WorldWideScience

Sample records for bioconversion

  1. Bioconversion of Cheese Waste (Whey)

    Energy Technology Data Exchange (ETDEWEB)

    Bohnert, G.W.

    1998-03-11

    The US dairy industry produces 67 billion pounds of cheese whey annually. A waste by-product of cheese production, whey consists of water, milk sugar (lactose), casein (protein), and salts amounting to about 7% total solids. Ultrafiltration is used to concentrate cheese whey into a protein-rich foodstuff; however, it too produces a waste stream, known as ''whey permeate,'' (rejected water, lactose, and salts from the membrane). Whey permeate contains about 4.5% lactose and requires treatment to reduce the high BOD (biological oxygen demand) before disposal. Ab Initio, a small business with strong chemistry and dairy processing background, desired help in developing methods for bioconversion of whey permeate lactose into lactic acid. Lactic acid is an organic acid primarily used as an acidulant in the food industry. More recently it has been used to produce polylactic acid, a biodegradable polymer and as a new method to treat meat carcasses to combat E. coli bacteria. Conversion of whey permeate to lactic acid is environmentally sound because it produces a valued product from an otherwise waste stream. FM&T has expertise in bioconversion processes and analytical techniques necessary to characterize biomass functions. The necessary engineering and analytical services for pilot biomass monitoring, process development, and purification of crude lactic acid were available at this facility.

  2. Bioconversion of Rebaudioside I from Rebaudioside A

    Directory of Open Access Journals (Sweden)

    Indra Prakash

    2014-10-01

    Full Text Available To supply the increasing demand of natural high potency sweeteners to reduce the calories in food and beverages, we have looked to steviol glycosides. In this work we report the bioconversion of rebaudioside A to rebaudioside I using a glucosyltransferase enzyme. This bioconversion reaction adds one sugar unit with a 1→3 linkage. We utilized 1D and 2D NMR spectroscopy (1H, 13C, COSY, HSQC-DEPT, HMBC, 1D TOCSY and NOESY and mass spectral data to fully characterize rebaudioside I.

  3. Bioconversion of rebaudioside I from rebaudioside A.

    Science.gov (United States)

    Prakash, Indra; Bunders, Cynthia; Devkota, Krishna P; Charan, Romila D; Ramirez, Catherine; Snyder, Tara M; Priedemann, Christopher; Markosyan, Avetik; Jarrin, Cyrille; Halle, Robert Ter

    2014-10-28

    To supply the increasing demand of natural high potency sweeteners to reduce the calories in food and beverages, we have looked to steviol glycosides. In this work we report the bioconversion of rebaudioside A to rebaudioside I using a glucosyltransferase enzyme. This bioconversion reaction adds one sugar unit with a 1→3 linkage. We utilized 1D and 2D NMR spectroscopy (1H, 13C, COSY, HSQC-DEPT, HMBC, 1D TOCSY and NOESY) and mass spectral data to fully characterize rebaudioside I.

  4. Bioconversion of Rebaudioside I from Rebaudioside A

    OpenAIRE

    Indra Prakash; Cynthia Bunders; Krishna P. Devkota; Romila D. Charan; Catherine Ramirez; Tara M. Snyder; Christopher Priedemann; Avetik Markosyan; Cyrille Jarrin; Robert Ter Halle

    2014-01-01

    To supply the increasing demand of natural high potency sweeteners to reduce the calories in food and beverages, we have looked to steviol glycosides. In this work we report the bioconversion of rebaudioside A to rebaudioside I using a glucosyltransferase enzyme. This bioconversion reaction adds one sugar unit with a 1→3 linkage. We utilized 1D and 2D NMR spectroscopy (1H, 13C, COSY, HSQC-DEPT, HMBC, 1D TOCSY and NOESY) and mass spectral data to fully characterize rebaudioside I.

  5. Separation and analysis of lignite bioconversion products

    Institute of Scientific and Technical Information of China (English)

    Yao Jinghua; Xiao Lei; Wang Liqiang

    2012-01-01

    The bioconversion of coal at ambient conditions is a promising technology for coal processing,although the mechanisms of coal degradation are still not understood fully.In this work,the bioconversion of lignite was studied using a fungus isolated from decaying wood.The lignite samples were oxidized with nitric acid under moderate conditions and then the oxidized samples were placed on a potato medium with isolated fungus for lignite bioconversion.Lignite,oxidized lignite and residual products after bioconversion of lignite were sequentially extracted with petroleum ether,CS2.methanol,acetone and tetrahydrofuran (THF),and then each extract was characterized by gas chromatography-mass spectrometry (GC/MS).The differences in composition and structure among the samples were inferred by comparing the differences between the extracts.The results show that aromatics with one or several benzene rings and their derivatives; and some long-chain alkanes containing oxygen decreased in the methanol-,acetone-,and THF-soluble fraction from residual lignite,whereas long chain or a few branched alkanes and small quantities of aromatic compounds increased in petroleum ether and CS2 soluble fractions.

  6. Fungal Bioconversion of Lignocellulosic Residues; Opportunities & Perspectives

    Directory of Open Access Journals (Sweden)

    Mehdi Dashtban, Heidi Schraft, Wensheng Qin

    2009-01-01

    Full Text Available The development of alternative energy technology is critically important because of the rising prices of crude oil, security issues regarding the oil supply, and environmental issues such as global warming and air pollution. Bioconversion of biomass has significant advantages over other alternative energy strategies because biomass is the most abundant and also the most renewable biomaterial on our planet. Bioconversion of lignocellulosic residues is initiated primarily by microorganisms such as fungi and bacteria which are capable of degrading lignocellulolytic materials. Fungi such as Trichoderma reesei and Aspergillus niger produce large amounts of extracellular cellulolytic enzymes, whereas bacterial and a few anaerobic fungal strains mostly produce cellulolytic enzymes in a complex called cellulosome, which is associated with the cell wall. In filamentous fungi, cellulolytic enzymes including endoglucanases, cellobiohydrolases (exoglucanases and β-glucosidases work efficiently on cellulolytic residues in a synergistic manner. In addition to cellulolytic/hemicellulolytic activities, higher fungi such as basidiomycetes (e.g. Phanerochaete chrysosporium have unique oxidative systems which together with ligninolytic enzymes are responsible for lignocellulose degradation. This review gives an overview of different fungal lignocellulolytic enzymatic systems including extracellular and cellulosome-associated in aerobic and anaerobic fungi, respectively. In addition, oxidative lignocellulose-degradation mechanisms of higher fungi are discussed. Moreover, this paper reviews the current status of the technology for bioconversion of biomass by fungi, with focus on mutagenesis, co-culturing and heterologous gene expression attempts to improve fungal lignocellulolytic activities to create robust fungal strains.

  7. Bioconversion of 2‑Ethylpyridine by Beauveria bassiana

    OpenAIRE

    Parshikov, Igor A; Khasaeva, Fatima M

    2015-01-01

    Investigated the bioconversion of 2-ethylpyridine by the fungus Beauveria bassiana ATCC 7159. In the result of researches was obtained the hydroxylated derivative of the initial substrate. The yield of the product was observed as 60 %.

  8. Applications for the pressurized anaerobic bioconversion; Paineistetun anaerobisen biokonversion sovellusmahdollisuudet

    Energy Technology Data Exchange (ETDEWEB)

    Kantero, M. [Preseco Oy, Espoo (Finland)

    2004-07-01

    The aim of the project is to develop more practical applications for the hygienization and gasification of biowaste based on the pressurized anaerobic bioconversion. Previous studies on the subject will be used as a basis for the project. The main research objectives are the hygienization effect of the pressurized anaerobic bioconversion, the maximizing of the biogas production and the methane ratio, and the development of the automation programs related to the previous objects. (orig.)

  9. Encapsulates for Food Bioconversions and Metabolite Production

    Science.gov (United States)

    Breguet, Véronique; Vojinovic, Vojislav; Marison, Ian W.

    The control of production costs in the food industry must be very strict as a result of the relatively low added value of food products. Since a wide variety of enzymes and/or cells are employed in the food industry for starch processing, cheese making, food preservation, lipid hydrolysis and other applications, immobilization of the cells and/or enzymes has been recognized as an attractive approach to improving food processes while minimizing costs. This is due to the fact that biocatalyst immobilization allows for easier separation/purification of the product and reutilization of the biocatalyst. The advantages of the use of immobilized systems are many, and they have a special relevance in the area of food technology, especially because industrial processes using immobilized biosystems are usually characterized by lower capital/energy costs and better logistics. The main applications of immobilization, related to the major processes of food bioconversions and metabolite production, will be described and discussed in this chapter.

  10. BIOCONVERSION OF WATER HYACINTH HYDROLYSATE INTO ETHANOL

    Directory of Open Access Journals (Sweden)

    Sunita Bandopadhyay Mukhopadhyay

    2010-04-01

    Full Text Available The fast growing aquatic weed water hyacinth, which is available almost year-round in the tropics and subtropics, was utilized as the chief source of cellulose for production of fuel ethanol via enzymatic hydrolysis and fermentation. Fungal cellulases produced on-site by utilizing acid-alkali pretreated water hyacinth as the substrate were used as the crude enzyme source for hydrolysis of identically pretreated biomass. Four different modes of enzymatic hydrolysis and fermentation were trialed in the present study for optimization of the yield of ethanol. Two common yeasts viz., Saccharomyces cerevisiae and Pachysolen tannophilus, were used for fermentation of hexose and pentose sugars in the hydrolysate. Significant enhancement of concentration (8.3 g/L and yield (0.21 g/g of ethanol was obtained through a prefermentation hydrolysis-simultaneous saccharification and fermentation (PH-SSF process, over the other three processes viz., separate hydrolysis and fermentation (SHF, simultaneous saccharification and fermentation (SSF, and single batch bioconversion (SBB by utilizing fungal culture broth with and without filtration as crude enzyme source.

  11. Direct Bioconversion of Oil Palm Empty Fruit Bunches for Bioethanol Production By Solid State Bioconversion

    Directory of Open Access Journals (Sweden)

    Nassereldeen Ahmed Kabbashi

    2010-09-01

    Full Text Available The bioethanol production was conducted by utilizing agriculture waste, palm oil empty fruit bunches (EFB with the aid of T. harzianum and yeast, Saccharomyces cerevisiae using solid state bioconversion method. The compatibility of various fungal strains was done as to develop the direct bioconversion process of compatible mixed culture. Analyzes such ethanol estimation, reducing sugar and glucosamine as growth indicator were conducted in order to select the best experimented run for optimization. The optimization of process conditions, by using central composite design (CCD was carried out. Optimization of process condition was done with varied level of moisture content, pH, inoculum size, concentration of co-substrate (wheat flour and mineral solutions. Statistical analysis showed that the optimum process condition for moisture content was 50% (v/w, pH of 4, inoculum size of 10% (v/v, concentration of wheat flour of 1% (v/v and mineral solutions 1%(v/v. In this study, the application levels of the methods of environmental management in regards to the maximum production were determined. The final optimization with the developed process conditions indicated that the maximum production was increased from 14.315 (v/v to 34.785(v/v.

  12. Bacterial biodegradation and bioconversion of industrial lignocellulosic streams.

    Science.gov (United States)

    Mathews, Stephanie L; Pawlak, Joel; Grunden, Amy M

    2015-04-01

    Lignocellulose is a term for plant materials that are composed of matrices of cellulose, hemicellulose, and lignin. Lignocellulose is a renewable feedstock for many industries. Lignocellulosic materials are used for the production of paper, fuels, and chemicals. Typically, industry focuses on transforming the polysaccharides present in lignocellulose into products resulting in the incomplete use of this resource. The materials that are not completely used make up the underutilized streams of materials that contain cellulose, hemicellulose, and lignin. These underutilized streams have potential for conversion into valuable products. Treatment of these lignocellulosic streams with bacteria, which specifically degrade lignocellulose through the action of enzymes, offers a low-energy and low-cost method for biodegradation and bioconversion. This review describes lignocellulosic streams and summarizes different aspects of biological treatments including the bacteria isolated from lignocellulose-containing environments and enzymes which may be used for bioconversion. The chemicals produced during bioconversion can be used for a variety of products including adhesives, plastics, resins, food additives, and petrochemical replacements.

  13. Bioconversion of biomass: a case study of ligno-cellulosics bioconversions in solid state fermentation

    Directory of Open Access Journals (Sweden)

    Ashok Pandey

    1998-08-01

    Full Text Available Lignocellulosic residues obtained from crops cultivation form useful sources to be used as substrate for bioconversion processes. Sugarcane bagasse, which is a complex substrate obtained from the processing of sugar cane, is an important biomass among such sources. Due to its abundant availability, it can serve as an ideal substrate for microbial processes for the production of value added products. This paper reviews recent developments on biological processes developed on production of various products in solid state fermentation using sugarcane bagasse as the substrate and describes production of protein enriched feed, enzymes, amino acid, organic acids and compounds of pharmaceutical importance, etc. through microbial means.Resíduos celulósicos obtidos a partir do cultivo de plantas podem ser utilizados como substratos nos processos de bioconversão. Bagaço de cana é um importante substrato e fonte de biomassa obtido a partir do processamento da cana de açucar. Em razão da sua produção em grandes volumes o mesmo pode ser utilizado como substrato ideal em processos microbianos para obtenção de produtos de elevado valor comercial. Esse trabalho de revisão apresenta os recentes desenvolvimentos em processos biológicos utilizando a técnica da fermentação no estado sólido na obtenção de enzimas, aminoácidos, ácidos orgânicos e componentes farmacêuticos de interesse industrial.

  14. Bioconversion technologies of crude glycerol to value added industrial products

    Directory of Open Access Journals (Sweden)

    Vijay Kumar Garlapati

    2016-03-01

    Full Text Available Crude glycerol that is produced as the by-product from biodiesel, has to be effectively utilized to contribute to the viability of biodiesel. Crude glycerol in large amounts can pose a threat to the environment. Therefore, there is a need to convert this crude glycerol into valued added products using biotechnological processes, which brings new revenue to biodiesel producers. Crude glycerol can serve as a feedstock for biopolymers, poly unsaturated fatty acids, ethanol, hydrogen and n-butanol production and as a raw material for different value added industrial products. Hence, in this review we have presented different bioconversion technologies of glycerol to value added industrial products.

  15. Bioconversion of isopropanol by a solvent tolerant Sphingobacterium mizutae strain.

    Science.gov (United States)

    Mohammad, Balsam T; Wright, Phillip C; Bustard, Mark T

    2006-12-01

    The bioconversion of high concentration isopropanol (2-propanol, IPA) was investigated by a solvent tolerant strain of bacteria, which was identified as Sphingobacterium mizutae ST2 by partial 16S rDNA gene sequencing. This strain of bacteria exhibited the ability to utilise high concentration isopropanol as the sole carbon source, with mineralization occurring via an acetone intermediate into central metabolism. The biodegradative performance of this strain for IPA was examined over a 2-38 g l(-1) concentration range, using specific growth rate (mu) and conversion rate analysis. Maximum specific growth rates (mu(max)) of 0.0045 h(-1 )were routinely obtainable on IPA. In addition, the highest specific IPA degradation rate was obtained at a concentration of 7.5 g l(-1) with a corresponding value of 0.045 g IPA g cells(-1) h(-1). While the highest acetone yield reached its maximum value of 0.940 g acetone g IPA(-1) at 7.5 g IPA l(-1). This is the first report on bioconversion of isopropanol at such high concentration by this solvent tolerant strain of S. mizutae and may allow its application in novel biocatalytic processes for effective biological conversion in two-phase solvent systems.

  16. Evaluation of fungal potentiality for bioconversion of domestic wastewater sludge

    Institute of Scientific and Technical Information of China (English)

    Md. Zahangir Alam; A. Fakhru'l-Razi; Abul H. Molla

    2004-01-01

    This study was undertaken to screen the filamentous fungi isolated from its relevant habitats(wastewater, sewage sludge and sludge cake) for the bioconversion of domestic wastewater sludge. A total of 35 fungal strains were tested against wastewater sludge (total suspended solids, TSS 1%-5% w/w) to evaluate its potentiality for enhancing the biodegradability and dewaterability using liquid state bioconversion(LSB) process. The strains were divided into five groups i. e. Penicillium, Aspergillus, Trichoderma, Basidiomycete and Miscellaneous, respectively. The strains WWZP1003, SCahmA103, SCahmT105 and PC-9 among their respective groups of Penicillium,Aspergillus, Trichoderma and Basidiomycete played potential roles in terms of separation (formation of pellets/flocs/filaments ),biodegradation(removal of COD) and filtration(filterability) of treated domestic wastewater sludge. The Miscellaneous group was not considered due to its unsatisfactory results as compared to the other groups. The pH value was also influenced by the microbial treatment during fermentation process. The filterability of treated sludge was improved by fungal treatment, and lowest filtration time was recorded for the strain WWZP1003 and SCahmA103 of Penicillium and Aspergillus groups respectively compared with other strains.

  17. Copper sulfate improves pullulan production by bioconversion using whole cells of Aureobasidium pullulans as the catalyst.

    Science.gov (United States)

    Wang, Dahui; Ju, Xiaomin; Zhang, Gaochuan; Wang, Donghua; Wei, Gongyuan

    2016-10-01

    The effects of mineral salts on pullulan production by bioconversion using whole cells of Aureobasidium pullulans CCTCC M 2012259 as the catalyst were investigated. Copper sulfate (CuSO4) improved pullulan production by 36.2% and 42.3% when added at the optimum concentration of 0.2mg/L to the bioconversion broth or seed medium, respectively, as compared with controls without CuSO4 addition. Pullulan production was further enhanced when CuSO4 was added to both seed medium and bioconversion broth simultaneously. In order to probe the mechanism of CuSO4 improvement, cell viability, membrane integrity, intracellular adenosine triphosphate (ATP) levels and the activities of key enzymes involved in pullulan biosynthesis were determined. As a result, CuSO4 increased the activities of key biosynthetic enzymes, maintained intracellular ATP at a higher level, and accelerated the rate of pullulan secretion, all of which contributed to improved pullulan production by bioconversion.

  18. Advancing lignocellulose bioconversion through direct assessment of enzyme action on insoluble substrates

    DEFF Research Database (Denmark)

    Goacher, Robyn E.; Selig, Michael J.; Master, Emma R.

    2014-01-01

    Microbial utilization of lignocellulose from plant cell walls is integral to carbon cycling on Earth. Correspondingly, secreted enzymes that initiate lignocellulose depolymerization serve a crucial step in the bioconversion of lignocellulosic biomass to fuels and chemicals. Genome and metagenome...

  19. Bioconversion of chicken wastes to value-added products

    Energy Technology Data Exchange (ETDEWEB)

    Barik, S.; Forgacs, T.; Isbister, J. (ARCTECH, Inc., Alexandria, VA (United States))

    1991-01-01

    Increasing quantities of chicken waste concerns the poultry industry because of escalating disposal costs and the potential for environmental pollution. Biological conversion of these wastes to valuable products such as methane and/or chemical feed-stocks appears to be feasible. Biomethanation of chicken waste by a sewage sludge microbial consortium produced as much as 69 mol% methane in the gas phase. Acetic and propionic acids were the major acids produced during the bioconversion. Addition of chelating agents and other micro-nutrients enhanced methane production and shifted the ratios of intermediates accumulated. Preliminary data indicate that more than 60% of the chicken waste carbon was converted and that the nitrogen-rich residue may have potential as a soil additive. (author).

  20. Pseudomonas: a promising biocatalyst for the bioconversion of terpenes.

    Science.gov (United States)

    Molina, Gustavo; Pimentel, Mariana R; Pastore, Gláucia M

    2013-03-01

    The Pseudomonas genus is one of the most diverse and ecologically significant groups of known bacteria, and it includes species that have been isolated worldwide in all types of environments. The bacteria from this genus are characterized by an elevated metabolic versatility, which is due to the presence of a complex enzymatic system. Investigations since the early 1960s have demonstrated their potential as biocatalysts for the production of industrially relevant and value-added flavor compounds from terpenes. Although terpenes are often removed from essential oils as undesirable components, its synthetic oxy-functionalized derivatives have broad applications in flavors/fragrances and pharmaceutical industries. Hence, biotransformation appears to be an effective tool for the structural modification of terpene hydrocarbons and terpenoids to synthesize novel and high-valued compounds. This review highlights the potential of Pseudomonas spp. as biocatalysts for the bioconversion of terpenes and summarizes the presently known bioflavors that are obtained from these processes.

  1. Bioconversion of petroleum hydrocarbons in soil using apple filter cake

    Science.gov (United States)

    Medaura, M. Cecilia; Ércoli, Eduardo C.

    2008-01-01

    The aim of this study was to investigate the feasibility of using apple filter cake, a fruit-processing waste to enhance the bioremediation of petroleum contaminated soil. A rotating barrel system was used to study the bioconversion of the xenobiotic compound by natural occurring microbial population. The soil had been accidentally polluted with a total petroleum hydrocarbon concentration of 41,000 ppm. Although this global value was maintained during the process, microbial intervention was evidenced through transformation of the petroleum fractions. Thus, fractions that represent a risk for the environment (GRO, Gasoline Range Organics i.e., C6 to C10–12; DRO, Diesel Range Organics i.e., C8–12 to C24–26 and RRO, Residual Range Organics i.e., C25 to C35) were significantly reduced, from 2.95% to 1.39%. On the contrary, heavier weight fraction from C35 plus other organics increased in value from 1.15% to 3.00%. The noticeable diminution of low molecular weight hydrocarbons content and hence environmental risk by the process plus the improvement of the physical characteristics of the soil, are promising results with regard to future application at large scale. PMID:24031241

  2. [Bioconversion of sewage sludge to biopesticide by Bacillus thuringiensis].

    Science.gov (United States)

    Chang, Ming; Zhou, Shun-gui; Lu, Na; Ni, Jin-ren

    2006-07-01

    Feasibility of bioconversion of sewage sludge to biopesticide by Bacillus thuringiensis was studied using sewage sludge as a raw material. The fermentation was also compared with conventional medium. Results showed that without any pretreatment, the nutrients contained in sewage sludge were almost sufficient for Bacillus thuringiensis growth, even with a rapid multiplicational rate. Higher viable cells and viable spores values were obtained earlier at 24 h, with 9.48 x 10(8) CFU x mL(-1) and 8.51 x 10(8) CFU x mL(-1) respectively, which was 12 hours earlier and nearly 20 percent higher than conventional medium. SEM of 36 h samples gave a clear phenomenon that the metabolizability in sludge was much faster with spores and crystals spreading around. The crystals in sludge seemed rather bigger and more regular. Also a better crystal protein yield of 2.80 mg x mL(-1) was observed in sludge medium compared to conventional medium at the end of fermentation. Sludge fermentation for Bacillus thuringiensis reduces the producing cost, and gives better fermentation capabilities. It's expected to be a new method for sludge disposal.

  3. Bioconversion of natural gas to liquid fuel: Opportunities and challenges

    Energy Technology Data Exchange (ETDEWEB)

    Fei, Q; Guarnieri, MT; Tao, L; Laurens, LML; Dowe, N; Pienkos, PT

    2014-05-01

    Natural gas is a mixture of low molecular weight hydrocarbon gases that can be generated from either fossil or anthropogenic resources. Although natural gas is used as a transportation fuel, constraints in storage, relatively low energy content (MJ/L), and delivery have limited widespread adoption. Advanced utilization of natural gas has been explored for biofuel production by microorganisms. In recent years, the aerobic bioconversion of natural gas (or primarily the methane content of natural gas) into liquid fuels (Bio-GTL) by biocatalysts (methanotrophs) has gained increasing attention as a promising alternative for drop-in biofuel production. Methanotrophic bacteria are capable of converting methane into microbial lipids, which can in turn be converted into renewable diesel via a hydrotreating process. In this paper, biodiversity, catalytic properties and key enzymes and pathways of these microbes are summarized. Bioprocess technologies are discussed based upon existing literature, including cultivation conditions, fermentation modes, bioreactor design, and lipid extraction and upgrading. This review also outlines the potential of Bio-GTL using methane as an alternative carbon source as well as the major challenges and future research needs of microbial lipid accumulation derived from methane, key performance index, and techno-economic analysis. An analysis of raw material costs suggests that methane-derived diesel fuel has the potential to be competitive with petroleum-derived diesel. (C) 2014 The Authors. Published by Elsevier Inc.

  4. Bioconversion of Natural Gas to Liquid Fuel. Opportunities and Challenges

    Energy Technology Data Exchange (ETDEWEB)

    Fei, Qiang [National Renewable Energy Lab. (NREL), Golden, CO (United States); Guarnieri, Michael T. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Tao, Ling [National Renewable Energy Lab. (NREL), Golden, CO (United States); Laurens, Lieve M. L. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Dowe, Nancy [National Renewable Energy Lab. (NREL), Golden, CO (United States); Pienkos, Philip T. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2014-05-01

    Natural gas is a mixture of low molecular weight hydrocarbon gases that can be generated from either fossil or anthropogenic resources. Although natural gas is used as a transportation fuel, constraints in storage, relatively low energy content (MJ/L), and delivery have limited widespread adoption. Advanced utilization of natural gas has been explored for biofuel production by microorganisms. In recent years, the aerobic bioconversion of natural gas (or primarily the methane content of natural gas) into liquid fuels (Bio-GTL) by biocatalysts (methanotrophs) has gained increasing attention as a promising alternative for drop-in biofuel production. Moreover, methanotrophic bacteria are capable of converting methane into microbial lipids, which can in turn be converted into renewable diesel via a hydrotreating process. In this paper, biodiversity, catalytic properties and key enzymes and pathways of these microbes are summarized. Bioprocess technologies are discussed based upon existing literature, including cultivation conditions, fermentation modes, bioreactor design, and lipid extraction and upgrading. Our review also outlines the potential of Bio-GTL using methane as an alternative carbon source as well as the major challenges and future research needs of microbial lipid accumulation derived from methane, key performance index, and techno-economic analysis. An analysis of raw material costs suggests that methane-derived diesel fuel has the potential to be competitive with petroleum-derived diesel.

  5. [Novel bioconversion systems using a yeast molecular display system].

    Science.gov (United States)

    Shibasaki, Seiji

    2010-11-01

    The budding yeast Saccharomyces cerevisiae has been used for the process of fermentation as well as for studies in biochemistry and molecular biology as a eukaryotic model cell or tool for the analysis of gene functions. Thus, yeast is essential in industries and researches. Yeast cells have a cell wall, which is one characteristic that helps distinguish yeast cells from other eukaryotic cells such as mammalian cells. We have developed a molecular display system using the protein of the yeast cell wall as an anchor for foreign proteins. Yeast cells have been designed for use in sensing and metal adsorption, and have been used in vaccines and for screening novel proteins. Currently, yeast is used not only as a tool for analyzing gene or protein function but also in molecular display technology. The phage display system, which is at the forefront of molecular display technologies, is a powerful tool for screening ligands bound to a target molecule and for analyzing protein-protein interactions; however, in some cases, eukaryotic proteins are not easily expressed by this system. On the other hand, yeast cells have the ability to express eukaryotic proteins and proliferate; thus, these cells display various proteins. Yeast cells are more appropriate for white biotechnology. In this review, displays of enzymes that are important in bioconversion, such as lipases and β-glucosidases, are going to be introduced.

  6. Bioconversion of piceid to resveratrol by selected probiotic cell extracts.

    Science.gov (United States)

    Basholli-Salihu, Mimoza; Schuster, Roswitha; Mulla, Dafina; Praznik, Werner; Viernstein, Helmut; Mueller, Monika

    2016-12-01

    Resveratrol exerts several pharmacological activities, including anti-cancer, anti-inflammatory, cardioprotective, or antioxidant effects. However, due to its occurrence in plants more in glycosidic form as piceid, the bioavailability and bioactivity are limited. The enzymatic potential of probiotics for the transformation of piceid to resveratrol was elucidated. Cell extract from Bifidobacteria (B.) infantis, B. bifidum, Lactobacillus (L.) casei, L. plantarum, and L. acidophilus was evaluated for their effect in this bioconversion using high-performance liquid chromatography (HPLC) as analytical tool. Cell extract of B. infantis showed the highest effect on the deglycosylation of piceid to resveratrol, already after 30 min. Cell extracts of all other tested strains showed a significant biotransformation with no further metabolization of resveratrol. The conversion of piceid to resveratrol is of importance to increase bioavailability and bioactivity as shown for anti-inflammation in this study. Cell extracts from probiotics, especially from B. infantis, may be added to piceid containing products, for achieving higher biological effects caused by the bioactivity of resveratrol or by health promoting of the probiotics. These findings open a new perspective of novel combination of cell extracts from probiotics and piceid, in health-promoting pharmaceutical and food products.

  7. Bioconversion of natural gas to liquid fuel: opportunities and challenges.

    Science.gov (United States)

    Fei, Qiang; Guarnieri, Michael T; Tao, Ling; Laurens, Lieve M L; Dowe, Nancy; Pienkos, Philip T

    2014-01-01

    Natural gas is a mixture of low molecular weight hydrocarbon gases that can be generated from either fossil or anthropogenic resources. Although natural gas is used as a transportation fuel, constraints in storage, relatively low energy content (MJ/L), and delivery have limited widespread adoption. Advanced utilization of natural gas has been explored for biofuel production by microorganisms. In recent years, the aerobic bioconversion of natural gas (or primarily the methane content of natural gas) into liquid fuels (Bio-GTL) by biocatalysts (methanotrophs) has gained increasing attention as a promising alternative for drop-in biofuel production. Methanotrophic bacteria are capable of converting methane into microbial lipids, which can in turn be converted into renewable diesel via a hydrotreating process. In this paper, biodiversity, catalytic properties and key enzymes and pathways of these microbes are summarized. Bioprocess technologies are discussed based upon existing literature, including cultivation conditions, fermentation modes, bioreactor design, and lipid extraction and upgrading. This review also outlines the potential of Bio-GTL using methane as an alternative carbon source as well as the major challenges and future research needs of microbial lipid accumulation derived from methane, key performance index, and techno-economic analysis. An analysis of raw material costs suggests that methane-derived diesel fuel has the potential to be competitive with petroleum-derived diesel.

  8. Bioconversion of rice straw into a soil-like substrate

    Science.gov (United States)

    Yu, Chengying; Liu, Hong; Xing, Yidong; Manukovsky, N. S.; Kovalev, V. S.; Gurevich, Yu. L.

    To increase the closure of bioregenerative life support systems (BLSS), the bioconversion of rice straw into a soil-like substrate (SLS) by mushrooms and worms has been studied. The results showed that rice straw could be treated better by aerobic fermentation and succeeding growth of mushrooms Pleurotus ostreatus. In this process the total content of lignocellulose in the straw was removed by 37.74%. Furthermore, 46.68 g (fresh weight) of mushrooms could be produced from 100.0 g (dry weight) of rice straw. During the conversion of rice straw into a starting SLS by mushrooms and worms, the matter loss was 77.31%. The lettuce has been planted in the SLS and the yield when lettuce was cultivated on the SLS (8.77gm-2day-1) was comparable to the yield obtained on the nutrient solution. In addition, the silicon in the SLS ash can reach upto 32% and the circulation of it is expected during the growth of rice.

  9. Advanced modelling, monitoring, and process control of bioconversion systems

    Science.gov (United States)

    Schmitt, Elliott C.

    Production of fuels and chemicals from lignocellulosic biomass is an increasingly important area of research and industrialization throughout the world. In order to be competitive with fossil-based fuels and chemicals, maintaining cost-effectiveness is critical. Advanced process control (APC) and optimization methods could significantly reduce operating costs in the biorefining industry. Two reasons APC has previously proven challenging to implement for bioprocesses include: lack of suitable online sensor technology of key system components, and strongly nonlinear first principal models required to predict bioconversion behavior. To overcome these challenges batch fermentations with the acetogen Moorella thermoacetica were monitored with Raman spectroscopy for the conversion of real lignocellulosic hydrolysates and a kinetic model for the conversion of synthetic sugars was developed. Raman spectroscopy was shown to be effective in monitoring the fermentation of sugarcane bagasse and sugarcane straw hydrolysate, where univariate models predicted acetate concentrations with a root mean square error of prediction (RMSEP) of 1.9 and 1.0 g L-1 for bagasse and straw, respectively. Multivariate partial least squares (PLS) models were employed to predict acetate, xylose, glucose, and total sugar concentrations for both hydrolysate fermentations. The PLS models were more robust than univariate models, and yielded a percent error of approximately 5% for both sugarcane bagasse and sugarcane straw. In addition, a screening technique was discussed for improving Raman spectra of hydrolysate samples prior to collecting fermentation data. Furthermore, a mechanistic model was developed to predict batch fermentation of synthetic glucose, xylose, and a mixture of the two sugars to acetate. The models accurately described the bioconversion process with an RMSEP of approximately 1 g L-1 for each model and provided insights into how kinetic parameters changed during dual substrate

  10. Bioconversion of leukotriene C4 by the bullfrog heart.

    Science.gov (United States)

    Herman, R P; Heller, R S; Canavan, C M; Herman, C A

    1988-01-01

    Isolated perfused bullfrog hearts were administered randomized doses of LTC4, LTD4 or LTE4. The cardiac parameters of heart rate, developed tension and its first derivative (dT/dt) were recorded. LTC4 was the most potent of the leukotrienes tested in eliciting positive inotropic effects. LTD4 and LTE4 were equally effective but about one order of magnitude less potent than LTC4. None of the LTs showed any chronotropic effects in this preparation. LTC4 was significantly more potent in the presence of L-serine borate, an inhibitor of gamma-glutamyl transpeptidase, than in its absence, raising the possibility of significant bioconversion of LTC4 by the bullfrog heart. 3H-LTC4 metabolism experiments were carried out using whole perfused hearts or minced bullfrog heart tissue. During the six minute course of collection, the isolated perfused heart converted significant amounts of LTC4 to LTD4 and to a lesser degree LTE4. This conversion was attenuated in the presence of L-serine borate. Both minced atrial and ventricular tissue converted 3H-LTC4 to radioactive metabolites which co-migrated with authentic LTD4 and LTE4 standards. In both tissues, the major product was LTD4, with smaller amounts of LTE4 produced. The atrium converted significantly more LTC4 to its metabolites than did the ventricle. The metabolism of LTC4 to LTD4 by both tissues was virtually abolished in the presence of serine borate. It is interesting that LTC4 metabolism pattern and rate is comparable in mammals and frogs in spite of the fact that the inotropic effects of leukotrienes are opposite in the two taxa and, in frogs, metabolism results in a less potent agent.

  11. Xanthobacter sp. C20 contains a novel bioconversion pathway for limonene

    NARCIS (Netherlands)

    Werf, M.J. van der; Keijzer, P.M.; Schaft, P.H. van der

    2000-01-01

    Xanthobacter sp. C20 was isolated from sediment of the river Rhine using cyclohexane as sole source of carbon and energy. Xanthobacter sp. C20 converted both enantiomers of limonene quantitatively into limonene-8,9-epoxide, a not previously described bioconversion product of limonene. With (4R)-limo

  12. Novel multispecies microbial consortia involved in lignocellulose and 5-hydroxymethylfurfural bioconversion

    NARCIS (Netherlands)

    Jiménez Avella, Diego; Korenblum, Elisa; van Elsas, Jan Dirk

    2014-01-01

    To develop a targeted metagenomics approach for the analysis of novel multispecies microbial consortia involved in the bioconversion of lignocellulose and furanic compounds, we applied replicated sequential batch aerobic enrichment cultures with either pretreated or untreated wheat straw as the sour

  13. Optimising the anaerobic co-digestion of urban organic waste using dynamic bioconversion mathematical modelling

    DEFF Research Database (Denmark)

    Fitamo, Temesgen Mathewos; Boldrin, Alessio; Dorini, G.

    2016-01-01

    strategies for controlling and optimising the co-digestion process. The model parameters were maintained in the same way as the original dynamic bioconversion model, albeit with minor adjustments, to simulate the co-digestion of food and garden waste with mixed sludge from a wastewater treatment plant...

  14. Bio-conversion of apple pomace into ethanol and acetic acid: Enzymatic hydrolysis and fermentation.

    Science.gov (United States)

    Parmar, Indu; Rupasinghe, H P Vasantha

    2013-02-01

    Enzymatic hydrolysis of cellulose present in apple pomace was investigated using process variables such as enzyme activity of commercial cellulase, pectinase and β-glucosidase, temperature, pH, time, pre-treatments and end product separation. The interaction of enzyme activity, temperature, pH and time had a significant effect (Pfermented using Saccharomyces cerevisae yielding 19.0g ethanol/100g DM. Further bio-conversion using Acetobacter aceti resulted in the production of acetic acid at a concentration of 61.4g/100g DM. The present study demonstrates an improved process of enzymatic hydrolysis of apple pomace to yield sugars and concomitant bioconversion to produce ethanol and acetic acid.

  15. Comparative study of Chinese and Hindu bioconversion units; Estudo comparativo de biodigestores modelos indiano e chines

    Energy Technology Data Exchange (ETDEWEB)

    Lucas Junior, Jorge de

    1987-12-01

    The kinds of anaerobic bioconversion units that are prevalent in the world are based on the chinese and hindu models. This work perform a comparison between this models, to permit an option for one model to another. The assays were developed with stock through daily and weekly loads, where information was gathered which allowed them to conclude as to the performance of bioconversion units built according to the hindu and chinese models, giving emphasis to those which refer to quantity of the biogas and quality of the effluents produced, as well as the influences of outside temperatures, of the air and the soil, about the temperature of the medium in fermentation. (author). 27 figs., 26 tabs., 66 refs

  16. Preliminary investigations into the bioconversion of gamma irradiated agricultural waste by Pleurotus spp.

    Science.gov (United States)

    Gbedemah, C. M.; Obodai, M.; Sawyerr, L. C.

    1998-06-01

    The application of gamma irradiation for pretreatment of lignocellulosic materials for their hydrolysis and to increase their digestibility for rumen animal have been reported in the literature. Gamma irradiation of corn stover in combination with sodium hydroxide for bioconversion of polysaccharide into protein by Pleurotus spp has also been reported. In this study experiments were designed to find out whether gamma radiation could serve both as a decontaminating agent as well as hydrolytic agent of sawdust for the bioconversion of four varieties of Pleurotus spp. Preliminary results indicate that a dose of 20kGy of gamma irradiation increase the yield of Pleurotus eous var ET-8 whilst decreasing the yield of other varieties.

  17. [Biodegradation of Cellulose-Containing Substrates by Micromycetes Followed by Bioconversion into Biogas].

    Science.gov (United States)

    Prokudina, L I; Osmolovskii, A A; Egorova, M A; Malakhova, D V; Netrusov, A I; Tsavkelova, E A

    2016-01-01

    The ability of micromycetes Trichoderma viride and Aspergillus terreus to decompose the cellulose-containing substrates was studied. Office paper and cardboard, as well as a paper mixture, were found to be the most hydrolyzable. The cellulolytic activity of T. viride was 2-3 times higher than that of A. terreus; the highest values of 0.80 and 0.73 U/mLwere obtained from office paper and the paper mixture, respectively. The micromycete cultivation conditions (composition of culture medium, sucrose cosubstrate addition, seeding method) and the conditions of the fungus biomass treatment for its subsequent bioconversion into biogas by anaerobic microbial communities were optimized. It was shown that pretreatment improves the efficiency of biogas production from lignocellulosic materials under seeding with microbial community of bovine animal manure. After pretreatment of the Jerusalem artichoke phytomass (stems and leaves) and its subsequent bioconversion into biogas by methanogenic community, the biogas yield was increased by 1.5 times.

  18. Multidisciplinary research program directed toward utilization of solar energy through bioconversion of renewable resources. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Finnerty, W. R.

    1976-07-01

    Progress is reported in four research areas of solar bioconversion. The first program deals with the genetic selection of superior trees, physiological basis of vigor, tissue culture, haploid cell lines, and somatic hybridization. The second deals with the physiology of paraquat-induced oleoresin biogenesis. Separate abstracts were prepared for the other two program areas: biochemical basis of paraquat-induced oleoresin production in pines and biochemistry of methanogenesis. (JSR)

  19. Transcriptomic study for screening genes involved in the oxidative bioconversions of Streptomyces avermitilis.

    Science.gov (United States)

    Kim, Hyo-Jeong; Choi, Kwon-Young; Jung, Da-Hye; Jung, Joon-Young; Jung, Eunok; Yang, Yung-Hun; Kim, Byung-Gee; Oh, Min-Kyu

    2013-11-01

    Streptomyces avermitilis is a well known organism producing avermectin antibiotics, and has been utilized as an industrial host for oxidation bioconversion processes. Recently, gene screening strategies related to bioconversions have received much focus, as attempts are made to optimize oxidation and biodegradation pathways to maximize yield and productivity. Here, we have demonstrated the oxidative metabolisms of three molecules, daidzein, p-coumaric acid and mevastatin, where S. avermitilis converted each substrate to 3',4',7-trihydroxyisoflavone, caffeic acid and hydroxyl-mevastatin to yield 9.3, 32.5 and 15.0 %, respectively. Microarray technology was exploited to investigate genome-wide analysis of gene expression changes, which were induced upon the addition of each substrate. Cytochrome P450 hydroxylases (pteC, cyp28 and olmB), diooxygenases (xylE, cdo1 and putatives) and LuxAB-like oxygenase were identified. One of them, cyp28, was indeed a gene encoding P450 hydroxylase responsible for the oxidative reaction of daidzein. Furthermore, possible electron transfer chain (fdrC → pteE → pteC) supporting cytochrome P450 dependent hydroxylation of daidzein has been suggested based on the interpretation of expression profiles. The result provided a potential application of transcriptomic study on uncovering enzymes involved in oxidative bioconversions of S. avermitilis.

  20. Bioconversion of R-(+-limonene to perillic acid by the yeast Yarrowia lipolytica

    Directory of Open Access Journals (Sweden)

    Maria Antonieta Ferrara

    2013-12-01

    Full Text Available Perillyl derivatives are increasingly important due to their flavouring and antimicrobial properties as well as their potential as anticancer agents. These terpenoid species, which are present in limited amounts in plants, may be obtained via bioconversion of selected monoterpene hydrocarbons. In this study, seventeen yeast strains were screened for their ability to oxidize the exocyclic methyl group in the p-menthene moiety of limonene into perillic acid. Of the yeast tested, the highest efficiency was observed for Yarrowia lipolytica ATCC 18942. The conversion of R (+-limonene by Y. lipolytica was evaluated by varying the pH (3 to 8 and the temperature (25 to 30 ºC in a reaction medium containing 0.5% v/v limonene and 10 gµL of stationary phase cells (dry weight. The best results, corresponding to 564 mgµL of perillic acid, were obtained in buffered medium at pH 7.1 that was incubated at 25 ºC for 48 h. The stepwise addition of limonene increased the perillic acid concentration by over 50%, reaching 855 mgµL, whereas the addition of glucose or surfactant to the reaction medium did not improve the bioconversion process. The use of Y. lipolytica showed promise for ease of further downstream processing, as perillic acid was the sole oxidised product of the bioconversion reaction. Moreover, bioprocesses using safe and easy to cultivate yeast cells have been favoured in industry.

  1. Bioconversion of R-(+)-limonene to perillic acid by the yeast Yarrowia lipolytica

    Science.gov (United States)

    Ferrara, Maria Antonieta; Almeida, Débora S.; Siani, Antonio C.; Lucchetti, Leonardo; Lacerda, Paulo S.B.; Freitas, André; Tappin, Marcelo R.R.; Bon, Elba P.S.

    2013-01-01

    Perillyl derivatives are increasingly important due to their flavouring and antimicrobial properties as well as their potential as anticancer agents. These terpenoid species, which are present in limited amounts in plants, may be obtained via bioconversion of selected monoterpene hydrocarbons. In this study, seventeen yeast strains were screened for their ability to oxidize the exocyclic methyl group in the p-menthene moiety of limonene into perillic acid. Of the yeast tested, the highest efficiency was observed for Yarrowia lipolytica ATCC 18942. The conversion of R (+)-limonene by Y. lipolytica was evaluated by varying the pH (3 to 8) and the temperature (25 to 30 °C) in a reaction medium containing 0.5% v/v limonene and 10 g/L of stationary phase cells (dry weight). The best results, corresponding to 564 mg/L of perillic acid, were obtained in buffered medium at pH 7.1 that was incubated at 25 °C for 48 h. The stepwise addition of limonene increased the perillic acid concentration by over 50%, reaching 855 mg/L, whereas the addition of glucose or surfactant to the reaction medium did not improve the bioconversion process. The use of Y. lipolytica showed promise for ease of further downstream processing, as perillic acid was the sole oxidised product of the bioconversion reaction. Moreover, bioprocesses using safe and easy to cultivate yeast cells have been favoured in industry. PMID:24688495

  2. Antibacterial potency of housefly larvae extract from sewage sludge through bioconversion

    Institute of Scientific and Technical Information of China (English)

    Chaocheng Zheng; Lixiang Zhou

    2013-01-01

    Use of the fly to convert sewage sludge into nutrient-rich soil conditioner and amendment is an attractive approach for sludge bioconversion.During this process,fecal coliforms,an indicating pathogen,in sludge were reduced to 5.3 × 102 most probable number /g dry solid from initial 3.32 × 106 MPN/g dry solid.It was also found that the extract of larvae grown in sludge during bioconversion have an observable inhibitory effect against bacteria compared to larvae grown in wheat bran as measured by minimum bacterial concentration tests.In vitro antimicrobial assay tests over time also showed that the extract had strong inhibitory efficiencies of ca.99% against Bacillus cereus,Staphylococcus aureus,Escherichia coli,Pseudomonas aeruginosa,and Serratia marcescens,while the efficiency was 69% and 57% against Bacillus subtilis and Klebsiella pneumoniae,respectively.The observed pathogenic bacterial cell membrane damage was found to be responsible for the phenomenon mentioned above,with nuclear acids leaching out quickly and alkaline phosphatase increasing in the outer membrane,followed by an increase of β-galactosidase in the inner membrane.Clearly,housefly larvae extract from sewage sludge through bioconversion possesses antibacterial potency against pathogenic bacteria.

  3. COST-BENEFIT ANALYSIS OF BIOCONVERSION NEUFCHATEL WHEY INTO RECTIFIED ETHANOL AND ORGANIC LIQUID FERTILIZER IN SEMI PILOT SCALE

    Directory of Open Access Journals (Sweden)

    Gemilang Lara UTAMA

    2015-10-01

    Full Text Available Aims of the study was to determine the cost-benefit analysis in neufchatel whey bioconversion into rectified ethanol and organic liquid fertilizer. Bioconversion whey into rectified ethanol and organic liquid fertilizer has shown great potential as a way to reduce the pollution resulting from cheese-making process. Semi pilot scale experiment was done to ferment 5 L neufchatel whey using 5% K. lactis at 33°C for 24 h in semi anaerobic plastic container without agitation and then distilled into 96.2% purity. Data collected and analyzed descriptively related to benefit cost ratio/BCR, net present value/NPV and internal rate returns/IRR. The result showed that semi pilot scale bioconversion of neufchatel whey resulting in 106.42 ml rectified ethanol and 4404.22 ml distillery residue. Economic benefit could achieved by the support of distillery residue sales as organic liquid fertilizer.

  4. Bioconversion of lactose/whey to fructose diphosphate with recombinant Saccharomyces cerevisiae cells

    Energy Technology Data Exchange (ETDEWEB)

    Compagno, C.; Tura, A.; Ranzi, B.M.; Martegani, E. (Univ. di Milano (Italy))

    1993-07-01

    Genetically engineered Saccharomyces cerevisiae strains that express Escherichia coli [beta]-galactosidase gene are able to bioconvert lactose or whey into fructose-1,6-diphosphate (FDP). High FDP yields from whey were obtained with an appropriate ratio between cell concentration and inorganic phosphate. The biomass of transformed cells can be obtained from different carbon sources, according to the expression vector bearing the lacZ gene. The authors showed that whey can be used as the carbon source for S. cerevisiae growth and as the substrate for bioconversion to fructose diphosphate.

  5. European bioconversion projects and realizations for macroalgal biomass: Saint-Cast-Le-Guildo (France) experiment

    OpenAIRE

    Morand, Ph.; Charlier, R.H.; Mazé, J.

    1990-01-01

    Proliferation of macroalgae is a world-wide problem with 50,000 m3 of drift Ulva harvested per year in Brittany and about 1.0 to 1.2 million tons growing in the Venice lagoon. This biomass may be treated by bioconversion (aerobic or anaerobic fermentation) to give useful products (gas, fertilizers or others) and to remove a source of environmental pollution. Such a treatment also may be applied to cultivated or harvested seaweds and to seaweed industry residues.Studies of seaweed methanizatio...

  6. Comparison of different cellulolytic fungi for bioconversion of apple distillery waste

    Energy Technology Data Exchange (ETDEWEB)

    Friedrich, J.; Cimerman, A.; Perdih, A.

    1986-08-01

    The suitability of three ascomycetous fungi, Aspergillus niger, A. awamori and Trichoderma reesei, as well as two basidiomycetes, Pleurotus ostreatus and Phanerochaete chrysosporium, for bioconversion of apple distillery slop was compared. Trichoderma and Phanerochaete degraded raw fibres by 20%, producing filter cakes with 17% to 22% raw protein contents. Aspergillus spp. were superior in filtration time and COD reduction and were of the same efficiency in protein synthesis as Trichoderma and Phanerochaete, but did not degrade fibres. Pleurotus ostreatus did not degrade lignin under fermentation conditions used and could not compete with other fungi due to its slower growth.

  7. Novel bioconversion of wheat straw to bio-organic fertilizer in a solid-state bioreactor.

    Science.gov (United States)

    Chen, Hongzhang; Sun, Fubao

    2007-03-01

    In order to increase the eco-efficiency and overall availability of naturally renewable resource, the novel bioconversion of steam-exploded wheat straw to bio-organic fertilizer containing N(2)-fixer, P and K solubilizers was investigated. The conversion was performed in solid-state fermentation (SSF) with periodic air-forced pressure oscillation (PAPO). The results showed that SSF-PAPO was competitive with the conventional solid-state fermentation (cSSF) in biomass accumulation and wheat straw digestion. With solid-liquid ratio 1:3, microbial biomass production at 72 h was high up to 2 x 10(11) cfu g(-1), nearly twice as that in cSSF. The degradation rate of cellulose, hemicellulose and lignin after fermentation in SSF-PAPO reached 48.57 +/- 10.66, 84.77 +/- 2.75 and 2.15 +/- 10.11, respectively, which was greater than that of 29.30 +/- 10.28%, 33.47 +/- 4.85% and 0.53 +/- 9.07% in cSSF, correspondingly. The SSF-PAPO system displayed unique advantage, by a novel gas phase control strategy on gas concentration and heat gradient, on the bioconversion of wheat straw to the bio-organic fertilizer.

  8. Identifying the shared metabolic objectives of glycerol bioconversion in Klebsiella pneumoniae under different culture conditions.

    Science.gov (United States)

    Xu, Gongxian; Li, Caixia

    2017-03-18

    This paper addresses the problem of identifying the shared metabolic objectives of glycerol bioconversion in Klebsiella pneumoniae for production of 1,3-propanediol (1,3-PD) under different culture conditions. To achieve this goal, we propose a multi-level programming model. This model includes three optimization problems, where the constraint region of the first level problem is implicitly determined by the other two optimization problems. The optimized objectives of the first and second level problems are to minimize the set of fluxes that are of major importance to glycerol metabolism and the difference between the observed fluxes and those computed by the model, respectively. The third level problem in the proposed multi-level programming simultaneously solves a set of flux balance analysis (FBA) models. A method is proposed to solve efficiently the presented multi-level programming problem. In this method, we first transform the proposed multi-level problem into a bi-level problem by applying the dual theory of linear programming to the FBA models of the third level. Next, the optimal solution of the above bi-level problem is obtained by iteratively solving a sequence of mixed integer programming problems. Optimization results reveal that the proposed method can identify the shared metabolic objectives of glycerol bioconversion in Klebsiella pneumoniae under three groups of experimental data.

  9. Bioconversion of pinoresinol into matairesinol by use of recombinant Escherichia coli.

    Science.gov (United States)

    Kuo, Han-Jung; Wei, Zhi-Yu; Lu, Pei-Chun; Huang, Pung-Ling; Lee, Kung-Ta

    2014-05-01

    Lignans, a class of dimeric phenylpropanoid derivative found in plants, such as whole grains and sesame and flax seeds, have anticancer activity and can act as phytoestrogens. The lignans secoisolariciresinol and matairesinol can be converted in the mammalian proximal colon into enterolactone and enterodiol, respectively, which reduce the risk of breast and colon cancer. To establish an efficient bioconversion system to generate matairesinol from pinoresinol, the genes encoding pinoresinol-lariciresinol reductase (PLR) and secoisolariciresinol dehydrogenase (SDH) were cloned from Podophyllum pleianthum Hance, an endangered herb in Taiwan, and the recombinant proteins, rPLR and rSDH, were expressed in Escherichia coli and purified. The two genes, termed plr-PpH and sdh-PpH, were also linked to form two bifunctional fusion genes, plr-sdh and sdh-plr, which were also expressed in E. coli and purified. Bioconversion in vitro at 22°C for 60 min showed that the conversion efficiency of fusion protein PLR-SDH was higher than that of the mixture of rPLR and rSDH. The percent conversion of (+)-pinoresinol to matairesinol was 49.8% using PLR-SDH and only 17.7% using a mixture of rPLR and rSDH. However, conversion of (+)-pinoresinol by fusion protein SDH-PLR stopped at the intermediate product, secoisolariciresinol. In vivo, (+)-pinoresinol was completely converted to matairesinol by living recombinant E. coli expressing PLR-SDH without addition of cofactors.

  10. Bioconversion of Airborne Methylamine by Immobilized Recombinant Amine Oxidase from the Thermotolerant Yeast Hansenula polymorpha

    Directory of Open Access Journals (Sweden)

    Sasi Sigawi

    2014-01-01

    Full Text Available Aliphatic amines, including methylamine, are air-pollutants, due to their intensive use in industry and the natural degradation of proteins, amino acids, and other nitrogen-containing compounds in biological samples. It is necessary to develop systems for removal of methylamine from the air, since airborne methylamine has a negative effect on human health. The primary amine oxidase (primary amine : oxygen oxidoreductase (deaminating or amine oxidase, AMO; EC 1.4.3.21, a copper-containing enzyme from the thermotolerant yeast Hansenula polymorpha which was overexpressed in baker’s yeast Saccharomyces cerevisiae, was tested for its ability to oxidize airborne methylamine. A continuous fluidized bed bioreactor (CFBR was designed to enable bioconversion of airborne methylamine by AMO immobilized in calcium alginate (CA beads. The results demonstrated that the bioreactor with immobilized AMO eliminates nearly 97% of the airborne methylamine. However, the enzymatic activity of AMO causes formation of formaldehyde. A two-step bioconversion process was therefore proposed. In the first step, airborne methylamine was fed into a CFBR which contained immobilized AMO. In the second step, the gas flow was passed through another CFBR, with alcohol oxidase from the yeast H. polymorpha immobilized in CA, in order to decompose the formaldehyde formed in the first step. The proposed system provided almost total elimination of the airborne methylamine and the formaldehyde.

  11. Optimising the anaerobic co-digestion of urban organic waste using dynamic bioconversion mathematical modelling.

    Science.gov (United States)

    Fitamo, T; Boldrin, A; Dorini, G; Boe, K; Angelidaki, I; Scheutz, C

    2016-12-01

    Mathematical anaerobic bioconversion models are often used as a convenient way to simulate the conversion of organic materials to biogas. The aim of the study was to apply a mathematical model for simulating the anaerobic co-digestion of various types of urban organic waste, in order to develop strategies for controlling and optimising the co-digestion process. The model parameters were maintained in the same way as the original dynamic bioconversion model, albeit with minor adjustments, to simulate the co-digestion of food and garden waste with mixed sludge from a wastewater treatment plant in a continuously stirred tank reactor. The model's outputs were validated with experimental results obtained in thermophilic conditions, with mixed sludge as a single substrate and urban organic waste as a co-substrate at hydraulic retention times of 30, 20, 15 and 10 days. The predicted performance parameter (methane productivity and yield) and operational parameter (concentration of ammonia and volatile fatty acid) values were reasonable and displayed good correlation and accuracy. The model was later applied to identify optimal scenarios for an urban organic waste co-digestion process. The simulation scenario analysis demonstrated that increasing the amount of mixed sludge in the co-substrate had a marginal effect on the reactor performance. In contrast, increasing the amount of food waste and garden waste resulted in improved performance.

  12. Integration of bioconversion and downstream processing: starch hydrolysis in an aqueous two-phase system.

    Science.gov (United States)

    Larsson, M; Arasaratnam, V; Mattiasson, B

    1989-02-05

    Integration of bioconversion and the first step(s) of down stream processing can be used as a means to increase the productivity of bioprocesses. This integration also gives the possibility to run the bioconversion in a continuous mode. We demonstrate the use of an aqueous two-phase system in combination with ultrafiltration to accomplish this. Conversion of native starch to glucose by alpha-amylase and glucoamylase was carried out in an aqueous two-phase system in connection with a membrane filtration unit. In this way, a continuous stream of glucose in buffer solution was obtained; the phase-forming polymers as well as the starch-degrading enzymes were recycled, and clogging of the ultrafiltration membrane was avoided. The process was carried out continuously in a mixer-settler reactor for a period of 8 days. The enzyme activities in the top and bottom phases and in the mixing chamber were monitored intermittently throughout the experiment. The optimum pH, temperature, and ionic strength for the activity of the enzyme mixture were determined. The settling time of phase systems containing varying amounts of PEG, crude dextran, and solid starch was studied. The activity and stability of enzyme mixtures was studied both in buffer medium and in the medium containing the polymers. The enzymes were found to be more active and stable in medium containing polymers than in the buffer solutions.

  13. Biofilm reactors for industrial bioconversion processes: employing potential of enhanced reaction rates

    Directory of Open Access Journals (Sweden)

    Karcher Patrick

    2005-08-01

    Full Text Available Abstract This article describes the use of biofilm reactors for the production of various chemicals by fermentation and wastewater treatment. Biofilm formation is a natural process where microbial cells attach to the support (adsorbent or form flocs/aggregates (also called granules without use of chemicals and form thick layers of cells known as "biofilms." As a result of biofilm formation, cell densities in the reactor increase and cell concentrations as high as 74 gL-1 can be achieved. The reactor configurations can be as simple as a batch reactor, continuous stirred tank reactor (CSTR, packed bed reactor (PBR, fluidized bed reactor (FBR, airlift reactor (ALR, upflow anaerobic sludge blanket (UASB reactor, or any other suitable configuration. In UASB granular biofilm particles are used. This article demonstrates that reactor productivities in these reactors have been superior to any other reactor types. This article describes production of ethanol, butanol, lactic acid, acetic acid/vinegar, succinic acid, and fumaric acid in addition to wastewater treatment in the biofilm reactors. As the title suggests, biofilm reactors have high potential to be employed in biotechnology/bioconversion industry for viable economic reasons. In this article, various reactor types have been compared for the above bioconversion processes.

  14. Bioconversion of methyl ricinoleate to 4-hydroxy-decanoic acid and to gamma-decalactone by yeasts of the genus Candida.

    Science.gov (United States)

    Endrizzi, A; Belin, J M

    1995-01-01

    The capacity of several strains of yeasts to do the bioconversion of methyl ricinoleate into gamma-decalactone, was studied in a medium containing this methylic ester of fatty acid as sole carbon source. Amongst the strains which are able to do this bioconversion, two types of behaviour are observed: some of the strains produce gamma-decalactone during all the incubation in bioconversion medium while others produce this aroma compound very quickly and then consume it fast too. The tested strains produce at the same time gamma-decalactone and the corresponding acid form (4-hydroxy-decanoic acid), and this, in variable proportions.

  15. Bioconversion éco-compatible de triterpénoïdes par des bactéries immobilisées sur Luffa cylindrica

    OpenAIRE

    Bou Saab, Hamid

    2011-01-01

    One of the major advantages of using biocatalysts in organic synthesis is that water constitutes the reaction medium. However, water becomes a serious problem when bioconversion deals with lipophilic compounds, in particular those poorly soluble in water such as sterols. Bioconversion of lipophilic compounds depends on the close contact between the hydrophobic substrate and the biocatalyst. Increasing this contact requires usually the use of huge amounts of chemical which are often toxic, fla...

  16. The Bioconversion of Red Ginseng Ethanol Extract into Compound K by Saccharomyces cerevisiae HJ-014.

    Science.gov (United States)

    Choi, Hak Joo; Kim, Eun A; Kim, Dong Hee; Shin, Kwang-Soo

    2014-09-01

    A β-glucosidase producing yeast strain was isolated from Korean traditional rice wine. Based on the sequence of the YCL008c gene and analysis of the fatty acid composition, the isolate was identified as Saccharomyces cerevisiae strain HJ-014. S. cerevisiae HJ-014 produced ginsenoside Rd, F2, and compound K from the ethanol extract of red ginseng. The production was increased by shaking culture, where the bioconversion efficiency was increased 2-fold compared to standing culture. The production of ginsenoside F2 and compound K was time-dependent and thought to proceed by the transformation pathway of: red ginseng extract→Rd→F2→compound K. The optimum incubation time and concentration of red ginseng extract for the production of compound K was 96 hr and 4.5% (w/v), respectively.

  17. Direct bioconversion of raw corn stalk to hydrogen by a new strain Clostridium sp. FS3.

    Science.gov (United States)

    Song, Zhao-Xia; Li, Xiao-Hu; Li, Wei-Wei; Bai, Yan-Xia; Fan, Yao-Ting; Hou, Hong-Wei

    2014-04-01

    A new strain FS3 which could achieve an efficient bioconversion of raw corn stalk to hydrogen had been isolated from anaerobic acclimated sludge, and identified as Clostridium butyricum on the basis of a series of physiological and biochemical experiments and 16S rDNA gene sequence. The strain could utilize various carbon sources to produce hydrogen. On the basis of single-factor experiments, the response surface methodology (RSM) was performed to optimize the media for hydrogen production. The maximum hydrogen yield of 92.9ml/g was observed under the optimal conditions: 20g/l raw corn stalk, 1.76g/l NH4HCO3, 0.91g/l KH2PO4 and 10.4ml/l nutrient solution. This finding opens a new avenue for direct conversion of raw cellulosic biomass to bio-hydrogen.

  18. Fibrous Agricultural Biomass as a Potential Source for Bioconversion to Vanillic Acid

    Directory of Open Access Journals (Sweden)

    Pei-Ling Tang

    2014-01-01

    Full Text Available This study was conducted to assess the potential of six fibrous agricultural residues, namely, oil palm empty fruit bunch fiber (OPEFBF, coconut coir fiber (CCF, pineapple peel (PP, pineapple crown leaves (PCL, kenaf bast fiber (KBF, and kenaf core fiber (KCF, as a source of ferulic acid and phenolic compounds for bioconversion into vanillic acid. The raw samples were pretreated with organosolv (NaOH-glycerol and alkaline treatment (NaOH, to produce phenol-rich black liquor. The finding showed that the highest amount of phenolic compounds and ferulic acid was produced from CCF and PP, respectively. This study also found that organosolv treatment was the superior method for phenolic compound extraction, whereas alkaline treatment was the selective method for lignin extraction. Vanillic acid production by Aspergillus niger I-1472 was only observed when the fermentation broth was fed with liquors from PP and PCL, possibly due to the higher levels of ferulic acid in those samples.

  19. Evaluation energy efficiency of bioconversion knot rejects to ethanol in comparison to other thermochemically pretreated biomass.

    Science.gov (United States)

    Wang, Zhaojiang; Qin, Menghua; Zhu, J Y; Tian, Guoyu; Li, Zongquan

    2013-02-01

    Rejects from sulfite pulp mill that otherwise would be disposed of by incineration were converted to ethanol by a combined physical-biological process that was comprised of physical refining and simultaneous saccharification and fermentation (SSF). The energy efficiency was evaluated with comparison to thermochemically pretreated biomass, such as those pretreated by dilute acid (DA) and sulfite pretreatment to overcome recalcitrance of lignocelluloses (SPORL). It was observed that the structure deconstruction of rejects by physical refining was indispensable to effective bioconversion but more energy intensive than that of thermochemically pretreated biomass. Fortunately, the energy consumption was compensated by the reduced enzyme dosage and the elevated ethanol yield. Furthermore, adjustment of disk-plates gap led to reduction in energy consumption with negligible influence on ethanol yield. In this context, energy efficiency up to 717.7% was achieved for rejects, much higher than that of SPORL sample (283.7%) and DA sample (152.8%).

  20. Production of Cellulase from Oil Palm Biomass as Substrate by Solid State Bioconversion

    Directory of Open Access Journals (Sweden)

    Md. Z. Alam

    2005-01-01

    Full Text Available Solid state bioconversion (SSB of lignocellulosic material oil palm biomass (OPB generated from palm oil industries as waste was conducted by evaluating the enzyme production through filamentous fungus in lab-scale experiment. OPB in the form of empty fruit bunches (EFB was used as the solid substrate and treated with the fungus Trichoderma harzianum to produce cellulase. The results presented in this study revealed that the higher cellulase activity of 0.0413 unit was achieved at the day 3 of fermentation. While the optimum study indicated the enzyme production of 0.0433 unit with moisture content of 50%, 0.0413 unit with 5% v/w of inoculum size and 0.0413 unit with co-substrate concentration of 2% (w/w at days 9, 9 and 12 of fungal treatment, respectively. The parameters glucosamine and reducing sugar were observed to evaluate the growth and substrate utilization in the experiment.

  1. Efficacy of bioconversion of paper mill bamboo sludge and lime waste by composting and vermiconversion technologies.

    Science.gov (United States)

    Sahariah, B; Sinha, I; Sharma, P; Goswami, L; Bhattacharyya, P; Gogoi, N; Bhattacharya, S S

    2014-08-01

    Paper mill bamboo sludge (PMBS) and Paper mill lime waste (PMLW) are extensively produced as solid wastes in paper mills. Untreated PMBS and PMLW contain substantial amount of heavy metals (Zn, Pb, Ni, Cd, Cr) in soluble forms. Efficiency of vermiconversion and aerobic composting with these wastes is reported here. Adopted bioconversion systems enhanced the availability of some essential nutrients (N, P, K and Zn) in various combinations of cow dung (CD) with PMBS and PMLW. Colonization of nitrogen fixing bacteria and phosphate solubilizing bacteria considerably intensified under the vermiconversion system. Moreover, significant metal detoxification occurred due to vermiconversion. Various combinations of bioconverted PMBS and PMLW were applied to tissue cultured bamboo (Bambusa tulda) and chilli (Capsicum annum). Accelerated nutrient uptake coupled with improved soil quality resulted in significant production of chilli. Furthermore, vermiconverted PMBS+CD (1:1) and PMLW+CD (1:3) confirmed as potential enriching substrate for tissue cultured bamboo.

  2. Isolation and structure elucidation of rebaudioside D2 from bioconversion reaction of rebaudioside A to rebaudioside D.

    Science.gov (United States)

    Prakash, Indra; Bunders, Cynthia; Devkota, Krishna P; Charan, Romila D; Ramirez, Catherine; Parikh, Maunik; Markosyan, Avetik

    2014-08-01

    We report the isolation and complete structure of an isomer of rebaudioside D, known as rebaudioside D2. This novel steviol glycoside was isolated from a bioconversion reaction of rebaudioside A to rebaudioside D. Rebaudioside D2 possesses a relatively rare 1 --> 6 sugar linkage, which was discovered by extensive analysis of NMR (1H, 13C, COSY, HSQC-DEPT, HMBC, 1D TOCSY and NOESY) and mass spectral data.

  3. [Bioconversion of conjugated linoleic acid by resting cells of Lactobacillus plantarum ZS2058 in potassium phosphate buffer system].

    Science.gov (United States)

    Niu, Xiao-yan; Chen, Wei; Tian, Feng-wei; Zhao, Jian-xin; Zhang, Hao

    2007-04-01

    Lactobacillus plantarum ZS2058, which was screened from the Chinese traditional fermented vegetable, has the capacity to convert the linoleic acid (LA) into conjugated linoleic acid (CLA). Some specific isomers of CLA with potentially beneficial physiological and anticarcinogenic effects, were efficiently produced from free linoleic acid by washed cells of Lactobacillus plantarum ZS2058 under aerobic conditions. The produced CLA isomers are identified as the mixture of cis-9, trans-ll-octadecadienoic acid (CLA1) trans-10, cis-12-octadecadienoic acid (CLA2), 96.4% of which is CLA1. The washed cells of Lactobacillus plantarum ZS2058 producing high levels of c9, t11-CLA were obtained by cultivated in MRS media containing 0.5 mg/mL linoleic acid, indicating that the enzyme system for CLA production is induced by linoleic acid. After a 24-hour bioconversion at 37 degrees C with shaking (120 r/min), 312.4 microg/mL c9, t11-CLA is produced. And after a 36-hour bioconversion, the content of c9, t11-CLA decreases while hydroxy-octadecaenoic acid increases. In addition, the c9, t11-CLA isomer can be transformed to hydroxy- octadecaenoic acid when the mixed CLA (c9, t11-CLA and t10, c12-CLA) were used as the substrate, which suggests that c9, t11-CLA is one of the intermediates of the bioconversion products from free LA by washed cells of Lactobacillus plantarum ZS2058.

  4. Stabilization of collagen through bioconversion: An insight in protein-protein interaction.

    Science.gov (United States)

    Usharani, Nagarajan; Jayakumar, Gladstone Christopher; Kanth, Swarna Vinodh; Rao, Jonnalagadda Raghava

    2014-08-01

    Collagen is a natural protein, which is used as a vital biomaterial in tissue engineering. The major concern about native collagen is lack of its thermal stability and weak resistance to proteolytic degradation. In this scenario, the crosslinking compounds used for stabilization of collagen are mostly of chemical nature and exhibit toxicity. The enzyme mediated crosslinking of collagen provides a novel alternative, nontoxic method for stabilization. In this study, aldehyde forming enzyme (AFE) is used in the bioconversion of hydroxylmethyl groups of collagen to formyl groups that results in the formation of peptidyl aldehyde. The resulted peptidyl aldehyde interacts with bipolar ions of basic amino acid residues of collagen. Further interaction leads to the formation of conjugated double bonds (aldol condensation involving the aldehyde group of peptidyl aldehyde) within the collagen. The enzyme modified collagen matrices have shown an increase in the denaturation temperature, when compared with native collagen. Enzyme modified collagen membranes exhibit resistance toward collagenolytic activity. Moreover, they exhibited a nontoxic nature. The catalytic activity of AFE on collagen as a substrate establishes an efficient modification, which enhances the structural stability of collagen. This finds new avenues in the context of protein-protein stabilization and discovers paramount application in tissue engineering.

  5. The Preparation of Bioimprinted Whole-cell Biocatalyst and Its Application in Bioconversion of Biodiesel

    Directory of Open Access Journals (Sweden)

    Meiling Chen

    2015-08-01

    Full Text Available Biodiesel has attracted considerable attention as an environmentally friendly alternative fuel. Lipase is the most popular enzyme for biodiesel production and immobilization has been deployed to improve enzyme stability and reusability. Exploitation of high activity lipase is the key point for biodiesel production. Whole-cell biocatalysts have been applied in the biosynthesis of biodiesel and bioimprinting is a promising approach for enzyme performances improvement. In this study, based on the S. cerevisiae cell-surface display system with &alpha-agglutinin as anchor, a whole-cell biocatalyst of codon-optimized Rhizopus oryzae lipase was constructed and bioimprinted with oleic acid, gaining 5-fold increase on enzymatic activity in the alcoholysis of soybean oil to biodiesel. Moreover, the conversion of FAME was up to 95.45±2.73% after a 27-h reaction at 60°C. Our results indicated that combining bioimprinting with yeast display technique to prepare whole-cell biocatalyst could result in potential enzymes for bioconversion of biodiesel in organic solvents.

  6. Bioconversion of coal-derived synthesis gas to liquid fuels. [Butyribacterium methylotrophicum

    Energy Technology Data Exchange (ETDEWEB)

    Jain, M.K.

