Bacterial microcompartments as metabolic modules for plant synthetic biology.

Science.gov (United States)

Gonzalez-Esquer, C Raul; Newnham, Sarah E; Kerfeld, Cheryl A

2016-07-01

Bacterial microcompartments (BMCs) are megadalton-sized protein assemblies that enclose segments of metabolic pathways within cells. They increase the catalytic efficiency of the encapsulated enzymes while sequestering volatile or toxic intermediates from the bulk cytosol. The first BMCs discovered were the carboxysomes of cyanobacteria. Carboxysomes compartmentalize the enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) with carbonic anhydrase. They enhance the carboxylase activity of RuBisCO by increasing the local concentration of CO2 in the vicinity of the enzyme's active site. As a metabolic module for carbon fixation, carboxysomes could be transferred to eukaryotic organisms (e.g. plants) to increase photosynthetic efficiency. Within the scope of synthetic biology, carboxysomes and other BMCs hold even greater potential when considered a source of building blocks for the development of nanoreactors or three-dimensional scaffolds to increase the efficiency of either native or heterologously expressed enzymes. The carboxysome serves as an ideal model system for testing approaches to engineering BMCs because their expression in cyanobacteria provides a sensitive screen for form (appearance of polyhedral bodies) and function (ability to grow on air). We recount recent progress in the re-engineering of the carboxysome shell and core to offer a conceptual framework for the development of BMC-based architectures for applications in plant synthetic biology. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

Comparison of alternate fuels for aircraft. [liquid hydrogen, liquid methane, and synthetic aviation kerosene

Science.gov (United States)

Witcofski, R. D.

1979-01-01

Liquid hydrogen, liquid methane, and synthetic aviation kerosene were assessed as alternate fuels for aircraft in terms of cost, capital requirements, and energy resource utilization. Fuel transmission and airport storage and distribution facilities are considered. Environmental emissions and safety aspects of fuel selection are discussed and detailed descriptions of various fuel production and liquefaction processes are given. Technological deficiencies are identified.

Metabolic Engineering for Production of Biorenewable Fuels and Chemicals: Contributions of Synthetic Biology

Directory of Open Access Journals (Sweden)

Laura R. Jarboe

2010-01-01

Full Text Available Production of fuels and chemicals through microbial fermentation of plant material is a desirable alternative to petrochemical-based production. Fermentative production of biorenewable fuels and chemicals requires the engineering of biocatalysts that can quickly and efficiently convert sugars to target products at a cost that is competitive with existing petrochemical-based processes. It is also important that biocatalysts be robust to extreme fermentation conditions, biomass-derived inhibitors, and their target products. Traditional metabolic engineering has made great advances in this area, but synthetic biology has contributed and will continue to contribute to this field, particularly with next-generation biofuels. This work reviews the use of metabolic engineering and synthetic biology in biocatalyst engineering for biorenewable fuels and chemicals production, such as ethanol, butanol, acetate, lactate, succinate, alanine, and xylitol. We also examine the existing challenges in this area and discuss strategies for improving biocatalyst tolerance to chemical inhibitors.

Effectiveness of hydrogen rich water on antioxidant status of subjects with potential metabolic syndrome-an open label pilot study.

Science.gov (United States)

Nakao, Atsunori; Toyoda, Yoshiya; Sharma, Prachi; Evans, Malkanthi; Guthrie, Najla

2010-03-01

Metabolic syndrome is characterized by cardiometabolic risk factors that include obesity, insulin resistance, hypertension and dyslipidemia. Oxidative stress is known to play a major role in the pathogenesis of metabolic syndrome. The objective of this study was to examine the effectiveness of hydrogen rich water (1.5-2 L/day) in an open label, 8-week study on 20 subjects with potential metabolic syndrome. Hydrogen rich water was produced, by placing a metallic magnesium stick into drinking water (hydrogen concentration; 0.55-0.65 mM), by the following chemical reaction; Mg + 2H(2)O --> Mg (OH)(2) + H(2). The consumption of hydrogen rich water for 8 weeks resulted in a 39% increase (pfasting glucose levels during the 8 week study. In conclusion, drinking hydrogen rich water represents a potentially novel therapeutic and preventive strategy for metabolic syndrome. The portable magnesium stick was a safe, easy and effective method of delivering hydrogen rich water for daily consumption by participants in the study.

Study on substrate metabolism process of saline waste sludge and its biological hydrogen production potential.

Science.gov (United States)

Zhang, Zengshuai; Guo, Liang; Li, Qianqian; Zhao, Yangguo; Gao, Mengchun; She, Zonglian

2017-07-01

With the increasing of high saline waste sludge production, the treatment and utilization of saline waste sludge attracted more and more attention. In this study, the biological hydrogen production from saline waste sludge after heating pretreatment was studied. The substrate metabolism process at different salinity condition was analyzed by the changes of soluble chemical oxygen demand (SCOD), carbohydrate and protein in extracellular polymeric substances (EPS), and dissolved organic matters (DOM). The excitation-emission matrix (EEM) with fluorescence regional integration (FRI) was also used to investigate the effect of salinity on EPS and DOM composition during hydrogen fermentation. The highest hydrogen yield of 23.6 mL H 2 /g VSS and hydrogen content of 77.6% were obtained at 0.0% salinity condition. The salinity could influence the hydrogen production and substrate metabolism of waste sludge.

Metabolism and toxicological analysis of synthetic cannabinoids in biological fluids and tissues.

Science.gov (United States)

Presley, B C; Gurney, S M R; Scott, K S; Kacinko, S L; Logan, B K

2016-07-01

Synthetic cannabinoids, which began proliferating in the United States in 2009, have gone through numerous iterations of modification to their chemical structures. More recent generations of compounds have been associated with significant adverse outcomes following use, including cognitive and psychomotor impairment, seizures, psychosis, tissue injury and death. These effects increase the urgency for forensic and public health laboratories to develop methods for the detection and identification of novel substances, and apply these to the determination of their metabolism and disposition in biological samples. This comprehensive review describes the history of the appearance of the drugs in the United States, discusses the naming conventions emerging to designate new structures, and describes the most prominent new compounds linked to the adverse effects now associated with their use. We review in depth the metabolic pathways that have been elucidated for the major members of each of the prevalent synthetic cannabinoid drug subclasses, the enzyme systems responsible for their metabolism, and the use of in silico approaches to assist in predicting and identifying the metabolites of novel compounds and drug subclasses that will continue to appear. Finally, we review and critique analytical methods applied to the detection of the drugs and their metabolites, including immunoassay screening, and liquid chromatography mass spectrometry confirmatory techniques applied to urine, serum, whole blood, oral fluid, hair, and tissues. Copyright © 2016 Central Police University.

(Carbon and hydrogen metabolism of green algae in light and dark)

Energy Technology Data Exchange (ETDEWEB)

1990-01-01

The focus of this project was the elucidation of anaerobic metabolism in ecuaryotic green algae, chlamydomonas reinhardii. Chlamydomonas is a versatile organism that can grow under disparate conditions such as fresh water lakes and sewage ponds. The cell an photoassimilate CO{sub 2} aerobically and anaerobically, the latter after adaptation'' to a hydrogen metabolism. It can recall the knallgas or oxyhydrogen reaction and utilize hydrogen the simplest of all reducing agents for the dark assimilation of CO{sub 2} by the photosynthetic carbon reduction cycle. The dark reduction with hydrogen lies on the border line between autotrophic and heterotrophic carbon assimilation. Both autotrophic and heterotrophic bacteria are known in which molecular hydrogen can replace either inorganic or organic hydrogen donors. Here the dark reduction of CO{sub 2} acquires a particular importance since it occurs in the same cell that carries on photoreduction and photosynthesis. We will demonstrate here that the alga chloroplast possesses a respiratory capacity. It seems likely that Chlamydomonas may have retained the chloroplastic respiratory pathway because of the selective advantage provided to the algae under a wide range of environmental conditions that the cells experience in nature. The ability to cycle electrons and poise the reduction level of the photosynthetic apparatus under aerobic and microaerobic conditions could allow more efficient CO{sub 2} fixation and enhanced growth under unfavorable conditions or survival under more severe conditions.

Towards a sustainable bio-based economy: Redirecting primary metabolism to new products with plant synthetic biology.

Science.gov (United States)

Shih, Patrick M

2018-08-01

Humans have domesticated many plant species as indispensable sources of food, materials, and medicines. The dawning era of synthetic biology represents a means to further refine, redesign, and engineer crops to meet various societal and industrial needs. Current and future endeavors will utilize plants as the foundation of a bio-based economy through the photosynthetic production of carbohydrate feedstocks for the microbial fermentation of biofuels and bioproducts, with the end goal of decreasing our dependence on petrochemicals. As our technological capabilities improve, metabolic engineering efforts may expand the utility of plants beyond sugar feedstocks through the direct production of target compounds, including pharmaceuticals, renewable fuels, and commodity chemicals. However, relatively little work has been done to fully realize the potential in redirecting central carbon metabolism in plants for the engineering of novel bioproducts. Although our ability to rationally engineer and manipulate plant metabolism is in its infancy, I highlight some of the opportunities and challenges in applying synthetic biology towards engineering plant primary metabolism. Copyright © 2018 Elsevier B.V. All rights reserved.

FindPath: a Matlab solution for in silico design of synthetic metabolic pathways.

Science.gov (United States)

Vieira, Gilles; Carnicer, Marc; Portais, Jean-Charles; Heux, Stéphanie

2014-10-15

Several methods and computational tools have been developed to design novel metabolic pathways. A major challenge is evaluating the metabolic efficiency of the designed pathways in the host organism. Here we present FindPath, a unified system to predict and rank possible pathways according to their metabolic efficiency in the cellular system. This tool uses a chemical reaction database to generate possible metabolic pathways and exploits constraint-based models (CBMs) to identify the most efficient synthetic pathway to achieve the desired metabolic function in a given host microorganism. FindPath can be used with common tools for CBM manipulation and uses the standard SBML format for both input and output files. http://metasys.insa-toulouse.fr/software/findpath/. heux@insa-toulouse.fr Supplementary data are available at Bioinformatics online. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

CYP3A4 Mediates Oxidative Metabolism of the Synthetic Cannabinoid AKB-48.

Science.gov (United States)

Holm, Niels Bjerre; Nielsen, Line Marie; Linnet, Kristian

2015-09-01

Synthetic cannabinoid designer drugs have emerged as drugs of abuse during the last decade, and acute intoxication cases are documented in the scientific literature. Synthetic cannabinoids are extensively metabolized, but our knowledge of the involved enzymes is limited. Here, we investigated the metabolism of N-(1-adamantyl)-1-pentyl-1H-indazole-3-carboxamide (AKB-48), a compound identified in herbal blends from 2012 and onwards. We screened for metabolite formation using a panel of nine recombinant cytochrome P450 (CYP) enzymes (CYP1A2, 2B6, 2C8, 2C9, 2C18, 2C19, 2D6, 2E1, and 3A4) and compared the formed metabolites to human liver microsomal (HLM) incubations with specific inhibitors against CYP2D6, 2C19, and 3A4, respectively. The data reported here demonstrate CYP3A4 to be the major CYP enzyme responsible for the oxidative metabolism of AKB-48, preferentially performing the oxidation on the adamantyl moiety. Genetic polymorphisms are likely not important with regard to toxicity given the major involvement of CYP3A4. Adverse drug-drug interactions (DDIs) could potentially occur in cases with co-intake of strong CYP3A4 inhibitors, e.g., HIV antivirals and azole antifungal agents.

Hydrogen production and metabolic flux analysis of metabolically engineered Escherichia coli strains

Energy Technology Data Exchange (ETDEWEB)

Kim, Seohyoung; Seol, Eunhee; Park, Sunghoon [Department of Chemical and Biochemical Engineering, Pusan National University, Busan 609-735 (Korea); Oh, You-Kwan [Bioenergy Research Center, Korea Institute of Energy Research, Daejeon 305-543 (Korea); Wang, G.Y. [Department of Oceanography, University of Hawaii at Manoa Honolulu, HI 96822 (United States)

2009-09-15

Escherichia coli can produce H{sub 2} from glucose via formate hydrogen lyase (FHL). In order to improve the H{sub 2} production rate and yield, metabolically engineered E. coli strains, which included pathway alterations in their H{sub 2} production and central carbon metabolism, were developed and characterized by batch experiments and metabolic flux analysis. Deletion of hycA, a negative regulator for FHL, resulted in twofold increase of FHL activity. Deletion of two uptake hydrogenases (1 (hya) and hydrogenase 2 (hyb)) increased H{sub 2} production yield from 1.20 mol/mol glucose to 1.48 mol/mol glucose. Deletion of lactate dehydrogenase (ldhA) and fumarate reductase (frdAB) further improved the H{sub 2} yield; 1.80 mol/mol glucose under high H{sub 2} pressure or 2.11 mol/mol glucose under reduced H{sub 2} pressure. Several batch experiments at varying concentrations of glucose (2.5-10 g/L) and yeast extract (0.3 or 3.0 g/L) were conducted for the strain containing all these genetic alternations, and their carbon and energy balances were analyzed. The metabolic flux analysis revealed that deletion of ldhA and frdAB directed most of the carbons from glucose to the glycolytic pathway leading to H{sub 2} production by FHL, not to the pentose phosphate pathway. (author)

The Future of Metabolic Engineering and Synthetic Biology: Towards a Systematic Practice

Science.gov (United States)

Yadav, Vikramaditya G.; De Mey, Marjan; Lim, Chin Giaw; Ajikumar, Parayil Kumaran; Stephanopoulos, Gregory

2012-01-01

Industrial biotechnology promises to revolutionize conventional chemical manufacturing in the years ahead, largely owing to the excellent progress in our ability to re-engineer cellular metabolism. However, most successes of metabolic engineering have been confined to over-producing natively synthesized metabolites in E. coli and S. cerevisiae. A major reason for this development has been the descent of metabolic engineering, particularly secondary metabolic engineering, to a collection of demonstrations rather than a systematic practice with generalizable tools. Synthetic biology, a more recent development, faces similar criticisms. Herein, we attempt to lay down a framework around which bioreaction engineering can systematize itself just like chemical reaction engineering. Central to this undertaking is a new approach to engineering secondary metabolism known as ‘multivariate modular metabolic engineering’ (MMME), whose novelty lies in its assessment and elimination of regulatory and pathway bottlenecks by re-defining the metabolic network as a collection of distinct modules. After introducing the core principles of MMME, we shall then present a number of recent developments in secondary metabolic engineering that could potentially serve as its facilitators. It is hoped that the ever-declining costs of de novo gene synthesis; the improved use of bioinformatic tools to mine, sort and analyze biological data; and the increasing sensitivity and sophistication of investigational tools will make the maturation of microbial metabolic engineering an autocatalytic process. Encouraged by these advances, research groups across the world would take up the challenge of secondary metabolite production in simple hosts with renewed vigor, thereby adding to the range of products synthesized using metabolic engineering. PMID:22629571

Degradation and metabolism of synthetic plastics and associated products by Pseudomonas sp.: capabilities and challenges.

Science.gov (United States)

Wilkes, R A; Aristilde, L

2017-09-01

Synthetic plastics, which are widely present in materials of everyday use, are ubiquitous and slowly-degrading polymers in environmental wastes. Of special interest are the capabilities of microorganisms to accelerate their degradation. Members of the metabolically diverse genus Pseudomonas are of particular interest due to their capabilities to degrade and metabolize synthetic plastics. Pseudomonas species isolated from environmental matrices have been identified to degrade polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyurethane, polyethylene terephthalate, polyethylene succinate, polyethylene glycol and polyvinyl alcohol at varying degrees of efficiency. Here, we present a review of the current knowledge on the factors that control the ability of Pseudomonas sp. to process these different plastic polymers and their by-products. These factors include cell surface attachment within biofilms, catalytic enzymes involved in oxidation or hydrolysis of the plastic polymer, metabolic pathways responsible for uptake and assimilation of plastic fragments and chemical factors that are advantageous or inhibitory to the biodegradation process. We also highlight future research directions required in order to harness fully the capabilities of Pseudomonas sp. in bioremediation strategies towards eliminating plastic wastes. © 2017 The Society for Applied Microbiology.

The future of metabolic engineering and synthetic biology: towards a systematic practice.

Science.gov (United States)

Yadav, Vikramaditya G; De Mey, Marjan; Lim, Chin Giaw; Ajikumar, Parayil Kumaran; Stephanopoulos, Gregory

2012-05-01

Industrial biotechnology promises to revolutionize conventional chemical manufacturing in the years ahead, largely owing to the excellent progress in our ability to re-engineer cellular metabolism. However, most successes of metabolic engineering have been confined to over-producing natively synthesized metabolites in E. coli and S. cerevisiae. A major reason for this development has been the descent of metabolic engineering, particularly secondary metabolic engineering, to a collection of demonstrations rather than a systematic practice with generalizable tools. Synthetic biology, a more recent development, faces similar criticisms. Herein, we attempt to lay down a framework around which bioreaction engineering can systematize itself just like chemical reaction engineering. Central to this undertaking is a new approach to engineering secondary metabolism known as 'multivariate modular metabolic engineering' (MMME), whose novelty lies in its assessment and elimination of regulatory and pathway bottlenecks by re-defining the metabolic network as a collection of distinct modules. After introducing the core principles of MMME, we shall then present a number of recent developments in secondary metabolic engineering that could potentially serve as its facilitators. It is hoped that the ever-declining costs of de novo gene synthesis; the improved use of bioinformatic tools to mine, sort and analyze biological data; and the increasing sensitivity and sophistication of investigational tools will make the maturation of microbial metabolic engineering an autocatalytic process. Encouraged by these advances, research groups across the world would take up the challenge of secondary metabolite production in simple hosts with renewed vigor, thereby adding to the range of products synthesized using metabolic engineering. Copyright © 2011 Elsevier Inc. All rights reserved.

Cell Wall Remodeling by a Synthetic Analog Reveals Metabolic Adaptation in Vancomycin Resistant Enterococci.

Science.gov (United States)

Pidgeon, Sean E; Pires, Marcos M

2017-07-21

Drug-resistant bacterial infections threaten to overburden our healthcare system and disrupt modern medicine. A large class of potent antibiotics, including vancomycin, operate by interfering with bacterial cell wall biosynthesis. Vancomycin-resistant enterococci (VRE) evade the blockage of cell wall biosynthesis by altering cell wall precursors, rendering them drug insensitive. Herein, we reveal the phenotypic plasticity and cell wall remodeling of VRE in response to vancomycin in live bacterial cells via a metabolic probe. A synthetic cell wall analog was designed and constructed to monitor cell wall structural alterations. Our results demonstrate that the biosynthetic pathway for vancomycin-resistant precursors can be hijacked by synthetic analogs to track the kinetics of phenotype induction. In addition, we leveraged this probe to interrogate the response of VRE cells to vancomycin analogs and a series of cell wall-targeted antibiotics. Finally, we describe a proof-of-principle strategy to visually inspect drug resistance induction. Based on our findings, we anticipate that our metabolic probe will play an important role in further elucidating the interplay among the enzymes involved in the VRE biosynthetic rewiring.

Synthetic Biology and Metabolic Engineering Approaches and Its Impact on Non-Conventional Yeast and Biofuel Production

Energy Technology Data Exchange (ETDEWEB)

Madhavan, Aravind [Biotechnology Division, National Institute for Interdisciplinary Science and Technology, Council of Scientific and Industrial Research, Trivandrum (India); Rajiv Gandhi Centre for Biotechnology, Trivandrum (India); Jose, Anju Alphonsa; Binod, Parameswaran; Sindhu, Raveendran, E-mail: sindhurgcb@gmail.com; Sukumaran, Rajeev K. [Biotechnology Division, National Institute for Interdisciplinary Science and Technology, Council of Scientific and Industrial Research, Trivandrum (India); Pandey, Ashok [Biotechnology Division, National Institute for Interdisciplinary Science and Technology, Council of Scientific and Industrial Research, Trivandrum (India); Center for Innovative and Applied Bioprocessing, Mohali, Punjab (India); Castro, Galliano Eulogio [Dpt. Ingeniería Química, Ambiental y de los Materiales Edificio, Universidad de Jaén, Jaén (Spain)

2017-04-25

The increasing fossil fuel scarcity has led to an urgent need to develop alternative fuels. Currently microorganisms have been extensively used for the production of first-generation biofuels from lignocellulosic biomass. Yeast is the efficient producer of bioethanol among all existing biofuels option. Tools of synthetic biology have revolutionized the field of microbial cell factories especially in the case of ethanol and fatty acid production. Most of the synthetic biology tools have been developed for the industrial workhorse Saccharomyces cerevisiae. The non-conventional yeast systems have several beneficial traits like ethanol tolerance, thermotolerance, inhibitor tolerance, genetic diversity, etc., and synthetic biology have the power to expand these traits. Currently, synthetic biology is slowly widening to the non-conventional yeasts like Hansenula polymorpha, Kluyveromyces lactis, Pichia pastoris, and Yarrowia lipolytica. Herein, we review the basic synthetic biology tools that can apply to non-conventional yeasts. Furthermore, we discuss the recent advances employed to develop efficient biofuel-producing non-conventional yeast strains by metabolic engineering and synthetic biology with recent examples. Looking forward, future synthetic engineering tools’ development and application should focus on unexplored non-conventional yeast species.

Synthetic Biology and Metabolic Engineering Approaches and Its Impact on Non-Conventional Yeast and Biofuel Production

Directory of Open Access Journals (Sweden)

Raveendran Sindhu

2017-04-01

Full Text Available The increasing fossil fuel scarcity has led to an urgent need to develop alternative fuels. Currently microorganisms have been extensively used for the production of first-generation biofuels from lignocellulosic biomass. Yeast is the efficient producer of bioethanol among all existing biofuels option. Tools of synthetic biology have revolutionized the field of microbial cell factories especially in the case of ethanol and fatty acid production. Most of the synthetic biology tools have been developed for the industrial workhorse Saccharomyces cerevisiae. The non-conventional yeast systems have several beneficial traits like ethanol tolerance, thermotolerance, inhibitor tolerance, genetic diversity, etc., and synthetic biology have the power to expand these traits. Currently, synthetic biology is slowly widening to the non-conventional yeasts like Hansenula polymorpha, Kluyveromyces lactis, Pichia pastoris, and Yarrowia lipolytica. Herein, we review the basic synthetic biology tools that can apply to non-conventional yeasts. Furthermore, we discuss the recent advances employed to develop efficient biofuel-producing non-conventional yeast strains by metabolic engineering and synthetic biology with recent examples. Looking forward, future synthetic engineering tools’ development and application should focus on unexplored non-conventional yeast species.

Synthetic Biology and Metabolic Engineering Approaches and Its Impact on Non-Conventional Yeast and Biofuel Production

International Nuclear Information System (INIS)

Madhavan, Aravind; Jose, Anju Alphonsa; Binod, Parameswaran; Sindhu, Raveendran; Sukumaran, Rajeev K.; Pandey, Ashok; Castro, Galliano Eulogio

2017-01-01

The increasing fossil fuel scarcity has led to an urgent need to develop alternative fuels. Currently microorganisms have been extensively used for the production of first-generation biofuels from lignocellulosic biomass. Yeast is the efficient producer of bioethanol among all existing biofuels option. Tools of synthetic biology have revolutionized the field of microbial cell factories especially in the case of ethanol and fatty acid production. Most of the synthetic biology tools have been developed for the industrial workhorse Saccharomyces cerevisiae. The non-conventional yeast systems have several beneficial traits like ethanol tolerance, thermotolerance, inhibitor tolerance, genetic diversity, etc., and synthetic biology have the power to expand these traits. Currently, synthetic biology is slowly widening to the non-conventional yeasts like Hansenula polymorpha, Kluyveromyces lactis, Pichia pastoris, and Yarrowia lipolytica. Herein, we review the basic synthetic biology tools that can apply to non-conventional yeasts. Furthermore, we discuss the recent advances employed to develop efficient biofuel-producing non-conventional yeast strains by metabolic engineering and synthetic biology with recent examples. Looking forward, future synthetic engineering tools’ development and application should focus on unexplored non-conventional yeast species.

Comparison of two anaerobic systems for hydrogen production from the organic fraction of municipal solid waste and synthetic wastewater

Energy Technology Data Exchange (ETDEWEB)

Alzate-Gaviria, Liliana M. [Centro de Investigacion en Energia-UNAM, 62580 Temixco, Morelos (Mexico); Sebastian, P.J. [Centro de Investigacion en Energia-UNAM, 62580 Temixco, Morelos (Mexico); Universidad Politecnica de Chiapas, 29010 Tuxtla Gutierrez, Chiapas (Mexico); Perez-Hernandez, Antonino [Centro de Investigacion en Materiales Avanzados, Miguel de Cervantes 120, Complejo Industrial Chihuahua, Chihuahua 31109 (Mexico); Eapen, D. [Universidad Politecnica de Chiapas, 29010 Tuxtla Gutierrez, Chiapas (Mexico)

2007-10-15

Two laboratory scale anaerobic digestion systems for hydrogen production from organic fraction of municipal solid waste (OFMSW) and synthetic wastewater were compared in this study. One of them was formed by a coupled packed bed reactor (PBR) containing 19.4 L of OFMSW and the other an upflow anaerobic sludge bed (UASB) of 3.85 L. The reactors were inoculated with a mixture of non-anaerobic inocula. In the UASB the percentage of hydrogen yield reached 51% v/v and 127NmLH{sub 2}/gvs removed with a hydraulic retention time (HRT) of 24 h. The concentration of synthetic wastewater in the affluent was 7 g COD/L. For the PBR the percentage yield was 47% v/v and 99NmLH{sub 2}/gvs removed with a mass retention time (MRT) of 50 days and the organic load rate of 16 gvs (Grams Volatile Solids)/(kg-day). The UASB and PBR systems presented maximum hydrogen yields of 30% and 23%, respectively, which correspond to 4molH{sub 2}/mol glucose. These values are similar to those reported in the literature for the hydrogen yield (37%) in mesophilic range. The acetic and butyric acids were present in the effluent as by-products in watery phase. In this work we used non-anaerobic inocula made up of microorganism consortium unlike other works where pure inocula or that from anaerobic sludge was used. (author)

Major Effect of Hydrogen Peroxide on Bacterioplankton Metabolism in the Northeast Atlantic

NARCIS (Netherlands)

Baltar, F.; Reinthaler, T.; Herndl, G.J.; Pinhassi, J.

2013-01-01

Reactive oxygen species such as hydrogen peroxide have the potential to alter metabolic rates of marine prokaryotes, ultimately impacting the cycling and bioavailability of nutrients and carbon. We studied the influence of H2O2 on prokaryotic heterotrophic production (PHP) and extracellular

Impact of synthetic biology and metabolic engineering on industrial production of fine chemicals

DEFF Research Database (Denmark)

Jullesson, David; David, Florian; Pfleger, Brian

2015-01-01

Industrial bio-processes for fine chemical production are increasingly relying on cell factories developed through metabolic engineering and synthetic biology. The use of high throughput techniques and automation for the design of cell factories, and especially platform strains, has played...... chemicals that have reached the market, key metabolic engineering tools that have allowed this to happen and some of the companies that are currently utilizing these technologies for developing industrial production processes....... an important role in the transition from laboratory research to industrial production. Model organisms such as Saccharomyces cerevisiae and Escherichia coli remain widely used host strains for industrial production due to their robust and desirable traits. This review describes some of the bio-based fine...

Impact of metabolism and growth phase on the hydrogen isotopic composition of microbial fatty acids

Science.gov (United States)

Heinzelmann, Sandra M.; Villanueva, Laura; Sinke-Schoen, Danielle; Sinninghe Damsté, Jaap S.; Schouten, Stefan; van der Meer, Marcel T. J.

2015-01-01

Microorganisms are involved in all elemental cycles and therefore it is important to study their metabolism in the natural environment. A recent technique to investigate this is the hydrogen isotopic composition of microbial fatty acids, i.e., heterotrophic microorganisms produce fatty acids enriched in deuterium (D) while photoautotrophic and chemoautotrophic microorganisms produce fatty acids depleted in D compared to the water in the culture medium (growth water). However, the impact of factors other than metabolism have not been investigated. Here, we evaluate the impact of growth phase compared to metabolism on the hydrogen isotopic composition of fatty acids of different environmentally relevant microorganisms with heterotrophic, photoautotrophic and chemoautotrophic metabolisms. Fatty acids produced by heterotrophs are enriched in D compared to growth water with εlipid/water between 82 and 359‰ when grown on glucose or acetate, respectively. Photoautotrophs (εlipid/water between −149 and −264‰) and chemoautotrophs (εlipid/water between −217 and −275‰) produce fatty acids depleted in D. Fatty acids become, in general, enriched by between 4 and 46‰ with growth phase which is minor compared to the influence of metabolisms. Therefore, the D/H ratio of fatty acids is a promising tool to investigate community metabolisms in nature. PMID:26005437

Synthetic biology and regulatory networks: where metabolic systems biology meets control engineering.

Science.gov (United States)

He, Fei; Murabito, Ettore; Westerhoff, Hans V

2016-04-01

Metabolic pathways can be engineered to maximize the synthesis of various products of interest. With the advent of computational systems biology, this endeavour is usually carried out through in silico theoretical studies with the aim to guide and complement further in vitro and in vivo experimental efforts. Clearly, what counts is the result in vivo, not only in terms of maximal productivity but also robustness against environmental perturbations. Engineering an organism towards an increased production flux, however, often compromises that robustness. In this contribution, we review and investigate how various analytical approaches used in metabolic engineering and synthetic biology are related to concepts developed by systems and control engineering. While trade-offs between production optimality and cellular robustness have already been studied diagnostically and statically, the dynamics also matter. Integration of the dynamic design aspects of control engineering with the more diagnostic aspects of metabolic, hierarchical control and regulation analysis is leading to the new, conceptual and operational framework required for the design of robust and productive dynamic pathways. © 2016 The Author(s).

Impact of synthetic biology and metabolic engineering on industrial production of fine chemicals.

Science.gov (United States)

Jullesson, David; David, Florian; Pfleger, Brian; Nielsen, Jens

2015-11-15

Industrial bio-processes for fine chemical production are increasingly relying on cell factories developed through metabolic engineering and synthetic biology. The use of high throughput techniques and automation for the design of cell factories, and especially platform strains, has played an important role in the transition from laboratory research to industrial production. Model organisms such as Saccharomyces cerevisiae and Escherichia coli remain widely used host strains for industrial production due to their robust and desirable traits. This review describes some of the bio-based fine chemicals that have reached the market, key metabolic engineering tools that have allowed this to happen and some of the companies that are currently utilizing these technologies for developing industrial production processes. Copyright © 2015 Elsevier Inc. All rights reserved.

Metabolic flux analysis of the hydrogen production potential in Synechocystis sp. PCC6803

Energy Technology Data Exchange (ETDEWEB)

Navarro, E. [Departamento de Lenguajes y Ciencias de la Computacion, Campus de Teatrinos, Universidad de Malaga, 29071 Malaga (Spain); Montagud, A.; Fernandez de Cordoba, P.; Urchueguia, J.F. [Instituto Universitario de Matematica Pura y Aplicada, Universidad Politecnica de Valencia, Camino de Vera 14, 46022 Valencia (Spain)

2009-11-15

Hydrogen is a promising energy vector; however, finding methods to produce it from renewable sources is essential to allow its wide-scale use. In that line, biological hydrogen production, although it is considered as a possible alternative, requires substantial improvements to overcome its present low yields. In that direction, genetic manipulation probably will play a central role and from that point of view metabolic flux analysis (MFA) constitutes an important tool to guide a priori most suitable genetic modifications oriented to a hydrogen yield increase. In this work MFA has been applied to analyze hydrogen photoproduction of Synechocystis sp. PCC6803. Flux analysis was carried out based on literature data and several basic fluxes were estimated in different growing conditions of the system. From this analysis, an upper limit for hydrogen photoproduction has been determined indicating a wide margin for improvement. MFA was also used to find a feasible operating space for hydrogen production, which avoids oxygen inhibition, one of the most important limitations to make hydrogen production cost effective. In addition, a set of biotechnological strategies are proposed that would be consistent with the performed mathematical analysis. (author)

Plant synthetic biology.

Science.gov (United States)

Liu, Wusheng; Stewart, C Neal

2015-05-01

Plant synthetic biology is an emerging field that combines engineering principles with plant biology toward the design and production of new devices. This emerging field should play an important role in future agriculture for traditional crop improvement, but also in enabling novel bioproduction in plants. In this review we discuss the design cycles of synthetic biology as well as key engineering principles, genetic parts, and computational tools that can be utilized in plant synthetic biology. Some pioneering examples are offered as a demonstration of how synthetic biology can be used to modify plants for specific purposes. These include synthetic sensors, synthetic metabolic pathways, and synthetic genomes. We also speculate about the future of synthetic biology of plants. Copyright © 2015 Elsevier Ltd. All rights reserved.

Hydrogen peroxide production and myo-inositol metabolism as important traits for virulence of Mycoplasma hyopneumoniae.

Science.gov (United States)

Ferrarini, M G; Mucha, S G; Parrot, D; Meiffren, G; Bachega, J F R; Comte, G; Zaha, A; Sagot, M F

2018-04-06

Mycoplasma hyopneumoniae is the causative agent of enzootic pneumonia. In our previous work, we reconstructed the metabolic models of this species along with two other mycoplasmas from the respiratory tract of swine: Mycoplasma hyorhinis, considered less pathogenic but which nonetheless causes disease and Mycoplasma flocculare, a commensal bacterium. We identified metabolic differences that partially explained their different levels of pathogenicity. One important trait was the production of hydrogen peroxide from the glycerol metabolism only in the pathogenic species. Another important feature was a pathway for the metabolism of myo-inositol in M. hyopneumoniae. Here, we tested these traits to understand their relation to the different levels of pathogenicity, comparing not only the species but also pathogenic and attenuated strains of M. hyopneumoniae. Regarding the myo-inositol metabolism, we show that only M. hyopneumoniae assimilated this carbohydrate and remained viable when myo-inositol was the primary energy source. Strikingly, only the two pathogenic strains of M. hyopneumoniae produced hydrogen peroxide in complex medium. We also show that this production was dependent on the presence of glycerol. Although further functional tests are needed, we present in this work two interesting metabolic traits of M. hyopneumoniae that might be directly related to its enhanced virulence. This article is protected by copyright. All rights reserved. © 2018 John Wiley & Sons Ltd.

Oxygen and hydrogen isotope fractionation during cellulose metabolism in Lemna gibba L

International Nuclear Information System (INIS)

Yakir, D.; DeNiro, M.J.

1990-01-01

Lemna gibba L. B3 was grown under heterotrophic, photoheterotrophic, and autotrophic conditions in water having a variety of hydrogen and oxygen isotopic compositions. The slopes of the linear regression lines between the isotopic composition of water and leaf cellulose indicated that under the three growth conditions about 40, 70, and 100% of oxygens and carbon-bound hydrogens of cellulose exchanged with those of water prior to cellulose formation. Using the equations of the linear relationships, we estimated the overall fractionation factors between water and the exchanged oxygen and carbon bound-hydrogen of cellulose. At least two very different isotope effects must determine the hydrogen isotopic composition of Lemna cellulose. One reflects the photosynthetic reduction of NADP, while the second reflects exchange reactions that occur subsequent to NADP reduction. Oxygen isotopic composition of cellulose apparently is determined by a single type of exchange reaction with water. Under different growth conditions, variations in metabolic fluxes affect the hydrogen isotopic composition of cellulose by influencing the extent to which the two isotope effects mentioned above are recorded. The oxygen isotopic composition of cellulose is not affected by such changes in growth conditions

Kinetics of butyrate, acetate, and hydrogen metabolism in a thermophilic, anaerobic, butyrate-degrading triculture.

Science.gov (United States)

Ahring, B K; Westermann, P

1987-02-01

Kinetics of butyrate, acetate, and hydrogen metabolism were determined with butyrate-limited, chemostat-grown tricultures of a thermophilic butyrate-utilizing bacterium together with Methanobacterium thermoautotrophicum and the TAM organism, a thermophilic acetate-utilizing methanogenic rod. Kinetic parameters were determined from progress curves fitted to the integrated form of the Michaelis-Menten equation. The apparent half-saturation constants, K(m), for butyrate, acetate, and dissolved hydrogen were 76 muM, 0.4 mM, and 8.5 muM, respectively. Butyrate and hydrogen were metabolized to a concentration of less than 1 muM, whereas acetate uptake usually ceased at a concentration of 25 to 75 muM, indicating a threshold level for acetate uptake. No significant differences in K(m) values for butyrate degradation were found between chemostat- and batch-grown tricultures, although the maximum growth rate was somewhat higher in the batch cultures in which the medium was supplemented with yeast extract. Acetate utilization was found to be the rate-limiting reaction for complete degradation of butyrate to methane and carbon dioxide in continuous culture. Increasing the dilution rate resulted in a gradual accumulation of acetate. The results explain the low concentrations of butyrate and hydrogen normally found during anaerobic digestion and the observation that acetate is the first volatile fatty acid to accumulate upon a decrease in retention time or increase in organic loading of a digestor.

Asymmetric transfer hydrogenation by synthetic catalysts in cancer cells

Science.gov (United States)

Coverdale, James P. C.; Romero-Canelón, Isolda; Sanchez-Cano, Carlos; Clarkson, Guy J.; Habtemariam, Abraha; Wills, Martin; Sadler, Peter J.

2018-03-01

Catalytic anticancer metallodrugs active at low doses could minimize side-effects, introduce novel mechanisms of action that combat resistance and widen the spectrum of anticancer-drug activity. Here we use highly stable chiral half-sandwich organometallic Os(II) arene sulfonyl diamine complexes, [Os(arene)(TsDPEN)] (TsDPEN, N-(p-toluenesulfonyl)-1,2-diphenylethylenediamine), to achieve a highly enantioselective reduction of pyruvate, a key intermediate in metabolic pathways. Reduction is shown both in aqueous model systems and in human cancer cells, with non-toxic concentrations of sodium formate used as a hydride source. The catalytic mechanism generates selectivity towards ovarian cancer cells versus non-cancerous fibroblasts (both ovarian and lung), which are commonly used as models of healthy proliferating cells. The formate precursor N-formylmethionine was explored as an alternative to formate in PC3 prostate cancer cells, which are known to overexpress a deformylase enzyme. Transfer-hydrogenation catalysts that generate reductive stress in cancer cells offer a new approach to cancer therapy.

Synthetic biology and metabolic engineering for marine carotenoids: new opportunities and future prospects.

Science.gov (United States)

Wang, Chonglong; Kim, Jung-Hun; Kim, Seon-Won

2014-09-17

Carotenoids are a class of diverse pigments with important biological roles such as light capture and antioxidative activities. Many novel carotenoids have been isolated from marine organisms to date and have shown various utilizations as nutraceuticals and pharmaceuticals. In this review, we summarize the pathways and enzymes of carotenoid synthesis and discuss various modifications of marine carotenoids. The advances in metabolic engineering and synthetic biology for carotenoid production are also reviewed, in hopes that this review will promote the exploration of marine carotenoid for their utilizations.

Biofuel production in Escherichia coli. The role of metabolic engineering and synthetic biology

Energy Technology Data Exchange (ETDEWEB)

Clomburg, James M. [Rice Univ., Houston, TX (United States). Dept. of Chemical and Biomolecular Engineering; Gonzalez, Ramon [Rice Univ., Houston, TX (United States). Dept. of Chemical and Biomolecular Engineering; Rice Univ., Houston, TX (United States). Dept. of Bioengineering

2010-03-15

The microbial production of biofuels is a promising avenue for the development of viable processes for the generation of fuels from sustainable resources. In order to become cost and energy effective, these processes must utilize organisms that can be optimized to efficiently produce candidate fuels from a variety of feedstocks. Escherichia coli has become a promising host organism for the microbial production of biofuels in part due to the ease at which this organism can be manipulated. Advancements in metabolic engineering and synthetic biology have led to the ability to efficiently engineer E. coli as a biocatalyst for the production of a wide variety of potential biofuels from several biomass constituents. This review focuses on recent efforts devoted to engineering E. coli for the production of biofuels, with emphasis on the key aspects of both the utilization of a variety of substrates as well as the synthesis of several promising biofuels. Strategies for the efficient utilization of carbohydrates, carbohydrate mixtures, and noncarbohydrate carbon sources will be discussed along with engineering efforts for the exploitation of both fermentative and nonfermentative pathways for the production of candidate biofuels such as alcohols and higher carbon biofuels derived from fatty acid and isoprenoid pathways. Continued advancements in metabolic engineering and synthetic biology will help improve not only the titers, yields, and productivities of biofuels discussed herein, but also increase the potential range of compounds that can be produced. (orig.)

