molecules defined as “autoinducers” that bacteria release in the surrounding environment where they accumulate. In this review, the involvement of microbial chemical communication, by QS mechanism, in the formation of marine biofilm will also be discussed.

  1. Winter−spring transition in the subarctic Atlantic: microbial response to deep mixing and pre-bloom production

    DEFF Research Database (Denmark)

    Paulsen, Maria Lund; Riisgaard, Karen; Thingstad, T. Frede

    2015-01-01

    In temperate, subpolar and polar marine systems, the classical perception is that diatoms initiate the spring bloom and thereby mark the beginning of the productive season. Contrary to this view, we document an active microbial food web dominated by pico- and nanoplankton prior to the diatom bloom......, a period with excess nutrients and deep convection of the water column. During repeated visits to stations in the deep Iceland and Norwegian basins and the shallow Shetland Shelf (26 March to 29 April 2012), we investigated the succession and dynamics of photo - synthetic and heterotrophic microorganisms....... We observed that the early phytoplankton production was followed by a decrease in the carbon:nitrogen ratio of the dissolved organic matter in the deep mixed stations, an increase in heterotrophic prokaryote (bacteria) abundance and activity (indicated by the high nucleic acid:low nucleic acid...

  2. Microbial Geochemistry in Shallow-Sea Hydrothermal Systems

    Science.gov (United States)

    Amend, J. P.; Pichler, T.

    2006-12-01

    Shallow-sea hydrothermal systems are far more ubiquitous than generally recognized. Approximately 50-60 systems are currently known, occurring world-wide in areas of high heat flow, such as, volcanic island arcs, near-surface mid-ocean ridges, and intraplate oceanic volcanoes. In contrast to deep-sea systems, shallow- sea vent fluids generally include a meteoric component, they experience phase separation near the sediment- water interface, and they discharge into the photic zone (thermophilic bacteria and archaea. Perhaps because deep-sea smokers and continental hot springs are visually more stunning, shallow-sea systems are often overlooked study sites. We will discuss their particular features that afford unique opportunities in microbial geochemistry. Two of the better studied examples are at Vulcano Island (Italy) and Ambitle Island (Papua New Guinea). The vents and sediment seeps at Vulcano are the "type locality" for numerous cultured hyperthermophiles, including the bacteria Aquifex and Thermotoga, the crenarchaeon Pyrodictium, and the Euryarchaeota Archaeoglobus and Pyrococcus. Isotope-labeled incubation experiments of heated sediments and an array of culturing studies have shown that simple organic compounds are predominantly fermented or anaerobically respired with sulfate. 16S rRNA gene surveys, together with fluorescent in situ hybridization studies, demonstrated the dominance of key thermophilic bacteria and archaea (e.g., Aquificales, Thermotogales, Thermococcales, Archaeoglobales) in the sediments and the presence of a broad spectrum of mostly uncultured crenarchaeota in several vent waters, sediment samples, and geothermal wells. Thermodynamic modeling quantified potential energy yields from aerobic and anaerobic respiration reactions and fermentation reactions. In contrast to their deep-sea counterparts, shallow-sea hydrothermal systems are often characterized by high arsenic concentrations of more than 500-times seawater levels. The arsenic

  3. Cellulase Production Potentials of the Microbial Profile of Some Sugarcane Bagasse Dumping Sites in Ilorin, Nigeria

    Directory of Open Access Journals (Sweden)

    Kamoldeen Abiodun AJIJOLAKEWU

    2013-11-01

    Full Text Available This research work investigated cellulase production potentials of the microbial profile of three sugarcane bagasse dumping sites at Zango area, Ilorin, Nigeria. The microbial isolates were screened for cellulase production with a view to select the best organism for eventual cellulase production. Pour Plate method was used for the isolation and a total of thirteen (13 different organisms including both fungal and bacterial species were isolated and screened. Six (6 fungal isolates identified as Mucor racemosus, Aspergillus niger, Aspergillus flavus, Neurospora sitophilus, Penicillium oxalicum and Penicillium citrinum were isolated, while seven (7 different bacterial species isolated include Clostridium cellobioparum, Clostridium thermocellum,Bacillus subtilis, Bacillus pumillus, Lactobacillus spp, Pseudomonas flavescens and Serratia spp. Generally, bacterial isolates were more in abundance than fungal species. However; fungal isolates were constant and were isolated through the experimental period of three weeks. All the isolates showed cellulase production potential in varying degrees as reflected in the clearance zone around their colonies. Fungal isolates produced more cellulase than the bacterial isolates. Mucor racemosus had the highest clearance zone (75.0 mm among the fungal isolates while Clostridium cellobioparum (35.0 mm were the best producer among bacterial isolates. The least producer among fungal isolates, Penicillium citrinum (40.0 mm, is a little more than the bacterial cellulase producer (35.0 mm and is far greater than the least bacterium Serratia spp (14.0 mm.

  4. Streamlining genomes: toward the generation of simplified and stabilized microbial systems

    NARCIS (Netherlands)

    Leprince, A.; Passel, van M.W.J.; Martins Dos Santos, V.A.P.

    2012-01-01

    At the junction between systems and synthetic biology, genome streamlining provides a solid foundation both for increased understanding of cellular circuitry, and for the tailoring of microbial chassis towards innovative biotechnological applications. Iterative genomic deletions (targeted and

  5. Product quality and microbial dynamics during vermicomposting and maturation of compost from pig manure.

    Science.gov (United States)

    Villar, Iria; Alves, David; Mato, Salustiano

    2017-11-01

    This research evaluates, through microbial dynamics, the use of earthworms Eisenia andrei for maturation of pre-composted pig manure in comparison with maturation under static conditions and with vermicomposting of fresh pig manure. Therefore, two substrates were used (fresh and pre-composted pig manure) and four treatments were developed: fresh manure vermicomposting, control of fresh manure without earthworms, pre-composting followed by vermicomposting and static maturation of pre-composted manure. In order to determine the microbial dynamics, the enzymatic activities and profiles of phospholipid fatty acids (PLFAs) were evaluated over a 112-days period. Physicochemical and biological parameters of the obtained products were also analyzed. The presence of earthworms significantly reduced (pquality values, it is necessary to optimize the vermicompost aging phase period to improve the stability. Static maturation presented stability on microbial dynamics that indicated a slow degradation of organic compounds so that, maturation of pre-composted manure through vermicomposting is better option. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Bioremediation of soil heavily contaminated with crude oil and its products: composition of the microbial consortium

    Directory of Open Access Journals (Sweden)

    JELENA S. MILIĆ

    2009-04-01

    Full Text Available Bioremediation, a process that utilizes the capability of microorganism to degrade toxic waste, is emerging as a promising technology for the treatment of soil and groundwater contamination. The technology is very effective in dealing with petroleum hydrocarbon contamination. The aim of this study was to examine the composition of the microbial consortium during the ex situ experiment of bioremediation of soil heavily contaminated with crude oil and its products from the Oil Refinery Pančevo, Serbia. After a 5.5-month experiment with biostimulation and bioventilation, the concentration of the total petroleum hydrocarbons (TPH had been reduced from 29.80 to 3.29 g/kg (89 %. In soil, the dominant microorganism population comprised Gram-positive bacteria from actinomycete-Nocardia group. The microorganisms which decompose hydrocarbons were the dominant microbial population at the end of the process, with a share of more than 80 % (range 107 CFU/g. On the basis of the results, it was concluded that a stable microbial community had been formed after initial fluctuations.

  7. Microbial conversion of food wastes for biofertilizer production with thermophilic lipolytic microbes

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Shu-Hsien; Yang, Shang-Shyng [Institute of Microbiology and Biochemistry, National Taiwan University, Taipei 10617, (Taiwan); Liu, Ching-Piao [Department of Biological Science and Technology, Meiho Institute of Technology, Pingtung 91201, (Taiwan)

    2007-05-15

    Food waste is approximately one quarter of the total garbage in Taiwan. To investigate the feasibility of microbial conversion of food waste to multiple functional biofertilizer, food waste was mixed with bulking materials, inoculated with thermophilic and lipolytic microbes and incubated at 50{sup o}C in a mechanical composter. Microbial inoculation enhanced the degradation of food wastes, increased the total nitrogen and the germination rate of alfalfa seed, shortened the maturity period and improved the quality of biofertilizer. In food waste inoculated with thermophilic and lipolytic Brevibacillus borstelensis SH168 for 28 days, total nitrogen increased from 2.01% to 2.10%, ash increased from 24.94% to 29.21%, crude fat decreased from 4.88% to 1.34% and the C/N ratio decreased from 18.02 to 17.65. Each gram of final product had a higher population of thermophilic microbes than mesophilic microbes. Microbial conversion of food waste to biofertilizer is a feasible and potential technology in the future to maintain the natural resources and to reduce the impact on environmental quality. (author)

  8. Products in fusion systems

    DEFF Research Database (Denmark)

    Henke, Ellen

    2013-01-01

    We revisit the notion of a product of a normal subsystem with a p-subgroup as defined by Aschbacher (2011) [Asc11, Chapter 8]. In particular, we give a previously unknown, more transparent construction....

  9. Processed Products Database System

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection of annual data on processed seafood products. The Division provides authoritative advice, coordination and guidance on matters related to the collection,...

  10. H2O2 Production in Microbial Electrochemical Cells Fed with Primary Sludge.

    Science.gov (United States)

    Ki, Dongwon; Popat, Sudeep C; Rittmann, Bruce E; Torres, César I

    2017-06-06

    We developed an energy-efficient, flat-plate, dual-chambered microbial peroxide producing cell (MPPC) as an anaerobic energy-conversion technology for converting primary sludge (PS) at the anode and producing hydrogen peroxide (H 2 O 2 ) at the cathode. We operated the MPPC with a 9 day hydraulic retention time in the anode. A maximum H 2 O 2 concentration of ∼230 mg/L was achieved in 6 h of batch cathode operation. This is the first demonstration of H 2 O 2 production using PS in an MPPC, and the energy requirement for H 2 O 2 production was low (∼0.87 kWh/kg H 2 O 2 ) compared to previous studies using real wastewaters. The H 2 O 2 gradually decayed with time due to the diffusion of H 2 O 2 -scavenging carbonate ions from the anode. We compared the anodic performance with a H 2 -producing microbial electrolysis cell (MEC). Both cells (MEC and MPPC) achieved ∼30% Coulombic recovery. While similar microbial communities were present in the anode suspension and anode biofilm for the two operating modes, aerobic bacteria were significant only on the side of the anode facing the membrane in the MPPC. Coupled with a lack of methane production in the MPPC, the presence of aerobic bacteria suggests that H 2 O 2 diffusion to the anode side caused inhibition of methanogens, which led to the decrease in chemical oxygen demand removal. Thus, the Coulombic efficiency was ∼16% higher in the MPPC than in the MEC (64% versus 48%, respectively).

  11. Recent advances and strategies in process and strain engineering for the production of butyric acid by microbial fermentation.

    Science.gov (United States)

    Luo, Hongzhen; Yang, Rongling; Zhao, Yuping; Wang, Zhaoyu; Liu, Zheng; Huang, Mengyu; Zeng, Qingwei

    2018-04-01

    Butyric acid is an important platform chemical, which is widely used in the fields of food, pharmaceutical, energy, etc. Microbial fermentation as an alternative approach for butyric acid production is attracting great attention as it is an environmentally friendly bioprocessing. However, traditional fermentative butyric acid production is still not economically competitive compared to chemical synthesis route, due to the low titer, low productivity, and high production cost. Therefore, reduction of butyric acid production cost by utilization of alternative inexpensive feedstock, and improvement of butyric acid production and productivity has become an important target. Recently, several advanced strategies have been developed for enhanced butyric acid production, including bioprocess techniques and metabolic engineering methods. This review provides an overview of advances and strategies in process and strain engineering for butyric acid production by microbial fermentation. Additionally, future perspectives on improvement of butyric acid production are also proposed. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Improved quantification of farnesene during microbial production from Saccharomyces cerevisiae in two-liquid-phase fermentations

    DEFF Research Database (Denmark)

    Tippmann, Stefan; Nielsen, Jens; Khoomrung, Sakda

    2016-01-01

    Organic solvents are widely used in microbial fermentations to reduce gas stripping effects and capture hydrophobic or toxic compounds. Reliable quantification of biochemical products in these overlays is highly challenging and practically difficult. Here, we present a significant improvement...... carryover could be minimized. Direct quantification of farnesene in dodecane was achieved by GC-FID whereas GC-MS demonstrated to be an excellent technique for identification of known and unknown metabolites. The GC-FID is a suitable technique for direct quantification of farnesene in complex matrices...

  13. Reconsidering rumen microbial consortia to enhance feed efficiency and reduce environmental impact of ruminant livestock production systems Consórcios microbianos no rúmen para melhorar a eficiência alimentar e reduzir o impacto ambiental dos sistemas de produção animal

    Directory of Open Access Journals (Sweden)

    Jeffrey Lynn Firkins

    2010-07-01

    Full Text Available Because cultivation-based approaches to assess rumen microbiology assess only the minority of microbial groups and can miss opportunities to assess important functions, molecular-based approaches have flourished in microbial ecology and have been adapted to the rumen. Current approaches are described herein, specifically for a robust adaptation to nutrition studies or future opportunities. These included automated profiling techniques, density gradient gel electrophoresis, and future adaption of microarray or high-throughput sequencing technologies. Based on current knowledge, a more holistic approach is needed to describe various functional groups of microbes within the context of how they influence, and are influenced by, the whole consortium (combination of microbial groups. Such a perspective is applied to issues related to increasing fiber digestibility when feeding concentrate or unsaturated fats to high producing beef and dairy cattle. These same microbial populations should help to provide growth factors for fibrolytic bacteria while competing against the hyperammonia-producing bacteria such that there would be less need for excessive rumen-degraded protein as a safety factor. Moreover, these same dietary conditions influence the processes of biohydrogenation and methanogenesis. After accounting for population structures of bacteria, protozoa, methanogenic archaea, and even fungi, efforts to integrate molecular-based rumen microbial ecology with dietary conditions should allow us to better explain and therefore predict conditions that will improve feed efficiency and reduce environmental impact of ruminant production systems.Técnicas tradicionais de identificação de microorganismos ruminais utilizando metodologias de cultivo conseguem identificar um pequeno grupo de bactérias. Técnicas de identificação molecular têm sido amplamente utilizadas em ecossistemas microbiológicos e adaptadas em estudos com ruminantes. Fundamentado no

  14. Chemical diversity of microbial volatiles and their potential for plant growth and productivity

    Directory of Open Access Journals (Sweden)

    CHIDANANDA NAGAMANGALA KANCHISWAMY

    2015-03-01

    Full Text Available Microbial volatile organic compounds (MVOCs are produced by a wide array of microorganisms ranging from bacteria to fungi. A growing body of evidence indicates that MVOCs are ecofriendly and can be exploited as a cost-effective sustainable strategy for use in agricultural practice as agents that enhance plant growth, productivity and disease resistance. As naturally occurring chemicals, MVOCs have potential as possible alternatives to harmful pesticides, fungicides and bactericides as well as genetic modification. Recent studies performed under open field conditions demonstrate that efficiently adopting MVOCs may contribute to sustainable crop protection and production. We review here the chemical diversity of MVOCs and their potential physiological effects on crops and analyze potential and actual limitations for MVOC use as a sustainable strategy for improving productivity and reducing pesticide use.