    1991-01-01

    The use of coal-derived synthesis gas as an industrial feedstock for production of fuels and chemicals has become an increasingly attractive alternative to present petroleum-based chemicals production. However, one of the major limitations in developing such a process is the required removal of catalyst poisons such as hydrogen sulfide (H{sub 2}S), carbonyl sulfide (COS), and other trace contaminants from the synthesis gas. Purification steps necessary to remove these are energy intensive and add significantly to the production cost, particularly for coals having a high sulfur content such as Illinois coal. A two-stage, anaerobic bioconversion process requiring little or no sulfur removal is proposed, where in the first stage the carbon monoxide (CO) gas is converted to butyric and acetic acids by the CO strain of Butyribacterium methylotrophicum. In the second stage, these acids along with the hydrogen (H{sub 2}) gas are converted to butanol, ethanol, and acetone by an acid utilizing mutant of Clostridium acetobutylicum. 18 figs., 18 tabs.

  7. Removal of heteroatoms and metals from heavy oils by bioconversion processes

    Energy Technology Data Exchange (ETDEWEB)

    Kaufman, E.N.

    1996-06-01

    Biocatalysts, either appropriate microorganisms or isolated enzymes, will be used in an aqueous phase in contact with the heavy oil phase to extract heteroatoms such as sulfur from the oil phase by bioconversion processes. Somewhat similar work on coal processing will be adapted and extended for this application. Bacteria such as Desulfovibrio desulfuricans will be studied for the reductive removal of organically-bound sulfur and bacteria such as Rhodococcus rhodochrum will be investigated for the oxidative removal of sulfur. Isolated bacteria from either oil field co-produced sour water or from soil contaminated by oil spills will also be tested. At a later time, bacteria that interact with organic nitrogen may also be studied. This type of interaction will be carried out in advanced bioreactor systems where organic and aqueous phases are contacted. One new concept of emulsion-phase contacting, which will be investigated, disperses the aqueous phase in the organic phase and is then recoalesced for removal of the contaminants and recycled back to the reactor. This program is a cooperative research and development program with the following companies: Baker Performance Chemicals, Chevron, Energy BioSystems, Exxon, Texaco, and UNOCAL. After verification of the bioprocessing concepts on a laboratory-scale, the end-product will be a demonstration of the technology at an industrial site. This should result in rapid transfer of the technology to industry.

  8. Bioconversion of high concentrations of hydrogen sulfide to elemental sulfur in airlift bioreactor.

    Science.gov (United States)

    Zytoon, Mohamed Abdel-Monaem; AlZahrani, Abdulraheem Ahmad; Noweir, Madbuli Hamed; El-Marakby, Fadia Ahmed

    2014-01-01

    Several bioreactor systems are used for biological treatment of hydrogen sulfide. Among these, airlift bioreactors are promising for the bioconversion of hydrogen sulfide into elemental sulfur. The performance of airlift bioreactors is not adequately understood, particularly when directly fed with hydrogen sulfide gas. The objective of this paper is to investigate the performance of an airlift bioreactor fed with high concentrations of H2S with special emphasis on the effect of pH in combination with other factors such as H2S loading rate, oxygen availability, and sulfide accumulation. H2S inlet concentrations between 1,008 ppm and 31,215 ppm were applied and elimination capacities up to 113 g H2S m(-3) h(-1) were achieved in the airlift bioreactor under investigation at a pH range 6.5-8.5. Acidic pH values reduced the elimination capacity. Elemental sulfur recovery up to 95% was achieved under oxygen limited conditions (DO bioreactor tolerated accumulated dissolved sulfide concentrations >500 mg/L at pH values 8.0-8.5, and near 100% removal efficiency was achieved. Overall, the resident microorganisms in the studied airlift bioreactor favored pH values in the alkaline range. The bioreactor performance in terms of elimination capacity and sulfur recovery was better at pH range 8-8.5.

  9. Scaling-up of complex whole-cell bioconversions in conventional and non-conventional media.

    Science.gov (United States)

    Marques, Marco P C; de Carvalho, Carla C C R; Cabral, Joaquim M S; Fernandes, Pedro

    2010-07-01

    The use of whole cells is becoming a more common approach in pharmaceutical and agrochemical industries in order to obtain pure compounds with fewer production steps, higher yields, and cleaner processes, as compared to those achieved with traditional strategies. Whole cells are often used as enzymes pools, in particular when multi-step reactions and/or co-factor regeneration are envisaged. Nonetheless, published information on the scale-up of such systems both in aqueous and in two-phase aqueous-organic systems is relatively scarce. The present work aims to evaluate suitable scale-up criteria in conventional and non-conventional medium for a whole-cell bioconversion that uses resting cells of Mycobacterium sp. NRRL B-3805 to cleave the side chain of beta-sitosterol, a poorly water-soluble substrate. The experiments were performed in 24-well microtiter plates and in 250 mL shaken flasks as orbital stirred systems, and in 300 mL stirred tanks as mechanically stirred systems. Results show that productivity yields were similar in all scales tested, when maintaining oxygen mass transfer coefficients constant in aqueous systems, or when maintaining constant volumetric power consumption in aqueous-organic two-phase systems.

  10. Consolidating biofuel platforms through the fermentative bioconversion of crude glycerol to butanol.

    Science.gov (United States)

    Johnson, Erin; Sarchami, Tahereh; Kießlich, Sascha; Munch, Garret; Rehmann, Lars

    2016-06-01

    Economic realities for the rising industrial biofuel production have changed substantially during the low oil price period starting in the mid 2010's. Increased competition requires the sector to increase productivity through the reduction of low-value by-products and full utilization of all value and energy stored in their respective feedstock. Biodiesel is produced commercially from substrates such as animal fat and vegetable oil, generating approximately 10 wt% crude glycerol as its main, currently underutilized, by-product. This crude glycerol is contaminated with catalyst, soap, free fatty acids, glycerides and methyl esters; hence only a small fraction enters the existing glycerol markets, while the purification costs for the majority of crude glycerol are simply too high. However, this presents a unique opportunity to generate additional value. One technical possibility is to use crude glycerol as a carbon source for butanol production, a compound of higher value and energy, a potential additive for gasoline and diesel fuels and bulk chemical commodity. Conversion facilities could be co-located with biodiesel plants, utilizing established infrastructure and adding significant value and productivity to the existing biodiesel industry. This review focuses on the current activities geared towards the bioconversion of crude glycerol to butanol.

  11. Bioconversion of 6-(N-methyl-N-phenyl)aminomethyl androstane steroids by Nocardioides simplex.

    Science.gov (United States)

    Sukhodolskaya, Galina; Fokina, Victoria; Shutov, Andrei; Nikolayeva, Vera; Savinova, Tatiana; Grishin, Yuri; Kazantsev, Alexey; Lukashev, Nikolay; Donova, Marina

    2017-02-01

    The newly synthesized (α/β)-diastereomers of 6-(N-methyl-N-phenyl)aminomethylandrost-4-ene-3,17-dione (5) and 6-(N-methyl-N-phenyl)aminomethylandrost-4-en-17β-ol-3-one (6) were firstly investigated as substrates for the whole cells of Nocardioides simplex VKM Ac-2033D in comparison with their unsubstituted analogs, - androst-4-ene-3,17-dione (1) and androst-4-en-17β-ol-3-one (2). 1(2)-Dehydroderivatives were identified as the major bioconversion products from all the substrates tested. When using the mixtures of (α/β)-stereoisomers of 5 and 6 as the substrates, only β-stereoisomers of the corresponding 1,4-diene-steroids were formed. Along with 1(2)-dehydrogenation, N. simplex VKM Ac-2033D promoted oxidation of the hydroxyl group at C-17 position of 6: both 6(α) and 6(β) were transformed to the corresponding 17-keto derivatives. No steroid core destruction was observed during the conversion of the 6-substituted androstanes 5 and 6, while it was significant when 1 or 2 was used as the substrate. The results suggested high potentials of N. simplex VKM Ac-2033D for the generation of novel 1(2)-dehydroanalogs.

  12. Improvement of biomass properties by pretreatment with ionic liquids for bioconversion process.

    Science.gov (United States)

    Weerachanchai, Piyarat; Leong, Susanna Su Jan; Chang, Matthew Wook; Ching, Chi Bun; Lee, Jong-Min

    2012-05-01

    Cassava pulp residue and rice straw were used as a precursor for pretreatment with ionic liquids to study the effects of pretreatment conditions on product yield and properties. Cassava pulp residue is a potential biomass in the bioconversion process due to it requiring mild pretreatment conditions while providing a high sugar conversion. The maximum sugar conversion and lignin extraction are attained from pretreatment of biomasses with particle size of 1-Ethyl-3-methylimidazolium acetate at 120°C for 24h. The effectiveness of ionic liquid for biomass pretreatment process follows the sequence: 1-Ethyl-3-methylimidazolium acetate>1-Ethyl-3-methylimidazolium diethyl phosphate>1,3-Dimethylimidazolium methyl sulfate. The increase of pretreatment temperature from 25 to 120°C and decrease of biomass particle size renders higher sugar conversion, lignin extraction and lower crystallinity index. However, pretreatment at temperatures higher than 120°C shows a sharp decline of regenerated biomass yield, sugar conversion and lignin extraction and giving higher crystallinity index at pretreatment temperature of 180°C.

  13. Bioconversion of herbal industry waste into vermicompost using an epigeic earthworm Eudrilus eugeniae.

    Science.gov (United States)

    Kumari, Mamta; Kumar, Sudhir; Chauhan, Rajinder Singh; Ravikanth, K

    2011-11-01

    The aim of the present study was to investigate the potential of bioconversion of industrial herbal waste to vermicompost using Eudrilus eugeniae. Vermibeds were made using a mixture of herbal waste and cowdung (1 : 1) in comparison with the use of cowdung alone as substrate, resulting in vermicomposts 1 and 2, respectively. Different parameters were studied and it was observed that the nutrient profile of vermicompost 1 strongly influenced the growth of pea (Pisum sativum) and marigold plant (Tagetus erectus). The dry and fresh weight of shoots and roots, number of flowers, total yield in terms of fruit showed significant increase with vermicompost 1. Furthermore, vermicompost 1 (herbal waste and cow dung as substrate) resulted in a significant reduction in TOC by 58% in comparison with vermicompost 2 (cowdung as substrate). The C : N ratio was less than 20 in vermicompost 1 as well as in vermicompost 2, which indicated an advanced degree of stabilization and mineralization. The ability of earthworms to survive, grow and breed in the vermibed fed with the herbal waste indicates the sustainability and efficiency of a heterogeneous kind of organic waste. The results of the study suggested that bulk industrial herbal waste can be utilized as a substrate for vermicomposting and this can be proposed as an alternative for waste disposal in a clean green manner, promoting the concept of organic farming.

  14. Elimination of sulphur odours at landfills by bioconversion and the corona discharge plasma technique.

    Science.gov (United States)

    Xia, Fangfang; Liu, Xin; Kang, Ying; He, Ruo; Wu, Zucheng

    2015-01-01

    Hydrogen sulphide (H2S) contributes a lot to odours at landfills, which is a threat to the environment and the health of the staff therein. To mitigate its emission, the bioconversion within landfill cover soils (LCSs) was introduced. H2S emission and concentration both in the field air above the landfill and in microcosm testing were surveyed. Results indicated that H2S emission and concentration in the landfill varied with landfill seasons and sites. There existed relationship between H2S concentration and fluxes spatially and temporally. To characterize and assess the spatial and temporal diversity of sulphur-oxidizing bacteria (SOB) and sulphate-reducing bacteria (SRB) in the LCSs, the terminal-restriction fragment length polymorphism technique was employed. Using the functional genes of dsrB and soxB, SOB, including Halothiobacillus, Rhodothalassium, Paracocccus, Allochromatium, and Thiobacillus, and SRB, including Desulfovibrio, Syntrophobacter, Desulfomonile and Desulfobacca, were identical and exhibited the dominant role in the LCSs. By employing an alternative available corona reactor, more than 90% removal efficiencies of sulphides were demonstrated, suggesting that the LCSs for eliminating odours in a lower concentration would be feasible.

  15. A novel bioconversion for value-added products from food waste using Musca domestica.

    Science.gov (United States)

    Niu, Yi; Zheng, Dong; Yao, Binghua; Cai, Zizhe; Zhao, Zhimin; Wu, Shengqing; Cong, Peiqing; Yang, Depo

    2017-03-01

    Food waste, as a major part of the municipal solid waste has been generated increasingly worldwide. Efficient and feasible utilization of this waste material for productivity process is significant for both economical and environmental reasons. In the present study, Musca domestica larva was used as the carrier to conduct a bioconversion with food waste to get the value-added maggot protein, oil and organic fertilizers. Methods of adult flies rearing, culture medium adjuvant selection, maggot culture conditions, stocking density and the valorization of the waste have been explored. From the experimental results, every 1000g culture mediums (700g food waste and 300g adjuvant) could be disposed by 1.5g M. domestica eggs under proper culture conditions after emergence in just 4days, 42.95±0.25% of which had been consumed and the culture medium residues could be used as good organic fertilizers, accompanying with the food waste consumption, ∼53.08g dried maggots that contained 57.06±2.19% protein and 15.07±2.03% oil had been produced. The maggot protein for its outstanding pharmacological activities is regarded as a good raw material in the field of medicine and animal feeding. Meanwhile, the maggot oil represents a potential alternative feedstock for biodiesel production. In our study, the maggot biodiesel was obtained after the procedure of transesterification reaction with methanol and the productivity was 87.71%.

  16. Physico-chemical Profile and Microbial Diversity During Bioconversion of Sugarcane Press Mud Using Bacterial Suspension

    Directory of Open Access Journals (Sweden)

    Tushar Chandra SARKER

    2013-08-01

    Full Text Available This study was aimed at investigating the physico-chemical and microbial diversity for rapid composting of sugarcane press mud (PM leading to organic manure. Five bacterial strains (Cellulomonas sp., Klebsiella sp., Proteus sp., Enterobacter sp., Salmonella sp. were tested under in vivo conditions for bioconversion of PM using pile method. Results revealed that combined inoculation of bacterial consortia was found to be the best decomposer of PM resulting reduction of organic carbon content (26.75%, C:N ratio (12.44%. In parallel, it increased the nitrogen (2.34%, phosphorous (1.15% and potassium (1.37% content along with the population of microorganisms i.e. bacteria, fungi and actinomycetes. However, the population of tested bacteria was gradually depleted after completion of PM decomposition together with pathogenic bacteria and fungi due to full conversion of carbon component into other minerals, i.e. N, P, K etc. Taken together, these findings certainly pinpoints the effective role of bacterial suspension for composting sugarcane press mud which the eventually be used as organic manure.

  17. Bioconversion of Carotenoids in Five Fruits and Vegetables to Vitamin A Measured by Retinol Accumulation in Rat Livers

    Directory of Open Access Journals (Sweden)

    Armando Carrillo-Lopez

    2010-01-01

    Full Text Available Problem statement: Vitamin A deficiency is one of the most prevalent and major nutritional problems in developing countries, especially in young children. In many countries, a substantial proportion of dietary vitamin A is commonly derived from pro-vitamin A carotenoids obtained from colored fruits and orange or green vegetables. However, the bioavailability of retinol derived from carotenoids from these plant sources is not well known. Approach: The present study analyzed β-Carotene and Total Carotenoids (TC composition of carrots (Daucus carota, parsley (Petroselinum crispum, Spinach (Spinacea oleracea, mangoes (Mangifera indica and papayas (Carica papaya and determined the bioconversion of their carotenoids to vitamin A by monitoring the levels of retinol accumulated in liver and plasma of Wistar rats (Rattus norvegicus. Products were freeze-dried, β-Carotene content analyzed by HPLC and TC by Spectrophotometry. Results: Carrots presented the highest content of β-carotene followed by parsley with 32.8 and 19.6 mg 100 g-1, respectively. Spinach had the highest content of TC followed by parsley with 60.7 and 56.7 mg 100 g-1, respectively. Four-week-old male Wistar rats received a standard diet as an adaptation period, a diet free of Carotenoids and Vitamin A (CVA-diet as depletion period and finally a Fruit or Vegetable (FoV based diet as repletion period. The highest β-carotene bioconversion was for mango and the lowest for parsley, whereas the highest TC bioconversion was for carrots and the lowest for parsley. There were no significant differences in plasma retinol between treatments. Conclusion/Recommendations: There was no relation between carotenoids content in FoV-based diet and retinol status in plasma. Furthermore, the employment of a general retinol conversion factor is regarded as not appropriate. So, it is recommended to consider specific conversion factors for groups of horticultural crops, for example, a factor for green leafy

  18. Bioconversion of C-6 sulfidopeptide leukotrienes by the responding guinea pig ileum determines the time course of its contraction.

    Science.gov (United States)

    Krilis, S; Lewis, R A; Corey, E J; Austen, K F

    1983-04-01

    The naturally occurring sulfidopeptide leukotrienes, leukotriene (LT) C(4) (LTC(4)) [5(S)-hydroxy - 6(R) - S - glutathionyl - 7,9 - trans, 11,14 - cis - eicosatetraenoic acid] and its cysteinylglycine (LTD(4)) and cysteinyl (LTE(4)) analogs, which are derived by peptide cleavage, differ in the concentrations required to elicit comparable contractions of the guinea pig ileum, with respective potencies of 1.2:5:1. The effect of the ongoing bioconversion of LTC(4) and LTD(4) on the contractile response of the guinea pig ileum to each was determined by recording the pattern of the contraction and quantitating the initial agonist and its metabolic products. The contraction was elicited by radiolabeled agonist, and its conversion products were sampled at defined intervals and resolved by their retention times on reverse-phase high performance liquid chromatography. After a latent period of 60 s. LTC(4) initiated a linear response, followed by a slower, progressive response to a maximum level that was maintained without relaxation. The metabolic conversion of LTC(4) was contraction and complete inhibition of bioconversion of LTC(4) to LTD(4) by the presence of serine-borate complex did not alter the pattern of the spasmogenic response. As the maximum response in the presence of serine-borate complex was three-quarters of that obtained without the inhibitor of bioconversion, the predominant response was to LTC(4) itself. The spasmogenic response of the ileum to LTD(4) was immediate, linear to a maximum level, and immediately followed by a marked relaxation. That the failure of LTD(4) to sustain a contraction was due to its immediate, rapid, and quantitative conversion to the less potent LTE(4) was established by pharmacologically inhibiting and anatomically deleting the converting activity. In the presence of L-cysteine the conversion of LTD(4) to LTE(4) was largely inhibited and the maximum contractile response was well maintained. After anatomic removal of the mucosa

  19. Bioconversion of C-6 Sulfidopeptide Leukotrienes by the Responding Guinea Pig Ileum Determines the Time Course of its Contraction

    OpenAIRE

    Krilis, Steven; Robert A Lewis; Corey, E J; Austen, K. Frank

    1983-01-01

    The naturally occurring sulfidopeptide leukotrienes, leukotriene (LT) C4 (LTC4) [5(S)-hydroxy - 6(R) - S - glutathionyl - 7,9 - trans, 11,14 - cis - eicosatetraenoic acid] and its cysteinylglycine (LTD4) and cysteinyl (LTE4) analogs, which are derived by peptide cleavage, differ in the concentrations required to elicit comparable contractions of the guinea pig ileum, with respective potencies of 1.2:5:1. The effect of the ongoing bioconversion of LTC4 and LTD4 on the contractile response of t...

  20. Bioconversion of low quality lignocellulosic agricultural waste into edible protein by Pleurotus sajor-caju (Fr.) Singer

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Pleurotus sajor-caju (Fr.) Singer was cultivated on selected agro wastes viz. cotton stalks, groundnut haulms, soybean straw, pigeon pea stalks and leaves and wheat straw, alone or in combinations. Cotton stalks, pigeon pea stalks and wheat straw alone or in combination were found to be more suitable than groundnut haulms and soybean straw for the cultivation. Organic supplements such as groundnut oilseed cake, gram powder and rice bran not only affected growth parameters but also increased yields. Thus bioconversion of lignocellulosie biomass by P. sajor-caju offers a promising way to convert low quality biomass into an improved human food.

  1. Large scale solubilization of coal and bioconversion to utilizable energy. Quarterly report, October 1--December 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, N.C.

    1996-12-22

    In order to develop a system for a large scale coal solubilization and its bioconversion to utilizable fuel, the author plans to clone the genes encoding Neurospora protein that facilitate depolymerization of coal. He also plans to use desulfurizing bacteria to remove the sulfur in situ and use other microorganisms to convert biosolubilized coal into utilizable energy following an approach utilizing several microorganisms. In addition the product of coal solubilized by fungus will be characterized to determine their chemical nature and the mechanism of reaction catalyzed by fungal product during in vivo and in vitro solubilization by the fungus or purified fungal protein.

  2. Large scale solubilization of coal and bioconversion to utilizable energy. Fifth quarterly technical report, January 1, 1995--March 31, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, N.C.

    1995-12-01

    In order to develop a system for a large scale coal solubilization and its bioconversion to utilizable fuel, we plan to clone the genes encoding Neurospora protein that facilitate depolymerization of coal. We also plan to use desulfurizing bacteria to remove the sulfur in situ and use other microorganisms to convert biosolubilized coal into utilizable energy following an approach utilizing several microorganisms. In addition the product of coal solubilized by fungus will be characterized to determine their chemical nature and the mechanism of reaction catalyzed by fungal product during in vivo and in vitro solubilization by the fungus or purified fungal protein.

  3. Two-phase bioconversion product recovery by microfiltration I. Steady state studies.

    Science.gov (United States)

    Conrad, P B; Lee, S S

    1998-03-20

    Recovery of an aqueous bioconversion product from complex, two-phase Pseudomonas putida broths containing 20% (v/v) soybean oil presents a significant challenge for downstream processing. Although not used before in multiple-phase separation for complex biotech products, crossflow filtration employing ceramic filters is one of the most attractive options which allow the design of integrated, continuous bioconversion processes. As a first attempt, we studied multichannel, monolithic ceramic membranes of different nominal pore sizes and lumen diameters under steady-state conditions. The best performance was obtained with 0.2-microm-pore/3-mm-lumen membrane, which completely rejected both cells and oil droplets from the permeate, creating a clear aqueous product stream. Although the same separation was achieved, the 50K molecular weight cut-off (MWCO) ultrafilter showed greater irreversible but similar reversible resistance, in addition to an order-of-magnitude higher membrane resistance. Larger nominal pore microfilters, such as 0.45 and 1.0 microm, experienced both cell and oil leakage even at low transmembrane pressure (10 psig). Attributed to greater shear at the same recirculation rate, smaller lumen filters did provide greater permeate flux. However, for practical purposes, the 0. 2-microm-pore/4-mm-lumen ceramic membrane was chosen for further evaluation. Transmembrane pressures up to 50 psig provided only marginal gains in filtration performance, whereas increasing shear rate resulted in linear increases in steady-state flux, presumably due to formation of shear-sensitive, complex gel/oil/cell layer near the membrane surface. A nominal shear rate of 9200 s-1 and 20 psig transmembrane pressure were chosen as optimal operating conditions. Additional studies in a clean system revealed that as low as 5% (v/v) soybean oil in deionized (DI) water resulted in an order-of-magnitude decline in steady-state permeate flux. Breakthrough of oil droplets occurred at 35 psig

  4. The prospects of cellulase-producing bacteria for the bioconversion of lignocellulosic biomass

    Directory of Open Access Journals (Sweden)

    Miranda Maki, Kam Tin Leung, Wensheng Qin

    2009-01-01

    Full Text Available Lignocellulosic biomass is a renewable and abundant resource with great potential for bioconversion to value-added bioproducts. However, the biorefining process remains economically unfeasible due to a lack of biocatalysts that can overcome costly hurdles such as cooling from high temperature, pumping of oxygen/stirring, and, neutralization from acidic or basic pH. The extreme environmental resistance of bacteria permits screening and isolation of novel cellulases to help overcome these challenges. Rapid, efficient cellulase screening techniques, using cellulase assays and metagenomic libraries, are a must. Rare cellulases with activities on soluble and crystalline cellulose have been isolated from strains of Paenibacillus and Bacillus and shown to have high thermostability and/or activity over a wide pH spectrum. While novel cellulases from strains like Cellulomonas flavigena and Terendinibacter turnerae, produce multifunctional cellulases with broader substrate utilization. These enzymes offer a framework for enhancement of cellulases including: specific activity, thermalstability, or end-product inhibition. In addition, anaerobic bacteria like the clostridia offer potential due to species capable of producing compound multienzyme complexes called cellulosomes. Cellulosomes provide synergy and close proximity of enzymes to substrate, increasing activity towards crystalline cellulose. This has lead to the construction of designer cellulosomes enhanced for specific substrate activity. Furthermore, cellulosome-producing Clostridium thermocellum and its ability to ferment sugars to ethanol; its amenability to co-culture and, recent advances in genetic engineering, offer a promising future in biofuels. The exploitation of bacteria in the search for improved enzymes or strategies provides a means to upgrade feasibility for lignocellulosic biomass conversion, ultimately providing means to a 'greener' technology.

  5. Bio-hydrogen production by biodiesel-derived crude glycerol bioconversion: a techno-economic evaluation.

    Science.gov (United States)

    Sarma, Saurabh Jyoti; Brar, Satinder Kaur; Le Bihan, Yann; Buelna, Gerardo

    2013-01-01

    Global biodiesel production is continuously increasing and it is proportionally accompanied by a huge amount of crude glycerol (CG) as by-product. Due to its crude nature, CG has very less commercial interest; although its pure counterpart has different industrial applications. Alternatively, CG is a very good carbon source and can be used as a feedstock for fermentative hydrogen production. Further, a move of this kind has dual benefits, namely it offers a sustainable method for disposal of biodiesel manufacturing waste as well as produces biofuels and contributes in greenhouse gas (GHG) reduction. Two-stage fermentation, comprising dark and photo-fermentation is one of the most promising options available for bio-hydrogen production. In the present study, techno-economic feasibility of such a two-stage process has been evaluated. The analysis has been made based on the recent advances in fermentative hydrogen production using CG as a feedstock. The study has been carried out with special reference to North American biodiesel market; and more specifically, data available for Canadian province, Québec City have been used. Based on our techno-economic analysis, higher production cost was found to be the major bottleneck in commercial production of fermentative hydrogen. However, certain achievable alternative options for reduction of process cost have been identified. Further, the process was found to be capable in reducing GHG emissions. Bioconversion of 1 kg of crude glycerol (70 % w/v) was found to reduce 7.66 kg CO(2) eq (equivalent) GHG emission, and the process also offers additional environmental benefits.

  6. Mycelial cultivation of Phellinus linteus using cheese-processing waste and optimization of bioconversion conditions.

    Science.gov (United States)

    Lee, Changsoo; Lee, Seungyong; Cho, Kyung-Jin; Hwang, Seokhwan

    2011-02-01

    A medicinal mushroom, Phellinus linteus, was successfully cultivated using a cheese-processing waste, whey, and the optimal bioconversion conditions for the maximum mycelial growth rate was also estimated through solid-state cultivation experiments. Response surface analysis with a face-centered design (center point replication = 5) was applied to statistically approximate the simultaneous effects of the three variables, i.e., substrate concentration (10-30 g lactose l⁻¹), temperature (20-30°C), and pH (4-6), on the mycelial growth rate of P. linteus. The following is a partial cubic model where η is the mycelial growth rate (K(r)) and x(k) is the corresponding variable term (k = substrate concentration, temperature, and pH in order): η = -23.8 + 8.67 × 10⁻² x₁ + 1.48x₂ + 1.77x₃ + 8.00 × 10⁻⁴ x₁x₂ + 7.25 × 10⁻² x₁x₃ + 5.13 × 10⁻² x₂x₃ -1.28 × 10⁻² x₁² -3.18 × 10⁻² x²₂. -2.64 × 10⁻¹ x₃² -3.28 × 10⁻³ x₁x₂ x₃ + 4.68 × 10⁻⁴ x₁²x₂. The produced response surface model proved to be significant (r² > 0.99, P-value linteus mycelia. This may provide another potential for managing this nutrient-rich waste in a cost-effective way.

  7. Bioconversion of sugarcane biomass into ethanol: an overview about composition, pretreatment methods, detoxification of hydrolysates, enzymatic saccharification, and ethanol fermentation.

    Science.gov (United States)

    Canilha, Larissa; Kumar Chandel, Anuj; dos Santos Milessi, Thais Suzane; Fernandes Antunes, Felipe Antônio; da Costa Freitas, Wagner Luiz; das Graças Almeida Felipe, Maria; da Silva, Silvio Silvério

    2012-01-01

    Depleted supplies of fossil fuel, regular price hikes of gasoline, and environmental damage have necessitated the search for economic and eco-benign alternative of gasoline. Ethanol is produced from food/feed-based substrates (grains, sugars, and molasses), and its application as an energy source does not seem fit for long term due to the increasing fuel, food, feed, and other needs. These concerns have enforced to explore the alternative means of cost competitive and sustainable supply of biofuel. Sugarcane residues, sugarcane bagasse (SB), and straw (SS) could be the ideal feedstock for the second-generation (2G) ethanol production. These raw materials are rich in carbohydrates and renewable and do not compete with food/feed demands. However, the efficient bioconversion of SB/SS (efficient pretreatment technology, depolymerization of cellulose, and fermentation of released sugars) remains challenging to commercialize the cellulosic ethanol. Among the technological challenges, robust pretreatment and development of efficient bioconversion process (implicating suitable ethanol producing strains converting pentose and hexose sugars) have a key role to play. This paper aims to review the compositional profile of SB and SS, pretreatment methods of cane biomass, detoxification methods for the purification of hydrolysates, enzymatic hydrolysis, and the fermentation of released sugars for ethanol production.

  8. High-yield enzymatic bioconversion of hydroquinone to α-arbutin, a powerful skin lightening agent, by amylosucrase.

    Science.gov (United States)

    Seo, Dong-Ho; Jung, Jong-Hyun; Ha, Suk-Jin; Cho, Hyun-Kug; Jung, Dong-Hyun; Kim, Tae-Jip; Baek, Nam-In; Yoo, Sang-Ho; Park, Cheon-Seok

    2012-06-01

    α-Arbutin (α-Ab) is a powerful skin whitening agent that blocks epidermal melanin biosynthesis by inhibiting the enzymatic oxidation of tyrosine and L-3,4-dihydroxyphenylalanine (L-DOPA). α-Ab was effectively synthesized from hydroquinone (HQ) by enzymatic biotransformation using amylosucrase (ASase). The ASase gene from Deinococcus geothermalis (DGAS) was expressed and efficiently purified from Escherichia coli using a constitutive expression system. The expressed DGAS was functional and performed a glycosyltransferase reaction using sucrose as a donor and HQ as an acceptor. The presence of a single HQ bioconversion product was confirmed by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). The HQ bioconversion product was isolated by silica gel open column chromatography and its chemical structure determined by 1H and 13C nuclear magnetic resonance (NMR). The product was determined to be hydroquinone-O-α-D-glucopyranoside with a glucose molecule linked to HQ through an α-glycosidic bond. However, the production yield of the transfer reaction was significantly low (1.3%) due to the instability of HQ in the reaction mixture. The instability of HQ was considerably improved by antioxidant agents, particularly ascorbic acid, implying that HQ is labile to oxidation. A maximum yield of HQ transfer product of 90% was obtained at a 10:1 molar ratio of donor (sucrose) and acceptor (HQ) molecules in the presence of 0.2 mM ascorbic acid.

  9. Bioconversion of Sugarcane Biomass into Ethanol: An Overview about Composition, Pretreatment Methods, Detoxification of Hydrolysates, Enzymatic Saccharification, and Ethanol Fermentation

    Directory of Open Access Journals (Sweden)

    Larissa Canilha

    2012-01-01

    Full Text Available Depleted supplies of fossil fuel, regular price hikes of gasoline, and environmental damage have necessitated the search for economic and eco-benign alternative of gasoline. Ethanol is produced from food/feed-based substrates (grains, sugars, and molasses, and its application as an energy source does not seem fit for long term due to the increasing fuel, food, feed, and other needs. These concerns have enforced to explore the alternative means of cost competitive and sustainable supply of biofuel. Sugarcane residues, sugarcane bagasse (SB, and straw (SS could be the ideal feedstock for the second-generation (2G ethanol production. These raw materials are rich in carbohydrates and renewable and do not compete with food/feed demands. However, the efficient bioconversion of SB/SS (efficient pretreatment technology, depolymerization of cellulose, and fermentation of released sugars remains challenging to commercialize the cellulosic ethanol. Among the technological challenges, robust pretreatment and development of efficient bioconversion process (implicating suitable ethanol producing strains converting pentose and hexose sugars have a key role to play. This paper aims to review the compositional profile of SB and SS, pretreatment methods of cane biomass, detoxification methods for the purification of hydrolysates, enzymatic hydrolysis, and the fermentation of released sugars for ethanol production.

  10. Recombinant Saccharomyces cerevisiae strain expressing a model cytochrome P450 in the rat digestive environment: viability and bioconversion activity.

    Science.gov (United States)

    Garrait, G; Jarrige, J F; Blanquet, S; Beyssac, E; Alric, M

    2007-06-01

    An innovative "biodrug" concept, based on the oral administration of living recombinant microorganisms, has recently emerged for the prevention or treatment of various diseases. An engineered Saccharomyces cerevisiae strain expressing plant P450 73A1 (cinnamate-4-hydroxylase [CA4H] activity) was used, and its survival and ability to convert trans-cinnamic acid (CIN) into p-coumaric acid (COU) were investigated in vivo. In rats, the recombinant yeast was resistant to gastric and small intestinal secretions but was more sensitive to the conditions found in the large intestine. After oral administration of yeast and CIN, the CA4H activity was shown in vivo, with COU being found throughout the rat's digestive tract and in its urine. The bioconversion reaction occurred very fast, with most of the COU being produced within the first 5 min. The gastrointestinal sac technique demonstrated that the recombinant yeast was able to convert CIN into COU (conversion rate ranging from 2 to 5%) in all the organs of the rat's digestive tract: stomach, duodenum, jejunum, ileum, cecum, and colon. These results promise new opportunities for the development of drug delivery systems based on engineered yeasts catalyzing a bioconversion reaction directly in the digestive tract.

  11. Production of itaconate by whole-cell bioconversion of citrate mediated by expression of multiple cis-aconitate decarboxylase (cadA) genes in Escherichia coli

    Science.gov (United States)

    Kim, Junyoung; Seo, Hyung-Min; Bhatia, Shashi Kant; Song, Hun-Seok; Kim, Jung-Ho; Jeon, Jong-Min; Choi, Kwon-Young; Kim, Wooseong; Yoon, Jeong-Jun; Kim, Yun-Gon; Yang, Yung-Hun

    2017-01-01

    Itaconate, a C5 unsaturated dicarboxylic acid, is an important chemical building block that is used in manufacturing high-value products, such as latex and superabsorbent polymers. Itaconate is produced by fermentation of sugars by the filamentous fungus Aspergillus terreus. However, fermentation by A. terreus involves a long fermentation period and the formation of various byproducts, resulting in high production costs. E. coli has been developed as an alternative for producing itaconate. However, fermentation of glucose gives low conversion yields and low productivity. Here, we report the whole-cell bioconversion of citrate to itaconate with enhanced aconitase and cis-aconitate decarboxylase activities by controlling the expression of multiple cadA genes. In addition, this bioconversion system does not require the use of buffers, which reduces the production cost and the byproducts released during purification. Using this whole-cell bioconversion system, we were able to catalyze the conversion of 319.8 mM of itaconate (41.6 g/L) from 500 mM citrate without any buffer system or additional cofactors, with 64.0% conversion in 19 h and a productivity of 2.19 g/L/h. Our bioconversion system suggests very high productivity for itaconate production. PMID:28051098

  12. Improving the bioconversion yield of carbohydrates and ethanol from lignocellulosic biomass

    Science.gov (United States)

    Ewanick, Shannon M.

    Improving the efficiency of lignocellulosic ethanol production is of the utmost importance if cellulosic bioethanol is to be competitive with fossil fuels and first generation bioethanol from starch and sucrose. Improvements in individual processes (pretreatment, saccharification, fermentation) have been ongoing, but few researchers have considered the effect that the incoming raw biomass can have on the process. It is important to understand how biomass can be altered to provide the maximum yield of hydrolysable and fermentable sugars from whatever is available. Since the moisture content is highly variable and easily altered, the effect of drying and rewetting on bioconversion was studied on switchgrass, sugarcane bagasse and hybrid poplar. For switchgrass and sugarcane bagasse, the ethanol yield after simultaneous saccharification and fermentation was improved 18-24% by increasing the moisture content by soaking prior to pretreatment. It was also found that soaking had no effect when the samples were not catalyzed with SO2 confirming that the effect of moisture content is directly related to SO2 uptake and diffusion into the biomass. In hybrid poplar, the results were similar to herbaceous biomass for chips with less than 2% absorbed SO2. However, when the SO2 uptake was increased to 3% even the air dried chips exhibited high digestibility, indicating that increased SO2 uptake can overcome the poor diffusion in dried biomass. Alongside controlling the biomass moisture content, improving knowledge and control of the processes can also increase efficiency and product yields. By monitoring reactions continuously with accurate, robust, on-line sensors, operators can detect when reactions deviate from the norm, and when they are complete. Avoiding process upsets and contamination could be the difference between an economically viable biorefinery and one that struggles to compete. Real time, continuous Raman spectroscopy was used to continuously monitor both a

  13. Bioconversion of kraft paper mill sludges to ethanol by SSF and SSCF.

    Science.gov (United States)

    Kang, Li; Wang, Wei; Lee, Yoon Y

    2010-05-01

    Paper mill sludge is a solid waste material composed of pulp residues and ash generated from pulping and paper making processes. The carbohydrate portion of the sludge has chemical and physical characteristics similar to pulp. Because of its high carbohydrate content and well-dispersed structure, the sludges can be biologically converted to value-added products without pretreatment. In this study, two different types of paper mill sludges, primary sludge and recycle sludge, were evaluated as a feedstock for bioconversion to ethanol. The sludges were first subjected to enzymatic conversion to sugars by commercial cellulase enzymes. The enzymatic conversion was inefficient because of interference by ash in the sludges with the enzymatic reaction. The main cause was that the pH level is dictated by CaCO3 in ash, which is two units higher than the pH optimum of cellulase. To alleviate this problem, simultaneous saccharification and cofermentation (SSCF) using cellulase (Spezyme CP) and recombinant Escherichia coli (ATCC-55124), and simultaneous saccharification and fermentation (SSF) using cellulase and Saccharomyces cerevisiae (ATCC-200062) were applied to the sludges without any pretreatment. Ethanol yields of 75-81% of the theoretical maximum were obtained from the SSCF on the basis of total carbohydrates. The yield from the SSF was also found to be in the range of 74-80% on the basis of glucan. The SSCF and SSF proceeded under stable condition with the pH staying near 5.0, close to the optimum for cellulase. Decrease of pH occurred due to carbonic acid and other organic acids formed during fermentation. The ash was partially neutralized by the acids produced from the SSCF and SSF and acted as a buffer to stabilize the pH during fermentation. When the SSF and SSCF were operated in fed-batch mode, the ethanol concentration in the broth increased from 25.5 and 32.6 g/L (single feed) to 45 and 42 g/L, respectively. The ethanol concentration was limited by the tolerance

  14. Development of Thermophilic Tailor-Made Enzyme Mixtures for the Bioconversion of Agricultural and Forest Residues.

    Science.gov (United States)

    Karnaouri, Anthi; Matsakas, Leonidas; Topakas, Evangelos; Rova, Ulrika; Christakopoulos, Paul

    2016-01-01

    Even though the main components of all lignocellulosic feedstocks include cellulose, hemicellulose, as well as the protective lignin matrix, there are some differences in structure, such as in hardwoods and softwoods, which may influence the degradability of the materials. Under this view, various types of biomass might require a minimal set of enzymes that has to be tailor-made. Partially defined complex mixtures that are currently commercially used are not adapted to efficiently degrade different materials, so novel enzyme mixtures have to be customized. Development of these cocktails requires better knowledge about the specific activities involved, in order to optimize hydrolysis. The role of filamentous fungus Myceliophthora thermophila and its complete enzymatic repertoire for the bioconversion of complex carbohydrates has been widely proven. In this study, four core cellulases (MtCBH7, MtCBH6, MtEG5, and MtEG7), in the presence of other four "accessory" enzymes (mannanase, lytic polyssacharide monooxygenase MtGH61, xylanase, MtFae1a) and β-glucosidase MtBGL3, were tested as a nine-component cocktail against one model substrate (phosphoric acid swollen cellulose) and four hydrothermally pretreated natural substrates (wheat straw as an agricultural waste, birch, and spruce biomass, as forest residues). Synergistic interactions among different enzymes were determined using a suitable design of experiments methodology. The results suggest that for the hydrolysis of the pure substrate (PASC), high proportions of MtEG7 are needed for efficient yields. MtCBH7 and MtEG7 are enzymes of major importance during the hydrolysis of pretreated wheat straw, while MtCBH7 plays a crucial role in case of spruce. Cellobiohydrolases MtCBH6 and MtCBH7 act in combination and are key enzymes for the hydrolysis of the hardwood (birch). Optimum combinations were predicted from suitable statistical models which were able to further increase hydrolysis yields, suggesting that tailor

  15. Evaluation of the bioconversion of genetically modified switchgrass using simultaneous saccharification and fermentation and a consolidated bioprocessing approach

    Directory of Open Access Journals (Sweden)

    Yee Kelsey L

    2012-11-01

    Full Text Available Abstract Background The inherent recalcitrance of lignocellulosic biomass is one of the major economic hurdles for the production of fuels and chemicals from biomass. Additionally, lignin is recognized as having a negative impact on enzymatic hydrolysis of biomass, and as a result much interest has been placed on modifying the lignin pathway to improve bioconversion of lignocellulosic feedstocks. Results Down-regulation of the caffeic acid 3-O-methyltransferase (COMT gene in the lignin pathway yielded switchgrass (Panicum virgatum that was more susceptible to bioconversion after dilute acid pretreatment. Here we examined the response of these plant lines to milder pretreatment conditions with yeast-based simultaneous saccharification and fermentation and a consolidated bioprocessing approach using Clostridium thermocellum, Caldicellulosiruptor bescii and Caldicellulosiruptor obsidiansis. Unlike the S. cerevisiae SSF conversions, fermentations of pretreated transgenic switchgrass with C. thermocellum showed an apparent inhibition of fermentation not observed in the wild-type switchgrass. This inhibition can be eliminated by hot water extraction of the pretreated biomass, which resulted in superior conversion yield with transgenic versus wild-type switchgrass for C. thermocellum, exceeding the yeast-based SSF yield. Further fermentation evaluation of the transgenic switchgrass indicated differential inhibition for the Caldicellulosiruptor sp. strains, which could not be rectified by additional processing conditions. Gas chromatography–mass spectrometry (GC-MS metabolite profiling was used to examine the fermentation broth to elucidate the relative abundance of lignin derived aromatic compounds. The types and abundance of fermentation-derived-lignin constituents varied between C. thermocellum and each of the Caldicellulosiruptor sp. strains. Conclusions The down-regulation of the COMT gene improves the bioconversion of switchgrass relative to the

  16. evaluation of the bioconversion of genetically modified switchgrass using simultaneous saccharification and fermentation ans a consolidated bioprocessing approach

    Energy Technology Data Exchange (ETDEWEB)

    Yee, Kelsey L [ORNL; Rodriguez, Jr., Miguel [ORNL; Tschaplinski, Timothy J [ORNL; Engle, Nancy L [ORNL; Martin, Madhavi Z [ORNL; Fu, Chunxiang [Noble Foundation; Wang, Zeng-Yu [Noble Foundation; Hamilton-Brehm, Scott [ORNL; Mielenz, Jonathan R [ORNL

    2012-01-01

    Abstract Background: The inherent recalcitrance of lignocellulosic biomass is one of the major economic hurdles for the production of fuels and chemicals from biomass. Additionally, lignin is recognized as having a negative impact on enzymatic hydrolysis of biomass, and as a result much interest has been placed on modifying the lignin pathway to improve bioconversion of lignocellulosic feedstocks. Results: Previous results showed down-regulation of the caffeic acid 3-O-methyl transferase (COMT) gene in the lignin pathway yielded switchgrass (Panicum virgatum) that was more susceptible to bioconversion after dilute acid pretreatment. Here we examined the response of these plant lines to milder pretreatment conditions with yeast-based SSF, CBP with Clostridium thermocellum, and fermentations with the cellulolytic extreme thermophiles, Caldicellulosiruptor bescii and Caldicellulosiruptor obsidiansis. Unlike the S. cerevisiae SSF conversions, fermentations of pretreated down-regulated COMT transgenic switchgrass with C. thermocellum showed an apparent inhibition of fermentation not observed in the wild-type switchgrass. This inhibition can be eliminated by hot water extraction of the pretreated biomass which resulted in superior conversion yield with transgenic versus wild-type switchgrass for C. thermocellum, also exceeding the yeast-based SSF yield. Further fermentation evaluation of the transgenic switchgrass indicated differential inhibition for the Caldicellulosiruptor strains, which could not be rectified by additional processing conditions. Gas chromatography-mass spectrometry metabolite profiling was used to examine the fermentation broth to elucidate the relative abundance of lignin derived aromatic compounds. The types and abundance of fermentation-derived lignin constituents varied between C. thermocellum and each of the Caldicellulosiruptor strains. Conclusions: The down-regulation of the COMT gene improves the bioconversion of switchgrass relative to the

  17. An efficient approach to bioconversion kinetic model generation based on automated microscale experimentation integrated with model driven experimental design

    DEFF Research Database (Denmark)

    Chen, B. H.; Micheletti, M.; Baganz, F.;

    2009-01-01

    design. It incorporates a model driven approach to the experimental design that minimises the number of experiments to be performed, while still generating accurate values of kinetic parameters. The approach has been illustrated with the transketolase mediated asymmetric synthesis of L...... experimental design.]it comparison with conventional methodology, the modelling approach enabled a nearly 4-fold decrease in the number of experiments while the microwell experimentation enabled a 45-fold decrease in material requirements and a significant increase in experimental throughput. The approach......Reliable models of enzyme kinetics are required for the effective design of bioconversion processes. Kinetic expressions of the enzyme-catalysed reaction rate however, are frequently complex and establishing accurate values of kinetic parameters normally requires a large number of experiments...

  18. Large scale solubilization of coal and bioconversion to utilizable energy. Technical progress report, January 1--March 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, N.C.

    1996-05-01

    In order develop a system for a large scale coal solubilization and its bioconversion to utilizable fuel, the authors plan to clone the genes encoding Neurospora protein that facilitates depolymerization of coal. They also plan to use desulfurizing bacteria to remove the sulfur in situ and use other microorganisms to convert biosolubilized coal into utilizable energy following an approach utilizing several microorganisms. In addition the products of coal solubilized by fungus will be characterized to determine their chemical nature and the mechanism of reaction catalyzed by fungal product during in vivo and in vitro solubilization by the fungus or purified fungal protein. Results are presented for the cloning of genes for Neurospora CSA-protein.

  19. Nitrile bioconversion by Microbacterium imperiale CBS 498-74 resting cells in batch and ultrafiltration membrane bioreactors.

    Science.gov (United States)

    Cantarella, M; Cantarella, L; Gallifuoco, A; Spera, A

    2006-03-01

    The biohydration of acrylonitrile, propionitrile and benzonitrile catalysed by the NHase activity contained in resting cells of Microbacterium imperiale CBS 498-74 was operated at 5, 10 and 20 degrees C in laboratory-scale batch and membrane bioreactors. The bioreactions were conducted in buffered medium (50 mM Na(2)HPO(4)/NaH(2)PO(4), pH 7.0) in the presence of distilled water or tap-water, to simulate a possible end-pipe biotreatment process. The integral bioreactor performances were studied with a cell loading (dry cell weight; DCW) varying from 0.1 mg(DCW) per reactor to 16 mg(DCW) per reactor, in order to realize near 100% bioconversion of acrylonitrile, propionitrile and benzonitrile without consistent loss of NHase activity.

  20. Bioconversion of Gibberellin Fermentation Residue into Feed Supplement and Organic Fertilizer Employing Housefly (Musca domestica L. Assisted by Corynebacterium variabile.

    Directory of Open Access Journals (Sweden)

    Sen Yang

    Full Text Available The accumulation of a considerable quantity of gibberellin fermentation residue (GFR during gibberellic acid A3 (GA3 production not only results in the waste of many resources, but also poses a potential hazard to the environment, indicating that the safe treatment of GFR has become an urgent issue for GA3 industry. The key to recycle GFR is converting it into an available resource and removing the GA3 residue. To this end, we established a co-bioconversion process in this study using house fly larvae (HFL and microbes (Corynebacterium variabile to convert GFR into insect biomass and organic fertilizer. About 85.5% GA3 in the GFR was removed under the following optimized solid-state fermentation conditions: 60% GFR, 40% rice straw powder, pH 8.5 and 6 days at 26 °C. A total of 371 g housefly larvae meal and 2,064 g digested residue were bio-converted from 3,500 g raw GFR mixture contaning1, 400 g rice straw in the unit of (calculated dry matter. HFL meal derived from GFR contained 56.4% protein, 21.6% fat, and several essential amino acids, suggesting that it is a potential alternative animal feed protein source. Additionally, the digested GFR could be utilized as an organic fertilizer with a content of 3.2% total nitrogen, 2.0% inorganic phosphorus, 1.3% potassium and 91.5% organic matter. This novel GFR bio-conversion method can mitigate potential environmental pollution and recycle the waste resources.

  1. Bioconversion of Gibberellin Fermentation Residue into Feed Supplement and Organic Fertilizer Employing Housefly (Musca domestica L.) Assisted by Corynebacterium variabile.

    Science.gov (United States)

    Yang, Sen; Xie, Jiufeng; Hu, Nan; Liu, Yixiong; Zhang, Jiner; Ye, Xiaobin; Liu, Ziduo

    2015-01-01

    The accumulation of a considerable quantity of gibberellin fermentation residue (GFR) during gibberellic acid A3 (GA3) production not only results in the waste of many resources, but also poses a potential hazard to the environment, indicating that the safe treatment of GFR has become an urgent issue for GA3 industry. The key to recycle GFR is converting it into an available resource and removing the GA3 residue. To this end, we established a co-bioconversion process in this study using house fly larvae (HFL) and microbes (Corynebacterium variabile) to convert GFR into insect biomass and organic fertilizer. About 85.5% GA3 in the GFR was removed under the following optimized solid-state fermentation conditions: 60% GFR, 40% rice straw powder, pH 8.5 and 6 days at 26 °C. A total of 371 g housefly larvae meal and 2,064 g digested residue were bio-converted from 3,500 g raw GFR mixture contaning1, 400 g rice straw in the unit of (calculated) dry matter. HFL meal derived from GFR contained 56.4% protein, 21.6% fat, and several essential amino acids, suggesting that it is a potential alternative animal feed protein source. Additionally, the digested GFR could be utilized as an organic fertilizer with a content of 3.2% total nitrogen, 2.0% inorganic phosphorus, 1.3% potassium and 91.5% organic matter. This novel GFR bio-conversion method can mitigate potential environmental pollution and recycle the waste resources.

  2. Comparison of γ-irradiation with other pretreatments followed with simultaneous saccharification and fermentation on bioconversion of microcrystalline cellulose for bioethanol production.

    Science.gov (United States)

    Liu, Yun; Zhou, Hua; Wang, Shihui; Wang, Keqin; Su, Xiaojun

    2015-04-01

    The effect of γ-irradiation pretreatment was compared with other pretreatment methods including ionic liquids (ILs), 1% HCl, 1% H2SO4, acidic aqueous Ils (AA-ILs), on the bioconversion efficiency of microcrystalline cellulose (MCC) for bioethanol production. The efficiency of MCC pretreatment followed with simultaneous saccharification and fermentation (SSF) was firstly evaluated according to the variations of the irradiation-derived compounds and structure of MCC, as well as yeast growth curve and bioethanol yield. Results showed that the appropriate irradiation dose (891 kGy used in our work) could eliminate the negative effect of toxic irradiation-derived compounds on SSF for ethanol bioconversion with the yield value of 67%. Analyses of SEM, FT-IR, reducing sugar and bioethanol yield showed that the efficiency of pretreatment on MCC was ILs ≈ irradiation pretreatment > AA-ILs pretreatment > 1% HCl pretreatment > 1% H2SO4 pretreatment.

  3. Research report of fiscal 1997. Survey on creation of high-efficiency renewable resources, and bioconversion technology; 1997 nendo chosa hokokusho. Kokoritsu saisei kano shigen no sosei narabi ni bioconversion gijutsu ni kansuru chosa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    Survey was made on material production technology using creation technology of high-efficiency renewable resources (photosynthesis reaction of plants). Industrially usable plant resources in overseas countries and Japan were arranged, and plant resources unused for food were also surveyed. The present state of genetic engineering necessary for metabolic engineering of higher plants such as fit and high-expression technology of genes, plant cell cultivation, and control technology of plant cell multiplication is described, and elementary technologies required for future gene-recombined plants are predicted. Survey was also made on the trend of creation technology of industrial plants for fat and oil, biodegradable polyester, amino acid, cellulose, fiber (cotton) and forest wood. A patent list on plant biotechnology was prepared, and study on bioconversion of plant resources was also surveyed. Overseas R & D trends on conversion and effective use technologies of renewable bio- resources are reported, and process design and its profitability were evaluated through a case study. 414 refs., 87 figs., 55 tabs.

  4. Bioconversion of coal-derived synthesis gas to liquid fuels. Final technical report, September 1, 1990--August 31, 1991

    Energy Technology Data Exchange (ETDEWEB)

    Jain, M.K.

    1991-12-31

    The use of coal-derived synthesis gas as an industrial feedstock for production of fuels and chemicals has become an increasingly attractive alternative to present petroleum-based chemicals production. However, one of the major limitations in developing such a process is the required removal of catalyst poisons such as hydrogen sulfide (H{sub 2}S), carbonyl sulfide (COS), and other trace contaminants from the synthesis gas. Purification steps necessary to remove these are energy intensive and add significantly to the production cost, particularly for coals having a high sulfur content such as Illinois coal. A two-stage, anaerobic bioconversion process requiring little or no sulfur removal is proposed, where in the first stage the carbon monoxide (CO) gas is converted to butyric and acetic acids by the CO strain of Butyribacterium methylotrophicum. In the second stage, these acids along with the hydrogen (H{sub 2}) gas are converted to butanol, ethanol, and acetone by an acid utilizing mutant of Clostridium acetobutylicum. 18 figs., 18 tabs.

  5. Highly Selective Bioconversion of Ginsenoside Rb1 to Compound K by the Mycelium of Cordyceps sinensis under Optimized Conditions

    Directory of Open Access Journals (Sweden)

    Wei-Nan Wang

    2015-10-01

    Full Text Available Compound K (CK, a highly active and bioavailable derivative obtained from protopanaxadiol ginsenosides, displays a wide variety of pharmacological properties, especially antitumor activity. However, the inadequacy of natural sources limits its application in the pharmaceutical industry. In this study, we firstly discovered that Cordyceps sinensis was a potent biocatalyst for the biotransformation of ginsenoside Rb1 into CK. After a series of investigations on the biotransformation parameters, an optimal composition of the biotransformation culture was found to be lactose, soybean powder and MgSO4 without controlling the pH. Also, an optimum temperature of 30 °C for the biotransformation process was suggested in a range of 25 °C–50 °C. Then, a biotransformation pathway of Rb1 → Rd → F2 → CK was established using high performance liquid chromatography/quadrupole time-of-flight mass spectrometry (HPLC-Q-TOF-MS. Our results demonstrated that the molar bioconversion rate of Rb1 to CK was more than 82% and the purity of CK produced by C. sinensis under the optimized conditions was more than 91%. In conclusion, the combination of C. sinensis and the optimized conditions is applicable for the industrial preparation of CK for medicinal purposes.

  6. Highly Selective Bioconversion of Ginsenoside Rb1 to Compound K by the Mycelium of Cordyceps sinensis under Optimized Conditions.

    Science.gov (United States)

    Wang, Wei-Nan; Yan, Bing-Xiong; Xu, Wen-Di; Qiu, Ye; Guo, Yun-Long; Qiu, Zhi-Dong

    2015-10-23

    Compound K (CK), a highly active and bioavailable derivative obtained from protopanaxadiol ginsenosides, displays a wide variety of pharmacological properties, especially antitumor activity. However, the inadequacy of natural sources limits its application in the pharmaceutical industry. In this study, we firstly discovered that Cordyceps sinensis was a potent biocatalyst for the biotransformation of ginsenoside Rb1 into CK. After a series of investigations on the biotransformation parameters, an optimal composition of the biotransformation culture was found to be lactose, soybean powder and MgSO₄ without controlling the pH. Also, an optimum temperature of 30 °C for the biotransformation process was suggested in a range of 25 °C-50 °C. Then, a biotransformation pathway of Rb1→Rd→F2→CK was established using high performance liquid chromatography/quadrupole time-of-flight mass spectrometry (HPLC-Q-TOF-MS). Our results demonstrated that the molar bioconversion rate of Rb1 to CK was more than 82% and the purity of CK produced by C. sinensis under the optimized conditions was more than 91%. In conclusion, the combination of C. sinensis and the optimized conditions is applicable for the industrial preparation of CK for medicinal purposes.

  7. Optimization of process parameters for the bioconversion of activated sludge by Penicillium corylophilum,using response surface methodology

    Institute of Scientific and Technical Information of China (English)

    Sarkar Mannan; Ahmadun Fakhru'l-Razi; Md Zahangir Alam

    2007-01-01

    The optimization of process parameters for the bioconversion of activated sludge by Penicillium corylophilum was investigated using response surface methodology (RSM). The three parameters namely temperature of 33(C, agitation of 150 r/min, and pH of 5 were chosen as center point from the previous study of fungal treatment. The experimental data on chemical oxygen demand (COD) removal (%) were fitted into a quadratic polynomial model using multiple regression analysis. The optimum process conditions were determined by analyzing response surface three-dimensional surface plot and contour plot and by solving the regression model equation with Design Expert software. Box-Behnken design technique under RSM was used to optimize their interactions, which showed that an incubation temperature of 32.5(C, agitation of 105 r/min, and pH of 5.5 were the best conditions. Under these conditions, the maximum predicted yield of COD removal was 98.43%. These optimum conditions were used to evaluate the trail experiment, and the maximum yield of COD removal was recorded as 98.5%.

  8. Improving Biomethane Production and Mass Bioconversion of Corn Stover Anaerobic Digestion by Adding NaOH Pretreatment and Trace Elements

    Directory of Open Access Journals (Sweden)

    ChunMei Liu

    2015-01-01

    Full Text Available This research applied sodium hydroxide (NaOH pretreatment and trace elements to improve biomethane production when using corn stover for anaerobic digestion. Full-factor experimental tests identified the best combination of trace elements with the NaOH pretreatment, indicating that the best combination was with 1.0, 0.4, and 0.4 mg·L−1·d−1 of elements Fe, Co, and Ni, respectively. The cumulative biomethane production adding NaOH pretreatment and trace elements was 11,367 mL; total solid bioconversion rate was 55.7%, which was 41.8%–62.2% higher than with NaOH-pretreatment alone and 22.2%–56.3% higher than with untreated corn stover. The best combination was obtained 5–9 days shorter than T90 and maintained good system operation stability. Only a fraction of the trace elements in the best combination was present in the resulting solution; more than 85% of the total amounts added were transferred into the solid fraction. Adding 0.897 g of Fe, 0.389 g of Co, and 0.349 g of Ni satisfied anaerobic digestion needs and enhanced biological activity at the beginning of the operation. The results showed that NaOH pretreatment and adding trace elements improve corn stover biodegradability and enhance biomethane production.

  9. Improving Biomethane Production and Mass Bioconversion of Corn Stover Anaerobic Digestion by Adding NaOH Pretreatment and Trace Elements.

    Science.gov (United States)

    Liu, ChunMei; Yuan, HaiRong; Zou, DeXun; Liu, YanPing; Zhu, BaoNing; Li, XiuJin

    2015-01-01

    This research applied sodium hydroxide (NaOH) pretreatment and trace elements to improve biomethane production when using corn stover for anaerobic digestion. Full-factor experimental tests identified the best combination of trace elements with the NaOH pretreatment, indicating that the best combination was with 1.0, 0.4, and 0.4 mg·L(-1)·d(-1) of elements Fe, Co, and Ni, respectively. The cumulative biomethane production adding NaOH pretreatment and trace elements was 11,367 mL; total solid bioconversion rate was 55.7%, which was 41.8%-62.2% higher than with NaOH-pretreatment alone and 22.2%-56.3% higher than with untreated corn stover. The best combination was obtained 5-9 days shorter than T90 and maintained good system operation stability. Only a fraction of the trace elements in the best combination was present in the resulting solution; more than 85% of the total amounts added were transferred into the solid fraction. Adding 0.897 g of Fe, 0.389 g of Co, and 0.349 g of Ni satisfied anaerobic digestion needs and enhanced biological activity at the beginning of the operation. The results showed that NaOH pretreatment and adding trace elements improve corn stover biodegradability and enhance biomethane production.

  10. Assessment of sewage sludge bioremediation at different hydraulic retention times using mixed fungal inoculation by liquid-state bioconversion.

    Science.gov (United States)

    Rahman, Roshanida A; Molla, Abul Hossain; Fakhru'l-Razi, A

    2014-01-01

    Sustainable, environmental friendly, and safe disposal of sewage treatment plant (STP) sludge is a global expectation. Bioremediation performance was examined at different hydraulic retention times (HRT) in 3-10 days and organic loading rates (OLR) at 0.66-7.81 g chemical oxygen demand (COD) per liter per day, with mixed filamentous fungal (Aspergillus niger and Penicillium corylophilum) inoculation by liquid-state bioconversion (LSB) technique as a continuous process in large-scale bioreactor. Encouraging results were monitored in treated sludge by LSB continuous process. The highest removal of total suspended solid (TSS), turbidity, and COD were achieved at 98, 99, and 93%, respectively, at 10 days HRT compared to control. The minimum volatile suspended solid/suspended solid implies the quality of water, which was recorded 0.59 at 10 days and 0.72 at 3 days of HRT. In treated supernatant with 88% protein removal at 10 days of HRT indicates a higher magnitude of purification of treated sludge. The specific resistance to filtration (SRF) quantifies the performance of dewaterability; it was recorded minimum 0.049 × 10(12) m kg(-1) at 10 days of HRT, which was equivalent to 97% decrease of SRF. The lower OLR and higher HRT directly influenced the bioremediation and dewaterability of STP sludge in LSB process. The obtained findings imply encouraging message in continuing treatment of STP sludge, i.e., bioremediation of wastewater for environmental friendly disposal in near future.

  11. Production of bioethanol by direct bioconversion of oil-palm industrial effluent in a stirred-tank bioreactor.

    Science.gov (United States)

    Alam, Md Zahangir; Kabbashi, Nassereldeen A; Hussin, S Nahdatul I S

    2009-06-01

    The purpose of this study was to evaluate the feasibility of producing bioethanol from palm-oil mill effluent generated by the oil-palm industries through direct bioconversion process. The bioethanol production was carried out through the treatment of compatible mixed cultures such as Thrichoderma harzianum, Phanerochaete chrysosporium, Mucor hiemalis, and yeast, Saccharomyces cerevisiae. Simultaneous inoculation of T. harzianum and S. cerevisiae was found to be the mixed culture that yielded the highest ethanol production (4% v/v or 31.6 g/l). Statistical optimization was carried out to determine the operating conditions of the stirred-tank bioreactor for maximum bioethanol production by a two-level fractional factorial design with a single central point. The factors involved were oxygen saturation level (pO(2)%), temperature, and pH. A polynomial regression model was developed using the experimental data including the linear, quadratic, and interaction effects. Statistical analysis showed that the maximum ethanol production of 4.6% (v/v) or 36.3 g/l was achieved at a temperature of 32 degrees C, pH of 6, and pO(2) of 30%. The results of the model validation test under the developed optimum process conditions indicated that the maximum production was increased from 4.6% (v/v) to 6.5% (v/v) or 51.3 g/l with 89.1% chemical-oxygen-demand removal.

  12. Bioconversion of corn stover derived pentose and hexose to ethanol using cascade simultaneous saccharification and fermentation (CSSF).

    Science.gov (United States)

    Li, Xuan; Kim, Tae Hyun

    2012-01-01

    A cascade type of fermentation, designated the cascade simultaneous saccharification and fermentation (CSSF), was studied to convert corn stover derived pentose and hexose to ethanol with reduced enzyme input. In detail, each step of CSSF utilizes two sequential SSF phases operating on pentose and hexose, i.e., pentose conversion using xylanase, endo-glucanase, and recombinant Escherichia coli (KO11) with minimal glucose conversion in the first phase SSF, and hexose conversion in the second phase SSF using cellulase, β-glucosidase, and Saccharomyces cerevisiae (D(5)A). In this cascade scheme, multiple stages of 1st and 2nd phase SSF were performed in series; enzymes are recycled from the fermentation broth of the last stage for the use of the next stage. This bioconversion process yielded up to 60% of the theoretical maximum ethanol yield based on the total sugars in untreated corn stover, while enzyme loadings were reduced by 50% (v/v) and the final ethanol concentration reached 27 g/l.

  13. Fermentation products of solvent tolerant marine bacterium Moraxella spp. MB1 and its biotechnological applications in salicylic acid bioconversion.

    Directory of Open Access Journals (Sweden)

    Solimabi Wahidullah

    Full Text Available As part of a proactive approach to environmental protection, emerging issues with potential impact on the environment is the subject of ongoing investigation. One emerging area of environmental research concerns pharmaceuticals like salicylic acid, which is the main metabolite of various analgesics including aspirin. It is a common component of sewage effluent and also an intermediate in the degradation pathway of various aromatic compounds which are introduced in the marine environment as pollutants. In this study, biotransformation products of salicylic acid by seaweed, Bryopsis plumosa, associated marine bacterium, Moraxella spp. MB1, have been investigated. Phenol, conjugates of phenol and hydroxy cinnamic acid derivatives (coumaroyl, caffeoyl, feruloyl and trihydroxy cinnamyl with salicylic acid (3-8 were identified as the bioconversion products by electrospray ionization mass spectrometry. These results show that the microorganism do not degrade phenolic acid but catalyses oxygen dependent transformations without ring cleavage. The degradation of salicylic acid is known to proceed either via gentisic acid pathway or catechol pathway but this is the first report of biotransformation of salicylic acid into cinnamates, without ring cleavage. Besides cinnamic acid derivatives (9-12, metabolites produced by the bacterium include antimicrobial indole (13 and β-carbolines, norharman (14, harman (15 and methyl derivative (16, which are beneficial to the host and the environment.

  14. Fermentation products of solvent tolerant marine bacterium Moraxella spp. MB1 and its biotechnological applications in salicylic acid bioconversion.

    Science.gov (United States)

    Wahidullah, Solimabi; Naik, Deepak N; Devi, Prabha

    2013-01-01

    As part of a proactive approach to environmental protection, emerging issues with potential impact on the environment is the subject of ongoing investigation. One emerging area of environmental research concerns pharmaceuticals like salicylic acid, which is the main metabolite of various analgesics including aspirin. It is a common component of sewage effluent and also an intermediate in the degradation pathway of various aromatic compounds which are introduced in the marine environment as pollutants. In this study, biotransformation products of salicylic acid by seaweed, Bryopsis plumosa, associated marine bacterium, Moraxella spp. MB1, have been investigated. Phenol, conjugates of phenol and hydroxy cinnamic acid derivatives (coumaroyl, caffeoyl, feruloyl and trihydroxy cinnamyl) with salicylic acid (3-8) were identified as the bioconversion products by electrospray ionization mass spectrometry. These results show that the microorganism do not degrade phenolic acid but catalyses oxygen dependent transformations without ring cleavage. The degradation of salicylic acid is known to proceed either via gentisic acid pathway or catechol pathway but this is the first report of biotransformation of salicylic acid into cinnamates, without ring cleavage. Besides cinnamic acid derivatives (9-12), metabolites produced by the bacterium include antimicrobial indole (13) and β-carbolines, norharman (14), harman (15) and methyl derivative (16), which are beneficial to the host and the environment.

  15. [Phase transfer catalyzed bioconversion of penicillin G to 6-APA by immobilized penicillin acylase in recyclable aqueous two-phase systems with light/pH sensitive copolymers].

    Science.gov (United States)

    Jin, Ke-ming; Cao, Xue-jun; Su, Jin; Ma, Li; Zhuang, Ying-ping; Chu, Ju; Zhang, Si-liang

    2008-03-01

    Immobilized penicillin acylase was used for bioconversion of penicillin PG into 6-APA in aqueous two-phase systems consisting of a light-sensitive polymer PNBC and a pH-sensitive polymer PADB. Partition coefficients of 6-APA was found to be about 5.78 in the presence of 1% NaCl. Enzyme kinetics showed that the reaction reached equilibrium at roughly 7 h. The 6-APA mole yields were 85.3% (pH 7.8, 20 degrees C), with about 20% increment as compared with the reaction of single aqueous phase buffer. The partition coefficient of PG (Na) varied scarcely, while that of the product, 6-APA and phenylacetic acid (PA) significantly varied due to Donnan effect of the phase systems and hydrophobicity of the products. The variation of the partition coefficients of the products also affected the bioconversion yield of the products. In the aqueous two-phase systems, the substrate, PG, the products of 6-APA and PA were biased in the top phase, while immobilized penicillin acylase at completely partitioned at the bottom. The substrate and PG entered the bottom phase, where it was catalyzed into 6-APA and PA and entered the top phase. Inhibition of the substrate and products was removed to result in improvement of the product yield, and the immobilized enzyme showed higher efficiency than the immobilized cells and occupied smaller volume. Compared with the free enzyme, immobilized enzyme had greater stability, longer life-time, and was completely partitioned in the bottom phase and recycle. Bioconversion in two-phase systems using immobilized penicillin acylase showed outstanding advantage. The light-sensitive copolymer forming aqueous two-phase systems could be recovered by laser radiation at 488 nm or filtered 450 nm light, while pH-sensitive polymer PADB could be recovered at the isoelectric point (pH 4.1). The recovery of the two copolymers was between 95% and 99%.

  16. Large scale solubilization of coal and bioconversion to utilizable energy. Seventh quarterly technical progress report, April 1, 1995--June 30, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, N.C.

    1995-12-01

    In order to develop a system for a large scale coal solubilization and its bioconversion to utilizable fuel, we plan to clone the genes encoding Neurospora protein that facilitate depolymerization of coal. We also plan to use desulfurizing bacteria to remove the sulfur in situ and use other microorganisms to convert biosolubilized coal into utilizable energy following an approach utilizing several microorganisms. In addition the product of coal solubilized by fungus will be characterized to determine their chemical nature and the mechanism of reaction catalyzed by fungal product during in vivo and in vitro solubilization by the fungus or purified fungal protein.

  17. Large scale solubilization of coal and bioconversion to utilizable energy. Eighth quarterly technical progress report, July 1, 1995--September 30, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, N.C.

    1996-02-01

    In order to develop a system for a large scale coal solubilization and its bioconversion to utilizable fuel, we plan to clone the genes encoding Neurospora protein that facilitate depolymerization of coal. We also plan to use desulfurizing bacteria to remove the sulfur in situ and use other microorganisms to convert biosolubilized coal into utilizable energy following an approach utilizing several microorganisms. In addition the product of coal solubilized by fungus will be characterized to determine their chemical nature and the mechanism of reaction catalyzed by fungal product during in vivo and in vitro solubilization by the fungus or purified fungal protein.