Synthetic Biology and Metabolic Engineering for Marine Carotenoids: New Opportunities and Future Prospects

Directory of Open Access Journals (Sweden)

Chonglong Wang

2014-09-01

Full Text Available Carotenoids are a class of diverse pigments with important biological roles such as light capture and antioxidative activities. Many novel carotenoids have been isolated from marine organisms to date and have shown various utilizations as nutraceuticals and pharmaceuticals. In this review, we summarize the pathways and enzymes of carotenoid synthesis and discuss various modifications of marine carotenoids. The advances in metabolic engineering and synthetic biology for carotenoid production are also reviewed, in hopes that this review will promote the exploration of marine carotenoid for their utilizations.

Synthetic Biology and Metabolic Engineering for Marine Carotenoids: New Opportunities and Future Prospects

Science.gov (United States)

Wang, Chonglong; Kim, Jung-Hun; Kim, Seon-Won

2014-01-01

Carotenoids are a class of diverse pigments with important biological roles such as light capture and antioxidative activities. Many novel carotenoids have been isolated from marine organisms to date and have shown various utilizations as nutraceuticals and pharmaceuticals. In this review, we summarize the pathways and enzymes of carotenoid synthesis and discuss various modifications of marine carotenoids. The advances in metabolic engineering and synthetic biology for carotenoid production are also reviewed, in hopes that this review will promote the exploration of marine carotenoid for their utilizations. PMID:25233369

Metabolic engineering of microorganisms for biofuels production: from bugs to synthetic biology to fuels

Energy Technology Data Exchange (ETDEWEB)

Kuk Lee, Sung; Chou, Howard; Ham, Timothy S.; Soon Lee, Taek; Keasling, Jay D.

2009-12-02

The ability to generate microorganisms that can produce biofuels similar to petroleum-based transportation fuels would allow the use of existing engines and infrastructure and would save an enormous amount of capital required for replacing the current infrastructure to accommodate biofuels that have properties significantly different from petroleum-based fuels. Several groups have demonstrated the feasibility of manipulating microbes to produce molecules similar to petroleum-derived products, albeit at relatively low productivity (e.g. maximum butanol production is around 20 g/L). For cost-effective production of biofuels, the fuel-producing hosts and pathways must be engineered and optimized. Advances in metabolic engineering and synthetic biology will provide new tools for metabolic engineers to better understand how to rewire the cell in order to create the desired phenotypes for the production of economically viable biofuels.

Analysis of biotechnological hydrogen production efficiency for microorganisms with different types of metabolism, promising directions for further research

Directory of Open Access Journals (Sweden)

Людмила Сергіївна Зубченко

2015-10-01

Full Text Available The basic biotechnological methods of hydrogen production, namely biological water splitting, using algae or cyanobacteria, dark fermentation and bioelectrochemical systems are analyzed in the article. Biochemical features of hydrogen production by microorganisms with different types of metabolism are reviewed. Disadvantages of each method and the prospects for future research are determined

Exacerbation of substrate toxicity by IPTG in Escherichia coli BL21(DE3) carrying a synthetic metabolic pathway.

Science.gov (United States)

Dvorak, Pavel; Chrast, Lukas; Nikel, Pablo I; Fedr, Radek; Soucek, Karel; Sedlackova, Miroslava; Chaloupkova, Radka; de Lorenzo, Víctor; Prokop, Zbynek; Damborsky, Jiri

2015-12-21

Heterologous expression systems based on promoters inducible with isopropyl-β-D-1-thiogalactopyranoside (IPTG), e.g., Escherichia coli BL21(DE3) and cognate LacI(Q)/P(lacUV5)-T7 vectors, are commonly used for production of recombinant proteins and metabolic pathways. The applicability of such cell factories is limited by the complex physiological burden imposed by overexpression of the exogenous genes during a bioprocess. This burden originates from a combination of stresses that may include competition for the expression machinery, side-reactions due to the activity of the recombinant proteins, or the toxicity of their substrates, products and intermediates. However, the physiological impact of IPTG-induced conditional expression on the recombinant host under such harsh conditions is often overlooked. The physiological responses to IPTG of the E. coli BL21(DE3) strain and three different recombinants carrying a synthetic metabolic pathway for biodegradation of the toxic anthropogenic pollutant 1,2,3-trichloropropane (TCP) were investigated using plating, flow cytometry, and electron microscopy. Collected data revealed unexpected negative synergistic effect of inducer of the expression system and toxic substrate resulting in pronounced physiological stress. Replacing IPTG with the natural sugar effector lactose greatly reduced such stress, demonstrating that the effect was due to the original inducer's chemical properties. IPTG is not an innocuous inducer; instead, it exacerbates the toxicity of haloalkane substrate and causes appreciable damage to the E. coli BL21(DE3) host, which is already bearing a metabolic burden due to its content of plasmids carrying the genes of the synthetic metabolic pathway. The concentration of IPTG can be effectively tuned to mitigate this negative effect. Importantly, we show that induction with lactose, the natural inducer of P lac , dramatically lightens the burden without reducing the efficiency of the synthetic TCP degradation

Cytochrome P450-mediated metabolism of the synthetic cannabinoids UR-144 and XLR-11

DEFF Research Database (Denmark)

Nielsen, Line Marie; Holm, Niels Bjerre; Olsen, Lars

2016-01-01

In recent years, synthetic cannabinoids have emerged in the illicit drug market, in particular via the Internet, leading to abuse of these drugs. There is currently limited knowledge about the specific enzymes involved in the metabolism of these drugs. In this study, we investigated the cytochrome...... of UR-144 and XLR-11, while inhibition of the other CYP enzymes in HLM had only minor effects. Thus, CYP3A4 is the major contributor to the CYP mediated metabolism of UR-144 and XLR-11 with minor contributions from CYP1A2. Users of UR-144 and XLR-11 are thus subject to the influence of potential drug-drug...... interactions, if they are concomitantly medicated with CYP3A4 inducers (e.g. some antiepileptics) or inhibitors (e.g. some antifungal drugs). Copyright © 2015 John Wiley & Sons, Ltd....

The impact of furfural concentrations and substrate-to-biomass ratios on biological hydrogen production from synthetic lignocellulosic hydrolysate using mesophilic anaerobic digester sludge.

Science.gov (United States)

Akobi, Chinaza; Hafez, Hisham; Nakhla, George

2016-12-01

This study evaluated the impact of furfural (a furan derivative) on hydrogen production rates and yields at initial substrate-to-microorganism ratios (S°/X°) of 4, 2, 1, and 0.5gCOD/gVSS and furfural concentrations of 4, 2, 1, and 0.5g/L. Fermentation studies were carried out in batches using synthetic lignocellulosic hydrolysate as substrate and mesophilic anaerobic digester sludge as seed. Contrary to other literature studies where furfural was inhibitory, this study showed that furfural concentrations of up to 1g/L enhanced hydrogen production with yields as high as 19% from the control (batch without furfural). Plots of hydrogen yields against gfurfural/gsugars and hydrogen yields versus gfurfural/gbiomass showed negative linear correlation indicating that these parameters influence biohydrogen production. Regression analysis indicated that gfurfural/gsugars initial exerted a greater effect on the degree of inhibition of hydrogen production than gfurfural/gVSS final . Copyright © 2016 Elsevier Ltd. All rights reserved.

CHARACTERISTICS OF METABOLISM AND WORKING OUT THE METHODS OF DETERMINATION OF SYNTHETIC CANNABINOID THJ-2201 IN THE URINE OF LABORATORY ANIMALS

Directory of Open Access Journals (Sweden)

D. Yu. Apushkin

2017-01-01

Full Text Available The proposed article touches upon the study of metabolism of new synthetic cannabinoids. In the work the data on synthetic cannabinoid 3-(Naftalin-1-yloxomethyl-1-(5-fluoropentyl-1H-indazole (THJ-2201, as well as the products of its metabolism in the laboratory rats of the Wistar line are given, i. e. Mass spectra and chromatograms of the native substance (THJ-2201 obtained by high-performance liquid chromatography with mass-selective detection (HPLC-MS and gas chromatography with mass-selective detection (GC-MS are given. The paper presents a complex technique for qualitative determination of cannabimimetics THJ-2201 and methods for obtaining a metabolic profile model for the test substance that can be useful for the tasks of qualitative detection and detection of new psychoactive substances in biological objects for the purposes of forensic analysis.The aim of this work was to develop methods for determination of the test substance (THJ-2201 and its metabolites in the urine of laboratory animals, as well as the study of the metabolic characteristics of synthetic cannabinoids on the whole.Materials and methods. The following equipment was used for the experiment: a liquid chromatograph from the firm “Shimadzu LCMC-8050” in combination with a mass-selective detector. The detector type is a triple quadrupole with a double ionization source (chemical ionization at atmospheric pressure and electrospray. The separation of the substances occurred in a chromatographic column (the material is stainless steel, the characteristics are: 150 * 3.0 mm, Luna 3uC18 (2, 100A. The Sorbent is reversed-phase. The investigations were carried out on Agilent 7890A gas chromatograph with Agilent 5975C mass spectrometer and a 103 polar HP-5ms column of 28 m × 0.25 mm. The animals were mature male white laboratory rats of the Wistar line, aged 4–6 months, weighing 190-230 grams.Results and discussion. As a result of the studies, a comprehensive methodology for

Saga of hydrogen civilization

Energy Technology Data Exchange (ETDEWEB)

Veziroglu, T.N. [Clean Energy Research Inst., Univ. of Miami, Coral Gables, Florida (United States)

2009-07-01

'Full text': Fossil fuels (i.e., petroleum, natural gas and coal), which meet most of the world's energy demand today, are being depleted quickly. Also, their combustion products are causing global problems such as the greenhouse effect, ozone layer depletion, acid rains and pollution, all of which are posing great danger for our environment and eventually for the life on our planet. Many engineers and scientists agree that the solution to these global problems would be to replace the existing fossil fuel system by the hydrogen energy system. Hydrogen is a very efficient and clean fuel. Its combustion will produce no greenhouse gases, no ozone layer depleting chemicals, and little or no acid rain ingredients and pollution. Hydrogen, produced from renewable energy (e.g., solar) sources, would result in a permanent energy system which we would never have to change. However, there are other energy systems proposed for the post-petroleum era, such as a synthetic fossil fuel system. In this system, synthetic gasoline and synthetic natural gas will be produced using abundant deposits of coal. In a way, this will ensure the continuation of the present fossil fuel system. The two possible energy systems for the post-fossil fuel era (i.e., the solar-hydrogen energy system and the synthetic fossil fuel system) are compared with the present fossil fuel system by taking into consideration production costs, environmental damages and utilization efficiencies. The results indicate that the solar-hydrogen energy system is the best energy system to ascertain a sustainable future, and it should replace the fossil fuel system before the end of the 21st century. (author)

Saga of hydrogen civilization

International Nuclear Information System (INIS)

Veziroglu, T.N.

2009-01-01

'Full text': Fossil fuels (i.e., petroleum, natural gas and coal), which meet most of the world's energy demand today, are being depleted quickly. Also, their combustion products are causing global problems such as the greenhouse effect, ozone layer depletion, acid rains and pollution, all of which are posing great danger for our environment and eventually for the life on our planet. Many engineers and scientists agree that the solution to these global problems would be to replace the existing fossil fuel system by the hydrogen energy system. Hydrogen is a very efficient and clean fuel. Its combustion will produce no greenhouse gases, no ozone layer depleting chemicals, and little or no acid rain ingredients and pollution. Hydrogen, produced from renewable energy (e.g., solar) sources, would result in a permanent energy system which we would never have to change. However, there are other energy systems proposed for the post-petroleum era, such as a synthetic fossil fuel system. In this system, synthetic gasoline and synthetic natural gas will be produced using abundant deposits of coal. In a way, this will ensure the continuation of the present fossil fuel system. The two possible energy systems for the post-fossil fuel era (i.e., the solar-hydrogen energy system and the synthetic fossil fuel system) are compared with the present fossil fuel system by taking into consideration production costs, environmental damages and utilization efficiencies. The results indicate that the solar-hydrogen energy system is the best energy system to ascertain a sustainable future, and it should replace the fossil fuel system before the end of the 21st century. (author)

A synthetic multifunctional mammalian pH sensor and CO2 transgene-control device.

Science.gov (United States)

Ausländer, David; Ausländer, Simon; Charpin-El Hamri, Ghislaine; Sedlmayer, Ferdinand; Müller, Marius; Frey, Olivier; Hierlemann, Andreas; Stelling, Jörg; Fussenegger, Martin

2014-08-07

All metabolic activities operate within a narrow pH range that is controlled by the CO2-bicarbonate buffering system. We hypothesized that pH could serve as surrogate signal to monitor and respond to the physiological state. By functionally rewiring the human proton-activated cell-surface receptor TDAG8 to chimeric promoters, we created a synthetic signaling cascade that precisely monitors extracellular pH within the physiological range. The synthetic pH sensor could be adjusted by organic acids as well as gaseous CO2 that shifts the CO2-bicarbonate balance toward hydrogen ions. This enabled the design of gas-programmable logic gates, provided remote control of cellular behavior inside microfluidic devices, and allowed for CO2-triggered production of biopharmaceuticals in standard bioreactors. When implanting cells containing the synthetic pH sensor linked to production of insulin into type 1 diabetic mice developing diabetic ketoacidosis, the prosthetic network automatically scored acidic pH and coordinated an insulin expression response that corrected ketoacidosis. Copyright © 2014 Elsevier Inc. All rights reserved.

Metabolic-flux analysis of hydrogen production pathway in Citrobacter amalonaticus Y19

Energy Technology Data Exchange (ETDEWEB)

Oh, You-Kwan; Kim, Mi-Sun [Bioenergy Research Center, Korea Institute of Energy Research, Daejeon 305-343 (Korea); Kim, Heung-Joo; Park, Sunghoon [Department of Chemical and Biochemical Engineering and Institute for Environmental Technology and Industry, Pusan National University, Busan 609-735 (Korea); Ryu, Dewey D.Y. [Biochemical Engineering Program, Department of Chemical Engineering and Material Science, University of California, Davis, CA 95616 (United States)

2008-03-15

For the newly isolated chemoheterotrophic bacterium Citrobacter amalonaticus Y19, anaerobic glucose metabolism and hydrogen (H{sub 2}) production pathway were studied using batch cultivation and an in silico metabolic-flux analysis. Batch cultivation was conducted under varying initial glucose concentration between 1.5 and 9.5 g/L with quantitative measurement of major metabolites to obtain accurate carbon material balance. The metabolic flux of Y19 was analyzed using a metabolic-pathway model which was constructed from 81 biochemical reactions. The linear optimization program MetaFluxNet was employed for the analysis. When the specific growth rate of cells was chosen as an objective function, the model described the batch culture characteristics of Ci. amalonaticus Y19 reasonably well. When the specific H{sub 2} production rate was selected as an objective function, on the other hand, the achievable maximal H{sub 2} production yield (8.7molH{sub 2}/mol glucose) and the metabolic pathway enabling the high H{sub 2} yield were identified. The pathway involved non-native NAD(P)-linked hydrogenase and H{sub 2} production from NAD(P)H which were supplied at a high rate from glucose degradation through the pentose phosphate pathway. (author)

Synthetic nanocomposite MgH2/5 wt. % TiMn2 powders for solid-hydrogen storage tank integrated with PEM fuel cell.

Science.gov (United States)

El-Eskandarany, M Sherif; Shaban, Ehab; Aldakheel, Fahad; Alkandary, Abdullah; Behbehani, Montaha; Al-Saidi, M

2017-10-16

Storing hydrogen gas into cylinders under high pressure of 350 bar is not safe and still needs many intensive studies dedic ated for tank's manufacturing. Liquid hydrogen faces also severe practical difficulties due to its very low density, leading to larger fuel tanks three times larger than traditional gasoline tank. Moreover, converting hydrogen gas into liquid phase is not an economic process since it consumes high energy needed to cool down the gas temperature to -252.8 °C. One practical solution is storing hydrogen gas in metal lattice such as Mg powder and its nanocomposites in the form of MgH 2 . There are two major issues should be solved first. One related to MgH 2 in which its inherent poor hydrogenation/dehydrogenation kinetics and high thermal stability must be improved. Secondly, related to providing a safe tank. Here we have succeeded to prepare a new binary system of MgH 2 /5 wt. % TiMn 2 nanocomposite powder that show excellent hydrogenation/dehydrogenation behavior at relatively low temperature (250 °C) with long cycle-life-time (1400 h). Moreover, a simple hydrogen storage tank filled with our synthetic nanocomposite powders was designed and tested in electrical charging a battery of a cell phone device at 180 °C through a commercial fuel cell.

Probing the redox metabolism in the strictly anaerobic, extremely thermophilic, hydrogen-producing Caldicellulosiruptor saccharolyticus using amperometry

DEFF Research Database (Denmark)

Kostesha, Natalie; Willquist, Karin; Emnéus, Jenny

2011-01-01

Changes in the redox metabolism in the anaerobic, extremely thermophilic, hydrogen-forming bacterium Caldicellulosiruptor saccharolyticus were probed for the first time in vivo using mediated amperometry with ferricyanide as a thermotolerant external mediator. Clear differences in the intracellul...... in the intracellular electron flow and to probe redox enzyme properties of a strictly anaerobic thermophile in vivo.......Changes in the redox metabolism in the anaerobic, extremely thermophilic, hydrogen-forming bacterium Caldicellulosiruptor saccharolyticus were probed for the first time in vivo using mediated amperometry with ferricyanide as a thermotolerant external mediator. Clear differences in the intracellular...... the NADH-dependent lactate dehydrogenase, upon which more NADH was directed to membrane-associated enzymes for ferricyanide reduction, leading to a higher electrochemical signal. The method is noninvasive and the results presented here demonstrate that this method can be used to accurately detect changes...

A study of positron properties in quartz crystals and synthetic silica glass

International Nuclear Information System (INIS)

Anwand, W.; Brauer, G.; Hesegawa, M.; Dersch, O.; Rauch, F.

2001-01-01

The monoenergetic positron beamline 'SPONSOR' at Rossendorf has been used to investigate the positron behaviour in a naturally grown Brasilian quartz, two synthetic quartz crystals of different origin, and synthetic silica glass. The measurements allow us to obtain the positron diffusion length of free positrons and Bloch para-positronium, if formed, in these materials. In addition, hydrothermal treatment of a synthetic quartz has been used to introduce hydrogen into the crystal up to a certain depth. The presence of hydrogen is found to influence the formation of para-positronium. The depth distribution of hydrogen has been measured independently by the nuclear reaction analysis, and will be discussed in comparison with the results deduced from the positron studies. (author)

Adsorption of hydrogen gas and redox processes in clays.

Science.gov (United States)

Didier, Mathilde; Leone, Laura; Greneche, Jean-Marc; Giffaut, Eric; Charlet, Laurent

2012-03-20

In order to assess the adsorption properties of hydrogen gas and reactivity of adsorbed hydrogen, we measured H(2)(g) adsorption on Na synthetic montmorillonite-type clays and Callovo-Oxfordian (COx) clayrock using gas chromatography. Synthetic montmorillonites with increasing structural Fe(III) substitution (0 wt %, 3.2 wt %, and 6.4 wt % Fe) were used. Fe in the synthetic montmorillonites is principally present as structural Fe(III) ions. We studied the concomitant reduction of structural Fe(III) in the clays using (57)Fe Mössbauer spectrometry. The COx, which mainly contains smectite/illite and calcite minerals, is also studied together with the pure clay fraction of this clayrock. Experiments were performed with dry clay samples which were reacted with hydrogen gas at 90 and 120 °C for 30 to 45 days at a hydrogen partial pressure close to 0.45 bar. Results indicate that up to 0.11 wt % of hydrogen is adsorbed on the clays at 90 °C under 0.45 bar of relative pressure. (57)Fe Mössbauer spectrometry shows that up to 6% of the total structural Fe(III) initially present in these synthetic clays is reduced upon adsorption of hydrogen gas. No reduction is observed with the COx sample in the present experimental conditions.

Metabolic engineering of β-oxidation in Penicillium chrysogenum for improved semi-synthetic cephalosporin biosynthesis.

Science.gov (United States)

Veiga, Tânia; Gombert, Andreas K; Landes, Nils; Verhoeven, Maarten D; Kiel, Jan A K W; Krikken, Arjen M; Nijland, Jeroen G; Touw, Hesselien; Luttik, Marijke A H; van der Toorn, John C; Driessen, Arnold J M; Bovenberg, Roel A L; van den Berg, Marco A; van der Klei, Ida J; Pronk, Jack T; Daran, Jean-Marc

2012-07-01

Industrial production of semi-synthetic cephalosporins by Penicillium chrysogenum requires supplementation of the growth media with the side-chain precursor adipic acid. In glucose-limited chemostat cultures of P. chrysogenum, up to 88% of the consumed adipic acid was not recovered in cephalosporin-related products, but used as an additional carbon and energy source for growth. This low efficiency of side-chain precursor incorporation provides an economic incentive for studying and engineering the metabolism of adipic acid in P. chrysogenum. Chemostat-based transcriptome analysis in the presence and absence of adipic acid confirmed that adipic acid metabolism in this fungus occurs via β-oxidation. A set of 52 adipate-responsive genes included six putative genes for acyl-CoA oxidases and dehydrogenases, enzymes responsible for the first step of β-oxidation. Subcellular localization of the differentially expressed acyl-CoA oxidases and dehydrogenases revealed that the oxidases were exclusively targeted to peroxisomes, while the dehydrogenases were found either in peroxisomes or in mitochondria. Deletion of the genes encoding the peroxisomal acyl-CoA oxidase Pc20g01800 and the mitochondrial acyl-CoA dehydrogenase Pc20g07920 resulted in a 1.6- and 3.7-fold increase in the production of the semi-synthetic cephalosporin intermediate adipoyl-6-APA, respectively. The deletion strains also showed reduced adipate consumption compared to the reference strain, indicating that engineering of the first step of β-oxidation successfully redirected a larger fraction of adipic acid towards cephalosporin biosynthesis. Copyright © 2012 Elsevier Inc. All rights reserved.

Experimental determination of hydrogen content of oil extract from jatropha seeds

International Nuclear Information System (INIS)

Okunade, I.O.; Jonah, S.A.; Omede, M.O.

2010-01-01

The thermal neutron technique was used for the determination of hydrogen content of oil extract from Jatropha seeds. The experimental arrangement consists of a source holder, Am-Be neutron source embedded in paraffin wax and 3 He detector was used to measure reflection coefficient as a function of hydrogen content of various hydrocarbon materials used as calibration standards. The hydrogen content which is an important property of fuel oils was determined for jatropha oil and jatropha-synthetic diesel using their measured values of neutron reflection coefficients and calibration data. The result obtained showed that the hydrogen content of Jatropha oil exceeds that of the synthetic diesel, thus indicating its suitability as a fuel oil for powering diesel engines. The results obtained also indicated that hydrogen content of jatropha-synthetic diesel mixture increases as the volumetric concentration of jatropha oil in the mixture increases, indicating that jatropha oil can serve as a suitable additive to synthetic diesel oil.

Investigation of the microbial metabolism of carbon dioxide and hydrogen in the kangaroo foregut by stable isotope probing.

Science.gov (United States)

Godwin, Scott; Kang, Alicia; Gulino, Lisa-Maree; Manefield, Mike; Gutierrez-Zamora, Maria-Luisa; Kienzle, Marco; Ouwerkerk, Diane; Dawson, Kerri; Klieve, Athol V

2014-09-01

Kangaroos ferment forage material in an enlarged forestomach analogous to the rumen, but in contrast to ruminants, they produce little or no methane. The objective of this study was to identify the dominant organisms and pathways involved in hydrogenotrophy in the kangaroo forestomach, with the broader aim of understanding how these processes are able to predominate over methanogenesis. Stable isotope analysis of fermentation end products and RNA stable isotope probing (RNA-SIP) were used to investigate the organisms and biochemical pathways involved in the metabolism of hydrogen and carbon dioxide in the kangaroo forestomach. Our results clearly demonstrate that the activity of bacterial reductive acetogens is a key factor in the reduced methane output of kangaroos. In in vitro fermentations, the microbial community of the kangaroo foregut produced very little methane, but produced a significantly greater proportion of acetate derived from carbon dioxide than the microbial community of the bovine rumen. A bacterial operational taxonomic unit closely related to the known reductive acetogen Blautia coccoides was found to be associated with carbon dioxide and hydrogen metabolism in the kangaroo foregut. Other bacterial taxa including members of the genera Prevotella, Oscillibacter and Streptococcus that have not previously been reported as containing hydrogenotrophic organisms were also significantly associated with metabolism of hydrogen and carbon dioxide in the kangaroo forestomach.

Metabolism of a new synthetic progestagen, Org 2969, in female volunteers

International Nuclear Information System (INIS)

Viinikka, L.; Ylikorkala, O.; Vihko, R.; Hasenack, H.G.; Nieuwenhuyse, H.

1980-01-01

The metabolism of a new synthetic progestagen, Org 2969 was studied in 4 healthy female volunteers. During the first part of the study (Phase I), the volunteers ingested 50 μg (about 0.1 mCi) of [16- 3 H]Org 2969 together with 50 μg of ethinyloestradiol as a single dose. During the second part of the study (Phase II), a 10-day pre-treatment with the same dosage of non-radioactive compound preceded the administration of the radioactive steroid. A peak level of total radioactivity, representing 3.16-5.02% of the dose given/l of serum, was achieved within 2-3 h in Phase I. During Phase II, the corresponding figures were 4.54-5.13% after 1.5-3 h. The difference was mainly due to an increase of freely-extractable steroids during Phase II. The difference can at least partly be explained by assuming a change in the kinetics of the metabolism of Org 2969 by pre-treatment with Org 2969 and ethinyloestradiol. The mean recovery of radioactivity in urine and faeces was 83.0%/48.1%/34.9% (total/urine/faeces) of the total dose in Phase I and 76.1%/45.2%/30.9% during Phase II. The differences in the total excretion and in the radioactivity excreted in the faeces were significant. (author)

Carbon and hydrogen metabolism of green algae in light and dark

Energy Technology Data Exchange (ETDEWEB)

1990-01-01

After adaptation to a hydrogen metabolism, Chlamydomonas reinhardtii can photoanaerobically metabolize acetate with the evolution of H{sub 2} and CO{sub 2}. An enzyme profile of the chloroplastic, cytoplasmic, and mitochondrial fractions were obtained with a cellular fractionation procedure that incorporated cell wall removal by autolysine, digestion of the plasmalemma with digitonin and fractionation by differential centrifugation on a Percoll step gradient. The sequence of events leading to the photo-evolution of H{sub 2} from acetate includes the conversion of acetate into succinate via the extraplastidic glyoxylate cycle, the oxidation of succinate to fumarate by chloroplastic succinic dehydrogenase and the oxidation of malate to oxaloacetate in the chloroplast by NAD dependent malate dehydrogenase. The level of potential activity of the enzymes was sufficient to accommodate the observed rate of gas evolution. The isolated darkened chloroplast evolves aerobically CO{sub 2} from glucose indicating a chloroplastic respiratory pathway. Evolution of CO{sub 2} is blocked by mitochondrial inhibitors.

Microalgal hydrogen production - A review.

Science.gov (United States)

Khetkorn, Wanthanee; Rastogi, Rajesh P; Incharoensakdi, Aran; Lindblad, Peter; Madamwar, Datta; Pandey, Ashok; Larroche, Christian

2017-11-01

Bio-hydrogen from microalgae including cyanobacteria has attracted commercial awareness due to its potential as an alternative, reliable and renewable energy source. Photosynthetic hydrogen production from microalgae can be interesting and promising options for clean energy. Advances in hydrogen-fuel-cell technology may attest an eco-friendly way of biofuel production, since, the use of H 2 to generate electricity releases only water as a by-product. Progress in genetic/metabolic engineering may significantly enhance the photobiological hydrogen production from microalgae. Manipulation of competing metabolic pathways by modulating the certain key enzymes such as hydrogenase and nitrogenase may enhance the evolution of H 2 from photoautotrophic cells. Moreover, biological H 2 production at low operating costs is requisite for economic viability. Several photobioreactors have been developed for large-scale biomass and hydrogen production. This review highlights the recent technological progress, enzymes involved and genetic as well as metabolic engineering approaches towards sustainable hydrogen production from microalgae. Copyright © 2017 Elsevier Ltd. All rights reserved.

Kinetics of Butyrate, Acetate, and Hydrogen Metabolism in a Thermophilic, Anaerobic, Butyrate-Degrading Triculture

OpenAIRE

Ahring, Birgitte K.; Westermann, Peter

1987-01-01

Kinetics of butyrate, acetate, and hydrogen metabolism were determined with butyrate-limited, chemostat-grown tricultures of a thermophilic butyrate-utilizing bacterium together with Methanobacterium thermoautotrophicum and the TAM organism, a thermophilic acetate-utilizing methanogenic rod. Kinetic parameters were determined from progress curves fitted to the integrated form of the Michaelis-Menten equation. The apparent half-saturation constants, Km, for butyrate, acetate, and dissolved hyd...

Fusion as a source of synthetic fuels

International Nuclear Information System (INIS)

Powell, J.R.; Fillo, J.A.; Steinberg, M.

1981-01-01

In the near-term, coal derived synthetic fuels will be used; but in the long-term, resource depletion and environmental effects will mandate synthetic fuels from inexhaustible sources - fission, fusion, and solar. Of the three sources, fusion appears uniquely suited for the efficient production of hydrogen-based fuels, due to its ability to directly generate very high process temperatures (up to approx. 2000 0 C) for water splitting reactions. Fusion-based water splitting reactions include high temperature electrolysis (HTE) of steam, thermochemical cycles, hybrid electrochemical/thermochemical, and direct thermal decomposition. HTE appears to be the simplest and most efficient process with efficiencies of 50 to 70% (fusion to hydrogen chemical energy), depending on process conditions

Metabolic Engineering and Modeling of Metabolic Pathways to Improve Hydrogen Production by Photosynthetic Bacteria

Energy Technology Data Exchange (ETDEWEB)

Jiao, Y. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Navid, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2014-12-19

traits act as the biocatalysts of the process designed to both enhance the system efficiency of CO₂ fixation and the net hydrogen production rate. Additionally we applied metabolic engineering approaches guided by computational modeling for the chosen model microorganisms to enable efficient hydrogen production.

From noise to synthetic nucleoli: can synthetic biology achieve new insights?

Science.gov (United States)

Ciechonska, Marta; Grob, Alice; Isalan, Mark

2016-04-18

Synthetic biology aims to re-organise and control biological components to make functional devices. Along the way, the iterative process of designing and testing gene circuits has the potential to yield many insights into the functioning of the underlying chassis of cells. Thus, synthetic biology is converging with disciplines such as systems biology and even classical cell biology, to give a new level of predictability to gene expression, cell metabolism and cellular signalling networks. This review gives an overview of the contributions that synthetic biology has made in understanding gene expression, in terms of cell heterogeneity (noise), the coupling of growth and energy usage to expression, and spatiotemporal considerations. We mainly compare progress in bacterial and mammalian systems, which have some of the most-developed engineering frameworks. Overall, one view of synthetic biology can be neatly summarised as "creating in order to understand."

ATF4-Induced Metabolic Reprograming Is a Synthetic Vulnerability of the p62-Deficient Tumor Stroma.

Science.gov (United States)

Linares, Juan F; Cordes, Thekla; Duran, Angeles; Reina-Campos, Miguel; Valencia, Tania; Ahn, Christopher S; Castilla, Elias A; Moscat, Jorge; Metallo, Christian M; Diaz-Meco, Maria T

2017-12-05

Tumors undergo nutrient stress and need to reprogram their metabolism to survive. The stroma may play a critical role in this process by providing nutrients to support the epithelial compartment of the tumor. Here we show that p62 deficiency in stromal fibroblasts promotes resistance to glutamine deprivation by the direct control of ATF4 stability through its p62-mediated polyubiquitination. ATF4 upregulation by p62 deficiency in the stroma activates glucose carbon flux through a pyruvate carboxylase-asparagine synthase cascade that results in asparagine generation as a source of nitrogen for stroma and tumor epithelial proliferation. Thus, p62 directly targets nuclear transcription factors to control metabolic reprogramming in the microenvironment and repress tumorigenesis, and identifies ATF4 as a synthetic vulnerability in p62-deficient tumor stroma. Copyright © 2017 Elsevier Inc. All rights reserved.

Cysteine and hydrogen sulfide in the regulation of metabolism:Insights from genetics and pharmacology

OpenAIRE

Carter, Roderick N; Morton, Nicholas M

2016-01-01

Abstract Obesity and diabetes represent a significant and escalating worldwide health burden. These conditions are characterized by abnormal nutrient homeostasis. One such perturbation is altered metabolism of the sulphur?containing amino acid cysteine. Obesity is associated with elevated plasma cysteine, whereas diabetes is associated with reduced cysteine levels. One mechanism by which cysteine may act is through its enzymatic breakdown to produce hydrogen sulphide (H2S), a gasotransmitter ...

Biological conversion of carbon dioxide and hydrogen into liquid fuels and industrial chemicals.

Science.gov (United States)

Hawkins, Aaron S; McTernan, Patrick M; Lian, Hong; Kelly, Robert M; Adams, Michael W W

2013-06-01

Non-photosynthetic routes for biological fixation of carbon dioxide into valuable industrial chemical precursors and fuels are moving from concept to reality. The development of 'electrofuel'-producing microorganisms leverages techniques in synthetic biology, genetic and metabolic engineering, as well as systems-level multi-omic analysis, directed evolution, and in silico modeling. Electrofuel processes are being developed for a range of microorganisms and energy sources (e.g. hydrogen, formate, electricity) to produce a variety of target molecules (e.g. alcohols, terpenes, alkenes). This review examines the current landscape of electrofuel projects with a focus on hydrogen-utilizing organisms covering the biochemistry of hydrogenases and carbonic anhydrases, kinetic and energetic analyses of the known carbon fixation pathways, and the state of genetic systems for current and prospective electrofuel-producing microorganisms. Copyright © 2013 Elsevier Ltd. All rights reserved.

Production of Fatty Acid-Derived Valuable Chemicals in Synthetic Microbes

International Nuclear Information System (INIS)

Yu, Ai-Qun; Pratomo Juwono, Nina Kurniasih; Leong, Susanna Su Jan; Chang, Matthew Wook

2014-01-01

Fatty acid derivatives, such as hydroxy fatty acids, fatty alcohols, fatty acid methyl/ethyl esters, and fatty alka(e)nes, have a wide range of industrial applications including plastics, lubricants, and fuels. Currently, these chemicals are obtained mainly through chemical synthesis, which is complex and costly, and their availability from natural biological sources is extremely limited. Metabolic engineering of microorganisms has provided a platform for effective production of these valuable biochemicals. Notably, synthetic biology-based metabolic engineering strategies have been extensively applied to refactor microorganisms for improved biochemical production. Here, we reviewed: (i) the current status of metabolic engineering of microbes that produce fatty acid-derived valuable chemicals, and (ii) the recent progress of synthetic biology approaches that assist metabolic engineering, such as mRNA secondary structure engineering, sensor-regulator system, regulatable expression system, ultrasensitive input/output control system, and computer science-based design of complex gene circuits. Furthermore, key challenges and strategies were discussed. Finally, we concluded that synthetic biology provides useful metabolic engineering strategies for economically viable production of fatty acid-derived valuable chemicals in engineered microbes.

Production of Fatty Acid-Derived Valuable Chemicals in Synthetic Microbes

Energy Technology Data Exchange (ETDEWEB)

Yu, Ai-Qun; Pratomo Juwono, Nina Kurniasih [Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (Singapore); Synthetic Biology Research Program, National University of Singapore, Singapore (Singapore); Leong, Susanna Su Jan [Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (Singapore); Synthetic Biology Research Program, National University of Singapore, Singapore (Singapore); Singapore Institute of Technology, Singapore (Singapore); Chang, Matthew Wook, E-mail: bchcmw@nus.edu.sg [Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (Singapore); Synthetic Biology Research Program, National University of Singapore, Singapore (Singapore)

2014-12-23

Fatty acid derivatives, such as hydroxy fatty acids, fatty alcohols, fatty acid methyl/ethyl esters, and fatty alka(e)nes, have a wide range of industrial applications including plastics, lubricants, and fuels. Currently, these chemicals are obtained mainly through chemical synthesis, which is complex and costly, and their availability from natural biological sources is extremely limited. Metabolic engineering of microorganisms has provided a platform for effective production of these valuable biochemicals. Notably, synthetic biology-based metabolic engineering strategies have been extensively applied to refactor microorganisms for improved biochemical production. Here, we reviewed: (i) the current status of metabolic engineering of microbes that produce fatty acid-derived valuable chemicals, and (ii) the recent progress of synthetic biology approaches that assist metabolic engineering, such as mRNA secondary structure engineering, sensor-regulator system, regulatable expression system, ultrasensitive input/output control system, and computer science-based design of complex gene circuits. Furthermore, key challenges and strategies were discussed. Finally, we concluded that synthetic biology provides useful metabolic engineering strategies for economically viable production of fatty acid-derived valuable chemicals in engineered microbes.

21st century's energy: hydrogen energy system

International Nuclear Information System (INIS)

Veziroglu, T. N.

2007-01-01

Fossil fuels (i.e., petroleum, natural gas and coal), which meet most of the world's energy demand today, are being depleted fast. Also, their combustion products are causing the global problems, such as the greenhouse effect, ozone layer depletion, acid rains and pollution, which are posing great danger for our environment and eventually for the life in our planet. Many engineers and scientists agree that the solution to these global problems would be to replace the existing fossil fuel system by the Hydrogen Energy System. Hydrogen is a very efficient and clean fuel. Its combustion will produce no greenhouse gases, no ozone layer depleting chemicals, little or no acid rain ingredients and pollution. Hydrogen, produced from renewable energy (e.g., solar) sources, would result in a permanent energy system, which we would never have to change. However, there are other energy systems proposed for the post-petroleum era, such as a synthetic fossil fuel system. In this system, synthetic gasoline and synthetic natural gas will be produced using abundant deposits of coal. In a way, this will ensure the continuation of the present fossil fuel system. The two possible energy systems for the post-fossil fuel era (i.e., the solar hydrogen energy system and the synthetic fossil fuel system) are compared with the present fossil fuel system by taking into consideration production costs, environmental damages and utilization efficiencies. The results indicate that the solar hydrogen energy system is the best energy system to ascertain a sustainable future, and it should replace the fossil fuel system before the end of the 21st Century

21st Century's energy: Hydrogen energy system

International Nuclear Information System (INIS)

Veziroglu, T. Nejat; Sahin, Suemer

2008-01-01

Fossil fuels (i.e., petroleum, natural gas and coal), which meet most of the world's energy demand today, are being depleted fast. Also, their combustion products are causing the global problems, such as the greenhouse effect, ozone layer depletion, acid rains and pollution, which are posing great danger for our environment and eventually for the life in our planet. Many engineers and scientists agree that the solution to these global problems would be to replace the existing fossil fuel system by the hydrogen energy system. Hydrogen is a very efficient and clean fuel. Its combustion will produce no greenhouse gases, no ozone layer depleting chemicals, little or no acid rain ingredients and pollution. Hydrogen, produced from renewable energy (e.g., solar) sources, would result in a permanent energy system, which we would never have to change. However, there are other energy systems proposed for the post-petroleum era, such as a synthetic fossil fuel system. In this system, synthetic gasoline and synthetic natural gas will be produced using abundant deposits of coal. In a way, this will ensure the continuation of the present fossil fuel system. The two possible energy systems for the post-fossil fuel era (i.e., the solar-hydrogen energy system and the synthetic fossil fuel system) are compared with the present fossil fuel system by taking into consideration production costs, environmental damages and utilization efficiencies. The results indicate that the solar-hydrogen energy system is the best energy system to ascertain a sustainable future, and it should replace the fossil fuel system before the end of the 21st century

Hydrogen production using Rhodopseudomonas palustris WP 3-5 with hydrogen fermentation reactor effluent

International Nuclear Information System (INIS)

Chi-Mei Lee; Kuo-Tsang Hung

2006-01-01

The possibility of utilizing the dark hydrogen fermentation stage effluents for photo hydrogen production using purple non-sulfur bacteria should be elucidated. In the previous experiments, Rhodopseudomonas palustris WP3-5 was proven to efficiently produce hydrogen from the effluent of hydrogen fermentation reactors. The highest hydrogen production rate was obtained at a HRT value of 48 h when feeding a 5 fold effluent dilution from anaerobic hydrogen fermentation. Besides, hydrogen production occurred only when the NH 4 + concentration was below 17 mg-NH 4 + /l. Therefore, for successful fermentation effluent utilization, the most important things were to decrease the optimal HRT, increase the optimal substrate concentration and increase the tolerable ammonia concentration. In this study, a lab-scale serial photo-bioreactor was constructed. The reactor overall hydrogen production efficiency with synthetic wastewater exhibiting an organic acid profile identical to that of anaerobic hydrogen fermentation reactor effluent and with effluent from two anaerobic hydrogen fermentation reactors was evaluated. (authors)

Enhanced energy conversion efficiency from high strength synthetic organic wastewater by sequential dark fermentative hydrogen production and algal lipid accumulation.