  15. Production of a generic microbial feedstock for lignocellulose biorefineries through sequential bioprocessing.

    Science.gov (United States)

    Chang, Chen-Wei; Webb, Colin

    2017-03-01

    Lignocellulosic materials, mostly from agricultural and forestry residues, provide a potential renewable resource for sustainable biorefineries. Reducing sugars can be produced only after a pre-treatment stage, which normally involves chemicals but can be biological. In this case, two steps are usually necessary: solid-state cultivation of fungi for deconstruction, followed by enzymatic hydrolysis using cellulolytic enzymes. In this research, the utilisation of solid-state bioprocessing using the fungus Trichoderma longibrachiatum was implemented as a simultaneous microbial pretreatment and in-situ enzyme production method for fungal autolysis and further enzyme hydrolysis of fermented solids. Suspending the fermented solids in water at 50°C led to the highest hydrolysis yields of 226mg/g reducing sugar and 7.7mg/g free amino nitrogen (FAN). The resultant feedstock was shown to be suitable for the production of various products including ethanol. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Recent progress in synthetic biology for microbial production of C3-C10 alcohols

    Directory of Open Access Journals (Sweden)

    Edna N. Lamsen

    2012-06-01

    Full Text Available The growing need to address current energy and environmental problems has sparked an interest in developing improved biological methods to produce liquid fuels from renewable sources. While microbial ethanol production is well established, higher chain alcohols possess chemical properties that are more similar to gasoline. Unfortunately, these alcohols (except 1-butanol are not produced efficiently in natural microorganisms, and thus economical production in industrial volumes remains a challenge. Synthetic biology, however, offers additional tools to engineer synthetic pathways in user-friendly hosts to help increase titers and productivity of these advanced biofuels. This review concentrates on recent developments in synthetic biology to produce higher-chain alcohols as viable renewable replacements for traditional fuel.

  17. Application of Microbial Products to Promote Electrodialytic Remediation of Heavy Metal Contaminated Soil

    DEFF Research Database (Denmark)

    Jensen, Pernille Erland

    2006-01-01

    remediation (EDR) method for efficient treatment of Pb-contaminated soil by application of microbial products. Mobilization of Pb in soil by complexation with exopolymers and whole or disintegrated cells was investigated in column studies. Although exopolymers were previously shown to mobilize Pb in soil...... as potential methods for promotion of EDR of Pb contaminated soil. By these methods mobilization of Pb would occur due to complexation with much smaller substances than the previously examined and rejected exopolymers, why they were considered more efficient for mobilization of Pb in an electric current field...... also rejected, primarily due to the insufficient concentrations produced by microorganisms in general and the unrealistic high costs of industrially produced siderophores in relation to the low value of the product to be treated. Furthermore no detection of siderophore production was possible during...

  18. Valorization of By-Products from Palm Oil Mills for the Production of Generic Fermentation Media for Microbial Oil Synthesis.

    Science.gov (United States)

    Tsouko, Erminda; Kachrimanidou, Vasiliki; Dos Santos, Anderson Fragoso; do Nascimento Vitorino Lima, Maria Eduarda; Papanikolaou, Seraphim; de Castro, Aline Machado; Freire, Denise Maria Guimarães; Koutinas, Apostolis A

    2017-04-01

    This study demonstrates the production of a generic nutrient-rich feedstock using by-product streams from palm oil production that could be used as a substitute for commercial fermentation supplements. Solid-state fermentations of palm kernel cake (PKC) and palm-pressed fiber (PPF) were conducted in tray bioreactors and a rotating drum bioreactor by the fungal strain Aspergillus oryzae for the production of crude enzymes. The production of protease was optimized (319.3 U/g) at an initial moisture content of 55 %, when PKC was used as the sole substrate. The highest free amino nitrogen (FAN) production (5.6 mg/g) obtained via PKC hydrolysis using the crude enzymes produced via solid-state fermentation was achieved at 50 °C. Three initial PKC concentrations (48.7, 73.7, and 98.7 g/L) were tested in hydrolysis experiments, leading to total Kjeldahl nitrogen to FAN conversion yields up to 27.9 %. Sequential solid-state fermentation followed by hydrolysis was carried out in the same rotating drum bioreactor, leading to the production of 136.7 U/g of protease activity during fermentation and 196.5 mg/L of FAN during hydrolysis. Microbial oil production was successfully achieved with the oleaginous yeast strain Lipomyces starkeyi DSM 70296 cultivated on the produced PKC hydrolysate mixed with commercial carbon sources, including glucose, xylose, mannose, galactose, and arabinose.

  19. A critical revisit of the key parameters used to describe microbial electrochemical systems

    International Nuclear Information System (INIS)

    Sharma, Mohita; Bajracharya, Suman; Gildemyn, Sylvia; Patil, Sunil A.; Alvarez-Gallego, Yolanda; Pant, Deepak; Rabaey, Korneel; Dominguez-Benetton, Xochitl

    2014-01-01

    Graphical abstract: - Abstract: Many microorganisms have the innate capability to discharge and/or receive electrons to and from solid state materials such as electrodes. This ability is now used towards innovative processes in wastewater treatment, power generation, production of fuels and biochemicals, bioremediation, desalination and resource recovery, among others. Despite being a dynamic field in science and technology, significant challenges remain towards industrial implementation which include representation of judicious performance indicators. This critical review outlines the progress in current density evaluated per projected surface area of electrodes, the most wide-spread performance indicator. It also proposes guidelines to correct current and exchange current per porous surface area, biofilm covered area, electrochemically- or bioelectrochemically- active surface area, of the electrodes. Recommendations for indicators to describe the environmental and electrochemical robustness of electrochemically-active biofilms are portrayed, including preservation of the predominant functionality as well as electrochemical mechanistic and phenomenological features. A few additional key elements for industrial processing are depicted. Whereas Microbial Fuel Cells (MFCs) are the main focus, some important parameters for reporting on cathodic bioproduction performance are also discussed. This critical revision aims to provide key parameters to compare the whole spectrum of microbial electrochemical systems in a consistent way

  20. Microbial production of volatile sulphur compounds in the large intestine of pigs fed two different diets.

    Science.gov (United States)

    Poulsen, H V; Jensen, B B; Finster, K; Spence, C; Whitehead, T R; Cotta, M A; Canibe, N

    2012-07-01

      To investigate the production of volatile sulphur compounds (VSC) in the segments of the large intestine of pigs and to assess the impact of diet on this production.   Pigs were fed two diets based on either wheat and barley (STD) or wheat and dried distillers grains with solubles (DDGS). Net production of VSC and potential sulphate reduction rate (SRR) (sulphate saturated) along the large intestine were determined by means of in vitro incubations. The net production rate of hydrogen sulphide and potential SRR increased from caecum towards distal colon and were significantly higher in the STD group. Conversely, the net methanethiol production rate was significantly higher in the DDGS group, while no difference was observed for dimethyl sulphide. The number of sulphate-reducing bacteria and total bacteria were determined by quantitative PCR and showed a significant increase along the large intestine, whereas no diet-related differences were observed.   VSC net production varies widely throughout the large intestine of pigs and the microbial processes involved in this production can be affected by diet.   This first report on intestinal production of all VSC shows both spatial and dietary effects, which are relevant to both bowel disease- and odour mitigation research. © 2012 The Authors. Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.

  1. Status of microbial diversity in agroforestry systems in Tamil Nadu, India.

    Science.gov (United States)

    Radhakrishnan, Srinivasan; Varadharajan, Mohan

    2016-06-01

    Soil is a complex and dynamic biological system. Agroforestry systems are considered to be an alternative land use option to help and prevent soil degradation, improve soil fertility, microbial diversity, and organic matter status. An increasing interest has emerged with respect to the importance of microbial diversity in soil habitats. The present study deals with the status of microbial diversity in agroforestry systems in Tamil Nadu. Eight soil samples were collected from different fields in agroforestry systems in Cuddalore, Villupuram, Tiruvanamalai, and Erode districts, Tamil Nadu. The number of microorganisms and physico-chemical parameters of soils were quantified. Among different microbial population, the bacterial population was recorded maximum (64%), followed by actinomycetes (23%) and fungi (13%) in different samples screened. It is interesting to note that the microbial population was positively correlated with the physico-chemical properties of different soil samples screened. Total bacterial count had positive correlation with soil organic carbon (C), moisture content, pH, nitrogen (N), and micronutrients such as Iron (Fe), copper (Cu), and zinc (Zn). Similarly, the total actinomycete count also showed positive correlations with bulk density, moisture content, pH, C, N, phosphorus (P), potassium (K), calcium (Ca), copper (Cu), magnesium (Mg), manganese (Mn), and zinc (Zn). It was also noticed that the soil organic matter, vegetation, and soil nutrients altered the microbial community under agroforestry systems. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Seasonal Variation on Microbial Community and Methane Production during Anaerobic Digestion of Cattle Manure in Brazil.

    Science.gov (United States)

    Resende, Juliana Alves; Godon, Jean-Jacques; Bonnafous, Anaïs; Arcuri, Pedro Braga; Silva, Vânia Lúcia; Otenio, Marcelo Henrique; Diniz, Cláudio Galuppo

    2016-04-01

    Anaerobic digestion is an alternative method for the treatment of animal manure and wastewater. The anaerobic bioconversion of biomass requires a multi-step biological process, including microorganisms with distinct roles. The diversity and composition of microbial structure in pilot-scale anaerobic digestion operating at ambient temperature in Brazil were studied. Influence of the seasonal and temporal patterns on bacterial and archaeal communities were assessed by studying the variations in density, dynamic and diversity and structure. The average daily biogas produced in the summer and winter months was 18.7 and 16 L day(-1), respectively, and there was no difference in the average methane yield. Quantitative PCR analysis revealed that no differences in abundances and dynamics were found for bacterial communities and the total number of Archaea in different seasons. Analysis of bacterial clone libraries revealed a predominance of Firmicutes (54.5 %/summer and 46.7 %/winter) and Bacteroidetes (31.4 %/summer and 44.4 %/winter). Within the Archaea, the phylum Euryarchaeota was predominant in both digesters. Phylogenetic distribution showed changes in percentage between the phyla identified, but no alterations were recorded in the quality and amount of produced methane or community dynamics. The results may suggest that redundancy of microbial groups may have occurred, pointing to a more complex microbial community in the ecosystem related to this ambient temperature system.

  3. Degradation of corn stalk by the composite microbial system of MC1

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The composite microbial system of MC1 was used to degrade corn stalk in order to determine properties of the degraded products as well as bacterial composition of MC1. Results indicated that the pH of the fermentation broth was typical of lignocellulose degradatioin by MC1, decreasing in the early phase and increasing in later stages of the degradation. The microbial biomass peaked on the day 3 after degradation. The MC1 effeciently degraded the corn stalk by nearly 70% during which its cellulose content decreased by 71.2%, hemicellulose by 76.5% and lignin by 24.6%. The content of water-soluble carbohydrates (WSC) in the fermentation broth increased progressively during the first three days, and decreased thereafter, suggesting an accumulation of WSC in the early phase of the degradation process. Total levels of various volatile products peaked in the third day after degradation , and 7 types of volatile products were detected in the fermentation broth. These were ethanol, acetic acid, 1,2-ethanediol, propanoic acid, butanoic acid, 3-methyl-butanoic acid and glycerine. Six major compounds were quantitatively analysed and the contents of each compound were ethanol (0.584 g/L), acetic acid (0.735 g/L), 1,2-ethanediol (0.772 g/L), propanoic acid (0.026 g/L), butanoic acid (0.018 g/L) and glycerine (4.203 g/L). Characterization of bacterial cells collected from the culture solution, based on 16S rDNA PCR-DGGE analysis of DNAs, showed that the composition of bacterial community in MC1 coincided basically with observations from previous studies. This indicated that the structure of MC1 is very stable during degradation of different lignocellulose materials.

  4. Gradients in microbial methanol uptake: productive coastal upwelling waters to oligotrophic gyres in the Atlantic Ocean

    Science.gov (United States)

    Dixon, Joanna L; Sargeant, Stephanie; Nightingale, Philip D; Colin Murrell, J

    2013-01-01

    Methanol biogeochemistry and its importance as a carbon source in seawater is relatively unexplored. We report the first microbial methanol carbon assimilation rates (k) in productive coastal upwelling waters of up to 0.117±0.002 d−1 (∼10 nmol l−1 d−1). On average, coastal upwelling waters were 11 times greater than open ocean northern temperate (NT) waters, eight times greater than gyre waters and four times greater than equatorial upwelling (EU) waters; suggesting that all upwelling waters upon reaching the surface (⩽20 m), contain a microbial population that uses a relatively high amount of carbon (0.3–10 nmol l−1 d−1), derived from methanol, to support their growth. In open ocean Atlantic regions, microbial uptake of methanol into biomass was significantly lower, ranging between 0.04–0.68 nmol l−1 d−1. Microbes in the Mauritanian coastal upwelling used up to 57% of the total methanol for assimilation of the carbon into cells, compared with an average of 12% in the EU, and 1% in NT and gyre waters. Several methylotrophic bacterial species were identified from open ocean Atlantic waters using PCR amplification of mxaF encoding methanol dehydrogenase, the key enzyme in bacterial methanol oxidation. These included Methylophaga sp., Burkholderiales sp., Methylococcaceae sp., Ancylobacter aquaticus, Paracoccus denitrificans, Methylophilus methylotrophus, Methylobacterium oryzae, Hyphomicrobium sp. and Methylosulfonomonas methylovora. Statistically significant correlations for upwelling waters between methanol uptake into cells and both chlorophyll a concentrations and methanol oxidation rates suggest that remotely sensed chlorophyll a images, in these productive areas, could be used to derive total methanol biological loss rates, a useful tool for atmospheric and marine climatically active gas modellers, and air–sea exchange scientists. PMID:23178665

  5. Geochemical characterization of the hydrous pyrolysis products from a recent cyanobacteria-dominated microbial mat

    Energy Technology Data Exchange (ETDEWEB)

    Franco, N.; Mendoça-Filho, J.G.; Silva, T.F.; Stojanovic, K.; Fontana, L.F.; Carvalhal-Gomes, S.B.V.; Silva, F.S.; Furukawa, G.G.

    2016-07-01

    Hydrous pyrolysis experiments were performed on a recent microbial mat sample from Lagoa Vermelha, Brazil, to determine whether crude oil can be generated and expelled during artificial maturation of the Organic Matter (OM). The experiments were conducted at 280ºC, 330ºC and 350ºC during 20h. Two types of liquid pyrolysis products, assigned as free oil and bitumen, were isolated and analyzed. Free oil represents free organic phase released by hydrous pyrolysis, whereas bitumen was obtained by extraction from the solid pyrolysis residue with dichloromethane. Changes in the OM maturity were determined using Rock-Eval parameters and biomarker maturity ratios of original sample and pyrolysis products. Biomarker compositions of original sample extract and liquid pyrolysates were used for determination of dominant bacterial source. The yields of free oil and bitumen showed that a microbial mat OM has a high liquid hydrocarbons generation potential. Rock-Eval maturity parameters, biopolymer and biomarker compositions indicate a significant increase of the OM maturity during hydrous pyrolysis. At 280ºC the release of free, adsorbed and occluded compounds was observed; however, without a cracking of the OM. At 330ºC the generation of bitumen and free oil is mostly related to the OM cracking. The highest yield of free oil was recorded at this temperature. Distribution of biomarkers in the extract of original sample and liquid pyrolysates confirms cyanobacteria-dominated microbial mats, whereas the identification of long chain n-alkane series, with maximum at C26, and prominent C30 hop-17(21)-ene additionally suggest the presence of sulfate reducing bacteria. (Author)

  6. Automated plant, production management system

    Science.gov (United States)

    Aksenova, V. I.; Belov, V. I.