  18. Optimization of Eisenia fetida stocking density for the bioconversion of rock phosphate enriched cow dung–waste paper mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Unuofin, F.O., E-mail: funmifrank2009@gmail.com; Mnkeni, P.N.S., E-mail: pmnkeni@ufh.ac.za

    2014-11-15

    Highlights: • Vermidegradation of RP-enriched waste mixtures is dependent on E. fetida stocking density. • A stocking density of 12.5 g-worms kg{sup -1} resulted in highly humified vermicomposts. • P release from RP-enriched waste vermicomposts increases with E. fetida stocking density. • RP-enriched waste vermicomposts had no inhibitory effect on seed germination. - Abstract: Vermitechnology is gaining recognition as an environmental friendly waste management strategy. Its successful implementation requires that the key operational parameters like earthworm stocking density be established for each target waste/waste mixture. One target waste mixture in South Africa is waste paper mixed with cow dung and rock phosphate (RP) for P enrichment. This study sought to establish optimal Eisenia fetida stocking density for maximum P release and rapid bioconversion of RP enriched cow dung–paper waste mixtures. E. fetida stocking densities of 0, 7.5, 12.5, 17.5 and 22.5 g-worms kg{sup −1} dry weight of cow dung–waste paper mixtures were evaluated. The stocking density of 12.5 g-worms kg{sup −1} resulted in the highest earthworm growth rate and humification of the RP enriched waste mixture as reflected by a C:N ratio of <12 and a humic acid/fulvic acid ratio of >1.9 in final vermicomposts. A germination test revealed that the resultant vermicompost had no inhibitory effect on the germination of tomato, carrot, and radish. Extractable P increased with stocking density up to 22.5 g-worm kg{sup −1} feedstock suggesting that for maximum P release from RP enriched wastes a high stocking density should be considered.

  19. Tartronate semialdehyde reductase defines a novel rate-limiting step in assimilation and bioconversion of glycerol in Ustilago maydis.

    Directory of Open Access Journals (Sweden)

    Yanbin Liu

    Full Text Available BACKGROUND: Glycerol is a by-product of biodiesel production. Currently, it has limited applications with low bioconversion efficiency to most metabolites reported. This is partly attributed to the poor knowledge on the glycerol metabolic pathway in bacteria and fungi. METHODOLOGY/PRINCIPAL FINDINGS: We have established a fast screening method for identification of genes that improve glycerol utilization in Ustilago maydis. This was done by comparing the growth rates of T-DNA tagged mutant colonies on solid medium using glycerol as the sole carbon source. We present a detailed characterization of one of the mutants, GUM1, which contains a T-DNA element inserted into the promoter region of UM02592 locus (MIPS Ustilago maydis database, MUMDB, leading to enhanced and constitutive expression of its mRNA. We have demonstrated that um02592 encodes a functional tartronate semialdehyde reductase (Tsr1, which showed dual specificity to cofactors NAD(+ and NADP(+ and strong substrate specificity and enantioselectivity for D-glycerate. Improved glycerol assimilation in GUM1 was associated with elevated expression of tsr1 mRNA and this could be phenocopied by over-expression of the gene. Glycolipid accumulation was reduced by 45.2% in the knockout mutant whereas introduction of an extra copy of tsr1 driven by the glyceraldehyde phosphate dehydrogenase promoter increased it by 40.4%. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that tartronate semialdehyde reductase (TSR plays an important role in glycerol assimilation in U. maydis and defines a novel target in genetic engineering for improved conversion of glycerol to higher value products. Our results add significant depth to the understanding of the glycerol metabolic pathway in fungi. We have demonstrated, for the first time, a biological role of a eukaryotic TSR.

  20. Bioconversion of coal-derived synthesis gas to liquid fuels. Final report, September 29, 1992--December 27, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Jain, M.K.; Worden, R.M.; Grethlein, H.E.

    1995-01-15

    The proposed research project consists of an integrated, two-stage fermentation and a highly energy-efficient product separation scheme. In the first fermentation, Butyribacterium methylotrophicum converts carbon monoxide (CO) into butyric acid and acetic acids which are then converted into butanol, ethanol, and a small amount of acetone in the second stage fermentation by Clostridium acetobutylicum. An advanced separation system process, based on pervaporation, removes the alcohols from the fermentation broth as they are formed, along with some of the hydrogen sulfide (H{sub 2}S), to minimize possible inhibition of the fermentations. This bioconversion process offers a critical advantage over conventional, catalytic processes for synthesis gas conversion: the microorganisms are several orders of magnitude more sulfur tolerant than metallic catalysts. The catalysts require sulfur removal to the parts per million level, while the microorganisms are unaffected by H{sub 2}S and carbonyl sulfide (COS) at one part per hundred--roughly the composition of sulfur in raw synthesis gas. During the two-year course of this project, the following major objectives have been accomplished: demonstrated long-term cell recycle of continuous fermentation of synthesis gas; demonstrated cell immobilization of Butyribacterium methylotrophicum; identified trickle-bed reactor as a viable alternative fermentation method; modulated metabolic pathways to increase C4 formation during synthesis gas fermentation; recovered carbon and electrons from H{sub 2} and CO{sub 2} with pathway modulation for increased C4 production; developed bacterial strains with improved selectivity for butyrate fermentation; demonstrated two-stage CO to alcohol fermentation; and concentrated alcohol from solventogenic fermentation by pervaporation.

  1. Optimization of process parameters for pilot-scale liquid-state bioconversion of sewage sludge by mixed fungal inoculation.

    Science.gov (United States)

    Rahman, Roshanida A; Molla, Abul Hossain; Barghash, Hind F A; Fakhru'l-Razi, Ahmadun

    2016-01-01

    Liquid-state bioconversion (LSB) technique has great potential for application in bioremediation of sewage sludge. The purpose of this study is to determine the optimum level of LSB process of sewage sludge treatment by mixed fungal (Aspergillus niger and Penicillium corylophilum) inoculation in a pilot-scale bioreactor. The optimization of process factors was investigated using response surface methodology based on Box-Behnken design considering hydraulic retention time (HRT) and substrate influent concentration (S0) on nine responses for optimizing and fitted to the regression model. The optimum region was successfully depicted by optimized conditions, which was identified as the best fit for convenient multiple responses. The results from process verification were in close agreement with those obtained through predictions. Considering five runs of different conditions of HRT (low, medium and high 3.62, 6.13 and 8.27 days, respectively) with the range of S0 value (the highest 12.56 and the lowest 7.85 g L(-1)), it was monitored as the lower HRT was considered as the best option because it required minimum days of treatment than the others with influent concentration around 10 g L(-1). Therefore, optimum process factors of 3.62 days for HRT and 10.12 g L(-1) for S0 were identified as the best fit for LSB process and its performance was deviated by less than 5% in most of the cases compared to the predicted values. The recorded optimized results address a dynamic development in commercial-scale biological treatment of wastewater for safe and environment-friendly disposal in near future.

  2. Isolation and evaluation of native cellulose degrading microorganisms for efficient bioconversion of weed biomass and rice straw.

    Science.gov (United States)

    Mahanta, K; Jha, D K; Rajkhowa, D J; Kumar, Manoj

    2014-07-01

    Cellulose decomposing microorganisms (CDMs) are important for efficient bioconversion of plant biomasses. To this end, we isolated seven fungal isolates (Aspergillus wentii, Fusarium solani, Mucor sp., Penicillum sp., Trichoderma harzaianum, Trichoderma sp.1 and Trichoderma sp.2) and three bacterial isolates (bacterial isolate I, II and III) from partially decomposed farm yard manure, rice straw and vermicompost, and evaluated them for decomposition of rice straw (Oryza sativa), Ipomoea camea and Eichhornia crassipes biomass. CDMs inoculation, in general, reduced the composting period by 14-28 days in rice straw, 14-34 days in Eichhornia and 10-28 days in Ipomoea biomass over control. Of the 10 CDMs tested, Mucor sp. was found to be the most effective as Mucor-inoculated biomass required minimum time, i.e. 84, 68 and 80 days respectively for composting of rice straw, Eichhornia and Ipomoea biomass as against 112, 102 and 108 days required under their respective control. CDMs inoculation also narrowed down the C:N ratio of the composts which ranged from 19.1-22.7, 12.9-14.7 and 10.5-13.1 in rice straw, Eichhornia and Ipomoea biomass respectively as against 24.1, 17.1 and 16.2 in the corresponding control treatments. Aspergillus wentii, Fusarium solani, Mucor sp., and Penicillum sp. were found most effective (statistically at par) in reducing C:N ratio and causing maximum loss of carbon and dry matter in composted materials. These benefits of CDMs inoculation were also accompanied by significant increase in NPK contents in the composted materials.

  3. Shiitake Medicinal Mushroom, Lentinus edodes (Higher Basidiomycetes) Productivity and Lignocellulolytic Enzyme Profiles during Wheat Straw and Tree Leaf Bioconversion.

    Science.gov (United States)

    Elisashvili, Vladimir; Kachlishvili, Eva; Asatiani, Mikheil D

    2015-01-01

    Two commercial strains of Lentinus edodes have been comparatively evaluated for their productivity and lignocellulolytic enzyme profiles in mushroom cultivation using wheat straw or tree leaves as the growth substrates. Both substrates are profitable for recycling into shiitake fruit bodies. L. edodes 3715 gave the lowest yield of mushroom during tree leaves bioconversion with the biological efficiency (BE) 74.8% while the L. edodes 3721 BE achieved 83.4%. Cultivation of shiitake on wheat straw, especially in the presence of additional nitrogen source, increased the L. edodes 3721 BE to 92-95.3% owing to the high hydrolases activity and favorable conditions. Despite the quantitative variations, each strain of L. edodes had a similar pattern for secreting enzymes into the wheat straw and tree leaves. The mushrooms laccase and MnP activities were high during substrate colonization and declined rapidly during primordia appearance and fruit body development. While oxidase activity decreased, during the same period cellulases and xylanase activity raised sharply. Both cellulase and xylanase activity peaked at the mature fruit body stage. When mushrooms again shifted to the vegetative growth, oxidase activity gradually increased, whereas the hydrolases activity dropped rapidly. The MnP, CMCase, and FP activities of L. edodes 3721 during cultivation on wheat straw were higher than those during mushroom growth on tree leaves whereas the laccase activity was rather higher in fermentation of tree leaves. Enrichment of wheat straw with an additional nitrogen source rather favored to laccase, MnP, and FPA secretion during the vegetative stage of the L. edodes 3721 growth.

  4. Bioconversion of xylan for drugs, energy and chemical intermediates%木聚糖生物转化药物、能源和化工中间体

    Institute of Scientific and Technical Information of China (English)

    王海洪; 孙晓锋; 吴耀国

    2011-01-01

    Xylan, the second most abundant polysaccharide compared to cellulose,is a kind of polysaccharide widely existing in the nature. It has tremendous potential applications in many fields, especially in the pharmaceutical,energy and chemicals. Bioconversion with advantages of non-polluting and low-energy consumption expands the applications of xylan. The structure of xylan and itS mechanism of enzymatic lycosylation are introduced. The research on bioconversion of xylan into drugs ( xylo-oligosaccharides and xylitol) , energy ( fuel ethanol and 2, 3-butanediol) , and chemical intermediates ( lactic acid and furfural) are described in detail. Enzymatic species , hacteria , zymotic factors and detective methods are comparably studied as well.%介绍了木聚糖的结构与酶糖化机理,综述了国内外对木聚糖生物转化方面的研究.详细介绍了木聚糖转化为低聚木糖和木糖醇等医药食品、燃料乙醇和2,3-丁二醇等能源物质、乳酸和糠醛等化工中间体的研究进展.

  5. Isolation and characterization of bacterial strains with a hydrolytic profile with potential use in bioconversion of agroindustial by-products and waste

    Directory of Open Access Journals (Sweden)

    Cintia Anabela Mazzucotelli

    2013-06-01

    Full Text Available There is a trend towards the use of novel technologies nowadays, mainly focused on biological processes, for recycling and the efficient utilization of organic residues that can be metabolized by different microorganisms as a source of energy. In the present study the isolation of bacterial strains from six different agro-industrial by-products and waste was performed with the objective of evaluating their hydrolytic capacities and suitability for use in bioconversion of specific substrates. The 34 isolated strains were screened in specific culture media for the production of various hydrolytic enzymes (lipase, protease, cellulase, and amylase. It was found that 28 strains exhibited proteolytic activity, 18 had lipolytic activity, 13 had caseinolytic activity, 15 had amylolytic activity, and 11 strains exhibited cellulolytic activity. The strains that showed the highest hydrolytic capacities with biotechnological potential were selected, characterized genotipically, and identified as Bacillus, Serratia, Enterococcus, Klebsiella, Stenotrophomonas, Lactococcus, and Escherichia genera. It was concluded that the strain isolates have a high potential for use in the bioconversion of agro-industrial waste, both as a pure culture and as a microbial consortium.

  6. Bioconversion of α-linolenic acid into n-3 long-chain polyunsaturated fatty acid in hepatocytes and ad hoc cell culture optimisation.

    Directory of Open Access Journals (Sweden)

    Ramez Alhazzaa

    Full Text Available This study aimed to establish optimal conditions for a cell culture system that would allow the measurement of 18:3n-3 (ALA bioconversion into n-3 long-chain polyunsaturated fatty acid (n-3 LC-PUFA, and to determine the overall pathway kinetics. Using rat hepatocytes (FaO as model cells, it was established that a maximum 20:5n-3 (EPA production from 50 µM ALA initial concentration was achieved after 3 days of incubation. Next, it was established that a gradual increase in the ALA concentration from 0 up to 125 µM lead to a proportional increase in EPA, without concomitant increase in further elongated or desaturated products, such as 22:5n-3 (DPA and 22:6n-3 (DHA in 3 day incubations. Of interest, ALA bioconversion products were observed in the culture medium. Therefore, in vitro experiments disregarding the medium fatty acid content are underestimating the metabolism efficiency. The novel application of the fatty acid mass balance (FAMB method on cell culture system (cells with medium enabled quantifying the apparent enzymatic activities for the biosynthesis of n-3 LC-PUFA. The activity of the key enzymes was estimated and showed that, under these conditions, 50% (Km of the theoretical maximal (V max = 3654 µmol.g(-1 of cell protein.hour(-1 Fads2 activity on ALA can be achieved with 81 µM initial ALA. Interestingly, the apparent activity of Elovl2 (20:5n-3 elongation was the slowest amongst other biosynthesis steps. Therefore, the possible improvement of Elovl2 activity is suggested toward a more efficient DHA production from ALA. The present study proposed and described an ad hoc optimised cell culture conditions and methodology towards achieving a reliable experimental platform, using FAMB, to assist in studying the efficiency of ALA bioconversion into n-3 LC-PUFA in vitro. The FAMB proved to be a powerful and inexpensive method to generate a detailed description of the kinetics of n-3 LC-PUFA biosynthesis enzymes activities in vitro.

  7. Development of yeast molecular display systems focused on therapeutic proteins, enzymes, and foods: functional analysis of proteins and its application to bioconversion.

    Science.gov (United States)

    Shibasaki, Seiji; Ueda, Mitsuyoshi

    2010-11-01

    Molecular display systems using yeast have been developed for industrial, medical, pharmaceutical, and biological studies. Although several host cells are available to construct a molecular display system, the yeast Saccharomyces cerevisiae is a well-established and convenient organism in eukaryotes. A wide variety of prokaryotic and eukaryotic proteins have been displayed on yeast cell surfaces. In addition, functional analyses and applications to bioconversion have been performed on the cell surface, and cells are conveniently engineered by molecular display systems. In this review, we focus on the yeast molecular display system with regard to therapeutic proteins, several enzymes, and food ingredients. In addition, recent patents on molecular display using yeast cell for production of those compounds, screening technology and related techniques are introduced. Development of devices for functional analysis of created and modified proteins in the yeast display system is also described.

  8. An improved process of ethanol production from hemicellulose: bioconversion of undetoxified hemicellulosic hydrolyzate from steam-exploded corn stover with a domesticated Pichia stipitis.

    Science.gov (United States)

    Yong, Qiang; Li, Xin; Yuan, Yun; Lai, Chenhuan; Zhang, Nannan; Chu, Qiulu; Xu, Yong; Yu, Shiyuan

    2012-08-01

    Bioconversion of undetoxified hemicellulosic hydrolyzate from steam-exploded corn stover was investigated with a domesticated Pichia stipitis CBS 5776. The countercurrent washing was applied to recover sugars from the steam-exploded corn stover, which could enrich sugars in washing liquor and give an efficient saving of water. Acid concentration, reaction temperature, and time were optimized for the acid post-hydrolysis of oligosaccharides in steam-exploded prehydrolyzate by a central composite design and response surface methodology. The domestication of P. stipitis to the hydrolyzate resulted in improving sugar consumption and ethanol yield by gradually increasing the ratio of hydrolyzate in the medium. Recycling utilization of the domesticated yeast demonstrated that the yeast kept a stable ability of fermenting both hexose and pentose in the undetoxified hydrolyzate. The sugar consumption and ethanol yield were over 90 and 80 %, respectively.

  9. Bioconversion of Agave tequilana fructans by exo-inulinases from indigenous Aspergillus niger CH-A-2010 enhances ethanol production from raw Agave tequilana juice.

    Science.gov (United States)

    Huitrón, Carlos; Pérez, Rosalba; Gutiérrez, Luís; Lappe, Patricia; Petrosyan, Pavel; Villegas, Jesús; Aguilar, Cecilia; Rocha-Zavaleta, Leticia; Blancas, Abel

    2013-01-01

    Agave tequilana fructans are the source of fermentable sugars for the production of tequila. Fructans are processed by acid hydrolysis or by cooking in ovens at high temperature. Enzymatic hydrolysis is considered an alternative for the bioconversion of fructans. We previously described the isolation of Aspergillus niger CH-A-2010, an indigenous strain that produces extracellular inulinases. Here we evaluated the potential application of A. niger CH-A-2010 inulinases for the bioconversion of A. tequilana fructans, and its impact on the production of ethanol. Inulinases were analyzed by Western blotting and thin layer chromatography. Optimal pH and temperature conditions for inulinase activity were determined. The efficiency of A. niger CH-A-2010 inulinases was compared with commercial enzymes and with acid hydrolysis. The hydrolysates obtained were subsequently fermented by Saccharomyces cerevisiae to determine the efficiency of ethanol production. Results indicate that A. niger CH-A-2010 predominantly produces an exo-inulinase activity. Optimal inulinase activity occurred at pH 5.0 and 50 °C. Hydrolysis of raw agave juice by CH-A-2010 inulinases yielded 33.5 g/l reducing sugars, compared with 27.3 g/l by Fructozyme(®) (Novozymes Corp, Bagsværd, Denmark) and 29.4 g/l by acid hydrolysis. After fermentation of hydrolysates, we observed that the conversion efficiency of sugars into ethanol was 97.5 % of the theoretical ethanol yield for enzymatically degraded agave juice, compared to 83.8 % for acid-hydrolyzed juice. These observations indicate that fructans from raw Agave tequilana juice can be efficiently hydrolyzed by using A. niger CH-A-2010 inulinases, and that this procedure impacts positively on the production of ethanol.

  10. Bioconversion of D-galacturonate to keto-deoxy-L-galactonate (3-deoxy-L-threo-hex-2-ulosonate using filamentous fungi

    Directory of Open Access Journals (Sweden)

    Wiebe Marilyn G

    2010-08-01

    Full Text Available Abstract Background The D-galacturonic acid derived from plant pectin can be converted into a variety of other chemicals which have potential use as chelators, clarifiers, preservatives and plastic precursors. Among these is the deoxy-keto acid derived from L-galactonic acid, keto-deoxy-L-galactonic acid or 3-deoxy-L-threo-hex-2-ulosonic acid. The keto-deoxy sugars have been found to be useful precursors for producing further derivatives. Keto-deoxy-L-galactonate is a natural intermediate in the fungal D-galacturonate metabolic pathway, and thus keto-deoxy-L-galactonate can be produced in a simple biological conversion. Results Keto-deoxy-L-galactonate (3-deoxy-L-threo-hex-2-ulosonate accumulated in the culture supernatant when Trichoderma reesei Δlga1 and Aspergillus niger ΔgaaC were grown in the presence of D-galacturonate. Keto-deoxy-L-galactonate accumulated even if no metabolisable carbon source was present in the culture supernatant, but was enhanced when D-xylose was provided as a carbon and energy source. Up to 10.5 g keto-deoxy-L-galactonate l-1 was produced from 20 g D-galacturonate l-1 and A. niger ΔgaaC produced 15.0 g keto-deoxy-L-galactonate l-1 from 20 g polygalacturonate l-1, at yields of 0.4 to 1.0 g keto-deoxy-L-galactonate [g D-galacturonate consumed]-1. Keto-deoxy-L-galactonate accumulated to concentrations of 12 to 16 g l-1 intracellularly in both producing organisms. This intracellular concentration was sustained throughout production in A. niger ΔgaaC, but decreased in T. reesei. Conclusions Bioconversion of D-galacturonate to keto-deoxy-L-galactonate was achieved with both A. niger ΔgaaC and T. reesei Δlga1, although production (titre, volumetric and specific rates was better with A. niger than T. reesei. A. niger was also able to produce keto-deoxy-L-galactonate directly from pectin or polygalacturonate demonstrating the feasibility of simultaneous hydrolysis and bioconversion. Although keto

  11. Soymilk residue (okara as a natural immobilization carrier for Lactobacillus plantarum cells enhances soymilk fermentation, glucosidic isoflavone bioconversion, and cell survival under simulated gastric and intestinal conditions

    Directory of Open Access Journals (Sweden)

    Xia Xiudong

    2016-11-01

    Full Text Available Cell immobilization is an alternative to microencapsulation for the maintenance of cells in a liquid medium. However, artificial immobilization carriers are expensive and pose a high safety risk. Okara, a food-grade byproduct from soymilk production, is rich in prebiotics. Lactobacilli could provide health enhancing effects to the host. This study aimed to evaluate the potential of okara as a natural immobilizer for L. plantarum 70810 cells. The study also aimed to evaluate the effects of okara-immobilized L. plantarum 70810 cells (IL on soymilk fermentation, glucosidic isoflavone bioconversion, and cell resistance to simulated gastric and intestinal stresses. Scanning electron microscopy (SEM was used to show cells adherence to the surface of okara. Lactic acid, acetic acid and isoflavone analyses in unfermented and fermented soymilk were performed by HPLC with UV detection. Viability and growth kinetics of immobilized and free L. plantarum 70810 cells (FL were followed during soymilk fermentation. Moreover, changes in pH, titrable acidity and viscosity were measured by conventional methods. For in vitro testing of simulated gastrointestinal resistance, fermented soymilk was inoculated with FL or IL and an aliquot incubated into acidic MRS broth which was conveniently prepared to simulate gastric, pancreatic juices and bile salts. Survival to simulated gastric and intestinal stresses was evaluated by plate count of colony forming units on MRS agar. SEM revealed that the lactobacilli cells attached and bound to the surface of okara. Compared with FL, IL exhibited a significantly higher specific growth rate, shorter lag phase of growth, higher productions of lactic and acetic acids, a faster decrease in pH and increase in titrable acidity, and a higher soymilk viscosity. Similarly, IL in soymilk showed higher productions of daizein and genistein compared with the control. Compared with FL, IL showed reinforced resistance to simulatedgastric and

  12. The chiral bioconversion and preclinical pharmacokinetic analysis of (R)-(+)-rabeprazole in beagle dogs by HPLC and HPLC-MS/MS.

    Science.gov (United States)

    Gao, Yan-hui; Xu, Jia-xing; Su, Zhong-xue; Song, Li; Lou, Hong-xiang

    2013-11-01

    In order to accurately investigate the preclinical pharmacokinetics of (R)-(+)-rabeprazole sodium injection, a reliable high-performance liquid chromatography (HPLC) method was developed using a Chiral-AGP column to prove that there is no chiral bioconversion of (R)-(+)-rabeprazole to (S)-(-)-rabeprazole in beagle dogs after single intravenous administration of (R)-(+)-rabeprazole sodium injection. An HPLC-tandem mass spectrometry (HPLC-MS/MS) method for analysis of (R)-(+)-rabeprazole was developed and validated, and used to acquire the pharmacokinetic parameters in beagle dogs. (R)-(+)-Rabeprazole and internal standard omeprazole were extracted from plasma samples by protein precipitation and separated on a C18 column using methanol-5 mm ammonium acetate as mobile phase. Detection was performed using a turbo-spray ionization source and mass spectrometric positive multi-reaction monitoring mode. The linear relationship was achieved in the range from 2.5 to 5000 ng/mL. The method also afforded satisfactory results in terms of sensitivity, specificity, precision, accuracy and recovery as well as the stability of the analyte under various conditions, and was successfully applied to a preclinical pharmacokinetic study in beagle dogs after single intravenous administrations of (R)-(+)-rabeprazole sodium injection at 0.33, 2 and 6 mg/kg.

  13. Effect of irradiation, as a pretreatment, on bioconversion of corn stover into protein-rich mycelial biomass of Pleurotus sajor-caju

    Science.gov (United States)

    Awafo, V. A.; Chahal, D. S.; Charbonneau, R.

    1995-09-01

    Application of irradiation for food preservation, for pretreatment of lignocellulosic materials for their hydrolysis and to increase the digestibility of lignocellulosic materials for rumen animals have been reported in the literature. In the present study, irradiation (100 KGy to 1.7 MGy) of corn stover as a pretreatment to make it susceptible for its bioconversion into protein-rich mycelial biomass of Pleurotus sajor-caju NRRL 18757 has been compared with that of mild alkali treatment (0.01 to 0.15 g NaOH/g corn stover), the most commonly used pretreatment. Protein synthesis increased with the increase in doses of irradiation as well as with the increase in concentration of NaOH. Combination pretreatment with NaOH and γ-irradiation reduced the quantity of NaOH and doses of irradiation required to get optimum yields of protein indicating a strong synergistic effect. The highest protein content of the final product, mycelial biomass, was about 45% on dry weight basis. More than 90% utilization of corn stover polysaccharides for the synthesis of protein-rich mycelial biomass of P. sajor-caju was recorded

  14. Solid-state bioconversion of chickpea (Cicer arietinum L.) by Rhizopus oligosporus to improve total phenolic content, antioxidant activity and hypoglycemic functionality.

    Science.gov (United States)

    Sánchez-Magaña, Luis Martin; Cuevas-Rodríguez, Edith Oliva; Gutiérrez-Dorado, Roberto; Ayala-Rodríguez, Ana Edith; Valdez-Ortiz, Angel; Milán-Carrillo, Jorge; Reyes-Moreno, Cuauhtémoc

    2014-08-01

    The objective of this investigation was to study the effect of time during solid state bioconversion (SSB) on total phenolic content (TPC), antioxidant activity (AoxA), and inhibitory properties against α-amylase and α-glucosidase of chickpea. Chickpea cotyledons were inoculated with a suspension of Rhizopus oligosporus and incubated at 35 °C for 24, 36, 48, 60, 72, 84, 96 and 108 h. The best time to produce bioprocessed chickpea (added with seed coats) flour with the highest AoxA was 108 h. SSB substantially increased TPC and AoxA of chickpea extracts in 2.78 and 1.80-1.94 times, respectively. At 36 and 96 h of fermentation, the SSB process improved in vitro α-amylase and α-glucosidase inhibition (AI and GI indexes) activities of chickpea extracts in 83 and 370%, respectively. SSB is a good strategy to enhance health-linked functionality of chickpea, due to improved TPC, AoxA and content of strong natural inhibitors of enzymes associated with diabetes.

  15. Bioconversion of Cyanidin-3-Rutinoside to Cyanidin-3-Glucoside in Black Raspberry by Crude α-L-Rhamnosidase from Aspergillus Species.

    Science.gov (United States)

    Lim, Taehwan; Jung, Hana; Hwang, Keum Taek

    2015-11-01

    Cyanidin-3-glucoside (C3G) has been known to be more bioavailable than cyanidin-3- rutinoside (C3R), the most abundant anthocyanin in black raspberry (Rubus occidentalis). The aim of this study was to enhance the bioavailability of anthocyanins in black raspberry by cleaving L-rhamnose in C3R using crude enzyme extracts (CEEs) from Aspergillus usamii KCTC 6956, A. awamori KCTC 60380, A. niger KCCM 11724, A. oryzae KCCM 12698, and A. kawachii KCCM 32819. The enzyme activities of the CEEs were determined by a spectrophotometric method using rho-nitrophenyl-rhamnopyranoside and rho-nitrophenyl-glucopyranoside. The CEE from A. usamii had the highest α-L-rhamnosidase activity with 2.73 U/ml at 60°C, followed by those from A. awamori and A. niger. When bioconversion of C3R to C3G in black raspberry was analyzed by HPLC-DAD, the CEEs from A. usamii and A. awamori hydrolyzed 95.7% and 95.6% of C3R to C3G, respectively, after 2 h incubation. The CEEs from A. kawachii and A. oryzae did not convert C3R to C3G in black raspberry.

  16. Bioconversion of Pinoresinol Diglucoside and Pinoresinol from Substrates in the Phenylpropanoid Pathway by Resting Cells of Phomopsis sp.XP-8.

    Directory of Open Access Journals (Sweden)

    Yan Zhang

    Full Text Available Pinoresinol diglucoside (PDG and pinoresinol (Pin are normally produced by plant cells via the phenylpropanoid pathway. This study reveals the existence of a related pathway in Phomopsis sp. XP-8, a PDG-producing fungal strain isolated from the bark of the Tu-chung tree (Eucommiaulmoides Oliv.. After addition of 0.15 g/L glucose to Phomopsis sp. XP-8, PDG and Pin formed when phenylalanine, tyrosine, leucine, cinnamic acid, and p-coumaric acid were used as the substrates respectively. No PDG formed in the absence of glucose, but Pin was detected after addition of all these substrates except leucine. In all systems in the presence of glucose, production of PDG and/or Pin and the accumulation of phenylalanine, cinnamic acid, or p-coumaric acid correlated directly with added substrate in a time- and substrate concentration- dependent manner. After analysis of products produced after addition of each substrate, the mass flow sequence for PDG and Pin biosynthesis was defined as: glucose to phenylalanine, phenylalanine to cinnamic acid, then to p-coumaric acid, and finally to Pin or PDG. During the bioconversion, the activities of four key enzymes in the phenylpropanoid pathway were also determined and correlated with accumulation of their corresponding products. PDG production by Phomopsis sp. exhibits greater efficiency and cost effectiveness than the currently-used plant-based system and will pave the way for large scale production of PDG and/or Pin for medical applications.

  17. Bioconversion of Pinoresinol Diglucoside and Pinoresinol from Substrates in the Phenylpropanoid Pathway by Resting Cells of Phomopsis sp.XP-8.

    Science.gov (United States)

    Zhang, Yan; Shi, Junling; Liu, Laping; Gao, Zhenhong; Che, Jinxin; Shao, Dongyan; Liu, Yanlin

    2015-01-01

    Pinoresinol diglucoside (PDG) and pinoresinol (Pin) are normally produced by plant cells via the phenylpropanoid pathway. This study reveals the existence of a related pathway in Phomopsis sp. XP-8, a PDG-producing fungal strain isolated from the bark of the Tu-chung tree (Eucommiaulmoides Oliv.). After addition of 0.15 g/L glucose to Phomopsis sp. XP-8, PDG and Pin formed when phenylalanine, tyrosine, leucine, cinnamic acid, and p-coumaric acid were used as the substrates respectively. No PDG formed in the absence of glucose, but Pin was detected after addition of all these substrates except leucine. In all systems in the presence of glucose, production of PDG and/or Pin and the accumulation of phenylalanine, cinnamic acid, or p-coumaric acid correlated directly with added substrate in a time- and substrate concentration- dependent manner. After analysis of products produced after addition of each substrate, the mass flow sequence for PDG and Pin biosynthesis was defined as: glucose to phenylalanine, phenylalanine to cinnamic acid, then to p-coumaric acid, and finally to Pin or PDG. During the bioconversion, the activities of four key enzymes in the phenylpropanoid pathway were also determined and correlated with accumulation of their corresponding products. PDG production by Phomopsis sp. exhibits greater efficiency and cost effectiveness than the currently-used plant-based system and will pave the way for large scale production of PDG and/or Pin for medical applications.

  18. Effect of irradiation, as a pretreatment, on bioconversion of corn stover into protein-rich mycelial biomass of Pleurotus sajor-caju

    Energy Technology Data Exchange (ETDEWEB)

    Awafo, V.A.; Chahal, D.S.; Charbonneau, R. [Universite du Quebec (Canada). Applied Microbiology Research Center

    1995-10-01

    Application of irradiation for food preservation, for pretreatment of lignocellulosic materials for their hydrolysis and to increase the digestibility of lignocellulosic materials for rumen animals have been reported in the literature. In the present study, irradiation (100 KGy to 1.7 MGy) of corn stover as a pretreatment to make it susceptible for its bioconversion into protein-rich mycelial biomass of Pleurotus sajor-caju NRRL 18757 has been compared with that of mild alkali treatment (0.01 to 0.15 g NaOH/g corn stover), the most commonly used pretreatment. Protein synthesis increased with the increase in doses of irradiation as well as with the increase in concentration of NaOH. Combination pretreatment with NaOH and {gamma}-irradiation reduced the quantity of NaOH and doses of irradiation required to get optimum yields of protein indicating a strong synergistic effect. The highest protein content of the final product, mycelial biomass, was about 45% on dry weight basis. More than 90% utilization of corn stover polysaccharides for the synthesis of protein-rich mycelial biomass of P. sajor-caju was recorded. (author).

  19. Isolation and Characterization of a Novel Rebaudioside M Isomer from a Bioconversion Reaction of Rebaudioside A and NMR Comparison Studies of Rebaudioside M Isolated from Stevia rebaudiana Bertoni and Stevia rebaudiana Morita

    OpenAIRE

    Indra Prakash; Cynthia Bunders; Krishna P. Devkota; Romila D. Charan; Catherine Ramirez; Christopher Priedemann; Avetik Markosyan

    2014-01-01

    A minor product, rebaudioside M2 (2), from the bioconversion reaction of rebaudioside A (4) to rebaudioside D (3), was isolated and the complete structure of the novel steviol glycoside was determined. Rebaudioside M2 (2) is considered an isomer of rebaudioside M (1) and contains a relatively rare 1→6 sugar linkage. It was isolated and characterized with NMR (1H, 13C, COSY, HSQC-DEPT, HMBC, 1D-TOCSY, and NOESY) and mass spectral data. Additionally, we emphasize the importance of 1D and 2D NMR...

  20. 一株孕酮转化工程菌的构建%Construction of genetically engineered strain for bioconversion of progesterone

    Institute of Scientific and Technical Information of China (English)

    刘园园; 魏维; 戈梅; 陈代杰

    2015-01-01

    孕酮既是临床常用药物、又是可的松等药物的重要中间体,因此简便而快速的生产孕酮方法对于甾体激素的生产具有重要意义。本文利用红平红球菌的胆固醇氧化酶基因,构建了重组质粒BL21/pET28b-choE、并在大肠杆菌中获得重组表达。该菌株能够以孕烯醇酮为底物、转化生产孕酮。经条件优化,对浓度为0.2 g/L的孕烯醇酮的转化率大于80%。%Progesterone is not only a commonly used drug in clinic,but also a kind of important medicine intermediate in cortisol or cortisone synthesis. Thus a convenient method to produce progesterone is important in steroid drug production. In this study,a recombinant plasmid BL21/pET28b-choE was constructed by cloning choE gene from Rhodococcus erythropolis CGMCC 1. 2362 to express cholesterol oxidase in E. coli. Results showed that this recombinant strain could transform pregnenolone to progesterone. When the concentration of pregnenolone was up to 0. 2 g/L,the bioconversion efficiency was more than 80%.

  1. Breakdown kinetics of C-hydroxymethyl beta-dicarbonyl derivatives of carbon acids: implications in the bioconversion rate of C-phosphoryloxymethyl prodrugs of carbon acids.

    Science.gov (United States)

    Dhareshwar, Sundeep S; Stella, Valentino J

    2009-05-01

    The kinetics of conversion of C-hydroxymethyl derivatives of pharmaceutically relevant beta-dicarbonyl carbon acids of two series, pyrazolidin-3,5-diones and inden-1,3-diones, and a model carbon acid back to the respective carbon acids were studied as a function of pH at 25 degrees C and an ionic strength of 0.15 M. This is a somewhat surprising reaction since it involves the facile breakdown of a carbon-carbon bond. The slopes of the pH-rate profiles for the dehydroxymethylation were approximately unity, which along with the lack of buffer catalysis, indicates a specific-base mechanism involving spontaneous breakdown of the oxymethyl anion. This breakdown generates the conjugate base of the respective carbon acids. Thus within a series, there exists a correlation between the second-order rate constant for dehydroxymethylation and the pK(a) of the corresponding carbon acid with a shorter conversion/dehydroxymethylation half-life (at all given pH values) with decreasing pK(a) of the parent carbon acid. The increasing acidity of the carbon acid affords an increase in the leaving group ability of the carbanion, and therefore facilitation of the rate-determining unimolecular carbon-carbon bond cleavage. Since the hydroxymethyl derivative is an intermediate in the bioconversion of C-phosphoryloxymethyl prodrugs of carbon acids, also under study, the relationship allows one to reasonably predict how facile the dehydroxymethylation would be for any new beta-dicarbonyl carbon acid.

  2. Transcriptome analysis of Pseudomonas mediterranea and P. corrugata plant pathogens during accumulation of medium-chain-length PHAs by glycerol bioconversion.

    Science.gov (United States)

    Licciardello, Grazia; Ferraro, Rosario; Russo, Marcella; Strozzi, Francesco; Catara, Antonino F; Bella, Patrizia; Catara, Vittoria

    2017-07-25

    Pseudomonas corrugata and P. mediterranea are soil inhabitant bacteria, generally living as endophytes on symptomless plants and bare soil, but also capable of causing plant diseases. They share a similar genome size and a high proteome similarity. P. corrugata produces many biomolecules which play an important role in bacterial cell survival and fitness. Both species produce different medium-chain-length PHAs (mcl-PHAs) from the bioconversion of glycerol to a transparent film in P. mediterranea and a sticky elastomer in P. corrugata. In this work, using RNA-seq we investigated the transcriptional profiles of both bacteria at the early stationary growth phase with glycerol as the carbon source. Quantitative analysis of P. mediterranea transcripts versus P. corrugata revealed that 1756 genes were differentially expressed. A total of 175 genes were significantly upregulated in P. mediterranea, while 217 were downregulated. The largest group of upregulated genes was related to transport systems and stress response, energy and central metabolism, and carbon metabolism. Expression levels of most genes coding for enzymes related to PHA biosynthesis and central metabolic pathways showed no differences or only slight variations in pyruvate metabolism. The most relevant result was the significantly increased expression in P. mediterranea of genes involved in alginate production, an important exopolysaccharide, which in other Pseudomonas spp. plays a key role as a virulence factor or in stress tolerance and shows many industrial applications. In conclusion, the results provide useful information on the co-production of mcl-PHAs and alginate from glycerol as carbon source by P. mediterranea in the design of new strategies of genetic regulation to improve the yield of bioproducts or bacterial fitness.

  3. Isolation and Characterization of a Novel Rebaudioside M Isomer from a Bioconversion Reaction of Rebaudioside A and NMR Comparison Studies of Rebaudioside M Isolated from Stevia rebaudiana Bertoni and Stevia rebaudiana Morita

    Directory of Open Access Journals (Sweden)

    Indra Prakash

    2014-03-01

    Full Text Available A minor product, rebaudioside M2 (2, from the bioconversion reaction of rebaudioside A (4 to rebaudioside D (3, was isolated and the complete structure of the novel steviol glycoside was determined. Rebaudioside M2 (2 is considered an isomer of rebaudioside M (1 and contains a relatively rare 1→6 sugar linkage. It was isolated and characterized with NMR (1H, 13C, COSY, HSQC-DEPT, HMBC, 1D-TOCSY, and NOESY and mass spectral data. Additionally, we emphasize the importance of 1D and 2D NMR techniques when identifying complex steviol glycosides. Numerous NMR spectroscopy studies of rebaudioside M (1, rebaudioside D (3, and mixture of 1 and 3 led to the discovery that SG17 which was previously reported in literature, is a mixture of rebaudioside D (3, rebaudioside M (1, and possibly other related steviol glycosides.

  4. Isolation and characterization of a novel rebaudioside M isomer from a bioconversion reaction of rebaudioside A and NMR comparison studies of rebaudioside M isolated from Stevia rebaudiana Bertoni and Stevia rebaudiana Morita.

    Science.gov (United States)

    Prakash, Indra; Bunders, Cynthia; Devkota, Krishna P; Charan, Romila D; Ramirez, Catherine; Priedemann, Christopher; Markosyan, Avetik

    2014-03-31

    A minor product, rebaudioside M2 (2), from the bioconversion reaction of rebaudioside A (4) to rebaudioside D (3), was isolated and the complete structure of the novel steviol glycoside was determined. Rebaudioside M2 (2) is considered an isomer of rebaudioside M (1) and contains a relatively rare 1→6 sugar linkage. It was isolated and characterized with NMR (1H, 13C, COSY, HSQC-DEPT, HMBC, 1D-TOCSY, and NOESY) and mass spectral data. Additionally, we emphasize the importance of 1D and 2D NMR techniques when identifying complex steviol glycosides. Numerous NMR spectroscopy studies of rebaudioside M (1), rebaudioside D (3), and mixture of 1 and 3 led to the discovery that SG17 which was previously reported in literature, is a mixture of rebaudioside D (3), rebaudioside M (1), and possibly other related steviol glycosides.

  5. Isolation and Characterization of a Novel Rebaudioside M Isomer from a Bioconversion Reaction of Rebaudioside A and NMR Comparison Studies of Rebaudioside M Isolated from Stevia rebaudiana Bertoni and Stevia rebaudiana Morita

    Science.gov (United States)

    Prakash, Indra; Bunders, Cynthia; Devkota, Krishna P.; Charan, Romila D.; Ramirez, Catherine; Priedemann, Christopher; Markosyan, Avetik

    2014-01-01

    A minor product, rebaudioside M2 (2), from the bioconversion reaction of rebaudioside A (4) to rebaudioside D (3), was isolated and the complete structure of the novel steviol glycoside was determined. Rebaudioside M2 (2) is considered an isomer of rebaudioside M (1) and contains a relatively rare 1→6 sugar linkage. It was isolated and characterized with NMR (1H, 13C, COSY, HSQC-DEPT, HMBC, 1D-TOCSY, and NOESY) and mass spectral data. Additionally, we emphasize the importance of 1D and 2D NMR techniques when identifying complex steviol glycosides. Numerous NMR spectroscopy studies of rebaudioside M (1), rebaudioside D (3), and mixture of 1 and 3 led to the discovery that SG17 which was previously reported in literature, is a mixture of rebaudioside D (3), rebaudioside M (1), and possibly other related steviol glycosides. PMID:24970220

  6. Removal of h2s during anaerobic bioconversion of dairy manure%去除牛粪厌氧生物转化过程中的H2S

    Institute of Scientific and Technical Information of China (English)

    Jam Saifullah Lar; 李秀金

    2009-01-01

    The main aim of this research was the experimental study at lab scale to check the absorption technolOgytor the in situ removal of H2S from biogas during anaerobic digestion process.The reagent FeCll was used to check the removal efficiency of H,S produced from dairy manure during anaerobic bioconversion process.The expenments werc conducted under mesophilic conditions.Thc composition of biogas was analyzed by gas chromatography analyzer equipped with flame photometer and thermal conductivity detectors.Experimental results under the same conditions demonstrate that high concentration of HES in the form of FeS can be removed totally from the biogas using FeCl3 dosing with in anaerobic batch digester.

  7. Bioconversion of α-linolenic acid to n-3 LCPUFA and expression of PPAR-alpha, acyl Coenzyme A oxidase 1 and carnitine acyl transferase I are incremented after feeding rats with α-linolenic acid-rich oils.

    Science.gov (United States)

    González-Mañán, Daniel; Tapia, Gladys; Gormaz, Juan Guillermo; D'Espessailles, Amanda; Espinosa, Alejandra; Masson, Lilia; Varela, Patricia; Valenzuela, Alfonso; Valenzuela, Rodrigo

    2012-07-01

    High dietary intake of n-6 fatty acids in relation to n-3 fatty acids may generate health disorders, such as cardiovascular and other chronic diseases. Fish consumption rich in n-3 fatty acids is low in Latin America, it being necessary to seek other alternatives to provide α-linolenic acid (ALA), precursor of n-3 LCPUFA (EPA and DHA). Two innovative oils were assayed, chia (Salvia hispanica) and rosa mosqueta (Rosa rubiginosa). This study evaluated hepatic bioconversion of ALA to EPA and DHA, expression of PPAR-α, acyl-Coenzyme A oxidase 1 (ACOX1) and carnitine acyltransferase I (CAT-I), and accumulation of EPA and DHA in plasma and adipose tissue in Sprague-Dawley rats. Three experimental groups were fed 21 days: sunflower oil (SFO, control); chia oil (CO); rosa mosqueta oil (RMO). Fatty acid composition of total lipids and phospholipids from plasma, hepatic and adipose tissue was assessed by gas-liquid chromatography and TLC. Expression of PPAR-α (RT-PCR) and ACOX1 and CAT-I (Western blot). CO and RMO increased plasma, hepatic and adipose tissue levels of ALA, EPA and DHA and decreased n-6:n-3 ratio compared to SFO (p < 0.05, One-way ANOVA and Newman-Keuls test). CO increased levels of ALA and EPA compared to RMO (p < 0.05). No significant differences were observed for DHA levels. CO also increased the expression of PPAR-α, ACOX1 and CAT-I. Only CAT-I levels were increased by RO. CO and RMO may be a nutritional alternative to provide ALA for its bioconversion to EPA and DHA, and to increase the expression of PPAR-α, ACOX1 and CAT-I, especially CO-oil.

  8. 甜菊糖苷的生物合成途径与生物转化制备策略的研究概述%Study of steviol glycosides biosynthesis pathway and the advances in its bioconversion strategies

    Institute of Scientific and Technical Information of China (English)

    李铭敏; 郑仁朝; 郑裕国

    2015-01-01

    Steviol glycosides are natural sweetening agents found in the leaves of S.rebaudiana and can be widely used in food and pharmaceutical industries due to their low-calorie and high sweetness.In plants, the methylerythritol 4-phosphate pathway supplies isopentenyl pyrophosphate to produce steviol, which is converted to steviol glycosides by UDP-dependent glycosyltransferases.The taste of steviol glycosides can be improved by introducing crucial enzymes involved in the various bioconversion processes based on the biosynthetic pathway.As such, the biosynthetic pathway and the bioconversion strategies will be explored and reviewed in this paper.%甜菊糖苷(steviol glycosides,SGs)是从甜菊叶片中提取的天然甜味剂,具有低热量、高甜度的特性,可作为食品和医药添加剂.在植物体内,通过甲基赤藓糖醇途径合成的异戊烯焦磷酸能够转化成甜菊醇.甜菊醇在各类UDP-糖基转移酶作用下,糖基化生成各类SGs.在SGs生物合成途径基础上,通过生物转化方法合成相关酶,改善了SGs的味质.文中就其生物合成途径和生物转化制备策略的研究现状进行了综述.

  9. 丙烯酰胺转化菌的分离筛选及其产酶条件%Screening of acrylamide bioconversion bacterium and of its nitrile hydratase producing conditions

    Institute of Scientific and Technical Information of China (English)

    孙先锋; 沈旭丰; 吕小明; 周飞

    2009-01-01

    A strain T3, which has the better ability of acrylamide bioconversion, was isolated from activated sludge in wastewater treatment system at an acrylic fiber factory. T3 is primarily identified as Rhodococcus sp. according to its mor-phological observation. The process conditions producing nitrile hydratase for T3 were investigated. The results indicated that optimal conditions are initial medium pH 7. 5, culture temperature 35℃ and culture time 72h; And the study also showed that 0. 05g/L Co2+ is very important to improving enzyme activity. Under the optimum fermentation conditions, the enzyme activity of T3 cell culture fluid may reaches its maximum value 128.3U/mg, which increased by 55. 1% than before.%从腈纶厂污水处理系统的活性污泥中分离和筛选到一株丙烯酰胺转化菌.经初步鉴定,菌株T3属于红球菌属(Rlwdococcus sp.).对菌株T3产生腈水合酶的最适条件进行研究,结果表明,该菌株的最适产酶条件为培养基初始pH值7.5,培养温度35℃,培养时间72h,同时加入0.05g/L Co2+也会明显提高酶活性.在最适产酶条件下,菌株,13培养液的最高比酶活可达128.3U/mg,比优化前提高55.1%.

  10. 生物转化食用菌菌糠木质纤维素产燃料乙醇的研究进展%Research progresses on bioconversion of spent mushroom substrate lignocellulose for fuel ethanol production

    Institute of Scientific and Technical Information of China (English)

    虞志强; 余水静; 李昆太

    2015-01-01

    近年来,食用菌生产技术在世界各国得以广泛普及,全球食用菌菌糠(spent mushroom substrate,SMS)总产量也随之大幅增长.随着全球性能源危机的到来,利用可再生纤维素类物质生产燃料乙醇已引起世界各国的高度重视.食用菌菌糠是食用菌子实体采收后的固体废弃物,其含有纤维素、半纤维素、木质素、抗营养因子和胞外纤维素降解酶类等组分,具备了作为第二代生物乙醇转化基质的潜力,基于此,该文对当前利用食用菌菌糠生物转化生产乙醇的研究进展和应用前景进行了阐述.%In recent years,edible fungus production technology has been widely spread all over the world,and the total output of spent mushroom substrate (SMS) has been significantly increased.With the severe circumstances of the global energy crisis,more and more attention has been focused on how to use the renewable fiber material to produce bioethanol.As the solid waste of mushroom,SMS contains lots of nutritional ingredients,such as cellulose,hemicellulose,lignin,anti-nutrition factor and extracellular cellulose degradation enzymes,and possesses the potential of second-generation bioethanol conversion.The second-generation bioethanol made from lignocellulosic biomass is considered to be one of the most promising biofuels.Based on this fact,this paper mainly elaborated the research progresses and application prospect on the utilization of SMS for ethanol bioconversion.

  11. Evaluation of the hepatic bioconversion of α-linolenic acid (ALA to eicosapentaenoic acid (EPA and docosahexaenoic acid (DHA in rats fed with oils from chia (Salvia hispánica or rosa mosqueta (Rosa rubiginosa

    Directory of Open Access Journals (Sweden)

    Tapia O., G.

    2012-03-01

    Full Text Available The high dietary intake of n-6 fatty acids in relation to n-3 fatty acids generates health disorders, such as cardiovascular diseases, inflammatory diseases and other chronic diseases. The consumption of fish, which is rich in n-3 fatty acids, is low in Latin America and it is necessary to seek other alternatives, such as chia oil (CO or rosa mosqueta oil (RMO, which are rich in α-linolenic acid (ALA, the precursor of the n -3 fatty acids, eicosapentaenoic acid (EPA and docosahexaenoic acid (DHA. This study evaluates the hepatic bioconversion of ALA to EPA and DHA and the damage to the liver (histology and transaminase in Sprague- Dawley rats fed different vegetable oils. Four experimental groups (n = 9 animals each group were fed the following dietary supplements for 21 days: a sunflower oil (SFO, b RMO, c CO d olive oil with fish oil added (EPA and DHA (OO/FO. RMO and CO increased the hepatic levels of ALA, EPA and DHA and decreased the n-6/n-3 ratio compared to SFO (p El elevado aporte en la dieta de ácidos grasos omega- 6, en relación a los ácidos grasos omega-3, genera alteraciones de la salud cardiovascular, inflamación y otras patologías crónicas no transmisibles. Por otro lado, el pescado rico en ácidos grasos omega-3 es de bajo consumo en Latinoamérica, siendo necesario buscar otras alternativas de aporte de ácidos grasos omega-3, como lo son el aceite de chía (CO o el de rosa mosqueta (RMO, ricos en ácido α-linolénico (ALA, que es el precursor de los ácidos grasos omega-3, eicosapentaenoico (EPA y docosahexaenoico (DHA. Este trabajo evaluó en forma preliminar la bioconversión hepática del ALA en EPA y DHA y el daño hepático (histología y transaminasas en ratas Sprague-Dawley alimentadas con diferentes aceites vegetales. Se conformaron cuatro grupos experimentales (n = 9 animales por grupo que recibieron durante 21 días: a aceite de girasol (SFO; b RMO, c CO y d aceite de oliva adicionado de aceite de pescado (EPA

  12. Evaluasi Perlakuan Pendahuluan Menggunakan Kalsium Hidroksida untuk Biokonversi Jerami Padi Menjadi L-Asam Laktat oleh Rhizopus oryzae AT3 (Evaluation of Lime Pretreatment for Bioconversion of Rice Straw to L-Lactic Acid by Rhizopus Oryzae AT3

    Directory of Open Access Journals (Sweden)

    Dhina Aprilia Nurani Widyahapsari

    2016-12-01

    Full Text Available L-lactic acid can be used as a precursor of polylactic acid (PLA. PLA is a biodegradable biomaterial commonly used for biodegradable plastics. Lactic acid can be produced from lignocelluloses materials such as rice straw. Rice straw is composed of cellulose and hemicellulose that can be hydrolyzed to fermentable sugar by cellulolytic and hemicellulolytic enzymes then converted to L-lactic acid by Rhizopus oryzae. As most cellulose and hemicellulose present in lignocellulose biomass are not readily accessible for these enzyme, pretreatment is required to alter the structure of lignocellulose substrates. This research aimed to investigate the effect of lime pretreatment on rice straw bioconversion to L-lactic acid by Rhizopus oryzae AT3. Rice straw was pretreated with lime (Ca(OH2 at 85 °C for 16 hours. Unpretreated and pretreated rice straw were hydrolyzed using crude enzyme that produced by Trichoderma reesei Pk1J2. Enzyme production was carried out by solid state fermentation using rice straw and rice brand as substrate. Enzymatic hydrolysis was carried out in flasks. Each flask was added with unpretreated or pretreated rice straw, buffer citrate solution and crude enzyme then hydrolyzed for 0-96 hours. Hydrolysate was fermented by Rhizopus oryzae AT3 for 0-6 days by using adsorbed carrier solid-state fermentation method with polyurethane foam as inert support material. Lime pretreatment at 85 °C for 16 hour led to significant solubilisation of lignin and hemicellulose. It involved lignocellulose structure modified that enhance enzymatic hydrolysis and resulted higher reducing sugars than unpretreated rice straw. The high reducing sugars was not related to high lactic acid yields. Fermentation of pretreated rice straw hydrolysate by Rhizopus oryzae AT3 did not only produce L-lactic acid but also other compound. On the other hand, fermentation of unpretreated rice straw hydrolysate only produced L-lactic acid.   ABSTRAK Polimerisasi asam

  13. Bioconversion of petroleum hydrocarbons in soil using apple filter cake Bioconversão de hidrocarbonetos de petróleo no solo pelo uso de bagaço de maçã

    Directory of Open Access Journals (Sweden)

    M. Cecilia Medaura

    2008-09-01

    Full Text Available The aim of this study was to investigate the feasibility of using apple filter cake, a fruit-processing waste to enhance the bioremediation of petroleum contaminated soil. A rotating barrel system was used to study the bioconversion of the xenobiotic compound by natural occurring microbial population. The soil had been accidentally polluted with a total petroleum hydrocarbon concentration of 41,000 ppm. Although this global value was maintained during the process, microbial intervention was evidenced through transformation of the petroleum fractions. Thus, fractions that represent a risk for the environment (GRO, Gasoline Range Organics i.e., C6 to C10-12; DRO, Diesel Range Organics i.e., C8-12 to C24-26 and RRO, Residual Range Organics i.e., C25 to C35 were significantly reduced, from 2.95% to 1.39%. On the contrary, heavier weight fraction from C35 plus other organics increased in value from 1.15% to 3.00%. The noticeable diminution of low molecular weight hydrocarbons content and hence environmental risk by the process plus the improvement of the physical characteristics of the soil, are promising results with regard to future application at large scale.O objetivo deste estudo foi investigara viabilidade de aplicação de bagaço de maçã, um resíduo do processamento de frutas, para melhorar a biorremediação de solo contaminado com petróleo. Para estudar a bioconversão de compostos xenobióticos pela população microbiana naturalmente presente empregou-se um sistema de barril rotativo. O solo havia sido acidentalmente contaminado com um total de hidrocarbonetos de petróleo na concentração de 41.000 ppm. Embora esse valor tenha se mantido durante o processo, a intervenção microbiana ficou evidenciada através da transformação de frações do petróleo. Assim, as frações de risco para o meio ambiente (GRO, Gasoline Range Organics, i.e., C6 a C10-12; DRO, Diesel Ramge Organics, i.e. C8-12 a C24-26 e RRO, Residual Range Organics

  14. 油气藏埋存二氧化碳生物转化甲烷的机理和应用研究进展%Research Progress on the Mechanism and Potential Application of CH4 Bioconversion from CO2 in Oil and Gas Reservoirs

    Institute of Scientific and Technical Information of China (English)

    魏小芳; 罗一菁; 刘可禹; 帅燕华

    2011-01-01

    The bioconversion of CH4 from the stored CO2 is a biotechnological solution that the injected CO2 is metabolized by indigenous microbes in depleted oil or gas reservoirs to produce CH4 by CO2 bioreduction pathway. It is potential applied and promising technology due to its environmental friendship for CO2 storage and sequestration, renewable energy of biogas CH4, extended oil and gas reservoirs development period, and the potential profit for enhanced gas or oil recovery. The CO2 Capture & Storage project and microbial diversity of reservoirs offer the solution feasibility. Hydrogenotrophic mesophilic or thermophilic methanogens are known to be common inhabitants in slightly saline formation water in oil and gas reservoirs. The distribution of CO2/H2 methanongens of biogas reservoirs changes with diagenetic stages. It has been shown that CO2can be potentially bioconverted to CH4 in reservoirs under certain conditions. However, oil and gas reservoirs are complicated systems and the bioconversion is constrained by the relationships among the methanogens, fermentative bacteria and hydrogen-producing bacteria. The methanogen community structure and the co-metabolization and competition between the two communities of Sulfate Reduction Bacteria ( SRB) and methanogens may also impact the CO2 reduction. Compared to the discovered knowledge that CO2 bioreduction pathway is permissible, the process may be quite complicated to be realized in reservoirs. It is difficult to realize the CO2 bioreduction pathway without synthetic H2 supply. It is still a big challenge for both microbiologists and petroleum engineers to realize CH4 bioconversion from CO2 by parameters control in reservoirs. At present, the CO2 reduction research is at experimental stage in the laboratory, the breakthrough is to activate the suited reservoirs microorganism consortium to realize the CH4 bioconversion in right way, to probe the profitable CH4 bioconversion rate and production velocity. Though the

  15. Bioconversion of mixed solids waste to ethanol.

    Science.gov (United States)

    Nguyen, Q A; Keller, F A; Tucker, M P; Lombard, C K; Jenkins, B M; Yomogida, D E; Tiangco, V M

    1999-01-01

    A mixed solids waste (MSW) feedstock, comprising construction lumber waste (35% oven-dry basis), almond tree prunings (20%), wheat straw (20%), office waste paper (12.5%), and newsprint (12.5%), was converted to ethanol via dilute-acid pretreatment followed by enzymatic hydrolysis and yeast fermentation. The MSW was pretreated with dilute sulfuric acid (0.4% w/w) at 210 degrees C for 3 min in a 4-L steam explosion reactor, then washed with water to recover the solubilized hemicellulose. The digestibility of water-washed, pretreated MSW was 90% in batch enzymatic hydrolysis at 66 FPU/g cellulose. Using an enzyme-recycle bioreactor system, greater than 90% cellulose hydrolysis was achieved at a net enzyme loading of about 10 FPU/g cellulose. Enzyme recycling using membrane filtration and a fed-batch fermentation technique is a promising option for significantly reducing the cost of enzyme in cellulose hydrolysis. The hexose sugars were readily fermentable using a Saccharomyces cerevisiae yeast strain that was adapted to the hydrolysate. Solid residue after enzyme digestion was subjected to various furnace experiments designed to assess the fouling and slagging characteristics. Results of these analyses suggest the residue to be of a low to moderate slagging and fouling type if burned by itself.

  16. Bioconversion of Capsaicin by Aspergillus oryzae.

    Science.gov (United States)

    Lee, Minji; Cho, Jeong-Yong; Lee, Yu Geon; Lee, Hyoung Jae; Lim, Seong-Il; Park, So-Lim; Moon, Jae-Hak

    2015-07-08

    This study identified metabolites of capsaicin bioconverted by Aspergillus oryzae, which is generally used for mass production of gochujang prepared by fermenting red pepper powder in Korea. A. oryzae was incubated with capsaicin in potato dextrose broth. Capsaicin decreased depending on the incubation period, but new metabolites increased. Five capsaicin metabolites purified from the ethyl acetate fraction of the capsaicin culture were identified as N-vanillylcarbamoylbutyric acid, N-vanillyl-9-hydroxy-8-methyloctanamide, ω-hydroxycapsaicin, 8-methyl-N-vanillylcarbamoyl-6(E)-octenoic acid, and 2-methyl-N-vanillylcarbamoyl-6(Z)-octenoic acid by nuclear magnetic resonance (NMR) and mass spectrometry (MS). The capsaicin metabolites in gochujang were confirmed and quantitated by selective multiple reaction monitoring detection after liquid chromatography electrospray ionization MS using the isolated compounds as external standards. On the basis of the structures of the capsaicin metabolites, it is proposed that capsaicin metabolites were converted by A. oryzae by ω-hydroxylation, alcohol oxidation, hydrogenation, isomerization, and α- and/or β-oxidation.

  17. Inhibitory effect of acetic acid on bioconversion of xylose in xylitol by Candida guilliermondii in sugarcane bagasse hydrolysate Efeito inibitório do ácido acético na bioconversão de xilose em xilitol por Candida guilliermondii em hidrolisado de bagaço de cana

    Directory of Open Access Journals (Sweden)

    Débora D.V. Silva

    2004-09-01

    Full Text Available Sugarcane bagasse hydrolysate (initial acetic acid concentration = 3.5g/L, was used as a fermentation medium for conversion of xylose into xylitol by the yeast Candida guilliermondii FTI 20037. Acetic acid (2.0g/L was added to the medium at different times of fermentation, with the aim of evaluating its effects on the bioconversion process. The addition of acetic acid to the medium after 12h of fermentation resulted in the strongest inhibition of the yeast metabolism. In this case, the xylose consumption and cell growth were, respectively, 23.22 and 11.24% lower than when acid was added to the medium at the beginning of fermentation. As a consequence of the inhibitory effect, lower values of the xylitol yield (0.39g/g and productivity (0.22g/L.h were observed, corresponding to a reduction of 36 and 48%, respectively, in relation to the values obtained with the addition of acetic acid after other fermentation times. The results obtained allowed to conclude that, under the experimental conditions employed in this work, the inhibitory effect of acetic acid on the xylose-xylitol bioconversion depends on the fermentation time when this acid was added, and not only on its concentration in the medium.Hidrolisado de bagaço de cana-de-açúcar contendo uma concentração inicial de ácido acético de 3,5g/L foi utilizado como meio de fermentação para a bioconversão de xilose em xilitol pela levedura Candida guilliermondii FTI 20037. Ácido acético (2,0g/L foi adicionado ao meio em diferentes tempos de fermentação, com o objetivo de avaliar o efeito deste ácido neste bioprocesso. O maior efeito inibitório deste ácido na bioconversão de xilose em xilitol pela levedura ocorreu quando este foi adicionado ao meio após 12h de fermentação. Nesta condição observou-se uma redução de 23,22% e 11,24%, respectivamente, no consumo de xilose e no crescimento celular em relação à fermentação em que a adição deste ácido ocorreu no tempo inicial

  18. Bioconversion of coal derived synthesis gas to liquid fuels

    Science.gov (United States)

    Jain, M. K.; Worden, R. M.; Grethlein, A.

    1994-07-01

    The overall objective of the project is to develop an integrated two-stage fermentation process for conversion of coal-derived synthesis gas to a mixture of alcohols. This is achieved in two steps. In the first step, Butyribacterium methylotrophicum converts carbon monoxide (CO) to butyric and acetic acids. Subsequent fermentation of the acids by Clostridium acetobutylicum leads to the production of butanol and ethanol. The tasks for this quarter were: development/isolation of superior strains for fermentation of syngas; evaluation of bioreactor configuration for improved mass transfer of syngas; recovery of carbon and electrons from H2-CO2; initiation of pervaporation for recovery of solvents; and selection of solid support material for trickle-bed fermentation. Technical progress included the following: butyrate production was enhanced during H2/CO2 (50/50) batch fermentation; isolation of CO-utilizing anaerobic strains is in progress; pressure (15 psig) fermentation was evaluated as a means of increasing CO availability; polyurethane foam packing material was selected for trickle bed solid support; cell recycle fermentation on syngas operated for 3 months. Acetate was the primary product at pH 6.8; trickle bed and gas lift fermentor designs were modified after initial water testing; and pervaporation system was constructed (No alcohol selectivity was shown with the existing membranes during initial start-up).

  19. Bioconversion of energy by Spirulina maxima on continuous culture

    Energy Technology Data Exchange (ETDEWEB)

    Chaumont, D.; Gudin, C.; Delepine, R.; Asensi, A.

    1982-11-01

    The influence of the light intensity, photoperiod and residence time were studied on a continuous culture of Spirulina maxima. A maximum photosynthetic conversion yield of 13% on visible energy and a minimum quantic need of 23 photons per integrated CO/sub 2/ molecule were obtained in this way. By the application of continuous cultivation techniques a strain of Sprirulina developing on sea water was selected.

  20. Biotransformation and bioconversion of phenolic compounds obtainment: an overview.

    Science.gov (United States)

    Madeira Junior, Jose Valdo; Teixeira, Camilo Barroso; Macedo, Gabriela Alves

    2015-03-01

    Phenolic compounds have recently been recognized for their influence on human metabolism, acting in the prevention of some chronic diseases as well as proving to be important antioxidants in food. Nevertheless, the extraction and concentration processes are usually carried out by organic solvent extraction from natural sources and can generate some drawbacks like phenolic compound degradation, lengthy process times and low yields. As a solution, some eco-friendly technologies, including solid-state fermentation (SSF) or enzymatic-assisted reaction, have been proposed as alternative processes. This article reviews the extraction of phenolic compounds from agro-industrial co-products by solid-state fermentation, even as friendly enzyme-assisted extractions. It also discusses the characteristics of each bioprocess system and the variables that affect product formation, as well as the range of substrates, microorganisms and enzymes that can be useful for the production of bioactive phenolic compounds.

  1. Ensilage and bioconversion of grape pomace into fuel ethanol.

    Science.gov (United States)

    Zheng, Yi; Lee, Christopher; Yu, Chaowei; Cheng, Yu-Shen; Simmons, Christopher W; Zhang, Ruihong; Jenkins, Bryan M; VanderGheynst, Jean S

    2012-11-07

    Two types of grape pomace were ensiled with eight strains of lactic acid bacteria (LAB). Both fresh grape pomace (FrGP) and fermented grape pomace (FeGP) were preserved through alcoholic fermentation but not malolactic conversion. Water leaching prior to storage was used to reduce water-soluble carbohydrates and ethanol from FrGP and FeGP, respectively, to increase malolactic conversion. Leached FeGP had spoilage after 28 days of ensilage, whereas FrGP was preserved. Dilute acid pretreatment was examined for increasing the conversion of pomace to ethanol via Escherichia coli KO11 fermentation. Dilute acid pretreatment doubled the ethanol yield from FeGP, but it did not improve the ethanol yield from FrGP. The ethanol yields from raw pomace were nearly double the yields from the ensiled pomace. For this reason, the recovery of ethanol produced during winemaking from FeGP and ethanol produced during storage of FrGP is critical for the economical conversion of grape pomace to biofuel.

  2. Renewable biofuels bioconversion of lignocellulosic biomass by microbial community

    CERN Document Server

    Rana, Vandana

    2017-01-01

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

  3. Bioconversion of selenate in methanogenic anaerobic granular sludge.

    Science.gov (United States)

    Astratinei, Violeta; van Hullebusch, Eric; Lens, Piet

    2006-01-01

    The capacity of anaerobic granular sludge to remove selenate from contaminated wastewater was investigated. The potential of different types of granular sludge to remove selenate from the liquid phase was compared to that of suspended sludge and contaminated soil and sediment samples. The selenate removal rates ranged from 400 to 1500 microg g VSS(-1) h(-1), depending on the source of biomass, electron donor, and the initial selenate concentration. The granular structure protects the microorganisms when exposed to high selenate concentrations (0.1 to 1 mM). Anaerobic granular sludge "Eerbeek," originating from a UASB reactor treating paper mill wastewater, removed about 90, 50, and 36% of 0.1, 0.5, and 1 mM of Se, respectively, from the liquid phase when incubated with 20 mM lactate at 30 degrees C and pH 7.5. Selenite, elemental Se (Se(o)), and metal selenide precipitates were the conversion products. Enrichments from the anaerobic granular sludge "Eerbeek" were able to convert 90% of the 10-mM selenate to Se(o) at a rate of 1505 microg Se(VI) g cells(-1) h(-1), a specific growth rate of 0.0125 g cells h(-1), and a yield of 0.083 g cells mg Se(-1). Both microbial metabolic processes (e.g dissimilatory reduction) as well as microbially mediated physicochemical mechanisms (adsorption and precipitation) contribute to the removal of selenate from the Se-containing medium.

  4. Bioconversion and combinatorial biosynthesis of selected terpenoids and lignans

    NARCIS (Netherlands)

    Julsing, Mattijs Kamiel

    2006-01-01

    Een aanzienlijk deel van de huidige geneesmiddelen is oorspronkelijk een natuurstof of een afgeleide hiervan. Hoewel eenvoudige verbindingen chemisch kunnen worden nagemaakt, is voor complexe verbindingen de chemische synthese lastig en economisch niet rendabel, waardoor we afhankelijk zijn van de p

  5. Bioconversion of crude glycerol feedstocks into ethanol by Pachysolen tannophilus

    DEFF Research Database (Denmark)

    Liu, Xiaoying; Jensen, Peter Ruhdal; Workman, Mhairi

    2012-01-01

    Glycerol, the by-product of biodiesel production, is considered as a waste by biodiesel producers. This study demonstrated the potential of utilising the glycerol surplus through conversion to ethanol by the yeast Pachysolen tannophilus (CBS4044). This study demonstrates a robust bioprocess which...... was not sensitive to the batch variability in crude glycerol dependent on raw materials used for biodiesel production. The oxygen transfer rate (OTR) was a key factor for ethanol production, with lower OTR having a positive effect on ethanol production. The highest ethanol production was 17.5 g/L on 5% (v/v) crude...... glycerol, corresponding to 56% of the theoretical yield. A staged batch process achieved 28.1 g/L ethanol, the maximum achieved so far for conversion of glycerol to ethanol in a microbial bioprocess. The fermentation physiology has been investigated as a means to designing a competitive bioethanol...

  6. The lignan macromolecule from flaxseed : structure and bioconversion of lignans

    NARCIS (Netherlands)

    Struijs, K.

    2008-01-01

    Flaxseeds are known already for a long time for their positive health effects. The high content of dietary fiber, the advantageous fatty acid composition and the lignans are held responsible for this. Lignans are compounds, which have a similar structure as human estradiol. As a result of that, they

  7. Bioconversion of oleuropein to hydroxytyrosol by lactic acid bacteria.

    Science.gov (United States)

    Santos, M M; Piccirillo, C; Castro, P M L; Kalogerakis, N; Pintado, M E

    2012-06-01

    The aim of this work is to study the conversion of oleuropein-a polyphenol present in olives and olive oil by-products-into hydroxytyrosol, a polyphenol with antioxidant and antibacterial properties. The hydrolysis reaction is performed by lactic acid bacteria. Six bacterial strains (Lactobacillus plantarum 6907, Lactobacillus paracasei 9192, Lactobacillus casei, Bifidobacterium lactis BO, Enterococcus faecium 32, Lactobacillus LAFTI 10) were tested under aerobic and anaerobic conditions. The oleuropein degradation and hydroxytyrosol formation were monitored by HPLC. Results showed that oleuropein could be successfully converted into hydroxytyrosol. The most effective strain was Lactobacillus plantarum 6907, with a reaction yield of hydroxytyrosol of about 30 %. Different reaction mechanisms were observed for different microorganisms; a different yield was observed for Lactobacillus paracasei 9192 under aerobic or anaerobic conditions and an intermediate metabolite (oleuropein aglycone) was detected for Lactobacillus paracasei 9192 and Lactobacillus plantarum 6907 only. This study could have significant applications, as this reaction can be used to increase the value of olive oil by-products and/or to improve the taste of unripe olives.