Science.gov (United States)

Ren, Hong-Yu; Liu, Bing-Feng; Kong, Fanying; Zhao, Lei; Xing, Defeng; Ren, Nan-Qi

2014-04-01

A two-stage process of sequential dark fermentative hydrogen production and microalgal cultivation was applied to enhance the energy conversion efficiency from high strength synthetic organic wastewater. Ethanol fermentation bacterium Ethanoligenens harbinense B49 was used as hydrogen producer, and the energy conversion efficiency and chemical oxygen demand (COD) removal efficiency reached 18.6% and 28.3% in dark fermentation. Acetate was the main soluble product in dark fermentative effluent, which was further utilized by microalga Scenedesmus sp. R-16. The final algal biomass concentration reached 1.98gL(-1), and the algal biomass was rich in lipid (40.9%) and low in protein (23.3%) and carbohydrate (11.9%). Compared with single dark fermentation stage, the energy conversion efficiency and COD removal efficiency of two-stage system remarkably increased 101% and 131%, respectively. This research provides a new approach for efficient energy production and wastewater treatment using a two-stage process combining dark fermentation and algal cultivation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Determination of hydrogen content of Jatropha biodiesel oil using neutron reflection technique

International Nuclear Information System (INIS)

Okunade, I. O.; Jonah, S. A.; Omede, M.

2014-01-01

Biofuel is an environmental-friendly alternative to fossil fuel and holds immense potential for the future energy needs of the country. Non-edible jatropha biodiesel oil has been identified as one of the suitable bio-fuel options. In this work, experimental measurements were performed to determine the total hydrogen content of jatropha oil and jatropha-synthetic diesel oil mixture. The work was carried out using a neutron reflection facility at the Centre for Energy Research and Training, Ahmadu Bello University, Zaria. Jatropha oil and jatropha-synthetic diesel mixture were subjected to experimental measurements for the purpose of determining bulk hydrogen content using neutron reflection facility that had been previously calibrated using various hydrocarbon materials of known hydrogen content. The hydrogen content of the sample were subsequently determined using their measured neutron reflection coefficient values and calibration data. In general, results obtained indicate high hydrogen content range of 10.68-12.16wt% for jatropha oil and the various jatropha-synthetic diesel mixtures. The implication of this is that jatropha oil or jatrophal-synthetic diesel mixture can be used as alternative fuel to mitigate high carbon monoxide emission.

Rational synthetic pathway refactoring of natural products biosynthesis in actinobacteria.

Science.gov (United States)

Tan, Gao-Yi; Liu, Tiangang

2017-01-01

Natural products (NPs) and their derivatives are widely used as frontline treatments for many diseases. Actinobacteria spp. are used to produce most of NP antibiotics and have also been intensively investigated for NP production, derivatization, and discovery. However, due to the complicated transcriptional and metabolic regulation of NP biosynthesis in Actinobacteria, especially in the cases of genome mining and heterologous expression, it is often difficult to rationally and systematically engineer synthetic pathways to maximize biosynthetic efficiency. With the emergence of new tools and methods in metabolic engineering, the synthetic pathways of many chemicals, such as fatty acids and biofuels, in model organisms (e.g. Escherichia coli ), have been refactored to realize precise and flexible control of production. These studies also offer a promising approach for synthetic pathway refactoring in Actinobacteria. In this review, the great potential of Actinobacteria as a microbial cell factory for biosynthesis of NPs is discussed. To this end, recent progress in metabolic engineering of NP synthetic pathways in Actinobacteria are summarized and strategies and perspectives to rationally and systematically refactor synthetic pathways in Actinobacteria are highlighted. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Chemical Constraints Governing the Origin of Metabolism: The Thermodynamic Landscape of Carbon Group Transformations

Science.gov (United States)

Weber, Arthur L.; Fonda, Mark (Technical Monitor)

2001-01-01

The thermodynamics of organic chemistry under mild aqueous conditions was examined in order to begin to understand its influence on the structure and operation of metabolism and its antecedents. Free energies were estimated for four types reactions of biochemical importance carbon-carbon bond cleavage and synthesis, hydrogen transfer between carbon groups, dehydration of alcohol groups, and aldo-keto isomerization. The energies were calculated for mainly aliphatic groups composed of carbon, hydrogen, and oxygen. The energy values showed that (1) when carbon-carbon bond cleavage involves two different types of functional groups, transfer of the shared electron-pair to the more reduced carbon group is energetically favored over transfer to the more oxidized carbon group, and (2) the energy of carbon-carbon bond transformation is strongly dependent on the type of functional group that donates the shared electron-pair during cleavage, and the group that accepts the shared electron-pair during synthesis, and (3) the energetics of C-C bond transformation is determined primarily by the half-reaction energies of the couples: carbonyl/carboxylic acid, carboxylic acid/carbon dioxide, alcohol/carbonyl, and hydrocarbon/alcohol. The energy of hydrogen-transfer between carbon groups was found to depend on the functional group class of both the hydrogen-donor and hydrogen-acceptor. From these and other observations we concluded that the chemistry of the origin of metabolism (and to a lesser degree modem metabolism) is strongly constrained by the (1) limited disproportionation energy of organic substrates that can be dissipated in a few irreversible reactions, (2) the energy-dominance of few half-reaction couples in carbon-carbon bond transformation that establishes whether a chemical reaction is energetically irreversible, reversible or unfeasible, and (3) the dependence of the transformation-energy on the oxidation state of carbon groups (functional group type) which is

Cell-free synthetic biology for environmental sensing and remediation.

Science.gov (United States)

Karig, David K

2017-06-01

The fields of biosensing and bioremediation leverage the phenomenal array of sensing and metabolic capabilities offered by natural microbes. Synthetic biology provides tools for transforming these fields through complex integration of natural and novel biological components to achieve sophisticated sensing, regulation, and metabolic function. However, the majority of synthetic biology efforts are conducted in living cells, and concerns over releasing genetically modified organisms constitute a key barrier to environmental applications. Cell-free protein expression systems offer a path towards leveraging synthetic biology, while preventing the spread of engineered organisms in nature. Recent efforts in the areas of cell-free approaches for sensing, regulation, and metabolic pathway implementation, as well as for preserving and deploying cell-free expression components, embody key steps towards realizing the potential of cell-free systems for environmental sensing and remediation. Copyright © 2017 The Author. Published by Elsevier Ltd.. All rights reserved.

Synthetic protein scaffolds based on peptide motifs and cognate adaptor domains for improving metabolic productivity

Directory of Open Access Journals (Sweden)

Anselm H.C. Horn

2015-11-01

Full Text Available The efficiency of many cellular processes relies on the defined interaction among different proteins within the same metabolic or signaling pathway. Consequently, a spatial colocalization of functionally interacting proteins has frequently emerged during evolution. This concept has been adapted within the synthetic biology community for the purpose of creating artificial scaffolds. A recent advancement of this concept is the use of peptide motifs and their cognate adaptor domains. SH2, SH3, GBD, and PDZ domains have been used most often in research studies to date. The approach has been successfully applied to the synthesis of a variety of target molecules including catechin, D-glucaric acid, H2, hydrochinone, resveratrol, butyrate, gamma-aminobutyric acid, and mevalonate. Increased production levels of up to 77-fold have been observed compared to non-scaffolded systems. A recent extension of this concept is the creation of a covalent linkage between peptide motifs and adaptor domains, which leads to a more stable association of the scaffolded systems and thus bears the potential to further enhance metabolic productivity.

Synthetic Biology and Personalized Medicine

Science.gov (United States)

Jain, K.K.

2013-01-01

Synthetic biology, application of synthetic chemistry to biology, is a broad term that covers the engineering of biological systems with structures and functions not found in nature to process information, manipulate chemicals, produce energy, maintain cell environment and enhance human health. Synthetic biology devices contribute not only to improve our understanding of disease mechanisms, but also provide novel diagnostic tools. Methods based on synthetic biology enable the design of novel strategies for the treatment of cancer, immune diseases metabolic disorders and infectious diseases as well as the production of cheap drugs. The potential of synthetic genome, using an expanded genetic code that is designed for specific drug synthesis as well as delivery and activation of the drug in vivo by a pathological signal, was already pointed out during a lecture delivered at Kuwait University in 2005. Of two approaches to synthetic biology, top-down and bottom-up, the latter is more relevant to the development of personalized medicines as it provides more flexibility in constructing a partially synthetic cell from basic building blocks for a desired task. PMID:22907209

Adsorption of hydrogen sulfide gas on several synthetic zeolites

Energy Technology Data Exchange (ETDEWEB)

Fukui, T; Ise, Y; Boki, K; Tanada, S

1974-07-01

Ten kinds of synthetic zeolites were tested to determine the most suitable adsorbent for H/sub 2/S gas removal by a dry process. Specific surface area with argon gas and H/sub 2/S gas, surface pH, and thermodynamic data of adsorbents were measured. The amounts of H/sub 2/S gas adsorbed on synthetic zeolite adsorbents were affected in terms of the pore sizes of the adsorbents rather than the surface pH and the thermodynamic factors. The adsorbents No. 3, No. 7, and No. 8 showed higher adsorption of H/sub 2/S than the other adsorbents and were the most suitable for practical purposes.

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

Science.gov (United States)

Jagmann, Nina; Philipp, Bodo

2014-12-20

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

21 CFR 175.250 - Paraffin (synthetic).

Science.gov (United States)

2010-04-01

... hydrocarbons. Lower molecular-weight fractions are removed by distillation. The residue is hydrogenated and may... its components by a solvent separation method, using synthetic isoparaffinic petroleum hydrocarbons... method E131-81a, “Standard Definitions of Terms and Symbols Relating to Molecular-Spectroscopy,” which is...

Specific equilibrium behavior of hydrogen isotopes adsorbed onto synthetic zeolite A-type governed by lithium cations

International Nuclear Information System (INIS)

Takashima, Shoji; Kotoh, Kenji

2013-01-01

Highlights: • Isotherms for H 2 and D 2 adsorbed onto SZ-LiA at 77.4 K are shown. • The adsorption isotherms exhibit specific deviation in the range lower than 10 Pa. • SZ-LiA indicates the power of several 100-times at 0.1 Pa, compared with SZ-NaA. • Experimental isotherms are described empirically by a dual-site Langmuir equation. • The isotope effect on adsorption isotherms appears in the Langmuir constants. -- Abstract: Since synthetic zeolites (SZs) are powerfully adsorptive for hydrogen isotopes at cryogenic temperatures such as liquefied nitrogen, adsorption processes using these have been considered applicable to such as recovery of tritium from the lithium blanket of DT fusion reactor system. Onto these zeolites the adsorptions isotherms for hydrogen isotopes onto SZ-NaA, SZ-CaA and SZ-NaX at 77.4 K were already clarified experimentally and analytically. These isotherms exhibit similar profiles of Langmuir type. In this work, adsorption isotherms were examined for H 2 and D 2 on SZ-LiA at 77.4 K. SZ-LiA was made from SZ-NaA by exchanging its sodium ions for lithium ones, provided by TOSOH Corp. The experimental results demonstrate the specific equilibrium behavior of hydrogen isotopes adsorbed on SZ-LiA, deviating from isothermal profiles on SZ-CaA and SZ-NaX. SZ-LiA show the isothermal profiles of adsorption for H 2 and D 2 similar to on the conventional zeolites in the range from around 1 kPa to the atmospheric pressure, but exhibit a plateau around 1 mol/kg between 0.1 Pa and 100 Pa, while other zeolites show linearly profiling isotherms. This deviation indicates the adsorptive power of SZ-LiA remarkably greater than that of the others

Nuclear power and hydrogen

International Nuclear Information System (INIS)

Welch, Robert.

1982-06-01

Ontario has been using CANDU reactors to produce electricity since 1962. The province does not have an electricity shortage, but it does have a shortage of liquid fuels. The government of Ontario is encouraging research into the production of hydrogen using electricity generated by a dedicated nuclear plant, and the safe and economical use of hydrogen both in the production of synthetic petroleum fuels and as a fuel in its own right

Synthetic fuels and fusion

Energy Technology Data Exchange (ETDEWEB)

Fillo, J A; Powell, J; Steinberg, M [Brookhaven National Lab., Upton, NY (USA)

1981-03-01

The decreasing availability of fossil fuels emphasizes the need to develop systems which will produce synthetic fuel to substitute for and supplement the natural supply. An important first step in the synthesis of liquid and gaseous fuels is the production of hydrogen. Thermonuclear fusion offers an inexhaustible source of energy for the production of hydrogen from water. Depending on design, electric generation efficiencies of approx. equal to 40-60% and hydrogen production efficiencies by high temperature electrolysis of approx. equal to 50-70% are projected for fusion reactors using high temperature blankets. Fusion/coal symbiotic systems appear economically promising for the first generation of commercial fusion synfuels plants. Coal production requirements and the environmental effects of large-scale coal usage would be greatly reduced by a fusion/coal system. In the long-term, there could be a gradual transition to an inexhaustible energy system based solely on fusion.

Fusion Energy for Hydrogen Production

Energy Technology Data Exchange (ETDEWEB)

Fillo, J. A.; Powell, J. R.; Steinberg, M.; Salzano, F.; Benenati, R.; Dang, V.; Fogelson, S.; Isaacs, H.; Kouts, H.; Kushner, M.; Lazareth, O.; Majeski, S.; Makowitz, H.; Sheehan, T. V.

1978-09-01

The decreasing availability of fossil fuels emphasizes the need to develop systems which will produce synthetic fuel to substitute for and supplement the natural supply. An important first step in the synthesis of liquid and gaseous fuels is the production of hydrogen. Thermonuclear fusion offers an inexhaustible source of energy for the production of hydrogen from water. Depending on design, electric generation efficiencies of approximately 40 to 60% and hydrogen production efficiencies by high temperature electrolysis of approximately 50 to 70% are projected for fusion reactors using high temperature blankets.

Hydrothermal Gasification Of Synthetic Liquefied Wood To Methane

Energy Technology Data Exchange (ETDEWEB)

Waldner, M.H.; De Boni, E.; Vogel, F.

2005-03-01

Biomass can be effectively converted to synthetic natural gas (SNG) in a hydrothermal environment. Lower temperatures favor the production of methane rather than hydrogen. At around 420 C, catalysts are needed to ensure reasonable rates of reaction. They are tested in a new rig in terms of activity, selectivity and stability. Gold-plated surfaces ensure no interference from the stainless steel. Experiments were carried out using different feeds, such as ethanol and synthetic liquefied wood. (author)

[New materia medica project: synthetic biology based bioactive metabolites research in medicinal plant].

Science.gov (United States)

Wang, Yong

2017-03-25

In the last decade, synthetic biology research has been gradually transited from monocellular parts or devices toward more complex multicellular systems. The emerging plant synthetic biology is regarded as the "next chapter" of synthetic biology. The complex and diverse plant metabolism as the entry point, plant synthetic biology research not only helps us understand how real life is working, but also facilitates us to learn how to design and construct more complex artificial life. Bioactive compounds innovation and large-scale production are expected to be breakthrough with the redesigned plant metabolism as well. In this review, we discuss the research progress in plant synthetic biology and propose the new materia medica project to lift the level of traditional Chinese herbal medicine research.

A Synthetic Alternative to Canonical One-Carbon Metabolism.

Science.gov (United States)

Bouzon, Madeleine; Perret, Alain; Loreau, Olivier; Delmas, Valérie; Perchat, Nadia; Weissenbach, Jean; Taran, Frédéric; Marlière, Philippe

2017-08-18

One-carbon metabolism is an ubiquitous metabolic pathway that encompasses the reactions transferring formyl-, hydroxymethyl- and methyl-groups bound to tetrahydrofolate for the synthesis of purine nucleotides, thymidylate, methionine and dehydropantoate, the precursor of coenzyme A. An alternative cyclic pathway was designed that substitutes 4-hydroxy-2-oxobutanoic acid (HOB), a compound absent from known metabolism, for the amino acids serine and glycine as one-carbon donors. It involves two novel reactions, the transamination of l-homoserine and the transfer of a one-carbon unit from HOB to tetrahydrofolate releasing pyruvate as coproduct. Since canonical reactions regenerate l-homoserine from pyruvate by carboxylation and subsequent reduction, every one-carbon moiety made available for anabolic reactions originates from CO 2 . The HOB-dependent pathway was established in an Escherichia coli auxotroph selected for prototrophy using long-term cultivation protocols. Genetic, metabolic and biochemical evidence support the emergence of a functional HOB-dependent one-carbon pathway achieved with the recruitment of the two enzymes l-homoserine transaminase and HOB-hydroxymethyltransferase and of HOB as an essential metabolic intermediate. Escherichia coli biochemical reprogramming was achieved by minimally altering canonical metabolism and leveraging on natural selection mechanisms, thereby launching the resulting strain on an evolutionary trajectory diverging from all known extant species.

The path to next generation biofuels: successes and challenges in the era of synthetic biology

Science.gov (United States)

2010-01-01

Volatility of oil prices along with major concerns about climate change, oil supply security and depleting reserves have sparked renewed interest in the production of fuels from renewable resources. Recent advances in synthetic biology provide new tools for metabolic engineers to direct their strategies and construct optimal biocatalysts for the sustainable production of biofuels. Metabolic engineering and synthetic biology efforts entailing the engineering of native and de novo pathways for conversion of biomass constituents to short-chain alcohols and advanced biofuels are herewith reviewed. In the foreseeable future, formal integration of functional genomics and systems biology with synthetic biology and metabolic engineering will undoubtedly support the discovery, characterization, and engineering of new metabolic routes and more efficient microbial systems for the production of biofuels. PMID:20089184

Adsorption methods for hydrogen isotope storage on zeolite sieves

International Nuclear Information System (INIS)

Cristescu, Ioana; Cristescu, Ion; Vasut, Felicia; Brad, Sebastian; Lazar, Alin

2001-01-01

Adsorption molecular sieves and activated carbon were used for hydrogen isotopes. The adsorption process proceeds at liquid nitrogen and liquid hydrogen temperatures. The synthetic zeolites have similar properties as natural zeolites, but they have a regular pore structure and affinity for molecules of different size with defined shapes. Experimental results obtained at liquid nitrogen and liquid hydrogen temperatures evidenced the efficient behavior of the activated carbon and zeolite sieves for hydrogen isotope temporary storage. (authors)

Synthetic biology for pharmaceutical drug discovery

Directory of Open Access Journals (Sweden)

Trosset JY

2015-12-01

Full Text Available Jean-Yves Trosset,1 Pablo Carbonell2,3 1Bioinformation Research Laboratory, Sup’Biotech, Villejuif, France; 2Faculty of Life Sciences, SYNBIOCHEM Centre, Manchester Institute of Biotechnology, University of Manchester, Manchester, UK; 3Department of Experimental and Health Sciences (DCEXS, Research Programme on Biomedical Informatics (GRIB, Hospital del Mar Medical Research Institute (IMIM, Universitat Pompeu Fabra (UPF, Barcelona, Spain Abstract: Synthetic biology (SB is an emerging discipline, which is slowly reorienting the field of drug discovery. For thousands of years, living organisms such as plants were the major source of human medicines. The difficulty in resynthesizing natural products, however, often turned pharmaceutical industries away from this rich source for human medicine. More recently, progress on transformation through genetic manipulation of biosynthetic units in microorganisms has opened the possibility of in-depth exploration of the large chemical space of natural products derivatives. Success of SB in drug synthesis culminated with the bioproduction of artemisinin by microorganisms, a tour de force in protein and metabolic engineering. Today, synthetic cells are not only used as biofactories but also used as cell-based screening platforms for both target-based and phenotypic-based approaches. Engineered genetic circuits in synthetic cells are also used to decipher disease mechanisms or drug mechanism of actions and to study cell–cell communication within bacteria consortia. This review presents latest developments of SB in the field of drug discovery, including some challenging issues such as drug resistance and drug toxicity. Keywords: metabolic engineering, plant synthetic biology, natural products, synthetic quorum sensing, drug resistance

Study of metabolic pathways for hydrogen production in chlamydomonas reinhardtii and transposition on a torus photo bioreactor

International Nuclear Information System (INIS)

Fouchard, S.

2006-04-01

Considering the recent increase in energy consumption. aide associated environmental risks, new trails are followed today to develop the use of clean and renewable alternative energies. In this context hydrogen seems to be a serious solution and this study, based on micro-algae photosynthetic capacities exploitation, will allow to devise a process for hydrogen production from only water and solar energy without greenhouse gas release. The sulphur deprivation protocol on TAP medium, known to lead to hydrogen production in Chlamydomonas reinhardtii species was particularly studied. At the metabolic level, two important phenomena are induced under these conditions: an over-accumulation of the intracellular starch reserves and a simultaneous alteration of the PsII activity which leads to anoxia and Fe-hydrogenase induction, an enzyme with a strong specific activity responsible for the hydrogen production. The contribution of the two electron transfer pathways implied in the hydrogen production process (PsII-dependent and PSII-independent) as well as the importance of the previously accumulated starch were highlighted here. We also investigated the potential for designing autotrophic protocols for hydrogen photoproduction. Various protocols, considered to be relevant, were then transposed on a torus photo-bioreactor, specifically developed in this study and which allows the control of culture parameters as well as the precise measurement of gas release kinetics, in order to obtain first estimates of productivity of the system. Integration of the physical; aspects of the pilot and biological aspects of the process in a model, finally opens new prospects for subject development, in particular for a reasoned optimization of hydrogen production via this double physiology/process approach. (author)

Hydrogen production from cellulose in a two-stage process combining fermentation and electrohydrogenesis

KAUST Repository

Lalaurette, Elodie

2009-08-01

A two-stage dark-fermentation and electrohydrogenesis process was used to convert the recalcitrant lignocellulosic materials into hydrogen gas at high yields and rates. Fermentation using Clostridium thermocellum produced 1.67 mol H2/mol-glucose at a rate of 0.25 L H2/L-d with a corn stover lignocellulose feed, and 1.64 mol H2/mol-glucose and 1.65 L H2/L-d with a cellobiose feed. The lignocelluose and cellobiose fermentation effluent consisted primarily of: acetic, lactic, succinic, and formic acids and ethanol. An additional 800 ± 290 mL H2/g-COD was produced from a synthetic effluent with a wastewater inoculum (fermentation effluent inoculum; FEI) by electrohydrogensis using microbial electrolysis cells (MECs). Hydrogen yields were increased to 980 ± 110 mL H2/g-COD with the synthetic effluent by combining in the inoculum samples from multiple microbial fuel cells (MFCs) each pre-acclimated to a single substrate (single substrate inocula; SSI). Hydrogen yields and production rates with SSI and the actual fermentation effluents were 980 ± 110 mL/g-COD and 1.11 ± 0.13 L/L-d (synthetic); 900 ± 140 mL/g-COD and 0.96 ± 0.16 L/L-d (cellobiose); and 750 ± 180 mL/g-COD and 1.00 ± 0.19 L/L-d (lignocellulose). A maximum hydrogen production rate of 1.11 ± 0.13 L H2/L reactor/d was produced with synthetic effluent. Energy efficiencies based on electricity needed for the MEC using SSI were 270 ± 20% for the synthetic effluent, 230 ± 50% for lignocellulose effluent and 220 ± 30% for the cellobiose effluent. COD removals were ∼90% for the synthetic effluents, and 70-85% based on VFA removal (65% COD removal) with the cellobiose and lignocellulose effluent. The overall hydrogen yield was 9.95 mol-H2/mol-glucose for the cellobiose. These results show that pre-acclimation of MFCs to single substrates improves performance with a complex mixture of substrates, and that high hydrogen yields and gas production rates can be achieved using a two-stage fermentation and MEC

Shell Scotsford's experience with a 100 per cent synthetic crude diet

International Nuclear Information System (INIS)

Margerum, M.

1997-01-01

A qualitative overview of Shell Canada's Scotford refinery was presented. The Scotford refinery is the only refinery in North America designed to run on 100 per cent synthetic crude. As a result, Scotford has a unique configuration and has faced some unique problems. Some of the challenges met in converting synthetic crude to today's products are described. The refinery's unique configuration is centered around a large hydrocracker and has high yield flexibility. The major units of the refinery are the crude unit, hydrocracker, naphtha hydrotreater and reformer, the aromatics complex, the distillate hydrogenator and the hydrogen plants. The refinery products include low sulphur gasoline, jet fuel and diesel fuel. Other products include LPG, FCC feed, benzene and solvents. Several process problems have been experienced at the Scotford refinery including hydrodenitrification of synthetic gasoline, PCA fouling, particulate fouling, crude unit fouling, and distillate lubricity. Solutions have been devised for most of these problems. 3 figs

Gas-to-liquids synthetic fuels for use in fuel cells : reformability, energy density, and infrastructure compatibility.

Energy Technology Data Exchange (ETDEWEB)

Ahmed, S.; Kopasz, J. P.; Russell, B. J.; Tomlinson, H. L.

1999-09-08

The fuel cell has many potential applications, from power sources for electric hybrid vehicles to small power plants for commercial buildings. The choice of fuel will be critical to the pace of its commercialization. This paper reviews the various liquid fuels being considered as an alternative to direct hydrogen gas for the fuel cell application, presents calculations of the hydrogen and carbon dioxide yields from autothermal reforming of candidate liquid fuels, and reports the product gas composition measured from the autothermal reforming of a synthetic fuel in a micro-reactor. The hydrogen yield for a synthetic paraffin fuel produced by a cobalt-based Fischer-Tropsch process was found to be similar to that of retail gasoline. The advantages of the synthetic fuel are that it contains no contaminants that would poison the fuel cell catalyst, is relatively benign to the environment, and could be transported in the existing fuel distribution system.

Solubility of hydrogen in bio-oil compounds

International Nuclear Information System (INIS)

Qureshi, Muhammad Saad; Touronen, Jouni; Uusi-Kyyny, Petri; Richon, Dominique; Alopaeus, Ville

2016-01-01

Highlights: • Solubility of Hydrogen was measured in bio-oil compounds in the at temperatures from 342 to 473 K and pressures up to 16 MPa. • Phase equilibrium data were acquired using a visualization enabled continuous flow synthetic apparatus. • The measured solubility is modeled with Peng-Robinson EoS. - Abstract: The knowledge of accurate hydrogen solubility values in bio-oil compounds is essential for the design and optimization of hydroprocesses relevant to biofuel industry. This work reports the solubility of hydrogen in three industrially relevant bio-oil compounds (allyl alcohol, furan, and eugenol) at temperatures from 342 to 473 K and pressures up to 16 MPa. Phase equilibrium data were acquired using a continuous flow synthetic method. The method is based on the visual observation of the bubble point using a high resolution camera. The measured solubility is modeled with Peng-Robinson EoS with classical van der Waals one fluid mixing rules.

Synthetic biology for microbial production of lipid-based biofuels.

Science.gov (United States)

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

2015-12-01

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

Synthetic biology for microbial production of lipid-based biofuels

Energy Technology Data Exchange (ETDEWEB)

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

2015-10-23

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

Phytoremediation: Potential flora for synthetic dyestuff metabolism

Directory of Open Access Journals (Sweden)

Uruj Tahir

2016-04-01

Full Text Available Dumping of dye-laden effluents into different environmental compartments adversely affects equilibrium and integrity of ecological systems. Being genotoxic, mutagenic and carcinogenic these dyes are quite damaging to health of biota (either aquatic or terrestrial. Many of these dyes are resistant to degradation and remediation under natural conditions and through conventional treatment methods. This situation has necessitated the development of effective and efficient wastewater treatment strategies without further stressing the environment and endangering other life forms. To date many biological systems including microorganisms and plants have been assessed for metabolism of dyestuffs. Phytoremediation catalyzed by natural solar driven pumps (green plants and their associated metabolic processes has emerged as a comparatively new approach and has proven to be one of the most effective environmental friendly strategies for removal, detoxification and decolorization of dyes. Hence, this review quotes the literature of applied aspects of various plant species and their inherent metabolic as well as extractive potentials which enable them to effectively deal with various coloring agents.

Hydrogen energy for beginners

CERN Document Server

2013-01-01

This book highlights the outstanding role of hydrogen in energy processes, where it is the most functional element due to its unique peculiarities that are highlighted and emphasized in the book. The first half of the book covers the great natural hydrogen processes in biology, chemistry, and physics, showing that hydrogen is a trend that can unite all natural sciences. The second half of the book is devoted to the technological hydrogen processes that are under research and development with the aim to create the infrastructure for hydrogen energetics. The book describes the main features of hydrogen that make it inalienable player in processes such as fusion, photosynthesis, and metabolism. It also covers the methods of hydrogen production and storage, highlighting at the same time the exclusive importance of nanotechnologies in those processes.

Device for manufacturing methane or synthetic gas from materials containing carbon using a nuclear reactor

International Nuclear Information System (INIS)

Jaeger, W.

1984-01-01

This invention concerns a device for manufacturing methane or synthetic gas from materials containing carbon using a nuclear reactor, where part of the carbon is gasified with hydration and the remaining carbon is converted to synthetic gas by adding steam. This synthetic gas consists mainly of H 2 , CO, CO 2 and CH 4 and can be converted to methane in so-called methanising using a nickel catalyst. The hydrogen gasifier is situated in the first of two helium circuits of a high temperature reactor, and the splitting furnace is situated in the second helium circuit, where part of the methane produced is split into hydrogen at high temperature, which is used for the hydrating splitting of another part of the material containing carbon. (orig./RB) [de

Development of hydrogen oxidizing bacteria using hydrogen from radiolysis or metal corrosion

International Nuclear Information System (INIS)

Libert, M.F.; Sellier, R.; Marty, V.; Camaro, S.

2000-01-01

The effect of many parameters need to be studied to characterize the long term behavior of nuclear waste in a deep repository. These parameters concern the chemical effects, radiolytic effects, mechanical properties, water composition, and microbiological activity. To evaluate microbial activity in such an environment, work was focused on an inventory of key nutrients (C, H, 0, N, P, S) and energy sources required for bacterial growth. The production of hydrogen in the nuclear waste environment leads to the growth of hydrogen oxidizing bacteria, which modify the gas production balance. A deep repository containing bituminized waste drums implies several sources of hydrogen: - water radiolysis; -corrosion of metal containers; - radiolysis of the embedding matrix (bitumen). Two deep geological disposal conditions leading to H 2 production in a bituminized nuclear waste environment were simulated in the present study: - H 2 production by iron corrosion under anaerobic conditions was simulated by adding 10% of H 2 in the atmosphere; - H 2 production by radiolysis of bitumen matrix was approached by subjecting this material to external gamma irradiation with a dose rate near real conditions (6 Gy/h). The presence of dissolved H 2 in water allows the growth of hydrogen oxidizing bacteria leading to: - CO 2 and N 2 production; - H 2 consumption; - lower NO 3 - concentration caused by reduction to nitrogen. In the first case, hydrogen consumption is limited by the NO 3 - release rate from the bitumen matrix. In the second case, however, under gamma radiation at a low dose rate, hydrogen production is weak, and the hydrogen is completely consumed by microorganisms. Knowledge about these hydrogen oxidizing bacteria is just beginning to emerge. Heterotrophic denitrifying bacteria adapt well to hydrogen metabolism (autotrophic metabolism) by oxidizing H 2 instead of hydrocarbons. (authors)

Hydrogen utilization potential in subsurface sediments

DEFF Research Database (Denmark)

Adhikari, Rishi Ram; Glombitza, Clemens; Nickel, Julia

2016-01-01

Pacific, and Gulf of Mexico) with different predominant electron-acceptors. Hydrogenases constitute a diverse family of enzymes expressed by microorganisms that utilize molecular hydrogen as a metabolic substrate, product, or intermediate. The assay reveals the potential for utilizing molecular hydrogen...

Fusion reactors for hydrogen production via electrolysis

International Nuclear Information System (INIS)

Fillo, J.A.; Powell, J.R.; Steinberg, M.

1979-01-01

The decreasing availability of fossil fuels emphasizes the need to develop systems which will produce synthetic fuel to substitute for and supplement the natural supply. An important first step in the synthesis of liquid and gaseous fuels is the production of hydrogen. Thermonuclear fusion offers an inexhaustible source of energy for the production of hydrogen from water. Depending on design, electric generation efficiencies of approx. 40 to 60% and hydrogen production efficiencies by high temperature electrolysis of approx. 50 to 70% are projected for fusion reactors using high temperature blankets

Electrocatalytic oxidation of hydrogen peroxide on a platinum electrode in the imitation of oxidative drug metabolism of lidocaine.

Science.gov (United States)

Nouri-Nigjeh, Eslam; Bruins, Andries P; Bischoff, Rainer; Permentier, Hjalmar P

2012-10-21

Electrochemistry in combination with mass spectrometry has shown promise as a versatile technique not only in the analytical assessment of oxidative drug metabolism, but also for small-scale synthesis of drug metabolites. However, electrochemistry is generally limited to reactions initiated by direct electron transfer. In the case of substituted-aromatic compounds, oxidation proceeds through a Wheland-type intermediate where resonance stabilization of the positive charge determines the regioselectivity of the anodic substitution reaction, and hence limits the extent of generating drug metabolites in comparison with in vivo oxygen insertion reactions. In this study, we show that the electrocatalytic oxidation of hydrogen peroxide on a platinum electrode generates reactive oxygen species, presumably surface-bound platinum-oxo species, which are capable of oxygen insertion reactions in analogy to oxo-ferryl radical cations in the active site of Cytochrome P450. Electrochemical oxidation of lidocaine at constant potential in the presence of hydrogen peroxide produces both 3- and 4-hydroxylidocaine, suggesting reaction via an arene oxide rather than a Wheland-type intermediate. No benzylic hydroxylation was observed, thus freely diffusing radicals do not appear to be present. The results of the present study extend the possibilities of electrochemical imitation of oxidative drug metabolism to oxygen insertion reactions.

Catalysts for synthetic liquid fuels

Energy Technology Data Exchange (ETDEWEB)

Bruce, L.A.; Turney, T.W.

1987-12-01

Fischer-Tropsch catalysts have been designed, characterized and tested for the selective production of hydrocarbons suitable as synthetic liquid transport fuels from synthesis gas (i.e., by the reduction of carbon monoxide with hydrogen). It was found that hydrocarbons in the middle distillate range, or suitable for conversion to that range, could be produced over several of the new catalyst systems. The various catalysts examined included: (1) synthetic cobalt clays, mainly cobalt chlorites; (2) cobalt hydrotalcites; (3) ruthenium metal supported on rare earth oxides of high surface area; and (4) a novel promoted cobalt catalyst. Active and selective catalysts have been obtained, in each category. With the exception of the clays, reproducibility of catalyst performance has been good. Catalysts in groups 2 and 4 have exhibited very high activity, with long lifetimes and easy regeneration.

Fractionation of hydrogen isotopes by sulfate- and nitrate-reducing bacteria

OpenAIRE

Magdalena Rose Osburn; Katherine S Dawson; Marilyn L Fogel; Alex Sessions

2016-01-01

Hydrogen atoms from water and food are incorporated into biomass during cellular metabolism and biosynthesis, fractionating the isotopes of hydrogen –protium and deuterium –that are recorded in biomolecules. While these fractionations are often relatively constant in plants, large variations in the magnitude of fractionation are observed for many heterotrophic microbes utilizing different central metabolic pathways. The correlation between metabolism and lipid δ2H provides a potential basis f...

Synthetic Biology of Cyanobacteria: Unique Challenges and Opportunities

Directory of Open Access Journals (Sweden)

Bertram M Berla

2013-08-01

Full Text Available Photosynthetic organisms, and especially cyanobacteria, hold great promise as sources of renewably-produced fuels, bulk and specialty chemicals, and nutritional products. Synthetic biology tools can help unlock cyanobacteria’s potential for these functions, but unfortunately tool development for these organisms has lagged behind that for S. cerevisiae and E. coli. While these organisms may in many cases be more difficult to work with as ‘chassis’ strains for synthetic biology than certain heterotrophs, the unique advantages of autotrophs in biotechnology applications as well as the scientific importance of improved understanding of photosynthesis warrant the development of these systems into something akin to a ‘green E. coli’. In this review, we highlight unique challenges and opportunities for development of synthetic biology approaches in cyanobacteria. We review classical and recently developed methods for constructing targeted mutants in various cyanobacterial strains, and offer perspective on what genetic tools might most greatly expand the ability to engineer new functions in such strains. Similarly, we review what genetic parts are most needed for the development of cyanobacterial synthetic biology. Finally, we highlight recent methods to construct genome-scale models of cyanobacterial metabolism and to use those models to measure properties of autotrophic metabolism. Throughout this paper, we discuss some of the unique challenges of a diurnal, autotrophic lifestyle along with how the development of synthetic biology and biotechnology in cyanobacteria must fit within those constraints.

Hydrogen photo-evolution by Rhodopseudomonas palustris 6A using pre-treated olive mill wastewater and a synthetic medium containing sugars

International Nuclear Information System (INIS)

Pintucci, Cristina; Padovani, Giulia; Giovannelli, Alessio; Traversi, Maria Laura; Ena, Alba; Pushparaj, Benjamin; Carlozzi, Pietro

2015-01-01

Highlights: • Adsorbent matrices to convert fresh olive mill wastewater (OMW F ) in feedstock. • Dry-Azolla and granular active carbon for adsorbing polyphenols from OMW F . • Photofermentative processes for biohydrogen production. • Culture mixing by means of an impeller or a magnetic stir bar. • A 30% of dephenolised OMW containing medium suits the photofermentative process. - Abstract: Increasing costs of petroleum, associated with the escalating problems of global climate change, require always greater efforts in order to produce an energy carrier as bioH 2 . In this study, bioH 2 production using photofermentative process was investigated. Two culture broths were used: (a) a synthetic medium rich in sugars (glucose and fructose) and (b) a pre-treated fresh olive-mill wastewater (OMW F ) diluted with water (30%, v:v). The pre-treatment was carried out using two different vegetable matrices (dry-Azolla and granular active carbon) to decrease both the content of polyphenols and the dark colour of wastewater. Rhodopseudomonas palustris 6A isolated from soil spread with OMW was utilized for batch growth experiments, carried out indoors under continuous light (200 μE/m 2 /s). When synthetic medium was used, the culture mixing was performed using either (i) a magnetic stir bar, and (ii) an impeller equipped with five turbines. The latter system made it possible to increase the bioH 2 photo-evolution by 1.4 times. The specific hydrogen photo-evolution rate was 13.5 mL/g(dw)/h in the broth containing diluted OMW F and 11.8 mL/g(dw)/h in the synthetic medium containing sugars (glucose and fructose)

Fractionation of hydrogen isotopes by sulfate- and nitrate-reducing bacteria

Directory of Open Access Journals (Sweden)

Magdalena Rose Osburn

2016-08-01

Full Text Available Hydrogen atoms from water and food are incorporated into biomass during cellular metabolism and biosynthesis, fractionating the isotopes of hydrogen –protium and deuterium –that are recorded in biomolecules. While these fractionations are often relatively constant in plants, large variations in the magnitude of fractionation are observed for many heterotrophic microbes utilizing different central metabolic pathways. The correlation between metabolism and lipid δ2H provides a potential basis for reconstructing environmental and ecological parameters, but the calibration dataset has thus far been limited mainly to aerobes. Here we report on the hydrogen isotopic fractionations of lipids produced by nitrate-respiring and sulfate-reducing bacteria. We observe only small differences in fractionation between oxygen- and nitrate-respiring growth conditions, with a typical pattern of variation between substrates that is broadly consistent with previously described trends. In contrast, fractionation by sulfate-reducing bacteria does not vary significantly between different substrates, even when autotrophic and heterotrophic growth conditions are compared. This result is in marked contrast to previously published observations and has significant implications for the interpretation of environmental hydrogen isotope data. We evaluate these trends in light of metabolic gene content of each strain, growth rate, and potential flux and reservoir-size effects of cellular hydrogen, but find no single variable that can account for the differences between nitrate- and sulfate-respiring bacteria. The emerging picture of bacterial hydrogen isotope fractionation is therefore more complex than the simple correspondence between δ2H and metabolic pathway previously understood from aerobes. Despite the complexity, the large signals and rich variability of observed lipid δ2H suggest much potential as an environmental recorder of metabolism.