    1984-12-01

    The development of a complex of tasks for the operational management of production (OUP) within the framework of an automated system for production management (ASUP) shows that it is impossible to have effective computations without reliable initial information. The influence of many factors involving the production and economic activity of the entire enterprise upon the plan and course of production are considered. It is suggested that an adequate model should be available which covers all levels of the hierarchical system: workplace, section (bridgade), shop, enterprise, and the model should be incorporated into the technological sequence of performance and there should be provisions for an adequate man machine system.

  7. Microbial Oxidation of Hg(0) - Its Effect on Hg Stable Isotope Fractionation and Methylmercury Production

    Energy Technology Data Exchange (ETDEWEB)

    Yee, Nathan [Rutgers Univ., New Brunswick, NJ (United States); Barkay, Tamar [Rutgers Univ., New Brunswick, NJ (United States); Reinfelder, John [Rutgers Univ., New Brunswick, NJ (United States)

    2016-06-28

    relationship between Hg concentrations and rates of denitrification in enrichment cultures. In part III of our project, we examined in more detail the effects of microbial interactions on Hg transformations. We discovered that both sulfate reducing and iron reducing bacteria coexist in freshwater sediments and both microbial groups contribute to mercury methylation. We showed that mercury methylation by sulfate reducing and iron reducing bacteria are temporally and spatially separated processes. We also discovered that methanogens can methylate mercury. We showed that Methanospirillum hungatei JF-1 methylated Hg at comparable rates, but with higher yields, than those observed for sulfate-reducing bacteria and iron-reducing bacteria. Finally, we demonstrated that syntrophic interactions between different microbial groups increase mercury methylation rates. We showed that Hg methylation rates are stimulated via inter-species hydrogen and acetate transfer (i) from sulfate-reducing bacteria to methanogens and (ii) from fermenters to the sulfate-reducing bacteria. In part IV of the project, we studied Hg bioavailability and Hg isotope fractionation. We demonstrated that thiol-bound Hg is bioavailable to mercury resistant bacteria. We found that uptake of Hg from Hg-glutathione and Hg-cysteine complexes does not require functioning glutathione and cystine/cysteine transport systems. We demonstrated that a wide range of methylmercury complexes (e.g. MeHgOH, MeHg-cysteine, and MeHg-glutathione) are bioavailable to mercury resistant bacteria. The rate of MeHg demethylation varies more between different species of mercury resistant bacteria than among MeHg complexes. We showed that microbial demethylation of MeHg depends more on the species of microorganism than on the types and relative concentrations of thiols or other MeHg ligands present. Finally, we demonstrated that Hg methylation by Geobacter sulfurreducens PCA and Desulfovibrio desulfuricans ND132 imparts mass

  8. GLOBAL PRODUCTION SYSTEM

    Directory of Open Access Journals (Sweden)

    Dumitru FILIPEANU

    2016-07-01

    Full Text Available The most significant transformations that globalization produces occur in production. Since the '60s, a new division of labor has made its presence felt in the world, arising from the "de-industrialization" of the developed and transfer production capacity of resource-intensive industries and pollutants from these countries to the developing world. "Dislocation" industry had the interim foreign direct investment made in the new industrialized countries, the latter becoming, in turn, sources of direct foreign investment, taking its capital in other countries in developing handsets. Currently, FDI destination is no longer a priority in developing countries, yet they are increasingly leaning towards the developed countries, due to the attractiveness offered by their economies.

  9. Modular spectral imaging system for discrimination of pigments in cells and microbial communities.

    Science.gov (United States)

    Polerecky, Lubos; Bissett, Andrew; Al-Najjar, Mohammad; Faerber, Paul; Osmers, Harald; Suci, Peter A; Stoodley, Paul; de Beer, Dirk

    2009-02-01

    Here we describe a spectral imaging system for minimally invasive identification, localization, and relative quantification of pigments in cells and microbial communities. The modularity of the system allows pigment detection on spatial scales ranging from the single-cell level to regions whose areas are several tens of square centimeters. For pigment identification in vivo absorption and/or autofluorescence spectra are used as the analytical signals. Along with the hardware, which is easy to transport and simple to assemble and allows rapid measurement, we describe newly developed software that allows highly sensitive and pigment-specific analyses of the hyperspectral data. We also propose and describe a number of applications of the system for microbial ecology, including identification of pigments in living cells and high-spatial-resolution imaging of pigments and the associated phototrophic groups in complex microbial communities, such as photosynthetic endolithic biofilms, microbial mats, and intertidal sediments. This system provides new possibilities for studying the role of spatial organization of microorganisms in the ecological functioning of complex benthic microbial communities or for noninvasively monitoring changes in the spatial organization and/or composition of a microbial community in response to changing environmental factors.

  10. Microbial-processing of fruit and vegetable wastes for production of vital enzymes and organic acids: Biotechnology and scopes.

    Science.gov (United States)

    Panda, Sandeep K; Mishra, Swati S; Kayitesi, Eugenie; Ray, Ramesh C

    2016-04-01

    Wastes generated from fruits and vegetables are organic in nature and contribute a major share in soil and water pollution. Also, green house gas emission caused by fruit and vegetable wastes (FVWs) is a matter of serious environmental concern. This review addresses the developments over the last one decade on microbial processing technologies for production of enzymes and organic acids from FVWs. The advances in genetic engineering for improvement of microbial strains in order to enhance the production of the value added bio-products as well as the concept of zero-waste economy have been briefly discussed. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Minimal RED Cell Pairs Markedly Improve Electrode Kinetics and Power Production in Microbial Reverse Electrodialysis Cells

    KAUST Repository

    Cusick, Roland D.

    2013-12-17

    Power production from microbial reverse electrodialysis cell (MRC) electrodes is substantially improved compared to microbial fuel cells (MFCs) by using ammonium bicarbonate (AmB) solutions in multiple RED cell pair stacks and the cathode chamber. Reducing the number of RED membranes pairs while maintaining enhanced electrode performance could help to reduce capital costs. We show here that using only a single RED cell pair (CP), created by operating the cathode in concentrated AmB, dramatically increased power production normalized to cathode area from both acetate (Acetate: from 0.9 to 3.1 W/m 2-cat) and wastewater (WW: 0.3 to 1.7 W/m2), by reducing solution and charge transfer resistances at the cathode. A second RED cell pair increased RED stack potential and reduced anode charge transfer resistance, further increasing power production (Acetate: 4.2 W/m2; WW: 1.9 W/m2). By maintaining near optimal electrode power production with fewer membranes, power densities normalized to total membrane area for the 1-CP (Acetate: 3.1 W/m2-mem; WW: 1.7 W/m2) and 2-CP (Acetate: 1.3 W/m2-mem; WW: 0.6 W/m2) reactors were much higher than previous MRCs (0.3-0.5 W/m2-mem with acetate). While operating at peak power, the rate of wastewater COD removal, normalized to reactor volume, was 30-50 times higher in 1-CP and 2-CP MRCs than that in a single chamber MFC. These findings show that even a single cell pair AmB RED stack can significantly enhance electrical power production and wastewater treatment. © 2013 American Chemical Society.

  12. Minimal RED Cell Pairs Markedly Improve Electrode Kinetics and Power Production in Microbial Reverse Electrodialysis Cells

    KAUST Repository

    Cusick, Roland D.; Hatzell, Marta; Zhang, Fang; Logan, Bruce E.

    2013-01-01

    Power production from microbial reverse electrodialysis cell (MRC) electrodes is substantially improved compared to microbial fuel cells (MFCs) by using ammonium bicarbonate (AmB) solutions in multiple RED cell pair stacks and the cathode chamber. Reducing the number of RED membranes pairs while maintaining enhanced electrode performance could help to reduce capital costs. We show here that using only a single RED cell pair (CP), created by operating the cathode in concentrated AmB, dramatically increased power production normalized to cathode area from both acetate (Acetate: from 0.9 to 3.1 W/m 2-cat) and wastewater (WW: 0.3 to 1.7 W/m2), by reducing solution and charge transfer resistances at the cathode. A second RED cell pair increased RED stack potential and reduced anode charge transfer resistance, further increasing power production (Acetate: 4.2 W/m2; WW: 1.9 W/m2). By maintaining near optimal electrode power production with fewer membranes, power densities normalized to total membrane area for the 1-CP (Acetate: 3.1 W/m2-mem; WW: 1.7 W/m2) and 2-CP (Acetate: 1.3 W/m2-mem; WW: 0.6 W/m2) reactors were much higher than previous MRCs (0.3-0.5 W/m2-mem with acetate). While operating at peak power, the rate of wastewater COD removal, normalized to reactor volume, was 30-50 times higher in 1-CP and 2-CP MRCs than that in a single chamber MFC. These findings show that even a single cell pair AmB RED stack can significantly enhance electrical power production and wastewater treatment. © 2013 American Chemical Society.

  13. Restructuring upstream bioprocessing: technological and economical aspects for production of a generic microbial feedstock from wheat.

    Science.gov (United States)

    Koutinas, A A; Wang, R; Webb, C

    2004-03-05

    Restructuring and optimization of the conventional fermentation industry for fuel and chemical production is necessary to replace petrochemical production routes. Guided by this concept, a novel biorefinery process has been developed as an alternative to conventional upstream processing routes, leading to the production of a generic fermentation feedstock from wheat. The robustness of Aspergillus awamori as enzyme producer is exploited in a continuous fungal fermentation on whole wheat flour. Vital gluten is extracted as an added-value byproduct by the conventional Martin process from a fraction of the overall wheat used. Enzymatic hydrolysis of gluten-free flour by the enzyme complex produced by A. awamori during fermentation produces a liquid stream rich in glucose (320 g/L). Autolysis of fungal cells produces a micronutrient-rich solution similar to yeast extract (1.6 g/L nitrogen, 0.5 g/L phosphorus). The case-specific combination of these two liquid streams can provide a nutrient-complete fermentation medium for a spectrum of microbial bioconversions for the production of such chemicals as organic acids, amino acids, bioethanol, glycerol, solvents, and microbial biodegradable plastics. Preliminary economic analysis has shown that the operating cost required to produce the feedstock is dependent on the plant capacity, cereal market price, presence and market value of added-value byproducts, labor costs, and mode of processing (batch or continuous). Integration of this process in an existing fermentation plant could lead to the production of a generic feedstock at an operating cost lower than the market price of glucose syrup (90% to 99% glucose) in the EU, provided that the plant capacity exceeds 410 m(3)/day. Further process improvements are also suggested. Copyright 2004 Wiley Periodicals, Inc.

  14. Impact of different antibiotics on methane production using waste-activated sludge: mechanisms and microbial community dynamics.

    Science.gov (United States)

    Mustapha, Nurul Asyifah; Sakai, Kenji; Shirai, Yoshihito; Maeda, Toshinari

    2016-11-01

    Anaerobic digestion is an effective method for reducing the by-product of waste-activated sludge (WAS) from wastewater treatment plants and for producing bioenergy from WAS. However, only a limited number of studies have attempted to improve anaerobic digestion by targeting the microbial interactions in WAS. In this study, we examined whether different antibiotics positively, negatively, or neutrally influence methane fermentation by evaluating changes in the microbial community and functions in WAS. Addition of azithromycin promoted the microbial communities related to the acidogenic and acetogenic stages, and a high concentration of soluble proteins and a high activity of methanogens were detected. Chloramphenicol inhibited methane production but did not affect the bacteria that contribute to the hydrolysis, acidogenesis, and acetogenesis digestion stages. The addition of kanamycin, which exhibits the same methane productivity as a control (antibiotic-free WAS), did not affect all of the microbial communities during anaerobic digestion. This study demonstrates the simultaneous functions and interactions of diverse bacteria and methanogenic Archaea in different stages of the anaerobic digestion of WAS. The ratio of Caldilinea, Methanosarcina, and Clostridium may correspond closely to the trend of methane production in each antibiotic. The changes in microbial activities and function by antibiotics facilitate a better understanding of bioenergy production.

  15. Distribution of phototrophic populations and primary production in a microbial mat from the Ebro Delta, Spain.

    Science.gov (United States)

    Martínez-Alonso, Maira; Mir, Joan; Caumette, Pierre; Gaju, Núria; Guerrero, Ricardo; Esteve, Isabel

    2004-03-01

    Microbial mats arising in the sand flats of the Ebro Delta (Tarragona, Spain) were investigated during the summer season, when the community was highly developed. These mats are composed of three pigmented layers of phototrophic organisms, an upper brown layer mainly composed of Lyngbya aestuarii and diatoms, an intermediate green layer of the cyanobacterium Microcoleus chthonoplastes, and an underlying pink layer of a so-far unidentified purple sulfur bacterium. In the photic zone, oxygenic phototrophs constitute about 58% of total photosynthetic biomass, measured as biovolume, and anoxygenic phototrophs represent 42%. Diatoms constitute 11.8% of the oxygenic biomass, M. chthonoplastes 61.2%, and L. aestuarii and coccoid cyanobacteria 20.6 and 6.4%, respectively. In this laminated community, organic matter has an autochthonous origin, and photosynthesis is the most important source of organic carbon. Oxygen production reaches up to 27.2 mmol O(2) m(-2) h(-1), measured at 1000 microE m(-2) s(-1) light intensity, whereas oxidation of sulfide in the light has been calculated to be 18.6 mmol S m(-2) h(-1). This amount represents 26% of the total photosynthetic production in terms of photoassimilated carbon, demonstrating the important role of anoxygenic phototrophs as primary producers in the pink layer of Ebro Delta microbial mats.

  16. Microbial Protein Production and Nitrogen Balance of Local Steer Fed Ammoniated Rice Straws Added

    Directory of Open Access Journals (Sweden)

    H Hindratiningrum

    2009-05-01

    Full Text Available The objective of the experiment was to investigate the kind of energy source feedstuffs on nutrient balance and microbial protein synthesis in local male beef cattle fed with ammoniated rice straws Twenty steers Peranakan Ongole (PO with average age 1-2 years old were used. They were divided 5 groups based on initial body weight as block. Therefore, Completely Randomised Block Design (CBRD was used for this experiment. Data were analysed by analysis variance and continued honestly significant different (HSD to test the differences between means. The result showed that the range MCP and eficiency MCP were 154,61 g/d until 226,54 g/d and 54,08 gMCP/kg DOMR until 62,64 gMCP/kg DOMR. The range of nitrogen balance were 72,28 gram until 111,67 gram. MCP and efficiency MCP were not affected (P>0,05 by the treatments but balance of nitrogen was affected (P<0,05. Diet containing fresh cassava waste as energy source (R2 was lower (P<0,05 than R1 and R4 while between R1,R3 and R4 was similar. This results indicate that feed source of energy (rice brand, wet cassava waste, dry cassava waste and corn can be used in steers with rice straw ensilage as forage. (Animal Production 11(2: 116-121 (2009 Key Words : Microbial protein production, nitrogen balance, rice straw, ensilage

  17. Investigating the possibility of Microbial Production of Mannitol from Waste Bread

    Directory of Open Access Journals (Sweden)

    Vajihe Sadeqi

    2016-07-01

    Full Text Available According to the significant role of sugar alcohols (Polyols in food industries, in the present study the possibility of microbial production of mannitol from bread waste was studied. Microbial growth and amylase production were investigated by five Iranian native strains of Bacillus spp in starch agar and broth. The best strain was selected, and its growth curve was determined. Leuconostoc mesentroides PTCC 1059 was used as a control strain to convert fructose to mannitol. In order to determine the ability of selected strains in converting waste breads into mannitol sugar, a culture medium was prepared from waste of Lavash and Baguette breads. Afterward, the ability to convert starch into fructose by Chemical analysis glucose test was used, and then bio-conversion analysis of fructose to mannitol by HPLC analysis was investigated. HPLC results showed that the Bacillus subtilis and Leuconostoc mesentroides PTCC 1059 had the ability of producing mannitol at a rate of 4.8g/L from fructose 5%, 0.15 g/L from Lavash bread 5%, and 0.2g/L from Baguette bread.