  8. Bioconversion of Selenate in Methanogenic Anaerobic Granular Sludge

    NARCIS (Netherlands)

    Astratinei, V.; Hullebusch, van E.D.; Lens, P.N.L.

    2006-01-01

    The capacity of anaerobic granular sludge to remove selenate from contaminated wastewater was investigated. The potential of different types of granular sludge to remove selenate from the liquid phase was compared to that of suspended sludge and contaminated soil and sediment samples. The selenate r

  9. Compounds inhibiting the bioconversion of hydrothermally pretreated lignocellulose.

    Science.gov (United States)

    Ko, Ja Kyong; Um, Youngsoon; Park, Yong-Cheol; Seo, Jin-Ho; Kim, Kyoung Heon

    2015-05-01

    Hydrothermal pretreatment using liquid hot water, steam explosion, or dilute acids enhances the enzymatic digestibility of cellulose by altering the chemical and/or physical structures of lignocellulosic biomass. However, compounds that inhibit both enzymes and microbial activity, including lignin-derived phenolics, soluble sugars, furan aldehydes, and weak acids, are also generated during pretreatment. Insoluble lignin, which predominantly remains within the pretreated solids, also acts as a significant inhibitor of cellulases during hydrolysis of cellulose. Exposed lignin, which is modified to be more recalcitrant to enzymes during pretreatment, adsorbs cellulase nonproductively and reduces the availability of active cellulase for hydrolysis of cellulose. Similarly, lignin-derived phenolics inhibit or deactivate cellulase and β-glucosidase via irreversible binding or precipitation. Meanwhile, the performance of fermenting microorganisms is negatively affected by phenolics, sugar degradation products, and weak acids. This review describes the current knowledge regarding the contributions of inhibitors present in whole pretreatment slurries to the enzymatic hydrolysis of cellulose and fermentation. Furthermore, we discuss various biological strategies to mitigate the effects of these inhibitors on enzymatic and microbial activity to improve the lignocellulose-to-biofuel process robustness. While the inhibitory effect of lignin on enzymes can be relieved through the use of lignin blockers and by genetically engineering the structure of lignin or of cellulase itself, soluble inhibitors, including phenolics, furan aldehydes, and weak acids, can be detoxified by microorganisms or laccase.

  10. Bioconversion of corncob to hydrogen using anaerobic mixed microflora

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Chunmei [Department of Chemistry, Zhengzhou University, Daxue Road, Zhengzhou 450052 (China); Biotechnology Department, Zhengzhou College of Animal Husbandry Engineering, Zhengzhou 450011 (China); Zhang, Shufang; Fan, Yaoting; Hou, Hongwei [Department of Chemistry, Zhengzhou University, Daxue Road, Zhengzhou 450052 (China)

    2010-04-15

    Biohydrogen production from corncob using natural anaerobic microflora was reported for the first time. The optimum pretreatment condition for the corncob was determined to be 100 C, 30 min, and 1% HCl (w/w). The maximum hydrogen yield of 107.9 ml/g-TVS and hydrogen production rate of 4.20 ml/g-TVS h{sup -1} was obtained under the condition of 10 g/l substrate concentration and initial pH 8.0. Butyrate and acetate were the dominant metabolic by-products of hydrogen fermentation. Chemical composition analysis, Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) were used to study the mechanism of degrading corncob for hydrogen production. The amorphous domains of cellulose and hemicellulose were hydrolyzed into fermentable saccharides through acid pretreatment and the microorganisms had a devastating effect on the crystallinity of the cellulose. The hydrogen yield from pretreated corncob was much higher than from raw corncob. Therefore, the acid pretreatment played a crucial role on hydrogen production from corncob. (author)

  11. Bioconversion of soy isoflavones daidzin and daidzein by Bifidobacterium strains.

    Science.gov (United States)

    Raimondi, Stefano; Roncaglia, Lucia; De Lucia, Marzia; Amaretti, Alberto; Leonardi, Alan; Pagnoni, Ugo Maria; Rossi, Maddalena

    2009-01-01

    Twenty-two strains of Bifidobacterium, representative of eight major species of human origin, were screened for their ability to transform the isoflavones daidzin and daidzein. Most of the strains released the aglycone from daidzin and 12 gave yields higher than 90%. The kinetics of growth, daidzin consumption, and daidzein production indicated that the hydrolytic activity occurred during the growth. The supernatant of the majority of the strains did not release the aglycone from daidzin, suggesting that cell-associated beta-glucosidases (beta-Glu) are mainly responsible for the metabolism of soybean glyco-conjugates. Cell-associated beta-Glu was mainly intracellular and significantly varied among the species and the strains. The lack of beta-Glu was correlated with the inability to hydrolyze daidzin. Although S-equol production by anaerobic intestinal bacteria has been established, information on S-equol-producing bifidobacteria is contradictory. In this study, 22 bifidobacteria failed to transform daidzein into reduced metabolites under all the experimental conditions, excluding any role in the reductive pathway of daidzein toward the production of S-equol. These results suggest that selected probiotic strains of Bifidobacterium can be used to speed up the release of daidzein, improving its bioavailability for absorption by colonic mucosa and/or biotransformation to S-equol by other intestinal microorganisms.

  12. Bioconversion of heavy crude oils: A basis for new technology

    Energy Technology Data Exchange (ETDEWEB)

    Premuzic, E.T.; Lin, M.S.; Lian, H.

    1995-10-01

    Systematic studies of chemical mechanisms by which selected microorganisms react with crude oils have led to the identification of biochemical markers characteristic of the interactions of microbes with oils. These biomarkers belong to several groups of natural products ranging from saturate and polyaromatic hydrocarbons containing heterocyclics to organometallic compounds. The biochemical conversions of oils can be monitored by these chemical markers, which are particularly useful in the optimization of biochemical processing, cost efficiency, and engineering studies. Recent results from these studies will be discussed in terms of biochemical technology for the processing of crude oils.

  13. Bioconversion of lignin model compounds with oleaginous Rhodococci

    Energy Technology Data Exchange (ETDEWEB)

    Kosa, Matyas; Ragauskas, Arthur J. [Georgia Institute of Technology, Atlanta, GA (United States). Dept. of Chemistry and Biochemistry

    2012-01-15

    Although economically efficient biomass conversion depends on the utilization of the complete cell wall (biorefinery concept), including polysaccharides and lignin, current biofuels research concentrate mostly on cellulose conversion, while lignin is viewed as a side-product that is used primarily as a thermal resource. Microbiological conversion of lignin is almost exclusive to fungi, usually resulting in increased cell mass and lignolytic enzymes. Some bacteria can also degrade lignin-related compounds using the {beta}-ketoadipate pathway; for example, Rhodococcus opacus DSM 1069 can degrade coniferyl alcohol and grow on it as sole carbon source. Moreover, this strain belongs to the actinomycetes group that is also known for oleaginous species with lipid accumulation over 20%. Present work shows that R. opacus DSM 1069 and PD630 strains under nitrogen limiting conditions can convert lignin model compounds into triacylglycerols, also known as neutral lipids. 4-Hydroxybenzoic and vanillic acid lignin model compounds were used as sole carbon sources, and after brief adaptation periods, the cells not only began growing but accumulated lipids to the level of oleaginicity. These lipids were extracted for transesterification and analysis of fatty acid methyl esters showed good composition for biodiesel applications with no aromatics. Furthermore, the two strains showed distinct substrate metabolism and product profiles. (orig.)

  14. Bioconversion of Agricultural Waste to Ethanol by SSF Using Recombinant Cellulase from Clostridium thermocellum

    Directory of Open Access Journals (Sweden)

    Ruchi Mutreja

    2011-01-01

    Full Text Available The effect of different pretreatment methods, temperature, and enzyme concentration on ethanol production from 8 lignocellulosic agrowaste by simultaneous saccharification and fermentation (SSF using recombinant cellulase and Saccharomyces cerevisiae were studied. Recombinant cellulase was isolated from E. coli BL21 cells transformed with CtLic26A-Cel5-CBM11 full-length gene from Clostridium thermocellum and produced in both batch and fed-batch processes. The maximum cell OD and specific activity in batch mode were 1.6 and 1.91 U/mg, respectively, whereas in the fed-batch mode, maximum cell OD and specific activity were 3.8 and 3.5 U/mg, respectively, displaying a 2-fold increase. Eight substrates, Syzygium cumini (jamun, Azadirachta indica (neem, Saracens indica (asoka, bambusa dendrocalmus (bamboo, Populas nigra (poplar, Achnatherum hymenoides (wild grass, Eucalyptus marginata (eucalyptus, and Mangifera indica (mango, were subjected to SSF. Of three pretreatments, acid, alkali, and steam explosion, acid pretreatment Syzygium cumini (Jamun at 30°C gave maximum ethanol yield of 1.42 g/L.

  15. Integrated cellulosic enzymes hydrolysis and fermentative advanced yeast bioconversion solution ready for biomass biorefineries

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Manoj [DSM Innovation, Inc., San Francisco, CA (United States)

    2011-05-04

    These are slides from this conference. Lignocellulosic biomass is the most abundant, least expensive renewable natural biological resource for the production of biobased products and bioenergy is important for the sustainable development of human civilization in 21st century. For making the fermentable sugars from lignocellulosic biomass, a reduction in cellulase production cost, an improvement in cellulase performance, and an increase in sugar yields are all vital to reduce the processing costs of biorefineries. Improvements in specific cellulase activities for non-complexed cellulase mixtures can be implemented through cellulase engineering based on rational design or directed evolution for each cellulase component enzyme, as well as on the reconstitution of cellulase components. In this paper, we will provide DSM's efforts in cellulase research and developments and focus on limitations. Cellulase improvement strategies based on directed evolution using screening on relevant substrates, screening for higher thermal tolerance based on activity screening approaches such as continuous culture using insoluble cellulosic substrates as a powerful selection tool for enriching beneficial cellulase mutants from the large library. We will illustrate why and how thermostable cellulases are vital for economic delivery of bioproducts from cellulosic biomass using biochemical conversion approach.

  16. Effect of pelleting on the recalcitrance and bioconversion of dilute-acid pretreated corn stover

    Energy Technology Data Exchange (ETDEWEB)

    Allison E Ray; Amber Hoover; Gary Gresham

    2012-07-01

    Background: Knowledge regarding the performance of densified biomass in biochemical processes is limited. The effects of densification on biochemical conversion are explored here. Methods: Pelleted corn stover samples were generated from bales that were milled to 6.35 mm. Low-solids acid pretreatment and simultaneous saccharification and fermentation were performed to evaluate pretreatment efficacy and ethanol yields achieved for pelleted and ground stover (6.35 mm and 2 mm) samples. Both pelleted and 6.35-mm ground stover were evaluated using a ZipperClave® reactor under high-solids, process-relevant conditions for multiple pretreatment severities (Ro), followed by enzymatic hydrolysis of the washed, pretreated solids. Results: Monomeric xylose yields were significantly higher for pellets (approximately 60%) than for ground formats (approximately 38%). Pellets achieved approximately 84% of theoretical ethanol yield (TEY); ground stover formats had similar profiles, reaching approximately 68% TEY. Pelleting corn stover was not detrimental to pretreatment efficacy for both low- and high-solids conditions, and even enhanced ethanol yields.

  17. Bioconversion of plant biomass to ethanol. Annual report and revised research plan, January 1977--January 1978

    Energy Technology Data Exchange (ETDEWEB)

    Brooks, R.E.; Bellamy, W.D.; Su, T.M.

    1978-03-23

    The objective of this research is to demonstrate on a laboratory scale the technical feasibility of the direct microbial conversion of pretreated wood to ethanol. During the first year of this contract, we investigated the feasibility of biologically delignifying wood with C. pruinosum and directly fermenting the pretreated wood to ethanol with a mixed culture. Bench-top fermentations of a thermophilic bacillus growing on glucose and of a mixed culture of thermophilic sporocytophaga (US) and a thermophilic bacillus growing on microcrystalline and amorphous cellulose were evaluated for growth and ethanol production. In the mixed culture fermentation of amorphous and microcrystalline cellulose, the specific rate of substrate depletion was calculated to be 0.087 hr/sup -1/ and 0.0346 hr/sup -1/, respectively. However, defining the growth requirements of C. pruinosum and sporocytophaga (US) proved more difficult than originally anticipated. In order to achieve the program objectives within the contract period, a revised research plan was developed based upon chemical pretreatment and the direct fermentation of pretreated hardwood to ethanol. In place of the biological delignification pretreatment step, we have substituted a chemically supplemented steam pretreatment step to partially delignify wood and to enhance its accessibility to microbial utilization. Clostridium thermocellum, which ferments cellulose directly to ethanol and acetic acid, has replaced the mixed culture fermentation stage for ethanol production. Research on the production of ethanol from xylose by the thermophilic bacillus ZB-B2 is retained as one means of utilizing the hemicellulose fraction of hardwood. Work on the genetic improvement of the ethanol yields of both cultures by suppressing acetic acid production is also retained. The rationale, experimental approach, and economic considerations of this revised research plan are also presented.

  18. Bioconversion of industrial solid waste--cassava bagasse for pullulan production in solid state fermentation.

    Science.gov (United States)

    Sugumaran, K R; Jothi, P; Ponnusami, V

    2014-01-01

    The purpose of the work was to produce commercially important pullulan using industrial solid waste namely cassava bagasse in solid state fermentation and minimize the solid waste disposal problem. First, influence of initial pH on cell morphology and pullulan yield was studied. Effect of various factors like fermentation time, moisture ratio, nitrogen sources and particle size on pullulan yield was investigated. Various supplementary carbon sources (3%, w/w) namely glucose, sucrose, fructose, maltose, mannose and xylose with cassava bagasse was also studied to improve the pullulan yield. After screening the suitable supplement, effect of supplement concentration on pullulan production was investigated. The pullulan from cassava bagasse was characterized by FTIR, (1)H-NMR and (13)C-NMR. Molecular weight of pullulan from cassava bagasse was determined by gel permeation chromatography. Thus, cassava bagasse emerged to be a cheap and novel substrate for pullulan production.

  19. Bioconversion of sugar cane crop residues with white-rot fungiPleurotus sp.

    Science.gov (United States)

    Ortega, G M; Martínez, E O; Betancourt, D; González, A E; Otero, M A

    1992-07-01

    Four mushroom strains ofPleurotus spp. were cultivated on sugar cane crop residues for 30 days at 26°C. Biochemical changes affected the substrate as a result of fungal growth, in terms of nitrogen, lignin, cellulose and hemicellulose contents. All strains showed a strong ligninolytic activity together with variable cellulolytic and xylanolytic action.Pleurotus sajor-caju attacked lignin and cellulose at the same rate, showing a degradation of 47% and 55%, respectively. A better balance was shown by theP. ostreatus-P. pulmonarius hybrid, which exhibited the poorest cellulolytic action (39%) and the highest ligninolytic activity (67%). The average composition of mushroom fruit bodies, in terms of nitrogen, carbohydrates, fats and amino acid profiles, was determined. Crude protein and total carbohydrate varied from 23% to 33% and 36% to 68% of dry matter, respectively. Fat ranged from 3.3% to 4.7% and amino acid content from 12.2% to 22.2%. Slight evidence for a nitrogen fixing capability was encountered in the substrate to fruit body balance.

  20. Composting and vermicomposting experiences in the treatment and bioconversion of asphaltens from the Prestige oil spill.

    Science.gov (United States)

    Martín-Gil, Jesús; Navas-Gracia, Luís Manuel; Gómez-Sobrino, Ernesto; Correa-Guimaraes, Adriana; Hernández-Navarro, Salvador; Sánchez-Báscones, Mercedes; del Carmen Ramos-Sánchez, María

    2008-04-01

    This work illustrates the effectiveness of composting and vermicomposting in degrading fuel-in-water emulsions from oil spills (chapapote), and the isolation of potentially useful microorganisms for its biodegradation. Firstly, an alternative to the biodegradation of asphaltens from the Prestige oil spill (still present in some chapapote rafts in the Cantabrian coast) by means of the application of composting techniques to a microbial partnership acclimated to fuel-oil is offered. Our aim is that, after a relatively short period of time, the microorganisms can obtain its source of carbon and energy from asphaltens. The addition of metabolic co-substrates, like cow bed and potato peelings, allows the fragmentation of complex compounds into smaller structures, susceptible to further degradation. Afterwards, a maturation of the compost by means of a treatment with earthworms (Eisenia foetida) is necessary. Thus, through the vermicomposting it will be possible to obtain a valued product, useful in the processes of ground amendment, with little presence of asphaltens and occluded polycyclic aromatic hydrocarbons, rich in humus, and with an important bacterial flora of Bacillus genera, so that it can be typical of co-activators and accelerating products in composting processes. Along with this article, we show some parameters that control the evolution of the compost products (evolved gases, acidity, temperature and humidity); the chemical and microbiological analytical results; and the germination assays of vermicomposting. Results reveal that by using microorganisms living in either earthworm intestines (Stenotrophomonas maltophilia) or vermiculture substrates (Scedosporium apiospermium), it is possible to degrade and to eliminate the polycyclic asphaltens into CO(2) and H(2)O, helped by evaporation, dissolution and/or photo-oxidation processes. The obtained end product has contents of interesting vegetal nutrients and, mainly, it displays very high germination indices.

  1. Process development studies of the bioconversion of cellulose and production of ethanol. Semi annual report

    Energy Technology Data Exchange (ETDEWEB)

    Wilke, C.R.; Blanch, H.W.

    1981-04-01

    Progress in the following process development studio is reported: economic evaluation of hydrolysis and ethanol fermentation schemes, economic evaluation of alternative fermentation processes, raw materials evaluation, and evaluation of pretreatment process. Microbiological and enzymatic studies reported are: production of cellulase enzyme from high yielding mutants, hydrolysis reactor development, xylose fermentation, and xylanese production. Fermentation and separation processes include: process development studies on vacuum fermentation and distillation, evaluation of low energy separations processes, large scale hollow fiber reactor development. (MHR)

  2. Optimization of H2SO4-catalyzed hydrothermal pretreatment of rapeseed straw for bioconversion to ethanol

    DEFF Research Database (Denmark)

    Xuebin, Lu; Zhang, Y.; Angelidaki, Irini

    2009-01-01

    A central composite design of response surface method was used to optimize H2SO4-catalyzed hydrothermal pretreatment of rapeseed straw, in respect to acid concentration (0.5-2%), treatment time (5-20 min) and solid content (10-20%) at 180 degrees C. Enzymatic hydrolysis and fermentation were also...

  3. Integrated cellulosic enzymes hydrolysis and fermentative advanced yeast bioconversion solution ready for biomass biorefineries

    Energy Technology Data Exchange (ETDEWEB)

    Manoj Kumar, PhD

    2011-05-04

    Lignocellulosic biomass is the most abundant, least expensive renewable natural biological resource for the production of biobased products and bioenergy is important for the sustainable development of human civilization in 21st century. For making the fermentable sugars from lignocellulosic biomass, a reduction in cellulase production cost, an improvement in cellulase performance, and an increase in sugar yields are all vital to reduce the processing costs of biorefineries. Improvements in specific cellulase activities for non-complexed cellulase mixtures can be implemented through cellulase engineering based on rational design or directed evolution for each cellulase component enzyme, as well as on the reconstitution of cellulase components. In this paper, we will provide DSM's efforts in cellulase research and developments and focus on limitations. Cellulase improvement strategies based on directed evolution using screening on relevant substrates, screening for higher thermal tolerance based on activity screening approaches such as continuous culture using insoluble cellulosic substrates as a powerful selection tool for enriching beneficial cellulase mutants from the large library. We will illustrate why and how thermostable cellulases are vital for economic delivery of bioproducts from cellulosic biomass using biochemical conversion approach.

  4. Bioconversion of apigenin-7-O-β-glucoside in aqueous two-phase system

    OpenAIRE

    Ilić Sanja M.; Đaković Sanja D.; Cvejić Jelena H.; Antov Mirjana G.; Zeković Zoran P.

    2005-01-01

    The study is concerned with the conversion of apigenin-7-O-β-glucoside into apigenin in polyethylene glycol 6000 / dextran 20000 aqueous two-phase system by β-glucosidase. Apigenin was separated from apigenin-7-O-β-glucoside and β-glucosidase by their partition into opposite phases. In 14% PEG / 22.5% DEX aqueous two-phase system obtained yield of apigenin in top phase was 108%.

  5. Bioconversion of biodiesel refinery waste in the bioemulsifier by Trichosporon mycotoxinivorans CLA2

    Directory of Open Access Journals (Sweden)

    de Souza Monteiro Andrea

    2012-05-01

    Full Text Available Abstract Background The microbial bioemulsifiers was surface active compounds, are more effective in stabilizing oil-in-water emulsions. The yeasts have been isolated to produce bioemulsifiers from vegetable oils and industrial wastes. Results Trichosporon mycotoxinivorans CLA2 is bioemulsifier-producing yeast strain isolated from effluents of the dairy industry, with ability to emulsify different hydrophobic substrates. Bioemulsifier production (mg/L and the emulsifying activity (E24 of this strain were optimized by response surface methodology using mineral minimal medium containing refinery waste as the carbon source, which consisted of diatomaceous earth impregnated with esters from filters used in biodiesel purification. The highest bioemulsifier production occurred in mineral minimal medium containing 75 g/L biodiesel residue and 5 g/L ammonium sulfate. The highest emulsifying activity was obtained in medium containing 58 g/L biodiesel refinery residue and 4.6 g/L ammonium sulfate, and under these conditions, the model estimated an emulsifying activity of 85%. Gas chromatography and mass spectrometry analysis suggested a bioemulsifier molecule consisting of monosaccharides, predominantly xylose and mannose, and a long chain aliphatic groups composed of octadecanoic acid and hexadecanoic acid at concentrations of 48.01% and 43.16%, respectively. The carbohydrate composition as determined by GC-MS of their alditol acetate derivatives showed a larger ratio of xylose (49.27%, mannose (39.91%, and glucose (10.81%. 1 H NMR spectra confirmed by COSY suggested high molecular weight, polymeric pattern, presence of monosaccharide’s and long chain aliphatic groups in the bioemulsifier molecule. Conclusions The biodiesel residue is an economical substrate, therefore seems to be very promising for the low-cost production of active emulsifiers in the emulsification of aromatics, aliphatic hydrocarbons, and kerosene.

  6. A review on bioconversion of lignocellulosic biomass to H2: Key challenges and new insights.

    Science.gov (United States)

    Ren, Nan-Qi; Zhao, Lei; Chen, Chuan; Guo, Wan-Qian; Cao, Guang-Li

    2016-09-01

    With the increasing energy crisis and rising concern over climate change, the development of clean alternative energy sources is of great importance. Biohydrogen produced from lignocellulosic biomass is a promising candidate, because of its positives such as readily available, no harmful emissions, environment friendly, efficient, and renewable. However, obstacles still exist to enable the commercialization of biological hydrogen production from lignocellulosic biomass. Thus the objective of this work is to provide update information about the recent progress on lignocellulosic hydrogen conversion via dark fermentation. In this review, the most important technologies associated with lignocellulosic hydrogen fermentation were covered. Firstly, pretreatment methods for better utilization of lignocellulosic biomass are presented, at the same time, hydrolysis methods assisting to achieve efficient hydrogen fermentation were discussed. Afterwards, issues related to bioprocesses for hydrogen production purposes were presented. Additionally, the paper gave challenges and new insights of lignocellulosic biohydrogen production.

  7. Bioconversion of volatile fatty acids derived from waste activated sludge into lipids by Cryptococcus curvatus.

    Science.gov (United States)

    Liu, Jia; Liu, Jia-Nan; Yuan, Ming; Shen, Zi-Heng; Peng, Kai-Ming; Lu, Li-Jun; Huang, Xiang-Feng

    2016-07-01

    Pure volatile fatty acid (VFA) solution derived from waste activated sludge (WAS) was used to produce microbial lipids as culture medium in this study, which aimed to realize the resource recovery of WAS and provide low-cost feedstock for biodiesel production simultaneously. Cryptococcus curvatus was selected among three oleaginous yeast to produce lipids with VFAs derived from WAS. In batch cultivation, lipid contents increased from 10.2% to 16.8% when carbon to nitrogen ratio increased from about 3.5 to 165 after removal of ammonia nitrogen by struvite precipitation. The lipid content further increased to 39.6% and the biomass increased from 1.56g/L to 4.53g/L after cultivation for five cycles using sequencing batch culture (SBC) strategy. The lipids produced from WAS-derived VFA solution contained nearly 50% of monounsaturated fatty acids, including palmitic acid, heptadecanoic acid, ginkgolic acid, stearic acid, oleic acid, and linoleic acid, which showed the adequacy of biodiesel production.

  8. Bioconversion of potatoes residues or surplus potatoes to ethanol under non axenic conditions [abstract

    Directory of Open Access Journals (Sweden)

    Lamaudière, S.

    2010-01-01

    Full Text Available Biofuels can offer an alternative to fossil fuels in the context of climate change and fossil reserves depletion. With 3 million tons of potatoes produced in 2007 and a high yield per hectare of 47 tons, Belgium is the 19th largest producer in the world. The residual and surplus potatoes could be used to produce bioethanol by fermentation. We examined the feasibility of a simple ethanol fermentation process under non axenic conditions. The substrate was pretreated with commercial amylases or by adding as low as 10% FM (Fresh Matter barley malt. It was then fermented with Saccharomyces cerevisiae. Ethanol and volatile fatty acids were analyzed by GC-FID and soluble sugars were analyzed with the Anthrone method. Starch from potatoes was hydrolyzed to soluble sugars. Hydrolysis seems to continue with 10% FM of barley malt after 48 h while the hydrolysis stopped or decelerated with commercial enzymes. With 10% FM of malt, 3 h of hydrolysis and 7 days of fermentation, an ethanol concentration of 42 g.l-1 was obtained and the conversion yield was 139 gethanol.kg-1 DM. The fermentation conversion yield of soluble sugars to ethanol was > 82% and the endogenous competition was limited. However, starch hydrolyzing seems to be a limiting step under the conditions tested. Commercial enzymes did not provide better results under the same conditions.

  9. Maximization of bioconversion of castor oil into ricinoleic acid by response surface methodology.

    Science.gov (United States)

    Goswami, Debajyoti; Sen, Ramkrishna; Basu, Jayanta Kumar; De, Sirshendu

    2009-09-01

    In this study, response surface methodology was applied to optimize process variables like temperature, pH, enzyme concentration (mg/g oil), and buffer concentration (g/g oil) for hydrolysis of castor oil using Candida rugosa lipase. A 2(4) full factorial central composite design was used to develop the quadratic model that was subsequently optimized and the optimal conditions were as follows: temperature 40 degrees C, pH 7.72, enzyme concentration 5.28 mg/g oil, buffer concentration 1g/g oil and there was 65.5% conversion in 6 h. These predicted optimal conditions agreed well with the experimental results. This is the first report on the application of response surface methodology in castor oil hydrolysis using C. rugosa lipase with higher percentage conversion in 6 h.

  10. Bioconversion of glycerol for bioethanol production using isolated Escherichia coli SS1

    Directory of Open Access Journals (Sweden)

    Sheril Norliana Suhaimi

    2012-06-01

    Full Text Available Bioconverting glycerol into various valuable products is one of glycerol's promising applications due to its high availability at low cost and the existence of many glycerol-utilizing microorganisms. Bioethanol and biohydrogen, which are types of renewable fuels, are two examples of bioconverted products. The objectives of this study were to evaluate ethanol production from different media by local microorganism isolates and compare the ethanol fermentation profile of the selected strains to use of glucose or glycerol as sole carbon sources. The ethanol fermentations by six isolates were evaluated after a preliminary screening process. Strain named SS1 produced the highest ethanol yield of 1.0 mol: 1.0 mol glycerol and was identified as Escherichia coli SS1 Also, this isolated strain showed a higher affinity to glycerol than glucose for bioethanol production.

  11. Bioconversion of paper mill sludge to bioethanol in the presence of accelerants or hydrogen peroxide pretreatment.

    Science.gov (United States)

    Gurram, Raghu Nandan; Al-Shannag, Mohammad; Lecher, Nicholas Joshua; Duncan, Shona M; Singsaas, Eric Lawrence; Alkasrawi, Malek

    2015-09-01

    In this study we investigated the technical feasibility of convert paper mill sludge into fuel ethanol. This involved the removal of mineral fillers by using either chemical pretreatment or mechanical fractionation to determine their effects on cellulose hydrolysis and fermentation to ethanol. In addition, we studied the effect of cationic polyelectrolyte (as accelerant) addition and hydrogen peroxide pretreatment on enzymatic hydrolysis and fermentation. We present results showing that removing the fillers content (ash and calcium carbonate) from the paper mill sludge increases the enzymatic hydrolysis performance dramatically with higher cellulose conversion at faster rates. The addition of accelerant and hydrogen peroxide pretreatment further improved the hydrolysis yields by 16% and 25% (g glucose / g cellulose), respectively with the de-ashed sludge. The fermentation process of produced sugars achieved up to 95% of the maximum theoretical ethanol yield and higher ethanol productivities within 9h of fermentation.

  12. Bioconversion of Mono- and Sesquiterpenoids by Recombinant Human Cytochrome P450 Monooxygenases

    NARCIS (Netherlands)

    Julsing, Mattijs K.; Fichera, Mario A.; Malz, Frank; Ebbelaar, Monique; Bos, Rein; Woerdenbag, Herman J.; Quax, Wim J.; Kayser, Oliver

    2008-01-01

    Cytochrome P450 monooxygenases play an important role in the biosynthesis and metabolism of terpenoids. We explored the potential of recombinant human liver cytochrome P450 monooxygenases CYP1A2, CYP2C9, and CYP3A4, heterologously expressed in Escherichia coli, to convert mono- and sesquiterpenoids

  13. Bioconversion from crude glycerin by Xanthomonas campestris 2103: xanthan production and characterization

    Directory of Open Access Journals (Sweden)

    L. V. Brandão

    2013-12-01

    Full Text Available The production and rheological properties of xanthan gum from crude glycerin fermentation, a primary by-product of the biodiesel industry with environmental and health risks, were evaluated. Batch fermentations (28 °C/250 rpm /120 h were carried out using crude glycerin, 0.01% urea and 0.1% KH2PO4, (% w/v, and compared to a sucrose control under the same operational conditions, using Xanthomonas campestris strain 2103 isolate from Brazil. Its maximal production by crude glycerin fermentation was 7.23±0.1 g·L-1 at 120 h, with an apparent viscosity of 642.57 mPa·s, (2 % w/v, 25 °C, 25 s-1, 70% and 30% higher than from sucrose fermentation, respectively. Its molecular weight varied from 28.2 to 36.2×10(6 Da. The Ostwald-de-Waele model parameters (K and n indicated a pseudoplastic behavior at all concentrations (0.5 to 2.0 %, w/v and temperatures (25-85 °C, while its consistency index indicated promising rheological properties for drilling fluid applications. Therefore, crude glycerin has potential as a cost-effective and alternative substrate for non-food grade xanthan production.

  14. Production of bio-energy from low-value biomass by bioconversion

    Institute of Scientific and Technical Information of China (English)

    Tan Tianwei

    2014-01-01

    Since 1993,China has become a net importer of energy from a net exporter. The total energy con-sumption has been greater than the total supply,and the external dependence of the energy demand increases rapidly. China’s crude oil import volume and imports amount reached 253.78 million tons and 196.664 billion US dollars in 2011,with a growth rate of 6%and 45.3%,respectively,year-on-year. The significant increase in demand for oil and the caused structural contradictions are increasingly becoming the greatest challenge for China’s energy security. The energy crisis has not only touched everyone’s nerves,but also sparked a strong desire to find alternative energy.

  15. Production of bio-energy from low-value biomass by bioconversion

    Institute of Scientific and Technical Information of China (English)

    Tan Tianwei

    2014-01-01

    Since 1993, China has become a net importer of energy from a net exporter. The total energy con- sumption has been greater than the total supply, and the external dependence of the energy demand increases rapidly. China' s crude oil import volume and imports amount reached 253.78 million tons and 196.664 billion US dollars in 2011, with a growth rate of 6 % and 45.3 %, respectively, year-on-year. The significant increase in demand for oil and the caused structural contradictions are increasingly becoming the greatest challenge for China' s energy security. The energy crisis has not only touched everyone' s nerves, but also sparked a strong desire to find alternative energy.

  16. A comprehensive model of anaerobic bioconversion of complex substrates to biogas

    DEFF Research Database (Denmark)

    Angelidaki, Irini; Ellegaard, Lars; Ahring, Birgitte Kiær

    1999-01-01

    .e., carbohydrates, lipids, and proteins, the concentration of intermediates such as volatile fatty acids and long-chain fatty acids, and important inorganic components, i.e., ammonia, phosphate, cations, and anions. This allows dynamic changes of the process during a shift of substrate composition to be simulated......) constitute the primary modulating factors in the model. The model was rested with success in lab-scale reactors codigesting manure with glycerol trioleate or manure with gelatin. Finally, the model was validated using results from a full-scale biogas plant codigesting manure together with a proteinous...

  17. Enantioselective bioconversion using Escherichia coli cells expressing Saccharomyces cerevisiae reductase and Bacillus subtilis glucose dehydrogenase.

    Science.gov (United States)

    Park, Hyun Joo; Jung, Jihye; Choi, Hyejeong; Uhm, Ki-Nam; Kim, Hyung Kwoun

    2010-09-01

    Ethyl (R, S)-4-chloro-3-hydroxybutanoate (ECHB) is a useful chiral building block for the synthesis of L-carnitine and hypercholesterolemia drugs. The yeast reductase, YOL151W (GenBank locus tag), exhibits an enantioselective reduction activity, converting ethyl-4-chlorooxobutanoate (ECOB) exclusively into (R)-ECHB. YOL151W was generated in Escherichia coli cells and purified via Ni- NTA and desalting column chromatography. It evidenced an optimum temperature of 45 degrees C and an optimum pH of 6.5-7.5. Bacillus subtilis glucose dehydrogenase (GDH) was also expressed in Escherichia coli, and was used for the recycling of NADPH, required for the reduction reaction. Thereafter, Escherichia coli cells co-expressing YOL151W and GDH were constructed. After permeablization treatment, the Escherichia coli whole cells were utilized for ECHB synthesis. Through the use of this system, the 30 mM ECOB substrate could be converted to (R)-ECHB.

  18. Bioconversion of apigenin-7-O-β-glucoside in aqueous two-phase system

    Directory of Open Access Journals (Sweden)

    Ilić Sanja M.

    2005-01-01

    Full Text Available The study is concerned with the conversion of apigenin-7-O-β-glucoside into apigenin in polyethylene glycol 6000 / dextran 20000 aqueous two-phase system by β-glucosidase. Apigenin was separated from apigenin-7-O-β-glucoside and β-glucosidase by their partition into opposite phases. In 14% PEG / 22.5% DEX aqueous two-phase system obtained yield of apigenin in top phase was 108%.

  19. Pilot plant studies of the bioconversion of cellulose and production of ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Wilke, C.R.

    1977-06-30

    Progress is reported in the following studies on analysis and evaluation of potential raw materials: preliminary pretreatment studies using wheat straw; extraction of wheat straw with alcohol and water at elevated temperatures; extraction of ground wood with alcohol and water at elevated temperatures; and, delignification of newsprint with ethylene glycol. Other research in progress includes studies on: utilization of hemicellulose sugars; process design and economics of hydrolysis processes and ethanol fermentation; and, pilot plant process development and design, including cell-recycle systems for cellulase production, continuous hydrolysis, countercurrent hydrolysis, and ethanol fermentation studies. (JGB)

  20. BIOCONVERSION OF KNOT REJECTS FROM A SULPHITE PULP MILL TO ETHANOL

    Directory of Open Access Journals (Sweden)

    Xiao Zhang

    2010-02-01

    Full Text Available Knot rejects obtained from pulp screening after sulphite pulping are difficult to dewater, which makes landfilling expensive and burning inefficient. The rejects were found to contain up to 50% cellulose, which is very susceptible to enzymatic hydrolysis to glucose. Knot rejects were hydrolyzed at 20% consistency in a laboratory peg mixer with cellulase enzyme. The thick slurry was liquefied within the first hour of mixing and resulted in a glucose concentration of over 100 g/L after 24 hours of reaction. This solution was fermented by yeast to give an ethanol concentration of over 5%. The laboratory results were confirmed at pilot scale with a mortar mixer (high consistency or stirred tank reactor (medium consistency at the 400 L and 6000 L scales, respectively. It was found that washing the knots with ammonia resulted in increased glucose conversion. Enzyme costs could be lowered by separating the enzyme from the hydrolyzed sugars by membrane ultrafiltration and recycling the enzyme to the subsequent batch of substrate. The combination of high-consistency hydrolysis and enzyme recycling minimizes capital investment, energy requirements, and enzyme costs, which are significant factors in the overall economic viability of cellulose conversion to ethanol.

  1. In vivo nitrate tolerance is not associated with reduced bioconversion of nitroglycerin to nitric oxide

    DEFF Research Database (Denmark)

    Laursen, J B; Mülsch, A; Boesgaard, S;

    1996-01-01

    left untreated (control). Nitrate tolerance was substantiated by a reduced (55% to 85%) hypotensive response to NTG in vivo and a reduced relaxation to NTG in isolated aortic rings. NTG-derived NO formation in aorta, vena cava, heart, and liver was measured as NOFe(DETC)2 and NO-heme complexes formed...

  2. Bioconversion of renewable resources into ethanol: An economic evaluation of selected hydrolysis, fermentation, and membrane technologies

    Energy Technology Data Exchange (ETDEWEB)

    Qureshi, N. [Univ. of Nebraska, Lincoln, NE (United States). Dept. of Biological Systems Engineering; Manderson, G.J. [Massey Univ., Palmerston North (New Zealand). Dept. of Process and Environmental Technology

    1995-03-01

    Four renewable agricultural resources were considered in a process design analysis for the industrial production of ethanol. Raw materials considered were wood, molasses, whey permeate, and starch. Final fermentation substrates were diluted and/or concentrated to give equivalent sugar concentrations for each case. Renewable resource costs were expressed as $/kg of sugar rather than /kg of the raw material. Molasses sugars were cheaper than sugars derived from the other raw materials. Various fermentation technologies were considered, including continuous culture and cell recycle. Ethanol recovery was examined using pervaporation and costs compared with distillation. The effects on ethanol prices of raw material costs, fermentation technology, product recovery, tax, plant size, and Lang factor are presented. Cultures of Candida shehatae, Zymomonas mobilis, Kluyveromyces marxianus var. lactis and Saccharomyces cerevisiae (with Zymomonas mobilis) were used, depending on the substrate. The report identifies the most appropriate technologies in terms of final ethanol price.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1981-01-01

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

  4. An integrated bioconversion process for the production of L-lactic acid from starchy feedstocks

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, S.P.; Moon, S.H.

    1997-07-01

    The potential market for lactic acid as the feedstock for biodegradable polymers, oxygenated chemicals, and specialty chemicals is significant. L-lactic acid is often the desired enantiomer for such applications. However, stereospecific lactobacilli do not metabolize starch efficiently. In this work, Argonne researchers have developed a process to convert starchy feedstocks into L-lactic acid. The processing steps include starch recovery, continuous liquefaction, and simultaneous saccharification and fermentation. Over 100 g/L of lactic acid was produced in less than 48 h. The optical purity of the product was greater than 95%. This process has potential economical advantages over the conventional process.

  5. Bioconversion of wastewater from sweet potato starch production to Paenibacillus polymyxa biofertilizer for tea plants.

    Science.gov (United States)

    Xu, Shengjun; Bai, Zhihui; Jin, Bo; Xiao, Runlin; Zhuang, Guoqiang

    2014-01-01

    Wastewater from the sweet potato starch industry is a large source of nutrient-rich substrates. We assessed whether this wastewater could be used to produce Paenibacillus polymyxa biofertilizer for foliar application to tea trees. Using the central composite design methods we experientially determined that the optimal culture conditions for P. polymyxa were pH, 6.5; temperature, 29.0 °C; and incubation time, 16 h. Under these conditions, a maximum biomass of 9.7 × 10(9) cfu/mL was achieved. We then conducted a yearlong field investigation to determine the effect of P. polymyxa biofertilizer on the growth of tea plants (Camellia sinensis). Tea yield, quantity of water extract, and tea polyphenol levels were significantly higher after foliar application of the biofertilizer compared to that in the controls by an average of 16.7%, 6.3%, and 10.4%, respectively. This approach appears to be technically feasible for organic tea production, and is an environmentally friendly way to utilize wastewater.

  6. Production of natural flavour compounds: bioconversion of monoterpenes by spores of Penicillium digitatum

    NARCIS (Netherlands)

    Wolken, W.A.M.

    2003-01-01

    Consumers prefer natural over artificial additives. Consequently natural flavour-compounds fetch higher prices than the corresponding artificial compound. Various natural means of flavour production are discussed in this dissertation. The major part is focused on the biotransformation of geraniol in

  7. Bioconversions of Palm Kernel Cake and Rice Bran Mixtures by Trichoderma viride Toward Nutritional Contents

    Directory of Open Access Journals (Sweden)

    Yana Sukaryana

    2010-12-01

    Full Text Available The objective of the research is to examine the mixtures of palm kernel cake and rice bran of fermented by Trichoderma viride. Completely randomized design in factorial pattern 4 x 4 was used in this experiment. factor I is the doses of inoculums; D1 = 0%, D2 =  0,1% , D3 =  0,2%, D4 =  0,3%, and  complement factor II is mixtures of palm kernel cake and rice bran : T1=20:80% ; T2=40:60% ; T3=60:40% ; T4=80:20%. The treatment each of three replicate. Fermentation was conducted at temperature 28 oC as long as 9 days. Determining the best of the mixtures be based on the crude protein increased and the crude fibre decreased. The results showed that the combination of product mix is the best fermentation inoculums doses 0.3% in mixture of palm kernel cake and rice bran ; 80%: 20%, which produces dry matter of 88,12%, crude protein 17.34%, ether extract 5,35%, crude fibre 23.67%, and ash 6.43%. When compared with a mixture of palm kernel cake and rice bran; 80%: 20% without of fermentation is crude protein increase 29.58% and crude fibre decreased 22.53%.

  8. Bioconversion of starch processing waste to Phellinus linteus mycelium in solid-state cultivation.

    Science.gov (United States)

    Lee, Seungyong; Bae, Hyokwan; Song, Minkyung; Hwang, Seokhwan

    2008-08-01

    The objective of the experiment was to use starch processing waste as an alternative growth medium for cultivation of mycelia of the mushroom Phellinus linteus and to find an optimum condition under solid-state cultivation. Response surface analysis along with a central composite design was successfully applied to approximate the simultaneous effects of the substrate concentration (16-36 g l(-1)), pH (4.5-6.5), and temperature (25-35 degrees C) on the mycelial growth rate. In the model, pH and temperature significantly affected the mycelial growth but substrate concentration did not. The optimal substrate concentration, pH, and temperature for maximizing growth rate of P. linteus mycelia were found to be 16.5 g l(-1), pH 6.0, and 29.7 degrees C, respectively. Subsequent verification of these levels agreed with model predictions and the maximum mycelial growth rate at these conditions was 6.1 +/- 0.8 mm day(-1). Therefore, the results of the experiments suggest that starch processing waste could be utilized as a growth substrate for the cultivation of the mushroom mycelia of P. linteus, enhancing the usefulness of this byproduct of the starch manufacturing industry. This approach is likely to be useful for establishing similar parameters for the cultivation of other fungi.

  9. Solvent-tolerant bioconversion: construction and analysis of a phenol producing Pseudomonas putida S12

    NARCIS (Netherlands)

    Wierckx, N.J.P

    2009-01-01

    Organic chemicals play a fundamental role in modern civilization. Today, almost all of these chemicals are produced from oil. This leads to pollution and creates a dependency on often politically unstable oil producing countries. It is possible to make the same chemicals from sugar, using microorgan

  10. Bioconversion of apple pomace into a nutritionally enriched substrate by Candida utilis and Pleurotus ostreatus

    DEFF Research Database (Denmark)

    Villas-Bôas, Silas Granato; Esposito, E.; de Mendonca, M.M.

    2003-01-01

    Apple production in the world has increased significantly over the last 10 years. A considerable fraction of these fruits, mainly those not approved for fresh consumption, is industrially processed to produce juices, flavours and concentrates. During this processing, a large amount of solid...

  11. Preparation and characterization of whey protein hydrolysates: applications in industrial whey bioconversion processes.

    Science.gov (United States)

    Perea, A; Ugalde, U; Rodriguez, I; Serra, J L

    1993-05-01

    A whey protein hydrolysate was prepared by incubation of reconstituted whey or a whey protein concentrate with Alcalase 0.6L. The proteolytic degradation of alpha-lactalbumin and beta-lactoglobulin initially resulted in 6-kDa and, later, 2.5-kDa degradation products, quickly followed by the appearance of multiple peptides of 1 kDa or smaller. The hydrolysate showed a steady increase in solubility and a biphasic change in foaming characteristics with decreasing peptide size. At the highest degree of hydrolysis achieved (22%), the majority of the peptides were smaller than 1 kDa and could be efficiently assimilated by the yeast Kluyveromyces marxianus growing in a defined medium.

  12. Reduction of Non-CO2 Gas Emissions Through The In Situ Bioconversion of Methane

    Energy Technology Data Exchange (ETDEWEB)

    Scott, A R; Mukhopadhyay, B; Balin, D F

    2012-09-06

    The primary objectives of this research were to seek previously unidentified anaerobic methanotrophs and other microorganisms to be collected from methane seeps associated with coal outcrops. Subsurface application of these microbes into anaerobic environments has the potential to reduce methane seepage along coal outcrop belts and in coal mines, thereby preventing hazardous explosions. Depending upon the types and characteristics of the methanotrophs identified, it may be possible to apply the microbes to other sources of methane emissions, which include landfills, rice cultivation, and industrial sources where methane can accumulate under buildings. Finally, the microbes collected and identified during this research also had the potential for useful applications in the chemical industry, as well as in a variety of microbial processes. Sample collection focused on the South Fork of Texas Creek located approximately 15 miles east of Durango, Colorado. The creek is located near the subsurface contact between the coal-bearing Fruitland Formation and the underlying Pictured Cliffs Sandstone. The methane seeps occur within the creek and in areas adjacent to the creek where faulting may allow fluids and gases to migrate to the surface. These seeps appear to have been there prior to coalbed methane development as extensive microbial soils have developed. Our investigations screened more than 500 enrichments but were unable to convince us that anaerobic methane oxidation (AMO) was occurring and that anaerobic methanotrophs may not have been present in the samples collected. In all cases, visual and microscopic observations noted that the early stage enrichments contained viable microbial cells. However, as the levels of the readily substrates that were present in the environmental samples were progressively lowered through serial transfers, the numbers of cells in the enrichments sharply dropped and were eliminated. While the results were disappointing we acknowledge that anaerobic methane oxidizing (AOM) microorganisms are predominantly found in marine habitats and grow poorly under most laboratory conditions. One path for future research would be to use a small rotary rig to collect samples from deeper soil horizons, possibly adjacent to the coal-bearing horizons that may be more anaerobic.

  13. Bioconversion of municipal solid waste to glucose for bio-ethanol production.

    Science.gov (United States)

    Li, Aiduan; Antizar-Ladislao, Blanca; Khraisheh, Majeda

    2007-05-01

    Selected biodegradable municipal solid waste fractions were subjected to fifteen different pre-hydrolysis treatments to obtain the highest glucose yield for bio-ethanol production. Pre-hydrolysis treatments consisted of dilute acid (H(2)SO(4), HNO(3) or HCl, 1 and 4%, 180 min, 60 degrees C), steam treatment (121 and 134 degrees C, 15 min), microwave treatment (700 W, 2 min) or a combination of two of them. Enzymatic hydrolysis was carried out with Trichoderma reesei and Trichoderma viride (10 and 60 FPU g(-1) substrate). Glucose yields were compared using a factorial experimental design. The highest glucose yield (72.80%) was obtained with a pre-hydrolysis treatment consisting of H(2)SO(4) at 1% concentration, followed by steam treatment at 121 degrees C, and enzymatic hydrolysis with Trichoderma viride at 60 FPU g(-1) substrate. The contribution of enzyme loading and acid concentration was significantly higher (49.39 and 47.70%, respectively), than the contribution of temperature during steam treatment (0.13%) to the glucose yield.

  14. Bioconversion of kitchen garbage to lactic acid by two wild strains of Lactobacillus species.

    Science.gov (United States)

    Wang, Qunhui; Wang, Xuming; Wang, Xiaoqiang; Ma, Hongzhi; Ren, Nanqi

    2005-01-01

    To enhance lactic acid (LA) production from kitchen garbage, which is a raw material for biodegradable plastics production, the application of high-performance lactic acid bacteria (LAB) as inocula was investigated. Two wild strains of Lactobacillus species, designated as TH165 and TD175, were isolated and screened from kitchen garbage. Strain TH165 was capable of hydrolyzing starch to produce LA; 49.5% of starch was broken down in fermentation medium containing 8.52 g/L of soluble starch, and 4.01 g/L of LA was produced after 24 h fermentation at 37 degrees C without pH control. Strain TD175 could produce 16.06 g/L of LA, 66.9% higher than that of Lactobacillus bulgaricus ACCC11058 in fermentation medium containing 2.0% glucose at 30 degrees C without pH control. Furthermore, coinoculation of strains TH165 and TD175 enhanced the LA production, resulting in 33.80 g/L of LA concentration and 0.46 g/g (DW) of LA yield from nonautoclaved kitchen garbage after 72 h fermentation with pH maintained at 5.5-6.0, values 36.9% higher than those of the fermentation without inoculum (control). This study shows that enhancement of LA production from kitchen garbage can be realized by using high-performance LAB. This recycling system is conducive to clear away pollutants and to reduce cost of LA production.

  15. Preparation of 6-APA by Enzymatic Bioconversion in an Emulsion Liquid Membrane Reactor

    Institute of Scientific and Technical Information of China (English)

    陆强; 胡鸣; 熊丹柳; 邓修

    2001-01-01

    Production of 6-aminopenicillanic acid (6-APA) by hydrolysis using penicillin acylase (PA) was studied as a model of an enzymatic emulsion liquid membrane (ELM) process. The loss of PA activity was examined for various membrane compositions (organic solvent, surfactant, carrier). The effects of some experimental variables on the stability of emulsion were investigated. It was found that the choice of organic solvent greatly affected tilestability of the emulsion. Increasing the concentration of the carrier in the membrane phase increases the transfer rate of substrate and products but also has a destabilizing effect on the emulsion. The recovery of 6-APA obtained by a di-carrier system (N263-N1923) was much higher than those when either of the di-carriers was used separately.The whole process was controlled both by the enzymatic reaction rate and by the transfer rate of the substrate and the products, however, the ratio of them could be changed by varying the composition of the system. For an optimum condition, it was obtained that the recovery ratio of 6-APA was over 80% and the conversion of benzyl penicillin (PG) was up to 90% in the external phase after 30 minutes. Meanwhile, the breakage percentage of the emulsion was less than 2%.

  16. Enhanced bioconversion of ethylene glycol to glycolic acid by a newly isolated Burkholderia sp. EG13.

    Science.gov (United States)

    Gao, Xiaoxin; Ma, Zhengfei; Yang, Limin; Ma, Jiangquan

    2014-10-01

    Burkholderia sp. EG13 with high ethylene glycol-oxidizing activity was isolated from soil, which could be used for the synthesis of glycolic acid from the oxidation of ethylene glycol. Using the resting cells of Burkholderia sp. EG13 as biocatalysts, the optimum reaction temperature and pH were 30 °C and 6.0, respectively. After 24 h of biotransformation, the yield of glycolic acid from 200 mM ethylene glycol was 98.8 %. Furthermore, an integrated bioprocess for the production of glycolic acid which involved in situ product removal (ISPR) was investigated. Using fed-batch method with ISPR, a total of 793 mM glycolic acid has been accumulated in the reaction mixture after the 4th feed.

  17. Stocking Density Optimization for Enhanced Bioconversion of Fly Ash Enriched Vermicompost.

    Science.gov (United States)

    Mupambwa, Hupenyu A; Mnkeni, Pearson N S

    2016-05-01

    Although it is widely agreed that stocking density critically affects the rate of vermicomposting, there is no established stocking density for mixtures of fly ash and other waste materials. This study sought to optimize (Savigny, 1826) stocking density for effective biodegradation and nutrient release in a fly ash-cow dung-waste paper (FCP) mixture. Four stocking densities of 0, 12.5, 25, and 37.5 g worms kg were evaluated. Although the 12.5, 25, and 37.5 g worms kg treatments all resulted in a mature vermicompost, stocking densities of 25 and 37.5 g worms kg resulted in faster maturity, higher humification parameters, and a significantly lower final C/N ratio (range 11.1-10.4). The activity of β-glucosidase and fluorescein diacetate hydrolysis enzymes showed faster stabilization at stocking densities of 25 and 37.5 g worms kg, indicating compost stability and maturity. Similarly, a stocking density of 25 g worms kg resulted in the highest release of Olsen-extractable P and (NO + NO)-N contents. The 0-, 12.5-, 25-, and 37.5-g treatments resulted in net Olsen P increases of 16.3, 38.9, 61.0, and 53.0%, respectively, after 10 wk. Although compost maturity could be attained at stocking densities of 12.5 g worms kg, for faster production of humified and nutrient-rich FCP vermicompost, a stocking density of 25 g worms kg seems most appropriate.

  18. COMBINED COMPOST AND VERMICOMPOSTING PROCESS IN THE TREATMENT AND BIOCONVERSION OF SLUDGE

    Directory of Open Access Journals (Sweden)

    H. Alidadi, A. R. Parvaresh and M. R. Shamansouri

    2005-10-01

    Full Text Available Traditional thermophillic composting is commonly for treatment of sludge. A related technique as vermicomposting process, using earthworms to breakdown sludge, is also becoming popular. These two techniques have their inherent advantages and disadvantages. The combined approach suggested in this study to enhance the overall process and improve the products qualities. Two systems,vermicomposting and combined compost vermicomposting processes, have been investigated in this study. The sludge used in this study was obtained from the drying beds of South Isfahan wastewater treatment plant.The sludge mixed with sawdust to provide C/N ratio of 25/1.Eisenia fetida was the species of earthworms used in the vermicomposting processes.The results obtained indicates reduction in the amount of volatile solids,total carbon and C/N ratio with the vermicompost age,which indicates the reduction in the biodegradable organic content and mineralization of sludge. Also increase in phosphorus concentration by the end process because of mineralization of organic matter. The results indicate that, a system that combines the two mentioned processes not only shortens stabilization time, but also improves the products quality. Combining the two systems resulted in a product that was more stable and homogenous; the product could meet the pathogen reduction requirements.

  19. Asymmetric Bioconversion of Acetophenone in Nano-Sized Emulsion Using Rhizopus oryzae.

    Science.gov (United States)

    Li, Qingzhi; Shi, Yang; He, Le; Zhao, Hui

    2016-01-01

    The fungal morphologies and pellet sizes were controlled in acetophenone reduction by Rhizopus oryzae. The acetophenone conversion and (S)-phenylethanol enantiomeric excesses (e.e.) reached the peak after 72 h of incubation when using pellets with 0.54 mm diameter, which showed an excellent performance compared with suspended mycelia, clumps, and pellets with 0.65 or 0.75 mm diameter. Furthermore, nano-sized acetophenone was used as a substrate to improve the performances of biotransformation work. The results showed that the conversion of nanometric acetophenone and (S)-phenylethanol e.e. reached the maximum (both >99%) after 32 h of incubation when using 0.54 mm diameter pellets, at least 24 h in advance of the control group. On the other hand, Tween 80 and 1, 2-propylene glycol showed low or no toxicity to cells. In conclusion, pellets and acetophenone nanoemulsions synergistically result in superior performances of acetophenone reduction.

  20. Advanced anaerobic bioconversion of lignocellulosic waste for the melissa life support system

    Science.gov (United States)

    Lissens, G.; Verstraete, W.; Albrecht, T.; Brunner, G.; Creuly, C.; Dussap, G.; Kube, J.; Maerkl, H.; Lasseur, C.

    The feasibility of nearly-complete conversion of lignocellulosic waste (70% food crops, 20% faecal matter and 10% green algae) into biogas was investigated in the context of the MELiSSA loop (Micro-Ecological Life Support System Alternative). The treatment comprised a series of processes, i.e. a mesophilic laboratory scale CSTR (continuously stirred tank reactor), an upflow biofilm reactor, a fiber liquefaction reactor employing the rumen bacterium Fibrobacter succinogenes and a hydrothermolysis system in near-critical water. By the one-stage CSTR, a biogas yield of 75% with a specific biogas production of 0.37 l biogas g-1 VSS (volatile suspended solids) added at a RT (hydraulic retention time) of 20-25 d was obtained. Biogas yields could not be increased considerably at higher RT, indicating the depletion of readily available substrate after 25 d. The solids present in the CSTR-effluent were subsequently treated in two ways. Hydrothermal treatment (T ˜ 310-350C, p ˜ 240 bar) resulted in effective carbon liquefaction (50-60% without and 83% with carbon dioxide saturation) and complete sanitation of the residue. Application of the cellulolytic Fibrobacter succinogenes converted remaining cellulose contained in the CSTR-effluent into acetate and propionate mainly. Subsequent anaerobic digestion of the hydrothermolysis and the Fibrobacter hydrolysates allowed conversion of 48-60% and 30%, respectively. Thus, the total process yielded biogas corresponding with conversions up to 90% of the original organic matter. It appears that particularly mesophilic digestion in conjunction with hydrothermolysis offers interesting features for (nearly) the MELiSSA system. The described additional technologies show that complete and hygienic carbon and energy recovery from human waste within MELiSSA is technically feasible, provided that the extra energy needed for the thermal treatment is guaranteed.

  1. Bioconversion of ginsenoside Rb1 into compound K by Leuconostoc citreum LH1 isolated from kimchi

    Directory of Open Access Journals (Sweden)

    Lin-Hu Quan

    2011-09-01

    Full Text Available About 40 different types of ginsenoside (ginseng saponin, a major pharmacological component of ginseng, have been identified along with their physiological activities. Among these, compound K has been reported to prevent the development of and the metastasis of cancer by blocking the formation of tumors and suppressing the invasion of cancerous cells. In this study, ginsenoside Rb1 was converted into compound K via interaction with the enzyme secreted by β-glucosidase active bacteria, Leuconostoc citreum LH1, extracted from kimchi. The optimum time for the conversion of Rb1 to compound K was about 72 hrs at a constant pH of 6.0 and an optimum temperature of about 30ºC. Under optimal conditions, ginsenoside Rb1 was decomposed and converted into compound K by 72 hrs post-reaction (99%. Both TLC and HPLC were used to analyze the enzymatic reaction. Ginsenoside Rb1 was consecutively converted to ginsenoside Rd, F2, and compound K via the hydrolyses of 20-C β-(1 → 6-glucoside, 3-C β-(1 → 2glucoside, and 3-C β-glucose of ginsenoside Rb1.

  2. Bioconversion of Biomass-Derived Phenols Catalyzed by Myceliophthora thermophila Laccase

    Directory of Open Access Journals (Sweden)

    Anastasia Zerva

    2016-04-01

    Full Text Available Biomass-derived phenols have recently arisen as an attractive alternative for building blocks to be used in synthetic applications, due to their widespread availability as an abundant renewable resource. In the present paper, commercial laccase from the thermophilic fungus Myceliophthora thermophila was used to bioconvert phenol monomers, namely catechol, pyrogallol and gallic acid in water. The resulting products from catechol and gallic acid were polymers that were partially characterized in respect to their optical and thermal properties, and their average molecular weight was estimated via solution viscosity measurements and GPC. FT-IR and 1H-NMR data suggest that phenol monomers are connected with ether or C–C bonds depending on the starting monomer, while the achieved molecular weight of polycatechol is found higher than the corresponding poly(gallic acid. On the other hand, under the same condition, pyrogallol was dimerized in a pure red crystalline compound and its structure was confirmed by 1H-NMR as purpurogallin. The herein studied green synthesis of enzymatically synthesized phenol polymers or biological active compounds could be exploited as an alternative synthetic route targeting a variety of applications.

  3. Multidisciplinary research program directed toward utilization of solar energy through bioconversion of renewable resources

    Energy Technology Data Exchange (ETDEWEB)

    1980-07-01

    Progress is reported in this multidisciplinary research program. Genetic selection of superior trees, physiological basis of vigor, tissue culture systems leading to cloning of diploid and haploid cell lines are discussed in the Program A report. The physiological basis of enhanced oleoresin formation in southern pines when treated with sublethal concentrations of the herbicide paraquat was investigated in Program B. In Program C, metabolic changes in the stems of slash pine, in vivo, after application with paraquat were determined. The use of phdoem and xylem tissue slices as a laboratory model for studying paraquat associated- and normal-terpene synthesis in pines is discussed. The biochemistry and physiology of methane formation from cellulose during anaerobic fermentation are discussed in the Program D report. (DMC)

  4. [BIOCONVERSION OF CRUDE GLYCEROL AND MOLASSES MIXTURE IN BIOSURFACTANTS OF NOCARDIA VACCINII IMB B-7405].

    Science.gov (United States)

    Pirog, T P; Kudrya, N V; Shevchuk, T A; Beregova, K A; Iutynska, G O

    2015-01-01

    The possibility of replacing glucose and pure glycerol in mixed substrates for surtace-active substances (SAS, biosurfactants) biosynthesis of Nocardia vaccinii IMB B-7405 on molasses (sugar production waste) and crude glycerol (by-product of biodiesel production) was established. It was established that the increasing concentration of crude glycerol to 6% in mixture with 1.0% molasses was accompanied by increase of amount of SAS synthesized more than twice, and the increasing content of molasses to 3.0% in mixture with 1.0% crude glycerol--by some decrease in the level of surfactant as compared to that in a medium containing 1.0% monosubstrates. It was shown that the increasing concentration of sodium nitrate to 2-fold in medium cultivation of N. vaccinii IMB B-7405 allowed to increase to 7.0% content of grude glycerol in mixture with 1.0% molasses. Under such conditions of cultivation concentration of exocellular SAS synthesized was 7,5 g/l, that to 1,3 fold higher than in basic medium with a lower content of nitrogen source.

  5. Bioconversion of volatile fatty acids into lipids by the oleaginous yeast Yarrowia lipolytica.

    Science.gov (United States)

    Fontanille, Pierre; Kumar, Vinod; Christophe, Gwendoline; Nouaille, Régis; Larroche, Christian

    2012-06-01

    The valorization of volatile fatty acids into microbial lipids by the oleaginous yeast Yarrowia lipolytica was investigated. Therefore, a two-stage fed-batch strategy was designed: the yeast was initially grown on glucose or glycerol as carbon source, then sequential additions of acetic acid under nitrogen limiting conditions were performed after glucose or glycerol exhaustion. The typical values obtained with an initial 40 g/L concentration of glucose were close to 31 g/L biomass, a lipid concentration of 12.4 g/L, which correspond to a lipid content of the biomass close to 40%. This cultivation strategy was also efficient with other volatile fatty acids (butyric and propionic acids) or with a mixture of these three VFAs. The lipids composition was found quite similar to that of vegetable oils. The study demonstrated the feasibility of simultaneous biovalorization of volatile fatty acids and glycerol, two cheap industrial by-products.

  6. Bioconversion of Waste Gases into Biofuel via Fermentation in a Continuous Stirred Tank Bioreactor

    Directory of Open Access Journals (Sweden)

    Najafpour, G.

    2005-01-01

    Full Text Available Biological hydrogen production was carried out in a continuous stirred tank bioreactor. A photosynthetic bacterium, Rhodospirillum rubrum, was used as biocatalyst to oxidize carbon monoxides in the waste gas generated from biomass in a gasification process. The fresh liquid media was supplied for microbial growth which contained sodium acetate as carbon source at initial concentration of 4 gL-1. The optimum media space velocity or the suitable ratio of liquid flow rate to the reactor volume (F/VL was 0.02 h-1. At the steady state condition, the concentration of acetate was independent of the dilution rate and it was approximately 1.5 gL-1. The average cell dry weight in the fermentation broth was at satisfactory concentration, approximately 3.4 gL-1 with dilution rate at 0.55 mL min-1. The maximum value of KLa and CO conversion were about 58 h-1 and 80%, respectively, with agitation speed at 500 rpm and gas flow rate at 14 mL min-1. At this condition, the maximum yield of hydrogen production was 0.82 mmol H2•mmol-1 CO.

  7. Bioconversion of acrylonitrile to acrylamide using polyacrylamide entrapped cells of Rhodococcus rhodochrous PA-34.

    Science.gov (United States)

    Raj, J; Prasad, S; Sharma, N N; Bhalla, T C

    2010-09-01

    The nitrile hydratase (NHase) of Rhodococcus rhodochrous PA-34 catalyzed the conversion of acrylonitrile to acrylamide. The resting cells (having NHase activity) (8 %; 1 mL corresponds to 22 mg dry cell mass, DCM) were immobilized in polyacrylamide gel containing 12.5 % acrylamide, 0.6 % bisacrylamide, 0.2 % diammonium persulfate and 0.4 % TEMED. The polyacrylamide entrapped cells (1.12 mg DCM/mL) completely converted acrylonitrile in 3 h at 10 °C, using 0.1 mol/L potassium phosphate buffer. In a partitioned fed batch reactor, 432 g/L acrylamide was accumulated after 1 d. The polyacrylamide discs were recycled up to 3×; 405, 210 and 170 g/L acrylamide was produced in 1st, 2nd and 3rd recycling reactions. In four cycles, a total of 1217 g acrylamide was produced by recycling the same mass of entrapped cells.

  8. Bioconversion of waste office paper to hydrogen using pretreated rumen fluid inoculum.

    Science.gov (United States)

    Botta, Lívia Silva; Ratti, Regiane Priscila; Sakamoto, Isabel Kimiko; Ramos, Lucas Rodrigues; Silva, Edson Luiz; Varesche, Maria Bernadete Amâncio

    2016-12-01

    In this study, a microbial consortium from an acid-treated rumen fluid was used to improve the yields of H2 production from paper residues in batch reactors. The anaerobic batch reactors, which contained paper and cellulose, were operated under three conditions: (1) 0.5 g paper/L, (2) 2 g paper/L, and (3) 4 g paper/L. Cellulase was added to promote the hydrolysis of paper to soluble sugars. The H2 yields were 5.51, 4.65, and 3.96 mmol H2/g COD, respectively, with substrate degradation ranging from 56 to 65.4 %. Butyric acid was the primary soluble metabolite in the three reactors, but pronounced solventogenesis was detected in the reactors incubated with increased paper concentrations (2.0 and 4.0 g/L). A substantial prevalence of Clostridium acetobutylicum (99 % similarity) was observed in the acid-treated rumen fluid, which has been recognized as an efficient H2-producing strain in addition to ethanol and n-butanol which were also detected in the reactors.

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

    Science.gov (United States)

    Markou, Giorgos; Angelidaki, Irini; Georgakakis, Dimitris

    2012-11-01

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

  10. Screening and bioconversion of glycyrrhizin of Glycyrrhiza glabra root extract to 18β-glycyrrhetinic acid by different microbial strains

    Directory of Open Access Journals (Sweden)

    Makhmur Ahmad

    2016-01-01

    Full Text Available Objective: The objective of the present study is to perform screening of different microorganisms (7 bacteria and 14 fungi for conversion of glycyrrhizin (GL to 18β-glycyrrhetinic acid (GA. Penicillium chrysogenum produced the highest concentration of β-glucuronidase enzyme (61 U/mL and produced GA of 52 μg/mL while E. coli produced the highest β-glucuronidase of 376 U/mL with GA concentration of 2.1 μg/mL. Materials and Methods: Submerged and solid state biotransformation of GL was carried out. To 9.0 mL of bacterial supernatant, 1.0 mL 0.2% w/v of aqueous Glycyrrhiza glabra root extract was added and incubated at 37°C for 24 h. β-glucuronidase activity was measured and high-performance liquid chromatography analysis was carried out. Results and Discussion: Induced-Escherichia coli produces 2.1 μg/mL of GA with an enzyme activity of 376 U/mL which shows that the enzyme has a potential biotransformation capability. Rhizopus oryzae and P. chrysogenum have the potential ability to biotransform GL to GA with 2.6 μg/mL and 61 μg/mL of GA with enzyme activity of 569 U/mL and 61 U/mL, respectively. Conclusions: G. glabra roots containing GL can be hydrolyzed by microbial β-glucuronidase enzyme under sub-merged fermentation (SmF. β-glucuronidase, an enzyme of E. coli, was found to be the best microbial source of enzyme which biocatalyzed the reaction than fungal strain under SmF.

  11. Bioconversion of methanol to value-added mevalonate by engineered Methylobacterium extorquens AM1 containing an optimized mevalonate pathway.

    Science.gov (United States)

    Zhu, Wen-Liang; Cui, Jin-Yu; Cui, Lan-Yu; Liang, Wei-Fan; Yang, Song; Zhang, Chong; Xing, Xin-Hui

    2016-03-01

    Methylotrophic biosynthesis using methanol as a feedstock is a promising and attractive method to solve the over-dependence of the bioindustry on sugar feedstocks derived from grains that are used for food. In this study, we introduced and engineered the mevalonate pathway into Methylobacterium extorquens AM1 to achieve high mevalonate production from methanol, which could be a platform for terpenoid synthesis. We first constructed a natural operon (MVE) harboring the mvaS and mvaE genes from Enterococcus faecalis as well as an artificial operon (MVH) harboring the hmgcs1 gene from Blattella germanica and the tchmgr gene from Trypanosoma cruzi that encoded enzymes with the highest reported activities. We achieved mevalonate titers of 56 and 66 mg/L, respectively, in flask cultivation. Introduction of the phaA gene from Ralstonia eutropha into the operon MVH increased the mevalonate titer to 180 mg/L, 3.2-fold higher than that of the natural operon MVE. Further modification of the expression level of the phaA gene by regulating the strength of the ribosomal binding site resulted in an additional 20 % increase in mevalonate production to 215 mg/L. A fed-batch fermentation of the best-engineered strain yielded a mevalonate titer of 2.22 g/L, which was equivalent to an overall yield and productivity of 28.4 mg mevalonate/g methanol and 7.16 mg/L/h, respectively. The production of mevalonate from methanol, which is the initial, but critical step linking methanol with valuable terpenoids via methylotrophic biosynthesis, represents a proof of concept for pathway engineering in M. extorquens AM1.

  12. Integrated bioconversion of pulp and paper primary sludge to second generation bioethanol using Saccharomyces cerevisiae ATCC 26602.

    Science.gov (United States)

    Mendes, Cátia V T; Cruz, Crispin H G; Reis, Diana F N; Carvalho, M Graça V S; Rocha, Jorge M S

    2016-11-01

    Primary sludge, from different pulp and paper mills, was used as feedstock in simultaneous saccharification and fermentation (SSF) processes to produce ethanol. SSF was carried out with Saccharomyces cerevisiae ATCC 26602 yeast and NS 22192 enzymatic extract using 150gL(-1) of carbohydrates (CH) from primary sludge. The effect of sterilization, reduction of enzyme dosage and fed-batch vs. batch conditions were studied. The removal of sterilization can be considered since no contamination or atypical by-products were observed, although SSF efficiency slightly decreased. The reduction of the enzyme dosage from 35 to 15FPUgCH(-1) was successful. Despite of initial mixing difficulties, batch SSF enabled higher ethanol concentration (41.7gL(-1)), conversion yield (48.9%) and productivity (0.78gL(-1)h(-1)), compared to the fed-batch process at the same conditions of low enzyme dosage of 5FPUgCH(-1) and high solids content of 21.7%, rarely found in literature.