Fractionation of Hydrogen Isotopes by Sulfate- and Nitrate-Reducing Bacteria.

Science.gov (United States)

Osburn, Magdalena R; Dawson, Katherine S; Fogel, Marilyn L; Sessions, Alex L

2016-01-01

Hydrogen atoms from water and food are incorporated into biomass during cellular metabolism and biosynthesis, fractionating the isotopes of hydrogen-protium and deuterium-that are recorded in biomolecules. While these fractionations are often relatively constant in plants, large variations in the magnitude of fractionation are observed for many heterotrophic microbes utilizing different central metabolic pathways. The correlation between metabolism and lipid δ(2)H provides a potential basis for reconstructing environmental and ecological parameters, but the calibration dataset has thus far been limited mainly to aerobes. Here we report on the hydrogen isotopic fractionations of lipids produced by nitrate-respiring and sulfate-reducing bacteria. We observe only small differences in fractionation between oxygen- and nitrate-respiring growth conditions, with a typical pattern of variation between substrates that is broadly consistent with previously described trends. In contrast, fractionation by sulfate-reducing bacteria does not vary significantly between different substrates, even when autotrophic and heterotrophic growth conditions are compared. This result is in marked contrast to previously published observations and has significant implications for the interpretation of environmental hydrogen isotope data. We evaluate these trends in light of metabolic gene content of each strain, growth rate, and potential flux and reservoir-size effects of cellular hydrogen, but find no single variable that can account for the differences between nitrate- and sulfate-respiring bacteria. The emerging picture of bacterial hydrogen isotope fractionation is therefore more complex than the simple correspondence between δ(2)H and metabolic pathway previously understood from aerobes. Despite the complexity, the large signals and rich variability of observed lipid δ(2)H suggest much potential as an environmental recorder of metabolism.

Physical, chemical, and metabolic state sensors expand the synthetic biology toolbox for Synechocystis sp. PCC 6803.

Science.gov (United States)

Immethun, Cheryl M; DeLorenzo, Drew M; Focht, Caroline M; Gupta, Dinesh; Johnson, Charles B; Moon, Tae Seok

2017-07-01

Many under-developed organisms possess important traits that can boost the effectiveness and sustainability of microbial biotechnology. Photoautotrophic cyanobacteria can utilize the energy captured from light to fix carbon dioxide for their metabolic needs while living in environments not suited for growing crops. Various value-added compounds have been produced by cyanobacteria in the laboratory; yet, the products' titers and yields are often not industrially relevant and lag behind what have been accomplished in heterotrophic microbes. Genetic tools for biological process control are needed to take advantage of cyanobacteria's beneficial qualities, as tool development also lags behind what has been created in common heterotrophic hosts. To address this problem, we developed a suite of sensors that regulate transcription in the model cyanobacterium Synechocystis sp. PCC 6803 in response to metabolically relevant signals, including light and the cell's nitrogen status, and a family of sensors that respond to the inexpensive chemical, l-arabinose. Increasing the number of available tools enables more complex and precise control of gene expression. Expanding the synthetic biology toolbox for this cyanobacterium also improves our ability to utilize this important under-developed organism in biotechnology. Biotechnol. Bioeng. 2017;114: 1561-1569. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Advanced water splitting for green hydrogen gas production through complete oxidation of starch by in vitro metabolic engineering.

Science.gov (United States)

Kim, Jae-Eung; Kim, Eui-Jin; Chen, Hui; Wu, Chang-Hao; Adams, Michael W W; Zhang, Y-H Percival

2017-11-01

Starch is a natural energy storage compound and is hypothesized to be a high-energy density chemical compound or solar fuel. In contrast to industrial hydrolysis of starch to glucose, an alternative ATP-free phosphorylation of starch was designed to generate cost-effective glucose 6-phosphate by using five thermophilic enzymes (i.e., isoamylase, alpha-glucan phosphorylase, 4-α-glucanotransferase, phosphoglucomutase, and polyphosphate glucokinase). This enzymatic phosphorolysis is energetically advantageous because the energy of α-1,4-glycosidic bonds among anhydroglucose units is conserved in the form of phosphorylated glucose. Furthermore, we demonstrated an in vitro 17-thermophilic enzyme pathway that can convert all glucose units of starch, regardless of branched and linear contents, with water to hydrogen at a theoretic yield (i.e., 12 H 2 per glucose), three times of the theoretical yield from dark microbial fermentation. The use of a biomimetic electron transport chain enabled to achieve a maximum volumetric productivity of 90.2mmol of H 2 /L/h at 20g/L starch. The complete oxidation of starch to hydrogen by this in vitro synthetic (enzymatic) biosystem suggests that starch as a natural solar fuel becomes a high-density hydrogen storage compound with a gravimetric density of more than 14% H 2 -based mass and an electricity density of more than 3000Wh/kg of starch. Copyright © 2017. Published by Elsevier Inc.

Synfuel (hydrogen) production from fusion power

International Nuclear Information System (INIS)

Krakowski, R.A.; Cox, K.E.; Pendergrass, J.H.; Booth, L.A.

1979-01-01

A potential use of fusion energy for the production of synthetic fuel (hydrogen) is described. The hybrid-thermochemical bismuth-sulfate cycle is used as a vehicle to assess the technological and economic merits of this potential nonelectric application of fusion power

SBOLme: a Repository of SBOL Parts for Metabolic Engineering

KAUST Repository

Kuwahara, Hiroyuki

2017-01-12

The Synthetic Biology Open Language (SBOL) is a community-driven open language to promote standardization in synthetic biology. To support the use of SBOL in metabolic engineering, we developed SBOLme, the first open-access repository of SBOL 2-compliant biochemical parts for a wide range of metabolic engineering applications. The URL of our repository is http://www.cbrc.kaust.edu.sa/sbolme.

DNA-inspired hierarchical polymer design: electrostatics and hydrogen bonding in concert.

Science.gov (United States)

Hemp, Sean T; Long, Timothy E

2012-01-01

Nucleic acids and proteins, two of nature's biopolymers, assemble into complex structures to achieve desired biological functions and inspire the design of synthetic macromolecules containing a wide variety of noncovalent interactions including electrostatics and hydrogen bonding. Researchers have incorporated DNA nucleobases into a wide variety of synthetic monomers/polymers achieving stimuli-responsive materials, supramolecular assemblies, and well-controlled macromolecules. Recently, scientists utilized both electrostatics and complementary hydrogen bonding to orthogonally functionalize a polymer backbone through supramolecular assembly. Diverse macromolecules with noncovalent interactions will create materials with properties necessary for biomedical applications. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Effects of Synthetic Cannabinoids on Alveolar-Arterial Oxygen Gradient

Directory of Open Access Journals (Sweden)

Egemen Kucuk

2016-09-01

Full Text Available Aim: Synthetic cannabinoids are chemicals that produce several marijuana-like effects in humans. Aim of this study is to investigate the effects of synthetic cannabinoids on to alveolar-arterial oxygen gradient. Material and Method: A total of 112 patients, who admitted directly to emergency clinic with synthetic cannabinoid usage, were determined between February 2014 and August 2014. Blood gases of 41 patients were determined as arterial blood gases on room air, and included in to study. Patients were evaluated according to age, sex, decade, partial pressure of arterial oxygen, partial pressure of arterial carbon dioxide, pH, bicarbonate, metabolic status, age consistent expected alveolar-arterial oxygen gradient and calculated alveolar-arterial oxygen gradient. Results: Synthetic cannabinoid using was higher in males, mean age of patients was 23.32±6.14 years. Number of patients in the third decade were significantly higher than the other decades. The calculated alveolar-arterial oxygen gradient value of patients was significantly higher than age consistent expected alveolar-arterial oxygen gradient value. Respiratory acidosis, was significantly higher than the other types of the metabolic disorders. The best cutoff point for calculated alveolar-arterial oxygen gradient was 12.70, with sensitivity of 90% and specifity of 85%. Area under curve was 0.70 for calculated alveolar-arterial oxygen gradient. Discussion: The value of alveolar-arterial oxygen gradient has been increased due to synthetic cannabinoid usage. This can be used as a supportive parameter in the diagnosis of synthetic cannabinoid usage.

The logics of metabolic regulation in bacteria challenges biosensor-based metabolic engineering

Directory of Open Access Journals (Sweden)

Matthieu Jules

2017-12-01

Full Text Available Synthetic Biology (SB aims at the rational design and engineering of novel biological functions and systems. By facilitating the engineering of living organisms, SB promises to facilitate the development of many new applications for health, biomanufacturing, and the environment. Over the last decade, SB promoted the construction of libraries of components enabling the fine-tuning of genetic circuits expression and the development of novel genome engineering methodologies for many organisms of interest. SB thus opened new perspectives in the field of metabolic engineering, which was until then mainly limited to (overproducing naturally synthesized metabolic compounds. To engineer efficient cell factories, it is key to precisely reroute cellular resources from the central carbon metabolism (CCM to the synthetic circuitry. This task is however difficult as there is still significant lack of knowledge regarding both the function of several metabolic components and the regulation of the CCM fluxes for many industrially important bacteria. Pyruvate is a pivotal metabolite at the heart of the CCM and a key precursor for the synthesis of several commodity compounds and fine chemicals. Numerous bacterial species can also use it as a carbon source when present in the environment but bacterial, pyruvate-specific uptake systems were to be discovered. This is an issue for metabolic engineering as one can imagine to make use of pyruvate transport systems to replenish synthetic metabolic pathways towards the synthesis of chemicals of interest. Here we describe a recent study (MBio 8(5: e00976-17, which identified and characterized a pyruvate transport system in the Gram-positive (G+ve bacterium Bacillus subtilis, a well-established biotechnological workhorse for the production of enzymes, fine chemicals and antibiotics. This study also revealed that the activity of the two-component system (TCS responsible for its induction is retro-inhibited by the level of

Synthetic neurosteroids on brain protection

Directory of Open Access Journals (Sweden)

Mariana Rey

2015-01-01

Full Text Available Neurosteroids, like allopregnanolone and pregnanolone, are endogenous regulators of neuronal excitability. Inside the brain, they are highly selective and potent modulators of GABA A receptor activity. Their anticonvulsant, anesthetics and anxiolytic properties are useful for the treatments of several neurological and psychiatric disorders via reducing the risks of side effects obtained with the commercial drugs. The principal disadvantages of endogenous neurosteroids administration are their rapid metabolism and their low oral bioavailability. Synthetic steroids analogues with major stability or endogenous neurosteroids stimulation synthesis might constitute promising novel strategies for the treatment of several disorders. Numerous studies indicate that the 3α-hydroxyl configuration is the key for binding and activity, but modifications in the steroid nucleus may emphasize different pharmacophores. So far, several synthetic steroids have been developed with successful neurosteroid-like effects. In this work, we summarize the properties of various synthetic steroids probed in trials throughout the analysis of several neurosteroids-like actions.

Chemical constraints governing the origin of metabolism: the thermodynamic landscape of carbon group transformations under mild aqueous conditions

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Weber, Arthur L.

2002-01-01

The thermodynamics of organic chemistry under mild aqueous conditions was examined in order to begin to understand its influence on the structure and operation of metabolism and its antecedents. Free energies (deltaG) were estimated for four types of reactions of biochemical importance carbon-carbon bond cleavage and synthesis, hydrogen transfer between carbon groups, dehydration of alcohol groups, and aldo-keto isomerization. The energies were calculated for mainly aliphatic groups composed of carbon, hydrogen, and oxygen. The energy values showed (1) that generally when carbon-carbon bond cleavage involves groups from different functional group classes (i.e., carboxylic acids, carbonyl groups, alcohols, and hydrocarbons), the transfer of the shared electron-pair to the more reduced carbon group is energetically favored over transfer to the more oxidized carbon group, and (2) that the energy of carbon-carbon bond transformation is primarily determined by the functional group class of the group that changes oxidation state in the reaction (i.e., the functional group class of the group that donates the shared electron-pair during cleavage, or that accepts the incipient shared electron-pair during synthesis). In contrast, the energy of hydrogen transfer between carbon groups is determined by the functional group class of both the hydrogen-donor group and the hydrogen-acceptor group. From these and other observations we concluded that the chemistry involved in the origin of metabolism (and to a lesser degree modern metabolism) was strongly constrained by (1) the limited redox-based transformation energy of organic substrates that is readily dissipated in a few energetically favorable irreversible reactions; (2) the energy dominance of a few transformation half-reactions that determines whether carbon-carbon bond transformation (cleavage or synthesis) is energetically favorable (deltaG +3.5 kcal/mol); and (3) the dependence of carbon group transformation energy on the

Synthetic Botany.

Science.gov (United States)

Boehm, Christian R; Pollak, Bernardo; Purswani, Nuri; Patron, Nicola; Haseloff, Jim

2017-07-05

Plants are attractive platforms for synthetic biology and metabolic engineering. Plants' modular and plastic body plans, capacity for photosynthesis, extensive secondary metabolism, and agronomic systems for large-scale production make them ideal targets for genetic reprogramming. However, efforts in this area have been constrained by slow growth, long life cycles, the requirement for specialized facilities, a paucity of efficient tools for genetic manipulation, and the complexity of multicellularity. There is a need for better experimental and theoretical frameworks to understand the way genetic networks, cellular populations, and tissue-wide physical processes interact at different scales. We highlight new approaches to the DNA-based manipulation of plants and the use of advanced quantitative imaging techniques in simple plant models such as Marchantia polymorpha. These offer the prospects of improved understanding of plant dynamics and new approaches to rational engineering of plant traits. Copyright © 2017 Cold Spring Harbor Laboratory Press; all rights reserved.

Modular design of synthetic protein mimics. Characterization of the helical conformation of a 13-residue peptide in crystals

International Nuclear Information System (INIS)

Karle, I.L.; Flippen-Anderson, J.L.; Uma, K.; Balaram, P.

1989-01-01

The incorporation of α-aminoisobutyryl (Aib) residues into peptide sequences facilitates helical folding. Aib-containing sequences have been chosen for the design of rigid helical segments in a modular approach to the construction of a synthetic protein mimic. The helical conformation of the synthetic peptide Boc-Aib-(Val-Ala-Leu-Aib) 3 -OMe in crystals is established by X-ray diffraction. The 13-residue apolar peptide adopts a helical form in the crystal with seven α-type hydrogen bonds in the middle and 3 10 -type hydrogen bonds at either end. The helices stack in columns, zigzag rather than linear, by means of direct NH hor-ellipsis OC head to tail hydrogen bonds. Leucyl side chains are extended on one side of the helix and valyl side chains on the other side. Water molecules form hydrogen bonds with several backbone carbonyl oxygens that also participate in α-helix hydrogen bonds. There is no apparent distortion of the helix caused by hydration

Synthetic biology as it relates to CAM photosynthesis: challenges and opportunities.

Science.gov (United States)

DePaoli, Henrique C; Borland, Anne M; Tuskan, Gerald A; Cushman, John C; Yang, Xiaohan

2014-07-01

To meet future food and energy security needs, which are amplified by increasing population growth and reduced natural resource availability, metabolic engineering efforts have moved from manipulating single genes/proteins to introducing multiple genes and novel pathways to improve photosynthetic efficiency in a more comprehensive manner. Biochemical carbon-concentrating mechanisms such as crassulacean acid metabolism (CAM), which improves photosynthetic, water-use, and possibly nutrient-use efficiency, represent a strategic target for synthetic biology to engineer more productive C3 crops for a warmer and drier world. One key challenge for introducing multigene traits like CAM onto a background of C3 photosynthesis is to gain a better understanding of the dynamic spatial and temporal regulatory events that underpin photosynthetic metabolism. With the aid of systems and computational biology, vast amounts of experimental data encompassing transcriptomics, proteomics, and metabolomics can be related in a network to create dynamic models. Such models can undergo simulations to discover key regulatory elements in metabolism and suggest strategic substitution or augmentation by synthetic components to improve photosynthetic performance and water-use efficiency in C3 crops. Another key challenge in the application of synthetic biology to photosynthesis research is to develop efficient systems for multigene assembly and stacking. Here, we review recent progress in computational modelling as applied to plant photosynthesis, with attention to the requirements for CAM, and recent advances in synthetic biology tool development. Lastly, we discuss possible options for multigene pathway construction in plants with an emphasis on CAM-into-C3 engineering. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Fusion: an energy source for synthetic fuels

International Nuclear Information System (INIS)

Fillo, J.A.; Powell, J; Steinberg, M.

1980-01-01

The decreasing availability of fossil fuels emphasizes the need to develop systems which will produce synthetic fuel to substitute for and supplement the natural supply. An important first step in the synthesis of liquid and gaseous fuels is the production of hydrogen. Thermonuclear fusion offers an inexhaustible source of energy for the production of hydrogen from water. Depending on design, electric generation efficiencies of approx. 40 to 60% and hydrogen production efficiencies by high temperature electrolysis of approx. 50 to 70% are projected for fusion reactors using high temperature blankets. Fusion/coal symbiotic systems appear economically promising for the first generation of commercial fusion synfuels plants. Coal production requirements and the environmental effects of large-scale coal usage would be greatly reduced by a fusion/coal system. In the long term, there could be a gradual transition to an inexhaustible energy system based solely on fusion

Synergistic Synthetic Biology: Units in Concert

Science.gov (United States)

Trosset, Jean-Yves; Carbonell, Pablo

2013-01-01

Synthetic biology aims at translating the methods and strategies from engineering into biology in order to streamline the design and construction of biological devices through standardized parts. Modular synthetic biology devices are designed by means of an adequate elimination of cross-talk that makes circuits orthogonal and specific. To that end, synthetic constructs need to be adequately optimized through in silico modeling by choosing the right complement of genetic parts and by experimental tuning through directed evolution and craftsmanship. In this review, we consider an additional and complementary tool available to the synthetic biologist for innovative design and successful construction of desired circuit functionalities: biological synergies. Synergy is a prevalent emergent property in biological systems that arises from the concerted action of multiple factors producing an amplification or cancelation effect compared with individual actions alone. Synergies appear in domains as diverse as those involved in chemical and protein activity, polypharmacology, and metabolic pathway complementarity. In conventional synthetic biology designs, synergistic cross-talk between parts and modules is generally attenuated in order to verify their orthogonality. Synergistic interactions, however, can induce emergent behavior that might prove useful for synthetic biology applications, like in functional circuit design, multi-drug treatment, or in sensing and delivery devices. Synergistic design principles are therefore complementary to those coming from orthogonal design and may provide added value to synthetic biology applications. The appropriate modeling, characterization, and design of synergies between biological parts and units will allow the discovery of yet unforeseeable, novel synthetic biology applications. PMID:25022769

Synergistic Synthetic Biology: Units in Concert

International Nuclear Information System (INIS)

Trosset, Jean-Yves; Carbonell, Pablo

2013-01-01

Synthetic biology aims at translating the methods and strategies from engineering into biology in order to streamline the design and construction of biological devices through standardized parts. Modular synthetic biology devices are designed by means of an adequate elimination of cross-talk that makes circuits orthogonal and specific. To that end, synthetic constructs need to be adequately optimized through in silico modeling by choosing the right complement of genetic parts and by experimental tuning through directed evolution and craftsmanship. In this review, we consider an additional and complementary tool available to the synthetic biologist for innovative design and successful construction of desired circuit functionalities: biological synergies. Synergy is a prevalent emergent property in biological systems that arises from the concerted action of multiple factors producing an amplification or cancelation effect compared with individual actions alone. Synergies appear in domains as diverse as those involved in chemical and protein activity, polypharmacology, and metabolic pathway complementarity. In conventional synthetic biology designs, synergistic cross-talk between parts and modules is generally attenuated in order to verify their orthogonality. Synergistic interactions, however, can induce emergent behavior that might prove useful for synthetic biology applications, like in functional circuit design, multi-drug treatment, or in sensing and delivery devices. Synergistic design principles are therefore complementary to those coming from orthogonal design and may provide added value to synthetic biology applications. The appropriate modeling, characterization, and design of synergies between biological parts and units will allow the discovery of yet unforeseeable, novel synthetic biology applications.

Genetics and Molecular Biology of Hydrogen Metabolism in Sulfate-Reducing Bacteria

Energy Technology Data Exchange (ETDEWEB)

Wall, Judy D. [Univ. of Missouri, Columbia, MO (United States)

2014-12-23

The degradation of our environment and the depletion of fossil fuels make the exploration of alternative fuels evermore imperative. Among the alternatives is biohydrogen which has high energy content by weight and produces only water when combusted. Considerable effort is being expended to develop photosynthetic systems -- algae, cyanobacteria, and anaerobic phototrophs -- for sustainable H₂ production. While promising, this approach also has hurdles such as the harvesting of light in densely pigmented cultures that requires costly constant mixing and large areas for exposure to sunlight. Little attention is given to fermentative H₂ generation. Thus understanding the microbial pathways to H₂ evolution and metabolic processes competing for electrons is an essential foundation that may expand the variety of fuels that can be generated or provide alternative substrates for fine chemical production. We studied a widely found soil anaerobe of the class Deltaproteobacteria, a sulfate-reducing bacterium to determine the electron pathways used during the oxidation of substrates and the potential for hydrogen production.

Hydrogen isotopic messages in sulfate reducer lipids: a recorder of metabolic state?

Science.gov (United States)

Bradley, A. S.; Leavitt, W.; Zhou, A.; Cobban, A.; Suess, M.

2017-12-01

A significant range in microbial lipid 2H/1H ratios is observed in modern marine sediments. The magnitude of hydrogen isotope fractionation between microbial lipids and growth water (2ɛlipid-H2O) is hypothesized to relate to the central carbon and energy metabolism. These observations raise the possibility for culture independent identification of the dominant metabolic pathways operating in a given environment [Zhang et al. 2009]. One such metabolism we aim to track is microbial sulfate reduction. To-date, sulfate reducing bacteria have been observed to produce lipids that are depleted in fatty acid H-isotope composition, relative to growth water (2ɛlipid-H2O -50 to -175 ‰) [Campbell et al. 2009; Dawson et al. 2015; Osburn et al.], with recent work demonstrating a systematic relationship between lipid/water fractionation and growth rate when the electron-bifurcating NAD(P)(H) transhydrogenase (ebTH) activity was disrupted and the available electron requires the ebTH [Leavitt et al. 2016. Front Microbio]. Recent work in aerobic methylotrophs [Bradley et al. 2014. AGU] implicates non-bifurcating NAD(P)(H) transhydrogenase activity is a critical control on 2ɛlipid-H2O. This suggests a specific mechanism to control the range in fractionation is the ratio of intracellular NADPH/NADH/NADP/NAD in aerobes and perhaps the same in anaerobes with some consideration for FADH/FAD. Fundamentally this implies 2ɛlipid-H2O records intracellular redox state. In our sulfate reducer model system Desulfovibrio alaskensis strain G20 a key component of energy metabolism is the activity of ebTH. Nonetheless, this strain contains two independent copies of the genes, only one of which generates a distinctive isotopic phenotype [Leavitt et al. 2016. Front Microbio]. In this study we extend the recent work in G20 to continuous culture experiments comparing WT to nfnAB-2 transposon interruptions, where both organisms are cultivated continuously, at the rate of the slower growing mutant

Osseointegration of dental implants in 3D-printed synthetic onlay grafts customized according to bone metabolic activity in recipient site.

Science.gov (United States)

Tamimi, Faleh; Torres, Jesus; Al-Abedalla, Khadijeh; Lopez-Cabarcos, Enrique; Alkhraisat, Mohammad H; Bassett, David C; Gbureck, Uwe; Barralet, Jake E

2014-07-01

Onlay grafts made of monolithic microporous monetite bioresorbable bioceramics have the capacity to conduct bone augmentation. However, there is heterogeneity in the graft behaviour in vivo that seems to correlate with the host anatomy. In this study, we sought to investigate the metabolic activity of the regenerated bone in monolithic monetite onlays by using positron emission tomography-computed tomography (PET-CT) in rats. This information was used to optimize the design of monetite onlays with different macroporous architecture that were then fabricated using a 3D-printing technique. In vivo, bone augmentation was attempted with these customized onlays in rabbits. PET-CT findings demonstrated that bone metabolism in the calvarial bone showed higher activity in the inferior and lateral areas of the onlays. Histological observations revealed higher bone volume (up to 47%), less heterogeneity and more implant osseointegration (up to 38%) in the augmented bone with the customized monetite onlays. Our results demonstrated for the first time that it is possible to achieve osseointegration of dental implants in bone augmented with 3D-printed synthetic onlays. It was also observed that designing the macropore geometry according to the bone metabolic activity was a key parameter in increasing the volume of bone augmented within monetite onlays. Copyright © 2014 Elsevier Ltd. All rights reserved.

High-yield hydrogen production from biomass by in vitro metabolic engineering: Mixed sugars coutilization and kinetic modeling

Science.gov (United States)

Rollin, Joseph A.; Martin del Campo, Julia; Myung, Suwan; Sun, Fangfang; You, Chun; Bakovic, Allison; Castro, Roberto; Chandrayan, Sanjeev K.; Wu, Chang-Hao; Adams, Michael W. W.; Senger, Ryan S.; Zhang, Y.-H. Percival

2015-01-01

The use of hydrogen (H2) as a fuel offers enhanced energy conversion efficiency and tremendous potential to decrease greenhouse gas emissions, but producing it in a distributed, carbon-neutral, low-cost manner requires new technologies. Herein we demonstrate the complete conversion of glucose and xylose from plant biomass to H2 and CO2 based on an in vitro synthetic enzymatic pathway. Glucose and xylose were simultaneously converted to H2 with a yield of two H2 per carbon, the maximum possible yield. Parameters of a nonlinear kinetic model were fitted with experimental data using a genetic algorithm, and a global sensitivity analysis was used to identify the enzymes that have the greatest impact on reaction rate and yield. After optimizing enzyme loadings using this model, volumetric H2 productivity was increased 3-fold to 32 mmol H2⋅L−1⋅h−1. The productivity was further enhanced to 54 mmol H2⋅L−1⋅h−1 by increasing reaction temperature, substrate, and enzyme concentrations—an increase of 67-fold compared with the initial studies using this method. The production of hydrogen from locally produced biomass is a promising means to achieve global green energy production. PMID:25848015

High-yield hydrogen production from biomass by in vitro metabolic engineering: Mixed sugars coutilization and kinetic modeling.

Science.gov (United States)

Rollin, Joseph A; Martin del Campo, Julia; Myung, Suwan; Sun, Fangfang; You, Chun; Bakovic, Allison; Castro, Roberto; Chandrayan, Sanjeev K; Wu, Chang-Hao; Adams, Michael W W; Senger, Ryan S; Zhang, Y-H Percival

2015-04-21

The use of hydrogen (H2) as a fuel offers enhanced energy conversion efficiency and tremendous potential to decrease greenhouse gas emissions, but producing it in a distributed, carbon-neutral, low-cost manner requires new technologies. Herein we demonstrate the complete conversion of glucose and xylose from plant biomass to H2 and CO2 based on an in vitro synthetic enzymatic pathway. Glucose and xylose were simultaneously converted to H2 with a yield of two H2 per carbon, the maximum possible yield. Parameters of a nonlinear kinetic model were fitted with experimental data using a genetic algorithm, and a global sensitivity analysis was used to identify the enzymes that have the greatest impact on reaction rate and yield. After optimizing enzyme loadings using this model, volumetric H2 productivity was increased 3-fold to 32 mmol H2⋅L(-1)⋅h(-1). The productivity was further enhanced to 54 mmol H2⋅L(-1)⋅h(-1) by increasing reaction temperature, substrate, and enzyme concentrations--an increase of 67-fold compared with the initial studies using this method. The production of hydrogen from locally produced biomass is a promising means to achieve global green energy production.

Storing Renewable Energy in the Hydrogen Cycle.

Science.gov (United States)

Züttel, Andreas; Callini, Elsa; Kato, Shunsuke; Atakli, Züleyha Özlem Kocabas

2015-01-01

An energy economy based on renewable energy requires massive energy storage, approx. half of the annual energy consumption. Therefore, the production of a synthetic energy carrier, e.g. hydrogen, is necessary. The hydrogen cycle, i.e. production of hydrogen from water by renewable energy, storage and use of hydrogen in fuel cells, combustion engines or turbines is a closed cycle. Electrolysis splits water into hydrogen and oxygen and represents a mature technology in the power range up to 100 kW. However, the major technological challenge is to build electrolyzers in the power range of several MW producing high purity hydrogen with a high efficiency. After the production of hydrogen, large scale and safe hydrogen storage is required. Hydrogen is stored either as a molecule or as an atom in the case of hydrides. The maximum volumetric hydrogen density of a molecular hydrogen storage is limited to the density of liquid hydrogen. In a complex hydride the hydrogen density is limited to 20 mass% and 150 kg/m(3) which corresponds to twice the density of liquid hydrogen. Current research focuses on the investigation of new storage materials based on combinations of complex hydrides with amides and the understanding of the hydrogen sorption mechanism in order to better control the reaction for the hydrogen storage applications.

Pathway of Fermentative Hydrogen Production by Sulfate-reducing Bacteria

Energy Technology Data Exchange (ETDEWEB)

Wall, Judy D. [Univ. of Missouri, Columbia, MO (United States)

2015-02-16

Biofuels are a promising source of sustainable energy. Such biofuels are intermediate products of microbial metabolism of renewable substrates, in particular, plant biomass. Not only are alcohols and solvents produced in this degradative process but energy-rich hydrogen as well. Non photosynthetic microbial hydrogen generation from compounds other than sugars has not been fully explored. We propose to examine the capacity of the abundant soil anaerobes, sulfate-reducing bacteria, for hydrogen generation from organic acids. These apparently simple pathways have yet to be clearly established. Information obtained may facilitate the exploitation of other microbes not yet readily examined by molecular tools. Identification of the flexibility of the metabolic processes to channel reductant to hydrogen will be useful in consideration of practical applications. Because the tools for genetic and molecular manipulation of sulfate-reducing bacteria of the genus Desulfovibrio are developed, our efforts will focus on two strains, D. vulgaris Hildenborough and Desulfovibrio G20.Therefore total metabolism, flux through the pathways, and regulation are likely to be limiting factors which we can elucidate in the following experiments.

Hydrogen alternatives for a regional upgrader

International Nuclear Information System (INIS)

Bailey, R.T.; Padamsey, R.

1991-01-01

For a proposed regional upgrader in Alberta, hydrogen will be needed to upgrade the bitumen and heavy oil to be processed by that facility. The upgrader will rely on high conversion hydrocracking which consumes 3.4 wt % hydrogen to produce a 106% volume yield of high quality synthetic crude. The costs of producing hydrogen via steam reforming of methane, partial oxidation of coal or upgrading residues, and electrolysis are compared, showing that steam reforming is the cheapest. However, an even cheaper source of hydrogen is available in the Edmonton and Fort Saskatchewan area as byproducts from petrochemical plants. An economic analysis is presented of a proposed scheme to capture, purify, compress, and transfer hydrogen from one or two such plants to a nearby regional upgrader. The two plants could supply a total of 126.6 million ft 3 /d of hydrogen at a total installed capital cost of about half of that of a steam reforming plant of equivalent size. When operating costs are added (including the cost of replacing the hydrogen, currently used as fuel at the two plants, with natural gas), the total cost of hydrogen is substantially less than the costs for a hydrogen plant within the upgrader. 3 refs., 5 figs., 4 tabs

A green synthetic approach to graphene nanosheets for hydrogen adsorption

International Nuclear Information System (INIS)

Yuan Wenhui; Li Baoqing; Li Li

2011-01-01

A green and facile strategy of preparing graphene by reducing exfoliated graphite oxide (GO) with glucose was developed in this study. The as-prepared samples were characterized by X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and Atomic force microscopy (AFM). The characterization results indicated that the graphene sheets (GS) were of high quality with smooth surface, rich pore structure and few layer graphene. The samples have a BET specific surface area of 1205.8 m 2 g -1 measured by N 2 adsorption at 77 K. The hydrogen storage capacity of 2.7 wt.% at 298 K and 25 bar demonstrated that the as-prepared graphene employing glucose as reductant is supposed to be a promising material with outstanding property for hydrogen storage.

Improvements in Fermentative Biological Hydrogen Production Through Metabolic Engineering

Energy Technology Data Exchange (ETDEWEB)

Hallenbeck, P. C.; Ghosh, D.; Sabourin-Provost, G.

2009-07-01

Dramatically rising oil prices and increasing awareness of the dire environmental consequences of fossil fuel use, including startling effects of climate change, are refocusing attention world-wide on the search for alternative fuels. Hydrogen is poised to become an important future energy carrier. Renewable hydrogen production is pivotal in making it a truly sustainable replacement for fossil fuels. (Author)

Improvements in Fermentative Biological Hydrogen Production Through Metabolic Engineering

International Nuclear Information System (INIS)

Hallenbeck, P. C.; Ghosh, D.; Sabourin-Provost, G.

2009-01-01

Dramatically rising oil prices and increasing awareness of the dire environmental consequences of fossil fuel use, including startling effects of climate change, are refocusing attention world-wide on the search for alternative fuels. Hydrogen is poised to become an important future energy carrier. Renewable hydrogen production is pivotal in making it a truly sustainable replacement for fossil fuels. (Author)

Hydrogen production by recombinant Escherichia coli strains

Science.gov (United States)

Maeda, Toshinari; Sanchez‐Torres, Viviana; Wood, Thomas K.

2012-01-01

Summary The production of hydrogen via microbial biotechnology is an active field of research. Given its ease of manipulation, the best‐studied bacterium Escherichia coli has become a workhorse for enhanced hydrogen production through metabolic engineering, heterologous gene expression, adaptive evolution, and protein engineering. Herein, the utility of E. coli strains to produce hydrogen, via native hydrogenases or heterologous ones, is reviewed. In addition, potential strategies for increasing hydrogen production are outlined and whole‐cell systems and cell‐free systems are compared. PMID:21895995

Prediction of novel synthetic pathways for the production of desired chemicals

Directory of Open Access Journals (Sweden)

Park Jin

2010-03-01

Full Text Available Abstract Background There have been several methods developed for the prediction of synthetic metabolic pathways leading to the production of desired chemicals. In these approaches, novel pathways were predicted based on chemical structure changes, enzymatic information, and/or reaction mechanisms, but the approaches generating a huge number of predicted results are difficult to be applied to real experiments. Also, some of these methods focus on specific pathways, and thus are limited to expansion to the whole metabolism. Results In the present study, we propose a system framework employing a retrosynthesis model with a prioritization scoring algorithm. This new strategy allows deducing the novel promising pathways for the synthesis of a desired chemical together with information on enzymes involved based on structural changes and reaction mechanisms present in the system database. The prioritization scoring algorithm employing Tanimoto coefficient and group contribution method allows examination of structurally qualified pathways to recognize which pathway is more appropriate. In addition, new concepts of binding site covalence, estimation of pathway distance and organism specificity were taken into account to identify the best synthetic pathway. Parameters of these factors can be evolutionarily optimized when a newly proven synthetic pathway is registered. As the proofs of concept, the novel synthetic pathways for the production of isobutanol, 3-hydroxypropionate, and butyryl-CoA were predicted. The prediction shows a high reliability, in which experimentally verified synthetic pathways were listed within the top 0.089% of the identified pathway candidates. Conclusions It is expected that the system framework developed in this study would be useful for the in silico design of novel metabolic pathways to be employed for the efficient production of chemicals, fuels and materials.

Recent advances of molecular toolbox construction expand Pichia pastoris in synthetic biology applications.

Science.gov (United States)

Kang, Zhen; Huang, Hao; Zhang, Yunfeng; Du, Guocheng; Chen, Jian

2017-01-01

Pichia pastoris: (reclassified as Komagataella phaffii), a methylotrophic yeast strain has been widely used for heterologous protein production because of its unique advantages, such as readily achievable high-density fermentation, tractable genetic modifications and typical eukaryotic post-translational modifications. More recently, P. pastoris as a metabolic pathway engineering platform has also gained much attention. In this mini-review, we addressed recent advances of molecular toolboxes, including synthetic promoters, signal peptides, and genome engineering tools that established for P. pastoris. Furthermore, the applications of P. pastoris towards synthetic biology were also discussed and prospected especially in the context of genome-scale metabolic pathway analysis.

Biological hydrogen production from industrial wastewaters

Energy Technology Data Exchange (ETDEWEB)

Peixoto, Guilherme; Pantoja Filho, Jorge Luis Rodrigues; Zaiat, Marcelo [Universidade de Sao Paulo (EESC/USP), Sao Carlos, SP (Brazil). School of Engineering. Dept. Hydraulics and Sanitation], Email: peixoto@sc.usp.br

2010-07-01

This research evaluates the potential for producing hydrogen in anaerobic reactors using industrial wastewaters (glycerol from bio diesel production, wastewater from the parboilization of rice, and vinasse from ethanol production). In a complementary experiment the soluble products formed during hydrogen production were evaluated for methane generation. The assays were performed in batch reactors with 2 liters volume, and sucrose was used as a control substrate. The acidogenic inoculum was taken from a packed-bed reactor used to produce hydrogen from a sucrose-based synthetic substrate. The methanogenic inoculum was taken from an upflow anaerobic sludge blanket reactor treating poultry slaughterhouse wastewater. Hydrogen was produced from rice parboilization wastewater (24.27 ml H{sub 2} g{sup -1} COD) vinasse (22.75 ml H{sub 2} g{sup -1} COD) and sucrose (25.60 ml H{sub 2} g{sup -1} COD), while glycerol only showed potential for methane generation. (author)

The BioSCWG Project: Understanding the Trade-Offs in the Process and Thermal Design of Hydrogen and Synthetic Natural Gas Production

Directory of Open Access Journals (Sweden)

Mohamed Magdeldin

2016-10-01

Full Text Available This article presents a summary of the main findings from a collaborative research project between Aalto University in Finland and partner universities. A comparative process synthesis, modelling and thermal assessment was conducted for the production of Bio-synthetic natural gas (SNG and hydrogen from supercritical water refining of a lipid extracted algae feedstock integrated with onsite heat and power generation. The developed reactor models for product gas composition, yield and thermal demand were validated and showed conformity with reported experimental results, and the balance of plant units were designed based on established technologies or state-of-the-art pilot operations. The poly-generative cases illustrated the thermo-chemical constraints and design trade-offs presented by key process parameters such as plant organic throughput, supercritical water refining temperature, nature of desirable coproducts, downstream indirect production and heat recovery scenarios. The evaluated cases favoring hydrogen production at 5 wt. % solid content and 600 °C conversion temperature allowed higher gross syngas and CHP production. However, mainly due to the higher utility demands the net syngas production remained lower compared to the cases favoring BioSNG production. The latter case, at 450 °C reactor temperature, 18 wt. % solid content and presence of downstream indirect production recorded 66.5%, 66.2% and 57.2% energetic, fuel-equivalent and exergetic efficiencies respectively.

Development of hydrogen oxidizing bacteria using hydrogen from radiolysis or metal corrosion; Developpement de populations microbiennes oxydant l'hydrogene produit par radiolyse ou par corrosion des metaux

Energy Technology Data Exchange (ETDEWEB)

Libert, M F; Sellier, R; Marty, V; Camaro, S [CEA Cadarache, Dept. d' Entreposage et de Stockage des Dechets (DCC/DESD/SEP), 13 - Saint-Paul-lez-Durance (France)

2000-07-01

The effect of many parameters need to be studied to characterize the long term behavior of nuclear waste in a deep repository. These parameters concern the chemical effects, radiolytic effects, mechanical properties, water composition, and microbiological activity. To evaluate microbial activity in such an environment, work was focused on an inventory of key nutrients (C, H, 0, N, P, S) and energy sources required for bacterial growth. The production of hydrogen in the nuclear waste environment leads to the growth of hydrogen oxidizing bacteria, which modify the gas production balance. A deep repository containing bituminized waste drums implies several sources of hydrogen: - water radiolysis; -corrosion of metal containers; - radiolysis of the embedding matrix (bitumen). Two deep geological disposal conditions leading to H{sub 2} production in a bituminized nuclear waste environment were simulated in the present study: - H{sub 2} production by iron corrosion under anaerobic conditions was simulated by adding 10% of H{sub 2} in the atmosphere; - H{sub 2} production by radiolysis of bitumen matrix was approached by subjecting this material to external gamma irradiation with a dose rate near real conditions (6 Gy/h). The presence of dissolved H{sub 2} in water allows the growth of hydrogen oxidizing bacteria leading to: - CO{sub 2} and N{sub 2} production; - H{sub 2} consumption; - lower NO{sub 3}{sup -} concentration caused by reduction to nitrogen. In the first case, hydrogen consumption is limited by the NO{sub 3}{sup -} release rate from the bitumen matrix. In the second case, however, under gamma radiation at a low dose rate, hydrogen production is weak, and the hydrogen is completely consumed by microorganisms. Knowledge about these hydrogen oxidizing bacteria is just beginning to emerge. Heterotrophic denitrifying bacteria adapt well to hydrogen metabolism (autotrophic metabolism) by oxidizing H{sub 2} instead of hydrocarbons. (authors)

Protein design in systems metabolic engineering for industrial strain development.