  18. Microbial populations causing off-flavour in recirculated aquaculture systems

    DEFF Research Database (Denmark)

    Lukassen, Mie Bech; Schramm, Edward; Nielsen, Jeppe Lund

    the distribution of geoA in more than 50 European and Brazilian aquaculture systems has allowed us to identify the diversity among geosmin-producing bacteria. The different populations of geosmin-producers were evaluated relative to plant design, environmental and operational parameters in full-scale aquaculture...... systems using multivariate statistics. The influencing parameters identified were subsequently validated by testing their gene expressions in well-controlled pilot scale aquaculture systems. The results show that the geoA gene is a relative well-conserved gene with limited horizontal gene transfer events...... phase. Furthermore, the gene expressions of the individual groups show positive correlations to the organic loading and presence of oxygen. The current study reveals the presence of important populations involved in geosmin production and which parameters are of importance for their presence...

  19. The complicated substrates enhance the microbial diversity and zinc leaching efficiency in sphalerite bioleaching system.

    Science.gov (United States)

    Xiao, Yunhua; Xu, YongDong; Dong, Weiling; Liang, Yili; Fan, Fenliang; Zhang, Xiaoxia; Zhang, Xian; Niu, Jiaojiao; Ma, Liyuan; She, Siyuan; He, Zhili; Liu, Xueduan; Yin, Huaqun

    2015-12-01

    This study used an artificial enrichment microbial consortium to examine the effects of different substrate conditions on microbial diversity, composition, and function (e.g., zinc leaching efficiency) through adding pyrite (SP group), chalcopyrite (SC group), or both (SPC group) in sphalerite bioleaching systems. 16S rRNA gene sequencing analysis showed that microbial community structures and compositions dramatically changed with additions of pyrite or chalcopyrite during the sphalerite bioleaching process. Shannon diversity index showed a significantly increase in the SP (1.460), SC (1.476), and SPC (1.341) groups compared with control (sphalerite group, 0.624) on day 30, meanwhile, zinc leaching efficiencies were enhanced by about 13.4, 2.9, and 13.2%, respectively. Also, additions of pyrite or chalcopyrite could increase electric potential (ORP) and the concentrations of Fe3+ and H+, which were the main factors shaping microbial community structures by Mantel test analysis. Linear regression analysis showed that ORP, Fe3+ concentration, and pH were significantly correlated to zinc leaching efficiency and microbial diversity. In addition, we found that leaching efficiency showed a positive and significant relationship with microbial diversity. In conclusion, our results showed that the complicated substrates could significantly enhance microbial diversity and activity of function.

  20. 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...

  1. Microbial production of xylitol from xylose and L-arabinose: conversion of L-arabitol to xylitol using bacterial oxidoreductases

    Science.gov (United States)

    Microbial production of xylitol, using hemicellulosic biomass such as agricultural residues, is becoming more attractive for reducing its manufacturing cost. L-arabitol is a particular problem to xylitol production from hemicellulosic hydrolyzates that contain both xylose and L-arabinose because it...

  2. Primary production and microbial activity in the euphotic zone of Lake Baikal (Southern Basin) during late winter

    Czech Academy of Sciences Publication Activity Database

    Straškrábová, Viera; Izmest’yeva, L. R.; Maksimova, E. A.; Fietz, S.; Nedoma, Jiří; Borovec, Jakub; Kobanova, G. I.; Shchetinina, E. V.; Pislegina, E. V.

    2005-01-01

    Roč. 46, 1-4 (2005), s. 57-73 ISSN 0921-8181 Grant - others:EU(XE) CONTINENT EVK2-2000-0057 Institutional research plan: CEZ:AV0Z6017912 Keywords : primary production * bacterial production * microbial loop Subject RIV: DA - Hydrology ; Limnology Impact factor: 2.223, year: 2005

  3. Methods for Detecting Microbial Methane Production and Consumption by Gas Chromatography.

    Science.gov (United States)

    Aldridge, Jared T; Catlett, Jennie L; Smith, Megan L; Buan, Nicole R

    2016-04-05

    Methane is an energy-dense fuel but is also a greenhouse gas 25 times more detrimental to the environment than CO 2 . Methane can be produced abiotically by serpentinization, chemically by Sabatier or Fisher-Tropsh chemistry, or biotically by microbes (Berndt et al. , 1996; Horita and Berndt, 1999; Dry, 2002; Wolfe, 1982; Thauer, 1998; Metcalf et al. , 2002). Methanogens are anaerobic archaea that grow by producing methane gas as a metabolic byproduct (Wolfe, 1982; Thauer, 1998). Our lab has developed and optimized three different gas chromatograph-utilizing assays to characterize methanogen metabolism (Catlett et al. , 2015). Here we describe the end point and kinetic assays that can be used to measure methane production by methanogens or methane consumption by methanotrophic microbes. The protocols can be used for measuring methane production or consumption by microbial pure cultures or by enrichment cultures.

  4. Russian Kefir Grains Microbial Composition and Its Changes during Production Process.

    Science.gov (United States)

    Kotova, I B; Cherdyntseva, T A; Netrusov, A I

    2016-01-01

    By combining DGGE-PCR method, classical microbiological analysis and light- and electron microscopic observations, it was found that the composition of microbial communities of central Russia regions kefir grains, starter and kefir drink include bacteria of the genera Lactobacillus, Leuconostoc and Lactococcus, and yeast anamorphs of the genera Saccharomyces, Kazachstania and Gibellulopsis. Fifteen prokaryotic and four eukaryotic pure cultures of microorganisms were isolated and identified from kefir grains. It has been shown that members of the genus Lactobacillus prevailed in kefir grains, whereas strains Leuconostoc pseudomesenteroides and Lactococcus lactis dominated in the final product - kefir drink. Yeasts contained in kefir grains in small amounts have reached a significant number of cells in the process of development of this dairy product. The possibility of reverse cell aggregation has been attempted in a mixed cultivation of all isolated pure cultures, but full formation kefir grains is not yet observed after 1.5 years of observation and reinoculations.

  5. Characterization of soluble microbial products as precursors of disinfection byproducts in drinking water supply.

    Science.gov (United States)

    Liu, Jin-Lin; Li, Xiao-Yan; Xie, Yue-Feng; Tang, Hao

    2014-02-15

    Water pollution by wastewater discharge can cause the problem of disinfection byproducts (DBPs) in drinking water supply. In this study, DBP formation characteristics of soluble microbial products (SMPs) as the main products of wastewater organic biodegradation were investigated. The results show that SMPs can act as DBP precursors in simulated wastewater biodegradation process. Under the experimental conditions, stabilized SMPs had DBPFP (DBP formation potential) yield of around 5.6 μmol mmol(-1)-DOC (dissolved organic carbon) and DBP speciation profile different from that of the conventional precursor, natural organic matter (NOM). SMPs contained polysaccharides, proteins, and humic-like substances, and the latter two groups can act as reactive DBP precursors. SMP fraction with molecular weight of water treatment processes, more efforts are needed to control wastewater-derived DBP problem in water resource management. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Production control system specified quality sausage products

    Directory of Open Access Journals (Sweden)

    A. V. Tokarev

    2016-01-01

    Full Text Available The problem of management of production target in technological system of production of sausages of the set quality is considered in article. Decomposition of technological system is considered. Functions of management are allocated: formation of an optimum compounding of forcemeat, expert analysis of a compounding, laboratory analysis of a compounding and its statement. Information technology of interaction of these functions is offered. The mathematical problem definition of finding of an optimum compounding meat product with use of possible substitutes of ingredients is presented. This mathematical problem is a classical linear programming problem whose solution has the standard program. Since the manufacture of the finished product are various nonlinear effects are taken into account at the present time it is practically impossible, the methodology provided in this operation "Expert analysis of the formulation" and "Laboratory analysis of the finished product." An example of calculating the optimum alternative base recipe "Sausages “Viennese with cheese”" TS 9213-010-40155161-2002. For an alternative formulation demands were made at a cost of meat, the ingredient composition, as well as the final product organoleptic and physic-chemical indicators should comply with regulatory requirements "Sausages “Viennese with cheese”" TS 9213-010-40155161-2002. Indicator acid activity (pH calculated stuffing formulation should be in the range 6.0-6.3. As a partial replacement for the main raw material have been proposed acceptable substitutes. It was necessary to calculate on the basis of the formulation "Sausages “Viennese with cheese”" TS 9213-010-40155161-2002 optimal price and quality alternative formulation. As a result of depreciation of the value of alternative stuffing recipe was 14,5 % when all of the restrictions on the consumer properties. The proposed information technology implemented in the software package "Multi

  7. 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.

  8. Effectiveness of commercial microbial products in enhancing oil degradation in Prince William Sound field plots

    International Nuclear Information System (INIS)

    Venosa, A.D.; Haines, J.R.; Allen, D.M.

    1991-01-01

    In the spring of 1990, previously reported laboratory experiments were conducted on 10 commercial microbial products to test for enhanced biodegradation of weathered crude oil from the Exxon Valdez oil spill. The laboratory tests measured the rate and extent of oil degradation in closed flasks. Weathered oil from the beaches in Alaska and seawater from Prince William Sound were used in the tests. Two of the 10 products were found to provide significantly greater alkane degradation than flasks supplemented with mineral nutrients alone. These two products were selected for further testing on a beach in Prince William Sound. A randomized complete block experiment was designed to compare the effectiveness of these two products in enhancing oil degradation compared to simple fertilizer alone. Four small plots consisting of a no nutrient control, a mineral nutrient plot, and two plots receiving mineral nutrients plus the two products, were laid out on a contaminated beach. These four plots comprised a 'block' of treatments, and this block was replicated four times on the same beach. Triplicate samples of beach sediment were collected at four equally spaced time intervals and analyzed for oil residue weight and alkane hydrocarbon profile changes with time. The objective was to determine if either of the two commercial microbiological products was able to enhance bioremediation of an oil-contaminated beach in Prince William Sound to an extent greater than that achievable by simple fertilizer application. Results indicated no significant differences among the four treatments in the 27-day period of the experiment

  9. Sophorolipids Production by Candida bombicola ATCC 22214 and its Potential Application in Microbial Enhanced Oil Recovery.

    Science.gov (United States)

    Elshafie, Abdulkadir E; Joshi, Sanket J; Al-Wahaibi, Yahya M; Al-Bemani, Ali S; Al-Bahry, Saif N; Al-Maqbali, Dua'a; Banat, Ibrahim M

    2015-01-01

    Biosurfactant production using Candida bombicola ATCC 22214, its characterization and potential applications in enhancing oil recovery were studied at laboratory scale. The seed media and the production media were standardized for optimal growth and biosurfactant production. The production media were tested with different carbon sources: glucose (2%w/v) and corn oil (10%v/v) added separately or concurrently. The samples were collected at 24 h interval up to 120 h and checked for growth (OD660), and biosurfactant production [surface tension (ST) and interfacial tension (IFT)]. The medium with both glucose and corn oil gave better biosurfactant production and reduced both ST and IFT to 28.56 + 0.42mN/m and 2.13 + 0.09mN/m, respectively within 72 h. The produced biosurfactant was quite stable at 13-15% salinity, pH range of 2-12, and at temperature up to 100°C. It also produced stable emulsions (%E24) with different hydrocarbons (pentane, hexane, heptane, tridecane, tetradecane, hexadecane, 1-methylnaphthalene, 2,2,4,4,6,8-heptamethylnonane, light and heavy crude oil). The produced biosurfactant was extracted using ethyl acetate and characterized as a mixture of sophorolipids (SPLs). The potential of SPLs in enhancing oil recovery was tested using core-flooding experiments under reservoir conditions, where additional 27.27% of residual oil (Sor) was recovered. This confirmed the potential of SPLs for applications in microbial enhanced oil recovery.

  10. 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.

  11. Cooled Water Production System,

    Science.gov (United States)

    The invention refers to the field of air conditioning and regards an apparatus for obtaining cooled water . The purpose of the invention is to develop...such a system for obtaining cooled water which would permit the maximum use of the cooling effect of the water -cooling tower.

  12. Microbial Protein Production from Candida tropicalis ATCC13803 in a Submerged Batch Fermentation Process

    Directory of Open Access Journals (Sweden)

    Sahar Golaghaiee

    2017-01-01

    Full Text Available Background and Objective: Microbial protein production can resolve one of the major world challenges, i.e. lack of protein sources. Candida tropicalis growth was investigated to specify a medium to reach the highest cell proliferation and protein production.Material and Methods: Fractional factorial design and the index of signal to noise ratio were applied for optimization of microbial protein production. Optimization process was conducted based on the experimental results of Taguchi approach designs. Fermentationwas performed at 25oC and the agitation speed of 300 rpm for 70 h. Ammonium sulfate, iron sulfate, glycine and glucose concentrations were considered as process variables. Optimization of the culture medium composition was conducted in order to obtain the highest cell biomass concentration and protein content. Experiment design was performed based on the Taguchi approach and L-16 orthogonal arrays using Qualitek-4 software.Results and Conclusion: Maximum biomass of 8.72 log (CFU ml-1 was obtained using the optimized medium with 0.3, 0.15, 2 and 80 g l-1 of ammonium sulfate, iron sulfate, glycine and glucose, respectively. Iron sulfate and ammonium sulfate with 41.76% (w w-1 and 35.27% (w w-1 contributions, respectively, were recognized as the main components for cell growth. Glucose and glycine with 17.12% and 5.86% (w w-1 contributions,respectively, also affected cell production. The highest interaction severity index of +54.16% was observed between glycine and glucose while the least one of +0.43% was recorded for ammonium sulfate and glycine. A deviation of 7% between the highestpredicted cell numbers and the experimented count confirms the suitability of the applied statistical method. High protein content of 52.16% (w w-1 as well as low fat and nucleic acids content suggest that Candida tropicalis is a suitable case for commercial processes.Conflict of interest: The authors declare that there is no conflict of interest.

  13. Enhancement of electricity production by graphene oxide in soil microbial fuel cells and plant microbial fuel cells

    Directory of Open Access Journals (Sweden)

    Yuko eGoto

    2015-04-01

    Full Text Available The effects of graphene oxide (GO on electricity generation in soil microbial fuel cells (SMFCs and plant microbial fuel cell (PMFCs were investigated. GO at concentrations ranging from 0 to 1.9 g•kg-1 was added to soil and reduced for 10 days under anaerobic incubation. All SMFCs (GO-SMFCs utilizing the soils incubated with GO produced electricity at a greater rate and in higher quantities than the SMFCs which did not contain GO. In fed-batch operations, the overall average electricity generation in GO-SMFCs containing 1.0 g•kg-1 of GO was 40 ± 19 mW•m-2, which was significantly higher than the value of 6.6 ± 8.9 mW•m-2 generated from GO-free SMFCs (p -2 of electricity after 27 days of operation. Collectively, this study demonstrates that GO added to soil can be microbially reduced in soil, and facilitates electron transfer to the anode in both SMFCs and PMFCs.