  13. Vanillin-bioconversion and bioengineering of the most popular plant flavor and its de novo biosynthesis in the vanilla orchid.

    Science.gov (United States)

    Gallage, Nethaji J; Møller, Birger Lindberg

    2015-01-01

    In recent years, biotechnology-derived production of flavors and fragrances has expanded rapidly. The world's most popular flavor, vanillin, is no exception. This review outlines the current state of biotechnology-based vanillin synthesis with the use of ferulic acid, eugenol, and glucose as substrates and bacteria, fungi, and yeasts as microbial production hosts. The de novo biosynthetic pathway of vanillin in the vanilla orchid and the possible applied uses of this new knowledge in the biotechnology-derived and pod-based vanillin industries are also highlighted.

  14. Scaled-up bioconversion of fish waste to liquid fertilizer using a 5 L ribbon-type reactor.

    Science.gov (United States)

    Dao, Van Thingoc; Kim, Joong Kyun

    2011-10-01

    A scaled-up conversion process of fish waste to liquid fertilizer was performed in a 5 L ribbon-type reactor. Biodegradation was performed by inoculation of autoclaved fish waste with 5.84 × 10(5) CFU mL(-1) of mixed microorganisms for 96 h. As a result, the pH changed from 6.92 to 5.72, the cell number reached 7.28 × 10(5) CFU mL(-1), and approximately 430 g (28.3%) of fish waste was degraded. Analyses indicated that the 96 h culture of inoculated fish waste possessed comparable fertilizing ability to commercial fertilizers in hydroponic culture with amino acid contents of 6.91 g 100 g(-1). Therefore, the scaled-up production achieved a more satisfactory fish waste degradation rate (3.61 g h(-1)) than the flask-scale production (0.24 g h(-1)). The biodegraded broth of fish waste at room temperature did not undergo putrefaction for 6 months due to the addition of 1% lactate.

  15. Assessing the environmental sustainability of early stage design for bioprocesses under uncertainties: An analysis of glycerol bioconversion

    DEFF Research Database (Denmark)

    Loureiro da Costa Lira Gargalo, Carina; Cheali, Peam; Posada, John A.;

    2016-01-01

    sustainable solutions is a challenging task. This work aims at facilitating the environmental sustainability assessment under uncertainty at the conceptual design of bioprocesses. This, in turn, enables screening design alternatives, and establishing a ranking of the most promising pathways. To this end...... approach suggested ensures consistent and robust ranking of alternatives; thereby identifying lactic acid as the best potential environmentally sustainable alternative within the design space.......The development of a bio-based economy is seen as a key strategy towards a sustainable society in a world facing climate change, energy security and social distress. However, since substantial uncertainty is involved in early-stage design analyses, the ranking and identification of potential...

  16. Simultaneous saccharification of inulin and starch using commercial glucoamylase and the subsequent bioconversion to high titer sorbitol and gluconic acid.

    Science.gov (United States)

    An, Kehong; Hu, Fengxian; Bao, Jie

    2013-12-01

    A new bioprocess for production of sorbitol and gluconic acid from two low-cost feedstocks, inulin and cassava starch, using a commercially available enzyme was proposed in this study. The commercial glucoamylase GA-L NEW from Genencor was found to demonstrate a high inulinase activity for hydrolysis of inulin into fructose and glucose. The glucoamylase was used to replace the expensive and not commercially available inulinase enzyme for simultaneous saccharification of inulin and starch into high titer glucose and fructose hydrolysate. The glucose and fructose in the hydrolysate were converted into sorbitol and gluconic acid using immobilized whole cells of the recombinant Zymomonas mobilis strain. The high gluconic acid concentration of 193 g/L and sorbitol concentration of 180 g/L with the overall yield of 97.3 % were obtained in the batch operations. The present study provided a practical production method of sorbitol and gluconic acid from low cost feedstocks and enzymes.

  17. Bioconversion of barley straw and corn stover to butanol (a biofuel) in integrated fermentation and simultaneous product recovery bioreactors

    Science.gov (United States)

    In these studies concentrated sugar solutions of barley straw and corn stover hydrolysates were fermented with simultaneous product recovery and compared with the performance of a control glucose batch fermentation process. The control glucose batch fermentation resulted in the production of 23.25 g...

  18. Simultaneous biocatalyst production and Baeyer-Villiger oxidation for bioconversion of cyclohexanone by recombinant Escherichia coli expressing cyclohexanone monooxygenase.

    Science.gov (United States)

    Lee, Won-Heong; Park, Yong-Cheol; Lee, Dae-Hee; Park, Kyungmoon; Seo, Jin-Ho

    2005-01-01

    Cyclohexanone monooxygenase (CHMO) catalyzing Baeyer-Villiger oxidation converts cyclic ketones into optically pure lactones, which have been used as building blocks in organic synthesis. A recombinant Escherichia coli BL21(DE3)/pMM4 expressing CHMO originated from Acinetobacter sp. NCIB 9871 was used to produce epsilon-caprolactone through a simultaneous biocatalyst production and Baeyer-Villiger oxidation (SPO) process. A fed-batch process was designed to obtain high cell density for improving production of epsilon-caprolactone. The fed-batch SPO process gave the best results, 10.2 g/L of epsilon-caprolactone and 0.34 g/(L.h) of productivity, corresponding to a 10.5- and 3.4-fold enhancement compared with those of the batch SPO, respectively.

  19. Dynamic bioconversion mathematical modelling and simulation of urban organic waste co-digestion in continuously stirred tank reactor

    DEFF Research Database (Denmark)

    Fitamo, Temesgen Mathewos; Boldrin, Alessio; Dorini, G.

    The application of anaerobic digestion (AD) as process technology is increasing worldwide: the production of biogas, a versatile form of renewable energy, from biomass and organic waste materials allows mitigating greenhouse gas emission from the energy and transportation sectors while treating w...

  20. Increased availability of NADH in metabolically engineered baker's yeast improves transaminase-oxidoreductase coupled asymmetric whole-cell bioconversion

    DEFF Research Database (Denmark)

    Knudsen, Jenny Dahl; Hägglöf, Cecilia; Weber, Nora

    2016-01-01

    yeast for transamination-reduction coupled asymmetric one-pot conversion was investigated. RESULTS: A series of active whole-cell biocatalysts were constructed by over-expressing the (S)-selective ω-transaminase (VAMT) from Capsicum chinense together with the NADH-dependent (S)-selective alcohol...... dehydrogenase (SADH) originating from Rhodococcus erythropolis in strains with or without deletion of glycerol-3-phosphate dehydrogenases 1 and 2 (GPD1 and GPD2). The yeast strains were evaluated as catalysts for simultaneous: (a) kinetic resolution of the racemic mixture to (R)-1-phenylethylamine, and (b......) reduction of the produced acetophenone to (S)-1-phenylethanol. For the gpd1Δgpd2Δ strain, cell metabolism was effectively used for the supply of both amine acceptors and the co-factor pyridoxal-5'-phosphate (PLP) for the ω-transaminase, as well as for regenerating NADH for the reduction. In contrast...

  1. Bioconversion of biomass residue from the cultivation of pea sprouts on spent Pleurotus sajor-caju compost employing Lumbricus rubellus

    Directory of Open Access Journals (Sweden)

    Azizi Abu Bakar

    2012-11-01

    Full Text Available Vermicomposting is a green technology for the purpose of nutrient enrichment from a variety of organic waste products. In this study, saw dust-based spent mushroom compost (SMC, an organic waste and biomass residue, was used as a medium for the cultivation of pea sprouts. After harvesting the pea sprouts, the growth medium was reused to culture earthworms, Lumbricus rubellus. The culturing activity was conducted for 50 days without any pre-composting or thermocomposting. Thus duration of vermicomposting process was shortened as opposed to previous work on vermicomposting of saw dust-based SMC (no amendment for 70 days. The culturing treatments were conducted in triplicate, including one treatment without earthworms as the control. The analysis showed that concentrations of macronutrients in vermicompost were higher compared to controls, in which N = 4.12%, P = 2.07% and K = 1.56%. The C:N ratio was 11.77, which indicates a stabilisation and maturity of the organic waste compost, compared with the C:N ratio for the control, which was 59.34. At the end of the experiment, increment of total biomass and number of earthworms were observed and no mortality was recorded. The results suggested that vermicomposting could be used as an environmentally valuable technology to convert saw dust used for mushroom and pea sprouts cultivation into vermicompost or bio-fertiliser by employing L. rubellus.

  2. Effects of glutamate decarboxylase and gamma-aminobutyric acid (GABA) transporter on the bioconversion of GABA in engineered Escherichia coli.

    Science.gov (United States)

    Le Vo, Tam Dinh; Kim, Tae Wan; Hong, Soon Ho

    2012-05-01

    Gamma-aminobutyric acid (GABA) is a non-essential amino acid and a precursor of pyrrolidone, a monomer of nylon 4. GABA can be biosynthesized through the decarboxylation of L: -glutamate by glutamate decarboxylase. In this study, the effects of glutamate decarboxylase (gadA, gadB), glutamate/GABA antiporter (gadC) and GABA aminotransferase (gabT) on GABA production were investigated in Escherichia coli. Glutamate decarboxylase was overexpressed alone or with the glutamate/GABA antiporter to enhance GABA synthesis. GABA aminotransferase, which redirects GABA into the TCA cycle, was knock-out mutated. When gadB and gadC were co-overexpressed in the gabT mutant strain, a final GABA concentration of 5.46 g/l was obtained from 10 g/l of monosodium glutamate (MSG), which corresponded to a GABA yield of 89.5%.

  3. Screening of lactic acid bacteria for their potential as microbial cell factories for bioconversion of lignocellulosic feedstocks

    DEFF Research Database (Denmark)

    Boguta, Anna Monika; Bringel, Francoise; Martinussen, Jan

    2014-01-01

    of lactic acid bacteria was evaluated regarding their properties with respect to the conversion of lignocellulosic feedstocks. The strains were examined for their ability to utilize xylose and arabinose as well as their resistance towards common inhibitors from pretreated lignocellulosic biomass (furan...... derivatives, phenolic compounds, weak acids). Results: Among 296 tested Lactobacillus and Pediococcus strains, 3 L. pentosus, 1 P. acidilactici and 1 P. pentosaceus isolates were found to be both capable of utilizing xylose and arabinose and highly resistant to the key inhibitors from chemically pretreated...

  4. Solid-state bioconversion of phenolics from cranberry pomace and role of Lentinus edodes beta-glucosidase.

    Science.gov (United States)

    Zheng, Z; Shetty, K

    2000-03-01

    Cranberry pomace contains large amounts of phenolic glycosides, which are important sources of free phenolics that have many food uses such as antioxidants, flavorings, and nutraceuticals. Our hypothesis was that these glycosides in cranberry pomace could be hydrolyzed by beta-glucosidase produced by Lentinus edodes during solid-state fermentation. On the basis of this hypothesis, our objective was to investigate the potential of using cranberry pomace as a substrate for the production of free phenolics and beta-glucosidase through solid-state fermentation by a food-grade fungus L. edodes. Our results suggested that L. edodes beta-glucosidase played a major role in release of phenolic aglycons from cranberry pomace during solid-state fermentation. After 50 days of cultivation, the yield of total free phenolics reached the maximum of 0.5 mg per g of pomace, while the beta-glucosidase activity was about 9 units per g of pomace. The enzyme exhibited optimal activity at 60 degrees C and at pH 3.5 and was stable at temperatures up to 50 degrees C and between pH 3 and 6.5. The major free phenolics produced from cranberry pomace were identified by HPLC as gallic acid, chlorogenic acid, p-hydroxybenzoic acid, and p-coumaric acid. These results suggest that cranberry pomace is a potential substrate for producing food-grade phenolics and fungal beta-glucosidase. The L. edodes beta-glucosidase showed good stability and tolerance to low pH and, therefore has potential applications in wine and juice processing for aroma and flavor enrichment through enzymatic hydrolysis of glucoside precursors.

  5. Bioconversion enhancement of conjugated linoleic acid by Lactobacillus plantarum using the culture media manipulation and numerical optimization.

    Science.gov (United States)

    Khosravi, Azin; Safari, Mohammad; Khodaiyan, Faramarz; Gharibzahedi, Seyed Mohammad Taghi

    2015-09-01

    The ability of different Lactobacillus strains to produce conjugated linoleic acid (CLA) from linoleic acid was evaluated. Preliminary experiments revealed that L. plantarum among the screened strains had the highest CLA-producing potential (95.25 μg/mL). The cell growth of this bacterium was studied in three media of MRS broth, skim milk and skim milk supplemented with yeast extract and glucose. Results showed that the use of yeast extract and glucose could significantly increase the cell growth and CLA production. Response surface methodology (RSM) was applied to investigate the effects of three independent variables; linoleic acid (LA), yeast extract concentrations and inoculum size on the CLA formation. A second-order polynomial model with high R (2) value (0.981) was developed using multiple linear regression analysis. The optimum conditions to achieve the highest CLA production (240.69 μg/mL) was obtained using 3 mg/mL LA, 4 g/L yeast extract and inoculum size of 4 % v/v. CLA concentration of the optimal sample was analyzed by Gas Chromatography (GC). The cis-9, trans-11 CLA was the major CLA isomer of total CLA detected.

  6. Enhancing Bioconversion Efficiency of the Earthworm Eudrilus Eugeniae (Kingberg by Fortifying the Filtermud Vermibed using an Organic Nutrient

    Directory of Open Access Journals (Sweden)

    K. Vasanthi

    2011-01-01

    Full Text Available Problem statement: Rapid urbanization and population growth are largely responsible for very high increasing rate of solid waste in the urban areas, its proper management and recycling is major problems of Municipal Corporation. Conversion of industrial wastes in to beneficial vermicompost not only solves solid waste accumulation but also yield highly nutritive organic manure. Approach: Enhancing the efficiency of earthworm that is involved in process of converting sugar mill filter press mud in to vermicompost, will be highly economical. An African earthworm Eudrilus eugeniae was used to convert the sugar mill filter press mud into nutritive vermicompost. To enhance vermicomposting efficiency, an organic nutrient preparation Jeevamirtham, an effective microbial suspension was supplemented. Results: The vermicompost yielded in Jeevamirtham supplemented vermibed had a significantly high nitrogen, phosphorus and micronutrient value. In the Jeeamirtham supplemeted vermicompost C/N ratio was 55.5% higher than that was present in the cowdung added vermicompost. In filtermud-Jeevamirtham, vermibed the mean egg production by a single worm at 45 days of growth was 12 Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} ±2.6 (33.33%. Jeevamirtham had influenced the egg production. When compared to filtermud-cowdung vermibed reared worm, (77.4% the hatchability of eggs in filtermud jeevamirtham vermibed was high (85.8%. This indicates that the jeevamirtham supplementation strengthens viability of the eggs. Conclusion: The present study recommends utilization of effective microorganism suspension, Jeevamirtham for vermicomposting to enhance the functioning of the earthworm and to increase fertilizer value of vermicompost. In the present study also macronutrient and micronutrient content increased significantly in vermicompost prepared from pressmud waste due to the supplementation of Jeevamirtham. This is practical significance if adopted by urban farmers as a result of soil health and in turn the productivity of soil can be maintained for further agriculture.

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

    DEFF Research Database (Denmark)

    Markou, Giorgos; Angelidaki, Irini; Georgakakis, Dimitris

    2012-01-01

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

  8. Vanillin - Bioconversion and Bioengineering of the most popular plant flavour and its de novo biosynthesis in the vanilla orchid.

    Science.gov (United States)

    Gallage, Nethaji J; Moeller, Birger Lindberg

    2014-09-30

    During recent years, biotechnology derived production of flavours and fragrances have expanded rapidly. The world's most popular flavour vanillin is no exception. This review outlines the current state of biotechnology-based vanillin synthesis with the use of ferulic acid, eugenol and glucose as substrates and bacteria, fungi and yeasts as microbial production hosts. The elucidated de novo biosynthetic pathway of vanillin in the vanilla orchid and the possible applied uses of this new knowledge in the biotechnology derived and pod-based vanillin industries are also highlighted.

  9. Fermentation products of solvent tolerant marine bacterium Moraxella spp. MB1 and its biotechnological applications in salicylic acid bioconversion

    Digital Repository Service at National Institute of Oceanography (India)

    Wahidullah, S.; Naik, D.N.; PrabhaDevi

    Bruker Avance AC 300 MHz instrument in deuterated chloroform (CDCl3) containing tetramethyl silane (TMS) as the internal standard. Mass spectra (ESI-MS) were acquired, in positive (+) as well as negative (2) ionization mode, using a QTOF-XL MS/MS, Applied...

  10. In vitro bioconversion of [14C]androstenedione by testes of the Siamese fighting fish Betta splendens Regan (Anabantoidei, Belontiidae).

    Science.gov (United States)

    Leitz, T; Reinboth, R

    1985-06-01

    Minced testes of the Siamese fighting fish Betta splendens were incubated with [14C]androstenedione at 27 degrees C for 15, 30, 60, and 120 min. The metabolic products were characterized by paper and thin-layer chromatography, derivative formation, and eventually by crystallization to constant specific activity. After 2 hr of incubation 80.5% of total radioactivity was converted to 11-oxygenated androgens. 11-Ketotestosterone was the main metabolite (56.2%). Our data suggest the existence of two biosynthetic pathways for the formation of 11-ketotestosterone from androstenedione. The sequence androstenedione----testosterone----11 beta-hydroxytestosterone----11-ketotestosterone predominates. To a lesser extent 11 beta-hydroxylation takes place as the first step--followed by formation of 11 beta-hydroxytestosterone and its subsequent oxidation to 11-ketotestosterone.

  11. A feasibility study on the bioconversion of CO2 and H2 to biomethane by gas sparging through polymeric membranes.

    Science.gov (United States)

    Díaz, I; Pérez, C; Alfaro, N; Fdz-Polanco, F

    2015-06-01

    In this study, the potential of a pilot hollow-fiber membrane bioreactor for the conversion of H2 and CO2 to CH4 was evaluated. The system transformed 95% of H2 and CO2 fed at a maximum loading rate of 40.2 [Formula: see text] and produced 0.22m(3) of CH4 per m(3) of H2 fed at thermophilic conditions. H2 mass transfer to the liquid phase was identified as the limiting step for the conversion, and kLa values of 430h(-1) were reached in the bioreactor by sparging gas through the membrane module. A simulation showed that the bioreactor could upgrade biogas at a rate of 25m(3)/mR(3)d, increasing the CH4 concentration from 60 to 95%v. This proof-of-concept study verified that gas sparging through a membrane module can efficiently transfer H2 from gas to liquid phase and that the conversion of H2 and CO2 to biomethane is feasible on a pilot scale at noteworthy load rates.

  12. Antioxidant properties of different edible mushroom species and increased bioconversion efficiency of Pleurotus eryngii using locally available casing materials.

    Science.gov (United States)

    Mishra, K K; Pal, R S; Arunkumar, R; Chandrashekara, C; Jain, S K; Bhatt, J C

    2013-06-01

    Total phenolics, radical scavenging activity (RSA) on DPPH, ascorbic acid content and chelating activity on Fe(2+) of Pleurotus citrinopileatus, Pleurotus djamor, Pleurotus eryngii, Pleurotus flabellatus, Pleurotus florida, Pleurotus ostreatus, Pleurotus sajor-caju and Hypsizygus ulmarius have been evaluated. The assayed mushrooms contained 3.94-21.67 mg TAE of phenolics, 13.63-69.67% DPPH scavenging activity, 3.76-6.76 mg ascorbic acid and 60.25-82.7% chelating activity. Principal Component Analysis (PCA) revealed that significantly higher total phenolics, RSA on DPPH and growth/day was present in P. eryngii whereas P. citrinopileatus showed higher ascorbic acid and chelating activity. Agglomerative hierarchical clustering analysis revealed that studied mushroom species fall into two clusters; Cluster I included P. djamor, P. eryngii and P. flabellatus, while Cluster II included H. ulmarius, P. sajor-caju, P. citrinopileatus, P. ostreatus and P. florida. Enhanced yield of P. eryngii was achieved on spent compost casing material. Use of casing materials enhanced yield by 21-107% over non-cased substrate.

  13. Bioconversion of garden waste, kitchen waste and cow dung into value-added products using earthworm Eisenia fetida.

    Science.gov (United States)

    Wani, K A; Mamta; Rao, R J

    2013-04-01

    Solid waste management is a worldwide problem and it is becoming more and more complicated day by day due to rise in population, industrialization and changes in our life style. Transformation of industrial sludges into vermicompost is of double interest: on the one hand, a waste is converted into value added product, and, on the other, it controls a pollutant that is a consequence of increasing industrialization. Garden waste, kitchen waste and cow dung were subjected to recycle through vermicomposting by using the epigeic earthworm Eisenia fetida under field conditions. The pH, moisture content, total organic carbon, humus, nitrogen, phosphorous and potassium in vermicompost was analysed. It was found that moisture content, total organic carbon, humus, nitrogen, phosphorous and potassium was high in cow dung, followed by kitchen waste and garden waste. This study clearly indicates that vermicomposting of garden waste, kitchen waste and cow dung can not only produce a value added produce (vermicomposting) but at the same time reduce the quantity of waste.

  14. An integrative process of bioconversion of oil palm empty fruit bunch fiber to ethanol with on-site cellulase production.

    Science.gov (United States)

    Zhu, Youshuang; Xin, Fengxue; Zhao, Ying; Chang, Yunkang

    2014-11-01

    The aim of this study was to efficiently convert oil palm empty fruit bunch fiber (OPEFB), one of the most commonly generated lingo-wastes in Southeast Asia, into both cellulase and bioethanol. The unprocessed cellulase crude (37.29%) produced under solid-state fermentation using OPEFB as substrate showed a better reducing sugar yield using filter paper than the commercial enzyme blend (34.61%). Organosolv pretreatment method could efficiently reduce hemicellulose (24.3-18.6%) and lignin (35.2-22.1%) content and increase cellulose content (40.5-59.3%) from OPEFB. Enzymatic hydrolysis of pretreated OPEFB using the crude cellulase with 20% solid content, enzyme loading of 15 FPU/g OPEFB at 50 °C, and pH 5.5 resulted in a OPEFB hydrolysate containing 36.01 g/L glucose after 72 h. Fermentation of the hydrolysate medium produced 17.64 g/L ethanol with 0.49 g/g yield from glucose and 0.088 g/g yield from OPEFB at 8 h using Saccharomyces cerevisiae.

  15. Large scale solubilization of coal and bioconversion to utilizable energy. Quarterly report, July 1, 1996--September 30 1996

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, N.C.

    1996-12-31

    A purification of the Neurospora protein with coal solubilization activity (CSA) using DEAE cellulose chromatography is described. The protein is heavily glycosylated suggesting that it is different than tyrosinase or common phenol oxidases even though it resembles these proteins in enzyme activity and molecular weight.

  16. Large scale solubilization of coal and bioconversion to utilizable energy. Quarterly report, October 1, 1995--December 31, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, N.C.

    1995-12-31

    The ability of Neurospora to solubilize and bioconvert coal was investigated. The coal solubilizing activity (CSA) was fractionated to isolate the enzyme responsible for this activity. The enzyme was purified in order to obtain the amino acid sequence. From that sequence potential oligonucleotide probes were synthesized and used to screen genomic library of Neurospora. The gene so identified was isolated. CSA appears to be an phenol oxidase or is tyrosinase.

  17. Bioconversion of waste office paper to gluconic acid in a turbine blade reactor by the filamentous fungus Aspergillus niger.

    Science.gov (United States)

    Ikeda, Yuko; Park, Enock Y; Okuda, Naoyuki

    2006-05-01

    Gluconic acid production was investigated using an enzymatic hydrolysate of waste office automation paper in a culture of Aspergillus niger. In repeated batch cultures using flasks, saccharified solution medium (SM) did not show any inhibitory effects on gluconic acid production compared to glucose medium (GM). The average gluconic acid yields were 92% (SM) and 80% (GM). In repeated batch cultures using SM in a turbine blade reactor (TBR), the gluconic acid yields were 60% (SM) and 67% (GM) with 80-100 g/l of gluconic acid. When pure oxygen was supplied the production rate increased to four times higher than when supplying air. Remarkable differences in the morphology of A. niger and dry cell weight between SM and GM were observed. The difference in morphology may have caused a reduction of oxygen transfer, resulting in a decrease in gluconic acid production rate in SM.

  18. Bioconversion of Coal: Hydrologic indicators of the extent of coal biodegradation under different redox conditions and coal maturity, Velenje Basin case study, Slovenia

    Science.gov (United States)

    Kanduč, Tjaša; Grassa, Fausto; Lazar, Jerneja; Jamnikar, Sergej; Zavšek, Simon; McIntosh, Jennifer

    2014-05-01

    Underground mining of coal and coal combustion for energy has significant environmental impacts. In order to reduce greenhouse gas emissions, other lower -carbon energy sources must be utilized. Coalbed methane (CBM) is an important source of relatively low-carbon energy. Approximately 20% of world's coalbed methane is microbial in origin (Bates et al., 2011). Interest in microbial CBM has increased recently due to the possibility of stimulating methanogenesis. Despite increasing interest, the hydrogeochemical conditions and mechanisms for biodegradation of coal and microbial methane production are poorly understood. This project aims to examine geochemical characteristics of coalbed groundwater and coalbed gases in order to constrain biogeochemical processes to better understand the entire process of coal biodegradation of coal to coalbed gases. A better understanding of geochemical processes in CBM areas may potentially lead to sustainable stimulation of microbial methanogenesis at economical rates. Natural analogue studies of carbon dioxide occurring in the subsurface have the potential to yield insights into mechanisms of carbon dioxide storage over geological time scales (Li et al., 2013). In order to explore redox processes related to methanogenesis and determine ideal conditions under which microbial degradation of coal is likely to occur, this study utilizes groundwater and coalbed gas samples from Velenje Basin. Determination of the concentrations of methane, carbondioxide, nitrogen, oxygen, argon was performed with homemade NIER mass spectrometer. Isotopic composition of carbon dioxide, isotopic composition of methane, isotopic composition of deuterium in methane was determined with Europa-Scientific IRMS with an ANCA-TG preparation module and Thermo Delta XP GC-TC/CF-IRMS coupled to a TRACE GC analyzer. Total alkalinity of groundwater was measured by Gran titration. Major cations were analyzed by ICP-OES and anions by IC method. Isotopic composition of dissolved inorganic carbon was determined by MultiflowBio preparation module. The stable isotope composition of sulphur was determined with a Europa Scientific 20-20 continuous flow IRMS ANCA-SL preparation module. Concentrations of tritium were determined with the electrolytic enrichment method. PHREEQC for Windows was used to perform thermodynamic modelling. The average coalbed gas composition in the coalbed seam is approximately carbon dioxide: methane > 2:1, where a high proportion of CO2 is adsorbed on the lignite structure, while methane is present free in coal fractures. It can be concluded that isotopic composition of carbon in methane from -70.4‰ to -50.0‰ is generated via acetate fermentation and via reduction of carbon dioxide, while isotopic composition of carbon in methane values range from -50.0‰ to -18.8‰, thermogenic methane can be explained by secondary processes, causing enrichment of residual methane with the heavier carbon isotope. Isotopic composition of deuterium in methane range from -343.9‰ to -223.1‰. Isotopic composition of carbon in carbon dioxide values at excavation fields range from -11.0‰ to +5‰ and are endogenic and microbial in origin. The major ion chemistry, redox conditions, stable isotopes and tritium measured in groundwater from the Velenje Basin, suggest that the Pliocene and Triassic aquifers contain distinct water bodies. Groundwater in the Triassic aquifer is dominated by hydrogen carbonate, calcium, magnesium and isotopic composition of dissolved inorganic carbon indicating degradation of soil organic matter and dissolution of carbonate minerals, similar to surface waters. In addition, groundwater in the Triassic aquifer has isotopic composition of oxygen and isotopic composition of deuterium values which plot near surface waters on the local and global meteoric water lines and detectable tritium reflects recent recharge. In contrast, groundwater in the Pliocene aquifers is enriched in magnesium, sodium, calcium, potassium, and silica and has alkalinity and isotopic composition of dissolved inorganic carbon values with low sulphate and nitrate concentrations. These waters have likely been influenced by sulfate reduction and microbial methanogenesis associated with coal seams and dissolution of feldspars and magnesium-rich clay minerals. Pliocene aquifer waters are also depleted in heavier oxygen isotope and heavier deuterium isotope and have tritium concentrations near the detection limit, suggesting these waters are older. References Bates, B.L., McIntosh J.C., Lohse K.A., Brooks P.D. 2011: Influence of groundwater flowpaths, residence times, and nutrients on the extent of microbial methanogenesis in coal beds: Powder River Basin, USA, Chemical geology, 284, 45-61. Li, W., Cheng Y., Wang L., Zhou H., Wang H., Wang L. 2013: Evaluating the security of geological coalbed sequestration of supercritical CO2 reservoirs: The Haishiwan coalfield, China as a natural analogue, International Journal of Greenhouse Gas Control, 13, 102-111.

  19. Integration of Artificial Photosynthesis System for Enhanced Electronic Energy-Transfer Efficacy: A Case Study for Solar-Energy Driven Bioconversion of Carbon Dioxide to Methanol.

    Science.gov (United States)

    Ji, Xiaoyuan; Su, Zhiguo; Wang, Ping; Ma, Guanghui; Zhang, Songping

    2016-09-01

    Biocatalyzed artificial photosynthesis systems provide a promising strategy to store solar energy in a great variety of chemicals. However, the lack of direct interface between the light-capturing components and the oxidoreductase generally hinders the trafficking of the chemicals and photo-excited electrons into the active center of the redox biocatalysts. To address this problem, a completely integrated artificial photosynthesis system for enhanced electronic energy-transfer efficacy is reported by combining co-axial electrospinning/electrospray and layer-by-layer (LbL) self-assembly. The biocatalysis part including multiple oxidoreductases and coenzymes NAD(H) was in situ encapsulated inside the lumen polyelectrolyte-doped hollow nanofibers or microcapsules fabricated via co-axial electrospinning/electrospray; while the precise and spatial arrangement of the photocatalysis part, including electron mediator and photosensitizer for photo-regeneration of the coenzyme, was achieved by ion-exchange interaction-driven LbL self-assembly. The feasibility and advantages of this integrated artificial photosynthesis system is fully demonstrated by the catalyzed cascade reduction of CO2 to methanol by three dehydrogenases (formate, formaldehyde, and alcohol dehydrogenases), incorporating the photo-regeneration of NADH under visible-light irradiation. Compared to solution-based systems, the methanol yield increases from 35.6% to 90.6% using the integrated artificial photosynthesis. This work provides a novel platform for the efficient and sustained production of a broad range of chemicals and fuels from sunlight.

  20. Anaerobic digestion of goat manure: bio-conversion of energy and bio fertilizer; Digestao anaerobica de dejetos de caprinos: conversor biologico de energia e biofertilizante

    Energy Technology Data Exchange (ETDEWEB)

    Canafistula, Francisco Jose Firmino; Carvalho, Paulo Cesar Marques de; Teixeira, Adunias dos Santos [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. Engenharia Eletrica], Emails: firmino@ufc.br, carvalho@dee.ufc.br, adunias@ufc.com

    2009-07-01

    This research aims at analyzing biogas produced by anaerobic digestion of goat excrements related to energy generation, in addition to analyzing the bio-fertilizer as a byproduct of the process. Therefore, new products are generated from semi-intensive and extensive of goats, increasing its economical and environmental viability of the activity. The biogas was applied as the fuel for an Otto cycle internal combustion engine of 5.5 HP used to drive a hydraulic pump that supplied water to an area of one hectare of pasture. In addition, the spreadsheet GDER was applied to compute the kWh cost of the following electricity sources: biogas from goat excrement, diesel, electrical grid, wind and solar. It was found tat the biogas can substitute 30% of the daily energy requirements, and one can state that 1 m{sup 3} of biogas is equivalent to 740 mL of gasoline. (author)

  1. Production of L-Lactic Acid by Bioconversion of Alkali Pretreated Corncob%碱预处理玉米芯生物转化L-乳酸

    Institute of Scientific and Technical Information of China (English)

    张丽; 陈晓佩; 李鑫; 余世袁; 勇强

    2016-01-01

    玉米芯经碱预处理后,采用米根霉对其发酵制备L-乳酸,同时考察分步糖化发酵( SHF)和同步糖化发酵( SSF)两种工艺。实验结果表明,水洗碱预处理玉米芯酶水解性能优于未水洗碱预处理玉米芯,水洗过程可显著提高米根霉发酵性能。分步糖化发酵工艺下,米根霉于40℃下发酵48 h,可将含有31.84 g/L葡萄糖、6.38 g/L木糖的酶解液转化为14.65 g/L的L-乳酸, L-乳酸得率为0.29 g/g(以绝干物料计,下同);同步糖化发酵工艺下,米根霉40℃发酵36 h将底物质量浓度为50 g/L的水洗碱预处理玉米芯高效转化为L-乳酸,L-乳酸得率为0.44 g/g。%Corncob pretreated by alkali was used as renewable raw material for L-lactic acid production by Rhizopus oryzae. The processes of separate saccharification and fermentation ( SHF) and simultaneous saccharification and fermentation ( SSF) were studied. The results showed that the enzymatic hydrolysis performance of washed alkali pretreated corncob was better than that of unwashed alkali pretreated corncob. Water-washing process could enhance the fermentability of alkali pretreated corncob. The washed alkali pretreated corncob hydrolysate with 31. 84 g/L glucose and 6. 38 g/L xylose was converted to 14. 65 g/L of L-lactic acid which was equivalent to a yield of 0. 29 g/g dry biomass with SHF process at 40 ℃ for 48 h. In contrast, a higher L-lactic acid yield (0. 44 g/g dry biomass) was achieved at 40 ℃ for 36 h, when the substrate concentration of 50 g/L washed alkali pretreated corncob was used in SFF process.

  2. Report: Bioconversion of agriculture waste to lysine with UV mutated strain of brevibacterium flavum and its biological evaluation in broiler chicks.

    Science.gov (United States)

    Tabassum, Alia; Hashmi, Abu Saeed; Masood, Faiza; Iqbal, Muhammad Aamir; Tayyab, Muhammad; Nawab, Amber; Nadeem, Asif; Sadeghi, Zahra; Mahmood, Adeel

    2015-07-01

    Lysine executes imperative structural and functional roles in body and its supplementation in diet beneficial to prevent the escalating threat of protein deficiency. The physical mutagenesis offers new fascinating avenues of research for overproduction of lysine through surplus carbohydrate containing agriculture waste especially in developing countries. The current study was aimed to investigate the potential of UV mutated strain of Brevibacterium flavum at 254 nm for lysine production. The physical and nutritional parameters were optimized and maximum lysine production was observed with molasses (4% substrate water ratio). Moreover, supplementation of culture medium with metal cations (i.e. 0.4% CaSO₄, 0.3% NaCl, 0.3% KH₂PO₄, 0.4% MgSO₄, and 0.2% (NH₄) ₂SO₄w/v) together with 0.75% v/v corn steep liquor significantly enhanced the lysine production up to 26.71 ± 0.31 g/L. Though, concentrations of urea, ammonium nitrate and yeast sludge did not exhibit any profound effect on lysine production. Biological evaluation of lysine enriched biomass in terms of weight gain and feed conversion ratio reflected non-significant difference for experimental and control (+ve) groups. Conclusively, lysine produced in the form of biomass was compatible to market lysine in its effectiveness and have potential to utilize at commercial scale.

  3. Efficient gamma-aminobutyric acid bioconversion by employing synthetic complex between glutamate decarboxylase and glutamate/GABA antiporter in engineered Escherichia coli.

    Science.gov (United States)

    Le Vo, Tam Dinh; Ko, Ji-seun; Park, Si Jae; Lee, Seung Hwan; Hong, Soon Ho

    2013-08-01

    Gamma-aminobutyric acid (GABA) is a precursor of one of the most promising heat-resistant biopolymers, Nylon-4, and can be produced by the decarboxylation of monosodium glutamate (MSG). In this study, a synthetic protein complex was applied to improve the GABA conversion in engineered Escherichia coli. Complexes were constructed by assembling a single protein-protein interaction domain SH3 to the glutamate decarboxylase (GadA and GadB) and attaching a cognate peptide ligand to the glutamate/GABA antiporter (GadC) at the N-terminus, C-terminus, and the 233rd amino acid residue. When GadA and GadC were co-overexpressed via the C-terminus complex, a GABA concentration of 5.65 g/l was obtained from 10 g/l MSG, which corresponds to a GABA yield of 93 %. A significant increase of the GABA productivity was also observed where the GABA productivity increased 2.5-fold in the early culture period due to the introduction of the synthetic protein complex. The GABA pathway efficiency and GABA productivity were enhanced by the introduction of the complex between Gad and glutamate/GABA antiporter.

  4. Pretreatment of corn stover by low moisture anhydrous ammonia (LMMA) in a pilot-scale reactor and bioconversion to fuel ethanol and industrial chemicals

    Science.gov (United States)

    Corn stover (CS) adjusted to 50%, 66% and 70% moisture was pretreated by the low moisture anhydrous ammonia (LMAA) process in a pilot-scale ammoniation reactor. After ammoniation, the 70% moisture CS was treated at 90 degree C and 100 degree C whereas the others were treated at 90 degree C only. The...

  5. Bioconversion of sawdust into ethanol using dilute sulfuric acid-assisted continuous twin screw-driven reactor pretreatment and fed-batch simultaneous saccharification and fermentation.

    Science.gov (United States)

    Kim, Tae Hyun; Choi, Chang Ho; Oh, Kyeong Keun

    2013-02-01

    Ethanol production from poplar sawdust using sulfuric acid-assisted continuous twin screw-driven reactor (CTSR) pretreatment followed by simultaneous saccharification and fermentation (SSF) was investigated. Pretreatment with high acid concentration increased the cellulose content in the pretreated solid (74.9-76.9% in the range of 4.0-5.5wt.% H(2)SO(4)). The sugar content (XMG; xylan+mannan+galactan) in the treated-solid was 11.1-15.2% and 0.9-5.7% with 0.5wt.% and 7.0wt.%, respectively. The XMG recovery yield of the sample treated with 4.0wt.% H(2)SO(4) at 185°C was maximized at 88.6%. Enzymatic hydrolysis test showed a cellulose digestibility of 67.1%, 70.1%, and 73.6% with 15, 30, and 45FPU/g-cellulose, respectively. In the fed-batch SSF tests with initial enzyme addition, the ethanol yield of each stage almost reached a maximum at 28h, 48h, and 56h, respectively, with yields of 63.9% (16.5g/L), 78.4% (30.1g/L), and 81.7% (39.9g/L), respectively.

  6. Identification of a cyclooxygenase gene from the red alga Gracilaria vermiculophylla and bioconversion of arachidonic acid to PGF(2α) in engineered Escherichia coli.

    Science.gov (United States)

    Kanamoto, Hirosuke; Takemura, Miho; Ohyama, Kanji

    2011-08-01

    Prostaglandins (PGs) are important local messenger molecules in many tissues and organs of animals including human. For applications in medicine and animal care, PGs are mostly purified from animal tissues or chemically synthesized. To generate a clean, reliable, and inexpensive source for PGs, we have now engineered expression of a suitable cyclooxygenase gene in Escherichia coli and achieved production levels of up to 2.7 mg l(-1) PGF(2α). The cyclooxygenase gene cloned from the red alga Gracilaria vermiculophylla appears to be fully functional without any eukaryotic modifications in E. coli. A crude extract of the recombinant E. coli cells is able to convert in vitro the substrate arachidonic acid (AA) to PGF(2α). Furthermore, these E. coli cells produced PGF(2α) in a medium supplemented with AA and secreted the PGF(2α) product. To our knowledge, this is the first report of the functional expression of a cyclooxygenase gene and concomitant production of PGF(2α) in E. coli. The successful microbial synthesis of PGs with reliable yields promises a novel pharmaceutical tool to produce PGF(2α) at significantly reduced prices and greater purity.

  7. Enhancing the Bioconversion of Winery and Olive Mill Waste Mixtures into Lignocellulolytic Enzymes and Animal Feed by Aspergillus uvarum Using a Packed-Bed Bioreactor.

    Science.gov (United States)

    Salgado, José Manuel; Abrunhosa, Luís; Venâncio, Armando; Domínguez, José Manuel; Belo, Isabel

    2015-10-28

    Wineries and olive oil industries are dominant agro-industrial activities in southern European regions. Olive pomace, exhausted grape marc, and vine shoot trimmings are lignocellulosic residues generated by these industries, which could be valued biotechnologically. In the present work these residues were used as substrate to produce cellulases and xylanases through solid-state fermentation using Aspergillus uvarum MUM 08.01. For that, two factorial designs (3(2)) were first planned to optimize substrate composition, temperature, and initial moisture level. Subsequently, the kinectics of cellulolytic enzyme production, fungal growth, and fermented solid were characterized. Finally, the process was performed in a packed-bed bioreactor. The results showed that cellulase activity improved with the optimization processes, reaching 33.56 U/g, and with the packed-bed bioreactor aeration of 0.2 L/min, reaching 38.51 U/g. The composition of fermented solids indicated their potential use for animal feed because cellulose, hemicellulose, lignin, and phenolic compounds were partially degraded 28.08, 10.78, 13.3, and 28.32%, respectively, crude protein was increased from 8.47 to 17.08%, and the mineral contents meet the requirements of main livestock.

  8. Effect of bioconversion conditions on vanillin production by Amycolatopsis sp. ATCC 39116 through an analysis of competing by-product formation.

    Science.gov (United States)

    Ma, Xiao-kui; Daugulis, Andrew J

    2014-05-01

    This study investigated the effects of transformation conditions such as initial pH, the initial concentration of glucose and yeast extract in the medium, and the separate addition of ferulic acid and vanillic acid, on the production of vanillin through an analysis of competing by-product formation by Amycolatopsis sp. ATCC 39116. The extent and nature of by-product formation and vanillin yield were affected by initial pH and different initial concentrations of glucose and yeast extract in the medium, with a high yield of vanillin and high cell density obtained at pH 8.0, 10 g/l glucose, and 8 g/l yeast extract. High concentrations of ferulic acid were found to negatively affect cell density. Additional supplementation of 100 mg/l vanillic acid, a metabolically linked by-product, was found to result in a high concentration of vanillin and guaiacol, an intermediate of vanillin. Via an analysis of the effect of these transformation conditions on competing by-product formation, high concentrations of ferulic acid were transformed with a molar yield to vanillin of 96.1 and 95.2 %, by Amycolatopsis sp. ATCC 39116 and Streptomyces V1, respectively, together with a minor accumulation of by-products. These are among the highest performance values reported in the literature to date for Streptomyces in batch cultures.

  9. CONTINUOUS BIOCONVERSION OF N-OCTANE TO OCTANOIC-ACID BY RECOMBINANT ESCHERICHIA-COLI (ALK+) GROWING IN A 2-LIQUID-PHASE CHEMOSTAT

    NARCIS (Netherlands)

    FAVREBULLE, O; WEENINK, E; VOS, T; PREUSTING, H; WITHOLT, B

    1993-01-01

    Escherichia coli is able to grow on sugars in the presence of a bulk n-alkane phase. When E. coli is equipped with the alk genes from Pseudomonas oleovorans, the resulting recombinant strain converts n-alkanes into the corresponding alkanoic acids. To study the effects of growth rate and exposure to

  10. Bioconversion of 2,6-dimethylpyridine to 6-methylpicolinic acid by Exophiala dermatitidis (Kano) de Hoog DA5501 cells grown on n-dodecane.

    Science.gov (United States)

    Yoshida, Toyokazu; Sada, Yuki; Nagasawa, Toru

    2010-04-01

    Alkane-assimilating microorganisms were isolated from enrichment cultures using n-octane, n-dodecane, n-hexadecane, or pristane (2,6,10,14-tetramethylpentadecane) as a sole carbon source to find microbial catalysts oxidizing methyl groups of 2,6-dimethylpyridine. The cells of Exophiala dermatitidis (Kano) de Hoog DA5501, an n-dodecane-assimilating fungus, oxidized a single methyl group of 2,6-dimethylpyridine to produce 6-methylpicolinic acid (6-methylpyridine-2-carboxylic acid) without the formation of dipicolinic acid (pyridine-2,6-dicarboxylic acid); 67 mM 6-methylpicolinic acid (9.2 g/l) accumulated with a molar conversion yield of 89% by 54-h incubation. The fungus cells also oxidized the methyl group of 2,6-dimethylpyrazine and 2,4,6-trimethylpyridine regioselectively.

  11. Fungal bioconversion of 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4-dichlorophenol (2,4-DCP).

    Science.gov (United States)

    Vroumsia, T; Steiman, R; Seigle-Murandi, F; Benoit-Guyod, J-L

    2005-09-01

    Ninety strains of fungi from the collection of our mycology laboratory were tested in Galzy and Slonimski (GS) synthetic liquid medium for their ability to degrade the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) and its by-product, 2,4-dichlorophenol (2,4-DCP) at 100 mg l(-1), each. Evolution of the amounts of each chemical in the culture media was monitored by HPLC. After 5 days of cultivation, the best results were obtained with Aspergillus penicilloides and Mortierella isabellina for 2,4-D and with Chrysosporium pannorum and Mucor genevensis for 2,4-DCP. The data collected seemed to prove, on one hand, that the strains responses varied with the taxonomic groups and the chemicals tested, and, on the other hand, that 2,4-D was less accessible to fungal degradation than 2,4-DCP. In each case, kinetics studies with the two most efficient strains revealed that there was a lag phase of 1 day before the onset of 2,4-D degradation, whereas there was none during 2,4-DCP degradation. Moreover, 2,4-DCP was detected transiently during 2,4-D degradation. Finally, M. isabellina improved its degradation potential in Tartaric Acid (TA) medium relative to GS and Malt Extract (ME) media.

  12. 乳状液膜包酶制备6-APA的研究%Preparation of 6-APA by Enzymatic Bioconversion in an Emulsion Liquid Membrane Reactor

    Institute of Scientific and Technical Information of China (English)

    陆强; 胡鸣; 熊丹柳; 邓修

    2001-01-01

    Production of 6-aminopenicillanic acid (6-APA) by hydrolysis using penicillin acylase (PA) was studied as a model of an enzymatic emulsion liquid membrane (ELM) process. The loss of PA activity was examined for various membrane compositions (organic solvent, surfactant, carrier). The effects of some experimental variables on the stability of emulsion were investigated. It was found that the choice of organic solvent greatly affected the stability of the emulsion. Increasing the concentration of the carrier in the membrane phase increases the transfer rate of substrate and products but also has a destabilizing effect on the emulsion. The recovery of 6-APA obtained by a di-carrier system (N263-N1923) was much higher than those when either of the dj-carriers was used separately. The whole process was controlled both by the enzymatic reaction rate and by the transfer rate of the substrate and the products, however, the ratio of them could be changed by varying the composition of the system. For an optimum condition, it was obtained that the recovery ratio of 6-APA was over 80% and the conversion of benzyl penicillin (PG) was up to 90% in the external phase after 30 minutes. Meanwhile, the breakage percentage of the emulsion was less than 2%.``

  13. MATHEMATICAL MODELING, AUTOMATION AND CONTROL OF THE BIOCONVERSION OF SORBITOL TO SORBOSE IN THE VITAMIN C PRODUCTION PROCESS I. MATHEMATICAL MODELING

    Directory of Open Access Journals (Sweden)

    Bonomi A.

    1997-01-01

    Full Text Available In 1990, the Biotechnology and the Control Systems Groups of IPT started developing a system for the control and automation of fermentation processes, applied to the oxidation of sorbitol to sorbose by the bacteria Gluconobacter oxydans, the microbial step of the vitamin C production process, that was chosen as a case study. Initially, a thirteen-parameter model was fitted to represent the batch operation of the system utilizing a nonlinear regression analysis, the flexible polyhedron method. Based on these results, a model for the continuous process (with the same kinetic equations was constructed and its optimum operating point obtained

  14. 啤酒酵母菌对无机硒的有机转化%Bioconversion of Inorganic Selenium into Organic Selenium by Beer Yeast (Saccharomyces cerevisiae)

    Institute of Scientific and Technical Information of China (English)

    齐秀兰; 曾红; 田洪丽; 李洋; 黄向媛; 郑歆

    2007-01-01

    利用啤酒酵母菌对无机硒(亚硒酸钠)进行有机转化.通过在培养基中加入不同浓度的无机硒溶液和不同时间加入无机硒溶液,于28℃、220r/min摇床条件下培养5d,离心得菌细胞, 测定前样品预处理:破碎菌细胞,显微镜下计数,计算破碎率,破碎后的菌体装入透析袋于蒸馏水中透析除去无机硒.准确测定无机硒,用浓硫酸-高氯酸的消化体系消化样品后,紫外分光光度法于335nm处测量吸光度,在标准曲线上查出硒含量,计算无机硒的转化率.啤酒酵母菌的最佳加硒时间为24h,亚硒酸钠浓度大于12μg/mL对啤酒酵母菌转化无机硒有明显抑制作用,啤酒酵母菌对无机硒的摄入率约为62%,转化率约为53%;超生波细胞粉碎仪破碎细胞的破碎率为55%左右.结果表明,啤酒酵母菌可以转化无机硒.

  15. Pretreatment of Corn Stover by Low Moisture Anhydrous Ammonia (LMAA) in a Pilot-Scale Reactor and Bioconversion to Fuel Ethanol and Industrial Chemicals.

    Science.gov (United States)

    Nghiem, Nhuan P; Senske, Gerard E; Kim, Tae Hyun

    2016-04-01

    Corn stover (CS) adjusted to 50, 66, and 70 % moisture was pretreated by the low moisture anhydrous ammonia (LMAA) process in a pilot-scale ammoniation reactor. After ammoniation, the 70 % moisture CS was treated at 90 and 100 °C whereas the others were treated at 90 °C only. The 70 % moisture pretreated CS then was subjected to a storage study under non-sterile conditions for 3 months. It was found that storage time did not have significant effects on the compositions of the pretreated materials and their hydrolysis by commercial enzymes. The 70 % moisture CS treated at 90 °C was used for preparation of a mix sugar hydrolysate (MSH) using combination of cellulase and xylanase. The MSH was used to prepare a corn mash at 9.5 wt% solid then subjected to ethanol fermentation by Escherichia coli KO11. The 66 % moisture CS treated at 90 °C was hydrolyzed with xylanase to make a xylose-rich hydrolysate (XRH), which was subsequently used for butyric acid fermentation by Clostridium tyrobutyricum. The resultant cellulose-enriched residue was hydrolyzed with cellulase to make a glucose-rich hydrolysate (GRH), which was subsequently used for succinic acid fermentation by E. coli AFP184.

  16. Detoxification of Olive Mill Wastewater and Bioconversion of Olive Crop Residues into High-Value-Added Biomass by the Choice Edible Mushroom Hericium erinaceus.

    Science.gov (United States)

    Koutrotsios, Georgios; Larou, Evangelia; Mountzouris, Konstantinos C; Zervakis, Georgios I

    2016-09-01

    Environmentally acceptable disposal of olive cultivation residues (e.g., olive prunings; olive pruning residues (OLPR)) and olive mill wastes is of paramount importance since they are generated in huge quantities within a short time. Moreover, olive mill wastewater (OMW) or sludge-like effluents ("alperujo"; two-phase olive mill waste (TPOMW)) are highly biotoxic. Hericium erinaceus is a white-rot fungus which produces choice edible mushrooms on substrates rich in lignocellulosics, and its suitability for the treatment of olive by-products was examined for the first time. Fungal growth resulted in a notable reduction of OMW's pollution parameters (i.e., 65 % decolorization, 47 % total phenolic reduction, and 52 % phytotoxicity decrease) and correlated with laccase and manganese peroxidase activities. Solid-state fermentation of various mixtures of OLPR, TPOMW, and beech sawdust (control) by H. erinaceus qualified OLPR in subsequent cultivation experiments, where it exhibited high mushroom yields and biological efficiency (31 %). Analyses of proximate composition and bioactive compound content revealed that mushrooms deriving from OLPR substrates showed significantly higher crude fat, total glucan, β-glucan, total phenolics, and ferric-reducing antioxidant potential values than the control. H. erinaceus demonstrated the potential to detoxify OMW and bioconvert OLPR into high-quality biomass, and hence, this fungus could be successfully exploited for the treatment of such by-products.

  17. Bioconversion of l-glutamic acid to α-ketoglutaric acid by an immobilized whole-cell biocatalyst expressing l-amino acid deaminase from Proteus mirabilis.

    Science.gov (United States)

    Hossain, Gazi Sakir; Li, Jianghua; Shin, Hyun-dong; Chen, Rachel R; Du, Guocheng; Liu, Long; Chen, Jian

    2014-01-01

    The goal of this work was to develop an immobilized whole-cell biocatalytic process for the environment-friendly synthesis of α-ketoglutaric acid (α-KG) from l-glutamic acid. We compared the suitability of Escherichia coli and Bacillus subtilis strains overexpressing Proteus mirabilisl-amino acid deaminase (l-AAD) as potential biocatalysts. Although both recombinant strains were biocatalytically active, the performance of B. subtilis was superior to that of E. coli. With l-glutamic acid as the substrate, α-KG production levels by membranes isolated from B. subtilis and E. coli were 55.3±1.73 and 21.7±0.39μg/mg protein/min, respectively. The maximal conversion ratio of l-glutamic acid to α-KG was 31% (w/w) under the following optimal conditions: 15g/L l-glutamic acid, 20g/L whole-cell biocatalyst, 5mM MgCl2, 40°C, pH 8.0, and 24-h incubation. Immobilization of whole cells with alginate increased the recyclability by an average of 23.33% per cycle. This work established an efficient one-step biotransformation process for the production of α-KG using immobilized whole B. subtilis overexpressing P. mirabilisl-AAD. Compared with traditional multistep chemical synthesis, the biocatalytic process described here has the advantage of reducing environmental pollution and thus has great potential for the large-scale production of α-KG.

  18. Bioconversion of tyrosol into hydroxytyrosol and 3,4-dihydroxyphenylacetic acid under hypersaline conditions by the new Halomonas sp. strain HTB24.

    Science.gov (United States)

    Liebgott, Pierre-Pol; Labat, Marc; Casalot, Laurence; Amouric, Agnès; Lorquin, Jean

    2007-11-01

    This paper reports the characterization of a Halomonas sp. strain (named HTB24) isolated from olive-mill wastewater and capable of transforming tyrosol into hydroxytyrosol (HT) and 3,4-dihydroxyphenylacetic acid (DHPA) in hypersaline conditions. This is the first time that a halophile has been shown to perform such reactions. The potent natural antioxidant HT was obtained through a C3 hydroxylation on the ring cycle, whereas DHPA was synthesized via the 4-hydroxyphenylacetic acid (HPA) pathway, which has been well described from other bacterial sources. HT was produced first, and then DHPA was detected in the medium accompanied by traces of HPA. HPA involved another pathway resulting from the activity of an aryl-dehydrogenase, which is suggested to be responsible for both tyrosol and hydroxytyrosol oxidation. Maximal HT content (2.30 mM) and maximal DHPA (5.15+/-0.42 mM) were obtained from a culture inoculated in the presence of 20 mM tyrosol and 0.5 g L(-1) yeast extract. Following this, DHPA was quickly degraded into 5-carboxymethyl-2-hydroxymuconic semialdehyde by a 2,3-dioxygenase, finally resulting in succinate and pyruvate. Phylogenetic analysis of the 16S rRNA gene revealed that this isolate was a member of the genus Halomonas. Strain HTB24, with a G+C content of 55.3 mol%, is closely related to Halomonas neptunia DSM 15720(T), 'Halomonas alkaliantarctica' DSM 15686(T) and Halomonas boliviensis DSM 15516(T).

  19. Large scale solubilization of coal and bioconversion to utilizable energy. Eleventh quarterly technical progress report, April 1, 1996--June 30, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, N.C.

    1996-10-01

    Neurospora has the capability to solubilize coal and the protein fraction accounting for this ability has been isolated. During this period the cola solubilizing activity (CSA) was fractionated and partially sequenced. The activity has been determined to be a tyrosinase and/or a phenol oxidase. The amino acid sequence of the protein was used to prepare oligonucleotides to identify the clone carrying Neurospora CSA. It is intended to clone the Neurospora gene into yeast, since yeast cannot solubilize coal, to further characterize the CSA.

  20. 蒸汽爆破预处理木质纤维素及其生物转化研究进展%Research Progress on the Steam Explosion Pretreatment of the Lignocellulose and Its Bioconversion

    Institute of Scientific and Technical Information of China (English)

    王堃; 蒋建新; 宋先亮

    2006-01-01

    木质纤维素生物资源可以用来生产乙醇,但其结构与化学成分阻碍了酶对纤维素的可及性,因此必须对原料进行预处理.在多种预处理方法中,蒸汽爆破法预处理因其成本低、能耗少、无污染而备受研究学者的青睐.通过对蒸汽爆破作用过程、机理和影响因素的研究分析,以及在生物转化方面的应用研究分析,更加显示出该法在此项领域广阔的前景,必将成为以木质纤维素为原料转化燃料乙醇的关键预处理技术之一.

  1. Effects of Steam Explosion Pretreatment on Bioconversion of Wheat Straw to Ethanol%蒸汽爆破预处理条件对麦草生物转化为乙醇影响的研究

    Institute of Scientific and Technical Information of China (English)

    罗鹏; 刘忠; 王高升

    2005-01-01

    以蒸汽爆破法预处理麦草,预处理温度分别为190℃和210℃,停留时间分别为2 min,4 min和8 min,研究了不同的预处理条件对麦草原料得率、半纤维素组分、纤维素的回收率、纤维素的酶水解得率的影响.结果表明:预处理条件的提高,汽爆原料的得率呈现下降趋势,而纤维素和半纤维素组分的溶解程度提高,酶水解得率相应提高.在温度为190℃,停留时间为2 min的预处理条件下,汽爆麦草原料的得率和纤维素的回收率最高,分别达到81.2%和58.4%;在温度为210℃,停留时间为8 min的预处理条件下,汽爆麦草原料的纤维分离程度最佳,并且纤维素的酶水解得率最高,达到73.2%.

  2. Influences of Steam Explosion Pretreatment for Bioconversion of Wheat Straw to Ethanol%蒸汽爆破预处理条件对麦草酶水解影响的研究

    Institute of Scientific and Technical Information of China (English)

    罗鹏; 刘忠

    2007-01-01

    在预处理温度分别为190℃和210℃,停留时间分别为2、4、8min的条件下,分析不同预处理条件对麦草原料得率、半纤维素组分、纤维素的回收率、纤维素的酶水解得率产生的影响.研究结果表明,随着预处理条件的加剧,汽爆原料的得率呈下降趋势,而纤维素和半纤维素组分的溶解程度提高,酶水解得率相应提高.在温度为190℃,停留时间为2min的条件下,汽爆麦草原料得率和纤维素回收率最高,分别达到80.7%和57.6%;在温度为210℃,停留时间为8min的条件下,汽爆麦草原料的纤维分离程度最佳,并且纤维素的酶水解得率最高,达到72.4%.

  3. Bioconversion of D-fructose to D-allose by novel isomerases%以D-果糖为原料利用新型异构酶转化生产D-阿洛糖

    Institute of Scientific and Technical Information of China (English)

    柏玮; 朱玥明; 门燕; 李晓波; 何森健; 孙媛霞

    2012-01-01

    Rare sugar is a kind of important low-energy monosaccharide that is rarely found in nature and difficult to synthesize chemically. D-allose, a six-carbon aldose, is an important rare sugar with unique physiological functions. It is radical scavenging active and can inhibit cancer cell proliferation. To obtain D-allose, the microorganisms deriving D-psicose 3-epimerase (DPE) and L-rhamnose isomerase (L-Rhl) have drawn intense attention. In this paper, DPE from Clostridium cellulolyticum H10 was cloned and expressed in Bacillus subtilis, and L-Rhl from Bacillus subtilis 168 was cloned and expressed in Escherichia coli BL21 (DE3). The obtained crude DPE and L-Rhl were then purified through a HisTrap HP affinity chromatography column and an anion-exchange chromatography column. The purified DPE and L-Rhl were employed for the production of rare sugars at last, in which DPE catalyzed D-fructose into D-psicose while L-Rhl converted D-psicose into D-allose. The conversion of D-fructose into D-psicose by DPE was 27.34%, and the conversion of D-psicose into D-allose was 34.64%.%稀少糖是自然界中含量稀少、化学合成困难的一类低热量单糖.D-阿洛糖是一种重要的稀少己醛糖,其具有减少活性自由基、抑制癌细胞增殖等独特的生理学功能.因此,以微生物发酵生产D-阿洛酮糖-3-差向异构酶(DPE)和L-鼠李糖异构酶(L-RhI)转化生产D-阿洛糖,成为近几年来国际研究的热点之一.文中分别克隆了来源于解纤维梭菌Clostridium cellulolyticum H10的DPE基因以及来源于枯草芽胞杆菌Bacillus subtilis 168的L-RhI基因,并分别使其在宿主菌B.subtilis及大肠杆菌Escherichia coli BL21 (DE3)中得到了表达.进一步利用镍亲和层析和阴离子交换色谱等手段对这两种酶进行了纯化,并对这两种纯化后酶的转化能力进行了分析测定.结果表明,以D-果糖为原料利用两种异构酶依次转化获得D-阿洛酮糖及D-阿洛糖,其两步转化效率分别为27.34%和34.64%.

  4. 微生物转化淀粉废水制备生物灭蚊剂%Bioconversion of starch processing wastewater to mosquito biolarvicides by Bacillus thuringiensis subsp. israelensis and Bacillus sphaericus

    Institute of Scientific and Technical Information of China (English)

    雷发懋; 卢娜; 王跃强; 周顺桂; 王颖

    2008-01-01

    采用摇瓶发酵试验探讨了淀粉废水为原料制备微生物灭蚊剂的可行性.结果表明,无需任何预处理工序,淀粉废水可作为微生物灭蚊菌株(Bacillus thuringiensis subsp. israelensis 187菌株和Bacillus sphaericus 2362菌株)的优良发酵培养基.Bti 187和Bs 2362菌株能在淀粉废水(含固率2.5%)为唯一原料的培养基中正常生长发育,并且产孢产毒.Bti 187和Bs 2362在淀粉废水发酵42 h,活菌数分别可达7.5×108、4.5×108 CFU·mL-1;抗热性芽孢数分别可达5.1×108、2.7×108 CFU·mL-1,均显著高于常规LB培养基.与LB培养基相比,淀粉废水培养基有利于提高芽孢产率、缩短发酵周期.毒力测定表明,淀粉废水培养42 h的Bti发酵液对淡色库蚊和白纹伊蚊的LC50分别为0.78、0.87 μg·mL-1,淀粉废水培养42 h的Bs发酵液对淡色库蚊和白纹伊蚊的LC50分别为0.70、16.06 μg·mL-1,淀粉废水明显有利于Bti 187与Bs 2362菌株的产毒.本研究不仅为淀粉废水提供了高附加值的处置新途径,而且可显著降低生物灭蚊剂的生产成本,具有广阔的应用前景.

  5. 青贮对柳枝稷制取燃料乙醇转化过程的影响%Effect of ensilage on bioconversion of switchgrass to ethanol based on liquid hot water pretreatment

    Institute of Scientific and Technical Information of China (English)

    吴文韬; 鞠美庭; 刘金鹏; 刘博群

    2016-01-01

    青贮是一种传统的生物质原料保存方法,广泛应用于纤维素乙醇炼制领域尚需要考察其对原料品质和下游乙醇转化过程的影响.文中以秋季(初、中和末)收割的柳枝稷为原料,通过青贮、高温水热(LHW)预处理、纤维素酶水解和同步糖化与发酵(SSF)实验对上述问题予以回答.结果显示,秋季初收割的柳枝稷以不同湿度青贮后pH均小于4.0,干重损失小于2%,各主要成分与青贮前相比无明显变化;LHW预处理中青贮样品半纤维素水解率普遍高于未贮存样品,但青贮同样使原料获得了更高的发酵抑制物产生水平;青贮柳枝稷葡萄糖、木糖和半乳糖产量(预处理+酶水解)高于未贮存柳枝稷;经过168 h的SSF,青贮样品乙醇浓度为12.1g/L,未贮存的秋季初、秋季中和秋季末柳枝稷为底物的浓度分别为10.3g/L、9.7g/L和10.6g/L.综上,青贮有助于提高柳枝稷LHW预处理效率、酶水解率和乙醇产量.

  6. Effects of organic substance mixing ratios on methane bioconversion through high-solids anaerobic co-fermentation%有机成分比例对高固体浓度厌氧发酵产甲烷的影响

    Institute of Scientific and Technical Information of China (English)

    赵云飞; 刘晓玲; 李十中; 阮文权; 刘建双; 田梦

    2012-01-01

    在12%高固体质量分数和中温(35±1)℃条件下,开展了碳水化合物、蛋白质和脂肪不同比例联合厌氧发酵对产气性能和有机质降解过程影响的研究.结果表明,当3种有机质比例为55∶36∶9时,每gVS最大产甲烷量、最大比产甲烷速率、实际甲烷产率分别为404.1 mL/gVS、11.2mL/(gVS·d)和326.7mL/gVS,皆高于其他有机质比例,并且有机质的降解过程更为高效、稳定.适当添加碳水化合物一方面能够提升自身的降解率,另一方面促使蛋白质和脂肪的进一步降解.当碳水化合物质量百分比高于65%时,总酸、单酸和分子态酸浓度的增加成为发酵过程的抑制因素.蛋白质质量百分比越高,发酵启动时间和发酵周期相应延长,其质量百分比高于48%时,总氨氮和游离氨对产甲烷过程造成一定抑制作用.%Evaluation of high-solids anaerobic co-fermentation of carbohydrate, protein and lipid at various mixing ratios was conducted at mesophilic (35℃ ± l℃) and high-solids (12% total solids) condition. The effects of mixing ratios on methane conversion and degradation efficiency of organic substance were investigated. Results showed that the maximum values of specific methane production potential (P5), specific methane production rate (Rs) and methane yield were all achieved at mixing ratio of 55:36:9, and they increased to 404.1mL/gVS, 11.2mL/(gVSd), and 326.7mL/gVS, respectively. Compared with other mixing ratios, the degradation process of oragnic substance was also more effective and more stable at the ratio of 55:36:9. Adding appropriate carbohydrate could not only enchance the degradation itself, but also improve the degradation efficiency of protein and lipid. Moreover, it was found that when carbohydrate in the substrate accounted for more than 65%, the high concentration of total volatile fatty acid (VFA), some single VFA and total undissociated acid became the primary factors resulting in methane production inhibition. Increasing the proportion of protein could lead to the prolonged star-up period as well as fermentation time. When protein increased up to 48%, a switch to the inhibition of methane production by total ammonia (TNH3-N) and free ammonia (NH3-N) occurred.

  7. PEG-modified Penicillin Acylase and Its Partitioning in Aqueous Two-phase Bioconversion System%PEG修饰青霉素酰化酶及其在两水相生物转化体系中的分配

    Institute of Scientific and Technical Information of China (English)

    何汉平; 刘叶青; 曹学君; 张秀萍

    2001-01-01

    Polyethyleneglycol (PEG) activated by tosyl chloride was used to modify penicillin acylase (PAC). The stability of the PEG-PAC was much better than the free PAC. The activity of the modified enzyme was 75% of free enzyme. The partition of PEG-PAC in aqueous two-phase system was investigated. The modified penicillin acylase was mainly present in the PEG phase in a PEG-dextran aqueous two-phase system, and the partition coefficient was 25.%采用对甲苯磺酰氯法,用聚乙二醇对青霉素酰化酶进行化学修饰,修饰酶的比活为未修饰酶的75%,稳定性比游离酶有了很大提高。酶在带修饰酶的聚乙二醇与葡聚糖组成的两水相体系中的分配系数为25。

  8. 代谢甘油高产乳酸的菌种选育及培养基优化%Strain Screening for Bioconversion of Glycerol to Lactic Acid and Optimization of Culture Medium

    Institute of Scientific and Technical Information of China (English)

    洪安安; 程可可; 孙燕; 陈珍; 彭枫; 刘灿明; 刘德华

    2009-01-01

    分离出一株可高效利用甘油生产乳酸的菌株,经过生理生化和16S rDNA分子鉴定,确定其属于大肠埃希氏菌,命名为Escherichia coli AC-521.通过五因素四水平正交试验,优化了其最佳发酵培养基成分为初始甘油70 g/L,酵母粉4 g/L,蛋白胨7 g/L,(NH4)2SO4 10g/L,K2HPO4 2.5 g/L.利用该最佳条件的5 L发酵罐批式补料发酵实验表明:该菌株发酵80 h后,乳酸产量可达到74.5 g/L,得率为0.87 mol/mol甘油.

  9. Reliability Analysis about Technology for Using Black Soldier Fly on Bioconversion from Food Waste to Entomic Protein%黑水虻生物处置餐厨废弃物的技术可行性分析

    Institute of Scientific and Technical Information of China (English)

    安新城

    2016-01-01

    黑水虻Hermetia illucens是为数不多的几种能够取食餐厨垃圾的动物之一,近几年日益受到国际国内研究者的关注,并在城市固体有机废弃物处置领域中被寄予厚望,本文从技术原理、市场需求、养殖模式、盈利能力、市场前景等角度对黑水虻处置餐厨垃圾的技术应用进行了全方位分析。研究认为黑水虻的生物转化技术可能是解决我国餐厨垃圾末端处置困境的最终方案,并可带动中国昆虫产业的快速发展。%Black soldier fly ( BSF) , Hermetia illucens, was regarded as one of few insect species who can digest food waste without much difficulty, which were particularly helpful on disposal of organic garbage for municipal administration, and thus BSF have been obtained more and more attention from academic, social even enterprise in the past 10 years�The analysis was done on technological reliability, market demand, profit ability and expansion model and so on, and results indicated that BSF possibly supply an important opportunity for progress of insectival protein industry, meanwhile also being last and best chance for Chinese food waste disposal on environmental protection side.

  10. Bioconversion of red ginseng saponins in the gastro-intestinal tract in vitro model studied by high-performance liquid chromatography-high resolution Fourier transform ion cyclotron resonance mass spectrometry

    NARCIS (Netherlands)

    Kong, H.; Wang, M.; Venema, K.; Maathuis, A.; Heijden, R. van der; Greef, J. van der; Xu, G.; Hankemeier, T.

    2009-01-01

    A high-performance liquid chromatography-high resolution Fourier transform ion cyclotron resonance mass spectrometry (HPLC-FTICR-MS) method was developed to investigate the metabolism of ginsenosides in in vitro models of the gastro-intestinal tract. The metabolites were identified by high-resolutio

  11. Optimization of diterpenes bioconversion process by the fungus Cephalosporium aphidicola Otimização do processo de bioconversão de compostos diterpênicos pelo fungo Cephalosporium aphidicola

    Directory of Open Access Journals (Sweden)

    Jacqueline Aparecida Takahashi

    2000-06-01

    Full Text Available Parameters for a more efficient biotransformation of diterpene-like compounds by the fungus Cephalosporium aphidicola were established by carrying out microscale feedings at several conditions. Experiments were guided by thin layer chromatography and gas chromatography analysis. It was observed that the substrate should be added in ethanol at concentrations between 15 to 30 mg per 100 ml of medium. The extraction of the product showed to be more efficient when carried out from both mycelia and broth and using ethylacetate as the extracting solvent. The experiment should be stopped six days after feeding the substrate to the fungus for the best product yield.Condições otimizadas para a biotransformação de compostos diterpênicos pelo fungo Cephalosporium aphidicola foram determinadas, realizando-se incubações em microescala nas quais variaram-se parâmetros como o tempo de incubação e a quantidade de substrato adicionado. A velocidade (índice de bioconversão foi monitorada analisando-se os extratos de cultivo através de cromatografia em camada delgada e cromatografia gasosa. Os resultados obtidos mostraram que, para melhores rendimentos, o substrato deve ser adicionado em solução etanólica, na concentração de 15-30 mg por 100 mL de meio de cultura. A extração de produtos deve ser realizada com acetato de etila, a partir da fase aquosa e do micélio, no sexto dia após a adição do substrato. Estes resultados podem ser utilizados como um roteiro para incubações de compostos estruturalmente semelhantes com o fungo Cephalosporium aphidicola.