Science.gov (United States)

Chen, Zhen; Zeng, An-Ping

2013-05-01

Accelerating the process of industrial bacterial host strain development, aimed at increasing productivity, generating new bio-products or utilizing alternative feedstocks, requires the integration of complementary approaches to manipulate cellular metabolism and regulatory networks. Systems metabolic engineering extends the concept of classical metabolic engineering to the systems level by incorporating the techniques used in systems biology and synthetic biology, and offers a framework for the development of the next generation of industrial strains. As one of the most useful tools of systems metabolic engineering, protein design allows us to design and optimize cellular metabolism at a molecular level. Here, we review the current strategies of protein design for engineering cellular synthetic pathways, metabolic control systems and signaling pathways, and highlight the challenges of this subfield within the context of systems metabolic engineering. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Renewable Hydrogen Carrier — Carbohydrate: Constructing the Carbon-Neutral Carbohydrate Economy

Directory of Open Access Journals (Sweden)

Y.-H. Percival Zhang

2011-01-01

Full Text Available The hydrogen economy presents an appealing energy future but its implementation must solve numerous problems ranging from low-cost sustainable production, high-density storage, costly infrastructure, to eliminating safety concern. The use of renewable carbohydrate as a high-density hydrogen carrier and energy source for hydrogen production is possible due to emerging cell-free synthetic biology technology—cell-free synthetic pathway biotransformation (SyPaB. Assembly of numerous enzymes and co-enzymes in vitro can create complicated set of biological reactions or pathways that microorganisms or catalysts cannot complete, for example, C6H10O5 (aq + 7 H2O (l à 12 H2 (g + 6 CO2 (g (PLoS One 2007, 2:e456. Thanks to 100% selectivity of enzymes, modest reaction conditions, and high-purity of generated hydrogen, carbohydrate is a promising hydrogen carrier for end users. Gravimetric density of carbohydrate is 14.8 H2 mass% if water can be recycled from proton exchange membrane fuel cells or 8.33% H2 mass% without water recycling. Renewable carbohydrate can be isolated from plant biomass or would be produced from a combination of solar electricity/hydrogen and carbon dioxide fixation mediated by high-efficiency artificial photosynthesis mediated by SyPaB. The construction of this carbon-neutral carbohydrate economy would address numerous sustainability challenges, such as electricity and hydrogen storage, CO2 fixation and long-term storage, water conservation, transportation fuel production, plus feed and food production.

Biosynthesis of therapeutic natural products using synthetic biology.

Science.gov (United States)

Awan, Ali R; Shaw, William M; Ellis, Tom

2016-10-01

Natural products are a group of bioactive structurally diverse chemicals produced by microorganisms and plants. These molecules and their derivatives have contributed to over a third of the therapeutic drugs produced in the last century. However, over the last few decades traditional drug discovery pipelines from natural products have become far less productive and far more expensive. One recent development with promise to combat this trend is the application of synthetic biology to therapeutic natural product biosynthesis. Synthetic biology is a young discipline with roots in systems biology, genetic engineering, and metabolic engineering. In this review, we discuss the use of synthetic biology to engineer improved yields of existing therapeutic natural products. We further describe the use of synthetic biology to combine and express natural product biosynthetic genes in unprecedented ways, and how this holds promise for opening up completely new avenues for drug discovery and production. Copyright © 2016 Elsevier B.V. All rights reserved.

SBOLme: a Repository of SBOL Parts for Metabolic Engineering

KAUST Repository

Kuwahara, Hiroyuki; Cui, Xuefeng; Umarov, Ramzan; Grunberg, Raik; Myers, Chris J.; Gao, Xin

2017-01-01

The Synthetic Biology Open Language (SBOL) is a community-driven open language to promote standardization in synthetic biology. To support the use of SBOL in metabolic engineering, we developed SBOLme, the first open-access repository of SBOL 2

[Advance in flavonoids biosynthetic pathway and synthetic biology].

Science.gov (United States)

Zou, Li-Qiu; Wang, Cai-Xia; Kuang, Xue-Jun; Li, Ying; Sun, Chao

2016-11-01

Flavonoids are the valuable components in medicinal plants, which possess a variety of pharmacological activities, including anti-tumor, antioxidant and anti-inflammatory activities. There is an unambiguous understanding about flavonoids biosynthetic pathway, that is,2S-flavanones including naringenin and pinocembrin are the skeleton of other flavonoids and they can transform to other flavonoids through branched metabolic pathway. Elucidation of the flavonoids biosynthetic pathway lays a solid foundation for their synthetic biology. A few flavonoids have been produced in Escherichia coli or yeast with synthetic biological technologies, such as naringenin, pinocembrin and fisetin. Synthetic biology will provide a new way to get valuable flavonoids and promote the research and development of flavonoid drugs and health products, making flavonoids play more important roles in human diet and health. Copyright© by the Chinese Pharmaceutical Association.

Hydrogen effects in duplex stainless steel welded joints - electrochemical studies

Science.gov (United States)

Michalska, J.; Łabanowski, J.; Ćwiek, J.

2012-05-01

In this work results on the influence of hydrogen on passivity and corrosion resistance of 2205 duplex stainless steel (DSS) welded joints are described. The results were discussed by taking into account three different areas on the welded joint: weld metal (WM), heat-affected zone (HAZ) and parent metal. The corrosion resistance was qualified with the polarization curves registered in a synthetic sea water. The conclusion is that, hydrogen may seriously deteriorate the passive film stability and corrosion resistance to pitting of 2205 DSS welded joints. The presence of hydrogen in passive films increases corrosion current density and decreases the potential of the film breakdown. It was also found that degree of susceptibility to hydrogen degradation was dependent on the hydrogen charging conditions. WM region has been revealed as the most sensitive to hydrogen action.

Engineering emergent multicellular behavior through synthetic adhesion

Science.gov (United States)

Glass, David; Riedel-Kruse, Ingmar

In over a decade, synthetic biology has developed increasingly robust gene networks within single cells, but constructed very few systems that demonstrate multicellular spatio-temporal dynamics. We are filling this gap in synthetic biology's toolbox by developing an E. coli self-assembly platform based on modular cell-cell adhesion. We developed a system in which adhesive selectivity is provided by a library of outer membrane-displayed peptides with intra-library specificities, while affinity is provided by consistent expression across the entire library. We further provide a biophysical model to help understand the parameter regimes in which this tool can be used to self-assemble into cellular clusters, filaments, or meshes. The combined platform will enable future development of synthetic multicellular systems for use in consortia-based metabolic engineering, in living materials, and in controlled study of minimal multicellular systems. Stanford Bio-X Bowes Fellowship.

Combination of Plant Metabolic Modules Yields Synthetic Synergies

Science.gov (United States)

Rajabi, Fatemeh; Heene, Ernst; Maisch, Jan; Nick, Peter

2017-01-01

The great potential of pharmacologically active secondary plant metabolites is often limited by low yield and availability of the producing plant. Chemical synthesis of these complex compounds is often too expensive. Plant cell fermentation offers an alternative strategy to overcome these limitations. However, production in batch cell cultures remains often inefficient. One reason might be the fact that different cell types have to interact for metabolite maturation, which is poorly mimicked in suspension cell lines. Using alkaloid metabolism of tobacco, we explore an alternative strategy, where the metabolic interactions of different cell types in a plant tissue are technically mimicked based on different plant-cell based metabolic modules. In this study, we simulate the interaction found between the nicotine secreting cells of the root and the nicotine-converting cells of the senescent leaf, generating the target compound nornicotine in the model cell line tobacco BY-2. When the nicotine demethylase NtomCYP82E4 was overexpressed in tobacco BY-2 cells, nornicotine synthesis was triggered, but only to a minor extent. However, we show here that we can improve the production of nornicotine in this cell line by feeding the precursor, nicotine. Engineering of another cell line overexpressing the key enzyme NtabMPO1 allows to stimulate accumulation and secretion of this precursor. We show that the nornicotine production of NtomCYP82E4 cells can be significantly stimulated by feeding conditioned medium from NtabMPO1 overexpressors without any negative effect on the physiology of the cells. Co-cultivation of NtomCYP82E4 with NtabMPO1 stimulated nornicotine accumulation even further, demonstrating that the physical presence of cells was superior to just feeding the conditioned medium collected from the same cells. These results provide a proof of concept that combination of different metabolic modules can improve the productivity for target compounds in plant cell

Cyanobacterial Hydrogenases and Hydrogen Metabolism Revisited: Recent Progress and Future Prospects

Directory of Open Access Journals (Sweden)

Namita Khanna

2015-05-01

Full Text Available Cyanobacteria have garnered interest as potential cell factories for hydrogen production. In conjunction with photosynthesis, these organisms can utilize inexpensive inorganic substrates and solar energy for simultaneous biosynthesis and hydrogen evolution. However, the hydrogen yield associated with these organisms remains far too low to compete with the existing chemical processes. Our limited understanding of the cellular hydrogen production pathway is a primary setback in the potential scale-up of this process. In this regard, the present review discusses the recent insight around ferredoxin/flavodoxin as the likely electron donor to the bidirectional Hox hydrogenase instead of the generally accepted NAD(PH. This may have far reaching implications in powering solar driven hydrogen production. However, it is evident that a successful hydrogen-producing candidate would likely integrate enzymatic traits from different species. Engineering the [NiFe] hydrogenases for optimal catalytic efficiency or expression of a high turnover [FeFe] hydrogenase in these photo-autotrophs may facilitate the development of strains to reach target levels of biohydrogen production in cyanobacteria. The fundamental advancements achieved in these fields are also summarized in this review.

On severe accident hydrogen behaviour in Loviisa

International Nuclear Information System (INIS)

Okkonen, T.

1996-02-01

This study is related to the hydrogen management strategy of the Loviisa ice-condenser containments. A synthetic survey is conducted of the various parts of the subject by using compact 'back-of-the-envelope' analysis methods. The analysed cases are consistent with the principal hydrogen management approaches proposed by the utility Imatran Voima Oy (IVO). The study begins by introduction of the Loviisa plant features and various severe accident types. Hydrogen generation characteristics are analysed mainly for the core degradation phase, but the hydrogen sources from molten fuel-coolant interactions and reflooding of a degraded core are discussed, as well. The hydrogen generation and release rates are compared with the overall gas convection and mixing conditions in order to estimate hydrogen concentrations in the containment. The natural convection currents are examined also from the scaling point of view, concerning the scaled-down VICTORIA tests of IVO. Finally, the potential for large deflagration loadings or local detonations is examined for the Loviisa containments. The study is concluded by preliminary subjective judgments about the most critical factors of the Loviisa hydrogen problematics and about any issues that may require additional confirmative research. (orig.) (47 refs., 4 figs., 24 tabs.)

On severe accident hydrogen behaviour in Loviisa

Energy Technology Data Exchange (ETDEWEB)

Okkonen, T. [OTO-Consulting Ay, Helsinki (Finland)

1996-02-01

This study is related to the hydrogen management strategy of the Loviisa ice-condenser containments. A synthetic survey is conducted of the various parts of the subject by using compact `back-of-the-envelope` analysis methods. The analysed cases are consistent with the principal hydrogen management approaches proposed by the utility Imatran Voima Oy (IVO). The study begins by introduction of the Loviisa plant features and various severe accident types. Hydrogen generation characteristics are analysed mainly for the core degradation phase, but the hydrogen sources from molten fuel-coolant interactions and reflooding of a degraded core are discussed, as well. The hydrogen generation and release rates are compared with the overall gas convection and mixing conditions in order to estimate hydrogen concentrations in the containment. The natural convection currents are examined also from the scaling point of view, concerning the scaled-down VICTORIA tests of IVO. Finally, the potential for large deflagration loadings or local detonations is examined for the Loviisa containments. The study is concluded by preliminary subjective judgments about the most critical factors of the Loviisa hydrogen problematics and about any issues that may require additional confirmative research. (orig.) (47 refs., 4 figs., 24 tabs.).

Study of metabolic pathways for hydrogen production in chlamydomonas reinhardtii and transposition on a torus photo bioreactor; Etude des voies metaboliques de production d'hydrogene chez la microalgue Chlamydomonas reinhardtii et transposition en photobioreacteur

Energy Technology Data Exchange (ETDEWEB)

Fouchard, S

2006-04-15

Considering the recent increase in energy consumption. aide associated environmental risks, new trails are followed today to develop the use of clean and renewable alternative energies. In this context hydrogen seems to be a serious solution and this study, based on micro-algae photosynthetic capacities exploitation, will allow to devise a process for hydrogen production from only water and solar energy without greenhouse gas release. The sulphur deprivation protocol on TAP medium, known to lead to hydrogen production in Chlamydomonas reinhardtii species was particularly studied. At the metabolic level, two important phenomena are induced under these conditions: an over-accumulation of the intracellular starch reserves and a simultaneous alteration of the PsII activity which leads to anoxia and Fe-hydrogenase induction, an enzyme with a strong specific activity responsible for the hydrogen production. The contribution of the two electron transfer pathways implied in the hydrogen production process (PsII-dependent and PSII-independent) as well as the importance of the previously accumulated starch were highlighted here. We also investigated the potential for designing autotrophic protocols for hydrogen photoproduction. Various protocols, considered to be relevant, were then transposed on a torus photo-bioreactor, specifically developed in this study and which allows the control of culture parameters as well as the precise measurement of gas release kinetics, in order to obtain first estimates of productivity of the system. Integration of the physical; aspects of the pilot and biological aspects of the process in a model, finally opens new prospects for subject development, in particular for a reasoned optimization of hydrogen production via this double physiology/process approach. (author)

Control of Redox Events by Dye Encapsulation Applied to Light-Driven Splitting of Hydrogen Sulfide

NARCIS (Netherlands)

Jing, X.; Yang, Y.; He, C.; Chang, Z.; Reek, J.N.H.; Duan, C.

2017-01-01

Solar production of hydrogen by consuming low-value waste products is an attractive pathway that has both economic and environmental benefits. Inspired by the reactive pocket of enzymes, a synthetic platform to combine photocatalytic hydrogen evolution with sulfide oxidation in a one-pot process via

Hydrogenation of carbon dioxide towards synthetic natural gas. A route to effective future energy storage

Energy Technology Data Exchange (ETDEWEB)

Schoder, M. [Hochschule Lausitz, Cottbus (Germany); Armbruster, U.; Martin, A. [Rostock Univ. (Germany). Leibniz Institute for Catalysis

2012-07-01

Ni- and Ru-based catalysts are best suited for the so-called Sabatier reaction, i.e., the hydrogenation of CO{sub 2} to synthetic natural gas (SNG). Besides using commercial materials, catalyst syntheses (5 wt% Ru or Ni) were carried out by incipient wetness impregnation of four carriers (TiO{sub 2}, SiO{sub 2}, ZrO{sub 2} and {gamma}-Al{sub 2}O{sub 3}). Some pre-tests revealed that catalysts supported on TiO{sub 2} and SiO{sub 2} mostly produced CO, and therefore, they were not studied in detail. The catalyst tests were carried out in a continuously operated tube reactor at 623-723 K and 1-20 bar. Ru/ZrO{sub 2} and Ni/{gamma}-Al{sub 2}O{sub 3} revealed best catalytic performance at ambient pressure. Methane selectivities of 99.9% at 81.2% CO{sub 2} conversion for Ru/ZrO{sub 2} (623 K) and of 98.9% at 73.8% CO{sub 2} conversion for Ni/{gamma}-Al{sub 2}O{sub 3} (673 K) were obtained. The conversion increased significantly with raising reaction pressure above 10 bar to reach more than 93% for the Ni-containing catalyst and more than 96% for the Zr catalysts. Methane as the target product was formed with a selectivity of 100%. In addition, the catalysts were characterized by various solid-state techniques such as BET, TPR, ICP-OES, XRD, XPS and TEM. (orig.)

Fuel cells: yes, please, but not fuelled with hydrogen

International Nuclear Information System (INIS)

Bossel, U.

2004-01-01

This short article takes a critical look at the fuel cell scene and criticises the fact that the word 'hydrogen' is almost always mentioned in the same breath as 'fuel cells'. Fundamental zeal that ignores physical reality and the technical possibilities available has, according to the author, led to politicians and journalists ignoring the laws of physics. The fact that hydrogen is not a source of energy but a synthetic energy carrier is stressed. The use of electricity - even if generated from renewable resources - to produce hydrogen is criticised on account of the conversion efficiencies involved. Figures are given on the overall efficiencies of a hydrogen-based energy-chain. The author recommends that novel, efficient methods of storing electricity should be promoted instead

Synthetic biology expands chemical control of microorganisms.

Science.gov (United States)

Ford, Tyler J; Silver, Pamela A

2015-10-01

The tools of synthetic biology allow researchers to change the ways engineered organisms respond to chemical stimuli. Decades of basic biology research and new efforts in computational protein and RNA design have led to the development of small molecule sensors that can be used to alter organism function. These new functions leap beyond the natural propensities of the engineered organisms. They can range from simple fluorescence or growth reporting to pathogen killing, and can involve metabolic coordination among multiple cells or organisms. Herein, we discuss how synthetic biology alters microorganisms' responses to chemical stimuli resulting in the development of microbes as toxicity sensors, disease treatments, and chemical factories. Copyright © 2015 Elsevier Ltd. All rights reserved.

Transfer Hydrogenation: Employing a Simple, In Situ Prepared Catalytic System

KAUST Repository

Ang, Eleanor Pei Ling

2017-01-01

Transfer hydrogenation has been recognized to be an important synthetic method in both academic and industrial research to obtain valuable products including alcohols. Transition metal catalysts based on precious metals, such as Ru, Rh and Ir

First characterization of AKB-48 metabolism, a novel synthetic cannabinoid, using human hepatocytes and high-resolution mass spectrometry.

Science.gov (United States)

Gandhi, Adarsh S; Zhu, Mingshe; Pang, Shaokun; Wohlfarth, Ariane; Scheidweiler, Karl B; Liu, Hua-Fen; Huestis, Marilyn A

2013-10-01

Since the federal authorities scheduled the first synthetic cannabinoids, JWH-018 and JWH-073, new synthetic cannabinoids were robustly marketed. N-(1-Adamantyl)-1-pentylindazole-3-carboxamide (AKB-48), also known as APINACA, was recently observed in Japanese herbal smoking blends. The National Forensic Laboratory Information System registered 443 reports of AKB-48 cases in the USA from March 2010 to January 2013. In May 2013, the Drug Enforcement Administration listed AKB-48 as a Schedule I drug. Recently, AKB-48 was shown to have twice the CB1 receptor binding affinity than CB2. These pharmacological effects and the difficulty in detecting the parent compound in urine highlight the importance of metabolite identification for developing analytical methods for clinical and forensic investigations. Using human hepatocytes and TripleTOF mass spectrometry, we identified 17 novel phase I and II AKB-48 metabolites, products of monohydroxylation, dihydroxylation, or trihydroxylation on the aliphatic adamantane ring or N-pentyl side chain. Glucuronide conjugation of some mono- and dihydroxylated metabolites also occurred. Oxidation and dihydroxylation on the adamantane ring and N-pentyl side chain formed a ketone. More metabolites were identified after 3 h of incubation than at 1 h. For the first time, we present a AKB-48 metabolic scheme obtained from human hepatocytes and high-resolution mass spectrometry. These data are needed to develop analytical methods to identify AKB-48 consumption in clinical and forensic testing.

Metabolism of the synthetic cannabinoids AMB-CHMICA and 5C-AKB48 in pooled human hepatocytes and rat hepatocytes analyzed by UHPLC-(IMS)-HR-MSE.

Science.gov (United States)

Mardal, Marie; Dalsgaard, Petur Weihe; Qi, Bing; Mollerup, Christian Brinch; Annaert, Pieter; Linnet, Kristian

2018-04-15

The main analytical targets of synthetic cannabinoids are often metabolites. With the high number of new psychoactive substances entering the market, suitable workflows are needed for analytical target identification in biological samples. The aims of this study were to identify the main metabolites of the synthetic cannabinoids, AMB-CHMICA and 5C-AKB48, using an in silico-assisted workflow with analytical data acquired using ultra-high-performance liquid chromatography-(ion mobility spectroscopy)-high resolution-mass spectrometry in data-independent acquisition mode (UHPLC-(IMS)-HR-MS E ). The metabolites were identified after incubation with rat and pooled human hepatocytes using UHPLC-HR-MS E , followed by UHPLC-IMS-HR-MS E . Metabolites of AMB-CHMICA and 5C-AKB48 were predicted with Meteor (Lhasa Ltd) and imported to the UNIFI software (Waters). The predicted metabolites were assigned to analytical components supported by the UNIFI in silico fragmentation tool. The main metabolic pathway of AMB-CHMICA was O-demethylation and hydroxylation of the methylhexyl moiety. For 5C-AKB48, the main metabolic pathways were hydroxylation(s) of the adamantyl moiety and oxidative dechlorination with subsequent oxidation to the ω-COOH. The matrix components in the metabolite spectra were reduced with IMS, which improved the accuracy of the spectral interpretation; however, this left fewer fragment ions for assigning sites of metabolism. Meteor was able to predict the majority of the metabolites, with the most notable exception being the oxidative dechlorination and, consequently, all metabolites that underwent that transformation pathway. Oxidative dechlorination of ω-chloroalkanes in humans has not been previously reported in the literature. The postulated metabolites can be used for screening of biological samples, with four-dimensional identification based on retention time, collision cross section, precursor ion, and fragment ions. Copyright © 2018 Elsevier B.V. All

Energy infrastructure: hydrogen energy system

Energy Technology Data Exchange (ETDEWEB)

Veziroglu, T N

1979-02-01

In a hydrogen system, hydrogen is not a primary source of energy, but an intermediary, an energy carrier between the primary energy sources and the user. The new unconventional energy sources, such as nuclear breeder reactors, fusion reactors, direct solar radiation, wind energy, ocean thermal energy, and geothermal energy have their shortcomings. These shortcomings of the new sources point out to the need for an intermediary energy system to form the link between the primary energy sources and the user. In such a system, the intermediary energy form must be transportable and storable; economical to produce; and if possible renewable and pollution-free. The above prerequisites are best met by hydrogen. Hydrogen is plentiful in the form of water. It is the cheapest synthetic fuel to manufacture per unit of energy stored in it. It is the least polluting of all of the fuels, and is the lightest and recyclable. In the proposed system, hydrogen would be produced in large plants located away from the consumption centers at the sites where primary new energy sources and water are available. Hydrogen would then be transported to energy consumption centers where it would be used in every application where fossil fuels are being used today. Once such a system is established, it will never be necessary to change to any other energy system.

Hydrogen Production via Synthetic Gas by Biomass/Oil Partial Oxidation

Czech Academy of Sciences Publication Activity Database

Hanika, Jiří; Lederer, J.; Tukač, V.; Veselý, Václav; Kováč, D.

176-177, - (2011), s. 286-290 ISSN 1385-8947. [International Conference on Chemical Reactors CHEMREACTOR-19 /19./. Vienna, 05.09.2010-09.09.2010] R&D Projects: GA MPO 2A-2TP1/024 Institutional research plan: CEZ:AV0Z40720504 Keywords : hydrogen * biomass * partial oxidation Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 3.461, year: 2011

Study of metabolic pathways for hydrogen production in chlamydomonas reinhardtii and transposition on a torus photo bioreactor; Etude des voies metaboliques de production d'hydrogene chez la microalgue Chlamydomonas reinhardtii et transposition en photobioreacteur

Energy Technology Data Exchange (ETDEWEB)

Fouchard, S

2006-04-15

Considering the recent increase in energy consumption. aide associated environmental risks, new trails are followed today to develop the use of clean and renewable alternative energies. In this context hydrogen seems to be a serious solution and this study, based on micro-algae photosynthetic capacities exploitation, will allow to devise a process for hydrogen production from only water and solar energy without greenhouse gas release. The sulphur deprivation protocol on TAP medium, known to lead to hydrogen production in Chlamydomonas reinhardtii species was particularly studied. At the metabolic level, two important phenomena are induced under these conditions: an over-accumulation of the intracellular starch reserves and a simultaneous alteration of the PsII activity which leads to anoxia and Fe-hydrogenase induction, an enzyme with a strong specific activity responsible for the hydrogen production. The contribution of the two electron transfer pathways implied in the hydrogen production process (PsII-dependent and PSII-independent) as well as the importance of the previously accumulated starch were highlighted here. We also investigated the potential for designing autotrophic protocols for hydrogen photoproduction. Various protocols, considered to be relevant, were then transposed on a torus photo-bioreactor, specifically developed in this study and which allows the control of culture parameters as well as the precise measurement of gas release kinetics, in order to obtain first estimates of productivity of the system. Integration of the physical; aspects of the pilot and biological aspects of the process in a model, finally opens new prospects for subject development, in particular for a reasoned optimization of hydrogen production via this double physiology/process approach. (author)

Development of Hydrogen Electrodes for Alkaline Water Electrolysis

DEFF Research Database (Denmark)

Kjartansdóttir, Cecilía Kristín

, production of electricity via fuel cells, fuel for internal combustion engines or gas turbines, or as a raw material for the production of synthetic fuels via Sabatier or Fischer - Tropsch process. In some situations it may be suitable to simply inject hydrogen into the existing natural gas based...... will be needed. Producing hydrogen via water electrolysis using surplus, low cost, power from renewables offers the possibility of increased production capacity and load management with no greenhouse emissions. Hydrogen is a valuable energy carrier, which is able to contribute to various forms of energy, such as...... infrastructure. Alkaline water electrolysis (AWE) is the current standard (stat of the art) for industrial large-scale water electrolysis systems. One of the main criteria for industrial AWE is efficient and durable electrodes. The aim of the present PhD study was to develop electrode materials for hydrogen...

Metabolism of the synthetic cannabinoids AMB-CHMICA and 5C-AKB48 in pooled human hepatocytes and rat hepatocytes analyzed by UHPLC-(IMS)-HR-MSE

DEFF Research Database (Denmark)

Mardal, Marie; Dalsgaard, Petur Weihe; Qi, Bing

2018-01-01

metabolites of the synthetic cannabinoids, AMB-CHMICA and 5C-AKB48, using an in silico-assisted workflow with analytical data acquired using ultra-high-performance liquid chromatography–(ion mobility spectroscopy)–high resolution–mass spectrometry in data-independent acquisition mode (UHPLC......-(IMS)-HR-MSE). The metabolites were identified after incubation with rat and pooled human hepatocytes using UHPLC-HR-MSE, followed by UHPLC-IMS-HR-MSE. Metabolites of AMB-CHMICA and 5C-AKB48 were predicted with Meteor (Lhasa Ltd) and imported to the UNIFI software (Waters). The predicted metabolites were assigned to analytical...... components supported by the UNIFI in silico fragmentation tool. The main metabolic pathway of AMB-CHMICA was O-demethylation and hydroxylation of the methylhexyl moiety. For 5C-AKB48, the main metabolic pathways were hydroxylation(s) of the adamantyl moiety and oxidative dechlorination with subsequent...

Polyamides : hydrogen bonding, the Brill transition, and superheated water

NARCIS (Netherlands)

Dijkstra - Vinken, E.

2008-01-01

Aliphatic polyamide, commonly known as nylon, was the world’s first synthetic fiber and has found its largest application range in tires, carpets, stockings, upholstery, and adhesives. All polyamides have a recurring amide group (–CONH–) present in the molecular structure with hydrogen bonds between

Major effect of hydrogen peroxide on bacterioplankton metabolism in the Northeast Atlantic.

Directory of Open Access Journals (Sweden)

Federico Baltar

Full Text Available Reactive oxygen species such as hydrogen peroxide have the potential to alter metabolic rates of marine prokaryotes, ultimately impacting the cycling and bioavailability of nutrients and carbon. We studied the influence of H2O2 on prokaryotic heterotrophic production (PHP and extracellular enzymatic activities (i.e., β-glucosidase [BGase], leucine aminopeptidase [LAPase] and alkaline phosphatase [APase] in the subtropical Atlantic. With increasing concentrations of H2O2 in the range of 100-1000 nM, LAPase, APase and BGase were reduced by up to 11, 23 and 62%, respectively, in the different water layers. Incubation experiments with subsurface waters revealed a strong inhibition of all measured enzymatic activities upon H2O2 amendments in the range of 10-500 nM after 24 h. H2O2 additions also reduced prokaryotic heterotrophic production by 36-100% compared to the rapid increases in production rates occurring in the unamended controls. Our results indicate that oxidative stress caused by H2O2 affects prokaryotic growth and hydrolysis of specific components of the organic matter pool. Thus, we suggest that oxidative stress may have important consequences on marine carbon and energy fluxes.

Hydrogen peroxide-induced pericarp browning of harvested longan fruit in association with energy metabolism.

Science.gov (United States)

Lin, Yifen; Lin, Yixiong; Lin, Hetong; Ritenour, Mark A; Shi, John; Zhang, Shen; Chen, Yihui; Wang, Hui

2017-06-15

Energy metabolism of "Fuyan" longan fruit treated with hydrogen peroxide (H 2 O 2 ), the most stable of the reactive oxygen, and its relationship to pericarp browning were investigated in this work. The results displayed that H 2 O 2 significantly decreased contents of adenosine triphosphate (ATP) and adenosine diphosphate (ADP). It also inhibited activities of H + -ATPase, Ca 2+ -ATPase and Mg 2+ -ATPase in membranes of plasma, vacuole and mitochondria during the early-storage and mid-storage (except for mitochondrial membrane Mg 2+ -ATPase). These results gave convincing evidence that the treatment of H 2 O 2 accelerating pericarp browning in harvested longans was due to a decrease of ATPase activity and available ATP content. This might break the ion homeostasis and the integrity of mitochondria, which might reduce energy charge and destroy the function and compartmentalization of cell membrane. These together aggravated browning incidence in pericarp of harvested longan fruit. Copyright © 2016 Elsevier Ltd. All rights reserved.

Hydrogen production from fusion reactors coupled with high temperature electrolysis

International Nuclear Information System (INIS)

Fillo, J.A.; Powell, J.R.; Steinberg, M.

The decreasing availability of fossil fuels emphasizes the need to develop systems which will produce synthetic fuel to substitute for and complement the natural supply. An important first step in the synthesis of liquid and gaseous fuels is the production of hydrogen. Thermonuclear fusion offers an inexhaustible source of energy for the production of hydrogen from water. Processes which may be considered for this purpose include electrolysis, thermochemical decomposition or thermochemical-electrochemical hybrid cycles. Preliminary studies at Brookhaven indicate that high temperature electrolysis has the highest potential efficiency for production of hydrogen from fusion. Depending on design electric generation efficiencies of approximately 40 to 60 percent and hydrogen production efficiencies of approximately 50 to 70 percent are projected for fusion reactors using high temperature blankets

Oxidative stress protection and glutathione metabolism in response to hydrogen peroxide and menadione in riboflavinogenic fungus Ashbya gossypii.

Science.gov (United States)

Kavitha, S; Chandra, T S

2014-11-01

Ashbya gossypii is a plant pathogen and a natural overproducer of riboflavin and is used for industrial riboflavin production. A few literature reports depict a link between riboflavin overproduction and stress in this fungus. However, the stress protection mechanisms and glutathione metabolism are not much explored in A. gossypii. In the present study, an increase in the activity of catalase and superoxide dismutase was observed in response to hydrogen peroxide and menadione. The lipid peroxide and membrane lipid peroxide levels were increased by H2O2 and menadione, indicating oxidative damage. The glutathione metabolism was altered with a significant increase in oxidized glutathione (GSSG), glutathione peroxidase (GPX), glutathione S transferase (GST), and glutathione reductase (GR) and a decrease in reduced glutathione (GSH) levels in the presence of H2O2 and menadione. Expression of the genes involved in stress mechanism was analyzed in response to the stressors by semiquantitative RT-PCR. The messenger RNA (mRNA) levels of CTT1, SOD1, GSH1, YAP1, and RIB3 were increased by H2O2 and menadione, indicating the effect of stress at the transcriptional level. A preliminary bioinformatics study for the presence of stress response elements (STRE)/Yap response elements (YRE) depicted that the glutathione metabolic genes, stress genes, and the RIB genes hosted either STRE/YRE, which may enable induction of these genes during stress.

Integrated In Silico Analysis of Pathway Designs for Synthetic Photo-Electro-Autotrophy.

Directory of Open Access Journals (Sweden)

Michael Volpers

Full Text Available The strong advances in synthetic biology enable the engineering of novel functions and complex biological features in unprecedented ways, such as implementing synthetic autotrophic metabolism into heterotrophic hosts. A key challenge for the sustainable production of fuels and chemicals entails the engineering of synthetic autotrophic organisms that can effectively and efficiently fix carbon dioxide by using sustainable energy sources. This challenge involves the integration of carbon fixation and energy uptake systems. A variety of carbon fixation pathways and several types of photosystems and other energy uptake systems can be chosen and, potentially, modularly combined to design synthetic autotrophic metabolism. Prior to implementation, these designs can be evaluated by the combination of several computational pathway analysis techniques. Here we present a systematic, integrated in silico analysis of photo-electro-autotrophic pathway designs, consisting of natural and synthetic carbon fixation pathways, a proton-pumping rhodopsin photosystem for ATP regeneration and an electron uptake pathway. We integrated Flux Balance Analysis of the heterotrophic chassis Escherichia coli with kinetic pathway analysis and thermodynamic pathway analysis (Max-min Driving Force. The photo-electro-autotrophic designs are predicted to have a limited potential for anaerobic, autotrophic growth of E. coli, given the relatively low ATP regenerating capacity of the proton pumping rhodopsin photosystems and the high ATP maintenance of E. coli. If these factors can be tackled, our analysis indicates the highest growth potential for the natural reductive tricarboxylic acid cycle and the synthetic pyruvate synthase-pyruvate carboxylate -glyoxylate bicycle. Both carbon fixation cycles are very ATP efficient, while maintaining fast kinetics, which also results in relatively low estimated protein costs for these pathways. Furthermore, the synthetic bicycles are highly

Synthetic Biology of Polyhydroxyalkanoates (PHA).

Science.gov (United States)

Meng, De-Chuan; Chen, Guo-Qiang

Microbial polyhydroxyalkanoates (PHA) are a family of biodegradable and biocompatible polyesters which have been extensively studied using synthetic biology and metabolic engineering methods for improving production and for widening its diversity. Synthetic biology has allowed PHA to become composition controllable random copolymers, homopolymers, and block copolymers. Recent developments showed that it is possible to establish a microbial platform for producing not only random copolymers with controllable monomers and their ratios but also structurally defined homopolymers and block copolymers. This was achieved by engineering the genome of Pseudomonas putida or Pseudomonas entomophiles to weaken the β-oxidation and in situ fatty acid synthesis pathways, so that a fatty acid fed to the bacteria maintains its original chain length and structures when incorporated into the PHA chains. The engineered bacterium allows functional groups in a fatty acid to be introduced into PHA, forming functional PHA, which, upon grafting, generates endless PHA variety. Recombinant Escherichia coli also succeeded in producing efficiently poly(3-hydroxypropionate) or P3HP, the strongest member of PHA. Synthesis pathways of P3HP and its copolymer P3HB3HP of 3-hydroxybutyrate and 3-hydroxypropionate were assembled respectively to allow their synthesis from glucose. CRISPRi was also successfully used to manipulate simultaneously multiple genes and control metabolic flux in E. coli to obtain a series of copolymer P3HB4HB of 3-hydroxybutyrate (3HB) and 4-hydroxybutyrate (4HB). The bacterial shapes were successfully engineered for enhanced PHA accumulation.

Nuclear Energy and Synthetic Liquid Transportation Fuels

Science.gov (United States)

McDonald, Richard

2012-10-01

This talk will propose a plan to combine nuclear reactors with the Fischer-Tropsch (F-T) process to produce synthetic carbon-neutral liquid transportation fuels from sea water. These fuels can be formed from the hydrogen and carbon dioxide in sea water and will burn to water and carbon dioxide in a cycle powered by nuclear reactors. The F-T process was developed nearly 100 years ago as a method of synthesizing liquid fuels from coal. This process presently provides commercial liquid fuels in South Africa, Malaysia, and Qatar, mainly using natural gas as a feedstock. Nuclear energy can be used to separate water into hydrogen and oxygen as well as to extract carbon dioxide from sea water using ion exchange technology. The carbon dioxide and hydrogen react to form synthesis gas, the mixture needed at the beginning of the F-T process. Following further refining, the products, typically diesel and Jet-A, can use existing infrastructure and can power conventional engines with little or no modification. We can then use these carbon-neutral liquid fuels conveniently long into the future with few adverse environmental impacts.

Precision metabolic engineering: The design of responsive, selective, and controllable metabolic systems.

Science.gov (United States)

McNerney, Monica P; Watstein, Daniel M; Styczynski, Mark P

2015-09-01

Metabolic engineering is generally focused on static optimization of cells to maximize production of a desired product, though recently dynamic metabolic engineering has explored how metabolic programs can be varied over time to improve titer. However, these are not the only types of applications where metabolic engineering could make a significant impact. Here, we discuss a new conceptual framework, termed "precision metabolic engineering," involving the design and engineering of systems that make different products in response to different signals. Rather than focusing on maximizing titer, these types of applications typically have three hallmarks: sensing signals that determine the desired metabolic target, completely directing metabolic flux in response to those signals, and producing sharp responses at specific signal thresholds. In this review, we will first discuss and provide examples of precision metabolic engineering. We will then discuss each of these hallmarks and identify which existing metabolic engineering methods can be applied to accomplish those tasks, as well as some of their shortcomings. Ultimately, precise control of metabolic systems has the potential to enable a host of new metabolic engineering and synthetic biology applications for any problem where flexibility of response to an external signal could be useful. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Synthetic biology approaches: Towards sustainable exploitation of marine bioactive molecules.

Science.gov (United States)

Seghal Kiran, G; Ramasamy, Pasiyappazham; Sekar, Sivasankari; Ramu, Meenatchi; Hassan, Saqib; Ninawe, A S; Selvin, Joseph

2018-06-01

The discovery of genes responsible for the production of bioactive metabolites via metabolic pathways combined with the advances in synthetic biology tools, has allowed the establishment of numerous microbial cell factories, for instance the yeast cell factories, for the manufacture of highly useful metabolites from renewable biomass. Genome mining and metagenomics are two platforms provide base-line data for reconstruction of genomes and metabolomes which is based in the development of synthetic/semi-synthetic genomes for marine natural products discovery. Engineered biofilms are being innovated on synthetic biology platform using genetic circuits and cell signalling systems as represillators controlling biofilm formation. Recombineering is a process of homologous recombination mediated genetic engineering, includes insertion, deletion or modification of any sequence specifically. Although this discipline considered new to the scientific domain, this field has now developed as promising endeavor on the accomplishment of sustainable exploitation of marine natural products. Copyright © 2018 Elsevier B.V. All rights reserved.

Metformin is synthetically lethal with glucose withdrawal in cancer cells.

Science.gov (United States)

Menendez, Javier A; Oliveras-Ferraros, Cristina; Cufí, Sílvia; Corominas-Faja, Bruna; Joven, Jorge; Martin-Castillo, Begoña; Vazquez-Martin, Alejandro

2012-08-01

Glucose deprivation is a distinctive feature of the tumor microecosystem caused by the imbalance between poor supply and an extraordinarily high consumption rate. The metabolic reprogramming from mitochondrial respiration to aerobic glycolysis in cancer cells (the "Warburg effect") is linked to oncogenic transformation in a manner that frequently implies the inactivation of metabolic checkpoints such as the energy rheostat AMP-activated protein kinase (AMPK). Because the concept of synthetic lethality in oncology can be applied not only to genetic and epigenetic intrinsic differences between normal and cancer cells but also to extrinsic ones such as altered microenvironment, we recently hypothesized that stress-energy mimickers such as the AMPK agonist metformin should produce metabolic synthetic lethality in a glucose-starved cell culture milieu imitating the adverse tumor growth conditions in vivo. Under standard high-glucose conditions, metformin supplementation mostly caused cell cycle arrest without signs of apoptotic cell death. Under glucose withdrawal stress, metformin supplementation circumvented the ability of oncogenes (e.g., HER2) to protect breast cancer cells from glucose-deprivation apoptosis. Significantly, representative cell models of breast cancer heterogeneity underwent massive apoptosis (by >90% in some cases) when glucose-starved cell cultures were supplemented with metformin. Our current findings may uncover crucial issues regarding the cell-autonomous metformin's anti-cancer actions: (1) The offently claimed clinically irrelevant, non-physiological concentrations needed to observe the metformin's anti-cancer effects in vitro merely underlie the artifactual interference of erroneous glucose-rich experimental conditions that poorly reflect glucose-starved in vivo conditions; (2) the preferential killing of cancer stem cells (CSC) by metformin may simply expose the best-case scenario for its synthetically lethal activity because an increased

Biotechnology and synthetic biology approaches for metabolic engineering of bioenergy crops.