  14. Metabolic network modeling of microbial interactions in natural and engineered environmental systems

    Directory of Open Access Journals (Sweden)

    Octavio ePerez-Garcia

    2016-05-01

    Full Text Available We review approaches to characterize metabolic interactions within microbial communities using Stoichiometric Metabolic Network (SMN models for applications in environmental and industrial biotechnology. SMN models are computational tools used to evaluate the metabolic engineering potential of various organisms. They have successfully been applied to design and optimize the microbial production of antibiotics, alcohols and amino acids by single strains. To date however, such models have been rarely applied to analyze and control the metabolism of more complex microbial communities. This is largely attributed to the diversity of microbial community functions, metabolisms and interactions. Here, we firstly review different types of microbial interaction and describe their relevance for natural and engineered environmental processes. Next, we provide a general description of the essential methods of the SMN modeling workflow including the steps of network reconstruction, simulation through Flux Balance Analysis (FBA, experimental data gathering, and model calibration. Then we broadly describe and compare four approaches to model microbial interactions using metabolic networks, i.e. i lumped networks, ii compartment per guild networks, iii bi-level optimization simulations and iv dynamic-SMN methods. These approaches can be used to integrate and analyze diverse microbial physiology, ecology and molecular community data. All of them (except the lumped approach are suitable for incorporating species abundance data but so far they have been used only to model simple communities of two to eight different species. Interactions based on substrate exchange and competition can be directly modeled using the above approaches. However, interactions based on metabolic feedbacks, such as product inhibition and synthropy require extensions to current models, incorporating gene regulation and compounding accumulation mechanisms. SMN models of microbial

  15. The woodrat gut microbiota as an experimental system for understanding microbial metabolism of dietary toxins

    Directory of Open Access Journals (Sweden)

    Kevin D. Kohl

    2016-07-01

    Full Text Available The microbial communities inhabiting the alimentary tracts of mammals, particularly those of herbivores, are estimated to be one of the densest microbial reservoirs on Earth. The significance of these gut microbes in influencing the physiology, ecology and evolution of their hosts is only beginning to be realized. To understand the microbiome of herbivores with a focus on nutritional ecology, while evaluating the roles of host evolution and environment in sculpting microbial diversity, we have developed an experimental system consisting of the microbial communities of several species of herbivorous woodrats (genus Neotoma that naturally feed on a variety of dietary toxins. We designed this system to investigate the long-standing, but experimentally neglected hypothesis that ingestion of toxic diets by herbivores is facilitated by the gut microbiota. Like several other rodent species, the woodrat stomach has a sacculated, nongastric foregut portion. We have documented a dense and diverse community of microbes in the woodrat foregut, with several genera potentially capable of degrading dietary toxins and/or playing a role in stimulating hepatic detoxification enzymes of the host. The biodiversity of these gut microbes appears to be a function of host evolution, ecological experience and diet, such that dietary toxins increase microbial diversity in hosts with experience with these toxins while novel toxins depress microbial diversity. These microbial communities are critical to the ingestion of a toxic diet as reducing the microbial community with antibiotics impairs the host’s ability to feed on dietary toxins. Furthermore, the detoxification capacity of gut microbes can be transferred from Neotoma both intra and interspecifically to naïve animals that lack ecological and evolutionary history with these toxins. In addition to advancing our knowledge of complex host-microbes interactions, this system holds promise for identifying microbes that

  16. Microbial diversity and dynamics during methane production from municipal solid waste

    Energy Technology Data Exchange (ETDEWEB)

    Bareither, Christopher A., E-mail: christopher.bareither@colostate.edu [Civil and Environmental Engineering, Colorado State University, Ft. Collins, CO 80532 (United States); Geological Engineering, University of Wisconsin-Madison, Madison, WI 53706 (United States); Wolfe, Georgia L., E-mail: gwolfe@wisc.edu [Bacteriology, University of Wisconsin-Madison, Madison, WI 53706 (United States); McMahon, Katherine D., E-mail: tmcmahon@engr.wisc.edu [Bacteriology, Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, WI 53706 (United States); Benson, Craig H., E-mail: chbenson@wisc.edu [Civil and Environmental Engineering, Geological Engineering, University of Wisconsin-Madison, Madison, WI 53706 (United States)

    2013-10-15

    Highlights: ► Similar bacterial communities developed following different start-up operation. ► Total methanogens in leachate during the decelerated methane phase reflected overall methane yield. ► Created correlations between methanogens, methane yield, and available substrate. ► Predominant bacteria identified with syntrophic polysaccharide degraders. ► Hydrogenotrophic methanogens were dominant in the methane generation process. - Abstract: The objectives of this study were to characterize development of bacterial and archaeal populations during biodegradation of municipal solid waste (MSW) and to link specific methanogens to methane generation. Experiments were conducted in three 0.61-m-diameter by 0.90-m-tall laboratory reactors to simulate MSW bioreactor landfills. Pyrosequencing of 16S rRNA genes was used to characterize microbial communities in both leachate and solid waste. Microbial assemblages in effluent leachate were similar between reactors during peak methane generation. Specific groups within the Bacteroidetes and Thermatogae phyla were present in all samples and were particularly abundant during peak methane generation. Microbial communities were not similar in leachate and solid fractions assayed at the end of reactor operation; solid waste contained a more abundant bacterial community of cellulose-degrading organisms (e.g., Firmicutes). Specific methanogen populations were assessed using quantitative polymerase chain reaction. Methanomicrobiales, Methanosarcinaceae, and Methanobacteriales were the predominant methanogens in all reactors, with Methanomicrobiales consistently the most abundant. Methanogen growth phases coincided with accelerated methane production, and cumulative methane yield increased with increasing total methanogen abundance. The difference in methanogen populations and corresponding methane yield is attributed to different initial cellulose and hemicellulose contents of the MSW. Higher initial cellulose and

  17. Microbial diversity and dynamics during methane production from municipal solid waste

    International Nuclear Information System (INIS)

    Bareither, Christopher A.; Wolfe, Georgia L.; McMahon, Katherine D.; Benson, Craig H.

    2013-01-01

    Highlights: ► Similar bacterial communities developed following different start-up operation. ► Total methanogens in leachate during the decelerated methane phase reflected overall methane yield. ► Created correlations between methanogens, methane yield, and available substrate. ► Predominant bacteria identified with syntrophic polysaccharide degraders. ► Hydrogenotrophic methanogens were dominant in the methane generation process. - Abstract: The objectives of this study were to characterize development of bacterial and archaeal populations during biodegradation of municipal solid waste (MSW) and to link specific methanogens to methane generation. Experiments were conducted in three 0.61-m-diameter by 0.90-m-tall laboratory reactors to simulate MSW bioreactor landfills. Pyrosequencing of 16S rRNA genes was used to characterize microbial communities in both leachate and solid waste. Microbial assemblages in effluent leachate were similar between reactors during peak methane generation. Specific groups within the Bacteroidetes and Thermatogae phyla were present in all samples and were particularly abundant during peak methane generation. Microbial communities were not similar in leachate and solid fractions assayed at the end of reactor operation; solid waste contained a more abundant bacterial community of cellulose-degrading organisms (e.g., Firmicutes). Specific methanogen populations were assessed using quantitative polymerase chain reaction. Methanomicrobiales, Methanosarcinaceae, and Methanobacteriales were the predominant methanogens in all reactors, with Methanomicrobiales consistently the most abundant. Methanogen growth phases coincided with accelerated methane production, and cumulative methane yield increased with increasing total methanogen abundance. The difference in methanogen populations and corresponding methane yield is attributed to different initial cellulose and hemicellulose contents of the MSW. Higher initial cellulose and

  18. Microbial pretreatment of cotton stalks by Phanerochaete chrysosporium for bioethanol production

    Science.gov (United States)

    Shi, Jian

    Lignocellulosic biomass has been recognized as a widespread, potentially low cost renewable source of mixed sugars for fermentation to fuel ethanol. Pretreatment, as the first step towards conversion of lignocellulose to ethanol, remains one of the main barriers to technical and commercial success of the processing technology. Existing pretreatment methods have largely been developed on the basis of physiochemical technologies which are considered relatively expensive and usually involve adverse environmental impacts. In this study, an environmentally benign alternative, microbial pretreatment using Phanerochaete chrysosporium, was explored to degrade lignin in cotton stalks and facilitate their conversion into ethanol. Two submerged liquid pretreatment techniques (SmC), shallow stationary and agitated cultivation, at three inorganic salt concentrations (no salts, modified salts without Mn2+, modified salts with Mn2+) were compared by evaluating their pretreatment efficiencies. Shallow stationary cultivation with no salt was superior to other pretreatment conditions and gave 20.7% lignin degradation along with 76.3% solids recovery and 29.0% carbohydrate availability over a 14 day period. The influence of substrate moisture content (65%, 75% and 80% M.C. wet-basis), inorganic salt concentration (no salts, modified salts without Mn2+ , modified salts with Mn2+) and culture time (0-14 days) on pretreatment effectiveness in solid state (SSC) systems was also examined. It was shown that solid state cultivation at 75% M.C. without salts was the most preferable pretreatment resulting in 27.6% lignin degradation, 71.1% solids recovery and 41.6% carbohydrate availability over a period of 14 days. A study on hydrolysis and fermentation of cotton stalks treated microbially using the most promising SmC (shallow stationary, no salts) and SSC (75% moisture content, no salts) methods resulted in no increase in cellulose conversion with direct enzyme application (10.98% and 3

  19. The heterologous expression strategies of antimicrobial peptides in microbial systems.

    Science.gov (United States)

    Deng, Ting; Ge, Haoran; He, Huahua; Liu, Yao; Zhai, Chao; Feng, Liang; Yi, Li

    2017-12-01

    Antimicrobial peptides (AMPs) consist of molecules acting on the defense systems of numerous organisms toward tumor and multiple pathogens, such as bacteria, fungi, viruses, and parasites. Compared to traditional antibiotics, AMPs are more stable and have lower propensity for developing resistance through functioning in the innate immune system, thus having important applications in the fields of medicine, food and so on. However, despite of their high economic values, the low yield and the cumbersome extraction process in AMPs production are problems that limit their industrial application and scientific research. To conquer these obstacles, optimized heterologous expression technologies were developed that could provide effective ways to increase the yield of AMPs. In this review, the research progress on heterologous expression of AMPs using Escherichia coli, Bacillus subtilis, Pichia pastoris and Saccharomyces cerevisiae as host cells was mainly summarized, which might guide the expression strategies of AMPs in these cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Increased resiliency and activity of microbial mediated carbon cycling enzymes in diversified bioenergy cropping systems

    Science.gov (United States)

    Upton, R.; Bach, E.; Hofmockel, K. S.

    2017-12-01

    Microbes are mediators of soil carbon (C) and are influenced in membership and activity by nitrogen (N) fertilization and inter-annual abiotic factors. Microbial communities and their extracellular enzyme activities (EEA) are important parameters that influence ecosystem C cycling properties and are often included in microbial explicit C cycling models. In an effort to generate model relevant, empirical findings, we investigated how both microbial community structure and C degrading enzyme activity are influenced by inter-annual variability and N inputs in bioenergy crops. Our study was performed at the Comparison of Biofuel Systems field-site from 2011 to 2014, in three bioenergy cropping systems, continuous corn (CC) and two restored prairies, both fertilized (FP) and unfertilized (P). We hypothesized microbial community structure would diverge during the prairie restoration, leading to changes in C cycling enzymes over time. Using a sequencing approach (16S and ITS) we determined the bacterial and fungal community structure response to the cropping system, fertilization, and inter-annual variability. Additionally, we used EEA of β-glucosidase, cellobiohydrolase, and β-xylosidase to determine inter-annual and ecosystem impacts on microbial activity. Our results show cropping system was a main effect for microbial community structure, with corn diverging from both prairies to be less diverse. Inter-annual changes showed that a drought occurring in 2012 significantly impacted microbial community structure in both the P and CC, decreasing microbial richness. However, FP increased in microbial richness, suggesting the application of N increased resiliency to drought. Similarly, the only year in which C cycling enzymes were impacted by ecosystem was 2012, with FP supporting higher potential enzymatic activity then CC and P. The highest EEA across all ecosystems occurred in 2014, suggesting the continued root biomass and litter build-up in this no till system

  1. The system Around the Product

    DEFF Research Database (Denmark)

    Morelli, Nicola

          The design discipline has traditionally focused on products physical aspects, giving for granted that the context of services, infrastructures and technology will support the product life. A systemic perspective would revise such a focus, in order to project design competences over systemic...... aspects usually neglected by designers. This perspective shift is a challenge for designers, who have very efficient methods and tools to handle physical aspects of product design, but need to define an ?operative paradigm? to operate in a systemic context. An operative paradigm consists of a set of tools...... and methods to handle immaterial aspects such as time sequences, actors? role and logical links in a product service system (PSS). Tools and methods can be borrowed from other disciplinary contexts, their relevance, though, derives from their adaptation to this specific study area: designing in a systemic...

  2. Microbial Ecology and Evolution in the Acid Mine Drainage Model System.

    Science.gov (United States)

    Huang, Li-Nan; Kuang, Jia-Liang; Shu, Wen-Sheng

    2016-07-01

    Acid mine drainage (AMD) is a unique ecological niche for acid- and toxic-metals-adapted microorganisms. These low-complexity systems offer a special opportunity for the ecological and evolutionary analyses of natural microbial assemblages. The last decade has witnessed an unprecedented interest in the study of AMD communities using 16S rRNA high-throughput sequencing and community genomic and postgenomic methodologies, significantly advancing our understanding of microbial diversity, community function, and evolution in acidic environments. This review describes new data on AMD microbial ecology and evolution, especially dynamics of microbial diversity, community functions, and population genomes, and further identifies gaps in our current knowledge that future research, with integrated applications of meta-omics technologies, will fill. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Production of rhamnolipids by Pseudomonas aeruginosa is inhibited by H2S but resumes in a co-culture with P. stutzeri: applications for microbial enhanced oil recovery.

    Science.gov (United States)

    Zhao, Feng; Ma, Fang; Shi, Rongjiu; Zhang, Jie; Han, Siqin; Zhang, Ying

    2015-09-01

    Sulfate-reducing bacteria and H2S exist widely in oil production systems, and in situ production of rhamnolipids is promising for microbial enhanced oil recovery (MEOR). However, information of the effect of S(2-) on rhamnolipids production is scarce. Two facultative anaerobic rhamnolipids-producing bacterial strains, Pseudomonas aeruginosa SG and WJ-1, were used. Above 10 mg S(2-)/l, both cell growth and rhamnolipids production were inhibited. A large inoculum (9%, v/v) failed to completely relieve the inhibitory effect of 10 mg S(2-)/l. Below 30 mg S(2-)/l, both strains resumed rhamnolipid production through co-culturing with the denitrifying and sulphide-removing strain Pseudomonas stutzeri DQ1. H2S has a direct but reversible inhibitory effect on rhamnolipids production. Control of H2S in oilfields is indispensable to MEOR, and the co-culture method is effective in restoring rhamnolipid production in presence of S(2-).