  12. A system for accurate on-line measurement of total gas consumption or production rates in microbioreactors

    NARCIS (Netherlands)

    Leeuwen, van Michiel; Heijnen, Joseph J.; Gardeniers, Han; Oudshoorn, Arthur; Noorman, Henk; Visser, Jan; Wielen, van der Luuk A.M.; Gulik, van Walter M.

    2009-01-01

    A system has been developed, based on pressure controlled gas pumping, for accurate measurement of total gas consumption or production rates in the nmol/min range, applicable for on-line monitoring of bioconversions in microbioreactors. The system was validated by carrying out a bioconversion with k

  13. Acoustic chemometric prediction of total solids in bioslurry

    DEFF Research Database (Denmark)

    Ihunegbo, Felicia; Madsen, Michael; Esbensen, Kim

    2012-01-01

    Dry matter is an important process control parameter in the bioconversion application field. Acoustic chemometrics, as a Process Analytical Technology (PAT) modality for quantitative characterisation of dry matter in complex bioslurry systems (biogas fermentation), has not been successful despite...

  14. Digital image processing based identification of nodes and internodes of chopped biomass stems

    Science.gov (United States)

    Chemical composition of biomass feedstock is an important parameter for optimizing the yield and economics of various bioconversion pathways. Although understandably, the chemical composition of biomass varies among species, varieties, and plant components, there is distinct variation even among ste...

  15. Progress in Steam-explosion Pretreatment Technologies and Its Effect on Bioconversion of Cellulosic Ethanol%蒸汽爆破预处理技术及其对纤维乙醇生物转化的研究进展

    Institute of Scientific and Technical Information of China (English)

    王鑫

    2010-01-01

    由于木质纤维素复杂结构及纤维素结晶的特点,需要合适的预处理方法增加纤维素对酶分子的可及性.蒸汽爆破法因其低成本、无污染、能耗低等优点近年来备受关注.本文介绍了蒸汽爆破及其影响因素,在此基础上,着重讨论了几种常见的蒸汽爆破技术如稀酸蒸爆技术、稀碱蒸爆技术、氨纤维爆破技术及组合蒸爆技术等以及蒸爆设备,同时介绍了蒸汽爆破在纤维乙醇生物转化过程中的应用研究.

  16. Evaluation of the hepatic bioconversion of α-linolenic acid (ALA) to eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in rats fed with oils from chia (Salvia hispánica) or rosa mosqueta (Rosa rubiginosa)

    OpenAIRE

    Tapia O., G.; Valenzuela B., A.; Cornejo Z., P.; Vizcarra, M.; Masson S., L.; Gormáz, J. G.; Valenzuela B., R.

    2012-01-01

    The high dietary intake of n-6 fatty acids in relation to n-3 fatty acids generates health disorders, such as cardiovascular diseases, inflammatory diseases and other chronic diseases. The consumption of fish, which is rich in n-3 fatty acids, is low in Latin America and it is necessary to seek other alternatives, such as chia oil (CO) or rosa mosqueta oil (RMO), which are rich in α-linolenic acid (ALA), the precursor of the n -3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic ac...

  17. Enzymatic Synthesis of Galactosylated Serine/Threonine Derivatives by β-Galactosidase from Escherichia coli

    Directory of Open Access Journals (Sweden)

    Sooyoun Seo

    2015-06-01

    Full Text Available The transgalactosylations of serine/threonine derivatives were investigated using β-galactosidase from Escherichia coli as biocatalyst. Using ortho-nitrophenyl-β-D-galactoside as donor, the highest bioconversion yield of transgalactosylated N-carboxy benzyl L-serine benzyl ester (23.2% was achieved in heptane:buffer medium (70:30, whereas with the lactose, the highest bioconversion yield (3.94% was obtained in the buffer reaction system. The structures of most abundant galactosylated serine products were characterized by MS/MS. The molecular docking simulation revealed that the binding of serine/threonine derivatives to the enzyme’s active site was stronger (−4.6~−7.9 kcal/mol than that of the natural acceptor, glucose, and mainly occurred through interactions with aromatic residues. For N-tert-butoxycarbonyl serine methyl ester (6.8% and N-carboxybenzyl serine benzyl ester (3.4%, their binding affinities and the distances between their hydroxyl side chain and the 1′-OH group of galactose moiety were in good accordance with the quantified bioconversion yields. Despite its lower predicted bioconversion yield, the high experimental bioconversion yield obtained with N-carboxybenzyl serine methyl ester (23.2% demonstrated the importance of the thermodynamically-driven nature of the transgalactosylation reaction.

  18. A microbial transformation using Bacillus subtilis B7-S to produce natural vanillin from ferulic acid.

    Science.gov (United States)

    Chen, Peng; Yan, Lei; Wu, Zhengrong; Li, Suyue; Bai, Zhongtian; Yan, Xiaojuan; Wang, Ningbo; Liang, Ning; Li, Hongyu

    2016-02-04

    Bacillus subtilis strain B7-S screened from18 strains is an aerobic, endospore-forming, model organism of Gram-positive bacteria which is capable to form vanillin during ferulic acid bioconversion. The bioconversion of ferulic acid to vanillin by Bacillus subtilis B7-S (B. subtilis B7-S) was investigated. Based on our results, the optimum bioconversion conditions for the production of vanillin by B. subtilis B7-S can be summarized as follows: temperature 35 °C; initial pH 9.0; inoculum volume 5%; ferulic acid concentration 0.6 g/L; volume of culture medium 20%; and shaking speed 200 r/min. Under these conditions, several repeated small-scale batch experiments showed that the maximum conversion efficiency was 63.30% after 3 h of bioconversion. The vanillin products were confirmed by spectral data achieved from UV-vis, inductively coupled plasma atomic emission spectroscope (ICP-AES) and Fourier transform infrared spectrometer (FT-IR) spectra. Scanning electron microscopy (SEM) and transmission electron spectroscopy (TEM) results confirmed that the cell surface of B. subtilis plays a role in the induction of ferulic acid tolerance. These results demonstrate that B. subtilis B7-S has the potential for use in vanillin production through bioconversion of ferulic acid.

  19. Waktu Optimum Biokonversi Spontan Biji Asam Guna Meningkatkan Kandungan Nilai Gizinya Sebagai Pakan Ternak Alternatif (OPTIMUM TIME OF SPONTANEOUS FERMENTATION TO NUTRIENT VALUE OF TAMARIND SEED AS ALTERNATIF FEED

    Directory of Open Access Journals (Sweden)

    Redempta Wea

    2015-05-01

    Full Text Available The aim of this research is to evaluate nutrition value and optimum time of spontaneous bioconversionof tamarind seed. This research was conducted using complete random design experimental methodswith five bioconversion time treatments ie R0 0 hour; R1 24 hours; R2 48 hours; R3 72 hours; and R4 96hours respectively and each treatment consist of four replications. The data were then analysis usingvariants analysis and Duncan’s test. The research variable was nutrition value of tamarind seed spontaneousbioconversion. Results showed that spontaneous bioconvertion was not effecting to dry matter, crude fiber,and crude fat but effected to ash, crude protein, and metabolism energy and the best treatment wasspontaneous bio-conversion until 72 hours and make decreasing at 96 hours treatment Based on thoseresult, for getting the best result,it is suggesting to use spontaneous bioconversion until 72 hours.

  20. Biotechnology of indirect liquefaction: Progress report, April 1--June 30, 1988

    Energy Technology Data Exchange (ETDEWEB)

    Datta, R.; Grethlein, H.; Jain, M.; Worden, M.; Zeikus, J.G.

    1988-01-01

    This project on indirect liquefaction of coal derived synthesis gas will focus on two stage anaerobic bioconversion. The first stage will address bioconversion of synthesis gas (CO, H/sub 2//CO/sub 2/) to volatile fatty acids by a CO adapted strain of Butyribacterium methylotrophicum. The second stage will address bioconversion of fatty acids to combustible solvents -- acetone butanol and ethanol by a strain of Clostridium acetobutylicum. The project began at MBI when the final contract was awarded on March 17, 1988. The initial tasks of the project are: Task la -- develop chemostat fermentation for syngas conversion by B. methylotrophicum and Task 2a -- produce biocatalysts (C. acetobutylicum) for second stage solvent-fuel synthesis. A multidisciplinary team of microbiologists and engineers has been put together to work on this project. Both tasks are progressing well. 5 refs., 4 figs., 1 tab.

  1. Enzymes and microorganisms in food industry waste processing and conversion to useful products: a review of the literature

    Energy Technology Data Exchange (ETDEWEB)

    Carroad, P.A.; Wilke, C.R.

    1976-12-01

    Bioconversion of food processing wastes is receiving increased attention with the realization that waste components represent an available and utilizable resource for conversion to useful products. Liquid wastes are characterized as dilute streams containing sugars, starches, proteins, and fats. Solid wastes are generally cellulosic, but may contain other biopolymers. The greatest potential for economic bioconversion is represented by processes to convert cellulose to glucose, glucose to alcohol and protein, starch to invert sugar, and dilute waste streams to methane by anaerobic digestion. Microbial or enzymatic processes to accomplish these conversions are described.

  2. Population-based nutrikinetic modeling of polyphenol exposure

    NARCIS (Netherlands)

    van Velzen, E.J.J.; Westerhuis, J.A.; Grün, C.H.; Jacobs, D.M.; Eilers, P.H.C.; Mulder, Th.P.; Foltz, M.; Garczarek, U.; Kemperman, R.; Vaughan, E. E.; van Duynhoven, J.P.M.; Smilde, A.K.

    2014-01-01

    The beneficial health effects of fruits and vegetables have been attributed to their polyphenol content. These compounds undergo many bioconversions in the body. Modeling polyphenol exposure of humans upon intake is a prerequisite for understanding the modulating effect of the food matrix and the co

  3. Population-based nutrikinetic modelling of phytochemical exposure

    NARCIS (Netherlands)

    Velzen, van E.J.J.; Westerhuis, J.A.; Grün, C.H.; Duynhoven, van J.P.M.; Jacobs, D.M.; Eilers, P.H.C.; Mulder, T.P.; Foltz, M.; Garczarek, U.; Kemperman, R.; Vaughan, E.E.; Smilde, A.K.

    2014-01-01

    The beneficial health effects of fruits and vegetables have been attributed to their polyphenol content. These compounds undergo many bioconversions in the body. Modeling polyphenol exposure of humans upon intake is a prerequisite for understanding the modulating effect of the food matrix and the co

  4. CE-LIF-MSn profiling of oligosaccharides in human milk and feces of breast-fed babies

    NARCIS (Netherlands)

    Albrecht, S.A.; Schols, H.A.; Heuvel, van den E.G.H.M.; Voragen, A.G.J.; Gruppen, H.

    2010-01-01

    Mixtures of the complex human milk oligosaccharides (HMOs) are difficult to analyze and gastrointestinal bioconversion products of HMOs may complicate analysis even more. Their analysis, therefore, requires the combination of a sensitive and high-resolution separation technique with a mass identific

  5. Mary Elizabeth Hickox Mandels, 90, bioenergy leader

    Directory of Open Access Journals (Sweden)

    Eveleigh Douglas E

    2009-09-01

    Full Text Available Abstract Mary E H Mandels, who spearheaded the US Army's national bioconversion studies for four decades and was an early proponent of conversion of waste biomass to readily bioconvertible sugars for the production of chemicals and transportation fuels such as ethanol, died 17 February 2008 at Natick, MA, USA. She was 90.

  6. Studies on the incorporation of lipase in synthetic polymerisable vesicles.

    NARCIS (Netherlands)

    Mosmuller, E.W.J.

    1993-01-01

    This thesis describes studies on the suitability of synthetic polymerisable vesicles for the incorporation and stabilisation of lipase for the bioconversion of organic chemical compounds.In chapter 1 , some characteristics are reviewed of hydrolytic enzymes, and more specific those

  7. Regulation of expression of the Aspergillus niger benzoate para-hydroxylase cytochrome P450 system

    NARCIS (Netherlands)

    Brink, J.M. van den; Punt, P.J.; Gorcom, R.F.M. van; Hondel, C.A.M.J.J. van den

    2000-01-01

    Cytochrome P450 enzyme systems are found throughout nature and are involved in many different, often complex, bioconversions. In the endoplasmic reticulum of the filamentous fungus Aspergillus niger a cytochrome P450 enzyme system is present that is capable of the para-hydroxylation of benzoate. The

  8. Utilization of geothermal energy for methane production for J. A. Albertson Land and Cattle Company. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1980-07-01

    The feasibility of an integrated system to utilize a geothermal resource for a bioconversion plant. This integrated facility would use the manure from approximately 30,000 head of feedlot cattle as a feedstock for an anaerobic digestion plant. The findings on engineering design, geological assessment, environmental, economic, and institutional requirements of the proposed project are summarized. (MHR)

  9. Enzymatic hydrolysis of cocoa pod husks. [Trichoderma reesei

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, B.K.; Oldham, J.H.; Martin, A.M

    1984-07-01

    Laboratory results are presented of the bioconversion of cellulose from cocoa pod husks, utilizing cellulase from three mutants of Trichoderma reesei. Total reducing sugars in filtered hydrolysates were estimated by the dinitrosalicylic acid method. The sugars present were identified by paper chromatography as glucose and xylose.

  10. Biological conversion system

    Science.gov (United States)

    Scott, C.D.

    A system for bioconversion of organic material comprises a primary bioreactor column wherein a biological active agent (zymomonas mobilis) converts the organic material (sugar) to a product (alcohol), a rejuvenator column wherein the biological activity of said biological active agent is enhanced, and means for circulating said biological active agent between said primary bioreactor column and said rejuvenator column.

  11. Enzyme nanoassemblies for biomass conversion

    Science.gov (United States)

    Biomass represents a vast resource for the production of the world’s fuel and chemical feedstock needs. The use of enzymes to effect these bioconversions offers an alternative that is potentially more specific and environmentally-friendly than harsher chemical methodologies. Some species of anaero...

  12. Cell Wall Diversity in Forage Maize

    NARCIS (Netherlands)

    Torres, A.F.; Noordam-Boot, C.M.M.; Dolstra, Oene; Weijde, van der Tim; Combes, Eliette; Dufour, Philippe; Vlaswinkel, Louis; Visser, R.G.F.; Trindade, L.M.

    2015-01-01

    Genetic studies are ideal platforms for assessing the extent of genetic diversity, inferring the genetic architecture, and evaluating complex trait interrelations for cell wall compositional and bioconversion traits relevant to bioenergy applications. Through the characterization of a forage maiz

  13. Military Wastes-to-Energy Applications,

    Science.gov (United States)

    1980-11-01

    percent) Pyrolysis characterization Protein nitrogen Toxicity Phosphorus Corrosivity Lipids Explosivity Starches Other safety factors Sugars Biological...synthetics. Leather, rubber Shoes, tires , toys. Food waste Wet garbage, unidentifiable mixture. Yards and grounds Twigs and green branches, grass and...61). The following conversion process categories will be described and ana- lyzed: combustion, pyrolysis , and bioconversion. Appropriate systems within

  14. Insertion of Cecropin A and reconstitution of bacterial outer membrane protein FhuA variants in polymeric membranes

    OpenAIRE

    Muhammad, Noor

    2011-01-01

    Polymer based nanocompartments (polymersomes) have potential applications in synthetic biology (pathway engineering), medicine (drug release), and industrial biotechnology (chiral nanoreactors, multistep synthesis, bioconversions in non-aqueous environments, and selective product recovery). The aforementioned goals can be accomplished by polymer membrane functionalization through covalent bonding or inclusion of proteins/peptides, to obtain specific properties like recognition, catalytic acti...

  15. Increased NADPH concentration obtained by metabolic engineering of the pentose phosphate pathway in Aspergillus niger

    NARCIS (Netherlands)

    Poulsen, B.R.; Nohr, J.; Douthwaite, S.; Hansen, L.V.; Iversen, J.J.L.; Visser, J.; Ruijter, G.J.G.

    2005-01-01

    Many biosynthetic reactions and bioconversions are limited by low availability of NADPH. With the purpose of increasing the NADPH concentration and/or the flux through the pentose phosphate pathway in Aspergillus niger, the genes encoding glucose 6-phosphate dehydrogenase (gsdA), 6-phosphogluconate

  16. Nanostructure enzyme assemblies for biomass conversion

    Science.gov (United States)

    Biomass represents a vast resource for production of the world’s fuel and chemical feedstock needs. The use of enzymes to effect these bioconversions offers an alternative that is potentially more specific and environmentally-friendly than harsher chemical methodologies. Some species of anaerobic ...

  17. Effects of Surfactant on Solubility and Microbial Conversion of Steroid

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Enhancing the dispersion and dissolution of substrate particles in substrate/water suspension is a feasible way to improve steroid bioconversion. The aim of the present study is to investigate the effects of applying surfactant to microbial conversion system on the dispersion, solubilization and in turn bioconversion of steroid substrate. The model system is hydroxylation of substrate 16α-,17α-epoxy-4-pregnene-3,20-dine by microbial enzymes from Rhizopus nigricanl. The results show that the presence of substrate leads to an increase in critical micelle concentration (CMC) of surfactant PSE compared with the normal CMC of PSE in aqueous solution. The grinding time during substrate suspension preparation affects the substrate aqueous solubility differently with the varied surfactant concentrations while barely making any difference in substrate solubility in the absence of surfactant. The properly prolonged grinding time can make up for the loss in substrate solubility arising from the reduction in surfactant concentration. The surfactant complexes composed of surfactants PSE and MGE at appropriate ratios are screened out with orthodoxy experiment method, the interaction between PSE and MGE exerts the most prominent effects on substrate bioconversion, and the surfactant complexes show more beneficial effects on steroid bioconversion than the surfactant PSE used alone.

  18. Biocatalytic material comprising multilayer enzyme coated fiber

    Science.gov (United States)

    Kim, Jungbae [Richland, WA; Kwak, Ja Hun [Richland, WA; Grate, Jay W [West Richland, WA

    2009-11-03

    The present invention relates generally to high stability, high activity biocatalytic materials and processes for using the same. The materials comprise enzyme aggregate coatings having high biocatalytic activity and stability useful in heterogeneous environment. These new materials provide a new biocatalytic immobilized enzyme system with applications in bioconversion, bioremediation, biosensors, and biofuel cells.

  19. Recombinant Saccharomyces cerevisiae expressing P450 in artificial digestive systems : A model for biodetoxication in the human digestive environment

    NARCIS (Netherlands)

    Blanquet, S.; Meunier, J.P.; Minekus, M.; Marol-Bonnin, S.; Alric, M.

    2003-01-01

    The use of genetically engineered microorganisms such as bacteria or yeasts as live vehicles to carry out bioconversion directly in the digestive environment is an important challenge for the development of innovative biodrugs. A system that mimics the human gastrointestinal tract was combined with

  20. Lignocellulosic biomass utilization toward biorefinery using meshophilic Clostridial species

    NARCIS (Netherlands)

    Tamaru, Yutaka; Lopez Contreras, A.M.

    2013-01-01

    Lignocellulosic biomass such as agricultural, industrial, and forestry residues as well as
    dedicated crops constitute renewable and abundant resources with great potential for a lowcost
    and uniquely sustainable bioconversion to value-added bioproducts. Thus, many
    organic fuels and chemic

  1. Toxicity of terpenes to spores and mycelium of Penicillium digitatum

    NARCIS (Netherlands)

    Wolken, W.A.M.; Tramper, J.; Werf, M.J. van der

    2002-01-01

    Spores, although often considered metabolically inert, catalyze a variety of reactions. The use of spores instead of mycelium for bioconversions has several advantages. In this paper, we describe the difference in susceptibility of mycelium and spores against toxic substrates and products. A higher

  2. Toxicity of terpenes to spores and mycelium op Penicillium digitatum

    NARCIS (Netherlands)

    Wolken, W.A.M.; Tramper, J.; Werf, van der M.J.

    2002-01-01

    Spores, although often considered metabolically inert, catalyze a variety of reactions. The use of spores instead of mycelium for bioconversions has several advantages. In this paper, we describe the difference in susceptibility of mycelium and spores against toxic substrates and products. A higher

  3. Impact of Diet on Human Intestinal Microbiota and Health

    NARCIS (Netherlands)

    Salonen, A.; Vos, de W.M.

    2014-01-01

    Our intestinal microbiota is involved in the breakdown and bioconversion of dietary and host components that are not degraded and taken up by our own digestive system. The end products generated by our microbiota fuel our enterocytes and support growth but also have signaling functions that generate

  4. Biotransformation of Domestic Wastewater Treatment Plant Sludge by Two-Stage Integrated Processes -Lsb & Ssb

    Directory of Open Access Journals (Sweden)

    Md. Zahangir Alam, A. H. Molla and A. Fakhru’l-Razi

    2012-10-01

    Full Text Available The study of biotransformation of domestic wastewater treatment plant (DWTP sludge was conducted in laboratory-scale by two-stage integrated process i.e. liquid state bioconversion (LSB and solid state bioconversion (SSB processes. The liquid wastewater sludge [4% w/w of total suspended solids (TSS] was treated by mixed filamentous fungi Penicillium corylophilum and Aspergillus niger, isolated, screened and mixed cultured in terms of their higher biodegradation potential to wastewater sludge. The biosolids was increased to about 10% w/w. Conversely, the soluble [i.e. Total dissolve solid (TDS] and insoluble substances (TSS in treated supernatant were decreased effectively in the LSB process. In the developed LSB process, 93.8 g kg-1of biosolids were enriched with fungal biomass protein and nutrients (NPK, and 98.8% of TSS, 98.2% of TDS, 97.3% of turbidity, 80.2% of soluble protein, 98.8% of reducing sugar and 92.7% of chemical oxygen demand (COD in treated sludge supernatant were removed after 8 days of treatment. Specific resistance to filtration (1.39x1012 m/kg was decreased tremendously by the microbial treatment of DWTP sludge after 6 days of fermentation. The treated biosolids in DWTP sludge was considered as pretreated resource materials for composting and converted into compost by SSB process. The SSB process was evaluated for composting by monitoring the microbial growth and its subsequent roles in biodegradation in composting bin (CB. The process was conducted using two mixed fungal cultures, Trichoderma harzianum with Phanerochaete chrysosporium 2094 and (T/P and T. harzianum and Mucor hiemalis (T/M; and two bulking materials, sawdust (SD and rice straw (RS. The most encouraging results of microbial growth and subsequent solid state bioconversion were exhibited in the RS than the SD. Significant decrease of the C/N ratio and germination index (GI were attained as well as the higher value of glucosamine was exhibited in compost; which

  5. Monitoring of changes in substrate characteristics during mushroom compost production.

    Science.gov (United States)

    Lyons, Gary A; Sharma, H S Shekhar; Kilpatrick, Mairead; Cheung, Linda; Moore, Solveig

    2006-06-28

    Substrates from three mushroom compost facilities in Northern Ireland, employing similar production technologies, were examined to assess the quality of the compost produced. Biochemical investigation highlighted changes in substrates through each step of the production cycle. Thermogravimetric analysis (TGA) provided useful information on fiber fraction content and extent of substrate breakdown. A comparison of productivity, chemical, and thermal data permitted assessment of the degree of bioconversion that had occurred in the decomposition from raw materials to finished substrate for each composter. One of the composters consistently produced substrate of inferior quality compared to the other two, indicating production inefficiencies during composting. Results demonstrated that allied to chemical analyses, TGA is a useful tool, providing valuable information on substrate quality and, in particular, for studying the bioconversion of lignocellulosic materials in mushroom compost.

  6. Application of NAD-dependent polyol dehydrogenases for enzymatic mannitol/sorbitol production with coenzyme regeneration.

    Science.gov (United States)

    Parmentier, S; Arnaut, F; Soetaert, W; Vandamme, E J

    2003-01-01

    D-Mannitol and D-sorbitol were produced enzymatically from D-fructose using NAD-dependent polyol dehydrogenases. For the production of D-mannitol the Leuconostoc mesenteroides mannitol dehydrogenase could be used. Gluconobacter oxydans cell extract contained however both mannitol and sorbitol dehydrogenase. When this cell extract was used, the reduction of D-fructose resulted in a mixture of D-sorbitol and D-mannitol. To determine the optimal bioconversion conditions the polyol dehydrogenases were characterized towards pH- and temperature-optimum and -stability. As a compromise between enzyme activity and stability, the bioconversion reactions were performed at pH 6.5 and 25 degrees C. Since the polyol dehydrogenases are NADH-dependent, an efficient coenzyme regeneration was needed. Regeneration of NADH was accomplished by formate dehydrogenase-mediated oxidation of formate into CO2.

  7. Thermochemical pretreatments for enhancing succinic acid production from industrial hemp (Cannabis sativa L.)

    DEFF Research Database (Denmark)

    Gunnarsson, Ingólfur Bragi; Kuglarz, Mariusz; Karakashev, Dimitar Borisov

    2015-01-01

    The aim of this study was to develop an efficient thermochemical method for treatment of industrial hemp biomass, in order to increase its bioconversion to succinic acid. Industrial hemp was subjected to various thermochemical pretreatments using 0-3% H2SO4, NaOH or H2O2 at 121-180°C prior...... to enzymatic hydrolysis. The influence of the different pretreatments on hydrolysis and succinic acid production by Actinobacillus succinogenes 130Z was investigated in batch mode, using anaerobic bottles and bioreactors. Enzymatic hydrolysis and fermentation of hemp material pretreated with 3% H2O2 resulted...... in the highest overall sugar yield (73.5%), maximum succinic acid titer (21.9gL-1), as well as the highest succinic acid yield (83%). Results obtained clearly demonstrated the impact of different pretreatments on the bioconversion efficiency of industrial hemp into succinic acid....

  8. Miniaturization in Biocatalysis

    Directory of Open Access Journals (Sweden)

    Pedro Fernandes

    2010-03-01

    Full Text Available The use of biocatalysts for the production of both consumer goods and building blocks for chemical synthesis is consistently gaining relevance. A significant contribution for recent advances towards further implementation of enzymes and whole cells is related to the developments in miniature reactor technology and insights into flow behavior. Due to the high level of parallelization and reduced requirements of chemicals, intensive screening of biocatalysts and process variables has become more feasible and reproducibility of the bioconversion processes has been substantially improved. The present work aims to provide an overview of the applications of miniaturized reactors in bioconversion processes, considering multi-well plates and microfluidic devices, update information on the engineering characterization of the hardware used, and present perspective developments in this area of research.

  9. Optimization of Arundo donax Saccharification by (Hemicellulolytic Enzymes from Pleurotus ostreatus

    Directory of Open Access Journals (Sweden)

    Rossana Liguori

    2015-01-01

    Full Text Available An enzymatic mixture of cellulases and xylanases was produced by Pleurotus ostreatus using microcrystalline cellulose as inducer, partially characterized and tested in the statistical analysis of Arundo donax bioconversion. The Plackett-Burman screening design was applied to identify the most significant parameters for the enzymatic hydrolysis of pretreated A. donax. As the most significant influence during the enzymatic hydrolysis of A. donax was exercised by the temperature (°C, pH, and time, the combined effect of these factors in the bioconversion by P. ostreatus cellulase and xylanase was analyzed by a 33 factorial experimental design. It is worth noting that the best result of 480.10 mg of sugars/gds, obtained at 45°C, pH 3.5, and 96 hours of incubation, was significant also when compared with the results previously reached by process optimization with commercial enzymes.

  10. Optimization of Arundo donax Saccharification by (Hemi)cellulolytic Enzymes from Pleurotus ostreatus

    Science.gov (United States)

    Liguori, Rossana; Ionata, Elena; Marcolongo, Loredana; Vandenberghe, Luciana Porto de Souza; La Cara, Francesco; Faraco, Vincenza

    2015-01-01

    An enzymatic mixture of cellulases and xylanases was produced by Pleurotus ostreatus using microcrystalline cellulose as inducer, partially characterized and tested in the statistical analysis of Arundo donax bioconversion. The Plackett-Burman screening design was applied to identify the most significant parameters for the enzymatic hydrolysis of pretreated A. donax. As the most significant influence during the enzymatic hydrolysis of A. donax was exercised by the temperature (°C), pH, and time, the combined effect of these factors in the bioconversion by P. ostreatus cellulase and xylanase was analyzed by a 33 factorial experimental design. It is worth noting that the best result of 480.10 mg of sugars/gds, obtained at 45°C, pH 3.5, and 96 hours of incubation, was significant also when compared with the results previously reached by process optimization with commercial enzymes. PMID:26634214

  11. Optimization of Arundo donax Saccharification by (Hemi)cellulolytic Enzymes from Pleurotus ostreatus.

    Science.gov (United States)

    Liguori, Rossana; Ionata, Elena; Marcolongo, Loredana; Vandenberghe, Luciana Porto de Souza; La Cara, Francesco; Faraco, Vincenza

    2015-01-01

    An enzymatic mixture of cellulases and xylanases was produced by Pleurotus ostreatus using microcrystalline cellulose as inducer, partially characterized and tested in the statistical analysis of Arundo donax bioconversion. The Plackett-Burman screening design was applied to identify the most significant parameters for the enzymatic hydrolysis of pretreated A. donax. As the most significant influence during the enzymatic hydrolysis of A. donax was exercised by the temperature (°C), pH, and time, the combined effect of these factors in the bioconversion by P. ostreatus cellulase and xylanase was analyzed by a 3(3) factorial experimental design. It is worth noting that the best result of 480.10 mg of sugars/gds, obtained at 45 °C, pH 3.5, and 96 hours of incubation, was significant also when compared with the results previously reached by process optimization with commercial enzymes.

  12. Efficient lactobionic acid production from whey by Pseudomonas taetrolens under pH-shift conditions.

    Science.gov (United States)

    Alonso, Saúl; Rendueles, Manuel; Díaz, Mario

    2011-10-01

    Lactobionic acid finds applications in the fields of pharmaceuticals, cosmetics and medicine. The production of lactobionic acid from whey by Pseudomonas taetrolens was studied in shake-flasks and in a bioreactor. Shake-flask experiments showed that lactobionic acid was a non-growth associated product. A two-stage pH-shift bioconversion strategy with a pH-uncontrolled above 6.5 during the growth phase and maintained at 6.5 during cumulative production was adopted in bioreactor batch cultures. An inoculation level of 30% promoted high cell culture densities that triggered lactobionic acid production at a rate of 1.12 g/Lh. This methodology displayed efficient bioconversion with cheese whey as an inexpensive substrate for lactobionic acid production.

  13. Thermochemical pretreatments for enhancing succinic acid production from industrial hemp (Cannabis sativa L.).

    Science.gov (United States)

    Gunnarsson, Ingólfur B; Kuglarz, Mariusz; Karakashev, Dimitar; Angelidaki, Irini

    2015-04-01

    The aim of this study was to develop an efficient thermochemical method for treatment of industrial hemp biomass, in order to increase its bioconversion to succinic acid. Industrial hemp was subjected to various thermochemical pretreatments using 0-3% H2SO4, NaOH or H2O2 at 121-180°C prior to enzymatic hydrolysis. The influence of the different pretreatments on hydrolysis and succinic acid production by Actinobacillus succinogenes 130Z was investigated in batch mode, using anaerobic bottles and bioreactors. Enzymatic hydrolysis and fermentation of hemp material pretreated with 3% H2O2 resulted in the highest overall sugar yield (73.5%), maximum succinic acid titer (21.9 g L(-1)), as well as the highest succinic acid yield (83%). Results obtained clearly demonstrated the impact of different pretreatments on the bioconversion efficiency of industrial hemp into succinic acid.

  14. Influence of temperature on carbon and nitrogen dynamics during in situ aeration of aged waste in simulated landfill bioreactors.

    Science.gov (United States)

    Tong, Huanhuan; Yin, Ke; Giannis, Apostolos; Ge, Liya; Wang, Jing-Yuan

    2015-09-01

    The effect of temperature on carbon and nitrogen compounds during in situ aeration of aged waste was investigated in lab-scale simulated landfill bioreactors at 35, 45 and 55 °C, respectively. The bioreactor operated at 55 °C presented the highest carbon mineralization rate in the initial stage, suggesting accelerated biodegradation rates under thermophilic conditions. The nitrogen speciation study indicated that organic nitrogen was the dominant species of total N in aerobic bioreactors due to ammonia removal. Leachate organic nitrogen was further fractionated to elucidate the fate of individual constituent. Detailed investigation revealed the higher bioconversion rates of N-humic and N-fulvic compounds compared to hydrophilic compounds in thermophilic conditions. At the end, waste material in 55 °C bioreactor was richer in highly matured humic substances (HS) verifying the high bioconversion rates.

  15. Changes in brown coal structure caused by coal-solubilizing microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Schmiers, H.; Koepsel, R.; Weber, A.; Winkelhoefer, M.; Grosse, S. [Technische Univ. Bergakademie Freiberg (Germany). Inst. fuer Energieverfahrenstechnik und Chemieingenieurwesen

    1997-12-31

    The phenomenon of coal solubilization caused by microorganisms has been explained by various mechanisms: extraction of non-covalently bonded polar components of the coal substance by biogenic agents (chelating agents, alkaline substances) and enzyme-catalyzed cleavage of covalent bonds by extracellular enzyme systems. For this it is assumed that bond cleavage occurs on the aliphatic carbon (methylene groups, aliphatic bridges or on ester groups). As the coal has usually been treated with oxidizing agents such as H{sub 2}O{sub 2} or HNO{sub 3} before bioconversion, there is a possibility that the result of bioconversion is overlaid with the effect of the chemical treatment. We therefore studied the structural changes in the organic coal substance during pre-oxidation with H{sub 2}O{sub 2}, treatment with MnP and conversion using the fungal strains of Trichoderma and Fusarium oxysporum. (orig.)

  16. Production of high hydroxytyrosol yields via tyrosol conversion by Pseudomonas aeruginosa immobilized resting cells.

    Science.gov (United States)

    Bouallagui, Zouhaier; Sayadi, Sami

    2006-12-27

    An immobilized whole cell system was successfully performed to produce the most powerful antioxidant, hydroxytyrosol. Bioconversion of tyrosol into hydroxytyrosol was achieved via the immobilization of Pseudomonas aeruginosa resting cells in calcium alginate beads. Immobilization was advantageous as it allows immobilized cells to tolerate a greater tyrosol concentration than free cells. The bioconversion yield reached 86% in the presence of 5 g L-1 of tyrosol when cells immobilized in alginate beads were carried out in single batches. Evaluation of kinetic parameters showed the maintenance of the same catalytic efficiency expressed as Kcat/Km for both free and immobilized cells. The use of immobilized cells in repeated batches demonstrated a notable activity stabilization since the biocatalyst reusability was extended for at least four batches with a molar yield greater than 85%.

  17. Statistical Optimization of Fermentation Conditions for Cellulase Production from Palm Oil Mill Effluent

    OpenAIRE

    Jamal I. Daoud; Md. Z. Alam

    2010-01-01

    Problem statement: Palm oil mill effluent discharged by the oil palm industries is considered as the mixed of high polluted effluent which is abundant (about 20 million tonnes year-1) and its effect contributes to the serious environmental problems through the pollution of water bodies. Approach: The aim of this study was to identify the potential of low cost substrate such as Palm Oil Mill Effluent (POME) for the production of cellulase enzyme by liquid state bioconversion. The filamentous f...

  18. Effects of Chirality on the Antifungal Potency of Methylated Succinimides Obtained by Aspergillus fumigatus Biotransformations. Comparison with Racemic Ones

    OpenAIRE

    Susana Zacchino; Agustina Postigo; Maximiliano Sortino

    2013-01-01

    Eighteen (3R) and (3R,4R)-N-phenyl-, N-phenylalkyl and N-arylsuccinimides were prepared with high enantioselectivity by biotransformation of maleimides with A. fumigatus. This environmentally friendly, clean and economical procedure was performed by the whole-cell fungal bioconversion methodology. Their corresponding eighteen racemic succinimides were prepared instead by synthetic methods. Both, the racemic and the chiral succinimides were tested simultaneously by the microbroth dilution meth...

  19. Production de terpènes fonctionnalisés par les cytochromes P450 de plantes recombinants

    OpenAIRE

    Gavira, Carole

    2013-01-01

    Our aim was to identify cytochromes P450 catalyzing hydroxylation of mono-and sesquiterpenes to produce functionalized "natural" compounds with interesting organoleptic properties for the flavor and fragrance industry. We identified 7 P450-substrate pairs showing . 45 % in vitro conversion and/or forming an expected product. The amounts of products resulting from yeast bioconversion were however too low for implementation of an industrial process. Factors limiting the nootkatone production fr...

  20. Production d'arômes de type lactone par des levures

    OpenAIRE

    Alchihab, M.; Destain, J.; Aguedo, M.; Thonart, P.

    2010-01-01

    Production of aroma lactones by yeasts. Lactones are widely distributed in foods and beverages as aroma compounds. Their extraction from natural products is very expensive. Most of them can also be obtained in a chemical way, which is not well perceived by consumers. As an alternative, biotechnology proposes to use whole cells or enzymes to produce lactones by biotransformation or bioconversion of fatty acids. Different studies and patents have been conducted on that matter. In most cases, ye...

  1. 人参毛状根生物合成熊果苷的分离与鉴定%Isolation and identification of arbutin biosynthesis by hairy roots of Panax ginseng C.A.Mey

    Institute of Scientific and Technical Information of China (English)

    栗建明; 赵明强; 丁家宜

    2004-01-01

    Using ginseng (Panax ginseng C. A. Mey.) hairy roots as a bioreactor, exogenous hydroquinone (HQ) was added aseptically to suspension of hairy roots on 22 d. Twenty-four hours after the addition of HQ, the hairy roots were separated from the medium. Through identification of TLC and HPLC, it was proved that hydroquinone has been bioconversed into arbutin, and arbutin from hairy root of P. ginseng was isolated and identified.

  2. Enzymatic Biosynthesis of Novel Resveratrol Glucoside and Glycoside Derivatives

    OpenAIRE

    Pandey, Ramesh Prasad; Parajuli, Prakash; Shin, Ju Yong; Lee, Jisun; Lee, Seul; Hong, Young-Soo; Park, Yong Il; Kim, Joong Su; Sohng, Jae Kyung

    2014-01-01

    A UDP glucosyltransferase from Bacillus licheniformis was overexpressed, purified, and incubated with nucleotide diphosphate (NDP) d- and l-sugars to produce glucose, galactose, 2-deoxyglucose, viosamine, rhamnose, and fucose sugar-conjugated resveratrol glycosides. Significantly higher (90%) bioconversion of resveratrol was achieved with α-d-glucose as the sugar donor to produce four different glucosides of resveratrol: resveratrol 3-O-β-d-glucoside, resveratrol 4′-O-β-d-glucoside, resveratr...

  3. Alkane biohydroxylation: Interests, constraints and future developments.

    Science.gov (United States)

    Soussan, Laurence; Pen, Nakry; Belleville, Marie-Pierre; Marcano, José Sanchez; Paolucci-Jeanjean, Delphine

    2016-03-20

    Alkanes constitute one of the vastest reserves of raw materials for the production of fine chemicals. This paper focuses on recent advances in alkane biohydroxylation, i.e. the bioactivation of alkanes into their corresponding alcohols. Enzyme and whole-cell biocatalysts have been reviewed. Process considerations to implement such biocatalysts in bioreactors at large scale by coupling the bioconversion with cofactor regeneration and product removal are also discussed.

  4. Projeto e construção de um bioreator para síntese orgânica assimétrica catalisada por saccharomyces cerevisiae (fermento biológico de padaria Project and construction of a bioreactor for reactions catalyzed by baker's yeast (saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Ricardo de Souza Pereira

    1997-10-01

    Full Text Available A model for the construction of a simple and cheap apparatus to be used as bioreactor for reactions catalyzed by baker's yeast (Saccharomyces cerevisiae is described. The bioconversion and separation of cells from products and residual substrates are obtained at the same time. The reactions carried out in this type of reactor are faster than those catalyzed by immobilized cells. Yeast cells can be cultivated in this bioreactor operating with cell recycling at appropriated conditions using glucose and other nutrients.

  5. The correlation between the enzymatic saccharification and the multidimensional structure of cellulose changed by different pretreatments

    OpenAIRE

    Cui, Ting; Li, Jihong; Yan, Zhipei; Yu, Menghui; Li, Shizhong

    2014-01-01

    Background The bioconversion of cellulose into simple sugars or chemicals has attracted extensive attention in recent decades. The crystal allomorphs of cellulose are key factor affecting cellulose saccharification. However, due to the influence of lignin, hemicelluloses, and different characterization methods in the literature, the effect of cellulose allomorphs on cellulose saccharification is still unresolved. Thus, a systematic research on the effect of different cellulose allomorphs on e...

  6. Process Design and Economics for the Conversion of Lignocellulosic Biomass to Hydrocarbons: Dilute-Acid and Enzymatic Deconstruction of Biomass to Sugars and Biological Conversion of Sugars to Hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Davis, R.; Tao, L.; Tan, E. C. D.; Biddy, M. J.; Beckham, G. T.; Scarlata, C.; Jacobson, J.; Cafferty, K.; Ross, J.; Lukas, J.; Knorr, D.; Schoen, P.

    2013-10-01

    This report describes one potential conversion process to hydrocarbon products by way of biological conversion of lingnocellulosic-dervied sugars. The process design converts biomass to a hydrocarbon intermediate, a free fatty acid, using dilute-acid pretreatement, enzymatic saccharification, and bioconversion. Ancillary areas--feed handling, hydrolysate conditioning, product recovery and upgrading (hydrotreating) to a final blendstock material, wastewater treatment, lignin combusion, and utilities--are also included in the design.

  7. Evaluation of Diclofenac Prodrugs for Enhancing Transdermal Delivery

    OpenAIRE

    Lobo, Shabbir; Li, Henan; Farhan, Nashid; Yan, Guang

    2013-01-01

    The purpose of this study was to evaluate the approach of using diclofenac acid (DA) prodrugs for enhancing transdermal delivery. Methanol diclofenac ester (MD), ethylene glycol diclofenac ester (ED), glycerol diclofenac ester (GD), and 1,3-propylene glycol diclofenac ester (PD) were synthesized and evaluated for their physicochemical properties such as solubilities, octanol/water partition coefficients, stratum corneum/water partition coefficients, hydrolysis rates, and bioconversion rates. ...

  8. Feasibility Studies on Static Pile Co Composting of Organic Fraction of Municipal Solid Waste With Dairy Waste Water

    OpenAIRE

    Manjula Gopinathan; Meenambal Thirumurthy

    2012-01-01

    Milk processing consumes a large amount of water and generates 6–10 liters of effluent per liter of milk processed. An effluent volume is approximately four times the volume of processed milk. Since the pollutants generated by industry are great losses of production, improvements in production efficiency are recommended to reduce pollutant loads. In this research a series of experimental studies were conducted with regard to bioconversion of organic fraction of municipal solid waste along wit...

  9. A framework for techno-economic & environmental sustainability analysis by risk assessment for conceptual process evaluation

    DEFF Research Database (Denmark)

    Loureiro da Costa Lira Gargalo, Carina; Carvalho, Ana; Gernaey, Krist

    2016-01-01

    The need to achieve a sustainable process performance has become increasingly important in order to keep a competitive advantage in the global markets. Development of comprehensive and systematic methods to accomplish this goal is the subject of this work. To this end, a multi-level framework for...... is highlighted by screening two conceptual glycerol bioconversion routes to value-added chemicals namely 1,3-propanediol (1,3-PDO) and succinic acid....

  10. Fed-batch production of gluconic acid by terpene-treated Aspergillus niger spores.

    Science.gov (United States)

    Ramachandran, Sumitra; Fontanille, Pierre; Pandey, Ashok; Larroche, Christian

    2008-12-01

    Aspergillus niger spores were used as catalyst in the bioconversion of glucose to gluconic acid. Spores produced by solid-state fermentation were treated with 15 different terpenes including monoterpenes and monoterpenoids to permeabilize and inhibit spore germination. It was found that spore membrane permeability is significantly increased by treatment with terpenoids when compared to monoterpenes. Best results were obtained with citral and isonovalal. Studies were carried out to optimize spores concentration (10(7)-10(10) spores/mL), terpene concentrations in the bioconversion medium and time of exposure (1-18 h) needed for permeabilization of spores. Fed-batch production of gluconate was done in a bioreactor with the best conditions [10(9) spores/mL of freeze-thawed spores treated with citral (3% v/v) for 5 h] followed by sequential additions of glucose powder and pH-regulated with a solution containing 2 mol/L of either NaOH or KOH. Bioconversion performance of the spore enzyme was compared with the commercial glucose oxidase at 50, 60, and 70 degrees C. Results showed that the spore enzyme was comparatively stable at 60 degrees C. It was also found that the spores could be reutilized for more than 14 cycles with almost similar reaction rate. Similar biocatalytic activity was rendered by spores even after its storage of 1 year at -20 degrees C. This study provided an experimental evidence of the significant catalytic role played by A. niger spore in bioconversion of glucose to gluconic acid with high yield and stability, giving protection to glucose oxidase.

  11. European Science Notes. Volume 41, Number 7.

    Science.gov (United States)

    1987-07-01

    production of many nigh-value products kanes and simple cyclic terpenes , the such as pharmaceuticals and agricultural use of the microorganisms concerned... terpene esters terize the enzyme responsible for this " Microbial dehalogenases, their genet- bioconversion with a view to improving ics and biochemistry...positives. Sera from all individuals genes. Marcker and his group have so far were absorbed on HSV-infected varicella isolated six separate Lb genes from soy

  12. Production of raw starch-degrading enzyme by Aspergillus sp. and its use in conversion of inedible wild cassava flour to bioethanol.

    Science.gov (United States)

    Moshi, Anselm P; Hosea, Ken M M; Elisante, Emrode; Mamo, Gashaw; Önnby, Linda; Nges, Ivo Achu

    2016-04-01

    The major bottlenecks in achieving competitive bioethanol fuel are the high cost of feedstock, energy and enzymes employed in pretreatment prior to fermentation. Lignocellulosic biomass has been proposed as an alternative feedstock, but because of its complexity, economic viability is yet to be realized. Therefore, research around non-conventional feedstocks and deployment of bioconversion approaches that downsize the cost of energy and enzymes is justified. In this study, a non-conventional feedstock, inedible wild cassava was used for bioethanol production. Bioconversion of raw starch from the wild cassava to bioethanol at low temperature was investigated using both a co-culture of Aspergillus sp. and Saccharomyces cerevisiae, and a monoculture of the later with enzyme preparation from the former. A newly isolated strain of Aspergillus sp. MZA-3 produced raw starch-degrading enzyme which displayed highest activity of 3.3 U/mL towards raw starch from wild cassava at 50°C, pH 5.5. A co-culture of MZA-3 and S. cerevisiae; and a monoculture of S. cerevisiae and MZA-3 enzyme (both supplemented with glucoamylase) resulted into bioethanol yield (percentage of the theoretical yield) of 91 and 95 at efficiency (percentage) of 84 and 96, respectively. Direct bioconversion of raw starch to bioethanol was achieved at 30°C through the co-culture approach. This could be attractive since it may significantly downsize energy expenses.

  13. Biological conversion of aripiprazole lauroxil − An N-acyloxymethyl aripiprazole prodrug

    Directory of Open Access Journals (Sweden)

    Morten Rohde

    2014-01-01

    Full Text Available N-acyloxyalkylation of NH-acidic compounds can be a prodrug approach for e.g. tertiary or some N-heterocyclic amines and secondary amides and have the potential to modify the properties of the parent drug for specific uses, for example its physicochemical, pharmacokinetic or biopharmaceutical properties. Aripiprazole lauroxil was prepared as a model compound for such prodrugs and its bioconversion was investigated both in vitro and in vivo. Theoretically, N-acyloxyalkyl derivates of NH-acid compounds undergo a two-step bioconversion into the parent NH-acidic drug through an N-hydroxyalkyl intermediate. However, to our knowledge no published studies have investigated the formation of an intermediate in vivo. In the present study, it was demonstrated that the assumed N-hydroxymethyl intermediate was readily observed both in vitro and in vivo. In vivo, the observed plasma concentration of the intermediate was at the same level as the drug (aripiprazole. When prodrug intermediates are formed, it is important to make a proper pharmacological, pharmacokinetic and toxicological evaluation of the intermediates to ensure patient safety; however, several challenges were identified when testing an N-acyloxyalkyl prodrug. These included the development of a suitable bioanalytical method, the accurate prediction of prodrug bioconversion and thereby the related pharmacokinetics in humans and the toxicological potential of the intermediate.

  14. In-Situ Microbial Conversion of Sequestered Greenhouse Gases

    Energy Technology Data Exchange (ETDEWEB)

    Scott, A R; Mukhopadhyay, M; Balin, D F

    2012-09-06

    The objectives of the project are to use microbiological in situ bioconversion technology to convert sequestered or naturally-occurring greenhouse gases, including carbon dioxide and carbon monoxide, into methane and other useful organic compounds. The key factors affecting coal bioconversion identified in this research include (1) coal properties, (2) thermal maturation and coalification process, (3) microbial population dynamics, (4) hydrodynamics (5) reservoir conditions, and (6) the methodology of getting the nutrients into the coal seams. While nearly all cultures produced methane, we were unable to confirm sustained methane production from the enrichments. We believe that the methane generation may have been derived from readily metabolized organic matter in the coal samples and/or biosoluble organic material in the coal formation water. This raises the intriguing possibility that pretreatment of the coal in the subsurface to bioactivate the coal prior to the injection of microbes and nutrients might be possible. We determined that it would be more cost effective to inject nutrients into coal seams to stimulate indigenous microbes in the coal seams, than to grow microbes in fermentation vats and transport them to the well site. If the coal bioconversion process can be developed on a larger scale, then the cost to generate methane could be less than $1 per Mcf

  15. Utilisation potential of products of microbial coal liquefaction. Final report; Verwertungspotential der Produkte der mikrobiellen Kohleverfluessigung. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Koepsel, R.; Schmiers, H.; Grosse, S.; Weber, A.

    2002-07-01

    Ever since the discovery in the 1980s that microorganisms are capable of converting coal into soluble products research groups all over the world have been exploring the bioconversion of coal. It was at an advance stage of the present integrated project, which initially only involved microbiology research groups, that the need for a chemical working group with knowledge and experience in the area of coal chemistry and structural analysis of coal was recognised. The task of the chemical working group was to provide knowledge on the chemical nature of bioconversion products and the chemical processes of coal bioconversion. This involved identifying structural changes occurring in the feed coal as well as in its constituent humic acids and macromolecular matrix as a result of the activity of coal degrading microorganisms. [German] Nachdem Anfang der achtziger Jahre entdeckt wurde, dass sich Kohlen durch Mikroorganismen in loesliche Produkte ueberfuehren lassen, agieren weltweit Forschergruppen auf dem Gebiet der Biokonversion von Kohle. In einem fortgeschrittenen Bearbeitungsstadium des Verbundprojektes, an dem zunaechst nur mikrobiologische Arbeitsgruppen beteiligt waren, wurde die Notwendigkeit erkannt, eine chemische Arbeitsgruppe mit Kenntnissen und Erfahrungen auf den Gebieten der Kohlechemie und der Strukturanalytik von Kohlen zu integrieren. Aufgabenstellung der chemischen Arbeitsgruppe war und ist es, Erkenntnisse ueber die chemische Natur der Biokonversionsprodukte und die chemischen Ablaeufe der mikrobiellen Kohlekonversion bereitstellen. Die Aufgabenstellung umfasst die Aufklaerung der strukturellen Veraenderung der Einsatzkohle sowie ihrer Komponenten Huminsaeuren und makromolekulare Matrix durch die Einwirkung kohleabbauender Mikroorganismen. (orig.)

  16. Differential patterns of dehydroabietic acid biotransformation by Nicotiana tabacum and Catharanthus roseus cells.

    Science.gov (United States)

    Häkkinen, Suvi T; Lackman, Petri; Nygrén, Heli; Oksman-Caldentey, Kirsi-Marja; Maaheimo, Hannu; Rischer, Heiko

    2012-01-20

    The aim of this study was to use whole cell catalysts as tools for modification of selected resin acids in order to obtain value-added functional derivatives. The enzymatic bioconversion capacities of two plant species were tested towards dehydroabietic acid. Dehydroabietic acid (DHA) is an abundant resin acid in conifers, representing a natural wood protectant. It is also one of the constituents found in by-products of the kraft chemical pulping industry. DHA was fed to tobacco (Nicotiana tabacum) and Madagascar periwinkle (Catharanthus roseus) plant cell and tissue cultures and bioconversion product formation was monitored using NMR analysis. Both plant species took up DHA from culture medium, and various types of typical detoxification processes occurred in both cultures. In addition, diverse responses to DHA treatment were observed, including differences in uptake kinetics, chemical modification of added substrate and changes in overall metabolism of the cells. Interestingly, Catharanthus roseus, a host species for pharmaceutically valuable terpenoid indole alkaloids, exhibited a very different bioconversion pattern for exogenously applied DHA than tobacco, which does not possess a terpenoid indole pathway. In tobacco, DHA is readily glycosylated in the carbonyl group, whereas in periwinkle it is proposed that a cytochrome P450-catalyzed enzymatic detoxification reaction takes place before the formation of glycosylated product.

  17. Preliminary investigation of naringenin hydroxylation with recombinant E. coli expressing plant flavonoid hydroxylation gene.

    Science.gov (United States)

    Amor, Ilef Limem-Ben; Salem, Nidhal; Guedon, Emmanuel; Engasser, Jean-Marc; Chekir-Ghedrira, Leila; Ghoul, Mohamed

    2010-05-01

    Flavonoid hydroxylation is one way to increase the biological activities of these molecules and the number of hydroxyl groups needed for polymerization, esterification, alkylation, glycosylation and acylation reactions. These reactions have been suggested as a promising route to enhance flavonoid solubility and stability. In our preliminary study we hydroxylated naringenin (the first flavonoid core synthesized in plants) with recombinant E. coli harboring flavanone 3 hydroxylase (F3H). We demonstrated that recombinant E. coli harboring the F3H from Petroselinum crispum, can convert naringenin to dihydrokaempferol. The whole cell hydroxylase activity was often influenced by the stability of the plasmid harboring the cloned gene and the biomass yield. When the composition of the growth media became richer the amount of formed product decreased about twofold; the naringenin bioconversion yield in LB media was 70% and decreased to 33% in TB. However, the enrichment of culture media increased the biomass yield nearly threefold in LB media, only 0.5 g/L of bacteria was formed, but in TB there was 1.6 g/L. Thus, LB constitutes the best medium for naringenin bioconversion using the recombinant E. coli harboring the F3H; this allows for maximum bioconversion yield and plasmid stability when compared with the fourth tested culture medium. Consequently, E. coli harboring F3H from Petroselinum crispum can be used to produce flavonoids hydroxylated in position 3 that can serve in additional reactions like polymerization, glycosylation, and acylation,

  18. Production of Prednisolone by Pseudomonas oleovorans Cells Incorporated Into PVP/PEO Radiation Crosslinked Hydrogels

    Directory of Open Access Journals (Sweden)

    Abeer Abd El-Hady

    2004-01-01

    Full Text Available In order to rise the yield of prednisolone from hydrocortisone, the Pseudomonas oleovorans cells were entrapped into radiation crosslinked poly (vinyl pyrrolidone/poly(ethylene oxide (PVP/PEO hydrogel of different gel contents. The factors affecting the gel content and swelling behavior of the polymeric gel, such as polymer composition, polymer blend concentration, and irradiation doses, were investigated. The formation of gels having a good strength with the ability to retain a desirable amount of water in their three-dimensional network can be achieved by using PVP/PEO copolymer of composition (90:10 and concentration of 15% prepared at 20 kGy irradiation dose. At these conditions the prepared hydrogel is considered the most favorable one that gave the highest hydrocortisone bioconversion and prednisolone yield, 81% and 62.8%, respectively. The improvement of prednisolone yield was also achieved by increasing substrate concentration. Maximum hydrocortisone bioconversion (86.44 was obtained at 18 hours by using substrate concentration of 30 mg. Reusability of immobilized Pseudomonas oleovorans entrapped into PVP/PEO copolymer hydrogel was studied. The results indicated that the transformation capacity of hydrocortisone to prednisolone highly increased by the repeated use of copolymer for 4 times. This was accompanied by an increase in prednisolone yield to 89% and the bioconversion of hydrocortisone was 98.8%.

  19. Novel Halomonas sp. B15 isolated from Larnaca Salt Lake in Cyprus that generates vanillin and vanillic acid from ferulic acid.

    Science.gov (United States)

    Vyrides, Ioannis; Agathangelou, Maria; Dimitriou, Rodothea; Souroullas, Konstantinos; Salamex, Anastasia; Ioannou, Aristostodimos; Koutinas, Michalis

    2015-08-01

    Vanillin is a high value added product with many applications in the food, fragrance and pharmaceutical industries. A natural and low-cost method to produce vanillin is by microbial bioconversions through ferulic acid. Until now, limited microorganisms have been found capable of bioconverting ferulic acid to vanillin at high yield. This study aimed to screen halotolerant strains of bacteria from Larnaca Salt Lake which generate vanillin and vanillic acid from ferulic acid. From a total of 50 halotolenant/halophilic strains 8 grew in 1 g/L ferulic acid and only 1 Halomonas sp. B15 and 3 Halomonas elognata strains were capable of bioconverting ferulic acid to vanillic acid at 100 g NaCl/L. The highest vanillic acid (365 mg/L) at these conditions generated by Halomonas sp. B15 which corresponds to ferulic acid bioconversion yield of 36.5%. Using the resting cell technique with an initial ferulic acid concentration of 0.5 g/L at low salinity, the highest production of vanillin (245 mg/L) took place after 48 h, corresponding to a bioconversion yield of 49%. This is the first reported Halomonas sp. with high yield of vanillin production from ferulic acid at low salinity.

  20. In situ detoxification of the fermentation medium during gamma-decalactone production with the yeast sporidiobolus salmonicolor

    Science.gov (United States)

    Dufosse; Souchon; Feron; Latrasse; Spinnler

    1999-01-01

    gamma-Decalactone (gamma-C10) is known to be highly toxic for the microorganims used for its production. In this work, three techniques were studied in order to overcome this toxicity during a bioconversion process using ricinoleic acid as precursor of the lactone: in situ trapping in oily phases, in porous hydrophobic sorbents and in beta-cyclodextrins. Oily phases added to the media (olive, Miglyol, tributyrin, and paraffin) had a protective effect on Sp. salmonicolor, and they improved the lactone production. beta-cyclodextrins, which have a hydrophobic cavity that can trap molecules such as gamma-C10, have been used to protect the yeasts. The results showed insufficient preservation of cell viability. Some sorbents (activated carbon and polystyrene-based sorbents) were successfully tested during bioconversion. In all cases viability exceeded the reference one. Nevertheless the aroma production was 30% lower than the reference. All of these solutions led to some enhancement of the cell viability during bioconversion of methyl ricinoleate to gamma-C10. For improvement of the lactone production, the oil trapping method seemed to be the best with the experimental conditions tested.

  1. Preliminary Economics for Hydrocarbon Fuel Production from Cellulosic Sugars

    Energy Technology Data Exchange (ETDEWEB)

    Collett, James R.; Meyer, Pimphan A.; Jones, Susanne B.

    2014-05-18

    Biorefinery process and economic models built in CHEMCAD and a preliminary, genome-scale metabolic model for the oleaginous yeast Lipomyces starkeyi were used to simulate the bioconversion of corn stover to lipids, and the upgrading of these hydrocarbon precursors to diesel and jet fuel. The metabolic model was based on the recently released genome sequence for L. starkeyi and on metabolic pathway information from the literature. The process model was based on bioconversion, lipid extraction, and lipid oil upgrading data found in literature, on new laboratory experimental data, and on yield predictions from the preliminary L. starkeyi metabolic model. The current plant gate production cost for a distillate-range hydrocarbon fuel was estimated by the process model Base Case to be $9.5/gallon ($9.0 /gallon of gasoline equivalent) with assumptions of 2011$, 10% internal return on investment, and 2205 ton/day dry feed rate. Opportunities for reducing the cost to below $5.0/gallon, such as improving bioconversion lipid yield and hydrogenation catalyst selectivity, are presented in a Target Case. The process and economic models developed for this work will be updated in 2014 with new experimental data and predictions from a refined metabolic network model for L. starkeyi. Attaining a production cost of $3.0/gallon will require finding higher value uses for lignin other than power generation, such as conversion to additional fuel or to a co-product.

  2. Grass Lignocellulose

    Science.gov (United States)

    Akin, Danny E.

    Grass lignocelluloses are limited in bioconversion by aromatic constituents, which include both lignins and phenolic acids esters. Histochemistry, ultraviolet absorption microspectrophotometry, and response to microorganisms and specific enzymes have been used to determine the significance of aromatics toward recalcitrance. Coniferyl lignin appears to be the most effective limitation to biodegradation, existing in xylem cells of vascular tissues; cell walls with syringyl lignin, for example, leaf sclerenchyma, are less recalcitrant. Esterified phenolic acids, i.e., ferulic and p-coumaric acids, often constitute a major chemical limitation in nonlignified cell walls to biodegradation in grasses, especially warm-season species. Methods to improve biodegradability through modification of aromatics include: plant breeding, use of lignin-degrading white-rot fungi, and addition of esterases. Plant breeding for new cultivars has been especially effective for nutritionally improved forages, for example, bermudagrasses. In laboratory studies, selective white-rot fungi that lack cellulases delignified the lignocellulosic materials and improved fermentation of residual carbohydrates. Phenolic acid esterases released p-coumaric and ferulic acids for potential coproducts, improved the available sugars for fermentation, and improved biodegradation. The separation and removal of the aromatic components for coproducts, while enhancing the availability of sugars for bioconversion, could improve the economics of bioconversion.

  3. Permeabilization and inhibition of the germination of spores of Aspergillus niger for gluconic acid production from glucose.

    Science.gov (United States)

    Ramachandran, Sumitra; Fontanille, Pierre; Pandey, Ashok; Larroche, Christian

    2008-07-01

    In this study, the role of citral to permeabilize the spores of Aspergillus niger and replace sodium azide in the bioconversion medium was studied. Further, characterization of glucose oxidase of spores was carried out by exposing both permeabilized and unpermeabilized spores to different pressures (1, 2, 2.7 kb) and temperatures (60, 70, 80, 90 degrees C). Unpermeabilized spores after exposure to high temperatures were permeabilized by freezing before using as catalyst in the bioconversion reaction. Results showed that citral permeabilized the spores and could inhibit spore germination in the bioconversion medium. Rate of reaction was significantly increased from 1.5 to 4.35 g/Lh which was higher than the commercial glucose oxidase 2g/Lh). Glucose oxidase activity of A. niger was resistant to pressure. However, pressure treatment could not permeabilize them. Behaviour of fresh and permeabilized spores to temperature varied significantly. Glucose oxidase activity of fresh spores exposed to high temperature was unaffected at 70 degrees C till 15 min and 84% of relative activity was retained even after 1h at 70 degrees C while permeabilized spore got inactivated at 70 degrees C for 15 min, which followed the same pattern as commercial glucose oxidase. Cellular membrane integrity was lost due to permeabilization by freezing which resulted in heat-inactivation of glucose oxidase when spores were permeabilized before heat treatment. Thus, glucose oxidase of spore remains heat stable when unpermeabilized and active while permeabilized and its reaction rate is higher than the commercial glucose oxidase.

  4. Application of Taguchi Design and Response Surface Methodology for Improving Conversion of Isoeugenol into Vanillin by Resting Cells of Psychrobacter sp. CSW4.

    Science.gov (United States)

    Ashengroph, Morahem; Nahvi, Iraj; Amini, Jahanshir

    2013-01-01

    For all industrial processes, modelling, optimisation and control are the keys to enhance productivity and ensure product quality. In the current study, the optimization of process parameters for improving the conversion of isoeugenol to vanillin by Psychrobacter sp. CSW4 was investigated by means of Taguchi approach and Box-Behnken statistical design under resting cell conditions. Taguchi design was employed for screening the significant variables in the bioconversion medium. Sequentially, Box-Behnken design experiments under Response Surface Methodology (RSM) was used for further optimization. Four factors (isoeugenol, NaCl, biomass and tween 80 initial concentrations), which have significant effects on vanillin yield, were selected from ten variables by Taguchi experimental design. With the regression coefficient analysis in the Box-Behnken design, a relationship between vanillin production and four significant variables was obtained, and the optimum levels of the four variables were as follows: initial isoeugenol concentration 6.5 g/L, initial tween 80 concentration 0.89 g/L, initial NaCl concentration 113.2 g/L and initial biomass concentration 6.27 g/L. Under these optimized conditions, the maximum predicted concentration of vanillin was 2.25 g/L. These optimized values of the factors were validated in a triplicate shaking flask study and an average of 2.19 g/L for vanillin, which corresponded to a molar yield 36.3%, after a 24 h bioconversion was obtained. The present work is the first one reporting the application of Taguchi design and Response surface methodology for optimizing bioconversion of isoeugenol into vanillin under resting cell conditions.

  5. Valorization of industrial waste and by-product streams via fermentation for the production of chemicals and biopolymers.

    Science.gov (United States)

    Koutinas, Apostolis A; Vlysidis, Anestis; Pleissner, Daniel; Kopsahelis, Nikolaos; Lopez Garcia, Isabel; Kookos, Ioannis K; Papanikolaou, Seraphim; Kwan, Tsz Him; Lin, Carol Sze Ki

    2014-04-21

    The transition from a fossil fuel-based economy to a bio-based economy necessitates the exploitation of synergies, scientific innovations and breakthroughs, and step changes in the infrastructure of chemical industry. Sustainable production of chemicals and biopolymers should be dependent entirely on renewable carbon. White biotechnology could provide the necessary tools for the evolution of microbial bioconversion into a key unit operation in future biorefineries. Waste and by-product streams from existing industrial sectors (e.g., food industry, pulp and paper industry, biodiesel and bioethanol production) could be used as renewable resources for both biorefinery development and production of nutrient-complete fermentation feedstocks. This review focuses on the potential of utilizing waste and by-product streams from current industrial activities for the production of chemicals and biopolymers via microbial bioconversion. The first part of this review presents the current status and prospects on fermentative production of important platform chemicals (i.e., selected C2-C6 metabolic products and single cell oil) and biopolymers (i.e., polyhydroxyalkanoates and bacterial cellulose). In the second part, the qualitative and quantitative characteristics of waste and by-product streams from existing industrial sectors are presented. In the third part, the techno-economic aspects of bioconversion processes are critically reviewed. Four case studies showing the potential of case-specific waste and by-product streams for the production of succinic acid and polyhydroxyalkanoates are presented. It is evident that fermentative production of chemicals and biopolymers via refining of waste and by-product streams is a highly important research area with significant prospects for industrial applications.

  6. Saccharomyces pastorianus as cell factory to improve production of fructose 1,6-diphosphate using novel fermentation strategies

    Directory of Open Access Journals (Sweden)

    Chiara Schiraldi

    2015-08-01

    Full Text Available Enzymatic phosphorylation of glucose with inorganic phosphate, mediated by permeabilized yeast cells, is one of the methods commonly used to manufacture fructose 1,6-diphosphate, a compound of pharmaceutical interest. This process requires high concentrations of yeast active biomass, that is the catalyst of bioconversion of glucose and inorganic phosphate into fructose 1,6-diphosphate. In this study we firstly describe the high cell density production of a brewer's Saccharomyces strain (Saccharomyces pastorianus DSM 6581, focusing on the optimization of medium composition and exploiting fed-batch strategies and novel technologies based on membrane bioreactors. In fed-batch fermentation an appropriate exponential feed profile was set up to maintain the glucose concentration in the bioreactor below 0.9 g·L-1, thus yielding reproducibly 58 g dry weight biomass per liter in 80 h fermentation, improving eight-fold batch processes output. In addition a higher final biomass density was reached when implementing a microfiltration strategy (70 g dry weight biomass, that led to a productivity of 2.1 gcdw·L-1·h-1, 2.4-fold the fed-batch one. Successively, this biomass was opportunely permeabilized and proved capable of catalyzing the bioconversion of glucose into fructose 1,6-diphosphate. Acting on critical parameters of the bioconversion (substrates molar ratio, catalyst concentration and permeabilization agent, fructose 1,6-diphosphate was produced, after 3 h of process, at 56.3 ± 1 g·L-1 with a yield of 80% of the theoretical value.

  7. 转化RSA为氢化可的松的新月弯胞霉筛选%SCREENING OF CURVULARIA LNATA WITH THE ABILITY OF BIOCONVERTING RSA TO HYDROCORTISONE SCREENING OF CURVULARIA LNATA WITH THE ABILITY OF BIOCONVERTING RSA TO HYDROCORTISONE

    Institute of Scientific and Technical Information of China (English)

    杜连祥; 王敏; 王赓; 孙烨

    2001-01-01

    A strain C4 with ability of bioconversion from steroid RSA to hydrocortisone was selected fron the soil sample. It was identifide as Cuvularia Iunata according its morphological characters of clump and individuals. The optimum culture medium was established by orthogonal experiments :glucose 10g ,soybean powder 10g,water 1000mL, pH6.5. Determined by silica gel chromatography and high-performance liquid chromatography, the bioconversion ratio of hydrocortisone was 34%. At the same tine, the percentage change of RSA,hydrocortisone and other byproducts were measured during the course of bioconversion.%从土样中筛选到1株能转化甾体化合物RSA(17α-羟基孕甾-4-烯-3,20-二酮-21-醋酸酯)生成氢可的松(11β,17a,2l-三羟基孕甾-4-烯-3,20-二酮)的C4菌株,经菌落形态与个体形态观察,初步鉴定为新月弯胞霉(curvularia lunata)。正交实验确定该菌株的最适培养基为:葡萄糖10g,黄豆粉10g,自来水1000mL,pH6.5.经硅胶层析和高交液相色谱测定,氢化可的松转化率为34%。同时还测定了转化过程中RSA、氢化可的松及其它副产物的百分含量的变化。

  8. Vermicomposting of Taro (Colocasia esculenta) with two epigeic earthworm species.

    Science.gov (United States)

    Kurien, J; Ramasamy, E V

    2006-07-01

    The bioconversion potential of two epigeic species (Eisenia foetida Sav. and Eudrilus eugeniae Kinberg) of earthworms was assessed in terms of efficiency and sustainability of vermicomposting of Taro (Colocasia esculenta (Linn) Schott in Schott and Endl). In different vermireactors, each run in triplicates with one of the two species of earthworms, and 60 g of 6:1 Colocasia:cowdung as feed, vermicasts were produced with steadily increasing output in all the reactors. E. eugeniae was found to be more efficient producer of vermicasts than E. foetida. In all reactors, the earthworms grew well, increasing their weights and number.

  9. Growth, nutrient uptake and carbohydrate production in laboratory cultures of Spirulina major (Cyanophyceae). Final report Jan 81-Dec 82

    Energy Technology Data Exchange (ETDEWEB)

    Rhyne, C.F.; Crump, L.A.

    1983-07-01

    The basic aim of this study was to develop and analyze a photo-synthetic bioconversion system utilizing marine algae as the basis for the production of a useable feedstock (algae food reserve) by achieving the following: Analysis of various marine algae found along the Mississippi and Alabama coasts based on growth potential in a wastewater/seawater mixture. Evaluation of procedures used in maximizing production of food reserves in the selected marine algae. Study of the wastewater treatment relative to NO3, NH4 and PO4 utilized by the algae biomass.

  10. Journal of Nire, Volume 2, No. 2, March 1993

    Energy Technology Data Exchange (ETDEWEB)

    1993-01-01

    Contents: molecular structure of coal studied by solvent extraction; researches on bioconversion of coal into liquid product; structural changes during carbonization and oxidation of coal; methanol-mediated continuous extraction of phenolic compounds from coal liquid; properties of adsorbents for collection and analysis of trace amounts of chlorofluorocarbons in air; ab initio study of vibrational frequency shift upon the 1:1 acetone-iodine complex formation; a novel spectroscopic measurement method of rf plasma for temperature and electron density diagnoses; on United States-Japan conference on development and utilization of natural resources.