Science.gov (United States)

Shih, Patrick M; Liang, Yan; Loqué, Dominique

2016-07-01

The Green Revolution has fuelled an exponential growth in human population since the mid-20th century. Due to population growth, food and energy demands will soon surpass supply capabilities. To overcome these impending problems, significant improvements in genetic engineering will be needed to complement breeding efforts in order to accelerate the improvement of agronomical traits. The new field of plant synthetic biology has emerged in recent years and is expected to support rapid, precise, and robust engineering of plants. In this review, we present recent advances made in the field of plant synthetic biology, specifically in genome editing, transgene expression regulation, and bioenergy crop engineering, with a focus on traits related to lignocellulose, oil, and soluble sugars. Ultimately, progress and innovation in these fields may facilitate the development of beneficial traits in crop plants to meet society's bioenergy needs. © 2016 The Authors. The Plant Journal published by Society for Experimental Biology and John Wiley & Sons Ltd.

Advances and prospects in metabolic engineering of Zymomonas mobilis.

Science.gov (United States)

Wang, Xia; He, Qiaoning; Yang, Yongfu; Wang, Jingwen; Haning, Katie; Hu, Yun; Wu, Bo; He, Mingxiong; Zhang, Yaoping; Bao, Jie; Contreras, Lydia M; Yang, Shihui

2018-04-05

Biorefinery of biomass-based biofuels and biochemicals by microorganisms is a competitive alternative of traditional petroleum refineries. Zymomonas mobilis is a natural ethanologen with many desirable characteristics, which makes it an ideal industrial microbial biocatalyst for commercial production of desirable bioproducts through metabolic engineering. In this review, we summarize the metabolic engineering progress achieved in Z. mobilis to expand its substrate and product ranges as well as to enhance its robustness against stressful conditions such as inhibitory compounds within the lignocellulosic hydrolysates and slurries. We also discuss a few metabolic engineering strategies that can be applied in Z. mobilis to further develop it as a robust workhorse for economic lignocellulosic bioproducts. In addition, we briefly review the progress of metabolic engineering in Z. mobilis related to the classical synthetic biology cycle of "Design-Build-Test-Learn", as well as the progress and potential to develop Z. mobilis as a model chassis for biorefinery practices in the synthetic biology era. Copyright © 2018 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Tritium labelling of PACAP-38 using a synthetic diiodinated precursor peptide

DEFF Research Database (Denmark)

Pedersen, Martin Holst Friborg; Baun, Michael

2012-01-01

In the interest of developing efficient methods for tritium labelling peptides, we here demonstrate the successful labelling of PACAP-38 (pituitary adenylate cyclase-activating polypeptide), a 38-mer peptide, using a synthetic diiodinated PACAP-38 precursor. In this example, we employ standard hy...... hydrogenation chemistry with the use of a heterogeneous palladium catalyst and carrier-free tritium gas on a tritium manifold system....

Synthetic torpor: A method for safely and practically transporting experimental animals aboard spaceflight missions to deep space

Science.gov (United States)

Griko, Yuri; Regan, Matthew D.

2018-02-01

Animal research aboard the Space Shuttle and International Space Station has provided vital information on the physiological, cellular, and molecular effects of spaceflight. The relevance of this information to human spaceflight is enhanced when it is coupled with information gleaned from human-based research. As NASA and other space agencies initiate plans for human exploration missions beyond low Earth orbit (LEO), incorporating animal research into these missions is vitally important to understanding the biological impacts of deep space. However, new technologies will be required to integrate experimental animals into spacecraft design and transport them beyond LEO in a safe and practical way. In this communication, we propose the use of metabolic control technologies to reversibly depress the metabolic rates of experimental animals while in transit aboard the spacecraft. Compared to holding experimental animals in active metabolic states, the advantages of artificially inducing regulated, depressed metabolic states (called synthetic torpor) include significantly reduced mass, volume, and power requirements within the spacecraft owing to reduced life support requirements, and mitigated radiation- and microgravity-induced negative health effects on the animals owing to intrinsic physiological properties of torpor. In addition to directly benefitting animal research, synthetic torpor-inducing systems will also serve as test beds for systems that may eventually hold human crewmembers in similar metabolic states on long-duration missions. The technologies for inducing synthetic torpor, which we discuss, are at relatively early stages of development, but there is ample evidence to show that this is a viable idea and one with very real benefits to spaceflight programs. The increasingly ambitious goals of world's many spaceflight programs will be most quickly and safely achieved with the help of animal research systems transported beyond LEO; synthetic torpor may

Perturbation of formate pathway for hydrogen production by expressions of formate hydrogen lyase and its transcriptional activator in wild Enterobacter aerogenes and its mutants

Energy Technology Data Exchange (ETDEWEB)

Lu, Yuan; Zhao, Hongxin; Zhang, Chong; Lai, Qiheng; Xing, Xin-Hui [Institute of Biochemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084 (China)

2009-06-15

To examine perturbation effects of formate pathway on hydrogen productivity in Enterobacter aerogenes (Ea), formate dehydrogenase FDH-H gene (fdhF) and formate hydrogen lyase activator protein FHLA gene (fhlA) originated from Escherichia coli, were overexpressed in the wild strain Ea, its hycA-deleted mutant (A) by knockout the formate hydrogen lyase repressor and hybO-deleted mutant (O) by knockout of the uptake hydrogenase, respectively. Overexpression of fdhF and fhlA promoted cell growth and volumetric hydrogen production rates of all the strains, and the hydrogen production per gram cell dry weight (CDW) for Ea, A and O was increased by 38.5%, 21.8% and 5.25%, respectively. The fdhF and fhlA overexpression improved the hydrogen yield per mol glucose of strains Ea and A, but declined that of strain O. The increase of hydrogen yield of the strain Ea with fdhF and fhlA expression was mainly attributed to the increase of formate pathway, while for the mutant A, the improved hydrogen yield with fdhF and fhlA expression was mainly due to the increase of NADH pathway. Analysis of the metabolites and ratio of ethanol-to-acetate showed that the cellular redox state balance and energy level were also changed for these strains by fdhF and fhlA expression. These findings demonstrated that the hydrogen production was not only dependent on the hydrogenase genes, but was also affected by the regulation of the whole metabolism. Therefore, fdhF and fhlA expression in different strains of E. aerogenes could exhibit different perturbation effects on the metabolism and the hydrogen productivity. (author)

Enhanced dark hydrogen fermentation by addition of ferric oxide nanoparticles using Enterobacter aerogenes.

Science.gov (United States)

Lin, Richen; Cheng, Jun; Ding, Lingkan; Song, Wenlu; Liu, Min; Zhou, Junhu; Cen, Kefa

2016-05-01

Ferric oxide nanoparticles (FONPs) were used to facilitate dark hydrogen fermentation using Enterobacter aerogenes. The hydrogen yield of glucose increased from 164.5±2.29 to 192.4±1.14mL/g when FONPs concentration increased from 0 to 200mg/L. SEM images of E. aerogenes demonstrated the existence of bacterial nanowire among cells, suggesting FONPs served as electron conduits to enhance electron transfer. TEM showed cellular internalization of FONPs, indicating hydrogenase synthesis and activity was potentially promoted due to the released iron element. When further increasing FONPs concentration to 400mg/L, the hydrogen yield of glucose decreased to 147.2±2.54mL/g. Soluble metabolic products revealed FONPs enhanced acetate pathway of hydrogen production, but weakened ethanol pathway. This shift of metabolic pathways allowed more nicotinamide adenine dinucleotide for reducing proton to hydrogen. Copyright © 2016 Elsevier Ltd. All rights reserved.

Microaeration for hydrogen sulfide removal in UASB reactor.

Science.gov (United States)

Krayzelova, Lucie; Bartacek, Jan; Kolesarova, Nina; Jenicek, Pavel

2014-11-01

The removal of hydrogen sulfide from biogas by microaeration was studied in Up-flow Anaerobic Sludge Blanket (UASB) reactors treating synthetic brewery wastewater. A fully anaerobic UASB reactor served as a control while air was dosed into a microaerobic UASB reactor (UMSB). After a year of operation, sulfur balance was described in both reactors. In UASB, sulfur was mainly presented in the effluent as sulfide (49%) and in biogas as hydrogen sulfide (34%). In UMSB, 74% of sulfur was detected in the effluent (41% being sulfide and 33% being elemental sulfur), 10% accumulated in headspace as elemental sulfur and 9% escaped in biogas as hydrogen sulfide. The efficiency of hydrogen sulfide removal in UMSB was on average 73%. Microaeration did not cause any decrease in COD removal or methanogenic activity in UMSB and the elemental sulfur produced by microaeration did not accumulate in granular sludge. Copyright © 2014 Elsevier Ltd. All rights reserved.

Synthetic biology, inspired by synthetic chemistry.

Science.gov (United States)

Malinova, V; Nallani, M; Meier, W P; Sinner, E K

2012-07-16

The topic synthetic biology appears still as an 'empty basket to be filled'. However, there is already plenty of claims and visions, as well as convincing research strategies about the theme of synthetic biology. First of all, synthetic biology seems to be about the engineering of biology - about bottom-up and top-down approaches, compromising complexity versus stability of artificial architectures, relevant in biology. Synthetic biology accounts for heterogeneous approaches towards minimal and even artificial life, the engineering of biochemical pathways on the organismic level, the modelling of molecular processes and finally, the combination of synthetic with nature-derived materials and architectural concepts, such as a cellular membrane. Still, synthetic biology is a discipline, which embraces interdisciplinary attempts in order to have a profound, scientific base to enable the re-design of nature and to compose architectures and processes with man-made matter. We like to give an overview about the developments in the field of synthetic biology, regarding polymer-based analogs of cellular membranes and what questions can be answered by applying synthetic polymer science towards the smallest unit in life, namely a cell. Copyright © 2012 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

A novel approach of modeling continuous dark hydrogen fermentation.

Science.gov (United States)

Alexandropoulou, Maria; Antonopoulou, Georgia; Lyberatos, Gerasimos

2018-02-01

In this study a novel modeling approach for describing fermentative hydrogen production in a continuous stirred tank reactor (CSTR) was developed, using the Aquasim modeling platform. This model accounts for the key metabolic reactions taking place in a fermentative hydrogen producing reactor, using fixed stoichiometry but different reaction rates. Biomass yields are determined based on bioenergetics. The model is capable of describing very well the variation in the distribution of metabolic products for a wide range of hydraulic retention times (HRT). The modeling approach is demonstrated using the experimental data obtained from a CSTR, fed with food industry waste (FIW), operating at different HRTs. The kinetic parameters were estimated through fitting to the experimental results. Hydrogen and total biogas production rates were predicted very well by the model, validating the basic assumptions regarding the implicated stoichiometric biochemical reactions and their kinetic rates. Copyright © 2017 Elsevier Ltd. All rights reserved.

The PLOS ONE Synthetic Biology Collection: Six Years and Counting

Science.gov (United States)

Peccoud, Jean; Isalan, Mark

2012-01-01

Since it was launched in 2006, PLOS ONE has published over fifty articles illustrating the many facets of the emerging field of synthetic biology. This article reviews these publications by organizing them into broad categories focused on DNA synthesis and assembly techniques, the development of libraries of biological parts, the use of synthetic biology in protein engineering applications, and the engineering of gene regulatory networks and metabolic pathways. Finally, we review articles that describe enabling technologies such as software and modeling, along with new instrumentation. In order to increase the visibility of this body of work, the papers have been assembled into the PLOS ONE Synthetic Biology Collection (www.ploscollections.org/synbio). Many of the innovative features of the PLOS ONE web site will help make this collection a resource that will support a lively dialogue between readers and authors of PLOS ONE synthetic biology papers. The content of the collection will be updated periodically by including relevant articles as they are published by the journal. Thus, we hope that this collection will continue to meet the publishing needs of the synthetic biology community. PMID:22916228

Thermochemical hydrogen production based on magnetic fusion

International Nuclear Information System (INIS)

Krikorian, O.H.; Brown, L.C.

1982-01-01

Conceptual design studies have been carried out on an integrated fusion/chemical plant system using a Tandem Mirror Reactor fusion energy source to drive the General Atomic Sulfur-Iodine Water-Splitting Cycle and produce hydrogen as a future feedstock for synthetic fuels. Blanket design studies for the Tandem Mirror Reactor show that several design alternatives are available for providing heat at sufficiently high temperatures to drive the General Atomic Cycle. The concept of a Joule-boosted decomposer is introduced in one of the systems investigated to provide heat electrically for the highest temperature step in the cycle (the SO 3 decomposition step), and thus lower blanket design requirements and costs. Flowsheeting and conceptual process designs have been developed for a complete fusion-driven hydrogen plant, and the information has been used to develop a plot plan for the plant and to estimate hydrogen production costs. Both public and private utility financing approaches have been used to obtain hydrogen production costs of $12-14/GJ based on July 1980 dollars

Synthetic routes to some isotopically labelled intermediates for diterpenoid biosynthesis

International Nuclear Information System (INIS)

Dawson, R.M.; Godfrey, I.M.; Hogg, R.W.; Knox, J.R.

1989-01-01

The exo-15-hydrogen of ent-kaurene can be exchanged through a reversible ene reaction in a convenient and efficient procedure which has the potential for giving high specific activity 3 H-labelling. Copalol, the (Z)-double bond stereoisomer, and the allylic alcohol isomers ent-manool and ent-epimanool have been obtained through divergent synthetic pathways involving a 15,16-bisnor ketone intermediate. These pathways have also allowed the four compounds to be obtained with 14 C-labelling. A method, involving a Wittig reaction to form a vinyl bromide intermediate, has been developed for obtaining copalol, as the trityl ether derivative, with stereospecific isotopic labelling of one or the other of the hydrogens of the exocyclic methylene group. 27 refs., figs

Corynebacterium glutamicum for Sustainable Bioproduction: From Metabolic Physiology to Systems Metabolic Engineering.

Science.gov (United States)

Becker, Judith; Gießelmann, Gideon; Hoffmann, Sarah Lisa; Wittmann, Christoph

Since its discovery 60 years ago, Corynebacterium glutamicum has evolved into a workhorse for industrial biotechnology. Traditionally well known for its remarkable capacity to produce amino acids, this Gram-positive soil bacterium, has become a flexible, efficient production platform for various bulk and fine chemicals, materials, and biofuels. The central turnstile of all these achievements is our excellent understanding of its metabolism and physiology. This knowledge base, together with innovative systems metabolic engineering concepts, which integrate systems and synthetic biology into strain engineering, has upgraded C. glutamicum into one of the most successful industrial microorganisms in the world.

De Novo Metabolic Engineering and the Promise of Synthetic DNA

Science.gov (United States)

Klein-Marcuschamer, Daniel; Yadav, Vikramaditya G.; Ghaderi, Adel; Stephanopoulos, Gregory N.

The uncertain price and tight supply of crude oil and the ever-increasing demand for clean energy have prompted heightened attention to the development of sustainable fuel technologies that ensure continued economic development while maintaining stewardship of the environment. In the face of these enormous challenges, biomass has emerged as a viable alternative to petroleum for the production of energy, chemicals, and materials owing to its abundance, inexpensiveness, and carbon-neutrality. Moreover, the immense ease and efficiency of biological systems at converting biomass-derived feedstocks into fuels, chemicals, and materials has generated renewed interest in biotechnology as a replacement for traditional chemical processes. Aided by the ever-expanding repertoire of microbial genetics and plant biotechnology, improved understanding of gene regulation and cellular metabolism, and incessantly accumulating gene and protein data, scientists are now contemplating engineering microbial cell factories to produce fuels, chemical feedstocks, polymers and pharmaceuticals in an economically and environmentally sustainable way. This goal resonates with that of metabolic engineering - the improvement of cellular properties through the intelligent design, rational modification, or directed evolution of biochemical pathways, and arguably, metabolic engineering seems best positioned to achieve the concomittant goals of environmental stewardship and economic prolificity.

Metabolite damage and repair in metabolic engineering design.

Science.gov (United States)

Sun, Jiayi; Jeffryes, James G; Henry, Christopher S; Bruner, Steven D; Hanson, Andrew D

2017-11-01

The necessarily sharp focus of metabolic engineering and metabolic synthetic biology on pathways and their fluxes has tended to divert attention from the damaging enzymatic and chemical side-reactions that pathway metabolites can undergo. Although historically overlooked and underappreciated, such metabolite damage reactions are now known to occur throughout metabolism and to generate (formerly enigmatic) peaks detected in metabolomics datasets. It is also now known that metabolite damage is often countered by dedicated repair enzymes that undo or prevent it. Metabolite damage and repair are highly relevant to engineered pathway design: metabolite damage reactions can reduce flux rates and product yields, and repair enzymes can provide robust, host-independent solutions. Herein, after introducing the core principles of metabolite damage and repair, we use case histories to document how damage and repair processes affect efficient operation of engineered pathways - particularly those that are heterologous, non-natural, or cell-free. We then review how metabolite damage reactions can be predicted, how repair reactions can be prospected, and how metabolite damage and repair can be built into genome-scale metabolic models. Lastly, we propose a versatile 'plug and play' set of well-characterized metabolite repair enzymes to solve metabolite damage problems known or likely to occur in metabolic engineering and synthetic biology projects. Copyright © 2017 International Metabolic Engineering Society. All rights reserved.

Metabolite damage and repair in metabolic engineering design

Energy Technology Data Exchange (ETDEWEB)

Sun, Jiayi; Jeffryes, James G.; Henry, Christopher S.; Bruner, Steven D.; Hanson, Andrew D.

2017-11-01

The necessarily sharp focus of metabolic engineering and metabolic synthetic biology on pathways and their fluxes has tended to divert attention from the damaging enzymatic and chemical side-reactions that pathway metabolites can undergo. Although historically overlooked and underappreciated, such metabolite damage reactions are now known to occur throughout metabolism and to generate (formerly enigmatic) peaks detected in metabolomics datasets. It is also now known that metabolite damage is often countered by dedicated repair enzymes that undo or prevent it. Metabolite damage and repair are highly relevant to engineered pathway design: metabolite damage reactions can reduce flux rates and product yields, and repair enzymes can provide robust, host-independent solutions. Herein, after introducing the core principles of metabolite damage and repair, we use case histories to document how damage and repair processes affect efficient operation of engineered pathways - particularly those that are heterologous, non-natural, or cell-free. We then review how metabolite damage reactions can be predicted, how repair reactions can be prospected, and how metabolite damage and repair can be built into genome-scale metabolic models. Lastly, we propose a versatile 'plug and play' set of well-characterized metabolite repair enzymes to solve metabolite damage problems known or likely to occur in metabolic engineering and synthetic biology projects.

Potential Fusion Market for Hydrogen Production Under Environmental Constraints

International Nuclear Information System (INIS)

Konishi, Satoshi

2005-01-01

Potential future hydrogen market and possible applications of fusion were analyzed. Hydrogen is expected as a major energy and fuel mediun for the future, and various processes for hydrogen production can be considered as candidates for the use of fusion energy. In order to significantly contribute to reduction of CO 2 emission, fusion must be deployed in developing countries, and must substitute fossil based energy with synthetic fuel such as hydrogen. Hydrogen production processes will have to evaluated and compared from the aspects of energy efficiency and CO 2 emission. Fusion can provide high temperature heat that is suitable for vapor electrolysis, thermo-chemical water decomposition and steam reforming with biomass waste. That is a possible advantage of fusion over renewables and Light water power reactor. Despite of its technical difficulty, fusion is also expected to have less limitation for siting location in the developing countries. Under environmental constraints, fusion has a chance to be a major primary energy source, and production of hydrogen enhances its contribution, while in 'business as usual', fusion will not be selected in the market. Thus if fusion is to be largely used in the future, meeting socio-economic requirements would be important

[Hydrogen production and enzyme activity of acidophilic strain X-29 at different C/N ratio].

Science.gov (United States)

Li, Qiu-bo; Xing, De-feng; Ren, Nan-qi; Zhao, Li-hua; Song, Ye-ying

2006-04-01

Some fermentative bacteria can produce hydrogen by utilizing carbohydrate and other kinds of organic compounds as substrates. Hydrogen production was also determined by both the limiting of growth and related enzyme activity in energy metabolism. Carbon and nitrogen are needed for the growth and metabolism of microorganisms. In addition, the carbon/nitrogen (C/N) ratio can influence the material metabolized and the energy produced. In order to improve the hydrogen production efficiency of the bacteria, we analyzed the effect of different C/N ratios on hydrogen production and the related enzyme activities in the acidophilic strain X-29 using batch test. The results indicate that the differences in the metabolism level and enzyme activity are obvious at different C/N ratios. Although the difference in liquid fermentative products produced per unit of biomass is not obvious, hydrogen production is enhanced at a specifically determined ratio. At a C/N ratio of 14 the accumulative hydrogen yield of strain X-29 reaches the maximum, 2210.9 mL/g. At different C/N ratios, the expression of hydrogenase activity vary; the activity of hydrogenase decrease quickly after reaching a maximum along with the fermentation process, but the time of expression is short. The activity of alcohol dehydrogenase (ADH) tend to stabilize after reaching a peak along with the fermentation process, the difference in expression activity is little, and the expression period is long at different C/N ratios. At a C/N ratio of 14 hydrogenase and ADH reach the maximum 2.88 micromol x (min x mg)(-1) and 33.2 micromol x (min x mg)(-1), respectively. It is shown that the C/N ratio has an important effect on enhancing hydrogen production and enzyme activity.

Molecular Cloning Designer Simulator (MCDS: All-in-one molecular cloning and genetic engineering design, simulation and management software for complex synthetic biology and metabolic engineering projects

Directory of Open Access Journals (Sweden)

Zhenyu Shi

2016-12-01

Full Text Available Molecular Cloning Designer Simulator (MCDS is a powerful new all-in-one cloning and genetic engineering design, simulation and management software platform developed for complex synthetic biology and metabolic engineering projects. In addition to standard functions, it has a number of features that are either unique, or are not found in combination in any one software package: (1 it has a novel interactive flow-chart user interface for complex multi-step processes, allowing an integrated overview of the whole project; (2 it can perform a user-defined workflow of cloning steps in a single execution of the software; (3 it can handle multiple types of genetic recombineering, a technique that is rapidly replacing classical cloning for many applications; (4 it includes experimental information to conveniently guide wet lab work; and (5 it can store results and comments to allow the tracking and management of the whole project in one platform. MCDS is freely available from https://mcds.codeplex.com. Keywords: BioCAD, Genetic engineering software, Molecular cloning software, Synthetic biology, Workflow simulation and management

Cellular metabolism

International Nuclear Information System (INIS)

Hildebrand, C.E.; Walters, R.A.

1977-01-01

Progress is reported on the following research projects: chromatin structure; the use of circular synthetic polydeoxynucleotides as substrates for the study of DNA repair enzymes; human cellular kinetic response following exposure to DNA-interactive compounds; histone phosphorylation and chromatin structure in cell proliferation; photoaddition products induced in chromatin by uv light; pollutants and genetic information transfer; altered RNA metabolism as a function of cadmium accumulation and intracellular distribution in cultured cells; and thymidylate chromophore destruction by water free radicals

Meeting report - Which role for hydrogen in the energy system?

International Nuclear Information System (INIS)

Dupre La Tour, Stephane; Raimondo, E.

2015-01-01

Before giving some general information about the activities of the SFEN, about some events regarding the energy sector, and about meetings to come, a contribution is proposed on the role of hydrogen in the energy system. The author recalls the industrial methods used to produce hydrogen (water electrolysis, reforming of fossil fuels), indicates the main applications (fuel cells, power-to-gas, industrial applications, fuel for transport). He discusses the potential of hydrogen as a good energy vector for the future. Required technical advances are identified, as well as potential industrial applications. The competitiveness of the different hydrogen production technologies is discussed, and the different uses are more precisely described and discussed (principle of fuel cell, French researches on hybrid vehicle, application to heavy vehicles, perspectives for air transport). Other technological issues are briefly addressed: direct injection of hydrogen in gas distribution network or production of synthetic methane, combined hydrolysis of CO 2 and H 2 O, hydrogen storage. After having outlined some remaining questions about the exploitation of hydrogen as energy vector, the author proposes some guidelines for the future: development of tools to analyse the competitiveness of hydrogen uses, improvement of existing technologies in terms of performance and costs, development of breakthrough technologies

Process for the exchange of hydrogen isotopes using a catalyst packed bed assembly

International Nuclear Information System (INIS)

Butler, J.P.; den Hartog, J.; Molson, F.W.R.

1978-01-01

A process for the exchange of hydrogen isotopes between streams of gaseous hydrogen and liquid water is described, wherein the streams of liquid water and gaseous hydrogen are simultaneously brought into contact with one another and a catalyst packed bed assembly while at a temperature in the range 273 0 to 573 0 K. The catalyst packed bed assembly may be composed of discrete carrier bodies of e.g. ceramics, metals, fibrous materials or synthetic plastics with catalytically active metal crystallites selected from Group VIII of the Periodic Table, partially enclosed in and bonded to the carrier bodies by a water repellent, water vapor and hydrogen gas permeable, porous, polymeric material, and discrete packing bodies having an exterior surface which is substantially hydrophilic and relatively noncatalytically active with regard to hydrogen isotope exchange between hydrogen gas and water vapor to that of the catalyst bodies

Radioassay for hydrogenase activity in viable cells and documentation of aerobic hydrogen-consuming bacteria living in extreme environments

International Nuclear Information System (INIS)

Schink, B.; Lupton, F.S.; Zeikus, J.G.

1983-01-01

An isotopic tracer assay based on the hydrogenase-dependent formation of tritiated water from tritium gas was developed for in life analysis of microbial hydrogen transformation. This method allowed detection of bacterial hydrogen metabolism in pure cultures or in natural samples obtained from aquatic ecosystems. A differentiation between chemical-biological and aerobic-anaerobic hydrogen metabolism was established by variation of the experimental incubation temperature or by addition of selective inhibitors. Hydrogenase activity was shown to be proportional to the consumption or production of hydrogen by cultures of Desulfovibrio vulgaris, Clostridium pasteurianum, and Methanosarcina barkeri. This method was applied, in connection with measurements of free hydrogen and most-probable-number enumerations, in aerobic natural source waters to establish the activity and document the ecology of hydrogen-consuming bacteria in extreme acid, thermal, or saline environments. The utility of the assay is based in part on the ability to quantify bacterial hydrogen transformation at natural hydrogen partial pressures, without the use of artificial electron acceptors

Wind energy-hydrogen storage hybrid power generation

Energy Technology Data Exchange (ETDEWEB)

Wenjei Yang; Orhan Aydin [University of Michigan, Ann Arbor, MI (United States). Dept. of Mechanical Engineering and Applied Mechanics

2001-07-01

In this theoretical investigation, a hybrid power generation system utilizing wind energy and hydrogen storage is presented. Firstly, the available wind energy is determined, which is followed by evaluating the efficiency of the wind energy conversion system. A revised model of windmill is proposed from which wind power density and electric power output are determined. When the load demand is less than the output of the generation, the excess electric power is relayed to the electrolytic cell where it is used to electrolyse the de-ionized water. Hydrogen thus produced can be stored as hydrogen compressed gas or liquid. Once the hydrogen is stored in an appropriate high-pressure vessel, it can be used in a combustion engine, fuel cell, or burned in a water-cooled burner to produce a very high-quality steam for space heating, or to drive a turbine to generate electric power. It can also be combined with organic materials to produce synthetic fuels. The conclusion is that the system produces no harmful waste and depletes no resources. Note that this system also works well with a solar collector instead of a windmill. (author)

3rd congress on applied synthetic biology in Europe (Costa da Caparica, Portugal, February 2016).

Science.gov (United States)

Cueva, Miguel

2017-03-25

The third meeting organised by the European Federation of Biotechnology (EFB) on advances in Applied Synthetic Biotechnology in Europe (ASBE) was held in Costa da Caparica, Portugal, in February 2016. Abundant novel applications in synthetic biology were described in the six sessions of the meeting, which was divided into technology and tools for synthetic biology (I, II and III), bionanoscience, biosynthetic pathways and enzyme synthetic biology, and metabolic engineering and chemical manufacturing. The meeting presented numerous methods for the development of novel synthetic strains, synthetic biological tools and synthetic biology applications. With the aid of synthetic biology, production costs of chemicals, metabolites and food products are expected to decrease, by generating sustainable biochemical production of such resources. Also, such synthetic biological advances could be applied for medical purposes, as in pharmaceuticals and for biosensors. Recurrent, linked themes throughout the meeting were the shortage of resources, the world's transition into a bioeconomy, and how synthetic biology is helping tackle these issues through cutting-edge technologies. While there are still limitations in synthetic biology research, innovation is propelling the development of technology, the standardisation of synthetic biological tools and the use of suitable host organisms. These developments are laying a foundation to providing a future where cutting-edge research could generate potential solutions to society's pressing issues, thus incentivising a transition into a bioeconomy. Copyright © 2016 Elsevier B.V. All rights reserved.

Rubisco mutants of Chlamydomonas reinhardtii enhance photosynthetic hydrogen production.

Science.gov (United States)

Pinto, T S; Malcata, F X; Arrabaça, J D; Silva, J M; Spreitzer, R J; Esquível, M G

2013-06-01

Molecular hydrogen (H2) is an ideal fuel characterized by high enthalpy change and lack of greenhouse effects. This biofuel can be released by microalgae via reduction of protons to molecular hydrogen catalyzed by hydrogenases. The main competitor for the reducing power required by the hydrogenases is the Calvin cycle, and rubisco plays a key role therein. Engineered Chlamydomonas with reduced rubisco levels, activity and stability was used as the basis of this research effort aimed at increasing hydrogen production. Biochemical monitoring in such metabolically engineered mutant cells proceeded in Tris/acetate/phosphate culture medium with S-depletion or repletion, both under hypoxia. Photosynthetic activity, maximum photochemical efficiency, chlorophyll and protein levels were all measured. In addition, expression of rubisco, hydrogenase, D1 and Lhcb were investigated, and H2 was quantified. At the beginning of the experiments, rubisco increased followed by intense degradation. Lhcb proteins exhibited monomeric isoforms during the first 24 to 48 h, and D1 displayed sensitivity under S-depletion. Rubisco mutants exhibited a significant decrease in O2 evolution compared with the control. Although the S-depleted medium was much more suitable than its complete counterpart for H2 production, hydrogen release was observed also in sealed S-repleted cultures of rubisco mutated cells under low-moderate light conditions. In particular, the rubisco mutant Y67A accounted for 10-15-fold higher hydrogen production than the wild type under the same conditions and also displayed divergent metabolic parameters. These results indicate that rubisco is a promising target for improving hydrogen production rates in engineered microalgae.

Application of synthetic biology for production of chemicals in yeast Saccharomyces cerevisiae

DEFF Research Database (Denmark)

Borodina, Irina; Li, Mingji

2015-01-01

Synthetic biology and metabolic engineering enable generation of novel cell factories that efficiently convert renewable feedstocks into biofuels, bulk, and fine chemicals, thus creating the basis for biosustainable economy independent on fossil resources. While over a hundred proof...... biology has the potential to bring down this cost by improving our ability to predictably engineer biological systems. This review highlights synthetic biology applications for design, assembly, and optimization of non-native biochemical pathways in baker's yeast Saccharomyces cerevisiae. We describe......-of-concept chemicals have been made in yeast, only a very small fraction of those has reached commercial-scale production so far. The limiting factor is the high research cost associated with the development of a robust cell factory that can produce the desired chemical at high titer, rate, and yield. Synthetic...

Production of biofuels and biochemicals by in vitro synthetic biosystems: Opportunities and challenges.

Science.gov (United States)

Zhang, Yi-Heng Percival

2015-11-15

The largest obstacle to the cost-competitive production of low-value and high-impact biofuels and biochemicals (called biocommodities) is high production costs catalyzed by microbes due to their inherent weaknesses, such as low product yield, slow reaction rate, high separation cost, intolerance to toxic products, and so on. This predominant whole-cell platform suffers from a mismatch between the primary goal of living microbes - cell proliferation and the desired biomanufacturing goal - desired products (not cell mass most times). In vitro synthetic biosystems consist of numerous enzymes as building bricks, enzyme complexes as building modules, and/or (biomimetic) coenzymes, which are assembled into synthetic enzymatic pathways for implementing complicated bioreactions. They emerge as an alternative solution for accomplishing a desired biotransformation without concerns of cell proliferation, complicated cellular regulation, and side-product formation. In addition to the most important advantage - high product yield, in vitro synthetic biosystems feature several other biomanufacturing advantages, such as fast reaction rate, easy product separation, open process control, broad reaction condition, tolerance to toxic substrates or products, and so on. In this perspective review, the general design rules of in vitro synthetic pathways are presented with eight supporting examples: hydrogen, n-butanol, isobutanol, electricity, starch, lactate,1,3-propanediol, and poly-3-hydroxylbutyrate. Also, a detailed economic analysis for enzymatic hydrogen production from carbohydrates is presented to illustrate some advantages of this system and the remaining challenges. Great market potentials will motivate worldwide efforts from multiple disciplines (i.e., chemistry, biology and engineering) to address the remaining obstacles pertaining to cost and stability of enzymes and coenzymes, standardized building parts and modules, biomimetic coenzymes, biosystem optimization, and scale

Energetic hydrogen in Brazil: subsidies for competitiveness police, 2010-2025. Critical and sensitive technologies in priority sectors; Hidrogenio energetico no Brasil: subsidios para politicas de competitividade, 2010-2025. Tecnologias criticas e sensiveis em setores prioritarios

Energy Technology Data Exchange (ETDEWEB)

NONE

2010-08-15

The report presents an introduction to the hydrogen technology, with proposals of incentives for hydrogen economy, hydrogen production, hydrogen logistic development and hydrogen use systems with relation to the internacional and national environment, considerations, bottlenecks and proposals and a synthetic chart of recommendations.

Engineering bacterial motility towards hydrogen-peroxide.

Science.gov (United States)

Virgile, Chelsea; Hauk, Pricila; Wu, Hsuan-Chen; Shang, Wu; Tsao, Chen-Yu; Payne, Gregory F; Bentley, William E

2018-01-01

Synthetic biologists construct innovative genetic/biological systems to treat environmental, energy, and health problems. Many systems employ rewired cells for non-native product synthesis, while a few have employed the rewired cells as 'smart' devices with programmable function. Building on the latter, we developed a genetic construct to control and direct bacterial motility towards hydrogen peroxide, one of the body's immune response signaling molecules. A motivation for this work is the creation of cells that can target and autonomously treat disease, the latter signaled by hydrogen peroxide release. Bacteria naturally move towards a variety of molecular cues (e.g., nutrients) in the process of chemotaxis. In this work, we engineered bacteria to recognize and move towards hydrogen peroxide, a non-native chemoattractant and potential toxin. Our system exploits oxyRS, the native oxidative stress regulon of E. coli. We first demonstrated H2O2-mediated upregulation motility regulator, CheZ. Using transwell assays, we showed a two-fold increase in net motility towards H2O2. Then, using a 2D cell tracking system, we quantified bacterial motility descriptors including velocity, % running (of tumble/run motions), and a dynamic net directionality towards the molecular cue. In CheZ mutants, we found that increased H2O2 concentration (0-200 μM) and induction time resulted in increased running speeds, ultimately reaching the native E. coli wild-type speed of ~22 μm/s with a ~45-65% ratio of running to tumbling. Finally, using a microfluidic device with stable H2O2 gradients, we characterized responses and the potential for "programmed" directionality towards H2O2 in quiescent fluids. Overall, the synthetic biology framework and tracking analysis in this work will provide a framework for investigating controlled motility of E. coli and other 'smart' probiotics for signal-directed treatment.

Future developments and technological and economic assessment of methods for producing synthetic liquid fuel from coal

Energy Technology Data Exchange (ETDEWEB)

Shlikhter, E B; Khor' kov, A V; Zhorov, Yu M

1980-11-01

Promising methods for obtaining synthetic liquid fuel from coal are surveyed and described: thermal dissolution of coal by means of a hydrogen donor solution: hydrogenation; gasification with subsequent synthesis and pyrolysis. A technological and economic assessment of the above processes is given. Emphasis is placed on methods employing catalytic conversion of methanol into hydrocarbon fuels. On the basis of thermodynamic calculations of the process for obtaining high-calorific liquid fuel from methanol the possibility of obtaining diesel fractions as well as gasoline is demonstrated. (12 refs.) (In Russian)

Hydrogen: Its Future Role in the Nation's Energy Economy.

Science.gov (United States)

Winsche, W E; Hoffman, K C; Salzano, F J

1973-06-29

electrolysis, from coal, and directly from thermal energy could be found that are less expensive than those now available; inexpensive fuel cells could be developed, and high-temperature turbines could be used for the efficient conversion of hydrogen (and oxygen) to electricity. The use of hydrogen as an automotive fuel would be a key factor in the development of a hydrogen energy economy, and safe storage techniques for carrying sufficient quantities of hydrogen in automotive systems can certainly be developed. The use of hydrogen in automobiles would significantly reduce urban pollution because the dispersed fossil fuel emissions would be replaced by radioactive wastes generated at large central stations. The conversion of internal or external combustion engines for combustion of hydrogen fuel would probably have less economic impact on the automotive industry than the mass introduction of electric automobiles. However, this is a subject that requires more detailed study. All of the safety aspects of hydrogen utilization will have to be examined, especially the problems of safety in the domestic use and the long distance transport of hydrogen in pipelines at high pressures. It is our opinion that the various energy planning agencies should now begin to outline the mode of implementing hydrogen energy delivery systems in the energy economy. The initial transition to hydrogen energy derived from available fossil fuels such as coal should be considered together with the long range view of all the hydrogen being derived eventually from nuclear energy. By the year 1985 when petroleum imports may be in excess of the domestic supply, these plans could set the stage for the transition period from fossil to a predominantly nuclear energy economy able to supply abundant synthetic fuels such as hydrogen. Synthetic fuels will obviously be more expensive than fuels now derived from petroleum; however, there may be no other viable choice. Thus, it is essential that the analysis and

Transfer Hydrogenation: Employing a Simple, In Situ Prepared Catalytic System

KAUST Repository

Ang, Eleanor Pei Ling

2017-04-01

Transfer hydrogenation has been recognized to be an important synthetic method in both academic and industrial research to obtain valuable products including alcohols. Transition metal catalysts based on precious metals, such as Ru, Rh and Ir, are typically employed for this process. In recent years, iron-based catalysts have attracted considerable attention as a greener and more sustainable alternative since iron is earth abundant, inexpensive and non-toxic. In this work, a combination of iron disulfide with chelating bipyridine ligand was found to be effective for the transfer hydrogenation of a variety of ketones to the corresponding alcohols in the presence of a simple base. It provided a convenient and economical way to conduct transfer hydrogenation. A plausible role of sulfide next to the metal center in facilitating the catalytic reaction is demonstrated.

Coherent dynamics of the localized vibrational modes of hydrogen in CaF2

NARCIS (Netherlands)

Wells, J. P. R.; Rella, C. W.; Bradley, I. V.; Galbraith, I.; Pidgeon, C. R.

2000-01-01

We report the observation of giant quantum coherence effects in the localized modes of ionized hydrogen in synthetic fluorite. Infrared free induction decay experiments on the substitutional H+ center thew dramatic modulations at negative delay times due to interference between multiple vibrational

Hydrogen and synthetic fuel production using pressurized solid oxide electrolysis cells

DEFF Research Database (Denmark)

Jensen, Søren Højgaard; Sun, Xiufu; Ebbesen, Sune

2010-01-01

Wind and solar power is troubled by large fluctuations in delivery due to changing weather. The surplus electricity can be used in a Solid Oxide Electrolyzer Cell (SOEC) to split CO2 + H2O into CO + H2 (+O2). The synthesis gas (CO + H2) can subsequently be catalyzed into various types of synthetic...... fuels using a suitable catalyst. As the catalyst operates at elevated pressure the fuel production system can be simplified by operating the SOEC at elevated pressure. Here we present the results of a cell test with pressures ranging from 0.4 bar to 10 bar. The cell was tested both as an SOEC...