  4. Energy landscapes shape microbial communities in hydrothermal systems on the Arctic Mid-Ocean Ridge.

    Science.gov (United States)

    Dahle, Håkon; Økland, Ingeborg; Thorseth, Ingunn H; Pederesen, Rolf B; Steen, Ida H

    2015-07-01

    Methods developed in geochemical modelling combined with recent advances in molecular microbial ecology provide new opportunities to explore how microbial communities are shaped by their chemical surroundings. Here, we present a framework for analyses of how chemical energy availability shape chemotrophic microbial communities in hydrothermal systems through an investigation of two geochemically different basalt-hosted hydrothermal systems on the Arctic Mid-Ocean Ridge: the Soria Moria Vent field (SMVF) and the Loki's Castle Vent Field (LCVF). Chemical energy landscapes were evaluated through modelling of the Gibbs energy from selected redox reactions under different mixing ratios between seawater and hydrothermal fluids. Our models indicate that the sediment-influenced LCVF has a much higher potential for both anaerobic and aerobic methane oxidation, as well as aerobic ammonium and hydrogen oxidation, than the SMVF. The modelled energy landscapes were used to develop microbial community composition models, which were compared with community compositions in environmental samples inside or on the exterior of hydrothermal chimneys, as assessed by pyrosequencing of partial 16S rRNA genes. We show that modelled microbial communities based solely on thermodynamic considerations can have a high predictive power and provide a framework for analyses of the link between energy availability and microbial community composition.

  5. Estimating Hydrogen Production Potential in Biorefineries Using Microbial Electrolysis Cell Technology

    Energy Technology Data Exchange (ETDEWEB)

    Borole, Abhijeet P [ORNL; Mielenz, Jonathan R [ORNL

    2011-01-01

    Microbial electrolysis cells (MECs) are devices that use a hybrid biocatalysis-electrolysis process for production of hydrogen from organic matter. Future biofuel and bioproducts industries are expected to generate significant volumes of waste streams containing easily degradable organic matter. The emerging MEC technology has potential to derive added- value from these waste streams via production of hydrogen. Biorefinery process streams, particularly the stillage or distillation bottoms contain underutilized sugars as well as fermentation and pretreatment byproducts. In a lignocellulosic biorefinery designed for producing 70 million gallons of ethanol per year, up to 7200 m3/hr of hydrogen can be generated. The hydrogen can either be used as an energy source or a chemical reagent for upgrading and other reactions. The energy content of the hydrogen generated is sufficient to meet 57% of the distillation energy needs. We also report on the potential for hydrogen production in existing corn mills and sugar-based biorefineries. Removal of the organics from stillage has potential to facilitate water recycle. Pretreatment and fermentation byproducts generated in lignocellulosic biorefinery processes can accumulate to highly inhibitory levels in the process streams, if water is recycled. The byproducts of concern including sugar- and lignin- degradation products such as furans and phenolics can also be converted to hydrogen in MECs. We evaluate hydrogen production from various inhibitory byproducts generated during pretreatment of various types of biomass. Finally, the research needs for development of the MEC technology and aspects particularly relevant to the biorefineries are discussed.

  6. Biogenic metallic nanoparticles as catalyst for bioelectricity production: A novel approach in microbial fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Saravanakumar, Kandasamy, E-mail: saravana732@gmail.com [School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai (China); State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai (China); Key Laboratory of Urban Agriculture (South), Ministry of Agriculture, Shanghai (China); MubarakAli, Davoodbasha [Microbial Genetic Engineering Laboratory, Division of Bioengineering, College of Life Science and Bioengineering, Incheon National University, Songdo 406772, Incheon (Korea, Republic of); Department of Microbiology, School of Lifesciences, Bharathidasan University, Tiruchirappalli 620024 (India); Kathiresan, Kandasamy [Centre of Advanced Study in Marine Biology, Faculty of Marine Sciences, Annamalai University, Parangipettai 608 502, Tamil Nadu (India); Thajuddin, Nooruddin [Department of Microbiology, School of Lifesciences, Bharathidasan University, Tiruchirappalli 620024 (India); Department of Botany and Microbiology, College of Science, King Saud University, Riyadh 11451 (Saudi Arabia); Alharbi, Naiyf S. [Department of Botany and Microbiology, College of Science, King Saud University, Riyadh 11451 (Saudi Arabia); Chen, Jie, E-mail: jiechen59@sjtu.edu.cn [School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai (China); State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai (China); Key Laboratory of Urban Agriculture (South), Ministry of Agriculture, Shanghai (China)

    2016-01-15

    Highlights: • Trichoderma sp., showed an abilities to synthesis of AgNPs and AuNPs with an excellent stability. • AuNPs significantly enhanced the bioelectricity production by MFC of anaerobic fermentation as catalyst. • Maximum bioelectricity production was optimized and obtained the voltage of 432.80 mA using RSM. - Abstract: The present work aimed to use the biogenic metallic nanoparticles as catalyst for bioelectricity production in microbial fuel cell (MFC) approach under anaerobic condition. Silver and gold nanoparticles (AuNPs) were synthesized using Trichoderma sp. Particle size and cystallinity were measured by X-ray diffraction revealed the crystalline structure with average size of 36.17 nm. Electron microscopic studies showed spherical shaped silver nanoparticles (AgNPs) and cubical shaped AuNPs with size ranges from 50 to 150 nm. The concentration of biogenic metallic nanoparticles as catalyst for enhanced bioelectricity generations and estimated by response surface methodology (RSM) and found at the greatest of 342.80 mA under optimized conditions are time interval, temperature, nanoparticles used as 63 h, 28 ± 2.0 °C, 22.54 mg l{sup −1} (AgNPs) and 25.62 mg l{sup −1} (AuNPs) in a batch reactor. AuNPs acted as an excellent catalyst to enhance the bioelectricity production. This novel technique could be used for eco-friendly, economically feasible and facile electricity production.

  7. Biogenic metallic nanoparticles as catalyst for bioelectricity production: A novel approach in microbial fuel cells

    International Nuclear Information System (INIS)

    Saravanakumar, Kandasamy; MubarakAli, Davoodbasha; Kathiresan, Kandasamy; Thajuddin, Nooruddin; Alharbi, Naiyf S.; Chen, Jie

    2016-01-01

    Highlights: • Trichoderma sp., showed an abilities to synthesis of AgNPs and AuNPs with an excellent stability. • AuNPs significantly enhanced the bioelectricity production by MFC of anaerobic fermentation as catalyst. • Maximum bioelectricity production was optimized and obtained the voltage of 432.80 mA using RSM. - Abstract: The present work aimed to use the biogenic metallic nanoparticles as catalyst for bioelectricity production in microbial fuel cell (MFC) approach under anaerobic condition. Silver and gold nanoparticles (AuNPs) were synthesized using Trichoderma sp. Particle size and cystallinity were measured by X-ray diffraction revealed the crystalline structure with average size of 36.17 nm. Electron microscopic studies showed spherical shaped silver nanoparticles (AgNPs) and cubical shaped AuNPs with size ranges from 50 to 150 nm. The concentration of biogenic metallic nanoparticles as catalyst for enhanced bioelectricity generations and estimated by response surface methodology (RSM) and found at the greatest of 342.80 mA under optimized conditions are time interval, temperature, nanoparticles used as 63 h, 28 ± 2.0 °C, 22.54 mg l"−"1 (AgNPs) and 25.62 mg l"−"1 (AuNPs) in a batch reactor. AuNPs acted as an excellent catalyst to enhance the bioelectricity production. This novel technique could be used for eco-friendly, economically feasible and facile electricity production.

  8. Evaluating the influence of process parameters on soluble microbial products formation using response surface methodology coupled with grey relational analysis.

    Science.gov (United States)

    Xu, Juan; Sheng, Guo-Ping; Luo, Hong-Wei; Fang, Fang; Li, Wen-Wei; Zeng, Raymond J; Tong, Zhong-Hua; Yu, Han-Qing

    2011-01-01

    Soluble microbial products (SMPs) present a major part of residual chemical oxygen demand (COD) in the effluents from biological wastewater treatment systems, and the SMP formation is greatly influenced by a variety of process parameters. In this study, response surface methodology (RSM) coupled with grey relational analysis (GRA) method was used to evaluate the effects of substrate concentration, temperature, NH(4)(+)-N concentration and aeration rate on the SMP production in batch activated sludge reactors. Carbohydrates were found to be the major component of SMP, and the influential priorities of these factors were: temperature>substrate concentration > aeration rate > NH(4)(+)-N concentration. On the basis of the RSM results, the interactive effects of these factors on the SMP formation were evaluated, and the optimal operating conditions for a minimum SMP production in such a batch activated sludge system also were identified. These results provide useful information about how to control the SMP formation of activated sludge and ensure the bioreactor high-quality effluent. Copyright © 2010 Elsevier Ltd. All rights reserved.

  9. Monitoring the Perturbation of Soil and Groundwater Microbial Communities Due to Pig Production Activities

    KAUST Repository

    Hong, Pei-Ying

    2013-02-08

    This study aimed to determine if biotic contaminants originating from pig production farms are disseminated into soil and groundwater microbial communities. A spatial and temporal sampling of soil and groundwater in proximity to pig production farms was conducted, and quantitative PCR (Q-PCR) was utilized to determine the abundances of tetracycline resistance genes (i.e., tetQ and tetZ) and integrase genes (i.e., intI1 and intI2). We observed that the abundances of tetZ, tetQ, intI1, and intI2 in the soils increased at least 6-fold after manure application, and their abundances remained elevated above the background for up to 16 months. Q-PCR further determined total abundances of up to 5.88 × 109 copies/ng DNA for tetZ, tetQ, intI1, and intI2 in some of the groundwater wells that were situated next to the manure lagoon and in the facility well used to supply water for one of the farms. We further utilized 16S rRNA-based pyrosequencing to assess the microbial communities, and our comparative analyses suggest that most of the soil samples collected before and after manure application did not change significantly, sharing a high Bray-Curtis similarity of 78.5%. In contrast, an increase in Bacteroidetes and sulfur-oxidizing bacterial populations was observed in the groundwaters collected from lagoon-associated groundwater wells. Genera associated with opportunistic human and animal pathogens, such as Acinetobacter, Arcobacter, Yersinia, and Coxiella, were detected in some of the manure-treated soils and affected groundwater wells. Feces-associated bacteria such as Streptococcus, Erysipelothrix, and Bacteroides were detected in the manure, soil, and groundwater ecosystems, suggesting a perturbation of the soil and groundwater environments by invader species from pig production activities.

  10. Characteristics and fates of soluble microbial products in ceramic membrane bioreactor at various sludge retention times.

    Science.gov (United States)

    Shin, Hang-Sik; Kang, Seok-Tae

    2003-01-01

    The formation and fate of soluble microbial products (SMP) in membrane bioreactor (MBR) was investigated at various sludge retention times (SRT) for 170 days. The SMP concentration was estimated by feeding glucose, which could be completely degraded, and by measuring the dissolved organic carbon (DOC) of the effluent from MBR. Under the conditions of SRT of 20 days, influent DOC of 112 mg/l and HRT of 6 h, the produced SMP was 4.7 mg DOC/l of which 57% was removed or retained by the membrane. DOC of MBR supernatant increased during 100 days and then gradually decreased. Specific UV absorbance showed that the accumulated compounds had a portion of larger, more aromatic, more hydrophobic and double-bond-rich organics, which originated from the decayed biomass. Molecular weight distributions of SMP in MBR supernatant showed that the acclimated microorganisms in a long SRT could decompose high molecular weight organics, it caused the shift of molecular weight distributions of SMP to a lower range. During the operation period, enumeration of active cells in the MBR showed that microbial inhibitions by accumulated SMP was not observed.

  11. Risk analysis of drinking water microbial contamination versus disinfection by-products (DBPs)

    International Nuclear Information System (INIS)

    Ashbolt, Nicholas John

    2004-01-01

    Managing the provision of safe drinking water has a renewed focus in light of the new World Health Organization (WHO) water safety plans. Risk analysis is a necessary component to assist in selecting priority hazards and identifying hazardous scenarios, be they qualitative to quantitative assessments. For any approach, acute diarrhoeal pathogens are often the higher risk issue for municipal water supplies, no matter how health burden is assessed. Furthermore, potential sequellae (myocarditis, diabetes, reactive arthritis and cancers) only further increase the potential health burden of pathogens; despite the enormous uncertainties in determining pathogen exposures and chemical dose-responses within respective microbial and chemical analyses. These interpretations are currently being improved by Bayesian and bootstrapping approaches to estimate parameters for stochastic assessments. A case example, covering the health benefits of ozonation for Cryptosporidium inactivation versus potential cancers from bromate exposures, illustrated the higher risks from a pathogen than one of the most likely disinfection by-products (DBPs). Such analyses help justify the industries long-held view of the benefits of multiple barriers to hazards and that microbial contamination of water supplies pose a clear public health risk when treatment is inadequate. Therefore, efforts to reduce potential health risks from DBP must not compromise pathogen control, despite socio-political issues

  12. An integrated metagenome and -proteome analysis of the microbial community residing in a biogas production plant.

    Science.gov (United States)

    Ortseifen, Vera; Stolze, Yvonne; Maus, Irena; Sczyrba, Alexander; Bremges, Andreas; Albaum, Stefan P; Jaenicke, Sebastian; Fracowiak, Jochen; Pühler, Alfred; Schlüter, Andreas

    2016-08-10

    To study the metaproteome of a biogas-producing microbial community, fermentation samples were taken from an agricultural biogas plant for microbial cell and protein extraction and corresponding metagenome analyses. Based on metagenome sequence data, taxonomic community profiling was performed to elucidate the composition of bacterial and archaeal sub-communities. The community's cytosolic metaproteome was represented in a 2D-PAGE approach. Metaproteome databases for protein identification were compiled based on the assembled metagenome sequence dataset for the biogas plant analyzed and non-corresponding biogas metagenomes. Protein identification results revealed that the corresponding biogas protein database facilitated the highest identification rate followed by other biogas-specific databases, whereas common public databases yielded insufficient identification rates. Proteins of the biogas microbiome identified as highly abundant were assigned to the pathways involved in methanogenesis, transport and carbon metabolism. Moreover, the integrated metagenome/-proteome approach enabled the examination of genetic-context information for genes encoding identified proteins by studying neighboring genes on the corresponding contig. Exemplarily, this approach led to the identification of a Methanoculleus sp. contig encoding 16 methanogenesis-related gene products, three of which were also detected as abundant proteins within the community's metaproteome. Thus, metagenome contigs provide additional information on the genetic environment of identified abundant proteins. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Microbial alkane production for jet fuel industry: motivation, state of the art and perspectives.

    Science.gov (United States)

    Jiménez-Díaz, Lorena; Caballero, Antonio; Pérez-Hernández, Natalia; Segura, Ana

    2017-01-01

    Bio-jet fuel has attracted a lot of interest in recent years and has become a focus for aircraft and engine manufacturers, oil companies, governments and researchers. Given the global concern about environmental issues and the instability of oil market, bio-jet fuel has been identified as a promising way to reduce the greenhouse gas emissions from the aviation industry, while also promoting energy security. Although a number of bio-jet fuel sources have been approved for manufacture, their commercialization and entry into the market is still a far way away. In this review, we provide an overview of the drivers for intensified research into bio-jet fuel technologies, the type of chemical compounds found in bio-jet fuel preparations and the current state of related pre-commercial technologies. The biosynthesis of hydrocarbons is one of the most promising approaches for bio-jet fuel production, and thus we provide a detailed analysis of recent advances in the microbial biosynthesis of hydrocarbons (with a focus on alkanes). Finally, we explore the latest developments and their implications for the future of research into bio-jet fuel technologies. © 2016 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  14. Rapid radiometric detection of microbial contamination using 14C-glucose and standard liquid scintillation counting system

    International Nuclear Information System (INIS)

    Joshi, S.H.; Kamble, S.B.; Pilkhwal, N.S.; Ramamoorthy, N.