  11. Metabolism of benzonitrile by Cryptococcus sp. UFMG-Y28.

    Science.gov (United States)

    Rezende, R P; Dias, J C; Ferraz, V; Linardi, V R

    2000-01-01

    The yeast Cryptococcus sp. UFMG-Y28 can utilize benzonitrile as a nitrogen and possible additional carbon source. The kinetics of growth on Yeast Carbon Base (YCB) added of benzonitrile as sole nitrogen source showed that benzonitrile was metabolized to benzoic acid and ammonia. Liquid chromatography analysis indicated that Cryptococcus sp. UFMG-Y28 metabolized 12 mM benzonitrile to 10 mM benzoic acid. Resting cells cultivated on YCB-propionitrile medium showed nitrilase activity against benzonitrile. This strain appears to be promising for bioconversion of nitriles to high value acids and for bioremediation of sites contaminated with aliphatic and aromatic nitriles.

  12. Water hyacinth a potential source for value addition: An overview.

    Science.gov (United States)

    Sindhu, Raveendran; Binod, Parameswaran; Pandey, Ashok; Madhavan, Aravind; Alphonsa, Jose Anju; Vivek, Narisetty; Gnansounou, Edgard; Castro, Eulogio; Faraco, Vincenza

    2017-04-01

    Water hyacinth a fresh water aquatic plant is considered as a noxious weed in many parts of the world since it grows very fast and depletes nutrients and oxygen from water bodies adversely affecting the growth of both plants and animals. Hence conversion of this problematic weed to value added chemicals and fuels helps in the self-sustainability especially for developing countries. The present review discusses the various value added products and fuels which can be produced from water hyacinth, the recent research and developmental activities on the bioconversion of water hyacinth for the production of fuels and value added products as well as its possibilities and challenges in commercialization.

  13. The Impact of Enzyme Characteristics on Corn Stover Fiber Degradation and Acid Production During Ensiled Storage

    Science.gov (United States)

    Ren, Haiyu; Richard, Tom L.; Moore, Kenneth J.

    Ensilage can be used to store lignocellulosic biomass before industrial bioprocessing. This study investigated the impacts of seven commerical enzyme mixtures derived from Aspergillus niger, Trichoderma reesei, and T. longibrachiatum. Treatments included three size grades of corn stover, two enzyme levels (1.67 and 5 IU/g dry matter based on hemicellulase), and various ratios of cellulase to hemicellulase (C ∶ H). The highest C ∶ H ratio tested, 2.38, derived from T. reesei, resulted in the most effective fermentation, with lactic acid as the dominant product. Enzymatic activity during storage may complement industrial pretreatment; creating synergies that could reduce total bioconversion costs.

  14. Camomile autofermentation in polyethylene glycol/dextran two-phase system

    Directory of Open Access Journals (Sweden)

    Đaković Sanja D.

    2008-01-01

    Full Text Available The objective of this study was the investigation of the extractive bioconversion of apigenin-7-O-β-glucoside in camomile ligulate flowers into apigenin by autofermentation in polyethylene glycol 6000/dextran 200000 two-phase system. In 22.5% polyethylene glycol/14% dextran aqueous two-phase system the obtained yield of apigenin in the top phase was 96.5%. In the presence of plant material that partiotioned to the interphase, the yield of apigenin in the top phase was 3.5 times higher in comparison to the model system.

  15. [Application of process engineering to remove lignocellulose fermentation inhibitors].

    Science.gov (United States)

    Wang, Lan; Xia, Menglei; Chen, Hongzhang

    2014-05-01

    Fermentation inhibitors are toxic to cells, which is one of the bottlenecks for lignocellulose bio-refinery process. How to remove those inhibitors serves a key role in the bioconversion of lignocellulose. This article reviews the sources and the types of the inhibitors, especially the updated removal strategies including physical methods, chemical methods, biological methods and inhibitor-tolerant strain construction strategies. Based on these, we introduce a new bio-refinery model named "fractional conversion", which reduces the production of inhibitors at pretreatment stage, and a novel in situ detoxification method named "fermentation promoter exploitation technology". This review could provide new research ideas on the removal of fermentation inhibitors.

  16. The acid-tolerant L-arabinose isomerase from the mesophilic Shewanella sp. ANA-3 is highly active at low temperatures

    Directory of Open Access Journals (Sweden)

    Rhimi Moez

    2011-11-01

    Full Text Available Abstract Background L-arabinose isomerases catalyse the isomerization of L-arabinose into L-ribulose at insight biological systems. At industrial scale of this enzyme is used for the bioconversion of D-galactose into D-tagatose which has many applications in pharmaceutical and agro-food industries. The isomerization reaction is thermodynamically equilibrated, and therefore the bioconversion rates is shifted towards tagatose when the temperature is increased. Moreover, to prevent secondary reactions it will be of interest to operate at low pH. The profitability of this D-tagatose production process is mainly related to the use of lactose as cheaper raw material. In many dairy products it will be interesting to produce D-tagatose during storage. This requires an efficient L-arabinose isomerase acting at low temperature and pH values. Results The gene encoding the L-arabinose isomerase from Shewanella sp. ANA-3 was cloned and overexpressed in Escherichia coli. The purified protein has a tetrameric arrangement composed by four identical 55 kDa subunits. The biochemical characterization of this enzyme showed that it was distinguishable by its maximal activity at low temperatures comprised between 15-35°C. Interestingly, this biocatalyst preserves more than 85% of its activity in a broad range of temperatures from 4.0 to 45°C. Shewanella sp. ANA-3 L-arabinose isomerase was also optimally active at pH 5.5-6.5 and maintained over 80% of its activity at large pH values from 4.0 to 8.5. Furthermore, this enzyme exhibited a weak requirement for metallic ions for its activity evaluated at 0.6 mM Mn2+. Stability studies showed that this protein is highly stable mainly at low temperature and pH values. Remarkably, T268K mutation clearly enhances the enzyme stability at low pH values. Use of this L-arabinose isomerase for D-tagatose production allows the achievement of attractive bioconversion rates of 16% at 4°C and 34% at 35°C. Conclusions Here we

  17. Influence of natural coagulants on isoflavones and antioxidant activity of tofu.

    Science.gov (United States)

    Rekha, C R; Vijayalakshmi, G

    2010-08-01

    Tofu (instead of preparing using synthetic coagulant) was prepared using coagulants of plant origin (Citrus limonum, Garcinia indica, Tamarindus indica, Phyllanthus acidus and Passiflora edulis). Total crude protein and fat contents were highest in tofu prepared using G. indica and T. indica (72.5% dbw) compared to synthetic coagulant. Tofu prepared with natural coagulants had signifi cantly higher antioxidant activity compared to synthetic coagulant. Bioconversion of isoflavone glucosides (daidzin and genistin) into their corresponding bioactive aglycones (daidzein and genistein) was observed in tofu. The difference between glucosides and aglycones contents in soy milk was significant but there was not much difference in tofu coagulated with synthetic and natural coagulants.

  18. Biotechnological strategies for glycerol utilization derived from bio diesel production; Glicerol de biodiesel: estrategias biotecnologicas para o aproveitamento do glicerol gerado da producao de biodiesel

    Energy Technology Data Exchange (ETDEWEB)

    Rivaldi, Juan Daniel; Sarrouh, Boutros Fouad; Silva, Silvio Silverio da [Universidade de Sao Paulo (USP), Lorena, SP (Brazil). Escola de Engenharia], e-mail: danielrivaldi@gmail.com; Fiorilo, Rodolfo [DAFFER Quimica Ltda., Mairipora, SP (Brazil)

    2007-07-01

    The claim for reducing environment pollution stimulates the world market of clean fuels. Bio fuels as bio diesel, represents a renewable and environmentally safety alternative to fossil fuel. Nonetheless, its production is increasing considerably, and as a consequence, the amount of raw glycerol (byproduct) generated is growing exponentially. With the aim to reduce environment problems due to accumulation of glycerol, biotechnological strategies for its bioconversion in value-added products are being implementing. This work presents detailed arguments on the metabolic mechanisms of glycerol assimilation by microorganisms, as well as, a description of the most recent biotechnological processes applied to obtain bio products from glycerol. (author)

  19. Fossil Energy Program semiannual progress report for October 1992 through March 1993

    Energy Technology Data Exchange (ETDEWEB)

    Judkins, R.R. [Oak Ridge National Lab., TN (United States)

    1993-07-01

    This report covers progress made during the period October 1, 1992, through March 31, 1993, for research and development projects that contribute to the advancement of various fossil energy technologies. Projects on the Fossil Energy Program are supported by the DOE Office of Fossil Energy, the DOE Morgantown Energy Technology Center, the DOE Pittsburgh Energy Technology Center, the DOE Fossil Energy Clean Coal Technology Program, the DOE Fossil Energy Office of Petroleum Reserves, and the US Agency for International Development. In particular, projects related to materials and coal combustion, environmental analysis, and bioconversion are described.

  20. Microbiology and physiology of anaerobic fermentation of cellulose. Annual report for 1990, 1992, 1993 and final report

    Energy Technology Data Exchange (ETDEWEB)

    Ljungdahl, L.G.; Wiegel, J.; Peck, H.D. Jr.; Mortenson, L.E.

    1993-08-31

    This report focuses on the bioconversion of cellulose to methane by various anaerobes. The structure and enzymatic activity of cellulosome and polycellulosome was studied in Clostridium thermocellum. The extracellular enzymes involved in the degradation of plant material and the physiology of fermentation was investigated in anaerobic fungi. Enzymes dealing with CO, CO{sub 2}, H{sub 2}, CH{sub 3}OH, as well as electron transport and energy generation coupled to the acetyl-CoA autotrophic pathway was studied in acetogenic clostridia.

  1. Bioethanol from biomass containing lignocellulose - potential and technologies; Bioethanol aus lignocellulosehaltiger Biomasse - Potenziale und Technologien

    Energy Technology Data Exchange (ETDEWEB)

    Faulstich, M.; Schieder, D.; Wagner, U.; Staudenbauer, W.; Igelspacher, R.; Schwarz, W.H.; Meyer-Pittroff, R.; Antoni, D. [Technische Univ. Muenchen (Germany); Prechtl, S. [ATZ Entwicklungszentrum, Sulzbach-Rosenberg (Germany); Bauer, W.P.; Kroner, T. [ia GmbH, Wissensmanagement und Ingenieurleistungen, Muenchen (Germany)

    2004-07-01

    The EU biofuels directive and the tax exemption of biogenic fuels have established a new market for bioethanol in the transport sector. Low-cost lignocellulose biomass (LCB) may be an option for broadening the raw materials base for bioethanol production and to meet the increasing demand for biogenic fuels. Appropriate conversion technologies have been the subject of much research worldwide during the past few years. Against this background, the Bavarian State Minister of Agriculture and Forestry initiated a feasibility study on ethanol production by bioconversion in Bavaria. (orig.)

  2. Cascade catalysis in membranes with enzyme immobilization for multienzymatic conversion of CO2 to methanol

    DEFF Research Database (Denmark)

    Luo, Jianquan; Meyer, Anne S.; Mateiu, Ramona Valentina

    2015-01-01

    Facile co-immobilization of enzymes is highly desirable for bioconversion methods involving multienzymatic cascade reactions. Here we show for the first time that three enzymes can be immobilized in flat-sheet polymeric membranes simultaneously or separately by simple pressure-driven filtration (i...... for each single step to be optimized, not only during the enzyme immobilization but also during the reaction process, and the pressure-driven mass transfer (flow-through mode) could overcome the diffusion resistance between enzymes. This study not only offers a green and facile immobilization method...

  3. Assessment of pretreatments and enzymatic hydrolysis of wheat straw as a sugar source for bioprocess industry

    Directory of Open Access Journals (Sweden)

    Bohdan Volynets, Yaser Dahman

    2011-05-01

    Full Text Available Environmental concerns and rising oil prices have led to development of biofuels from crop residue lignocelluloses, among which wheat straw is an important feedstock used in leading commercial bioethanol processes. Lignocellulose is structured in a way that makes direct bioconversion of biomass into sugars by hydrolytic enzymes difficult and unfeasible, requiring a pretreatment step. Common biomass pretreatment technologies are assessed for potential application in obtaining fermentable sugars of wheat straw. Current outlook, challenges and opportunities on enzymatic hydrolysis of lignocellulose are also presented.

  4. Amide-transforming activity of Streptomyces: possible application to the formation of hydroxy amides and aminoalcohols.

    Science.gov (United States)

    Yamada, Shinya; Miyagawa, Taka-Aki; Yamada, Ren; Shiratori-Takano, Hatsumi; Sayo, Noboru; Saito, Takao; Takano, Hideaki; Beppu, Teruhiko; Ueda, Kenji

    2013-07-01

    To develop an efficient bioconversion process for amides, we screened our collection of Streptomyces strains, mostly obtained from soil, for effective transformers. Five strains, including the SY007 (NBRC 109343) and SY435 (NBRC 109344) of Streptomyces sp., exhibited marked conversion activities from the approximately 700 strains analyzed. These strains transformed diverse amide compounds such as N-acetyltetrahydroquinoline, N-benzoylpyrrolidine, and N-benzoylpiperidine into alcohols or N,O-acetals with high activity and regioselectivity. N,O-acetal was transformed into alcohol by serial tautomerization and reduction reactions. As such, Streptomyces spp. can potentially be used for the efficient preparation of hydroxy amides and aminoalcohols.

  5. Biotransformation of tissue-specific hormone tibolone with fungal culture Trichothecium roseum

    Science.gov (United States)

    Shah, Syed Adnan Ali; Sultan, Sadia; Zaimi bin Mohd Noor, M.

    2013-06-01

    Whole cells based biotransformation is an important tool for bioconversion of steroids. It can be used to synthesize biologically potent compounds with diverse structures. Biotransformation of tissue-specific hormone tibolone (1) with Trichothecium roseum (ATCC 13411) has being carried out for the first time. Two new and three known metabolites 2-6 were isolated from fermentation of tibolone (1) with Trichothecium roseum and their structures were characterized by 2D NMR spectroscopy and mass spectrometry. The relative stereochemistry of new metabolites 5 and 6 was deduced by 2D NOESY experiments. The effect of cultures on tibolone structural modifications and time-course studies has also been conducted.

  6. Pretreatment of wheat straw and conversion of xylose and xylan to ethanol by thermophilic anaerobic bacteria

    DEFF Research Database (Denmark)

    Ahring, Birgitte Kiær; Jensen, K.; Nielsen, P.

    1996-01-01

    Wheat straw was pretreated by wet oxidation (oxygen pressure, alkaline conditions, elevated temperature) or hydrothermal processing (without oxygen) in order to solubilize the hemicellulose, facilitating bio-conversion. The effect of oxygen pressure and sodium carbonate addition on hemicellulose...... solubilization was investigated. The two process parameters had little effect on the solubilization of hemicellulose. However alkaline conditions affected the furfural formation whereas oxygen had no effect. After pretreatment, the filtrate was used as a fermentation medium for thermophilic anaerobic bacterin...... of the microorganism to the wet oxidized filtrate was also examined. Copyright (C) 1997 Elsevier Science Ltd....

  7. Energy from the ocean. Report of the Committee on Science and Technology, U. S. House of Representatives, Ninety-Fifth Congress, Second Session by the Science Policy Research Division, Congressional Research Service, Library of Congress

    Energy Technology Data Exchange (ETDEWEB)

    1978-01-01

    In the area of renewable sources of energy from the ocean, the report includes chapters on ocean thermal energy conversion; energy from ocean waves; energy from ocean currents; energy from tides; energy from oceanic winds; energy from salinity gradients; and energy from oceanic bioconversion. Also covered are the nonrenewable sources of energy from the ocean with chapters on deep ocean oil and gas; offshore geothermal energy; and offshore hard mineral energy resources. The report concludes with a bibliography and a selection of current articles on the general subject of the energy potential of the oceans.

  8. Metabolic Engineering toward Sustainable Production of Nylon-6.

    Science.gov (United States)

    Turk, Stefan C H J; Kloosterman, Wigard P; Ninaber, Dennis K; Kolen, Karin P A M; Knutova, Julia; Suir, Erwin; Schürmann, Martin; Raemakers-Franken, Petronella C; Müller, Monika; de Wildeman, Stefaan M A; Raamsdonk, Leonie M; van der Pol, Ruud; Wu, Liang; Temudo, Margarida F; van der Hoeven, Rob A M; Akeroyd, Michiel; van der Stoel, Roland E; Noorman, Henk J; Bovenberg, Roel A L; Trefzer, Axel C

    2016-01-15

    Nylon-6 is a bulk polymer used for many applications. It consists of the non-natural building block 6-aminocaproic acid, the linear form of caprolactam. Via a retro-synthetic approach, two synthetic pathways were identified for the fermentative production of 6-aminocaproic acid. Both pathways require yet unreported novel biocatalytic steps. We demonstrated proof of these bioconversions by in vitro enzyme assays with a set of selected candidate proteins expressed in Escherichia coli. One of the biosynthetic pathways starts with 2-oxoglutarate and contains bioconversions of the ketoacid elongation pathway known from methanogenic archaea. This pathway was selected for implementation in E. coli and yielded 6-aminocaproic acid at levels up to 160 mg/L in lab-scale batch fermentations. The total amount of 6-aminocaproic acid and related intermediates generated by this pathway exceeded 2 g/L in lab-scale fed-batch fermentations, indicating its potential for further optimization toward large-scale sustainable production of nylon-6.

  9. Characterization and enzymatic hydrolysis of wood from transgenic Pinus taeda engineered with syringyl lignin or reduced lignin content

    Energy Technology Data Exchange (ETDEWEB)

    Edmunds, Charles W.; Peralta, Perry; Kelley, Stephen S.; Chiang, Vincent L.; Sharma-Shivappa, Ratna R.; Davis, Mark F.; Harman-Ware, Anne E.; Sykes, Robert W.; Gjersing, Erica; Cunningham, Michael W.; Rottmann, William; Miller, Zachary D.; Peszlen, Ilona

    2017-02-22

    Softwood is an abundant resource; however, currently its utilization for bioconversion to obtain platform sugars is limited. Pinus taeda trees which were genetically modified to either produce S lignin or to decrease lignin content were characterized with a suite of analytic techniques. Syringyl lignin was visualized in the secondary xylem of one genetic line with Maule staining. Solid-state nuclear magnetic resonance identified the S lignin units were coupled into the lignin through ..beta..-O-4 linkages, and thioacidolysis measured approximately 13% S lignin content in the same sample. Reductions of the lignin of as much as 33% were observed in the transgenics. To better understand how these modifications affect bioconversion, their amenability to hot water and dilute acid pretreatments and enzymatic hydrolysis was evaluated. Lignin reductions resulted in 1.9-3.2-fold increases in glucose release compared to the control. However, no apparent benefit was observed by S lignin incorporation at the concentrations reported in this study. These results highlight the potential for softwood cell wall properties to be improved for bioenergy/biochemical applications.

  10. The chemistry involved in the steam treatment of lignocellulosic materials

    Directory of Open Access Journals (Sweden)

    Luiz Pereira Ramos

    2003-12-01

    Full Text Available Pretreatment of lignocellulosic materials is essential for bioconversion because of the various physical and chemical barriers that greatly inhibit their susceptibility to bioprocesses such as hydrolysis and fermentation. The aim of this article is to review some of the most important pretreatment methods developed to date to enhance the conversion of lignocellulosics. Steam explosion, which precludes the treatment of biomass with high-pressure steam under optimal conditions, is presented as the pretreatment method of choice and its mode of action on lignocellulosics is discussed. The optimal pretreatment conditions for a given plant biomass are defined as those in which the best substrate for hydrolysis is obtained with the least amount of soluble sugars lost to side reactions such as dehydration. Therefore, pretreatment optimization results from a compromise between two opposite trends because hemicellulose recovery in acid hydrolysates can only be maximized at lower pretreatment severities, whereas the development of substrate accessibility requires more drastic pretreatment conditions in which sugar losses are inevitable. To account for this heterogeneity, the importance of several process-oriented parameters is discussed in detail, such as the pretreatment temperature, residence time into the steam reactor, use of an acid catalyst, susceptibility of the pretreated biomass to bioconversion, and process design.

  11. Development of the University of Washington Biofuels and Biobased Chemicals Process Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Gustafson, Richard [University of Washington

    2014-02-04

    The funding from this research grant enabled us to design and build a bioconversion steam explosion reactor and ancillary equipment such as a high pressure boiler and a fermenter to support the bioconversion process research. This equipment has been in constant use since its installation in 2012. Following are research projects that it has supported: • Investigation of novel chip production method in biofuels production • Investigation of biomass refining following steam explosion • Several studies on use of different biomass feedstocks • Investigation of biomass moisture content on pretreatment efficacy. • Development of novel instruments for biorefinery process control Having this equipment was also instrumental in the University of Washington receiving a $40 million grant from the US Department of Agriculture for biofuels development as well as several other smaller grants. The research that is being done with the equipment from this grant will facilitate the establishment of a biofuels industry in the Pacific Northwest and enable the University of Washington to launch a substantial biofuels and bio-based product research program.

  12. Acid-catalyzed steam pretreatment of lodgepole pine and subsequent enzymatic hydrolysis and fermentation to ethanol.

    Science.gov (United States)

    Ewanick, Shannon M; Bura, Renata; Saddler, John N

    2007-11-01

    Utilization of ethanol produced from biomass has the potential to offset the use of gasoline and reduce CO(2) emissions. This could reduce the effects of global warming, one of which is the current outbreak of epidemic proportions of the mountain pine beetle (MPB) in British Columbia (BC), Canada. The result of this is increasing volumes of dead lodgepole pine with increasingly limited commercial uses. Bioconversion of lodgepole pine to ethanol using SO(2)-catalyzed steam explosion was investigated. The optimum pretreatment condition for this feedstock was determined to be 200 degrees C, 5 min, and 4% SO(2) (w/w). Simultaneous saccharification and fermentation (SSF) of this material provided an overall ethanol yield of 77% of the theoretical yield from raw material based on starting glucan, mannan, and galactan, which corresponds to 244 g ethanol/kg raw material within 30 h. Three conditions representing low (L), medium (M), and high (H) severity were also applied to healthy lodgepole pine. Although the M severity conditions of 200 degrees C, 5 min, and 4% SO(2) were sufficiently robust to pretreat healthy wood, the substrate produced from beetle-killed (BK) wood provided consistently higher ethanol yields after SSF than the other substrates tested. BK lodgepole pine appears to be an excellent candidate for efficient and productive bioconversion to ethanol.

  13. Optimization of solid substrate fermentation of wheat straw.

    Science.gov (United States)

    Abdullah, A L; Tengerdy, R P; Murphy, V G

    1985-01-01

    Optimal conditions for solid substrate fermentation of wheat straw with Chaetomium cellulolyticum in laboratory-scale stationary layer fermenters were developed. The best pretreatment for wheat straw was ammonia freeze explosion, followed by steam treatment, alkali treatment, and simple autoclaving. The optimal fermentation conditions were 80% (w/w) moisture content; incubation temperature of 37 degrees C; 2% (w/w) unwashed mycelial inoculum; aeration at 0.12 L/h/g; substrate thickness of 1 to 2 cm; and duration of three days. Technical parameters for this optimized fermentation were: degree of substance utilization, 27.2%; protein yield/substrate, 0.09 g; biomass yield/bioconverted substrate, 0.40 g; degree of bioconversion of total available sugars in the substrate, 60.5%; specific efficiency of bioconversion, 70.8%; and overall efficiency of biomass production from substrate, 42.7%. Mixed culturing of Candida utilis further increased biomass production by 20%. The best mode of fermentation was a semicontinuous fed-batch fermentation where one-half of the fermented material was removed at three-day intervals and replaced by fresh substrate. In this mode, protein production was 20% higher than in batch mode, protein productivity was maintained over 12 days, and sporulation was prevented.

  14. Deletion of the Saccharomyces cerevisiae ARO8 gene, encoding an aromatic amino acid transaminase, enhances phenylethanol production from glucose.

    Science.gov (United States)

    Romagnoli, Gabriele; Knijnenburg, Theo A; Liti, Gianni; Louis, Edward J; Pronk, Jack T; Daran, Jean-Marc

    2015-01-01

    Phenylethanol has a characteristic rose-like aroma that makes it a popular ingredient in foods, beverages and cosmetics. Microbial production of phenylethanol currently relies on whole-cell bioconversion of phenylalanine with yeasts that harbour an Ehrlich pathway for phenylalanine catabolism. Complete biosynthesis of phenylethanol from a cheap carbon source, such as glucose, provides an economically attractive alternative for phenylalanine bioconversion. In this study, synthetic genetic array (SGA) screening was applied to identify genes involved in regulation of phenylethanol synthesis in Saccharomyces cerevisiae. The screen focused on transcriptional regulation of ARO10, which encodes the major decarboxylase involved in conversion of phenylpyruvate to phenylethanol. A deletion in ARO8, which encodes an aromatic amino acid transaminase, was found to underlie the transcriptional upregulation of ARO10 during growth, with ammonium sulphate as the sole nitrogen source. Physiological characterization revealed that the aro8Δ mutation led to substantial changes in the absolute and relative intracellular concentrations of amino acids. Moreover, deletion of ARO8 led to de novo production of phenylethanol during growth on a glucose synthetic medium with ammonium as the sole nitrogen source. The aro8Δ mutation also stimulated phenylethanol production when combined with other, previously documented, mutations that deregulate aromatic amino acid biosynthesis in S. cerevisiae. The resulting engineered S. cerevisiae strain produced >3 mm phenylethanol from glucose during growth on a simple synthetic medium. The strong impact of a transaminase deletion on intracellular amino acid concentrations opens new possibilities for yeast-based production of amino acid-derived products.

  15. Application of a chitosan-immobilized Talaromyces thermophilus lipase to a batch biodiesel production from waste frying oils.

    Science.gov (United States)

    Romdhane, Ines Belhaj-Ben; Romdhane, Zamen Ben; Bouzid, Maha; Gargouri, Ali; Belghith, Hafedh

    2013-12-01

    Waste frying oil, which not only harms people's health but also causes environmental pollution, can be a good alternative to partially substitute petroleum diesel through transesterification reaction. This oil contained 8.8 % of free fatty acids, which cause a problem in a base-catalyzed process. In this study, synthesis of biodiesel was efficiently catalyzed by the covalently immobilized Talaromyces thermophilus lipase and allowed bioconversion yield up to 92 % after 24 h of reaction time. The optimal molar ratio was four to six parts of methanol to one part of oil with a biocatalyst loaded of 25 wt.% of oil. Further, experiments revealed that T. thermophilus lipase, immobilized by a multipoint covalent liaison onto activated chitosan via a short spacer (glutaraldehyde), was sufficiently tolerant to methanol. In fact, using the stepwise addition of methanol, no significant difference was observed from the one-step whole addition at the start of reaction. The batch biodiesel synthesis was performed in a fixed bed reactor with a lipase loaded of 10 g. The bioconversion yield of 98 % was attained after a 5-h reaction time. The bioreactor was operated successfully for almost 150 h without any changes in the initial conversion yield. Most of the chemical and physical properties of the produced biodiesel meet the European and USA standard specifications of biodiesel fuels.

  16. Integrated waste management for rural development in Egypt.

    Science.gov (United States)

    Shehata, S M; El Shimi, S A; Elkattan, M H; Ali, B E; El-Housseini, M; El Sayad, S A; Mahmoud, M S; Zaki, A M; Hamdi, Y A; El-Nawawy, A S

    2004-01-01

    Rural areas generate a large amount of plant and animal residues that can be recycled and utilized instead of relocation and/or burning. This will lead to increasing the benefits from agricultural sector in rural communities and ensuring a better environment. To increase the economic output and environmental benefits of recycling agricultural residues, integrated system should be considered, e.g., energy--compost-recycled water system; composting--co-composting system; food-feed compost system, ensilage of crop residues. The present work was a pilot study for optimizing integrated systems for bioconversion agricultural residues completed by establishing a Training Center for Recycling Agricultural Residues (TCRAR) thereby ensuring the dissemination of the technical, environmental, and socioeconomic aspects to farmers, live stock producers, extensions service staff, and private sector. Three integrated subsystems for bioconversion of agricultural residues were developed. They were based on (i) energy--manure-recycled water system, (ii) composting and co-composting system, and (iii) food-feed/compost system.

  17. Biotechnology of intensive aerobic conversion of sewage sludge and food waste into fertilizer

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J.-Y.; Stabnikova, O.; Show, K.-Y.; Ding, H.-B.; Tay, S.T.-L.; Ivanov, V.; Tay, J.-H.

    2003-07-01

    Biotechnology for intensive aerobic bioconversion of sewage sludge and food waste into fertilizer was developed. The wastes were treated in a closed reactor under controlled aeration, stirring, pH, and temperature at 60{sup o}C, after addition of starter bacterial culture Bacillus thermoamylovorans. The biodegradation of sewage sludge was studied by decrease of volatile solids (VS), content of organic carbon and autofluorescence of coenzyme F{sub 420}. The degradation of anaerobic biomass was faster than biodegradation of total organic matter. The best fertilizer was obtained when sewage sludge was thermally pre-treated, mixed with food waste, chalk, and artificial bulking agent. The content of volatile solid and the content of organic carbon decreased at 24.8% and 13.5% of total solids, respectively, during ten days of bioconversion. The fertilizer was a powder with moisture content of 5%. It was stable, and not toxic for the germination of plant seeds. Addition of 1.0 to 1.5% of this fertilizer to the subsoil increased the growth of different plants tested by 113 to 164 %. The biotechnology can be applied in larger scale for the recycling of sewage sludge and food wastes in Singapore. (author)

  18. The modeling of ethanol production by Kluyveromyces marxianus using whey as substrate in continuous A-Stat bioreactors.

    Science.gov (United States)

    Gabardo, Sabrina; Pereira, Gabriela Feix; Rech, Rosane; Ayub, Marco Antônio Záchia

    2015-09-01

    We investigated the kinetics of whey bioconversion into ethanol by Kluyveromyces marxianus in continuous bioreactors using the "accelerostat technique" (A-stat). Cultivations using free and Ca-alginate immobilized cells were evaluated using two different acceleration rates (a). The kinetic profiles of these systems were modeled using four different unstructured models, differing in the expressions for the specific growth (μ) and substrate consumption rates (r s), taking into account substrate limitation and product inhibition. Experimental data showed that the dilution rate (D) directly affected cell physiology and metabolism. The specific growth rate followed the dilution rate (μ≈D) for the lowest acceleration rate (a = 0.0015 h(-2)), condition in which the highest ethanol yield (0.52 g g(-1)) was obtained. The highest acceleration rate (a = 0.00667 h(-2)) led to a lower ethanol yield (0.40 g g(-1)) in the system where free cells were used, whereas with immobilized cells ethanol yields increased by 23 % (0.49 g g(-1)). Among the evaluated models, Monod and Levenspiel combined with Ghose and Tyagi models were found to be more appropriate for describing the kinetics of whey bioconversion into ethanol. These results may be useful in scaling up the process for ethanol production from whey.

  19. Metabolic engineering for improved microbial pentose fermentation.

    Science.gov (United States)

    Fernandes, Sara; Murray, Patrick

    2010-01-01

    Global concern over the depletion of fossil fuel reserves, and the detrimental impact that combustion of these materials has on the environment, is focusing attention on initiatives to create sustainable approaches for the production and use of biofuels from various biomass substrates. The development of a low-cost, safe and eco-friendly process for the utilization of renewable resources to generate value-added products with biotechnological potential as well as robust microorganisms capable of efficient fermentation of all types of sugars are essential to underpin the economic production of biofuels from biomass feedstocks. Saccharomyces cerevisiae, the most established fermentation yeast used in large scale bioconversion strategies, does not however metabolise the pentose sugars, xylose and arabinose and bioengineering is required for introduction of efficient pentose metabolic pathways and pentose sugar transport proteins for bioconversion of these substrates. Our approach provided a basis for future experiments that may ultimately lead to the development of industrial S. cerevisiae strains engineered to express pentose metabolising proteins from thermophilic fungi living on decaying plant material and here we expand our original article and discuss the strategies implemented to improve pentose fermentation.

  20. Characterization of Hydrocortisone Biometabolites and 18S rRNA Gene in Chlamydomonas reinhardtii Cultures

    Directory of Open Access Journals (Sweden)

    Seyed Bagher Mosavi-Azam

    2008-10-01

    Full Text Available A unicellular microalga, Chlamydomonas reinhardtii, was isolated from rice paddy-field soil and water samples and used in the biotransformation of hydrocortisone (1. This strain has not been previously tested for steroid bioconversion. Fermentation was carried out in BG-11 medium supplemented with 0.05% substrate at 25ºC for 14 days of incubation. The products obtained were chromatographically purified and characterized using spectroscopic methods. 11b,17b-Dihydroxyandrost-4-en-3-one (2, 11b-hydroxyandrost-4-en-3,17-dione (3, 11b,17a,20b,21-tetrahydroxypregn-4-en-3-one (4 and prednisolone (5 were the main products of the bioconversion. The observed bioreaction features were the side chain degradation of the substrate to give compounds 2 and 3 and the 20-ketone reduction and 1,2-dehydrogenation affording compounds 4 and 5, respectively. A time course study showed the accumulation of product 2 from the second day of the fermentation and of compounds 3, 4 and 5 from the third day. All the metabolites reached their maximum concentration in seven days. Microalgal 18S rRNA gene was also amplified by PCR. PCR products were sequenced to confirm their authenticity as 18S rRNA gene of microalgae. The result of PCR blasted with other sequenced microalgae in NCBI showed 100% homology to the 18S small subunit rRNA of two Chlamydomonas reinhardtii spp.

  1. Enzymatic saccharification and fermentation of cellulosic date palm wastes to glucose and lactic acid

    Directory of Open Access Journals (Sweden)

    Sulaiman A. Alrumman

    2016-03-01

    Full Text Available Abstract The bioconversion of cellulosic wastes into high-value bio-products by saccharification and fermentation processes is an important step that can reduce the environmental pollution caused by agricultural wastes. In this study, enzymatic saccharification of treated and untreated date palm cellulosic wastes by the cellulases from Geobacillus stearothermophilus was optimized. The alkaline pre-treatment of the date palm wastes was found to be effective in increasing the saccharification percentage. The maximum rate of saccharification was found at a substrate concentration of 4% and enzyme concentration of 30 FPU/g of substrate. The optimum pH and temperature for the bioconversions were 5.0 and 50 °C, respectively, after 24 h of incubation, with a yield of 31.56 mg/mL of glucose at a saccharification degree of 71.03%. The saccharification was increased to 94.88% by removal of the hydrolysate after 24 h by using a two-step hydrolysis. Significant lactic acid production (27.8 mg/mL was obtained by separate saccharification and fermentation after 72 h of incubation. The results indicate that production of fermentable sugar and lactic acid is feasible and may reduce environmental pollution by using date palm wastes as a cheap substrate.

  2. Integrated Production of Xylonic Acid and Bioethanol from Acid-Catalyzed Steam-Exploded Corn Stover.

    Science.gov (United States)

    Zhu, Junjun; Rong, Yayun; Yang, Jinlong; Zhou, Xin; Xu, Yong; Zhang, Lingling; Chen, Jiahui; Yong, Qiang; Yu, Shiyuan

    2015-07-01

    High-efficiency xylose utilization is one of the restrictive factors of bioethanol industrialization. However, xylonic acid (XA) as a new bio-based platform chemical can be produced by oxidation of xylose with microbial. So, an applicable technology of XA bioconversion was integrated into the process of bioethanol production. After corn stover was pretreated with acid-catalyzed steam-explosion, solid and liquid fractions were obtained. The liquid fraction, also named as acid-catalyzed steam-exploded corn stover (ASC) prehydrolyzate (mainly containing xylose), was catalyzed with Gluconobacter oxydans NL71 to prepare XA. After 72 h of bioconversion of concentrated ASC prehydrolyzate (containing 55.0 g/L of xylose), the XA concentration reached a peak value of 54.97 g/L, the sugar utilization ratio and XA yield were 94.08 and 95.45 %, respectively. The solid fraction was hydrolyzed to produce glucose with cellulase and then fermented with Saccharomyces cerevisiae NL22 to produce ethanol. After 18 h of fermentation of concentrated enzymatic hydrolyzate (containing 86.22 g/L of glucose), the ethanol concentration reached its highest value of 41.48 g/L, the sugar utilization ratio and ethanol yield were 98.72 and 95.25 %, respectively. The mass balance showed that 1 t ethanol and 1.3 t XA were produced from 7.8 t oven dry corn stover.

  3. Methanogenic degradation of toilet-paper cellulose upon sewage treatment in an anaerobic membrane bioreactor at room temperature.

    Science.gov (United States)

    Chen, Rong; Nie, Yulun; Kato, Hiroyuki; Wu, Jiang; Utashiro, Tetsuya; Lu, Jianbo; Yue, Shangchao; Jiang, Hongyu; Zhang, Lu; Li, Yu-You

    2017-03-01

    Toilet-paper cellulose with rich but refractory carbon sources, are the main insoluble COD fractions in sewage. An anaerobic membrane bioreactor (AnMBR) was configured for sewage treatment at room temperature and its performance on methanogenic degradation of toilet paper was highlighted. The results showed, high organic removal (95%), high methane conversion (90%) and low sludge yield (0.08gVSS/gCOD) were achieved in the AnMBR. Toilet-paper cellulose was fully biodegraded without accumulation in the mixed liquor and membrane cake layer. Bioconversion efficiency of toilet paper approached 100% under a high organic loading rate (OLR) of 2.02gCOD/L/d and it could provide around 26% of total methane generation at most of OLRs. Long sludge retention time and co-digestion of insoluble/soluble COD fractions achieving mutualism of functional microorganisms, contributed to biodegradation of toilet-paper cellulose. Therefore the AnMBR successfully implemented simultaneously methanogenic bioconversion of toilet-paper cellulose and soluble COD in sewage at room temperature.

  4. Use of Vine-Trimming Wastes as Carrier for Amycolatopsis sp. to Produce Vanillin, Vanillyl Alcohol, and Vanillic Acid.

    Science.gov (United States)

    Castañón-Rodríguez, Juan Francisco; Pérez-Rodríguez, Noelia; de Souza Oliveira, Ricardo Pinheiro; Aguilar-Uscanga, María Guadalupe; Domínguez, José Manuel

    2016-10-01

    Raw vine-trimming wastes or the solid residues obtained after different fractionation treatments were evaluated for their suitability as Amycolatopsis sp. immobilization carriers during the bioconversion of ferulic acid into valuable phenolic compounds such as vanillin, vanillyl alcohol, and vanillic acid, the main flavor components of vanilla pods. Previously, physical-chemical characteristics of the materials were determined by quantitative acid hydrolysis and water absorption index (WAI), and microbiological characteristics by calculating the cell retention in the carrier (λ). Additionally, micrographics of carrier surface were obtained by field emission-scanning electron microscopy to study the influence of morphological changes during pretreatments in the adhesion of cells immobilized. The results point out that in spite of showing the lowest WAI and intermediate λ, raw material was the most appropriated substrate to conduct the bioconversion, achieving up to 262.9 mg/L phenolic compounds after 24 h, corresponding to 42.9 mg/L vanillin, 115.6 mg/L vanillyl alcohol, and 104.4 mg/L vanillic acid. The results showed the potential of this process to be applied for biotechnological production of vanillin from ferulic acid solutions; however, further studies must be carried out to increase vanillin yield. Additionally, the liquors obtained after treatment of vine-trimming wastes could be assayed to replace synthetic ferulic acid.

  5. Las lipasas: enzimas con potencial para el desarrollo de biocatalizadores inmovilizados por adsorción interfacial

    Directory of Open Access Journals (Sweden)

    Jorge González-Bacerio

    2010-06-01

    Full Text Available Las lipasas son enzimas con propiedades funcionales muy interesantes que permiten su utilización práctica en diversos campos de las industrias agroquímica, farmacéutica, de detergentes y alimentaria, así como en química fina. Entre las aplicaciones más importantes de estas moléculas se encuentran: la resolución de mezclas racémicas, la obtención de compuestos ópticamente puros y la bioconversión de principios activos. En este trabajo se presenta una amplia revisión del tema, que abarca desde aspectos estructurales y funcionales de las lipasas, hasta la inmovilización de estas enzimas mediante adsorción interfacial y su empleo en biotecnología. Palabras clave: activación interfacial, adsorción interfacial, bioconversión, esterasas. Abstract: Lipases are enzymes with very interesting functional properties that allow their practical use in different fields of Agro-Chemical, Pharmaceutical and Food industries, as well as in Fine Chemistry. Among the most relevant applications of these molecules are: racemic mixtures resolution, obtainment of optically pure compounds and bioconversion of active principles. In this work a broad review of this topic is presented. This includes since structural and functional features of lipases until the immobilization of these enzymes by interfacial adsorption and their employment in biotechnology. Key words: Bioconversion, esterases, interfacial activation, interfacial adsorption

  6. IDENTIFIKASI POTENSI ENZIM LIPASE DAN SELULASE PADA SAMPAH KULIT BUAH HASIL FERMENTASI

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    La Ode Sumarlin

    2013-12-01

    Full Text Available Fermentation is one of bioconversion to produce profitable anaerobic microbes and to produce various enzymes. Lipases and cellulases are widely used enzymes so far. Cellulases play an important role in bioconversion of organic waste cellulosic materials to glucose, single cell proteins, animal feed, and ethanol. Lipases can also degrade fatty ester bond. Therefore, both enzymes are potential to be used in industry as well as in households. Fermentation of fruit peel waste is an attempt to produce cellulase and lipase that can be carried out in a simple way. Cellulase as says was performed using DNS (3.5-dinitrosalicylic acid and acid-base titration for analysis of lipase using cooking oil as the substrate. The results showed that the highest cellulase activity was obtained from watermelon rind mixed with citrus fruit peel of 0.036 U/mL, and mixed of banana peel and citrus fruit, which was 0.035 U/mL. The optimum lipase activity was at 30 oC, pH 7, and reaction time of 60 minutes. The highest lipase activity (1.36 U/mL was obtained from mixture of watermelon and orange rind. Thus, the fruit peel waste is potential to produce cellulase and lipase by fermentation .

  7. Crude glycerol as feedstock for the sustainable production of p-hydroxybenzoate by Pseudomonas putida S12.

    Science.gov (United States)

    Verhoef, Suzanne; Gao, Nisi; Ruijssenaars, Harald J; de Winde, Johannes H

    2014-01-25

    Crude glycerol is a promising renewable feedstock in bioconversion processes for the production of fuels and chemicals. Impurities present in crude glycerol can however, negatively impact the fermentation process. Successful crude glycerol utilization requires robust microbial production hosts that tolerate and preferably, can utilize such impurities. We investigated utilization of crude, unpurified glycerol as a substrate for the production of aromatic compounds by solvent tolerant Pseudomonas putida S12. In high-cell density fed-batch fermentations, P. putida S12 surprisingly performed better on crude glycerol than on purified glycerol. By contrast, growth of Escherichia coli was severely compromised under these high cell density cultivation conditions on crude glycerol. For P. putida S12 the biomass-to-substrate yield, maximum biomass production rate and substrate uptake rate were consistently higher on crude glycerol. Moreover, production of p-hydroxybenzoate by engineered P. putida S12palB5 on crude glycerol showed a 10% yield improvement over production on purified glycerol. P. putida S12 is a favorable host for bioconversion processes utilizing crude glycerol as a substrate. Its intrinsic stress-tolerance properties provide the robustness required for efficient growth and metabolism on this renewable substrate.

  8. Vitamin A and bone health: the balancing act.

    Science.gov (United States)

    Tanumihardjo, Sherry A

    2013-01-01

    The role of vitamin A status as it relates to bone health is historical yet controversial. Population-based studies have linked high dietary intake of preformed vitamin A, which is obtained from animal-source foods, fortified foods, and some supplements, to greater risk of osteoporosis and hip fracture. In contrast, carotenoids, some of which are vitamin A precursors from plants, are associated with improved bone health. Carotenoids may be a biomarker that reflects a generally healthy lifestyle, which includes fruit and vegetable consumption. Current dietary recommendations to increase fruit and vegetable intake in the Dietary Guidelines for Americans will result in greater intakes of provitamin A carotenoids if consumers comply. This could lead to artificially high intakes of vitamin A in dietary analyses. However, multiple factors affect the bioconversion of provitamin A carotenoids to the active form of vitamin A. The human body will strive to maintain vitamin A balance by down-regulating provitamin A carotenoid bioconversion. If high preformed vitamin A intake is associated with poor bone health and provitamin A carotenoids are protective, future studies are needed to clarify the associations between total body stores of vitamin A, dietary intake of the pre- and pro-forms, and bone health throughout the life cycle.

  9. The lipoxygenase metabolic pathway in plants: potential for industrial production of natural green leaf volatiles

    Directory of Open Access Journals (Sweden)

    Gigot, C.

    2010-01-01

    Full Text Available Lipoxygenase enzymatic pathway is a widely studied mechanism in the plant kingdom. Combined actions of three enzymes: lipase, lipoxygenase (LOX and hydroperoxide lyase (HPL convert lipidic substrates such as C18:2 and C18:3 fatty acids into short chain volatiles. These reactions, triggered by cell membrane disruptions, produce compounds known as Green Leaf Volatiles (GLVs which are C6 or C9-aldehydes and alcohols. These GLVs are commonly used as flavors to confer a fresh green odor of vegetable to food products. Therefore, competitive biocatalytic productions have been developed to meet the high demand in these natural flavors. Vegetable oils, chosen for their lipidic acid profile, are converted by soybean LOX and plant HPL into natural GLVs. However this second step of the bioconversion presents low yield due to the HPL instability and the inhibition by its substrate. This paper will shortly describe the different enzymes involved in this bioconversion with regards to their chemical and enzymatic properties. Biotechnological techniques to enhance their production potentialities will be discussed along with their implication in a complete bioprocess, from the lipid substrate to the corresponding aldehydic or alcoholic flavors.

  10. A process for high-efficiency isoflavone deglycosylation using Bacillus subtilis natto NTU-18.

    Science.gov (United States)

    Kuo, Lun-Cheng; Wu, Ren-Yu; Lee, Kung-Ta

    2012-06-01

    In order to produce isoflavone aglycosides effectively, a process of isoflavone hydrolysis by Bacillus subtilis natto NTU-18 (BCRC 80390) was established. This process integrates the three stages for the production of isoflavone aglycosides in one single fermenter, including the growth of B. subtilis natto, production of β-glucosidase, deglycosylation of fed isoflavone glycosides. After 8 h of batch culture of B. subtilis natto NTU-18 in 2 L of soy medium, a total of 3 L of soy isoflavone glucoside solution containing 3.0 mg/mL of daidzin and 1.0 mg/mL of genistin was fed continuously over 34 h. The percentage deglycosylation of daidzin and genistin was 97.7% and 94.6%, respectively. The concentration of daidzein and genistein in the broth reached 1,066.8 μg/mL (4.2 mM) and 351 μg/mL (1.3 mM), respectively, and no residual daidzin or genistin was detected. The productivity of the bioconversion of daidzein and genistein over the 42 h of culture was 25.6 mg/L/h and 8.5 mg/L/h, respectively. This showed that this is an efficient bioconversion process for selective estrogen receptor modulator production.

  11. Production of chemicals from C1 gases (CO, CO2) by Clostridium carboxidivorans.

    Science.gov (United States)

    Fernández-Naveira, Ánxela; Abubackar, Haris Nalakath; Veiga, María C; Kennes, Christian

    2017-03-01

    Bioprocesses in conventional second generation biorefineries are mainly based on the fermentation of sugars obtained from lignocellulosic biomass or agro-industrial wastes. An alternative to this process consists in gasifying those same feedstocks or even other carbon-containing materials to obtain syngas which can also be fermented by some anaerobic bacteria to produce chemicals or fuels. Carbon monoxide, carbon dioxide and hydrogen, which are the main components of syngas, are also found in some industrial waste gases, among others in steel industries. Clostridium carboxidivorans is able to metabolise such gases to produce ethanol and higher alcohols, i.e. butanol and hexanol, following the Wood-Ljungdahl pathway. This does simultaneously allow the removal of volatile pollutants involved in climate change. The bioconversion is a two step process in which organic acids (acetate, butyrate, hexanoate) are produced first, followed by the accumulation of alcohols; although partial overlap in time of acids and alcohols production may sometimes take place as well. Several parameters, among others pH, temperature, or gas-feed flow rates in bioreactors, affect the bioconversion process. Besides, the accumulation of high concentrations of alcohols in the fermentation broth inhibits the growth and metabolic activity of C. carboxidivorans.

  12. Investigation of the available technologies and their feasibility for the conversion of food waste into fish feed in Hong Kong.

    Science.gov (United States)

    Cheng, Jack Y K; Lo, Irene M C

    2016-04-01

    Food waste is the largest constituent of municipal solid waste in Hong Kong, but food waste recycling is still in its infancy. With the imminent saturation of all landfill sites by 2020, multiple technologies are needed to boost up the food waste recycling rate in Hong Kong. Conversion of food waste into animal feeds is prevalent in Japan, South Korea, and Taiwan, treating over 40 % of their recycled food waste. This direction is worth exploring in Hong Kong once concerns over food safety are resolved. Fortunately, while feeding food waste to pigs and chickens poses threats to public health, feeding it to fish is considered low risk. In order to examine the feasibility of converting food waste into fish feed in Hong Kong, this paper investigates the market demand, technical viability, feed quality, regulatory hurdles, and potential contribution. The results show that a significant amount of food waste can be recycled by converting it into fish feed due to the enormous demand from feed factories in mainland China. Two conversion technologies, heat drying and black soldier fly bioconversion, are studied extensively. Black soldier fly bioconversion is preferable because the end-product, insect powder, is anticipated to gain import approval from mainland China. The authors suggest further research efforts to speed up its application for food waste recycling in urban cities.

  13. Enhanced biogas production from rice straw with various pretreatment : a review

    Directory of Open Access Journals (Sweden)

    Fahriya Puspita Sari

    2014-04-01

    Full Text Available Rice straw is one of organic material that can be used for sustainable production of bioenergy and biofuels such as biogas (about 50-75% CH4 and 25-50% CO2. Out of all bioconversion technologies for biogas production, anaerobic digestion (AD is a most cost-effective bioconversion technology that has been implemented worldwide for commercial production of electricity, heat, and compressed natural gas (CNG from organic materials. However, the utilization of rice straw for biogas production via anaerobic digestion has not been widely adopted because the complicated structure of the plant cell wall makes it resistant to microbial attack. Pretreatment of recalcitrant rice straw is essential to achieve high biogas yield in the AD process. A number of different pretreatment techniques involving using physical pretreatment (hydrothermal and freeze, chemical pretreatment (sodium carbonate – sodium sulfite, hydrogen peroxide, NMMO, alkaline, and dilute acid and biological pretreatment (fungal pretreatment also combined pretretment (microwave irradiation and chemical approaches have been investigated, but there is no report that systematically compares the performance of these pretreatment methods for application on rice straw for biogas production. This paper reviews the methods that have been studied for pretreatment of rice straw for delignification, reducing sugar, and conversion to biogas. It describes the AD process, structural and compositional properties of rice straw, and various pretreatment techniques, including the pretreatment process, parameters, performance, and advantages vs. drawbacks.

  14. The Study of the Viermicompost Influence on the Harvest and on the Quality of Forage Cultures

    Directory of Open Access Journals (Sweden)

    Larisa Cremeneac

    2011-10-01

    Full Text Available The purpose of the research was the appreciation of the viermicompost quality. This material was obtained as a result of bioconversion of organically wastes (obtained from cattle by worm cultivation, using wormculture (especially the Red Hybrid of California. The bioconversion process of organic wastes is implemented in the Experimental Section of the Scientific and Practical Institute of Biotechnologies in Animal Husbandry and Veterinary Medicine. As a result of the studies to effect in several states, including the Republic of Moldova, it has been stated that the veirmicompost has a positive influence on the productivity of cultures, diminishing the period of culture growing , increases their resistance to infavorable clamaterical conditions and to frequent phitotechnical maligns. In the agricultural production obtained as a result of cultivating on viermicompost. As a result of the research it has dean stated that the quantity of the C vitamin in some of the vegetables has increased by 1,5 – 9,4 times. What s more the viermicompost has influenced positively the quality of the alfalfa, maize and sugar fodder, in which the azoth compounds quantity has diminished by 1,32 – 2,66; 3,47 – 3,76 and 1,10 – 1,14 times, in comparison with cultures cultivars tied with the help of mineral fertilizer. So, the agricultural and ecological importance of the viermicompost consists in improving the quality of agricultural production.

  15. Reducing sugar-producing bacteria from guts of Tenebrio molitor Linnaeus (yellow mealworm) for lignocellulosic waste minimization.

    Science.gov (United States)

    Qi, Wei; Chen, Chia-Lung; Wang, Jing-Yuan

    2011-01-01

    The guts of Tenebrio Molitor Linnaeus (yellow mealworm) were used as inocula to isolate reducing sugar-producing bacteria during bioconversion of lignocellulose to reducing sugars in this study. Three carbon sources, i.e., carboxymethyl cellulose (CMC), filter paper (FP), and lignocellulosic waste (LIG), were specifically selected; and two types of culturing media (M1 and M2) were used. After 6 months of sequential cultivation, lignocellulose (i.e., polysaccharides) degradation of enrichments M1-CMC (47.5%), M1-FP (73.3%), M1-LIG (70.4%), M2-CMC (55.7%), M2-FP (73.1%) and M2-LIG (71.7%) was achieved, respectively, with incubation for 48 h. Furthermore, seven bacterial strains were successfully isolated corresponding to most of the major bands detected by denaturing gradient gel electrophoresis analysis. The maximum reducing sugars yield by the combination of Agromyces sp. C42 and Stenotrophomonas sp. A10b was 56.7 mg g·LIG(-1) of 48 h, which is approximate 2-5 times higher than the original enrichments and individual microbial strains. These findings suggest that bioconversion by microorganisms from mealworm guts has great application potential for lignocellulose hydrolysis.

  16. Biohydrogen production in a continuous stirred tank bioreactor from synthesis gas by anaerobic photosynthetic bacterium: Rhodopirillum rubrum.

    Science.gov (United States)

    Younesi, Habibollah; Najafpour, Ghasem; Ku Ismail, Ku Syahidah; Mohamed, Abdul Rahman; Kamaruddin, Azlina Harun

    2008-05-01

    Hydrogen may be considered a potential fuel for the future since it is carbon-free and oxidized to water as a combustion product. Bioconversion of synthesis gas (syngas) to hydrogen was demonstrated in continuous stirred tank bioreactor (CSTBR) utilizing acetate as a carbon source. An anaerobic photosynthetic bacterium, Rhodospirillum rubrum catalyzed water-gas shift reaction which was applied for the bioconversion of syngas to hydrogen. The continuous fermentation of syngas in the bioreactor was continuously operated at various gas flow rates and agitation speeds, for the period of two months. The gas flow rates were varied from 5 to 14 ml/min. The agitation speeds were increasingly altered in the range of 150-500 rpm. The pH and temperature of the bioreactor was set at 6.5 and 30 degrees C. The liquid flow rate was kept constant at 0.65 ml/min for the duration of 60 days. The inlet acetate concentration was fed at 4 g/l into the bioreactor. The hydrogen production rate and yield were 16+/-1.1 mmol g(-1)cell h(-1) and 87+/-2.4% at fixed agitation speed of 500 rpm and syngas flow rate of 14 ml/min, respectively. The mass transfer coefficient (KLa) at this condition was approximately 72.8h(-1). This new approach, using a biocatalyst was considered as an alternative method of conventional Fischer-Tropsch synthetic reactions, which were able to convert syngas into hydrogen.

  17. Enhanced ethanol production from brewer's spent grain by a Fusarium oxysporum consolidated system

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    Christakopoulos Paul

    2009-02-01

    Full Text Available Abstract Background Brewer's spent grain (BG, a by-product of the brewing process, is attracting increasing scientific interest as a low-cost feedstock for many biotechnological applications. BG in the present study is evaluated as a substrate for lignocellulolytic enzyme production and for the production of ethanol by the mesophilic fungus Fusarium oxysporum under submerged conditions, implementing a consolidated bioconversion process. Fermentation experiments were performed with sugar mixtures simulating the carbohydrate content of BG in order to determine the utilization pattern that could be expected during the fermentation of the cellulose and hemicellulose hydrolysate of BG. The sugar mixture fermentation study focused on the effect of the initial total sugar concentration and on the effect of the aeration rate on fermenting performance of F. oxysporum. The alkali pretreatment of BG and different aeration levels during the ethanol production stage were studied for the optimization of the ethanol production by F. oxysporum. Results Enzyme yields as high as 550, 22.5, 6.5, 3225, 0.3, 1.25 and 3 U per g of carbon source of endoglucanase, cellobiohydrolase, β-D-glucosidase, xylanase, feruloyl esterase, β-D-xylosidase and α-L-arabinofuranosidase respectively, were obtained during the growth stage under optimized submerged conditions. An ethanol yield of 109 g ethanol per kg of dry BG was obtained with alkali-pretreated BG under microaerobic conditions (0.01 vvm, corresponding to 60% of the theoretical yield based on total glucose and xylose content of BG. Conclusion The enzymatic profile of the extracellular extract from F. oxysporum submerged cultures using BG and corn cob as the carbon source was proved efficient for a successful hydrolysis of BG. The fermentation study carried out using sugar mixtures simulating BG's carbohydrates content and consecutively alkali-pretreated and untreated BG, indicates that BG hydrolysis is the bottleneck

  18. Microbial community dynamics in mesophilic anaerobic co-digestion of mixed waste.

    Science.gov (United States)

    Supaphol, Savaporn; Jenkins, Sasha N; Intomo, Pichamon; Waite, Ian S; O'Donnell, Anthony G

    2011-03-01

    This paper identifies key components of the microbial community involved in the mesophilic anaerobic co-digestion (AD) of mixed waste at Rayong Biogas Plant, Thailand. The AD process is separated into three stages: front end treatment (FET); feed holding tank and the main anaerobic digester. The study examines how the microbial community structure was affected by the different stages and found that seeding the waste at the beginning of the process (FET) resulted in community stability. Also, co-digestion of mixed waste supported different bacterial and methanogenic pathways. Typically, acetoclastic methanogenesis was the major pathway catalysed by Methanosaeta but hydrogenotrophs were also supported. Finally, the three-stage AD process means that hydrolysis and acidogenesis is initiated prior to entering the main digester which helps improve the bioconversion efficiency. This paper demonstrates that both resource availability (different waste streams) and environmental factors are key drivers of microbial community dynamics in mesophilic, anaerobic co-digestion.

  19. Steam explosion pretreatment for enhancing biogas production of late harvested hay.

    Science.gov (United States)

    Bauer, Alexander; Lizasoain, Javier; Theuretzbacher, Franz; Agger, Jane W; Rincón, María; Menardo, Simona; Saylor, Molly K; Enguídanos, Ramón; Nielsen, Paal J; Potthast, Antje; Zweckmair, Thomas; Gronauer, Andreas; Horn, Svein J

    2014-08-01

    Grasslands are often abandoned due to lack of profitability. Extensively cultivating grassland for utilization in a biogas-based biorefinery concept could mend this problem. Efficient bioconversion of this lignocellulosic biomass requires a pretreatment step. In this study the effect of different steam explosion conditions on hay digestibility have been investigated. Increasing severity in the pretreatment induced degradation of the hemicellulose, which at the same time led to the production of inhibitors and formation of pseudo-lignin. Enzymatic hydrolysis showed that the maximum glucose yields were obtained under pretreatment at 220 °C for 15 min, while higher xylose yields were obtained at 175 °C for 10 min. Pretreatment of hay by steam explosion enhanced 15.9% the methane yield in comparison to the untreated hay. Results indicate that hay can be effectively converted to methane after steam explosion pretreatment.

  20. Genomic sequence of the xylose fermenting, insect-inhabitingyeast, Pichia stipitis

    Energy Technology Data Exchange (ETDEWEB)

    Jeffries, Thomas W.; Grigoriev, Igor; Grimwood, Jane; Laplaza,Jose M.; Aerts, Andrea; Salamov, Asaf; Schmutz, Jeremy; Lindquist, Erika; Dehal, Paramvir; Shapiro, Harris; Jin, Yong-Su; Passoth, Volkmar; Richardson, Paul M.

    2007-06-25

    Xylose is a major constituent of angiosperm lignocellulose,so its fermentation is important for bioconversion to fuels andchemicals. Pichia stipitis is the best-studied native xylose fermentingyeast. Genes from P. stipitis have been used to engineer xylosemetabolism in Saccharomycescerevisiae, and the regulation of the P.stipitis genome offers insights into the mechanisms of xylose metabolismin yeasts. We have sequenced, assembled and finished the genome ofP.stipitis. As such, it is one of only a handful of completely finishedeukaryotic organisms undergoing analysis and manual curation. Thesequence has revealed aspects of genome organization, numerous genes forbiocoversion, preliminary insights into regulation of central metabolicpathways, numerous examples of co-localized genes with related functions,and evidence of how P. stipitis manages to achieve redox balance whilegrowing on xylose under microaerobic conditions.

  1. Nanofiltration, bipolar electrodialysis and reactive extraction hybrid system for separation of fumaric acid from fermentation broth.

    Science.gov (United States)

    Prochaska, Krystyna; Staszak, Katarzyna; Woźniak-Budych, Marta Joanna; Regel-Rosocka, Magdalena; Adamczak, Michalina; Wiśniewski, Maciej; Staniewski, Jacek

    2014-09-01

    A novel approach based on a hybrid system allowing nanofiltration, bipolar electrodialysis and reactive extraction, was proposed to remove fumaric acid from fermentation broth left after bioconversion of glycerol. The fumaric salts can be concentrated in the nanofiltration process to a high yield (80-95% depending on pressure), fumaric acid can be selectively separated from other fermentation components, as well as sodium fumarate can be conversed into the acid form in bipolar electrodialysis process (stack consists of bipolar and anion-exchange membranes). Reactive extraction with quaternary ammonium chloride (Aliquat 336) or alkylphosphine oxides (Cyanex 923) solutions (yield between 60% and 98%) was applied as the final step for fumaric acid recovery from aqueous streams after the membrane techniques. The hybrid system permitting nanofiltration, bipolar electrodialysis and reactive extraction was found effective for recovery of fumaric acid from the fermentation broth.

  2. Multi-scale process and supply chain modelling: from lignocellulosic feedstock to process and products.

    Science.gov (United States)

    Hosseini, Seyed Ali; Shah, Nilay

    2011-04-06

    There is a large body of literature regarding the choice and optimization of different processes for converting feedstock to bioethanol and bio-commodities; moreover, there has been some reasonable technological development in bioconversion methods over the past decade. However, the eventual cost and other important metrics relating to sustainability of biofuel production will be determined not only by the performance of the conversion process, but also by the performance of the entire supply chain from feedstock production to consumption. Moreover, in order to ensure world-class biorefinery performance, both the network and the individual components must be designed appropriately, and allocation of resources over the resulting infrastructure must effectively be performed. The goal of this work is to describe the key challenges in bioenergy supply chain modelling and then to develop a framework and methodology to show how multi-scale modelling can pave the way to answer holistic supply chain questions, such as the prospects for second generation bioenergy crops.

  3. METABOLIC MODELLING IN THE DEVELOPMENT OF CELL FACTORIES BY SYNTHETIC BIOLOGY

    Directory of Open Access Journals (Sweden)

    Paula Jouhten

    2012-10-01

    Full Text Available Cell factories are commonly microbial organisms utilized for bioconversion of renewable resources to bulk or high value chemicals. Introduction of novel production pathways in chassis strains is the core of the development of cell factories by synthetic biology. Synthetic biology aims to create novel biological functions and systems not found in nature by combining biology with engineering. The workflow of the development of novel cell factories with synthetic biology is ideally linear which will be attainable with the quantitative engineering approach, high-quality predictive models, and libraries of well-characterized parts. Different types of metabolic models, mathematical representations of metabolism and its components, enzymes and metabolites, are useful in particular phases of the synthetic biology workflow. In this minireview, the role of metabolic modelling in synthetic biology will be discussed with a review of current status of compatible methods and models for the in silico design and quantitative evaluation of a cell factory.

  4. Experimental studies and mathematical modeling of an up-flow biofilm reactor treating mustard oil rich wastewater.

    Science.gov (United States)

    Chakraborty, Chandrima; Chowdhury, Ranjana; Bhattacharya, Pinaki

    2011-05-01

    Bioremediation of lipid-rich model wastewater was investigated in a packed bed biofilm reactor (anaerobic filter). A detailed study was conducted about the influence of fatty acid concentration on biomethanation of the high-fat liquid effluent of edible oil refineries. The biochemical methane potential (BMP) of the liquid waste was reported and maximum cumulative methane production at the exit of the reactor is estimated to be 785 ml CH(4) (STP)/(gVSS added). The effects of hydraulic retention time (HRT), organic loading rate (OLR) and bed porosity on the cold gas efficiency or energy efficiency of the bioconversion process were also investigated. Results revealed that the maximum cold gas efficiency of the process is 42% when the total organic load is 2.1 g COD/l at HRT of 3.33 days. Classical substrate uninhibited Monod model is used to generate the differential system equations which can predict the reactor behavior satisfactorily.

  5. Methane recovery from animal manures: A current opportunities casebook

    Energy Technology Data Exchange (ETDEWEB)

    Lusk, P. [Resource Development Associates, Marietta, GA (United States)

    1994-12-01

    One manure management system provides not only pollution prevention but also converts a manure management problem into a new profit center. Economic evaluations and case studies of operating systems indicate that the anaerobic digestion of livestock manures is a commercially-available bioconversion technology with considerable potential for providing profitable co-products including a cost-effective renewable fuel for livestock production operations. This Casebook examines some of the current opportunities for the recovery of methane from the anaerobic digestion of animal manures. The economic evaluations are based on engineering studies of digesters that generate electricity from the recovered methane. Regression models, which can be used to estimate digester cost and internal rate of return, are developed from the evaluations. Finally, anaerobic digestion has considerable potential beyond agribusiness. Examples of digesters currently employed by other industries are provided.

  6. How to Establish a Bioregenerative Life Support System for Long-Term Crewed Missions to the Moon or Mars

    Science.gov (United States)

    Fu, Yuming; Li, Leyuan; Xie, Beizhen; Dong, Chen; Wang, Mingjuan; Jia, Boyang; Shao, Lingzhi; Dong, Yingying; Deng, Shengda; Liu, Hui; Liu, Guanghui; Liu, Bojie; Hu, Dawei; Liu, Hong

    2016-12-01

    To conduct crewed simulation experiments of bioregenerative life support systems on the ground is a critical step for human life support in deep-space exploration. An artificial closed ecosystem named Lunar Palace 1 was built through integrating efficient higher plant cultivation, animal protein production, urine nitrogen recycling, and bioconversion of solid waste. Subsequently, a 105-day, multicrew, closed integrative bioregenerative life support systems experiment in Lunar Palace 1 was carried out from February through May 2014. The results show that environmental conditions as well as the gas balance between O2 and CO2 in the system were well maintained during the 105-day experiment. A total of 21 plant species in this system kept a harmonious coexistent relationship, and 20.5% nitrogen recovery from urine, 41% solid waste degradation, and a small amount of insect in situ production were achieved. During the 105-day experiment, oxygen and water were recycled, and 55% of the food was regenerated.

  7. Microbial synthesis gas utilization and ways to resolve kinetic and mass-transfer limitations.

    Science.gov (United States)

    Yasin, Muhammad; Jeong, Yeseul; Park, Shinyoung; Jeong, Jiyeong; Lee, Eun Yeol; Lovitt, Robert W; Kim, Byung Hong; Lee, Jinwon; Chang, In Seop

    2015-02-01

    Microbial conversion of syngas to energy-dense biofuels and valuable chemicals is a potential technology for the efficient utilization of fossils (e.g., coal) and renewable resources (e.g., lignocellulosic biomass) in an environmentally friendly manner. However, gas-liquid mass transfer and kinetic limitations are still major constraints that limit the widespread adoption and successful commercialization of the technology. This review paper provides rationales for syngas bioconversion and summarizes the reaction limited conditions along with the possible strategies to overcome these challenges. Mass transfer and economic performances of various reactor configurations are compared, and an ideal case for optimum bioreactor operation is presented. Overall, the challenges with the bioprocessing steps are highlighted, and potential solutions are suggested. Future research directions are provided and a conceptual design for a membrane-based syngas biorefinery is proposed.

  8. Improved Release and Metabolism of Flavonoids by Steered Fermentation Processes: A Review

    Directory of Open Access Journals (Sweden)

    Nguyen Thai Huynh

    2014-10-01

    Full Text Available This paper provides an overview on steered fermentation processes to release phenolic compounds from plant-based matrices, as well as on their potential application to convert phenolic compounds into unique metabolites. The ability of fermentation to improve the yield and to change the profile of phenolic compounds is mainly due to the release of bound phenolic compounds, as a consequence of the degradation of the cell wall structure by microbial enzymes produced during fermentation. Moreover, the microbial metabolism of phenolic compounds results in a large array of new metabolites through different bioconversion pathways such as glycosylation, deglycosylation, ring cleavage, methylation, glucuronidation and sulfate conjugation, depending on the microbial strains and substrates used. A whole range of metabolites is produced, however metabolic pathways related to the formation and bioactivities, and often quantification of the metabolites are highly underinvestigated. This strategy could have potential to produce extracts with a high-added value from plant-based matrices.

  9. Fossil energy biotechnology: A research needs assessment. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1993-11-01

    The Office of Program Analysis of the US Department of Energy commissioned this study to evaluate and prioritize research needs in fossil energy biotechnology. The objectives were to identify research initiatives in biotechnology that offer timely and strategic options for the more efficient and effective uses of the Nation`s fossil resource base, particularly the early identification of new and novel applications of biotechnology for the use or conversion of domestic fossil fuels. Fossil energy biotechnology consists of a number of diverse and distinct technologies, all related by the common denominator -- biocatalysis. The expert panel organized 14 technical subjects into three interrelated biotechnology programs: (1) upgrading the fuel value of fossil fuels; (2) bioconversion of fossil feedstocks and refined products to added value chemicals; and, (3) the development of environmental management strategies to minimize and mitigate the release of toxic and hazardous petrochemical wastes.

  10. Overproduction of cellulase by Trichoderma reesei RUT C30 through batch-feeding of synthesized low-cost sugar mixture.

    Science.gov (United States)

    Li, Yonghao; Liu, Chenguang; Bai, Fengwu; Zhao, Xinqing

    2016-09-01

    Cellulase is a prerequisite for the bioconversion of lignocellulosic biomass, but its high cost presents the biggest challenge. In this article, low-cost mixture was produced from glucose through the transglycosylation reaction catalyzed by β-glucosidase for cellulase overproduction by Trichodema reesei RUT C30. As a result, cellulase titer of 90.3FPU/mL, which was more than 10 folds of that achieved with lactose as inducer, was achieved at 144h. Meanwhile, cellulase productivity was drastically increased to 627.1FPU/L/h, at least 3-5 folds higher than previously reported by the fungal species. The crude enzyme was further tested by hydrolyzing NaOH-pretreated corn stover with 15% solid loading, and 96.6g/L glucose was released with 92.6% sugar yield at 96h and 44.8g/L ethanol was obtained.

  11. Toward a sustainable biorefinery using high-gravity technology

    DEFF Research Database (Denmark)

    Xiros, Charilaos; Janssen, Matty; Bystrom, Roberth

    2017-01-01

    The realization of process solutions for a sustainable bioeconomy depends on the efficient processing of biomass. High-gravity technology is one important alternative to realizing such solutions. The aims of this work were to expand the knowledge-base on lignocellulosic bioconversion processes...... at high solids content, to advance the current technologies for production of second-generation liquid biofuels, to evaluate the environmental impact of the proposed process by using life cycle assessment (LCA), and to develop and present a technically, economically, and environmentally sound process...... using wheat straw and spruce as interesting Nordic raw materials. During the project, the main scientific, economic, and technical challenges of such a process were identified. Integrated solutions to these challenges were proposed and tested experimentally, using wheat straw and spruce wood at a dry...