Synthetic Biology Open Language (SBOL) Version 2.2.0.

Science.gov (United States)

Cox, Robert Sidney; Madsen, Curtis; McLaughlin, James Alastair; Nguyen, Tramy; Roehner, Nicholas; Bartley, Bryan; Beal, Jacob; Bissell, Michael; Choi, Kiri; Clancy, Kevin; Grünberg, Raik; Macklin, Chris; Misirli, Goksel; Oberortner, Ernst; Pocock, Matthew; Samineni, Meher; Zhang, Michael; Zhang, Zhen; Zundel, Zach; Gennari, John H; Myers, Chris; Sauro, Herbert; Wipat, Anil

2018-04-02

Synthetic biology builds upon the techniques and successes of genetics, molecular biology, and metabolic engineering by applying engineering principles to the design of biological systems. The field still faces substantial challenges, including long development times, high rates of failure, and poor reproducibility. One method to ameliorate these problems would be to improve the exchange of information about designed systems between laboratories. The synthetic biology open language (SBOL) has been developed as a standard to support the specification and exchange of biological design information in synthetic biology, filling a need not satisfied by other pre-existing standards. This document details version 2.2.0 of SBOL that builds upon version 2.1.0 published in last year's JIB special issue. In particular, SBOL 2.2.0 includes improved description and validation rules for genetic design provenance, an extension to support combinatorial genetic designs, a new class to add non-SBOL data as attachments, a new class for genetic design implementations, and a description of a methodology to describe the entire design-build-test-learn cycle within the SBOL data model.

Synthetic Biology Open Language (SBOL) Version 2.2.0

KAUST Repository

Cox, Robert Sidney

2018-04-04

Synthetic biology builds upon the techniques and successes of genetics, molecular biology, and metabolic engineering by applying engineering principles to the design of biological systems. The field still faces substantial challenges, including long development times, high rates of failure, and poor reproducibility. One method to ameliorate these problems would be to improve the exchange of information about designed systems between laboratories. The synthetic biology open language (SBOL) has been developed as a standard to support the specification and exchange of biological design information in synthetic biology, filling a need not satisfied by other pre-existing standards. This document details version 2.2.0 of SBOL that builds upon version 2.1.0 published in last year\\'s JIB special issue. In particular, SBOL 2.2.0 includes improved description and validation rules for genetic design provenance, an extension to support combinatorial genetic designs, a new class to add non-SBOL data as attachments, a new class for genetic design implementations, and a description of a methodology to describe the entire design-build-test-learn cycle within the SBOL data model.

Synthetic Biology Open Language (SBOL Version 2.2.0

Directory of Open Access Journals (Sweden)

Cox Robert Sidney

2018-04-01

Full Text Available Synthetic biology builds upon the techniques and successes of genetics, molecular biology, and metabolic engineering by applying engineering principles to the design of biological systems. The field still faces substantial challenges, including long development times, high rates of failure, and poor reproducibility. One method to ameliorate these problems would be to improve the exchange of information about designed systems between laboratories. The synthetic biology open language (SBOL has been developed as a standard to support the specification and exchange of biological design information in synthetic biology, filling a need not satisfied by other pre-existing standards. This document details version 2.2.0 of SBOL that builds upon version 2.1.0 published in last year’s JIB special issue. In particular, SBOL 2.2.0 includes improved description and validation rules for genetic design provenance, an extension to support combinatorial genetic designs, a new class to add non-SBOL data as attachments, a new class for genetic design implementations, and a description of a methodology to describe the entire design-build-test-learn cycle within the SBOL data model.

Synthetic Biology Open Language (SBOL) Version 2.2.0

KAUST Repository

Cox, Robert Sidney; Madsen, Curtis; McLaughlin, James Alastair; Nguyen, Tramy; Roehner, Nicholas; Bartley, Bryan; Beal, Jacob; Bissell, Michael; Choi, Kiri; Clancy, Kevin; Grunberg, Raik; Macklin, Chris; Misirli, Goksel; Oberortner, Ernst; Pocock, Matthew; Samineni, Meher; Zhang, Michael; Zhang, Zhen; Zundel, Zach; Gennari, John H.; Myers, Chris; Sauro, Herbert; Wipat, Anil

2018-01-01

Synthetic biology builds upon the techniques and successes of genetics, molecular biology, and metabolic engineering by applying engineering principles to the design of biological systems. The field still faces substantial challenges, including long development times, high rates of failure, and poor reproducibility. One method to ameliorate these problems would be to improve the exchange of information about designed systems between laboratories. The synthetic biology open language (SBOL) has been developed as a standard to support the specification and exchange of biological design information in synthetic biology, filling a need not satisfied by other pre-existing standards. This document details version 2.2.0 of SBOL that builds upon version 2.1.0 published in last year's JIB special issue. In particular, SBOL 2.2.0 includes improved description and validation rules for genetic design provenance, an extension to support combinatorial genetic designs, a new class to add non-SBOL data as attachments, a new class for genetic design implementations, and a description of a methodology to describe the entire design-build-test-learn cycle within the SBOL data model.

Natural - synthetic - artificial!

DEFF Research Database (Denmark)

Nielsen, Peter E

2010-01-01

The terms "natural," "synthetic" and "artificial" are discussed in relation to synthetic and artificial chromosomes and genomes, synthetic and artificial cells and artificial life.......The terms "natural," "synthetic" and "artificial" are discussed in relation to synthetic and artificial chromosomes and genomes, synthetic and artificial cells and artificial life....

Xylose fermentation to biofuels (hydrogen and ethanol) by extreme thermophilic (70 C) mixed culture

DEFF Research Database (Denmark)

Chenxi, Zhao; Karakashev, Dimitar Borisov; Lu, W.

2010-01-01

-xylose corresponding to 55% of the theoretical hydrogen yield based on acetate metabolic pathway. An empirical model was established to reveal the quantitative effect of factors significant for biohydrogen (quadratic model) production and for bioethanol (linear model) production. Changes in hydrogen/ethanol yields...

Energy metabolism in Desulfovibrio vulgaris Hildenborough: insights from transcriptome analysis

Energy Technology Data Exchange (ETDEWEB)

Pereira, Patricia M.; He, Qiang; Valente, Filipa M.A.; Xavier, Antonio V.; Zhou, Jizhong; Pereira, Ines A.C.; Louro, Ricardo O.

2007-11-01

Sulphate-reducing bacteria are important players in the global sulphur and carbon cycles, with considerable economical and ecological impact. However, the process of sulphate respiration is still incompletely understood. Several mechanisms of energy conservation have been proposed, but it is unclear how the different strategies contribute to the overall process. In order to obtain a deeper insight into the energy metabolism of sulphate-reducers whole-genome microarrays were used to compare the transcriptional response of Desulfovibrio vulgaris Hildenborough grown with hydrogen/sulphate, pyruvate/sulphate, pyruvate with limiting sulphate, and lactate/thiosulphate, relative to growth in lactate/sulphate. Growth with hydrogen/sulphate showed the largest number of differentially expressed genes and the largest changes in transcript levels. In this condition the most up-regulated energy metabolism genes were those coding for the periplasmic [NiFeSe]hydrogenase, followed by the Ech hydrogenase. The results also provide evidence for the involvement of formate cycling and the recently proposed ethanol pathway during growth in hydrogen. The pathway involving CO cycling is relevant during growth on lactate and pyruvate, but not during growth in hydrogen as the most down-regulated genes were those coding for the CO-induced hydrogenase. Growth on lactate/thiosulphate reveals a down-regulation of several energymetabolism genes similar to what was observed in the presence of nitrite. This study identifies the role of several proteins involved in the energy metabolism of D. vulgaris and highlights several novel genes related to this process, revealing a more complex bioenergetic metabolism than previously considered.

Microbial pathways in colonic sulfur metabolism and links with health and disease

Directory of Open Access Journals (Sweden)

Franck eCarbonero

2012-11-01

Full Text Available Sulfur is both crucial to life and a potential threat to health. While colonic sulfur metabolism mediated by eukaryotic cells is relatively well studied, much less is known about sulfur metabolism within gastrointestinal microbes. Sulfated compounds in the colon are either of inorganic (e.g., sulfates, sulfites or organic (e.g., dietary amino acids and host mucins origin. The most extensively studied of the microbes involved in colonic sulfur metabolism are the sulfate-reducing bacteria, which are common colonic inhabitants. Many other microbial pathways are likely to shape colonic sulfur metabolism as well as the composition and availability of sulfated compounds, and these interactions need to be examined in more detail. Hydrogen sulfide is the sulfur derivative that has attracted the most attention in the context of colonic health, and the extent to which it is detrimental or beneficial remains in debate. Several lines of evidence point to sulfate-reducing bacteria or exogenous hydrogen sulfide as potential players in the etiology of intestinal disorders, inflammatory bowel diseases and colorectal cancer in particular. Generation of hydrogen sulfide via pathways other than dissimilatory sulfate reduction may be as, or more, important than those involving the sulfate-reducing bacteria. We suggest here that a novel axis of research is to assess the effects of hydrogen sulfide in shaping colonic microbiome structure. Clearly, in-depth characterization of the microbial pathways involved in colonic sulfur metabolism is necessary for a better understanding of its contribution to colonic disorders and development of therapeutic strategies.

Prospects and technical and economic evaluation of methods for obtaining synthetic liquid from coal

Energy Technology Data Exchange (ETDEWEB)

Shlikhter, E B; Khor' kov, A V; Zhorov, Y M

1980-11-01

Rising oil prices and the exhaustion of cheap organic fuels point to the need for chemical processing of coal to obtain synthetic liquid fuels. Added importance for such development in the USSR is dictated by the remote location of many coal deposits, such as the Kansko-Achinsk basin. Methods for synthesizing described include thermal dissolution in a hydrogen donor solvent, hydrogenation, and gasification with subsequent synthesis and pyrolysis. The need for improved technology is stressed. Cost factors are related to the chemical process involved, rather than to losses in fuel quantities, and the methanol produced is readily transported by pipeline. It can be used for both gasoline and diesel fuels.

Strategies to distinguish new synthetic cannabinoid FUBIMINA (BIM-2201) intake from its isomer THJ-2201: metabolism of FUBIMINA in human hepatocytes.

Science.gov (United States)

Diao, Xingxing; Scheidweiler, Karl B; Wohlfarth, Ariane; Zhu, Mingshe; Pang, Shaokun; Huestis, Marilyn A

Since 2013, a new drugs-of-abuse trend attempts to bypass drug legislation by marketing isomers of scheduled synthetic cannabinoids (SCs), e.g., FUBIMINA (BIM-2201) and THJ-2201. It is much more challenging to confirm a specific isomer's intake and distinguish it from its structural analog because the isomers and their major metabolites usually have identical molecular weights and display the same product ions. Here, we investigated isomers FUBIMINA and THJ-2201 and propose strategies to distinguish their consumption. THJ-2201 was scheduled in the US, Japan, and Europe; however, FUBIMINA is easily available on the Internet. We previously investigated THJ-2201 metabolism in human hepatocytes, but human FUBIMINA metabolism is unknown. We aim to characterize FUBIMINA metabolism in human hepatocytes, recommend optimal metabolites to confirm its consumption, and propose strategies to distinguish between intakes of FUBIMINA and THJ-2201. FUBIMINA (10 μM) was incubated in human hepatocytes for 3 h, and metabolites were characterized with high-resolution mass spectrometry (HR-MS). We identified 35 metabolites generated by oxidative defluorination, further carboxylation, hydroxylation, dihydrodiol formation, glucuronidation, and their combinations. We recommend 5'-OH-BIM-018 (M34), BIM-018 pentanoic acid (M33), and BIM-018 pentanoic acid dihydrodiol (M7) as FUBIMINA specific metabolites. THJ-2201 produced specific metabolite markers 5'-OH-THJ-018 (F26), THJ-018 pentanoic acid (F25), and hydroxylated THJ-2201 (F13). Optimized chromatographic conditions to achieve different retention times and careful selection of specific product ion spectra enabled differentiation of isomeric metabolites, in this case FUBIMINA from THJ-2201. Our HR-MS approach should be applicable for differentiating future isomeric SCs, which is especially important when different isomers have different legal status.

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)

Characterization and metabolic synthetic lethal testing in a new model of SDH-loss familial pheochromocytoma and paraganglioma.

Science.gov (United States)

Smestad, John; Hamidi, Oksana; Wang, Lin; Holte, Molly Nelson; Khazal, Fatimah Al; Erber, Luke; Chen, Yue; Maher, L James

2018-01-19

Succinate dehydrogenase (SDH)-loss pheochromocytoma and paraganglioma (PPGL) are tumors driven by metabolic derangement. SDH loss leads to accumulation of intracellular succinate, which competitively inhibits dioxygenase enzymes, causing activation of pseudohypoxic signaling and hypermethylation of histones and DNA. The mechanisms by which these alterations lead to tumorigenesis are unclear, however. In an effort to fundamentally understand how SDH loss reprograms cell biology, we developed an immortalized mouse embryonic fibroblast cell line with conditional disruption of Sdhc and characterize the kinetics of Sdhc gene rearrangement, SDHC protein loss, succinate accumulation, and the resultant hypoproliferative phenotype. We further perform global transcriptomic, epigenomic, and proteomic characterization of changes resulting from SDHC loss, identifying specific perturbations at each biological level. We compare the observed patterns of epigenomic derangement to another previously-described immortalized mouse chromaffin cell model of SDHB loss, and compare both models to human SDH-loss tumors. Finally, we perform analysis of SDHC synthetic lethality with lactate dehydrogenase A (LDHA) and pyruvate carboxylase (PCX), which are important for regeneration of NAD+ and aspartate biosynthesis, respectively. Our data show that SDH-loss cells are selectively vulnerable to LDH genetic knock-down or chemical inhibition, suggesting that LDH inhibition may be an effective therapeutic strategy for SDH-loss PPGL.

Pathophysiological aspect of metabolic acid-base disorders

Directory of Open Access Journals (Sweden)

Nešović-Ostojić Jelena

2016-01-01

Full Text Available Maintaing the arterial pH values (in normal range of 7,35-7,45 is one of the main principles of homeostasis. Regulatory responses, including chemical buffering (extracellular, intracellular, sceletal, the regulation of pCO2 by the respiratory system, and the regulation of [HCO3-] by the kidneys, act in concert to maintain normal arterial pH value. The main extracellular chemical buffer is bicarbonate-carbonic acid buffer system. The kidneys contribute to the regulation of hydrogen (and bicarbonate in body fluids in two ways. Proximal tubules are important in bicarbonate reabsorption and distal tubules excrete hydrogen ion (as ammonium ion or titratable acid. There are four simple acid-base disorders: metabolic acidosis and metabolic alkalosis; respiratory acidosis and respiratory alkalosis. Metabolic acidosis can occur because of an increase in endogenous acid production (such as lactate and ketoacids, loss of bicarbonate (as in diarrhea, or accumulation of endogenous acids (as in renal failure. Metabolic acidosis can also be with high and normal (hyperchloremic metabolic acidosis anion gap. Renal tubular acidosis (RTA is a form of hyperchloremic metabolic acidosis which occurs when the renal damage primarily affects tubular function. The main problem in distal RTA is reduced H+ excretion in distal tubule. Type 2 RTA is also called proximal RTA because the main problem is greatly impaired reabsorption of bicarbonate in proximal tubule. Impaired cation exchange in distal tubule is the main problem in RTA type 4. Metabolic alkalosis occurs as a result of net gain of [HCO3-] or loss of nonvolatile acid from extracellular fluids. Metabolic alkalosis can be associated with reduced or increased extracellular volume.

Genome scale engineering techniques for metabolic engineering.

Science.gov (United States)

Liu, Rongming; Bassalo, Marcelo C; Zeitoun, Ramsey I; Gill, Ryan T

2015-11-01

Metabolic engineering has expanded from a focus on designs requiring a small number of genetic modifications to increasingly complex designs driven by advances in genome-scale engineering technologies. Metabolic engineering has been generally defined by the use of iterative cycles of rational genome modifications, strain analysis and characterization, and a synthesis step that fuels additional hypothesis generation. This cycle mirrors the Design-Build-Test-Learn cycle followed throughout various engineering fields that has recently become a defining aspect of synthetic biology. This review will attempt to summarize recent genome-scale design, build, test, and learn technologies and relate their use to a range of metabolic engineering applications. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Distinct pharmacology and metabolism of K2 synthetic cannabinoids compared to Δ9-THC: Mechanism underlying greater toxicity?

Science.gov (United States)

Fantegrossi, William E.; Moran, Jeffery H.; Radominska-Pandya, Anna; Prather, Paul L.

2013-01-01

K2 or Spice products are emerging drugs of abuse that contain synthetic cannabinoids (SCBs). Although assumed by many teens and first time drug users to be a “safe” and “legal” alternative to marijuana, many recent reports indicate that SCBs present in K2 produce toxicity not associated with the primary psychoactive component of marijuana, Δ9-tetrahydrocannabinol (Δ9-THC). This mini-review will summarize recent evidence that use of K2 products poses greater health risks relative to marijuana, and suggest that distinct pharmacological properties and metabolism of SCBs relative to Δ9-THC may contribute to the observed toxicity. Studies reviewed will indicate that in contrast to partial agonist properties of Δ9-THC typically observed in vitro, SCBs in K2 products act as full cannabinoid receptor type 1 (CB1R) and type 2 (CB2R) agonists in both cellular assays and animal studies. Furthermore, unlike Δ9-THC metabolism, several SCB metabolites retain high affinity for, and exhibit a range of intrinsic activities at, CB1 and CB2Rs. Finally, several reports indicate that although quasi-legal SCBs initially evaded detection and legal consequences, these presumed “advantages” have been limited by new legislation and development of product and human testing capabilities. Collectively, evidence reported in this mini-review suggests that K2 products are neither safe nor legal alternatives to marijuana. Instead, enhanced toxicity of K2 products relative to marijuana, perhaps resulting from the combined actions of a complex mixture of different SCBs present and their active metabolites that retain high affinity for CB1 and CB2Rs, highlights the inherent danger that may accompany use of these substances. PMID:24084047

Distinct pharmacology and metabolism of K2 synthetic cannabinoids compared to Δ(9)-THC: mechanism underlying greater toxicity?

Science.gov (United States)

Fantegrossi, William E; Moran, Jeffery H; Radominska-Pandya, Anna; Prather, Paul L

2014-02-27

K2 or Spice products are emerging drugs of abuse that contain synthetic cannabinoids (SCBs). Although assumed by many teens and first time drug users to be a "safe" and "legal" alternative to marijuana, many recent reports indicate that SCBs present in K2 produce toxicity not associated with the primary psychoactive component of marijuana, ∆(9)-tetrahydrocannabinol (Δ(9)-THC). This mini-review will summarize recent evidence that use of K2 products poses greater health risks relative to marijuana, and suggest that distinct pharmacological properties and metabolism of SCBs relative to Δ(9)-THC may contribute to the observed toxicity. Studies reviewed will indicate that in contrast to partial agonist properties of Δ(9)-THC typically observed in vitro, SCBs in K2 products act as full cannabinoid receptor type 1 (CB1R) and type 2 (CB2R) agonists in both cellular assays and animal studies. Furthermore, unlike Δ(9)-THC metabolism, several SCB metabolites retain high affinity for, and exhibit a range of intrinsic activities at, CB1 and CB2Rs. Finally, several reports indicate that although quasi-legal SCBs initially evaded detection and legal consequences, these presumed "advantages" have been limited by new legislation and development of product and human testing capabilities. Collectively, evidence reported in this mini-review suggests that K2 products are neither safe nor legal alternatives to marijuana. Instead, enhanced toxicity of K2 products relative to marijuana, perhaps resulting from the combined actions of a complex mixture of different SCBs present and their active metabolites that retain high affinity for CB1 and CB2Rs, highlights the inherent danger that may accompany use of these substances. © 2013.

Bio-hydrogen production by Enterobacter asburiae SNU-1 isolated from a landfill

Energy Technology Data Exchange (ETDEWEB)

Jong-Hwan Shin; Jong Hyun Yoon; Tai Hyun Park [School of Chemical and Biological Engineering, Seoul National University, Seoul 151-744, (Korea, Republic of)

2006-07-01

A new fermentative hydrogen-producing bacterium was isolated from a landfill, and it was identified as Enterobacter asburiae strain using a genomic DNA hybridization method. Environmental factors and metabolic flux influencing the hydrogen production were investigated, including pH, initial glucose and formate concentrations. The major hydrogen production pathway of this strain is considered to be a formate pathway by using formate hydrogen lyase (FHL). Optimum pH for the hydrogen production was pH 7.0 in PYG medium, at which hydrogen production/unit volume and overall hydrogen productivity were 2615 ml/l and 174 ml H{sub 2}/l/hr, respectively, at 25 g glucose/l. The maximum hydrogen productivity was estimated to be 417 ml H{sub 2}/l/hr at 15 g glucose/l. This strain produced bio-hydrogen mostly in the stationary phase, in which formate concentration was high. In this paper, hydrogen production was tried in formate medium after cell harvest. (authors)

Bio-hydrogen production by Enterobacter asburiae SNU-1 isolated from a landfill

International Nuclear Information System (INIS)

Jong-Hwan Shin; Jong Hyun Yoon; Tai Hyun Park

2006-01-01

A new fermentative hydrogen-producing bacterium was isolated from a landfill, and it was identified as Enterobacter asburiae strain using a genomic DNA hybridization method. Environmental factors and metabolic flux influencing the hydrogen production were investigated, including pH, initial glucose and formate concentrations. The major hydrogen production pathway of this strain is considered to be a formate pathway by using formate hydrogen lyase (FHL). Optimum pH for the hydrogen production was pH 7.0 in PYG medium, at which hydrogen production/unit volume and overall hydrogen productivity were 2615 ml/l and 174 ml H 2 /l/hr, respectively, at 25 g glucose/l. The maximum hydrogen productivity was estimated to be 417 ml H 2 /l/hr at 15 g glucose/l. This strain produced bio-hydrogen mostly in the stationary phase, in which formate concentration was high. In this paper, hydrogen production was tried in formate medium after cell harvest. (authors)

Expanding beyond canonical metabolism: Interfacing alternative elements, synthetic biology, and metabolic engineering

Directory of Open Access Journals (Sweden)

Kevin B. Reed

2018-03-01

Full Text Available Metabolic engineering offers an exquisite capacity to produce new molecules in a renewable manner. However, most industrial applications have focused on only a small subset of elements from the periodic table, centered around carbon biochemistry. This review aims to illustrate the expanse of chemical elements that can currently (and potentially be integrated into useful products using cellular systems. Specifically, we describe recent advances in expanding the cellular scope to include the halogens, selenium and the metalloids, and a variety of metal incorporations. These examples range from small molecules, heteroatom-linked uncommon elements, and natural products to biomining and nanotechnology applications. Collectively, this review covers the promise of an expanded range of elemental incorporations and the future impacts it may have on biotechnology.

Sublethal effects of manganese on the carbohydrate metabolism of ...

African Journals Online (AJOL)

Carbohydrate metabolism provides (1) energy,. (2) precursors for synthetic reactions ... as a response to the adrenal corticotrophic hormone (ACTH) from the ... During the exposure experiments, control groups were also set-up. The control fish ...

Biological hydrogen production from probiotic wastewater as substrate by selectively enriched anaerobic mixed microflora

Energy Technology Data Exchange (ETDEWEB)

Sivaramakrishna, D.; Sreekanth, D.; Himabindu, V. [Centre for Environment, Institute of Science and Technology, Jawaharlal Nehru Technological University, Kukatpally, Hyderabad 500072, Andhra Pradesh (India); Anjaneyulu, Y. [TLGVRC, JSU Box 18739, JSU, Jackson, MS 32917-0939 (United States)

2009-03-15

Biohydrogen production from probiotic wastewater using mixed anaerobic consortia is reported in this paper. Batch tests are carried out in a 5.0 L batch reactor under constant mesophillic temperature (37 C). The maximum hydrogen yield 1.8 mol-hydrogen/mol-carbohydrate is obtained at an optimum pH of 5.5 and substrate concentration 5 g/L. The maximum hydrogen production rate is 168 ml/h. The hydrogen content in the biogas is more than 65% and no significant methane is observed throughout the study. In addition to hydrogen, acetate, propionate, butyrate and ethanol are found to be the main by-products in the metabolism of hydrogen fermentation. (author)

Hydrogen solubility measurements of analyzed tall oil fractions and a solubility model

International Nuclear Information System (INIS)

Uusi-Kyyny, Petri; Pakkanen, Minna; Linnekoski, Juha; Alopaeus, Ville

2017-01-01

Highlights: • Hydrogen solubility was measured in four tall oil fractions between 373 and 597 K. • Continuous flow synthetic isothermal and isobaric method was used. • A Henry’s law model was developed for the distilled tall oil fractions. • The complex composition of the samples was analyzed and is presented. - Abstract: Knowledge of hydrogen solubility in tall oil fractions is important for designing hydrotreatment processes of these complex nonedible biobased materials. Unfortunately measurements of hydrogen solubility into these fractions are missing in the literature. This work reports hydrogen solubility measured in four tall oil fractions between 373 and 597 K and at pressures from 5 to 10 MPa. Three of the fractions were distilled tall oil fractions their resin acids contents are respectively 2, 20 and 23 in mass-%. Additionally one fraction was a crude tall oil (CTO) sample containing sterols as the main neutral fraction. Measurements were performed using a continuous flow synthetic isothermal and isobaric method based on the visual observation of the bubble point. Composition of the flow was changed step-wise for the bubble point composition determination. We assume that the tall oil fractions did not react during measurements, based on the composition analysis performed before and after the measurements. Additionally the densities of the fractions were measured at atmospheric pressure from 293.15 to 323.15 K. A Henry’s law model was developed for the distilled tall oil fractions describing the solubility with an absolute average deviation of 2.1%. Inputs of the solubility model are temperature, total pressure and the density of the oil at 323.15 K. The solubility of hydrogen in the CTO sample can be described with the developed model with an absolute average deviation of 3.4%. The solubility of hydrogen increases both with increasing pressure and/or increasing temperature. The more dense fractions of the tall oil exhibit lower hydrogen

Metabolic fate of lactoferricin-based antimicrobial peptides: effect of truncation and incorporation of amino acid analogs on the in vitro metabolic stability.

Science.gov (United States)

Svenson, Johan; Vergote, Valentijn; Karstad, Rasmus; Burvenich, Christian; Svendsen, John S; De Spiegeleer, Bart

2010-03-01

A series of promising truncated antibacterial tripeptides derived from lactoferricin has been prepared, and their in vitro metabolic stability in the main metabolic compartments, plasma, liver, kidney, stomach, duodenum, and brain, has been investigated for the first time. The potential stabilizing effect of truncation, C-terminal capping, and introduction of the bulky synthetic amino acid biphenylalanine is also investigated. The drug-like peptides displayed large differences in half-lives in the different matrixes ranging from 4.2 min in stomach and duodenum to 355.9 min in liver. Kinetic analysis of the metabolites revealed that several different degrading enzymes simultaneously target the different peptide bonds and that the outcome of the tested strategies to increase the stability is clearly enzyme-specific. Some of the metabolic enzymes even prefer the synthetic modifications incorporated over the natural counterparts. Collectively, it is shown that the necessary antibacterial pharmacophore generates compounds that are not only potent antibacterial peptides, but excellent substrates for the main degrading enzymes. All the amide bonds are thus rapidly targeted by different enzymes despite the short peptidic sequences of the tested compounds. Hence, our results illustrate that several structural changes are needed before these compounds can be considered for oral administration. Strategies to overcome such metabolic challenges are discussed.

Synthetic biology approaches to fluorinated polyketides.

Science.gov (United States)

Thuronyi, Benjamin W; Chang, Michelle C Y

2015-03-17

The catalytic diversity of living systems offers a broad range of opportunities for developing new methods to produce small molecule targets such as fuels, materials, and pharmaceuticals. In addition to providing cost-effective and renewable methods for large-scale commercial processes, the exploration of the unusual chemical phenotypes found in living organisms can also enable the expansion of chemical space for discovery of novel function by combining orthogonal attributes from both synthetic and biological chemistry. In this context, we have focused on the development of new fluorine chemistry using synthetic biology approaches. While fluorine has become an important feature in compounds of synthetic origin, the scope of biological fluorine chemistry in living systems is limited, with fewer than 20 organofluorine natural products identified to date. In order to expand the diversity of biosynthetically accessible organofluorines, we have begun to develop methods for the site-selective introduction of fluorine into complex natural products by engineering biosynthetic machinery to incorporate fluorinated building blocks. To gain insight into how both enzyme active sites and metabolic pathways can be evolved to manage and select for fluorinated compounds, we have studied one of the only characterized natural hosts for organofluorine biosynthesis, the soil microbe Streptomyces cattleya. This information provides a template for designing engineered organofluorine enzymes, pathways, and hosts and has allowed us to initiate construction of enzymatic and cellular pathways for the production of fluorinated polyketides.

Regulators of nonsulfur purple phototrophic bacteria and the interactive control of CO2 assimilation, nitrogen fixation, hydrogen metabolism and energy generation.

Science.gov (United States)

Dubbs, James M; Tabita, F Robert

2004-06-01

For the metabolically diverse nonsulfur purple phototrophic bacteria, maintaining redox homeostasis requires balancing the activities of energy supplying and energy-utilizing pathways, often in the face of drastic changes in environmental conditions. These organisms, members of the class Alphaproteobacteria, primarily use CO2 as an electron sink to achieve redox homeostasis. After noting the consequences of inactivating the capacity for CO2 reduction through the Calvin-Benson-Bassham (CBB) pathway, it was shown that the molecular control of many additional important biological processes catalyzed by nonsulfur purple bacteria is linked to expression of the CBB genes. Several regulator proteins are involved, with the two component Reg/Prr regulatory system playing a major role in maintaining redox poise in these organisms. Reg/Prr was shown to be a global regulator involved in the coordinate control of a number of metabolic processes including CO2 assimilation, nitrogen fixation, hydrogen metabolism and energy-generation pathways. Accumulating evidence suggests that the Reg/Prr system senses the oxidation/reduction state of the cell by monitoring a signal associated with electron transport. The response regulator RegA/PrrA activates or represses gene expression through direct interaction with target gene promoters where it often works in concert with other regulators that can be either global or specific. For the key CO2 reduction pathway, which clearly triggers whether other redox balancing mechanisms are employed, the ability to activate or inactivate the specific regulator CbbR is of paramount importance. From these studies, it is apparent that a detailed understanding of how diverse regulatory elements integrate and control metabolism will eventually be achieved.

Metabolic responses of Beauveria bassiana to hydrogen peroxide-induced oxidative stress using an LC-MS-based metabolomics approach.

Science.gov (United States)

Zhang, Chen; Wang, Wei; Lu, Ruili; Jin, Song; Chen, Yihui; Fan, Meizhen; Huang, Bo; Li, Zengzhi; Hu, Fenglin

2016-06-01

The entomopathogenic fungus, Beauveria bassiana, is commonly used as a biological agent for pest control. Environmental and biological factors expose the fungus to oxidative stress; as a result, B. bassiana has adopted a number of anti-oxidant mechanisms. In this study, we investigated metabolites of B. bassiana that are formed in response to oxidative stress from hydrogen peroxide (H2O2) by using a liquid chromatography mass spectrometry (LC-MS) approach. Partial least-squares discriminant analysis (PLS-DA) revealed differences between the control and the H2O2-treated groups. Hierarchical cluster analysis (HCA) showed 18 up-regulated metabolites and 25 down-regulated metabolites in the H2O2-treated fungus. Pathway analysis indicated that B. bassiana may be able to alleviate oxidative stress by enhancing lipid catabolism and glycometabolism, thus decreasing membrane polarity and preventing polar H2O2 or ROS from permeating into fungal cells and protecting cells against oxidative injury. Meanwhile, most of the unsaturated fatty acids that are derived from glycerophospholipids hydrolysis can convert into oxylipins through autoxidation, which can prevent the reactive oxygen of H2O2 from attacking important macromolecules of the fungus. Results showed also that H2O2 treatment can enhance mycotoxins production which implies that oxidative stress may be able to increase the virulence of the fungus. In comparison to the control group, citric acid and UDP-N-acetylglucosamine were down-regulated, which suggested that metabolic flux was occurring to the TCA cycle and enhancing carbohydrate metabolism. The findings from this study will contribute to the understanding of how the molecular mechanisms of fungus respond to environmental and biological stress factors as well as how the manipulation of such metabolisms may lead to selection of more effective fungal strains for pest control. Copyright © 2016 Elsevier Inc. All rights reserved.

Perspectives on New Synthetic Curcumin Analogs and their Potential Anticancer Properties

Science.gov (United States)

Vyas, Alok; Dandawate, Prasad; Padhye, Subhash; Ahmad, Aamir; Sarkar, Fazlul

2013-01-01

Curcumin is the active component of dried rhizome of Curcuma longa, a perennial herb belonging to ginger family, cultivated extensively in south and southeastern tropical Asia. It is widely consumed in the Indian subcontinent, south Asia and Japan in traditional food recipes. Extensive research over last few decades has shown that curcumin is a potent anti-inflammatory agent with powerful therapeutic potential against a variety of cancers. It suppresses proliferation and metastasis of human tumors through regulation of various transcription factors, growth factors, inflammatory cytokines, protein kinases and other enzymes. It induces apoptotic cell death and also inhibits proliferation of cancer cells by cell cycle arrest. Pharmacokinetic data has shown that curcumin undergoes rapid metabolism leading to glucuronidation and sulfation in the liver and excretion in the feces, which accounts for its poor systemic bioavailability. The compound has, therefore, been formulated and administered using different drug delivery systems such as liposomes, micelles, polysaccharides, phospholipid complexes and nanoparticles that can overcome the limitation of bioavailability to some extent. Attempts to avoid rapid metabolism of curcumin until now have been met with limited success. This has prompted researchers to look for new synthetic curcumin analogs in order to overcome the drawbacks of limited bioavailability and rapid metabolism, and gain efficacy with reduced toxicity. In this review we provide a summarized account of novel synthetic curcumin formulations and analogs, and the recent progress in the field of cancer prevention and treatment. PMID:23116312

A hydrogen economy - an answer to future energy problems

International Nuclear Information System (INIS)

Seifritz, W.

1975-01-01

''The Theme was THEME''. This was the headline of The Hydrogen Economy Miami Energy Conference which was the first international conference of this type and which took place in Miami, March 18-20, 1974. For the first time, about 700 participants from all over the western world discussed all the ramifications and aspects of a hydrogen based economy. Non-fossil hydrogen, produced from water by either electrolysis or by direct use of process heat from a nuclear source is a clean, all-synthetic, automatically recyclable, and inexhaustible fuel. It may support the World's future energy requirements beyond the present self limited fossil-fuel era. A large number of papers and news were presented on this conference reflecting this effort. The following article is intended to report on the highlights of the conference and to give a survey on the present state of the art in the hydrogen field. Furthermore, the author includes his own ideas and conclusions predominantly by taking into account the trends in the development of future nuclear reactor systems and symbiotic high-temperature-reactor/breeder strategies being the primary energy input of a hydrogen economy and providing a most promising avenue for solving both the World's energy and environmental (entropy) problems. (Auth.)

Precision control of recombinant gene transcription for CHO cell synthetic biology.

Science.gov (United States)

Brown, Adam J; James, David C

2016-01-01

The next generation of mammalian cell factories for biopharmaceutical production will be genetically engineered to possess both generic and product-specific manufacturing capabilities that may not exist naturally. Introduction of entirely new combinations of synthetic functions (e.g. novel metabolic or stress-response pathways), and retro-engineering of existing functional cell modules will drive disruptive change in cellular manufacturing performance. However, before we can apply the core concepts underpinning synthetic biology (design, build, test) to CHO cell engineering we must first develop practical and robust enabling technologies. Fundamentally, we will require the ability to precisely control the relative stoichiometry of numerous functional components we simultaneously introduce into the host cell factory. In this review we discuss how this can be achieved by design of engineered promoters that enable concerted control of recombinant gene transcription. We describe the specific mechanisms of transcriptional regulation that affect promoter function during bioproduction processes, and detail the highly-specific promoter design criteria that are required in the context of CHO cell engineering. The relative applicability of diverse promoter development strategies are discussed, including re-engineering of natural sequences, design of synthetic transcription factor-based systems, and construction of synthetic promoters. This review highlights the potential of promoter engineering to achieve precision transcriptional control for CHO cell synthetic biology. Copyright © 2015. Published by Elsevier Inc.

Suppression of atherosclerosis by synthetic REV-ERB agonist

Energy Technology Data Exchange (ETDEWEB)

Sitaula, Sadichha [Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458 (United States); Billon, Cyrielle [Department of Pharmacological & Physiological Science, Saint Louis University School of Medicine, St. Louis, MO 63104 (United States); Kamenecka, Theodore M.; Solt, Laura A. [Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458 (United States); Burris, Thomas P., E-mail: burristp@slu.edu [Department of Pharmacological & Physiological Science, Saint Louis University School of Medicine, St. Louis, MO 63104 (United States)

2015-05-08

The nuclear receptors for heme, REV-ERBα and REV-ERBβ, play important roles in the regulation of metabolism and inflammation. Recently it was demonstrated that reduced REV-ERBα expression in hematopoetic cells in LDL receptor null mice led to increased atherosclerosis. We sought to determine if synthetic REV-ERB agonists that we have developed might have the ability to suppress atherosclerosis in this model. A previously characterized synthetic REV-ERB agonist, SR9009, was used to determine if activation of REV-ERB activity would affect atherosclerosis in LDL receptor deficient mice. Atherosclerotic plaque size was significantly reduced (p < 0.05) in mice administered SR9009 (100 mg/kg) for seven weeks compared to control mice (n = 10 per group). SR9009 treatment of bone marrow-derived mouse macrophages (BMDM) reduced the polarization of BMDMs to proinflammatory M1 macrophage while increasing the polarization of BMDMs to anti-inflammatory M2 macrophages. Our results suggest that pharmacological targeting of REV-ERBs may be a viable therapeutic option for treatment of atherosclerosis. - Highlights: • Synthetic REV-ERB agonist treatment reduced atherosclerosis in a mouse model. • Pharmacological activation of REV-ERB decreased M1 macrophage polarization. • Pharmacological activation of REV-ERB increased M2 macrophage polarization.

Properties of alternative microbial hosts used in synthetic biology: towards the design of a modular chassis

Science.gov (United States)

Kim, Juhyun; Salvador, Manuel; Saunders, Elizabeth; González, Jaime; Avignone-Rossa, Claudio

2016-01-01

The chassis is the cellular host used as a recipient of engineered biological systems in synthetic biology. They are required to propagate the genetic information and to express the genes encoded in it. Despite being an essential element for the appropriate function of genetic circuits, the chassis is rarely considered in their design phase. Consequently, the circuits are transferred to model organisms commonly used in the laboratory, such as Escherichia coli, that may be suboptimal for a required function. In this review, we discuss some of the properties desirable in a versatile chassis and summarize some examples of alternative hosts for synthetic biology amenable for engineering. These properties include a suitable life style, a robust cell wall, good knowledge of its regulatory network as well as of the interplay of the host components with the exogenous circuits, and the possibility of developing whole-cell models and tuneable metabolic fluxes that could allow a better distribution of cellular resources (metabolites, ATP, nucleotides, amino acids, transcriptional and translational machinery). We highlight Pseudomonas putida, widely used in many different biotechnological applications as a prominent organism for synthetic biology due to its metabolic diversity, robustness and ease of manipulation. PMID:27903818

Synthetic Cannabinoids

Directory of Open Access Journals (Sweden)

Aslihan Okan Ibiloglu

2017-09-01

Full Text Available Synthetic cannabinoids which is a subgroup of cannabinoids are commonly used for recreational drug use throughout the whole world. Although both marijuana and synthetic cannabinoids stimulate the same receptors, cannabinoid receptor 1 (CB1 and cannabinoid receptor 2 (CB2, studies have shown that synthetic cannabinoids are much more potent than marijuana. The longer use of synthetic cannabinoids can cause severe physical and psychological symptoms that might even result in death, similar to many known illicit drugs. Main treatment options mostly involve symptom management and supportive care. The aim of this article is to discuss clinical and pharmacological properties of the increasingly used synthetic cannabinoids. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2017; 9(3.000: 317-328

Antibacterial Properties and Mechanism of Activity of a Novel Silver-Stabilized Hydrogen Peroxide.