    1998-01-01

    A simple and rapid method for detection of microbial contamination based on quantitation of 14 CO 2 released during metabolism of 14 C-Glucose by microorganisms is reported. Liquid scintillation counting system (LSCS) with a modified sample preparation method was utilised. The scintillator was impregnated on Whatman-1 paper on which 14 CO 2 evolved during metabolism could be absorbed. The important parameters of counting such as efficiency, position sensitivity and geometry as well as effect of NaOH quantity and of microbial load on detection period were studied. The efficiency of radioactivity assay was 18±2.8 %. Contamination of the order of 5-10 organism/ml of product could be detected in about 24 hours. (author)

  15. Microbial community response to chlorine conversion in a chloraminated drinking water distribution system.

    Science.gov (United States)

    Wang, Hong; Proctor, Caitlin R; Edwards, Marc A; Pryor, Marsha; Santo Domingo, Jorge W; Ryu, Hodon; Camper, Anne K; Olson, Andrew; Pruden, Amy

    2014-09-16

    Temporary conversion to chlorine (i.e., "chlorine burn") is a common approach to controlling nitrification in chloraminated drinking water distribution systems, yet its effectiveness and mode(s) of action are not fully understood. This study characterized occurrence of nitrifying populations before, during and after a chlorine burn at 46 sites in a chloraminated distribution system with varying pipe materials and levels of observed nitrification. Quantitative polymerase chain reaction analysis of gene markers present in nitrifying populations indicated higher frequency of detection of ammonia oxidizing bacteria (AOB) (72% of samples) relative to ammonia oxidizing archaea (AOA) (28% of samples). Nitrospira nitrite oxidizing bacteria (NOB) were detected at 45% of samples, while presence of Nitrobacter NOB could not be confirmed at any of the samples. During the chlorine burn, the numbers of AOA, AOB, and Nitrospira greatly reduced (i.e., 0.8-2.4 log). However, rapid and continued regrowth of AOB and Nitrospira were observed along with nitrite production in the bulk water within four months after the chlorine burn, and nitrification outbreaks appeared to worsen 6-12 months later, even after adopting a twice annual burn program. Although high throughput sequencing of 16S rRNA genes revealed a distinct community shift and higher diversity index during the chlorine burn, it steadily returned towards a condition more similar to pre-burn than burn stage. Significant factors associated with nitrifier and microbial community composition included water age and sampling location type, but not pipe material. Overall, these results indicate that there is limited long-term effect of chlorine burns on nitrifying populations and the broader microbial community.

  16. Bacterial production of short-chain organic acids and trehalose from levulinic acid: a potential cellulose-derived building block as a feedstock for microbial production.

    Science.gov (United States)

    Habe, Hiroshi; Sato, Shun; Morita, Tomotake; Fukuoka, Tokuma; Kirimura, Kohtaro; Kitamoto, Dai

    2015-02-01

    Levulinic acid (LA) is a platform chemical derived from cellulosic biomass, and the expansion of LA utilization as a feedstock is important for production of a wide variety of chemicals. To investigate the potential of LA as a substrate for microbial conversion to chemicals, we isolated and identified LA-utilizing bacteria. Among the six isolated strains, Pseudomonas sp. LA18T and Rhodococcus hoagie LA6W degraded up to 70 g/L LA in a high-cell-density system. The maximal accumulation of acetic acid by strain LA18T and propionic acid by strain LA6W was 13.6 g/L and 9.1 g/L, respectively, after a 4-day incubation. Another isolate, Burkholderia stabilis LA20W, produced trehalose extracellularly in the presence of 40 g/L LA to approximately 2 g/L. These abilities to produce useful compounds supported the potential of microbial LA conversion for future development and cellulosic biomass utilization. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. The SPOOKI post production system

    Science.gov (United States)

    Beauchemin, M.; Klasa, M.; Fortier, S.; Fortin, F.; Hardy, G.; Pelletier, L.; Edouard, S.; Archambault, B.; Yazidi, H.

    2010-09-01

    The Canadian Meteorological Centre (CMC) delivers a large number of numerical weather prediction products to the various weather offices and clients throughout Canada and abroad. The current post production system was built according to the needs and ideology of the 1980's and it is becoming obsolete with time. Its cumbersome architecture is difficult to maintain and requires a lot of human and computing resources. The "Weather Elements" section of CMC is aware of the problems associated with its maintenance in the long term and has therefore decided to review in depth the whole approach to the operational post production. The analysis of present and future needs have led to the development of an innovative concept in the operational production field inspired by the "Plug and Play" process. SPOOKI (Système de Production Orienté-Objet contennant une Kyrielle d'Informations - Object oriented production system containing a myriad of information) was created in its present form in 2007. It is based on a modular approach where each plug-in component is specialized, reusable and autonomous. These object oriented programming characteristics greatly simplify the maintenance of the system. Particular attention was also given to create a user-friendly system for novice users. An experimental version of SPOOKI is currently running in development mode and an operational one is planned to be implemented in the coming year. The poster presentation will describe SPOOKI, the future CMC operational post production system. Several examples of usage will be shown.

  18. Hydrogen Production by Geobacter Species and a Mixed Consortium in a Microbial Electrolysis Cell

    KAUST Repository

    Call, D. F.

    2009-10-09

    A hydrogen utilizing exoelectrogenic bacterium (Geobacter sulfurreducens) was compared to both a nonhydrogen oxidizer (Geobacter metallireducens) and a mixed consortium in order to compare the hydrogen production rates and hydrogen recoveries of pure and mixed cultures in microbial electrolysis cells (MECs). At an applied voltage of 0.7 V, both G. sulfurreducens and the mixed culture generated similar current densities (ca. 160 A/m3), resulting in hydrogen production rates of ca. 1.9 m3 H2/m 3/day, whereas G. metallireducens exhibited lower current densities and production rates of 110 ± 7 A/m3 and 1.3 ± 0.1 m3 H2/m3/day, respectively. Before methane was detected in the mixed-culture MEC, the mixed consortium achieved the highest overall energy recovery (relative to both electricity and substrate energy inputs) of 82% ± 8% compared to G. sulfurreducens (77% ± 2%) and G. metallireducens (78% ± 5%), due to the higher coulombic efficiency of the mixed consortium. At an applied voltage of 0.4 V, methane production increased in the mixed-culture MEC and, as a result, the hydrogen recovery decreased and the overall energy recovery dropped to 38% ± 16% compared to 80% ± 5% for G. sulfurreducens and 76% ± 0% for G. metallireducens. Internal hydrogen recycling was confirmed since the mixed culture generated a stable current density of 31 ± 0 A/m3 when fed hydrogen gas, whereas G. sulfurreducens exhibited a steady decrease in current production. Community analysis suggested that G. sulfurreducens was predominant in the mixed-culture MEC (72% of clones) despite its relative absence in the mixed-culture inoculum obtained from a microbial fuel cell reactor (2% of clones). These results demonstrate that Geobacter species are capable of obtaining similar hydrogen production rates and energy recoveries as mixed cultures in an MEC and that high coulombic efficiencies in mixed culture MECs can be attributed in part to the recycling of hydrogen into current. Copyright

  19. Hydrogen Production by Geobacter Species and a Mixed Consortium in a Microbial Electrolysis Cell▿

    Science.gov (United States)

    Call, Douglas F.; Wagner, Rachel C.; Logan, Bruce E.

    2009-01-01

    A hydrogen utilizing exoelectrogenic bacterium (Geobacter sulfurreducens) was compared to both a nonhydrogen oxidizer (Geobacter metallireducens) and a mixed consortium in order to compare the hydrogen production rates and hydrogen recoveries of pure and mixed cultures in microbial electrolysis cells (MECs). At an applied voltage of 0.7 V, both G. sulfurreducens and the mixed culture generated similar current densities (ca. 160 A/m3), resulting in hydrogen production rates of ca. 1.9 m3 H2/m3/day, whereas G. metallireducens exhibited lower current densities and production rates of 110 ± 7 A/m3 and 1.3 ± 0.1 m3 H2/m3/day, respectively. Before methane was detected in the mixed-culture MEC, the mixed consortium achieved the highest overall energy recovery (relative to both electricity and substrate energy inputs) of 82% ± 8% compared to G. sulfurreducens (77% ± 2%) and G. metallireducens (78% ± 5%), due to the higher coulombic efficiency of the mixed consortium. At an applied voltage of 0.4 V, methane production increased in the mixed-culture MEC and, as a result, the hydrogen recovery decreased and the overall energy recovery dropped to 38% ± 16% compared to 80% ± 5% for G. sulfurreducens and 76% ± 0% for G. metallireducens. Internal hydrogen recycling was confirmed since the mixed culture generated a stable current density of 31 ± 0 A/m3 when fed hydrogen gas, whereas G. sulfurreducens exhibited a steady decrease in current production. Community analysis suggested that G. sulfurreducens was predominant in the mixed-culture MEC (72% of clones) despite its relative absence in the mixed-culture inoculum obtained from a microbial fuel cell reactor (2% of clones). These results demonstrate that Geobacter species are capable of obtaining similar hydrogen production rates and energy recoveries as mixed cultures in an MEC and that high coulombic efficiencies in mixed culture MECs can be attributed in part to the recycling of hydrogen into current. PMID:19820150

  20. Methodological approaches for studying the microbial ecology of drinking water distribution systems.

    Science.gov (United States)

    Douterelo, Isabel; Boxall, Joby B; Deines, Peter; Sekar, Raju; Fish, Katherine E; Biggs, Catherine A

    2014-11-15

    The study of the microbial ecology of drinking water distribution systems (DWDS) has traditionally been based on culturing organisms from bulk water samples. The development and application of molecular methods has supplied new tools for examining the microbial diversity and activity of environmental samples, yielding new insights into the microbial community and its diversity within these engineered ecosystems. In this review, the currently available methods and emerging approaches for characterising microbial communities, including both planktonic and biofilm ways of life, are critically evaluated. The study of biofilms is considered particularly important as it plays a critical role in the processes and interactions occurring at the pipe wall and bulk water interface. The advantages, limitations and usefulness of methods that can be used to detect and assess microbial abundance, community composition and function are discussed in a DWDS context. This review will assist hydraulic engineers and microbial ecologists in choosing the most appropriate tools to assess drinking water microbiology and related aspects. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. Structure and dynamics of the microbial communities underlying the carboxylate platform for biofuel production

    Energy Technology Data Exchange (ETDEWEB)

    Hollister, Emily B.; Gentry, Terry J. [Texas A and M Univ., College Station, TX (United States). Dept. of Soil and Crop Sciences; Forrest, Andrea K.; Holtzapple, Mark T. [Texas A and M Univ., College Station, TX (United States). Dept. of Chemical Engineering; Wilkinson, Heather H.; Ebbole, Daniel J. [Texas A and M Univ., College Station, TX (United States). Dept. of Plant Pathology and Microbiology; Malfatti, Stephanie A.; Tringe, Susannah G. [DOE Joint Genome Institute, Walnut Creek, CA (United States)

    2010-09-15

    The carboxylate platform utilizes a mixed microbial community to convert lignocellulosic biomass into chemicals and fuels. While much of the platform is well understood, little is known about its microbiology. Mesophilic (40 C) and thermophilic (55 C) fermentations employing a sorghum feedstock and marine sediment inoculum were profiled using 16S rRNA tag-pyrosequencing over the course of a 30-day incubation. The contrasting fermentation temperatures converted similar amounts of biomass, but the mesophilic community was significantly more productive, and the two temperatures differed significantly with respect to propionic and butyric acid production. Pyrotag sequencing revealed the presence of dynamic communities that responded rapidly to temperature and changed substantially over time. Both temperatures were dominated by bacteria resembling Clostridia, but they shared few taxa in common. The species-rich mesophilic community harbored a variety of Bacteroidetes, Actinobacteria, and {gamma}-Proteobacteria, whereas the thermophilic community was composed mainly of Clostridia and Bacilli. Despite differences in composition and productivity, similar patterns of functional class dynamics were observed. Over time, organisms resembling known cellulose degraders decreased in abundance, while organisms resembling known xylose degraders increased. Improved understanding of the carboxylate platform's microbiology will help refine platform performance and contribute to our growing knowledge regarding biomass conversion and biofuel production processes. (orig.)

  2. High hydrogen production from glycerol or glucose by electrohydrogenesis using microbial electrolysis cells

    KAUST Repository

    Selembo, Priscilla A.

    2009-07-01

    The use of glycerol for hydrogen gas production was examined via electrohydrogenesis using microbial electrolysis cells (MECs). A hydrogen yield of 3.9 mol-H2/mol was obtained using glycerol, which is higher than that possible by fermentation, at relatively high rates of 2.0 ± 0.4 m3/m3 d (Eap = 0.9 V). Under the same conditions, hydrogen was produced from glucose at a yield of 7.2 mol-H2/mol and a rate of 1.9 ± 0.3 m3/m3 d. Glycerol was completely removed within 6 h, with 56% of the electrons in intermediates (primarily 1,3-propanediol), with the balance converted to current, intracellular storage products or biomass. Glucose was removed within 5 h, but intermediates (mainly propionate) accounted for only 19% of the electrons. Hydrogen was also produced using the glycerol byproduct of biodiesel fuel production at a rate of 0.41 ± 0.1 m3/m3 d. These results demonstrate that electrohydrogenesis is an effective method for producing hydrogen from either pure glycerol or glycerol byproducts of biodiesel fuel production. © 2009 International Association for Hydrogen Energy.

  3. Genetic and metabolic engineering for microbial production of poly-γ-glutamic acid.

    Science.gov (United States)

    Cao, Mingfeng; Feng, Jun; Sirisansaneeyakul, Sarote; Song, Cunjiang; Chisti, Yusuf

    2018-05-28

    Poly-γ-glutamic acid (γ-PGA) is a natural biopolymer of glutamic acid. The repeating units of γ-PGA may be derived exclusively from d-glutamic acid, or l-glutamic acid, or both. The monomer units are linked by amide bonds between the α-amino group and the γ-carboxylic acid group. γ-PGA is biodegradable, edible and water-soluble. It has numerous existing and emerging applications in processing of foods, medicines and cosmetics. This review focuses on microbial production of γ-PGA via genetically and metabolically engineered recombinant bacteria. Strategies for improving production of γ-PGA include modification of its biosynthesis pathway, enhancing the production of its precursor (glutamic acid), and preventing loss of the precursor to competing byproducts. These and other strategies are discussed. Heterologous synthesis of γ-PGA in industrial bacterial hosts that do not naturally produce γ-PGA is discussed. Emerging trends and the challenges affecting the production of γ-PGA are reviewed. Copyright © 2018. Published by Elsevier Inc.