  12. Intermediate-Scale High-Solids Anaerobic Digestion System Operational Development

    Energy Technology Data Exchange (ETDEWEB)

    Rivard, C. J.

    1995-02-01

    Anaerobic bioconversion of solid organic wastes represents a disposal option in which two useful products may be produced, including a medium Btu fuel gas (biogas) and a compost-quality organic residue. The application of high-solids technology may offer several advantages over conventional low-solids digester technology. The National Renewable Energy Laboratory (NREL) has developed a unique digester system capable of uniformly mixing high-solids materials at low cost. During the first 1.5 years of operation, a variety of modifications and improvements were instituted to increase the safety, reliability, and performance of the system. Those improvements, which may be critical in further scale-up efforts using ,the NREL high-solids digester design are detailed in this report.

  13. Nitrile-converting enzymes as a tool to improve biocatalysis in organic synthesis: recent insights and promises.

    Science.gov (United States)

    Gong, Jin-Song; Shi, Jin-Song; Lu, Zhen-Ming; Li, Heng; Zhou, Zhe-Min; Xu, Zheng-Hong

    2017-02-01

    Nitrile-converting enzymes, including nitrilase and nitrile hydratase (NHase), have received increasing attention from researchers of industrial biocatalysis because of their critical role as a tool in organic synthesis of carboxylic acids and amides from nitriles. To date, these bioconversion approaches are considered as one of the most potential industrial processes using resting cells or purified enzymes as catalysts for production of food additives, pharmaceutical, and agrochemical precursors. This review focuses on the distribution and catalytic mechanism research of nitrile-converting enzymes in recent years. Molecular biology aspects to improve the biocatalytic performance of microbial nitrilase and NHase are demonstrated. The process developments of microbial nitrilase and NHase for organic synthesis are also discussed.

  14. Effects of Chirality on the Antifungal Potency of Methylated Succinimides Obtained by Aspergillus fumigatus Biotransformations. Comparison with Racemic Ones

    Directory of Open Access Journals (Sweden)

    Susana Zacchino

    2013-05-01

    Full Text Available Eighteen (3R and (3R,4R-N-phenyl-, N-phenylalkyl and N-arylsuccinimides were prepared with high enantioselectivity by biotransformation of maleimides with A. fumigatus. This environmentally friendly, clean and economical procedure was performed by the whole-cell fungal bioconversion methodology. Their corresponding eighteen racemic succinimides were prepared instead by synthetic methods. Both, the racemic and the chiral succinimides were tested simultaneously by the microbroth dilution method of CLSI against a panel of human opportunistic pathogenic fungi of clinical importance. Chiral succinimides showed higher antifungal activity than the corresponding racemic ones and the differences in activity were established by statistical methods. The bottlenecks for developing chiral drugs are how to obtain them through a low-cost procedure and with high enantiomeric excess. Results presented here accomplish both these objectives, opening an avenue for the development of asymmetric succinimides as new antifungal drugs for pharmaceutical use.

  15. A novel anaerobic co-culture system for bio-hydrogen production from sugarcane bagasse.

    Science.gov (United States)

    Cheng, Jingrong; Zhu, Mingjun

    2013-09-01

    A novel co-culture of Clostridium thermocellum and Thermoanaerobacterium aotearoense with pretreated sugarcane bagasse (SCB) under mild alkali conditions for bio-hydrogen production was established, exhibiting a cost-effective and synergetic advantage in bio-hydrogen production over monoculture of C. thermocellum or T. aotearoense with untreated SCB. The optimized pretreatment conditions were established to be 3% NaOH, and a liquid to solid ratio of 25:1 at 80°C for 3h. A final hydrogen production of 50.05±1.51 mmol/L was achieved with 40 g/L pretreated SCB at 55°C. The established co-culture system provides a novel consolidated bio-processing strategy for bioconversion of SCB to bio-hydrogen.

  16. Fabricating polystyrene fiber-dehydrogenase assemble as a functional biocatalyst.

    Science.gov (United States)

    An, Hongjie; Jin, Bo; Dai, Sheng

    2015-01-01

    Immobilization of the enzymes on nano-structured materials is a promising approach to enhance enzyme stabilization, activation and reusability. This study aimed to develop polystyrene fiber-enzyme assembles to catalyze model formaldehyde to methanol dehydrogenation reaction, which is an essential step for bioconversion of CO2 to a renewable bioenergy. We fabricated and modified electrospun polystyrene fibers, which showed high capability to immobilize dehydrogenase for the fiber-enzyme assembles. Results from evaluation of biochemical activities of the fiber-enzyme assemble showed that nitriation with the nitric/sulfuric acid ratio (v/v, 10:1) and silanization treatment delivered desirable enzyme activity and long-term storage stability, showing great promising toward future large-scale applications.

  17. Comparison of Ultrasonic and CO2 Laser Pretreatment Methods on Enzyme Digestibility of Corn Stover

    Directory of Open Access Journals (Sweden)

    Li-Li Zuo

    2012-03-01

    Full Text Available To decrease the cost of bioethanol production, biomass recalcitrance needs to be overcome so that the conversion of biomass to bioethanol becomes more efficient. CO2 laser irradiation can disrupt the lignocellulosic physical structure and reduce the average size of fiber. Analyses with Fourier transform infrared spectroscopy, specific surface area, and the microstructure of corn stover were used to elucidate the enhancement mechanism of the pretreatment process by CO2 laser irradiation. The present work demonstrated that the CO2 laser had potential to enhance the bioconversion efficiency of lignocellulosic waste to renewable bioethanol. The saccharification rate of the CO2 laser pretreatment was significantly higher than ultrasonic pretreatment, and reached 27.75% which was 1.34-fold of that of ultrasonic pretreatment. The results showed the impact of CO2 laser pretreatment on corn stover to be more effective than ultrasonic pretreatment.

  18. Coal liquefaction: A research and development needs assessment: Final report, Volume II

    Energy Technology Data Exchange (ETDEWEB)

    Schindler, H.D.; Burke, F.P.; Chao, K.C.; Davis, B.H.; Gorbaty, M.L.; Klier, K.; Kruse, C.W.; Larsen, J.W.; Lumpkin, R.E.; McIlwain, M.E.; Wender, I.; Stewart, N.

    1989-03-01

    Volume II of this report on an assessment of research needs for coal liquefaction contains reviews of the five liquefaction technologies---direct, indirect, pyrolysis, coprocessing, and bioconversion. These reviews are not meant to be encyclopedic; several outstanding reviews of liquefaction have appeared in recent years and the reader is referred to these whenever applicable. Instead, these chapters contain reviews of selected topics that serve to support the panel's recommendations or to illustrate recent accomplishments, work in progress, or areas of major research interest. At the beginning of each of these chapters is a brief introduction and a summary of the most important research recommendations brought out during the panel discussions and supported by the material presented in the review. A review of liquefaction developments outside the US is included. 594 refs., 100 figs., 60 tabs.

  19. Effects of ensilage on storage and enzymatic degradability of sugar beet pulp.

    Science.gov (United States)

    Zheng, Yi; Yu, Chaowei; Cheng, Yu-Shen; Zhang, Ruihong; Jenkins, Bryan; VanderGheynst, Jean S

    2011-01-01

    Ensiling was investigated for the long-term storage of Sugar Beet Pulp (SBP). Eight strains of lactic acid bacteria (LAB) and a non-inoculated control were screened based on their ability to rapidly reduce pH, produce a large amount of lactic acid and inhibit undesirable fermentations. Lactobacillus brevis B-1836 (LAB #120), Lactobacillus fermentum NRRL B-4524 (LAB #137) and a non-inoculated control were selected for further research to determine the effects of LAB inoculation level and packing density on SBP silage quality and sugar yield upon enzymatic hydrolysis. Both SBP preservation and prevention of cellulose and hemicellulose loss were better when SBP was treated with LAB #137 compared to LAB #120 and the non-inoculated control. Additionally, the ensiling process was found to significantly improve the enzymatic digestibility of SBP by as much as 35%. The results suggest that ensiling may be a promising technology for SBP stabilization and pretreatment for bioconversion to products.

  20. Comparison of bamboo green, timber and yellow in sulfite, sulfuric acid and sodium hydroxide pretreatments for enzymatic saccharification.

    Science.gov (United States)

    Li, Zhiqiang; Jiang, Zehui; Fei, Benhua; Cai, Zhiyong; Pan, Xuejun

    2014-01-01

    The response and behavior of bamboo green, timber, and yellow of moso bamboo (Phyllostachys heterocycla) to three pretreatments, sulfite (SPORL), dilute acid (DA), and alkali (NaOH), were investigated and compared with varied chemical loadings at 180°C for 30 min with a 6.25:1 (v/w) liquor-to-bamboo ratio. All the pretreatments improved the enzymatic digestibility of bamboo substrates. Under the investigated conditions, the DA pretreatment achieved better enzymatic digestibility, but had lower sugar recovery yield, and formed more fermentation inhibitors. The results suggested that the SPORL pretreatment be able to generate more readily digestible bamboo substrate with higher sugar yield and fewer fermentation inhibitors than the corresponding DA pretreatment if hemicelluloses are sufficiently removed by adding more acid to bring down the pretreatment pH. Bamboo timber had higher sugar content and better enzymatic digestibility and therefore was a better feedstock for bioconversion than bamboo green and yellow.

  1. Advances in the enzymatic production of L-hexoses.

    Science.gov (United States)

    Chen, Ziwei; Zhang, Wenli; Zhang, Tao; Jiang, Bo; Mu, Wanmeng

    2016-08-01

    Rare sugars have recently drawn attention because of their potential applications and huge market demands in the food and pharmaceutical industries. All L-hexoses are considered rare sugars, as they rarely occur in nature and are thus very expensive. L-Hexoses are important components of biologically relevant compounds as well as being used as precursors for certain pharmaceutical drugs and thus play an important role in the pharmaceutical industry. Many general strategies have been established for the synthesis of L-hexoses; however, the only one used in the biotechnology industry is the Izumoring strategy. In hexose Izumoring, four entrances link the D- to L-enantiomers, ketose 3-epimerases catalyze the C-3 epimerization of L-ketohexoses, and aldose isomerases catalyze the specific bioconversion of L-ketohexoses and the corresponding L-aldohexoses. In this article, recent studies on the enzymatic production of various L-hexoses are reviewed based on the Izumoring strategy.

  2. 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......-AD) wasused to accelerate methane production for energy recovery from WAS. Carbon bioconversion wasaccelerated by ME producing H2 at the cathode. MPR was enhanced to 91.8 gCH4/m3 reactor/d in themicrobial electrolysis ME-AD reactor, thus improving the rate by 3 times compared to control conditions (30.6 gCH4......-AD reactor allowed to significantly enhance carbon degradation and methaneproduction from WAS....

  3. Mechanism and Anticancer Activity of the Metabolites of the Endophytic Fungi Eucommia ulmoides Oliv.

    Science.gov (United States)

    Li, Qi; Zhang, Yan; Shi, Junling; Wang, Yilin; Zhao, Haobin; Shao, Dongyan; Huang, Qingsheng; Yang, Hui; Jin, Mingling

    2016-09-22

    Pinoresinol (Pin) and pinoresinol monoglucoside (PMG) are plant-derived lignan molecules with multiple functions. We showed previously that the endophytic fungus Eucommiaulmoides Oliverendophytic Phomopsis sp. XP-8 is able to produce Pin and PMG. Cultured XP-8 showed inhibition on HepG-2 and K562 cells and the major effective compounds were identified. The fungal culture significantly inhibited the activities of HepG-2 and K562 cells by decreasing their viability and inducing apoptosis via up-regulating the expression of apoptosis-related genes. XP-8 also significantly inhibited the adhesion and migration of HepG-2 cells by blocking MMP-9 expression. Pin and pinoresinol monoglucoside were isolated from the growth culture and shown to be the major effective components for inhibition. These results support the potential application of XP-8 for the production of anti-tumor products by the bioconversion of glucose.

  4. Effect of nitrogen content on methane production by the marine algae Gracilaria tikvahiae and Ulva sp

    Energy Technology Data Exchange (ETDEWEB)

    Habig, C.; DeBusk, T.A.; Ryther, J.H.

    1984-01-01

    The rhodophyte Gracilaria tikvahiae and the chlorophyte Ulva sp. were grown under three different concentrations of tissue nitrogen. Each was then digested in batch-mode fermentation experiments. Both biogas and methane production were initially greater in Ulva but persisted longer in Gracilaria, resulting in similar performances for the two species over the entire time course of the experiment. Low-nitrogen Gracilaria contained more volatile solids and produced more biogas and methane per unit dry weight than did higher nitrogen plants, but about the same gas production per unit volatile solids. However, low nitrogen Ulva consistently out-performed the high nitrogen plants in gas production per unit volatile solids, total volatile solids, total volatile solids reduction, and bioconversion efficiency. These results, in contrast with those found in higher plants, probably reflect the low fiber, high soluble carbohydrate levels of nitrogen-deficient seaweeds in general and of Ulva in particular. 18 references, 2 figures, 4 tables.

  5. Solar Energy: Its Technologies and Applications

    Science.gov (United States)

    Auh, P. C.

    1978-06-01

    Solar heat, as a potential source of clean energy, is available to all of us. Extensive R and D efforts are being made to effectively utilize this renewable energy source. A variety of different technologies for utilizing solar energy have been proven to be technically feasible. Here, some of the most promising technologies and their applications are briefly described. These are: Solar Heating and Cooling of Buildings (SHACOB), Solar Thermal Energy Conversion (STC), Wind Energy Conversion (WECS), Bioconversion to Fuels (BCF), Ocean Thermal Energy Conversion (OTEC), and Photovoltaic Electric Power Systems (PEPS). Special emphasis is placed on the discussion of the SHACOB technologies, since the technologies are being expeditiously developed for the near commercialization.

  6. The biomass like renewable energy in the future. Futuro de la biomasa como energia renovable alternativo de futuro

    Energy Technology Data Exchange (ETDEWEB)

    Perez Peces, J. (INTECSA. Madrid (Spain))

    1993-01-01

    The energetic contribution of biomass in EC and worldwide figures represents a 14% of the whole demand. For developing countries this figure goes up to 35% and can be a source of employment for manpower decreasing in other sectors. At European level the CEC are promoting research areas through JOULE and LEBEN programs. Current European policy with big subsidies for intensive agricultural production has penalized forest and biomass production. Reforestation and biomass energetics crops are going to be a new strategy with 20 million Ha of agricultural soil transformed and between 10 and 20 million ha of marginal soil transformed. Biomass will be promoted keeping in mind environmental benefits like compost production for soil conditioning. A review of the different biomass sources and treatment techniques (bioconversion, thermal conversion and biodigestion), as well as environmental aspects are given.

  7. Low-temperature conversion of high-moisture biomass: Topical report, January 1984--January 1988

    Energy Technology Data Exchange (ETDEWEB)

    Sealock, L.J. Jr.; Elliott, D.C.; Butner, R.S.; Neuenschwander, G.G.

    1988-10-01

    Pacific Northwest Laboratory (PNL) is developing a low-temperature, catalytic process that converts high-moisture biomass feedstocks and other wet organic substances to useful gaseous and liquid fuels. The advantage of this process is that it works without the need for drying or dewatering the feedstock. Conventional thermal gasification processes, which require temperatures above 750/degree/C and air or oxygen for combustion to supply reaction heat, generally cannot utilize feedstocks with moisture contents above 50 wt %, as the conversion efficiency is greatly reduced as a result of the drying step. For this reason, anaerobic digestion or other bioconversion processes traditionally have been used for gasification of high-moisture feedstocks. However, these processes suffer from slow reaction rates and incomplete carbon conversion. 50 refs., 21 figs., 22 tabs.

  8. Interactions of a lignin-rich fraction from brewer's spent grain with gut microbiota in vitro.

    Science.gov (United States)

    Niemi, Piritta; Aura, Anna-Marja; Maukonen, Johanna; Smeds, Annika I; Mattila, Ismo; Niemelä, Klaus; Tamminen, Tarja; Faulds, Craig B; Buchert, Johanna; Poutanen, Kaisa

    2013-07-10

    Lignin is a constituent of plant cell walls and thus is classified as part of dietary fiber. However, little is known about the role of lignin in gastrointestinal fermentation. In this work, a lignin-rich fraction was prepared from brewer's spent grain and subjected to an in vitro colon model to study its potential bioconversions and interactions with fecal microbiota. No suppression of microbial conversion by the fraction was observed in the colon model, as measured as short-chain fatty acid production. Furthermore, no inhibition on the growth was observed when the fraction was incubated with strains of lactobacilli and bifidobacteria. In fact, the lignin-rich fraction enabled bifidobacteria to survive longer than with glucose. Several transiently appearing phenolic compounds, very likely originating from lignin, were observed during the fermentation. This would indicate that the gut microbiota was able to partially degrade lignin and metabolize the released compounds.

  9. Enzymatic Transesterification of Ethyl Ferulate with Fish Oil and Its Optimization by Response Surface Methodology

    DEFF Research Database (Denmark)

    Yang, Zhiyong; Glasius, Marianne; Xu, Xuebing

    2012-01-01

    The enzymatic transesterification of ethyl ferulate (EF) with cod liver fish oil was investigated with Novozym 435 as catalyst under solvent-free conditions. The purpose of the study is to evaluate the synthesis system for production of feruloyl fish oil in industry. The modified HPLC method...... was firstly set up to characterise the reaction products together with HPLC-ESI-MS. The adding of glycerol to the system on the profile of feruloyl acylglycerol species was investigated in terms of transesterification performance. The bioconversion rate of EF can be significantly increased with increased...... formation of feruloyl fish oil products as well when appropriate amount of glycerol was present in the reaction. Therefore, the addition of equivalent molar amount of glycerol to EF was decided for the practical optimization of the system. The mutual effects of temperature (40 to 70 oC), reaction time (1...

  10. Pilot-scale gasification of municipal solid wastes by high-rate and two-phase anaerobic digestion (TPAD).

    Science.gov (United States)

    Ghosh, S; Henry, M P; Sajjad, A; Mensinger, M C; Arora, J L

    2000-01-01

    Bioconversion of municipal solid waste-sludge blend by conventional high-rate and two-phase anaerobic digestion was studied. RDF (refused-derived fuel)-quality feed produced in a Madison, Wisconsin, USA, MRF (materials-recovery facility) was used. High-rate digestion experiments were conducted with bench-scale digesters under target operating conditions developed from an economic feasibility study. The effects of digestion temperature, RDF content of digester feed, HRT, loading rate, RDF particle size, and RDF pretreatment with cellulase or dilute solutions of NaOH or lime on digester performance were studied. A pilot-scale two-phase digestion plant was operated with 80:20 (weight ratio) RDF-sludge blends to show that this process exhibited a higher methane yield, and produced a higher methane-content digester gas than those obtained by single-stage, high-rate anaerobic digestion.

  11. Biosynthesis of glycosylated derivatives of tylosin in Streptomyces venezuelae.

    Science.gov (United States)

    Han, Ah Reum; Park, Sung Ryeol; Park, Je Won; Lee, Eun Yeol; Kim, Dong-Myung; Kim, Byung-Gee; Yoon, Yeo Joon

    2011-06-01

    Streptomyces venezuelae YJ028, bearing a deletion of the entire biosynthetic gene cluster encoding the pikromycin polyketide synthases and desosamine biosynthetic enzymes, was used as a bioconversion system for combinatorial biosynthesis of glycosylated derivatives of tylosin. Two engineered deoxysugar biosynthetic pathways for the biosynthesis of TDP-3-O-demethyl-D-chalcose or TDP-Lrhamnose in conjunction with the glycosyltransferaseauxiliary protein pair DesVII/DesVIII were expressed in a S. venezuelae YJ028 mutant strain. Supplementation of each mutant strain capable of producing TDP-3-O-demethyl- D-chalcose or TDP-L-rhamnose with tylosin aglycone tylactone resulted in the production of the 3-O-demethyl- D-chalcose, D-quinovose, or L-rhamnose-glycosylated tylactone.

  12. Extrusion Pretreatment of Lignocellulosic Biomass: A Review

    Directory of Open Access Journals (Sweden)

    Jun Zheng

    2014-10-01

    Full Text Available Bioconversion of lignocellulosic biomass to bioethanol has shown environmental, economic and energetic advantages in comparison to bioethanol produced from sugar or starch. However, the pretreatment process for increasing the enzymatic accessibility and improving the digestibility of cellulose is hindered by many physical-chemical, structural and compositional factors, which make these materials difficult to be used as feedstocks for ethanol production. A wide range of pretreatment methods has been developed to alter or remove structural and compositional impediments to (enzymatic hydrolysis over the last few decades; however, only a few of them can be used at commercial scale due to economic feasibility. This paper will give an overview of extrusion pretreatment for bioethanol production with a special focus on twin-screw extruders. An economic assessment of this pretreatment is also discussed to determine its feasibility for future industrial cellulosic ethanol plant designs.

  13. Transgalactosylation of lactose for synthesis of galacto-oligosaccharides using Kluyveromyces marxianus NCIM 3551.

    Science.gov (United States)

    Srivastava, Anita; Mishra, Saroj; Chand, Subhash

    2015-06-25

    Among a number of yeast strains screened for whole cell transgalactosylating activity, Kluyveromyces marxianus NCIM 3551 was found to be most suitable biocatalyst for production of galacto-oligosaccharides (GOS). Cell permeabilization lead to an efficient bioconversion by β-galactosidase resulting in synthesis of GOS. A maximum GOS yield of 36% (w/w) of total sugars was achieved and the products consisted of tri- and tetra-galacto-oligosaccharides. A lactose conversion rate of 80% and productivity of 24g/L/h was obtained under the optimum conditions at lactose concentration of 20% (w/v), temperature 40°C, pH 6.5 and enzyme units after 3h of reaction time. Tetrasaccharides were the main component of the reaction mixture. The products were quantitated by HPLC and structurally characterized by mass spectrometry.

  14. Simultaneous saccharification and fermentation of cellulose in a CSTR type fermenter by thermotolerat Kluyveromyces marxianus

    Energy Technology Data Exchange (ETDEWEB)

    Campos, I. del; Ballesteros, I.; Ballesteros, M.

    2001-07-01

    Production of ethanol from lignocellulose biomass could provide a renewable source of premium transportation fuels that could reduce or eliminate the European dependence on mounting imports od petroleum from unstable sources. Enzymatic hydrolysis of cellulose is a key step in the bioconversion of lifnocellulosic biomass to fuel ethanol. the reaction is characterised by the synergistic effect of multi-enzyme systems and the adsorption of enzyme to the substrate is needed. The several end-product inhibition of cellulase action by the accumulation of both cellobiose and glucose can greatly limit concentration, yield, and reaction rate for enzymatic hydrolysis. This bottleneck can be overcome by the simultaneous saccharification and fermentation (SSF) Process, in which the enzymatic hydrolysis and yeast fermentation steps are combined in one vessel. In the SSP process the end-product inhibition of the enzyme is eliminated, therefore can be achieved high yields, rates and concentrations of ethanol. (Author)

  15. Role of bifidobacteria in the hydrolysis of chlorogenic acid.

    Science.gov (United States)

    Raimondi, Stefano; Anighoro, Andrew; Quartieri, Andrea; Amaretti, Alberto; Tomás-Barberán, Francisco A; Rastelli, Giulio; Rossi, Maddalena

    2015-02-01

    This study aimed to explore the capability of potentially probiotic bifidobacteria to hydrolyze chlorogenic acid into caffeic acid (CA), and to recognize the enzymes involved in this reaction. Bifidobacterium strains belonging to eight species occurring in the human gut were screened. The hydrolysis seemed peculiar of Bifidobacterium animalis, whereas the other species failed to release CA. Intracellular feruloyl esterase activity capable of hydrolyzing chlorogenic acid was detected only in B. animalis. In silico research among bifidobacteria esterases identified Balat_0669 as the cytosolic enzyme likely responsible of CA release in B. animalis. Comparative modeling of Balat_0669 and molecular docking studies support its role in chlorogenic acid hydrolysis. Expression, purification, and functional characterization of Balat_0669 in Escherichia coli were obtained as further validation. A possible role of B. animalis in the activation of hydroxycinnamic acids was demonstrated and new perspectives were opened in the development of new probiotics, specifically selected for the enhanced bioconversion of phytochemicals into bioactive compounds.

  16. Hazard remediation and recycling of tea industry and paper mill bottom ash through vermiconversion.

    Science.gov (United States)

    Goswami, Linee; Patel, Arbind Kumar; Dutta, Ganesh; Bhattacharyya, Pradip; Gogoi, Nirmali; Bhattacharya, Satya Sundar

    2013-07-01

    Considerable amount of bottom ash (BA) is produced by tea and paper factories in Northeast India. This significantly deteriorates soil and surface water quality through rapid acidification, releasing sulfur compounds and heavy metals. The present investigation endeavoured to convert this waste to organic manure through vermicomposting by Eisenia fetida. Substantial increment in bioavailability of N, P, K, Fe, Mn and Zn along with remarkable decline in toxic metal like Cr due to vermicomposting was noteworthy. Furthermore, vermicomposted mixtures of Tea Factory BA (TFBA) or Paper Mill BA (PMBA) with organic matter (OM) attributed profuse pod yield of French Bean (Phaseolus vulgaris L.). Hence, bioconversion of TFBA and PMBA is highly feasible through vermicomposting and the converted materials can be utilized as potential organic fertilizer.

  17. Genetic engineering of Geobacillus spp.

    Science.gov (United States)

    Kananavičiūtė, Rūta; Čitavičius, Donaldas

    2015-04-01

    Members of the genus Geobacillus are thermophiles that are of great biotechnological importance, since they are sources of many thermostable enzymes. Because of their metabolic versatility, geobacilli can be used as whole-cell catalysts in processes such as bioconversion and bioremediation. The effective employment of Geobacillus spp. requires the development of reliable methods for genetic engineering of these bacteria. Currently, genetic manipulation tools and protocols are under rapid development. However, there are several convenient cloning vectors, some of which replicate autonomously, while others are suitable for the genetic modification of chromosomal genes. Gene expression systems are also intensively studied. Combining these tools together with proper techniques for DNA transfer, some Geobacillus strains were shown to be valuable producers of recombinant proteins and industrially important biochemicals, such as ethanol or isobutanol. This review encompasses the progress made in the genetic engineering of Geobacillus spp. and surveys the vectors and transformation methods that are available for this genus.

  18. Simultaneous utilization of cellobiose, xylose, and acetic acid from lignocellulosic biomass for biofuel production by an engineered yeast platform.

    Science.gov (United States)

    Wei, Na; Oh, Eun Joong; Million, Gyver; Cate, Jamie H D; Jin, Yong-Su

    2015-06-19

    The inability of fermenting microorganisms to use mixed carbon components derived from lignocellulosic biomass is a major technical barrier that hinders the development of economically viable cellulosic biofuel production. In this study, we integrated the fermentation pathways of both hexose and pentose sugars and an acetic acid reduction pathway into one Saccharomyces cerevisiae strain for the first time using synthetic biology and metabolic engineering approaches. The engineered strain coutilized cellobiose, xylose, and acetic acid to produce ethanol with a substantially higher yield and productivity than the control strains, and the results showed the unique synergistic effects of pathway coexpression. The mixed substrate coutilization strategy is important for making complete and efficient use of cellulosic carbon and will contribute to the development of consolidated bioprocessing for cellulosic biofuel. The study also presents an innovative metabolic engineering approach whereby multiple substrate consumption pathways can be integrated in a synergistic way for enhanced bioconversion.

  19. Marine macroalgae: an untapped resource for producing fuels and chemicals.

    Science.gov (United States)

    Wei, Na; Quarterman, Josh; Jin, Yong-Su

    2013-02-01

    As world energy demand continues to rise and fossil fuel resources are depleted, marine macroalgae (i.e., seaweed) is receiving increasing attention as an attractive renewable source for producing fuels and chemicals. Marine plant biomass has many advantages over terrestrial plant biomass as a feedstock. Recent breakthroughs in converting diverse carbohydrates from seaweed biomass into liquid biofuels (e.g., bioethanol) through metabolic engineering have demonstrated potential for seaweed biomass as a promising, although relatively unexplored, source for biofuels. This review focuses on up-to-date progress in fermentation of sugars from seaweed biomass using either natural or engineered microbial cells, and also provides a comprehensive overview of seaweed properties, cultivation and harvesting methods, and major steps in the bioconversion of seaweed biomass to biofuels.

  20. Biorefineries of carbon dioxide: From carbon capture and storage (CCS) to bioenergies production.

    Science.gov (United States)

    Cheah, Wai Yan; Ling, Tau Chuan; Juan, Joon Ching; Lee, Duu-Jong; Chang, Jo-Shu; Show, Pau Loke

    2016-09-01

    Greenhouse gas emissions have several adverse environmental effects, like pollution and climate change. Currently applied carbon capture and storage (CCS) methods are not cost effective and have not been proven safe for long term sequestration. Another attractive approach is CO2 valorization, whereby CO2 can be captured in the form of biomass via photosynthesis and is subsequently converted into various form of bioenergy. This article summarizes the current carbon sequestration and utilization technologies, while emphasizing the value of bioconversion of CO2. In particular, CO2 sequestration by terrestrial plants, microalgae and other microorganisms are discussed. Prospects and challenges for CO2 conversion are addressed. The aim of this review is to provide comprehensive knowledge and updated information on the current advances in biological CO2 sequestration and valorization, which are essential if this approach is to achieve environmental sustainability and economic feasibility.

  1. SO2-catalyzed steam pretreatment enhances the strength and stability of softwood pellets.

    Science.gov (United States)

    Tooyserkani, Zahra; Kumar, Linoj; Sokhansanj, Shahab; Saddler, Jack; Bi, Xiaotao T; Lim, C Jim; Lau, Anthony; Melin, Staffan

    2013-02-01

    Densification can partially resolve the logistical challenges encountered when large volumes of biomass are required for bioconversion processes to benefit from economies-of-scale. Despite the higher bulk density of pellets, their lower mechanical strength and sensitivity to moisture are still recurring issues hindering long term transportation and storage. In this study, we have evaluated the potential benefits of SO(2)-catalyzed steam treatment to achieve both the needed size reduction prior to pelletization while improving the stability of the produced pellets. This pretreatment substantially reduced the particle size of the woodchips eliminating any further grinding. The treated pellets had a higher density and exhibited a two-time higher mechanical strength compared to untreated pellets. Despite a higher moisture adsorption capacity, treated pellets remained intact even under highly humid conditions. The high heating values, low ash content and good overall carbohydrate recovery of treated pellets indicated their potential suitability for both biochemical and thermochemical applications.

  2. Colloidal processing of porous membranes for biogas lighting; Processamento coloidal de membranas porosas para iIluminacao por biogas

    Energy Technology Data Exchange (ETDEWEB)

    Santos, S.C.; Mello-Castanho, S.R.H., E-mail: silascs@ipen.br, E-mail: srmello@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo (Brazil)

    2011-07-01

    Nowadays the urban garbage is a great economic and environmental challenge in the whole world. Solid wastes stored in continuous form in landfills are subject of natural variables, transforming them (by bioconversion) in biogas which can be used as energy font in many applications as urban lighting. However, technology to produce it has not been stabilized in Brazil yet. So, in this work porous membranes of rare earth -yttria concentrate (Ctr-Y) with potential to be used as biogas mantles were produced by replica method. The effect of solids and binder concentration on rheological behavior of Ctr-Y suspensions were evaluated by flux curves. According to the results, suspensions with 25vol% and 0,2wt% of CMC showed adequated viscosity and rheological behavior (thixotropy) for replica method. Sintered samples presented the same morphology of template and good handle strength. (author)

  3. Methane production from the red seaweed gracilaria tikvahiae

    Energy Technology Data Exchange (ETDEWEB)

    Hanisak, M.D.

    1981-01-01

    Stable continuous anaerobic digestion of the title seaweed was maintained in large (120 L) digesters for more than 20 months, with an average gas (60% CH4) production of 0.4 L/g volatile solids. The average bioconversion efficiency was approximately 48%. When the retention time, t, was increased (i.e., loading rate decreased) from 10 to 60 days the total production of biogas and CH4 (as well as the percent CH4 and the reduction of total volatile solids) increased to maximum at t = 30 days and decreased at t = 60 days. Biogas and CH4 production on the basis of volatile solids added increased to less than or equal to 60 days, as did the percent volatile solids reduction. The pH in the digesters increased with increasing t.

  4. Effect of nitrogen content on methane production by the marine algae gracilaria tikvahiae and ulva species

    Energy Technology Data Exchange (ETDEWEB)

    Habig, C.; De Busk, T.A.; Ryther, J.H.

    1984-01-01

    The rhodophyte Gracilaria tikvahiae and the chlorophyte Ulva species were grown under three different nitrogen enrichment regimes producing plants of each species with three different concentrations of tissue nitrogen. Each was then digested in batch-mode fermentation experiments. Both biogas and methane production were initially greater in Ulva but persisted longer in Gracilaria, resulting in similar performances for the two species over the entire time course of the experiment. Low-nitrogen Gracilaria contained more volatile solids and produced more biogas and methane per unit dry weight than did higher nitrogen plants, but about the same gas production per unit volatile solids. However, low nitrogen Ulva consistently out-performed the high nitrogen plants in gas production per unit volatile solids, total volatile solids reduction, and bioconversion efficiency. These results, in contrast with those found in higher plants, probably reflect the low fiber, high soluble carbohydrate levels of nitrogen-deficient seaweeds in general and of Ulva in particular.

  5. Novel strategy to improve vanillin tolerance and ethanol fermentation performances of Saccharomycere cerevisiae strains.

    Science.gov (United States)

    Zheng, Dao-Qiong; Jin, Xin-Na; Zhang, Ke; Fang, Ya-Hong; Wu, Xue-Chang

    2017-01-26

    The aim of this work was to develop a novel strategy for improving the vanillin tolerance and ethanol fermentation performances of Saccharomyces cerevisiae strains. Isogeneic diploid, triploid, and tetraploid S. cerevisiae strains were generated by genome duplication of haploid strain CEN.PK2-1C. Ploidy increments improved vanillin tolerance and diminished proliferation capability. Antimitotic drug methyl benzimidazol-2-ylcarbamate (MBC) was used to introduce chromosomal aberrations into the tetraploid S. cerevisiae strain. Interestingly, aneuploid mutants with DNA contents between triploid and tetraploid were more resistant to vanillin and showed faster ethanol fermentation rates than all euploid strains. The physiological characteristics of these mutants suggest that higher bioconversion capacities of vanillin and ergosterol contents might contribute to improved vanillin tolerance. This study demonstrates that genome duplication and MBC treatment is a powerful strategy to improve the vanillin tolerance of yeast strains.

  6. Biotransformation of flavone by CYP105P2 from Streptomyces peucetius.

    Science.gov (United States)

    Niraula, Narayan Prasad; Bhattarai, Saurabh; Lee, Na-Rae; Sohng, Jae Kyung; Oh, Tae-Jin

    2012-08-01

    Biocatalytic transfer of oxygen in isolated cytochrome P450 or whole microbial cells is an elegant and efficient way to achieve selective hydroxylation. Cytochrome P450 CYP105P2 was isolated from Streptomyces peucetius that showed a high degree of amino acid identity with hydroxylases. Previously performed homology modeling, and subsequent docking of the model with flavone, displayed a reasonable docked structure. Therefore, in this study, in a pursuit to hydroxylate the flavone ring, CYP105P2 was co-expressed in a two-vector system with putidaredoxin reductase (camA) and putidaredoxin (camB) from Pseudomonas putida for efficient electron transport. HPLC analysis of the isolated product, together with LCMS analysis, showed a monohydroxylated flavone, which was further established by subsequent ESI/MS-MS. A successful 10.35% yield was achieved with the whole-cell bioconversion reaction in Escherichia coli. We verified that CYP105P2 is a potential bacterial hydroxylase.

  7. Mulberry anthocyanin biotransformation by intestinal probiotics.

    Science.gov (United States)

    Cheng, Jing-Rong; Liu, Xue-Ming; Chen, Zhi-Yi; Zhang, You-Sheng; Zhang, Ye-Hui

    2016-12-15

    This study was designed to evaluate mulberry anthocyanins bioconversion traits for intestinal probiotics. Five intestinal beneficial bacteria were incubated with mulberry anthocyanins under anaerobic conditions at 37°C, and bacterial β-glucosidase activity and anthocyanin level were determined. Results demonstrated that all strains could convert mulberry anthocyanins to some extent. With high β-glucosidase production capacity, Streptococcus thermophiles GIM 1.321 and Lactobacillus plantarum GIM 1.35 degraded mulberry anthocyanins by 46.17% and 43.62%, respectively. Mulberry anthocyanins were mainly biotransformed to chlorogenic acid, crypto-chlorogenic acid, caffeic acid, and ferulic acid during the anaerobic process. Non-enzymatic deglycosylation of anthocyanins also occurred and approximately 19.42% of the anthocyanins were degraded within 48h by this method.

  8. Pretreatment methods for bioethanol production.

    Science.gov (United States)

    Xu, Zhaoyang; Huang, Fang

    2014-09-01

    Lignocellulosic biomass, such as wood, grass, agricultural, and forest residues, are potential resources for the production of bioethanol. The current biochemical process of converting biomass to bioethanol typically consists of three main steps: pretreatment, enzymatic hydrolysis, and fermentation. For this process, pretreatment is probably the most crucial step since it has a large impact on the efficiency of the overall bioconversion. The aim of pretreatment is to disrupt recalcitrant structures of cellulosic biomass to make cellulose more accessible to the enzymes that convert carbohydrate polymers into fermentable sugars. This paper reviews several leading acidic, neutral, and alkaline pretreatments technologies. Different pretreatment methods, including dilute acid pretreatment (DAP), steam explosion pretreatment (SEP), organosolv, liquid hot water (LHW), ammonia fiber expansion (AFEX), soaking in aqueous ammonia (SAA), sodium hydroxide/lime pretreatments, and ozonolysis are intensively introduced and discussed. In this minireview, the key points are focused on the structural changes primarily in cellulose, hemicellulose, and lignin during the above leading pretreatment technologies.

  9. Combined steam pretreatment and enzymatic hydrolysis of starch-free wheat fibers.

    Science.gov (United States)

    Palmarola-Adrados, Beatriz; Galbe, Mats; Zacchi, Guido

    2004-01-01

    Steam treatment of an industrial process stream, denoted starch-free wheat fiber, was investigated to improve the formation of monomeric sugars in subsequent enzymatic hydrolysis for further bioconversion into ethanol. The solid fraction in the process stream, derived from a combined starch and ethanol factory, was rich in arabinose (21.1%), xylose (30.1%), and glucose (18.6%), in the form of polysaccharides. Various conditions of steam pretreatment (170-220 degrees C for 5-30 min) were evaluated, and their effect was assessed by enzymatic hydrolysis with 2 g of Celluclast + Ultraflo mixture/100 g of starch-free fiber (SFF) slurry at 5% dry matter (DM). The highest overall sugar yield for the combined steam pretreatment and enzymatic hydrolysis, 52 g/100 g of DM of SFF, corresponding to 74% of the theoretical, was achieved with pretreatment at 190 degrees C for 10 min followed by enzymatic hydrolysis.

  10. Impact of diet on human intestinal microbiota and health.

    Science.gov (United States)

    Salonen, Anne; de Vos, Willem M

    2014-01-01

    Our intestinal microbiota is involved in the breakdown and bioconversion of dietary and host components that are not degraded and taken up by our own digestive system. The end products generated by our microbiota fuel our enterocytes and support growth but also have signaling functions that generate systemic immune and metabolic responses. Due to the immense metabolic capacity of the intestinal microbiota and its relatively high plasticity, there is great interest in identifying dietary approaches that allow intentional and predictable modulation of the microbiota. In this article, we review the current insights on dietary influence on the human intestinal microbiota based on recent high-throughput molecular studies and interconnections with health. We focus especially on the emerging data that identify the amount and type of dietary fat as significant modulators of the colonic microbiota and its metabolic output.

  11. Cyanobacterial biomass as carbohydrate and nutrient feedstock for bioethanol production by yeast fermentation

    DEFF Research Database (Denmark)

    Möllers, K Benedikt; Canella, D.; Jørgensen, Henning;

    2014-01-01

    Background: Microbial bioconversion of photosynthetic biomass is a promising approach to the generation of biofuels and other bioproducts. However, rapid, high-yield, and simple processes are essential for successful applications. Here, biomass from the rapidly growing photosynthetic marine...... cyanobacterium Synechococcus sp. PCC 7002 was fermented using yeast into bioethanol. Results: The cyanobacterium accumulated a total carbohydrate content of about 60% of cell dry weight when cultivated under nitrate limitation. The cyanobacterial cells were harvested by centrifugation and subjected to enzymatic...... cyanobacteria or microalgae. Importantly, as well as fermentable carbohydrates, the cyanobacterial hydrolysate contained additional nutrients that promoted fermentation. This hydrolysate is therefore a promising substitute for the relatively expensive nutrient additives (such as yeast extract) commonly used...

  12. Unconventional biomasses as feedstocks for production of biofuels and succinic acid in a biorefinery concept

    DEFF Research Database (Denmark)

    Gunnarsson, Ingólfur Bragi

    Biorefinery has the potential of displacing fossil fuels and oil-refinery based products. Within the biorefinery a palette of marketable commodities can be produced from biomass, including food, feed, biochemicals and biofuels. Which bioproducts are produced is largely dependent on the chemical....... The chemical composition of biomasses was determined in order to demonstrate their biorefinery potential. Bioethanol and biogas along with succinic acid production were the explored bioconversion routes, while potential production of other compounds was also investigated. Differences and changes in biomass...... biogas upgrading technologies deliver. Results obtained in this study constitute the first report for utilization of macroalgae, hemp and Jerusalem artichoke tuber biomass for fermentative succinic acid production. It was demonstrated that all biomasses are attractive biomass feedstocks for succinic acid...

  13. Cyanobacterial biomass as carbohydrate and nutrient feedstock for bioethanol production by yeast fermentation

    DEFF Research Database (Denmark)

    Möllers, K Benedikt; Canella, D.; Jørgensen, Henning

    2014-01-01

    Background: Microbial bioconversion of photosynthetic biomass is a promising approach to the generation of biofuels and other bioproducts. However, rapid, high-yield, and simple processes are essential for successful applications. Here, biomass from the rapidly growing photosynthetic marine......H was adjusted to the optimal value. The highest ethanol yield and concentration obtained was 0.27 g ethanol per g cell dry weight and 30 g ethanol L-1, respectively. About 90% of the glucose in the biomass was converted to ethanol. The cyanobacterial hydrolysate was rapidly fermented (up to 20 g ethanol L-1 day......-1) even in the absence of any other nutrient additions to the fermentation medium. Conclusions: Cyanobacterial biomass was hydrolyzed using a simple enzymatic treatment and fermented into ethanol more rapidly and to higher concentrations than previously reported for similar approaches using...

  14. Les énergies renouvelables. État de l'art et perspectives de développement

    Science.gov (United States)

    Bal, Jean-Louis; Chabot, Bernard

    2001-12-01

    Here are presented the renewable energies composed of all energy sources deriving directly or indirectly from the sun, including solar, wind and hydraulic energies as well as the energies available from bioconversion. These energies are characterised by the fact that they are inexhaustible but available only in limited quantities at a given place and time. They have only a very slight impact on the environment. The development of renewable energy sources in Europe will receive a strong stimulus in the coming decade by the adoption of a European directive on electricity from renewable sources, designed to foster compliance with the European commitments made in Kyoto. In France, the goal is to increase the portion of electrical energy from renewable sources from 15 to 21% by 2010.

  15. Producing hydrogen from wastewater sludge by Clostridium bifermentans.

    Science.gov (United States)

    Wang, C C; Chang, C W; Chu, C P; Lee, D J; Chang, B-V; Liao, C S

    2003-04-10

    Excess wastewater sludge collected from the recycling stream of an activated sludge process is biomass that contains large quantities of polysaccharides and proteins. However, relevant literature indicates that the bio-conversion of wastewater sludge to hydrogen is limited and therefore not economically feasible. This work examined the anaerobic digestion of wastewater sludge using a clostridium strain isolated from the sludge as inoculum. A much higher hydrogen yield than presented in the literature was obtained. Also, the effects of five pre-treatments-ultrasonication, acidification, sterilization, freezing/thawing and adding methanogenic inhibitor-on the production of hydrogen were examined. Freezing and thawing and sterilization increased the specific hydrogen yield by 1.5-2.5 times to that of untreated sludge, while adding an inhibitor and ultrasonication reduced the hydrogen yield.

  16. Converting Chemical Oxygen Demand (COD) of Cellulosic Ethanol Fermentation Wastewater into Microbial Lipid by Oleaginous Yeast Trichosporon cutaneum.

    Science.gov (United States)

    Wang, Juan; Hu, Mingshan; Zhang, Huizhan; Bao, Jie

    2017-01-27

    Cellulosic ethanol fermentation wastewater is the stillage stream of distillation column of cellulosic ethanol fermentation broth with high chemical oxygen demand (COD). The COD is required to reduce before the wastewater is released or recycled. Without any pretreatment nor external nutrients, the cellulosic ethanol fermentation wastewater bioconversion by Trichosporon cutaneum ACCC 20271 was carried out for the first time. The major components of the wastewater including glucose, xylose, acetic acid, ethanol, and partial of phenolic compounds could be utilized by T. cutaneum ACCC 20271. In a 3-L bioreactor, 2.16 g/L of microbial lipid accumulated with 55.05% of COD reduced after a 5-day culture of T. cutaneum ACCC 20271 in the wastewater. The fatty acid composition of the derived microbial lipid was similar with vegetable oil, in which it could be used as biodiesel production feedstock. This study will both solve the environmental problem and offer low-cost lipid feedstock for biodiesel production.

  17. Co-transformation of Panax major ginsenosides Rb₁ and Rg₁ to minor ginsenosides C-K and F₁ by Cladosporium cladosporioides.

    Science.gov (United States)

    Wu, Lunpeng; Jin, Yan; Yin, Chengri; Bai, Longlv

    2012-04-01

    Rb₁ and Rg₁ are the major ginsenosides in protopanaxadiol and protopanaxatriol. Their content in ginsenosides was 23.8 and 17.6%, respectively. A total of 22 isolates of β-glucosidase producing microorganisms were isolated from the soil of a ginseng field using Esculin-R2A agar. Among these isolates, the strain GH21 showed the strongest activities to convert ginsenoside Rb₁ and Rg₁ to minor ginsenosides compound-K and F₁, respectively. Ginsenosides Rb₁ and Rg₁ bioconversion rates were 74.2 and 89.3%, respectively. Meanwhile, the results demonstrated that the ginsenoside Rg₁ could change the biotransformation pathway of ginsenoside Rb₁ by inhibiting the formation of the intermediate metabolite gypenoside-XVII. GH21 was identified as a Cladosporium cladosporioides species based on the internal transcribed spacers (ITS) ITS1-5.8S-ITS2 rRNA gene sequences constructed phylogenetic trees.

  18. Studying the ability of Fusarium oxysporum and recombinant Saccharomyces cerevisiae to efficiently cooperate in decomposition and ethanolic fermentation of wheat straw

    DEFF Research Database (Denmark)

    Panagiotou, Gianni; Topakas, Evangelos; Moukouli, Maria

    2011-01-01

    by the addition of commercially available enzymes Celluclast® 1.5 L FG and Novozym® 188 in 3:1 ratio for the treatment of PWS, resulted in a 3-fold increase in the volumetric ethanol productivity without increasing the ethanol production significantly. By direct bioconversion of 110 kg m−3 dry matter of PWS......, ethanol concentration (4.9 kg m−3) and yield (40 g kg−1 of PWS) were similarly obtained by F. oxysporum and the mixed culture, while productivity rates as high as 34 g m−3 h−1 and 108 g m−3 h−1 were obtained by F. oxysporum and the mixed culture, respectively.......Fusarium oxysporum F3 alone or in mixed culture with Saccharomyces cerevisiae F12 were used to ferment carbohydrates of wet exploded pre-treated wheat straw (PWS) directly to ethanol. Both microorganisms were first grown aerobically to produce cell mass and thereafter fermented PWS to ethanol under...

  19. Energy from plants: problems and prospects

    Energy Technology Data Exchange (ETDEWEB)

    Khoshoo, T.N.

    1982-01-01

    This article contains the presidential address to the Section of Botany (VI). After an introduction and a brief account of the process and efficiency of photosynthesis, the address describes terrestrial and aquatic biomass, biological hydrogen production and bioconversion (the conversion of biomass and organic wastes into energy and also into fertilizers, food and chemicals). The section on terrestial biomass is with particular reference to India and examines fuel plantations, the possibility of covered energy farms (such as the growth of alfalfa in greenhouses), the production of agricultural alcohol, the use of vegetable oils as fuel, the production and use of jojoba (Simmondsia chinensis) wax, and hydrocarbon producing plants (rubber, Euphorbia spp., various Leguminosae etc.).

  20. Obtaining partial purified xylose reductase from Candida guilliermondii Obtenção de xilose redutase de Candida guilliermondii parcialmente purificada

    Directory of Open Access Journals (Sweden)

    Ester Junko Tomotani

    2009-09-01

    Full Text Available The enzymatic bioconversion of xylose into xylitol by xylose reductase (XR is an alternative for chemical and microbiological processes. The partial purified XR was obtained by using the following three procedures: an agarose column, a membrane reactor or an Amicon Ultra-15 50K Centrifugal Filter device at yields of 40%, 7% and 67%, respectively.A bioconversão enzimática da xilose em xilitol pela xilose redutase (XR é uma alternativa para as vias química e microbiológica. Avaliouse a purificação parcial da XR, utilizando os três seguintes procedimentos: uma coluna de agarose, um reator com membrana ou tubos de ultracentrifugação Amicon Ultra-15 50K, com rendimento de 40%, 7% ou 67%, respectivamente.

  1. Social metabolism in an agrarian region of Catalonia (Spain) in 1860-1870: Flows, energy balance and land use

    Energy Technology Data Exchange (ETDEWEB)

    Cusso, Xavier; Garrabou, Ramon [Barcelona Autonomous University (Spain); Tello, Enric [University of Barcelona (Spain)

    2006-06-10

    The energy balance of the 1860-1870 agrarian system in a Catalan county (Spain) shows a 1.41 energy return on energy inputs. This positive figure was achieved despite the high intensive Mediterranean organic agriculture then practiced and its unavoidable dependence on the inefficient livestock bioconversion of biomass to obtain manure and traction. The key feature was the integration between agricultural, pasture and forest lands mainly by means of livestock breeding. The study of past socio-metabolic flows helps to highlight the two sides that have led to a lower energy performance of the agrarian systems in the 20th century: (1) the injection of external energy subsidies coming from fossil fuels; and (2) the functional disconnection between the different land covers inside the whole agrarian ecosystem. This disconnection has brought about a much more inefficient land use from an ecological point of view. (author)

  2. Vermicomposting of source-separated human faeces by Eisenia fetida: effect of stocking density on feed consumption rate, growth characteristics and vermicompost production.

    Science.gov (United States)

    Yadav, Kunwar D; Tare, Vinod; Ahammed, M Mansoor

    2011-06-01

    The main objective of the present study was to determine the optimum stocking density for feed consumption rate, biomass growth and reproduction of earthworm Eisenia fetida as well as determining and characterising vermicompost quantity and product, respectively, during vermicomposting of source-separated human faeces. For this, a number of experiments spanning up to 3 months were conducted using soil and vermicompost as support materials. Stocking density in the range of 0.25-5.00 kg/m(2) was employed in different tests. The results showed that 0.40-0.45 kg-feed/kg-worm/day was the maximum feed consumption rate by E. fetida in human faeces. The optimum stocking densities were 3.00 kg/m(2) for bioconversion of human faeces to vermicompost, and 0.50 kg/m(2) for earthworm biomass growth and reproduction.

  3. Production, Identification, and Toxicity of (gamma)-Decalactone and 4-Hydroxydecanoic Acid from Sporidiobolus spp

    Science.gov (United States)

    Feron, G.; Dufosse, L.; Pierard, E.; Bonnarme, P.; Quere, J. L.; Spinnler, H.

    1996-01-01

    During the bioconversion of ricinoleic acid to (gamma)-decalactone under controlled pH conditions, Sporidiobolus salmonicolor produced only the lactone form, while Sporidiobolus ruinenii produced both the lactone form and a precursor. By using gas chromatography-mass spectrometry and gas chromatography-Fourier transform infrared analysis techniques, the precursor was identified as 4-hydroxydecanoic acid. The levels of production in the presence of high concentrations of ricinoleic acid methyl ester differed in the two Sporidiobolus species. This difference was due on the one hand to the high sensitivity of S. salmonicolor to the lactone and on the other hand to the high level of 4-hydroxydecanoic acid produced by S. ruinenii. 4-Hydroxydecanoic acid is much less toxic to the microorganisms than the lactone. In contrast to S. ruinenii, S. salmonicolor is not able to catabolize 4-hydroxydecanoic acid. PMID:16535376

  4. Research Progress on Production of Podophyllotoxin from Sinopodophyllum hexandrum

    Institute of Scientific and Technical Information of China (English)

    Liu Haijun; Xu Yan; Su Guoqing; Li Chunyan; Wang Li; Liu Yujun

    2004-01-01

    Podophyllotoxin is isolated mainly from the rhizomes of Podophyllum plants, and serves as the main precursor for synthesis of anticancer drugs, such as VP-16 and VM-26. VP-16 and VM-26 are used for curing lung cancer, testicular cancer, neuroblastoma, hepatoma and other tumors. However, these plants are all near-extinction species due to over-collection and their own biological characteristics. The chemical synthesis of podophyllotoxin is so complicated that its price is unbelievably high. This paper discusses the current status of the biosynthetic pathway of podophyllotoxin and that of the podophyllotoxin production using several biotechnological approaches such as plant organ cultures, plant cell cultures with both flasks and bioreactors, hairy root cultures, bioconversions and metabolic regulations.

  5. Simultaneous saccharification and fermentation of cassava waste for ethanol production

    Directory of Open Access Journals (Sweden)

    C. Pothiraj

    2015-03-01

    Full Text Available The efficiency of enzymatic and microbial saccharification of cassava waste for ethanol production was investigated and the effective parameters were optimized. The mixture of amylase and amyloglucosidase (AMG resulted in a significantly higher rate of saccharification (79.6% than the amylase alone (68.7%. Simultaneous saccharification and fermentation (SSF yielded 6.2 g L-1 ethanol representing 64.5% of the theoretical yield. Saccharification and fermentation using pure and co-cultures of fungal isolates including Rhizopus stolonifer, Aspergillus terreus, Saccharomyces diastaticus and Zymomonas mobilis revealed that the co-culture system involving S. diastaticus and Z. mobilis was highly suitable for the bio-conversion of cassava waste into ethanol, resulting in 20.4 g L-1 in 36 h (91.3% of the theoretical yield.

  6. Metabolic Engineering for Expanding the Substrate Range of Yarrowia lipolytica.

    Science.gov (United States)

    Ledesma-Amaro, Rodrigo; Nicaud, Jean-Marc

    2016-10-01

    Economically viable biotechnology processes must be characterized by a favorable ratio between the production costs and the product market price. In the bioproduction of bulk chemicals, costs must be minimized so that the process is competitive relative to petroleum-based production. The substrate costs must thus be reduced by employing inexpensive carbon sources, such as industrial wastes. Unfortunately, the most convenient microorganisms for a bioconversion are typically unable to degrade such substrates. Fortunately, the discovery of new enzymes together with advances in synthetic biology has moved metabolic engineering forward, expanding substrate ranges. Here we review the latest advances made using the industrial yeast Yarrowia lipolytica, which can exploit various carbon sources to produce biofuels and chemicals.

  7. Optimization of nicotinamide and riboflavin in the biodesulfurization of dibenzothiophene using response surface methodology

    Directory of Open Access Journals (Sweden)

    Hossein Saber

    2013-01-01

    Full Text Available Introduction: Dibenzothiophene (DBT is a sulfuric compound and resistant to Hydrodesulfurization process.Rhodococcuserythropolis R1, a previously isolated bacterial strain, is capable to bioconversion of DBT to 2-hydroxybiphenyl (2-HBP.Materials and methods: The effect of nicotinamide (precursor of NAD and riboflavin (precursor of FMN on DBT biodesulfurization and growth rate by this strain was studied using Gibbs assay and turbidimeteric assay respectively. The level of cofactor precursors were optimized using response surface methodology (RSM. Results: Analyses showed that both nicotinamide and riboflavin were statistically significant and could enhance the biodesulfurization rate of DBT by induction of dsz operon. The optimum level of nicotinamide and riboflavin was obtained at 10.67 mM and 34.2 µM respectively. Discussion and conclusion: In spite of increasing in BDS, the addition of these cofactor precursors led to decreased growth rate and biomass production due to limitated effect of produced 2-HBP.

  8. The significance of the initiation process parameters and reactor design for maximizing the efficiency of microbial fuel cells

    DEFF Research Database (Denmark)

    Sun, Guotao; Thygesen, Anders; Ale, Marcel Tutor

    2014-01-01

    Microbial fuel cells (MFCs) can be used for electricity generation via bioconversion of wastewater and organic waste substrates. MFCs also hold potential for production of certain chemicals, such as H2 and H2O2. The studies of electricity generation in MFCs have mainly focused on the microbial...... community formation, substrate effect on the anode reaction, and the cathode’s catalytic properties. To improve the performance of MFCs, the initiation process requiresmore investigation because of its significant effect on the anodic biofilm formation. This review explores the factors which affect...... the initiation process, including inoculum, substrate, and reactor configuration. The key messages are that optimal performance of MFCs for electricity production requires (1) understanding of the electrogenic bacterial biofilm formation, (2) proper substrates at the initiation stage, (3) focus on operational...

  9. The significance of the initiation process parameters and reactor design for maximizing the efficiency of microbial fuel cells.

    Science.gov (United States)

    Sun, Guotao; Thygesen, Anders; Ale, Marcel Tutor; Mensah, Moses; Poulsen, Finn Willy; Meyer, Anne S

    2014-03-01

    Microbial fuel cells (MFCs) can be used for electricity generation via bioconversion of wastewater and organic waste substrates. MFCs also hold potential for production of certain chemicals, such as H2 and H2O2. The studies of electricity generation in MFCs have mainly focused on the microbial community formation, substrate effect on the anode reaction, and the cathode's catalytic properties. To improve the performance of MFCs, the initiation process requires more investigation because of its significant effect on the anodic biofilm formation. This review explores the factors which affect the initiation process, including inoculum, substrate, and reactor configuration. The key messages are that optimal performance of MFCs for electricity production requires (1) understanding of the electrogenic bacterial biofilm formation, (2) proper substrates at the initiation stage, (3) focus on operational conditions affecting initial biofilm formation, and (4) attention to the reactor configuration.

  10. 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

    -AD) wasused to accelerate methane production for energy recovery from WAS. Carbon bioconversion wasaccelerated by ME producing H2 at the cathode. MPR was enhanced to 91.8 gCH4/m3 reactor/d in themicrobial electrolysis ME-AD reactor, thus improving the rate by 3 times compared to control conditions (30.6 gCH4......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....../m3 reactor/d in AD). The methane production yield reached 116.2 mg/g VSS in the ME-ADreactor. According to balance calculation on electron transfer and methane yield, the increasedmethane production was mostly dependent on electron contribution through the ME system. Thus, theuse of the novel ME...

  11. Enzymatic routes for the production of mono- and di-glucosylated derivatives of hydroxytyrosol.

    Science.gov (United States)

    Trincone, Antonio; Pagnotta, Eduardo; Tramice, Annabella

    2012-07-01

    In this work, a new eco-friendly procedure for the synthesis of hydroxytyrosol and tyrosol α-glycosidic derivatives was proposed by using the marine α-glucosidase from Aplysia fasciata, and a commercial tyrosinase from mushroom for the bioconversion of tyrosol glycosidic derivatives into the corresponding hydroxytyrosol products. New hydroxytyrosol mono- and di-saccharide derivatives were synthesized at final concentrations of 9.35 and 10.8 g/l of reaction, respectively, and their antioxidant activity was evaluated by DPPH test. The best antioxidant agent resulted the (3,4-dihydroxyphenyl) ethyl-α-D-glucopyranoside; it showed a radical scavenging activity similar to that of the hydroxytyrosol, together with an increased hydrosolubility. This molecule could be a good response to many food industry demands, always in search of cheap antioxidants with nutritional properties to improve the nutritional value and the quality of foods.

  12. Fossil Energy Program annual progress report for April 1996 through March 1997

    Energy Technology Data Exchange (ETDEWEB)

    Judkins, R.R.

    1997-07-01

    The Oak Ridge National Laboratory (ORNL) Fossil Energy Program research and development activities, performed for the Department of Energy (DOE) Assistant Secretary for Fossil Energy, cover the areas of coal, clean coal technology, gas, petroleum, and support to the Strategic Petroleum Reserve. The coal activities include materials research and development; environmental analysis support; bioprocessing of coal to produce liquid or gaseous fuels; and coal combustion research. The work in support of gas technologies includes activities on the Advanced Turbine Systems Program, primarily in the materials and manufacturing aspects. Several activities are contributing to petroleum technologies in the areas of computational tools for seismic analysis and the use of bioconversion for the removal of impurities from heavy oils. This report contains 32 papers describing the various research activities, arranged under the following topical sections: materials research and development; environmental analysis support; bioprocessing research; coal combustion research; fossil fuel supply modeling and research; and advanced turbine systems.

  13. Anaerobic biotransformation of organoarsenical pesticides monomethylarsonic acid and dimethylarsinic acid

    Science.gov (United States)

    Sierra-Alvarez, R.; Yenal, U.; Feld, J.A.; Kopplin, M.; Gandolfi, A.J.; Garbarino, J.R.

    2006-01-01

    Monomethylarsonic acid (MMAV) and dimethylarsinic acid (DMAV) are extensively utilized as pesticides, introducing large quantities of arsenic into the environment. Once released into the environment, these organoarsenicals are subject to microbial reactions. Aerobic biodegradation of MMAV and DMAV has been evaluated, but little is known about their fate in anaerobic environments. The objective of this study was to evaluate the biotransformation of MMAV and DMAV in anaerobic sludge. Biologically mediated conversion occurred under methanogenic or sulfate-reducing conditions but not in the presence of nitrate. Monomethylarsonous acid (MMAIII) was consistently observed as an important metabolite of MMAV degradation, and it was recovered in molar yields ranging from 5 to 47%. The main biotransformation product identified from DMAV metabolism was MMAV, which was recovered in molar yields ranging from 8 to 65%. The metabolites indicate that reduction and demethylation are important steps in the anaerobic bioconversion of MMAV and DMAV, respectively. ?? 2006 American Chemical Society.

  14. Improving the production yield and productivity of 1,3-dihydroxyacetone from glycerol fermentation using Gluconobacter oxydans NL71 in a compressed oxygen supply-sealed and stirred tank reactor (COS-SSTR).

    Science.gov (United States)

    Zhou, Xin; Zhou, Xuelian; Xu, Yong; Yu, Shiyuan

    2016-08-01

    In this study, a compressed oxygen gas supply was connected to a sealed aerated stirred tank reactor (COS-SSTR) bio-system, leading to a high-oxygen pressure bioreactor used to improve the bio-transformative performance in the production of 1,3-dihydroxyacetone (DHA) from glycerol using Gluconobacter oxydans NL71. A concentration of 301.2 ± 8.2 g L(-1) DHA was obtained from glycerol after 32 h of fed-batch fermentation in the COS-SSTR system. The volumetric productivity for this process was 9.41 ± 0.23 g L(-1) h(-1), which is presently the highest obtained level of glycerol bioconversion into DHA. These results show that the application of this bioreactor would enable microbial production of DHA from glycerol at the industrial scale.

  15. Generation of thiols by biotransformation of cysteine-aldehyde conjugates with baker's yeast.

    Science.gov (United States)

    Huynh-Ba, Tuong; Matthey-Doret, Walter; Fay, Laurent B; Bel Rhlid, Rachid

    2003-06-01

    Baker's yeast was shown to catalyze the transformation of cysteine-furfural conjugate into 2-furfurylthiol. The biotransformation's yield and kinetics were influenced by the reaction parameters such as pH, incubation mode (aerobic and anaerobic), and substrate concentration. 2-Furfurylthiol was obtained in an optimal 37% yield when cysteine-furfural conjugate at a 20 mM concentration was anaerobically incubated with whole cell baker's yeast at pH 8.0 and 30 degrees C. Similarly to 2-furfurylthiol, 5-methyl-2-furfurylthiol (11%), benzylthiol (8%), 2-thiophenemethanethiol (22%), 3-methyl-2-thiophenemethanethiol (3%), and 2-pyrrolemethanethiol (6%) were obtained from the corresponding cysteine-aldehyde conjugates by incubation with baker's yeast. This work indicates the versatile bioconversion capacity of baker's yeast for the generation of thiols from cysteine-aldehyde conjugates. Thanks to its food-grade character, baker's yeast provides a biochemical tool to produce thiols, which can be used as flavorings in foods and beverages.

  16. Improved release and metabolism of flavonoids by steered fermentation processes: a review.

    Science.gov (United States)

    Huynh, Nguyen Thai; Van Camp, John; Smagghe, Guy; Raes, Katleen

    2014-10-24

    This paper provides an overview on steered fermentation processes to release phenolic compounds from plant-based matrices, as well as on their potential application to convert phenolic compounds into unique metabolites. The ability of fermentation to improve the yield and to change the profile of phenolic compounds is mainly due to the release of bound phenolic compounds, as a consequence of the degradation of the cell wall structure by microbial enzymes produced during fermentation. Moreover, the microbial metabolism of phenolic compounds results in a large array of new metabolites through different bioconversion pathways such as glycosylation, deglycosylation, ring cleavage, methylation, glucuronidation and sulfate conjugation, depending on the microbial strains and substrates used. A whole range of metabolites is produced, however metabolic pathways related to the formation and bioactivities, and often quantification of the metabolites are highly underinvestigated. This strategy could have potential to produce extracts with a high-added value from plant-based matrices.

  17. Ammonia inhibition on hydrogen enriched anaerobic digestion of manure under mesophilic and thermophilic conditions

    DEFF Research Database (Denmark)

    Wang, Han; Zhang, Yifeng; Angelidaki, Irini

    2016-01-01

    methanogens in the hydrogen enriched biogas production and upgrading processes. The highest methane production yield was achieved under 0.5 atm hydrogen partial pressure in batch reactors at all the tested ammonia levels. Furthermore, the thermophilic methanogens at 0.5 atm of hydrogen partial pressure were......Capturing of carbon dioxide by hydrogen derived from excess renewable energy (e.g., wind mills) to methane in a microbially catalyzed process offers an attractive technology for biogas production and upgrading. This bioconversion process is catalyzed by hydrogenotrophic methanogens, which are known...... more tolerant to high ammonia levels (≥5 g NH4+-N L−1), compared with mesophilic methanogens. The present study offers insight in developing resistant hydrogen enriched biogas production and upgrading processes treating ammonia-rich waste streams....

  18. Energy from solid waste: recent developments

    Energy Technology Data Exchange (ETDEWEB)

    Domino, F.A. (ed.)

    1979-01-01

    Presently available waste processing technologies and technologies under current development for energy recovery from municipal solid wastes are described. The applicability of the technologies, technical difficulties and problems, and potential are considered. In addition to a tabulation of the sources used as basic references, each chapter has supplementary references. The topic discussed are: an overview of energy recovery tecnologies, Nashville Thermal Transfer Corporation Plant, St. Louis Demonstration Plant, CPU-400 pilot plant, Coluumbia plan for New York City, technical evaluation of pyrolysis systems, fuel and energy from waste materials by bioconversion, environmental aspects, and municipal-scale thermal processing of solid wastes. The book can be used by municipal and state officials in initial planning of waste processing with energy recovery. (JSR)

  19. Comparative biochemical analysis after steam pretreatment of lignocellulosic agricultural waste biomass from Williams Cavendish banana plant (Triploid Musa AAA group).

    Science.gov (United States)

    Kamdem, Irénée; Jacquet, Nicolas; Tiappi, Florian Mathias; Hiligsmann, Serge; Vanderghem, Caroline; Richel, Aurore; Jacques, Philippe; Thonart, Philippe

    2015-11-01

    The accessibility of fermentable substrates to enzymes is a limiting factor for the efficient bioconversion of agricultural wastes in the context of sustainable development. This paper presents the results of a biochemical analysis performed on six combined morphological parts of Williams Cavendish Lignocellulosic Biomass (WCLB) after steam cracking (SC) and steam explosion (SE) pretreatments. Solid (S) and liquid (L) fractions (Fs) obtained from SC pretreatment performed at 180°C (SLFSC180) and 210°C (SLFSC210) generated, after diluted acid hydrolysis, the highest proportions of neutral sugar (NS) contents, specifically 52.82 ± 3.51 and 49.78 ± 1.39%w/w WCLB dry matter (DM), respectively. The highest proportions of glucose were found in SFSC210 (53.56 ± 1.33%w/w DM) and SFSC180 (44.47 ± 0.00%w/w DM), while the lowest was found in unpretreated WCLB (22.70 ± 0.71%w/w DM). Total NS content assessed in each LF immediately after SC and SE pretreatments was less than 2%w/w of the LF DM, thus revealing minor acid autohydrolysis consequently leading to minor NS production during the steam pretreatment. WCLB subjected to SC at 210 °C (SC210) generated up to 2.7-fold bioaccessible glucan and xylan. SC and SE pretreatments showed potential for the deconstruction of WCLB (delignification, depolymerization, decrystallization and deacetylation), enhancing its enzymatic hydrolysis. The concentrations of enzymatic inhibitors, such as 2-furfuraldehyde and 5-(hydroxymethyl)furfural from LFSC210, were the highest (41 and 21 µg ml(-1), respectively). This study shows that steam pretreatments in general and SC210 in particular are required for efficient bioconversion of WCLB. Yet, biotransformation through biochemical processes (e.g., anaerobic digestion) must be performed to assess the efficiency of these pretreatments.

  20. Fermentation of lignocellulosic sugars to acetic acid by Moorella thermoacetica.

    Science.gov (United States)

    Ehsanipour, Mandana; Suko, Azra Vajzovic; Bura, Renata

    2016-06-01

    A systematic study of bioconversion of lignocellulosic sugars to acetic acid by Moorella thermoacetica (strain ATCC 39073) was conducted. Four different water-soluble fractions (hydrolysates) obtained after steam pretreatment of lignocellulosic biomass were selected and fermented to acetic acid in batch fermentations. M. thermoacetica can effectively ferment xylose and glucose in hydrolysates from wheat straw, forest residues, switchgrass, and sugarcane straw to acetic acid. Xylose and glucose were completely utilized, with xylose being consumed first. M. thermoacetica consumed up to 62 % of arabinose, 49 % galactose and 66 % of mannose within 72 h of fermentation in the mixture of lignocellulosic sugars. The highest acetic acid yield was obtained from sugarcane straw hydrolysate, with 71 % of theoretical yield based on total sugars (17 g/L acetic acid from 24 g/L total sugars). The lowest acetic acid yield was observed in forest residues hydrolysate, with 39 % of theoretical yield based on total sugars (18 g/L acetic acid from 49 g/L total sugars). Process derived compounds from steam explosion pretreatment, including 5-hydroxymethylfurfural (0.4 g/L), furfural (0.1 g/L) and total phenolics (3 g/L), did not inhibit microbial growth and acetic acid production yield. This research identified two major factors that adversely affected acetic acid yield in all hydrolysates, especially in forest residues: (i) glucose to xylose ratio and (ii) incomplete consumption of arabinose, galactose and mannose. For efficient bioconversion of lignocellulosic sugars to acetic acid, it is imperative to have an appropriate balance of sugars in a hydrolysate. Hence, the choice of lignocellulosic biomass and steam pretreatment design are fundamental steps for the industrial application of this process.