  4. Glucose-based microbial production of the hormone melatonin in yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Germann, Susanne M; Baallal Jacobsen, Simo A; Schneider, Konstantin; Harrison, Scott J; Jensen, Niels B; Chen, Xiao; Stahlhut, Steen G; Borodina, Irina; Luo, Hao; Zhu, Jiangfeng; Maury, Jérôme; Forster, Jochen

    2016-05-01

    Melatonin is a natural mammalian hormone that plays an important role in regulating the circadian cycle in humans. It is a clinically effective drug exhibiting positive effects as a sleep aid and a powerful antioxidant used as a dietary supplement. Commercial melatonin production is predominantly performed by complex chemical synthesis. In this study, we demonstrate microbial production of melatonin and related compounds, such as serotonin and N-acetylserotonin. We generated Saccharomyces cerevisiae strains that comprise heterologous genes encoding one or more variants of an L-tryptophan hydroxylase, a 5-hydroxy-L-tryptophan decarboxylase, a serotonin acetyltransferase, an acetylserotonin O-methyltransferase, and means for providing the cofactor tetrahydrobiopterin via heterologous biosynthesis and recycling pathways. We thereby achieved de novo melatonin biosynthesis from glucose. We furthermore accomplished increased product titers by altering expression levels of selected pathway enzymes and boosting co-factor supply. The final yeast strain produced melatonin at a titer of 14.50 ± 0.57 mg L(-1) in a 76h fermentation using simulated fed-batch medium with glucose as sole carbon source. Our study lays the basis for further developing a yeast cell factory for biological production of melatonin. © 2015 The Authors. Biotechnology Journal published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. The presence of hydrogenotrophic methanogens in the inoculum improves methane gas production in microbial electrolysis cells.

    KAUST Repository

    Siegert, Michael; Li, Xiu-Fen; Yates, Matthew D; Logan, Bruce E

    2014-01-01

    High current densities in microbial electrolysis cells (MECs) result from the predominance of various Geobacter species on the anode, but it is not known if archaeal communities similarly converge to one specific genus. MECs were examined here on the basis of maximum methane production and current density relative to the inoculum community structure. We used anaerobic digester (AD) sludge dominated by acetoclastic Methanosaeta, and an anaerobic bog sediment where hydrogenotrophic methanogens were detected. Inoculation using solids to medium ratio of 25% (w/v) resulted in the highest methane production rates (0.27 mL mL(-1) cm(-2), gas volume normalized by liquid volume and cathode projected area) and highest peak current densities (0.5 mA cm(-2)) for the bog sample. Methane production was independent of solid to medium ratio when AD sludge was used as the inoculum. 16S rRNA gene community analysis using pyrosequencing and quantitative PCR confirmed the convergence of Archaea to Methanobacterium and Methanobrevibacter, and of Bacteria to Geobacter, despite their absence in AD sludge. Combined with other studies, these findings suggest that Archaea of the hydrogenotrophic genera Methanobacterium and Methanobrevibacter are the most important microorganisms for methane production in MECs and that their presence in the inoculum improves the performance.

  6. Experimental effect of ozone upon the microbial flora of commercially produced dairy fermented products.

    Science.gov (United States)

    Alexopoulos, A; Plessas, S; Kourkoutas, Y; Stefanis, C; Vavias, S; Voidarou, C; Mantzourani, I; Bezirtzoglou, E

    2017-04-04

    Ozone was used to control spoilage microorganisms during the manufacturing of dairy products. Ozone stream was applied onto the surface of freshly filled yoghurt cups just before storage for curd development in order to prevent cross contamination from spoilage airborne microorganisms. Accordingly, brine solution was bubbled with ozone for various periods of time and used for ripening of white (feta type) cheese. Both products were subjected to a continuous monitoring of microbial load and also tested for their sensorial properties. In ozonated yoghurt samples there was a reduction in mould counts of approximately 0.6Logcfu/g (25.1%) by the end of the monitoring period in relation to the control samples. In white cheese ripened with ozonated brine (1.3mg/L O 3 , NaCl 5%) it seems that ozone treatment during the two months of observation reduced some of the mould load but without offering any advantages over the use of traditional brine (NaCl 7%). However, some sensorial alterations were observed, probably due to the organic load in the brine which deactivates ozone in early stages of application. It is concluded that, if the factors of time and concentration of ozone are configured properly, ozonation could be a promising approach safeguarding the production of some dairy products. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Structure and dynamics of the microbial communities underlying the carboxylate platform for biofuel production

    Energy Technology Data Exchange (ETDEWEB)

    Hollister, Emily B; Gentry, Terry J [Texas A and M Univ., College Station, TX (United States). Dept. of Soil and Crop Sciences; Forrest, Andrea K; Holtzapple, Mark T [Texas A and M Univ., College Station, TX (United States). Dept. of Chemical Engineering; Wilkinson, Heather H; Ebbole, Daniel J [Texas A and M Univ., College Station, TX (United States). Dept. of Plant Pathology and Microbiology; Malfatti, Stephanie A; Tringe, Susannah G [DOE Joint Genome Institute, Walnut Creek, CA (United States)

    2010-09-15

    The carboxylate platform utilizes a mixed microbial community to convert lignocellulosic biomass into chemicals and fuels. While much of the platform is well understood, little is known about its microbiology. Mesophilic (40 C) and thermophilic (55 C) fermentations employing a sorghum feedstock and marine sediment inoculum were profiled using 16S rRNA tag-pyrosequencing over the course of a 30-day incubation. The contrasting fermentation temperatures converted similar amounts of biomass, but the mesophilic community was significantly more productive, and the two temperatures differed significantly with respect to propionic and butyric acid production. Pyrotag sequencing revealed the presence of dynamic communities that responded rapidly to temperature and changed substantially over time. Both temperatures were dominated by bacteria resembling Clostridia, but they shared few taxa in common. The species-rich mesophilic community harbored a variety of Bacteroidetes, Actinobacteria, and {gamma}-Proteobacteria, whereas the thermophilic community was composed mainly of Clostridia and Bacilli. Despite differences in composition and productivity, similar patterns of functional class dynamics were observed. Over time, organisms resembling known cellulose degraders decreased in abundance, while organisms resembling known xylose degraders increased. Improved understanding of the carboxylate platform's microbiology will help refine platform performance and contribute to our growing knowledge regarding biomass conversion and biofuel production processes. (orig.)

  8. The system around the product

    DEFF Research Database (Denmark)

    Morelli, Nicola

    2006-01-01

    The design discipline has traditionally focused on products’ physical aspects, giving for granted that the context of services, infrastructures and technology will support the product life. A systemic perspective would revise such a focus, in order to project design competences over systemic...... aspects usually neglected by designers. This perspective shift is a challenge for designers, who have very efficient methods and tools to handle physical aspects of product design, but need to define an ‘operative paradigm’ to operate in a systemic context. An operative paradigm consists of a set of tools...... and methods to handle immaterial aspects such as time sequences, actors’ role and logical links in a product service system (PSS). Tools and methods can be borrowed from other disciplinary contexts, their relevance, though, derives from their adaptation to this specific study area: designing in a systemic...

  9. Modeling the formation of soluble microbial products (SMP in drinking water biofiltration

    Directory of Open Access Journals (Sweden)

    Yu Xin

    2008-09-01

    Full Text Available Both a theoretical and an empirical model were developed for predicting the formation of soluble microbial products (SMP during drinking water biofiltration. Four pilot-scale biofilters with ceramsite as the medium were fed with different acetate loadings for the determination of SMP formation. Using numerically simulated and measured parameters, the theoretical model was developed according to the substrate and biomass balance. The results of this model matched the measured data better for higher SMP formation but did not fit well when SMP formation was lower. In order to better simulate the reality and overcome the difficulties of measuring the kinetic parameters, a simpler empirical model was also developed. In this model, SMP formation was expressed as a function of fed organic loadings and the depth of the medium, and a much better fit was obtained.

  10. Advances in metabolic engineering in the microbial production of fuels and chemicals from C1 gas.

    Science.gov (United States)

    Humphreys, Christopher M; Minton, Nigel P

    2018-04-01

    The future sustainable production of chemicals and fuels from non-petrochemical sources, while at the same time reducing greenhouse gas (GHG) emissions, represent two of society's greatest challenges. Microbial chassis able to grow on waste carbon monoxide (CO) and carbon dioxide (CO 2 ) can provide solutions to both. Ranging from the anaerobic acetogens, through the aerobic chemoautotrophs to the photoautotrophic cyanobacteria, they are able to convert C1 gases into a range of chemicals and fuels which may be enhanced and extended through appropriate metabolic engineering. The necessary improvements will be facilitated by the increasingly sophisticated gene tools that are beginning to emerge as part of the Synthetic Biology revolution. These tools, in combination with more accurate metabolic and genome scale models, will enable C1 chassis to deliver their full potential. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  11. Microbial production of natural gas from coal and organic-rich shale

    Science.gov (United States)

    Orem, William

    2013-01-01

    Natural gas is an important component of the energy mix in the United States, producing greater energy yield per unit weight and less pollution compared to coal and oil. Most of the world’s natural gas resource is thermogenic, produced in the geologic environment over time by high temperature and pressure within deposits of oil, coal, and shale. About 20 percent of the natural gas resource, however, is produced by microorganisms (microbes). Microbes potentially could be used to generate economic quantities of natural gas from otherwise unexploitable coal and shale deposits, from coal and shale from which natural gas has already been recovered, and from waste material such as coal slurry. Little is known, however, about the microbial production of natural gas from coal and shale.

  12. Dark fermentative hydrogen production by defined mixed microbial cultures immobilized on ligno-cellulosic waste materials

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Sanjay K.S. [Microbial Biotechnology and Genomics, Institute of Genomics and Integrative Biology (IGIB), CSIR, Delhi University Campus, Mall Road, Delhi 110007 (India); Department of Biotechnology, University of Pune, Pune 411007 (India); Purohit, Hemant J. [Environmental Genomics Unit, National Environmental Engineering Research Institute (NEERI), CSIR, Nehru Marg, Nagpur 440020 (India); Kalia, Vipin C. [Microbial Biotechnology and Genomics, Institute of Genomics and Integrative Biology (IGIB), CSIR, Delhi University Campus, Mall Road, Delhi 110007 (India)

    2010-10-15

    Mixed microbial cultures (MMCs) based on 11 isolates belonging to Bacillus spp. (Firmicutes), Bordetella avium, Enterobacter aerogenes and Proteus mirabilis (Proteobacteria) were employed to produce hydrogen (H{sub 2}) under dark fermentative conditions. Under daily fed culture conditions (hydraulic retention time of 2 days), MMC6 and MMC4, immobilized on ligno-cellulosic wastes - banana leaves and coconut coir evolved 300-330 mL H{sub 2}/day. Here, H{sub 2} constituted 58-62% of the total biogas evolved. It amounted to a H{sub 2} yield of 1.54-1.65 mol/mol glucose utilized over a period of 60 days of fermentation. The involvement of various Bacillus spp. -Bacillus sp., Bacillus cereus, Bacillus megaterium, Bacillus pumilus and Bacillus thuringiensis as components of the defined MMCs for H{sub 2} production has been reported here for the first time. (author)

  13. Isolation and characterization of the microbial community of a freshwater distribution system

    International Nuclear Information System (INIS)

    Balamurugan, P.; Subba Rao, T.

    2015-01-01

    This investigation provides generic information on culturable and non-culturable microbial community of a freshwater distribution system. Culture based and culture independent (16S rRNA gene sequencing) techniques were used to identify the resident microbial community of the system. Selective isolation of the fouling bacteria such as biofilm formers and corrosion causing bacteria was also attempted. Denaturing gradient gel electrophoresis (DGGE) was carried out and the bands were sequenced to obtain the diversity of the total bacterial types. Pseudomonas aeruginosa was predominantly observed in most of the samples. A variety of bacteria, related to groups such as Cyanobacteria, Proteobacteria, Actinobacteria, Bacteroidetes and Firmicutes were identified. The study highlights the relevance of the observed microbial diversity with respect to material deterioration in a freshwater distribution system, which can aid in designing effective control methods. (author)

  14. Methane production potential and microbial community structure for different forest soils

    Science.gov (United States)

    Matsumoto, Y.; Ueyama, M.; Kominami, Y.; Endo, R.; Tokumoto, H.; Hirano, T.; Takagi, K.; Takahashi, Y.; Iwata, H.; Harazono, Y.

    2017-12-01

    Forest soils are often considered as a methane (CH4) sink, but anaerobic microsites potentially decrease the sink at the ecosystem scale. In this study, we measured biological CH4 production potential of soils at various ecosystems, including upland forests, a lowland forest, and a bog, and analyzed microbial community structure using 16S ribosomal RNA (rRNA) genes. Three different types of soil samples (upland, bank of the stream, and center of the stream) were collected from Yamashiro forest meteorology research site (YMS) at Kyoto, Japan, on 11 May 2017. The soils were incubated at dark and anaerobic conditions under three different temperatures (37°C, 25°C, and 10°C) from 9 June 2017. The upland soils emitted CH4 with largest yields among the three soils at 37°C and 25°C, although no CH4 emission was observed at 10°C. For all temperature ranges, the emission started to increase with a 14- to 20-days lag after the start of the incubation. The lag indicates a slow transition to anaerobic conditions; as dissolved oxygen in water decreased, the number and/or activity of anaerobic bacteria like methanogens increased. The soils at the bank and center of the stream emitted CH4 with smaller yields than the upland soils in the three temperature ranges. The microbial community analyses indicate that methanogenic archaea presented at the three soils including the aerobic upland soil, but compositions of methanogenic archaea were different among the soils. In upland soils, hydrogenotrophic methanogens, such as Methanobacterium and Methanothermobacter, consisted almost all of the total methanogen detected. In the bank and center of the stream, soils contained approximately 10-25% of acetoclastic methanogens, such as Methanosarcina and Methanosaeta, among the total methanogen detected. Methanotrophs, a genus of Methanobacteriaceae, was appeared in the all types of soils. We will present results from same incubation and 16S rRNA analyses for other ecosystems, including

  15. Production of Microbial Transglutaminase on Media Made from Sugar Cane Molasses and Glycerol

    Directory of Open Access Journals (Sweden)

    Manuel Vázquez

    2009-01-01

    Full Text Available Transglutaminase is an enzyme that catalyses an acyl transfer reaction between γ-carboxamide groups of glutaminyl residues and lysine residues in proteins. Due to this property, this enzyme is used for enhancing textural properties of protein-rich food. The transglutaminase used as food additive is obtained by microorganisms, mainly by Streptoverticillium ladakanum. On the other hand, sugar cane molasses is a viscous liquid rich in noncrystallized carbohydrates (saccharose, glucose and fructose. In this work, the feasibility of using sugar cane molasses as a carbon source for the production of microbial transglutaminase by Streptoverticillium ladakanum NRRL 3191 has been studied. Carbon sources including sugar cane molasses (60 g of total sugars per L, glycerol (60 g/L and their mixture in a ratio of 1:1 (30 g/L of each were evaluated. Time course of microbial growth, transglutaminase activity and carbon source consumption were determined every 24 h during 120 h of fermentations at three agitation speeds (200, 300 or 400 rpm. The results showed that with the increase in agitation speed, the biomass concentration increased up to 8.39 g/L in the medium containing sugar cane molasses alone or the mixture of molasses and glycerol. The highest transglutaminase activity was obtained at 400 rpm in the medium containing a mixture of molasses and glycerol, reaching 0.460 U/mL, while in the medium containing sugar cane molasses alone, the activity was 0.240 U/mL, and using glycerol alone it was 0.250 U/mL. These results show that sugar cane molasses is a suitable medium for transglutaminase