Directory of Open Access Journals (Sweden)

Nancy L Martin

Full Text Available Huwa-San peroxide (hydrogen peroxide; HSP is a NSF Standard 60 (maximum 8 mg/L(-1 new generation peroxide stabilized with ionic silver suitable for continuous disinfection of potable water. Experiments were undertaken to examine the mechanism of HSP against planktonic and biofilm cultures of indicator bacterial strains. Contact/kill time (CT relationships that achieve effective control were explored to determine the potential utility in primary disinfection. Inhibitory assays were conducted using both nutrient rich media and a medium based on synthetic wastewater. Assays were compared for exposures to three disinfectants (HSP, laboratory grade hydrogen peroxide (HP and sodium hypochlorite at concentrations of 20 ppm (therefore at 2.5 and 5 times the NSF limit for HP and sodium hypochlorite, respectively and at pH 7.0 and 8.5 in dechlorinated tap water. HSP was found to be more or equally effective as hypochlorite or HP. Results from CT assays comparing HSP and HP at different bacterial concentrations with neutralization of residual peroxide with catalase suggested that at a high bacterial concentration HSP, but not HP, was protected from catalase degradation possibly through sequestration by bacterial cells. Consistent with this hypothesis, at a low bacterial cell density residual HSP was more effectively neutralized as less HSP was associated with bacteria and therefore accessible to catalase. Silver in HSP may facilitate this association through electrostatic interactions at the cell surface. This was supported by experiments where the addition of mono (K(+ and divalent (Ca(+2 cations (0.005-0.05M reduced the killing efficacy of HSP but not HP. Experiments designed to distinguish any inhibitory effect of silver from that of peroxide in HSP were carried out by monitoring the metabolic activity of established P. aeruginosa PAO1 biofilms. Concentrations of 70-500 ppm HSP had a pronounced effect on metabolic activity while the equivalent

The organellar genome and metabolic potential of the hydrogen- producing mitochondrion of Nyctotherus ovalis

NARCIS (Netherlands)

J.H.P. Hackstein (Johannes); C. Burgtorf; B.E. Dutilh (Bas); I. Duarte (Isabel); G.W.M. van der Staay (Georg); R.M. de Graaf (Rob); J.W.P. Kuiper (Jan); M. Huynen (Martijn); T.A. van Alen (Theo); G. Ricard (Guenola); A.G.M. Tielens (Aloysius)

2011-01-01

textabstractAbstract It is generally accepted that hydrogenosomes (hydrogen-producing organelles) evolved from a mitochondrial ancestor. However, until recently, only indirect evidence for this hypothesis was available. Here, we present the almost complete genome of the hydrogen-producing

Experiment Plan of High Temperature Steam and Carbon dioxide Co-electrolysis for Synthetic Gas Production

International Nuclear Information System (INIS)

Yoon, Duk-Joo; Ko, Jae-Hwa

2008-01-01

Currently, Solid oxide fuel cells (SOFC) come into the spotlight in the middle of the energy technologies of the future for highly effective conversion of fossil fuels into electricity without carbon dioxide emission. The SOFC is a reversible cell. By applying electrical power to the cell, which is solid oxide electrolysis cell (SOEC), it is possible to produce synthetic gas (syngas) from high temperature steam and carbon dioxide. The produced syngas (hydrogen and carbon monoxide) can be used for synthetic fuels. This SOEC technology can use high temperature from VHTRs for high efficiency. This paper describes KEPRI's experiment plan of high temperature steam and carbon co-electrolysis for syngas production using SOEC technology

Integrating biological redesign: where synthetic biology came from and where it needs to go.

Science.gov (United States)

Way, Jeffrey C; Collins, James J; Keasling, Jay D; Silver, Pamela A

2014-03-27

Synthetic biology seeks to extend approaches from engineering and computation to redesign of biology, with goals such as generating new chemicals, improving human health, and addressing environmental issues. Early on, several guiding principles of synthetic biology were articulated, including design according to specification, separation of design from fabrication, use of standardized biological parts and organisms, and abstraction. We review the utility of these principles over the past decade in light of the field's accomplishments in building complex systems based on microbial transcription and metabolism and describe the progress in mammalian cell engineering. Copyright © 2014 Elsevier Inc. All rights reserved.

Control of microbially generated hydrogen sulfide in produced waters

Energy Technology Data Exchange (ETDEWEB)

Burger, E.D.; Vance, I.; Gammack, G.F.; Duncan, S.E.

1995-12-31

Production of hydrogen sulfide in produced waters due to the activity of sulfate-reducing bacteria (SRB) is a potentially serious problem. The hydrogen sulfide is not only a safety and environmental concern, it also contributes to corrosion, solids formation, a reduction in produced oil and gas values, and limitations on water discharge. Waters produced from seawater-flooded reservoirs typically contain all of the nutrients required to support SRB metabolism. Surface processing facilities provide a favorable environment in which SRB flourish, converting water-borne nutrients into biomass and H{sub 2}S. This paper will present results from a field trial in which a new technology for the biochemical control of SRB metabolism was successfully applied. A slip stream of water downstream of separators on a produced water handling facility was routed through a bioreactor in a side-steam device where microbial growth was allowed to develop fully. This slip stream was then treated with slug doses of two forms of a proprietary, nonbiocidal metabolic modifier. Results indicated that H{sub 2}S production was halted almost immediately and that the residual effect of the treatment lasted for well over one week.

Redirection of Metabolic Hydrogen by Inhibiting Methanogenesis in the Rumen Simulation Technique (RUSITEC)

Science.gov (United States)

Guyader, Jessie; Ungerfeld, Emilio M.; Beauchemin, Karen A.

2017-01-01

A decrease in methanogenesis is expected to improve ruminant performance by allocating rumen metabolic hydrogen ([2H]) to more energy-rendering fermentation pathways for the animal. However, decreases in methane (CH4) emissions of up to 30% are not always linked with greater performance. Therefore, the aim of this study was to understand the fate of [2H] when CH4 production in the rumen is inhibited by known methanogenesis inhibitors (nitrate, NIT; 3-nitrooxypropanol, NOP; anthraquinone, AQ) in comparison with a control treatment (CON) with the Rumen Simulation Technique (RUSITEC). Measurements started after 1 week adaptation. Substrate disappearance was not modified by methanogenesis inhibitors. Nitrate mostly seemed to decrease [2H] availability by acting as an electron acceptor competing with methanogenesis. As a consequence, NIT decreased CH4 production (−75%), dissolved dihydrogen (H2) concentration (−30%) and the percentages of reduced volatile fatty acids (butyrate, isobutyrate, valerate, isovalerate, caproate and heptanoate) except propionate, but increased acetate molar percentage, ethanol concentration and the efficiency of microbial nitrogen synthesis (+14%) without affecting gaseous H2. Nitrooxypropanol decreased methanogenesis (−75%) while increasing both gaseous and dissolved H2 concentrations (+81% and +24%, respectively). Moreover, NOP decreased acetate and isovalerate molar percentages and increased butyrate, valerate, caproate and heptanoate molar percentages as well as n-propanol and ammonium concentrations. Methanogenesis inhibition with AQ (−26%) was associated with higher gaseous H2 production (+70%) but lower dissolved H2 concentration (−76%), evidencing a lack of relationship between the two H2 forms. Anthraquinone increased ammonium concentration, caproate and heptanoate molar percentages but decreased acetate and isobutyrate molar percentages, total microbial nitrogen production and efficiency of microbial protein synthesis (�

Hydrogen-Bonding Interactions Trigger a Spin-Flip in Iron(III) Porphyrin Complexes**

Science.gov (United States)

Sahoo, Dipankar; Quesne, Matthew G; de Visser, Sam P; Rath, Sankar Prasad

2015-01-01

A key step in cytochrome P450 catalysis includes the spin-state crossing from low spin to high spin upon substrate binding and subsequent reduction of the heme. Clearly, a weak perturbation in P450 enzymes triggers a spin-state crossing. However, the origin of the process whereby enzymes reorganize their active site through external perturbations, such as hydrogen bonding, is still poorly understood. We have thus studied the impact of hydrogen-bonding interactions on the electronic structure of a five-coordinate iron(III) octaethyltetraarylporphyrin chloride. The spin state of the metal was found to switch reversibly between high (S=5/2) and intermediate spin (S=3/2) with hydrogen bonding. Our study highlights the possible effects and importance of hydrogen-bonding interactions in heme proteins. This is the first example of a synthetic iron(III) complex that can reversibly change its spin state between a high and an intermediate state through weak external perturbations. PMID:26109743

Recent Progress Toward Hydrogen Medicine: Potential of Molecular Hydrogen for Preventive and Therapeutic Applications

Science.gov (United States)

Ohta, Shigeo

2011-01-01

Persistent oxidative stress is one of the major causes of most lifestyle-related diseases, cancer and the aging process. Acute oxidative stress directly causes serious damage to tissues. Despite the clinical importance of oxidative damage, antioxidants have been of limited therapeutic success. We have proposed that molecular hydrogen (H2) has potential as a “novel” antioxidant in preventive and therapeutic applications [Ohsawa et al., Nat Med. 2007: 13; 688-94]. H2 has a number of advantages as a potential antioxidant: H2 rapidly diffuses into tissues and cells, and it is mild enough neither to disturb metabolic redox reactions nor to affect reactive oxygen species (ROS) that function in cell signaling, thereby, there should be little adverse effects of consuming H2. There are several methods to ingest or consume H2, including inhaling hydrogen gas, drinking H2-dissolved water (hydrogen water), taking a hydrogen bath, injecting H2-dissolved saline (hydrogen saline), dropping hydrogen saline onto the eye, and increasing the production of intestinal H2 by bacteria. Since the publication of the first H2 paper in Nature Medicine in 2007, the biological effects of H2 have been confirmed by the publication of more than 38 diseases, physiological states and clinical tests in leading biological/medical journals, and several groups have started clinical examinations. Moreover, H2 shows not only effects against oxidative stress, but also various anti-inflammatory and anti-allergic effects. H2 regulates various gene expressions and protein-phosphorylations, though the molecular mechanisms underlying the marked effects of very small amounts of H2 remain elusive. PMID:21736547

The muscle protein synthetic response to food ingestion.

Science.gov (United States)

Gorissen, Stefan H M; Rémond, Didier; van Loon, Luc J C

2015-11-01

Preservation of skeletal muscle mass is of great importance for maintaining both metabolic health and functional capacity. Muscle mass maintenance is regulated by the balance between muscle protein breakdown and synthesis rates. Both muscle protein breakdown and synthesis rates have been shown to be highly responsive to physical activity and food intake. Food intake, and protein ingestion in particular, directly stimulates muscle protein synthesis rates. The postprandial muscle protein synthetic response to feeding is regulated on a number of levels, including dietary protein digestion and amino acid absorption, splanchnic amino acid retention, postprandial insulin release, skeletal muscle tissue perfusion, amino acid uptake by muscle, and intramyocellular signaling. The postprandial muscle protein synthetic response to feeding is blunted in many conditions characterized by skeletal muscle loss, such as aging and muscle disuse. Therefore, it is important to define food characteristics that modulate postprandial muscle protein synthesis. Previous work has shown that the muscle protein synthetic response to feeding can be modulated by changing the amount of protein ingested, the source of dietary protein, as well as the timing of protein consumption. Most of this work has studied the postprandial response to the ingestion of isolated protein sources. Only few studies have investigated the postprandial muscle protein synthetic response to the ingestion of protein dense foods, such as dairy and meat. The current review will focus on the capacity of proteins and protein dense food products to stimulate postprandial muscle protein synthesis and identifies food characteristics that may modulate the anabolic properties. Copyright © 2015 Elsevier Ltd. All rights reserved.

[From synthetic biology to synthetic humankind].

Science.gov (United States)

Nouvel, Pascal

2015-01-01

In this paper, we propose an historical survey of the expression "synthetic biology" in order to identify its main philosophical components. The result of the analysis is then used to investigate the meaning of the notion of "synthetic man". It is shown that both notions share a common philosophical background that can be summed up by the short but meaningful assertion: "biology is technology". The analysis allows us to distinguish two notions that are often confused in transhumanist literature: the notion of synthetic man and the notion of renewed man. The consequences of this crucial distinction are discussed. Copyright © 2015 Académie des sciences. Published by Elsevier SAS. All rights reserved.

Hydrogen cluster/network in tobermorite as studied by multiple-quantum spin counting {sup 1}H NMR

Energy Technology Data Exchange (ETDEWEB)

Mogami, Yuuki [Division of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502 (Japan); Yamazaki, Satoru; Matsuno, Shinya [Analysis and Simulation Center, Asahi Kasei Corporation, Fuji, Shizuoka 416-8501 (Japan); Matsui, Kunio [Products and Marketing Development Dept., Asahi Kasei Construction Materials Corporation, Sakai-machi, Ibaraki 306-0493 (Japan); Noda, Yasuto [Division of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502 (Japan); Takegoshi, K., E-mail: takeyan@kuchem.kyoto-u.ac.jp [Division of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502 (Japan)

2014-12-15

Proton multiple-quantum (MQ) spin-counting experiment has been employed to study arrangement of hydrogen atoms in 9 Å/11 Å natural/synthetic tobermorites. Even though all tobermorite samples give similar characterless, broad static-powder {sup 1}H NMR spectra, their MQ spin-counting spectra are markedly different; higher quanta in 11 Å tobermorite do not grow with the MQ excitation time, while those in 9 Å one do. A statistical analysis of the MQ results recently proposed [26] is applied to show that hydrogens align in 9 Å tobermorite one dimensionally, while in 11 Å tobermorite they exist as a cluster of 5–8 hydrogen atoms.

Renewable carbohydrates are a potential high-density hydrogen carrier

Energy Technology Data Exchange (ETDEWEB)

Zhang, Y.-H. Percival [Biological Systems Engineering Department, 210-A Seitz Hall, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States); Institute for Critical Technology and Applied Sciences (ICTAS), Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States); DOE BioEnergy Science Center (BESC), Oak Ridge, TN 37831 (United States)

2010-10-15

The possibility of using renewable biomass carbohydrates as a potential high-density hydrogen carrier is discussed here. Gravimetric density of polysaccharides is 14.8 H{sub 2} mass% where water can be recycled from PEM fuel cells or 8.33% H{sub 2} mass% without water recycling; volumetric densities of polysaccharides are >100 kg of H{sup 2}/m{sup 3}. Renewable carbohydrates (e.g., cellulosic materials and starch) are less expensive based on GJ than are other hydrogen carriers, such as hydrocarbons, biodiesel, methanol, ethanol, and ammonia. Biotransformation of carbohydrates to hydrogen by cell-free synthetic (enzymatic) pathway biotransformation (SyPaB) has numerous advantages, such as high product yield (12 H{sub 2}/glucose unit), 100% selectivity, high energy conversion efficiency (122%, based on combustion energy), high-purity hydrogen generated, mild reaction conditions, low-cost of bioreactor, few safety concerns, and nearly no toxicity hazards. Although SyPaB may suffer from current low reaction rates, numerous approaches for accelerating hydrogen production rates are proposed and discussed. Potential applications of carbohydrate-based hydrogen/electricity generation would include hydrogen bioreactors, home-size electricity generators, sugar batteries for portable electronics, sugar-powered passenger vehicles, and so on. Developments in thermostable enzymes as standardized building blocks for cell-free SyPaB projects, use of stable and low-cost biomimetic NAD cofactors, and accelerating reaction rates are among the top research and development priorities. International collaborations are urgently needed to solve the above obstacles within a short time. (author)

Morphological and metabolic changes in the nigro-striatal pathway of synthetic proteasome inhibitor (PSI-treated rats: a MRI and MRS study.

Directory of Open Access Journals (Sweden)

Stefano Delli Pizzi

Full Text Available Systemic administration of a Synthetic Proteasome Inhibitor (PSI in rats has been described as able to provide a model of Parkinson's disease (PD, characterized by behavioral and biochemical modifications, including loss of dopaminergic neurons in the substantia nigra (SN, as assessed by post-mortem studies. With the present study we aimed to assess in-vivo by Magnetic Resonance (MR possible morphological and metabolic changes in the nigro-striatal pathway of PSI-treated rats. 10 animals were subcutaneously injected with PSI 6.0 mg/kg dissolved in DMSO 100%. Injections were made thrice weekly over the course of two weeks. 5 more animals injected with DMSO 100% with the same protocol served as controls. The animals underwent MR sessions before and at four weeks after the end of treatment with either PSI or vehicle. MR Imaging was performed to measure SN volume and Proton MR Spectroscopy ((1H-MRS was performed to measure metabolites changes at the striatum. Animals were also assessed for motor function at baseline and at 4 and 6 weeks after treatment. Dopamine and dopamine metabolite levels were measured in the striata at 6 weeks after treatment. PSI-treated animals showed volumetric reduction of the SN (p<0.02 at 4 weeks after treatment as compared to baseline. Immunofluorescence analysis confirmed MRI changes in SN showing a reduction of tyrosine hydroxylase expression as compared to neuron-specific enolase expression. A reduction of N-acetyl-aspartate/total creatine ratio (p = 0.05 and an increase of glutamate-glutamine-γ amminobutirrate/total creatine were found at spectroscopy (p = 0.03. At 6 weeks after treatment, PSI-treated rats also showed motor dysfunction compared to baseline (p = 0.02, accompanied by dopamine level reduction in the striatum (p = 0.02. Treatment with PSI produced morphological and metabolic modifications of the nigro-striatal pathway, accompanied by motor dysfunction. MR demonstrated to be a powerful mean to assess in

Plant synthetic biology: a new platform for industrial biotechnology.

Science.gov (United States)

Fesenko, Elena; Edwards, Robert

2014-05-01

Thirty years after the production of the first generation of genetically modified plants we are now set to move into a new era of recombinant crop technology through the application of synthetic biology to engineer new and complex input and output traits. The use of synthetic biology technologies will represent more than incremental additions of transgenes, but rather the directed design of completely new metabolic pathways, physiological traits, and developmental control strategies. The need to enhance our ability to improve crops through new engineering capability is now increasingly pressing as we turn to plants not just for food, but as a source of renewable feedstocks for industry. These accelerating and diversifying demands for new output traits coincide with a need to reduce inputs and improve agricultural sustainability. Faced with such challenges, existing technologies will need to be supplemented with new and far-more-directed approaches to turn valuable resources more efficiently into usable agricultural products. While these objectives are challenging enough, the use of synthetic biology in crop improvement will face public acceptance issues as a legacy of genetically modified technologies in many countries. Here we review some of the potential benefits of adopting synthetic biology approaches in improving plant input and output traits for their use as industrial chemical feedstocks, as linked to the rapidly developing biorefining industry. Several promising technologies and biotechnological targets are identified along with some of the key regulatory and societal challenges in the safe and acceptable introduction of such technology.

Clinical findings and effect of sodium hydrogen carbonate in patients with glutathione synthetase deficiency.

Science.gov (United States)

Gündüz, Mehmet; Ünal, Özlem; Kavurt, Sumru; Türk, Emrecan; Mungan, Neslihan Önenli

2016-04-01

Glutathione synthetase (GS) deficiency is a rare inborn error of glutathione (GSH) metabolism manifested by severe metabolic acidosis, hemolytic anemia, neurological problems and massive excretion of pyroglutamic acid (5-oxoproline) in the urine. The disorder has mild, moderate, and severe clinical variants. We aimed to report clinical and laboratory findings of four patients, effect of sodium hydrogen carbonate treatment and long-term follow up of three patients. Urine organic acid analysis was performed with gas chromatography-mass spectrometry. Molecular genetic analysis was performed in three patients, mutation was found in two of them. Enzyme analysis was performed in one patient. Clinical and laboratory findings of four patients were evaluated. One patient died at 4 months old, one patient's growth and development are normal, two patients have developed intellectual disability and seizures in the long term follow up period. Three patients benefited from sodium hydrogen carbonate treatment. The clinical picture varies from patient to patient, so it is difficult to predict the prognosis and the effectiveness of treatment protocols. We reported long term follow up of four patients and demonstrated that sodium hydrogen carbonate is effective for treatment of chronic metabolic acidosis in GS deficieny.

Reward-based hypertension control by a synthetic brain-dopamine interface.

Science.gov (United States)

Rössger, Katrin; Charpin-El Hamri, Ghislaine; Fussenegger, Martin

2013-11-05

Synthetic biology has significantly advanced the design of synthetic trigger-controlled devices that can reprogram mammalian cells to interface with complex metabolic activities. In the brain, the neurotransmitter dopamine coordinates communication with target neurons via a set of dopamine receptors that control behavior associated with reward-driven learning. This dopamine transmission has recently been suggested to increase central sympathetic outflow, resulting in plasma dopamine levels that correlate with corresponding brain activities. By functionally rewiring the human dopamine receptor D1 (DRD1) via the second messenger cyclic adenosine monophosphate (cAMP) to synthetic promoters containing cAMP response element-binding protein 1(CREB1)-specific cAMP-responsive operator modules, we have designed a synthetic dopamine-sensitive transcription controller that reversibly fine-tunes specific target gene expression at physiologically relevant brain-derived plasma dopamine levels. Following implantation of circuit-transgenic human cell lines insulated by semipermeable immunoprotective microcontainers into mice, the designer device interfaced with dopamine-specific brain activities and produced a systemic expression response when the animal's reward system was stimulated by food, sexual arousal, or addictive drugs. Reward-triggered brain activities were able to remotely program peripheral therapeutic implants to produce sufficient amounts of the atrial natriuretic peptide, which reduced the blood pressure of hypertensive mice to the normal physiologic range. Seamless control of therapeutic transgenes by subconscious behavior may provide opportunities for treatment strategies of the future.

Process for producing synthetic ammonia gas. Verfahren zur Erzeugung von Ammoniak-Synthesegas

Energy Technology Data Exchange (ETDEWEB)

Meckel, J F; Messerschmidt, D; Wagener, D

1984-01-12

The invention refers to a process for producing synthetic ammonia gas from gases containing hydrocarbons, which is reformed catalytically and autothermally with a synthesis gas containing oxygen and then subjected to conversion to synthesis gas containing carbon dioxide and hydrogen. In order to simplify the plant required for such a process, the invention provides that part of the gas main flow is subjected to a multistage alternating pressure absorption plant (PSA plant) in a bypass of the gas main flow and the separated hydrogen is returned to the remaining gas main flow, in order to set the required H/sub 2/N/sub 2/ ratio and that the fission gas is subject to carbon dioxide washing and methanizing after conversion. This process therefore does not need a pipe splitting furnace and enrichment of the air with oxygen.

Storage of Renewable Energy by Reduction of CO2 with Hydrogen.

Science.gov (United States)

Züttel, Andreas; Mauron, Philippe; Kato, Shunsuke; Callini, Elsa; Holzer, Marco; Huang, Jianmei

2015-01-01

The main difference between the past energy economy during the industrialization period which was mainly based on mining of fossil fuels, e.g. coal, oil and methane and the future energy economy based on renewable energy is the requirement for storage of the energy fluxes. Renewable energy, except biomass, appears in time- and location-dependent energy fluxes as heat or electricity upon conversion. Storage and transport of energy requires a high energy density and has to be realized in a closed materials cycle. The hydrogen cycle, i.e. production of hydrogen from water by renewable energy, storage and use of hydrogen in fuel cells, combustion engines or turbines, is a closed cycle. However, the hydrogen density in a storage system is limited to 20 mass% and 150 kg/m(3) which limits the energy density to about half of the energy density in fossil fuels. Introducing CO(2) into the cycle and storing hydrogen by the reduction of CO(2) to hydrocarbons allows renewable energy to be converted into synthetic fuels with the same energy density as fossil fuels. The resulting cycle is a closed cycle (CO(2) neutral) if CO(2) is extracted from the atmosphere. Today's technology allows CO(2) to be reduced either by the Sabatier reaction to methane, by the reversed water gas shift reaction to CO and further reduction of CO by the Fischer-Tropsch synthesis (FTS) to hydrocarbons or over methanol to gasoline. The overall process can only be realized on a very large scale, because the large number of by-products of FTS requires the use of a refinery. Therefore, a well-controlled reaction to a specific product is required for the efficient conversion of renewable energy (electricity) into an easy to store liquid hydrocarbon (fuel). In order to realize a closed hydrocarbon cycle the two major challenges are to extract CO(2) from the atmosphere close to the thermodynamic limit and to reduce CO(2) with hydrogen in a controlled reaction to a specific hydrocarbon. Nanomaterials with

Efficient Synthesis of Functionalized 1-oxo-1-phenyl-2-acetic Acids through Ru(II)-catalyzed Transfer Hydrogenation

Energy Technology Data Exchange (ETDEWEB)

Wang, Xiaowei; Gong, Binwei; Meng, Yanqiu [Shenyang Univ. of Chemical Technology, Shenyang (Korea, Republic of); Yan, Yunnan [Gannan Medical Univ., Ganzhou (Korea, Republic of); Tang, Xiaobo; Eric Xu, H.; Yi, Wei [Chinese Academy of Sciences, Shanghai (China); Li, Qiu [Univ. of Science and Technology of China, Suzhou (China)

2013-10-15

A new and alternative method for the efficient synthesis of indanylacetic acid 2 has been developed. The methodology used RuCl(p-cymene)[(R,R)-TsDPEN] as the catalyst and formic acid-triethylamine as the hydrogen source at room temperature under solvent-free conditions, and the reactions have excellent chemoselectivity and good compatibility of substrates. Used our developed method as the starting step, gram scale synthesis of GR24 was achieved smoothly with an overall yield of 72%. All the results suggested that further development of such methodology may be of interest. Further work to establish the mechanistic reasons for selectivity and to further explore the synthetic scope of this mode of transfer hydrogenation is in progress. The synthetic SL analog, GR24 is a very potent germination stimulant, which is widely used in parasitic weed research to stimulate germination and as a standard for comparison of new germinating agents. Owing to the prevalence of GR24, its total synthesis constitutes a hot area of research. So far all known synthetic routes of GR24 used indanylacetic acid 2 as a key intermediate, for which very few methods of building compound 2 have been reported.

Photoproduction of hydrogen - A potential system of solar energy bioconversion

Energy Technology Data Exchange (ETDEWEB)

Das, V S.R.

1979-10-01

The photoproduction of hydrogen from water utilizing the photosynthetic capacity of green plants is discussed as a possible means of solar energy conversion. Advantages of the biological production of H/sub 2/ over various physical and chemical processes are pointed out, and the system used for the production of hydrogen by biological agents, which comprises the photosynthetic electron transport chain, ferredoxin and hydrogenase, is examined in detail. The various types of biological hydrogen production systems in bacteria, algae, symbiotic systems and isolated chloroplast-ferredoxin-hydrogenase systems are reviewed. The limitations and the scope for further improvement of the promising symbiotic Azolli-Anabena azollae and chloroplast-ferredoxin-hydrogenase are discussed, and it is concluded that future research should concern itself with the identification of the environmental conditions that would maximize solar energy conversion efficiency, the elimination of the oxygen inhibition of biological hydrogen production, and the definition of the metabolic state for the maximal production of hydrogen.

Design of spiral fin type condenser for hydrogen cryogenic distillation column

International Nuclear Information System (INIS)

Iwai, Yasunori; Nishi, Masataka; Yamanishi, Toshihiko

2005-08-01

The purpose of this paper is the proposal of new concept condenser for hydrogen cryogenic distillation column of Hydrogen Isotope Separation System (ISS) in a fusion reactor, and the establishment of numerical evaluation method of the hydrogen isotope inventory in the condenser. A large amount of hydrogen isotopes including high concentration of tritium, radioactive hydrogen isotope, has been handled in the cryogenic distillation column. Therefore, from the safety point of view, cryogenic coolant tube was commonly arranged to surround the condensed area to prevent the mixing of tritium into the coolant. This inevitable arrangement leads the difficulty in the minimization of the condenser. The scale of condenser has influence on the scale of the ISS and its earthquake-resistance. The spiral fin type condenser, which introduces fins inside it and in coolant tube to enhance heat exchange, is proposed as a new concept condenser for hydrogen cryogenic distillation column to miniaturize the condenser. The volume of spiral fin type condenser is estimated to become less than half of that of coil tube type condenser currently in use. Accordingly, it is found that the adoption of spiral fin type condenser realizes the significant miniaturization of the ISS. Moreover, the numerical evaluation method of the hydrogen isotope inventory in the condenser is proposed. The validity of this method was confirmed by the experimental data. The synthetic design of the condenser for the hydrogen cryogenic distillation column is achieved by the combination of the proposed new concept condenser with the numerical evaluation method of the hydrogen isotope inventory. (author)

Biocontainment of genetically modified organisms by synthetic protein design

Science.gov (United States)

Mandell, Daniel J.; Lajoie, Marc J.; Mee, Michael T.; Takeuchi, Ryo; Kuznetsov, Gleb; Norville, Julie E.; Gregg, Christopher J.; Stoddard, Barry L.; Church, George M.

2015-02-01

Genetically modified organisms (GMOs) are increasingly deployed at large scales and in open environments. Genetic biocontainment strategies are needed to prevent unintended proliferation of GMOs in natural ecosystems. Existing biocontainment methods are insufficient because they impose evolutionary pressure on the organism to eject the safeguard by spontaneous mutagenesis or horizontal gene transfer, or because they can be circumvented by environmentally available compounds. Here we computationally redesign essential enzymes in the first organism possessing an altered genetic code (Escherichia coli strain C321.ΔA) to confer metabolic dependence on non-standard amino acids for survival. The resulting GMOs cannot metabolically bypass their biocontainment mechanisms using known environmental compounds, and they exhibit unprecedented resistance to evolutionary escape through mutagenesis and horizontal gene transfer. This work provides a foundation for safer GMOs that are isolated from natural ecosystems by a reliance on synthetic metabolites.

Metabolism in the Uncultivated Giant Sulfide-Oxidizing Bacterium Thiomargarita Namibiensis Assayed Using a Redox-Sensitive Dye

Science.gov (United States)

Bailey, J.; Flood, B.; Ricci, E.

2014-12-01

The colorless sulfur bacteria are non-photosynthetic chemolithotrophs that live at interfaces between nitrate, or oxygen, and hydrogen sulfide. In sulfidic settings such as cold seeps and oxygen minimum zones, these bacteria are thought to constitute a critical node in the geochemical cycling of carbon, sulfur, nitrogen, and phosphorous. Many of these bacteria remain uncultivated and their metabolisms and physiologies are incompletely understood. Thiomargarita namibiensis is the largest of these sulfur bacteria, with individual cells reaching millimetric diameters. Despite the current inability to maintain a Thiomargarita culture in the lab, their large size allows for individual cells to be followed in time course experiments. Here we report on the novel use of a tetrazolium-based dye that measures the flux of NADH production from catabolic pathways via a colorimetric response. Staining with this dye allows for metabolism to be detected, even in the absence of observable cell division. When coupled to microscopy, this approach also allows for metabolism in Thiomargaritato be differentiated from that of epibionts or contaminants in xenic samples. The results of our tetrazolium dye-based assay suggests that Thiomargarita is the most metabolically versatile under anoxic conditions where it appears capable of using acetate, succinate, formate, thiosulfate, citrate, thiotaurine, hydrogen sulfide, and perhaps hydrogen as electron donors. Under hypoxic conditions, staining results suggest the utilization of acetate, citrate, and hydrogen sulfide. Cells incubated under oxic conditions showed the weakest tetrazolium staining response, and then only to hydrogen sulfide and questionably succinate. These initial results using a redox sensitive dye suggest that Thiomargarita is most metabolically versatile under anaerobic and hypoxic conditions. The results of this assay can be further evaluated using molecular approaches such as transcriptomics, as well as provide cultivation

Effect Of Substrates On The Fractionation Of Hydrogen Isotopes During Lipid-Biosynthesis By Haloarcula marismortui

Science.gov (United States)

Dirghangi, S. S.; Pagani, M.

2010-12-01

Lipids form an important class of proxies for paleoclimatological research, and hydrogen isotope ratios of lipids are being increasingly used for understanding changes in the hydrological system. Proper understanding of hydrogen isotope fractionation during lipid biosynthesis is therefore important and attention has been directed toward understanding the magnitude of hydrogen isotope fractionation that occurs during lipid biosynthesis in various organisms. Hydrogen isotope ratios of lipids depend on the hydrogen isotopic composition of the ambient water, hydrogen isotopic composition of NADPH used during biosynthesis, growth conditions, pathways of lipid biosynthesis, and substrates in the case of heterotrophic organisms. Recently it has been observed that NADPH contributes a significant part of the hydrogen in fatty acids synthesized by bacteria during heterotrophic growth (Zhang et al, 2009). As NADPH is formed by reduction of NADP+ during metabolism of substrates, different metabolic pathways form NADPH with different D/H ratios, which in turn results in variation in D/H ratios of lipids (Zhang et al, 2009). Therefore, substrates play a significant role in hydrogen isotopic compositions of lipids. For this study, we are investigating the effects of substrates on hydrogen isotope fractionation during biosynthesis of isoprenoidal lipids by heterotrophically growing halophilic archaea. Haloarcula marismortui is a halophilic archaea which synthesizes Archaeol (a diether lipid) and other isoprenoidal lipids. We have grown Haloarcula marismortui in pure cultures on three different substrates and are in the process of evaluating isotopic variability of Archaeol and other lipids associated with substrate and the D/H composition of ambient water. Our results will be helpful for a better understanding of hydrogen isotope fractionations during lipid synthesis by archaea. Also, halophilic archaea are the only source of archaeol in hypersaline environments. Therefore, our

The prospects of synthetic biology for the production of fuel from biomass

International Nuclear Information System (INIS)

Schaechter, V.

2013-01-01

When applied to engineering the metabolism of microorganisms, synthetic biology produces a broad spectrum of biomolecules from carbohydrates and, in the near future, from the biomass in general. The markets for biofuels and for chemicals are thus hooked up through a common technological core. Synthetic biology also opens new possibilities for switching from different types of biomass to different products, thus allowing for more flexibility in development strategies and eventually in industrial operations. This opening is welcomed even though the economic and societal environments hardly favors biofuels. A few more years of research and development are needed to bring these new possibilities to industrial maturity. Advanced biofuels will pass the threshold at which they become profitable and will no longer need subsidies. (author)

Recent advances in systems metabolic engineering tools and strategies.

Science.gov (United States)

Chae, Tong Un; Choi, So Young; Kim, Je Woong; Ko, Yoo-Sung; Lee, Sang Yup

2017-10-01

Metabolic engineering has been playing increasingly important roles in developing microbial cell factories for the production of various chemicals and materials to achieve sustainable chemical industry. Nowadays, many tools and strategies are available for performing systems metabolic engineering that allows systems-level metabolic engineering in more sophisticated and diverse ways by adopting rapidly advancing methodologies and tools of systems biology, synthetic biology and evolutionary engineering. As an outcome, development of more efficient microbial cell factories has become possible. Here, we review recent advances in systems metabolic engineering tools and strategies together with accompanying application examples. In addition, we describe how these tools and strategies work together in simultaneous and synergistic ways to develop novel microbial cell factories. Copyright © 2017 Elsevier Ltd. All rights reserved.

Human Cytomegalovirus: Coordinating Cellular Stress, Signaling, and Metabolic Pathways.

Science.gov (United States)

Shenk, Thomas; Alwine, James C

2014-11-01

Viruses face a multitude of challenges when they infect a host cell. Cells have evolved innate defenses to protect against pathogens, and an infecting virus may induce a stress response that antagonizes viral replication. Further, the metabolic, oxidative, and cell cycle state may not be conducive to the viral infection. But viruses are fabulous manipulators, inducing host cells to use their own characteristic mechanisms and pathways to provide what the virus needs. This article centers on the manipulation of host cell metabolism by human cytomegalovirus (HCMV). We review the features of the metabolic program instituted by the virus, discuss the mechanisms underlying these dramatic metabolic changes, and consider how the altered program creates a synthetic milieu that favors efficient HCMV replication and spread.

Cell-Free Synthetic Biology Chassis for Nanocatalytic Photon-to-Hydrogen Conversion.

Science.gov (United States)

Wang, Peng; Chang, Angela Y; Novosad, Valentyn; Chupin, Vladimir V; Schaller, Richard D; Rozhkova, Elena A

2017-07-25

We report on an entirely man-made nano-bio architecture fabricated through noncovalent assembly of a cell-free expressed transmembrane proton pump and TiO 2 semiconductor nanoparticles as an efficient nanophotocatalyst for H 2 evolution. The system produces hydrogen at a turnover of about 240 μmol of H 2 (μmol protein) -1 h -1 and 17.74 mmol of H 2 (μmol protein) -1 h -1 under monochromatic green and white light, respectively, at ambient conditions, in water at neutral pH and room temperature, with methanol as a sacrificial electron donor. Robustness and flexibility of this approach allow for systemic manipulation at the nanoparticle-bio interface toward directed evolution of energy transformation materials and artificial systems.

Acute Intoxications Involving Synthetic Psychoactive Substances

Directory of Open Access Journals (Sweden)

Sergey A. Vasil'ev

2018-01-01

Full Text Available The purpose of this study was to evaluate the effectiveness of a succinic acid derivate, a substrate metabolic agent cytoflavin in patients with acute poisoning with synthetic psychoactive drugs.Materials and methods. A retrospective evaluation of effectiveness of a combined intensive care treatment protocol for 622 patients with acute narcotic poisoning (methadone and synthetic cannabinoids was carried out. All patients were divided into two groups. The main group (112 patients, median age 38.2±12.0 years included patients who, in addition to the basic treatment, received cytoflavin by intravenous drop infusion, 20–40 ml diluted in 400–500 ml of 10% glucose, for 5 days. Patients of the reference group (510 subjects, median age 37.6±14.1 years received treatment according to the «classical scheme». In addition to conventional examination, all patients underwent duplex scanning of cerebral vessels, examination of changes in the cerebral blood circulation and electroencephalogram findings. The severity of somatic disorders was assessed using criteria of the Glasgow coma scale. The severity of the asthenic syndrome was assessed according to the MFI-20 scale.Results. Compared to patients who received a standard therapy, patients of the main group had a significantly more rapid recovery from coma (by 1.5-fold: 23.5±3.1 days, versus 15.1±3.0 days, respectively, P0.05; the duration of psychotic disorders was shorter (by 1.8-fold: 15.5±4.2 hours vs 8.3±2.5 hours., respectively, P0.05, and the intensity of asthenic syndrome (by 2.8-fold: 64.1±3.3 rel. units vs 23.0±4,9 rel. units, respectively, P0.05 was also lower.Conclusion. Inclusion of cytoflavin in a protocol of a complex treatment of patients with synthetic drugs poisoning increased the effectiveness of the therapy. Data demonstrate that inclusion of the drug can be recommended for treatment of acute synthetic narcotic poisoning. 

Reaction mechanism of coal liquefaction: hydrogenolysis of model compound using synthetic pyrite as catalysts. 7. Property change of synthetic pyrite catalyst with the time after production; Sekitan ekika hanno kiko (model kagobutsu no hanno). 7. Gosei ryukatetsu shokubai no keiji henka ni tsuite

Energy Technology Data Exchange (ETDEWEB)

Ito, H.; Meno, H.; Uemaki, O.; Shibata, T.; Tsuji, T. [Hokkaido University, Sapporo (Japan)

1996-10-28

Reactions of various model compounds were investigated using synthetic pyrites for coal liquefaction. In this study, successive changes of the catalysts were investigated from the reactions of model compounds by using three different synthetic pyrites with the lapse of time after production. Benzyl phenyl ether, dibenzyl, and n-octylbenzene were used as model compounds. Reactions were conducted in an autoclave, into which sample, catalyst, decalin as solvent, and initial hydrogen pressure 10 MPa were charged. The autoclave was held at 450 or 475{degree}C of reaction temperature for 1 hour. The catalyst with a shorter lapse of time after production acted to hydrogen transfer, and inhibited the formation of condensation products due to the stabilization of decomposed fragment. It also acted to isomerization of materials by cutting alkyl side chains. When adding sulfur to the catalyst with longer lapse of time after production under these reaction conditions, it inhibited the formation of condensation products for the reaction of benzyl phenyl ether. However, it did not provide the effect for the reaction of n-octylbenzene. 5 refs., 3 figs.

Stereoselective hydrogenation of olefins using rhodium-substituted carbonic anhydrase--a new reductase.

Science.gov (United States)

Jing, Qing; Okrasa, Krzysztof; Kazlauskas, Romas J

2009-01-01

One useful synthetic reaction missing from nature's toolbox is the direct hydrogenation of substrates using hydrogen. Instead nature uses cofactors like NADH to reduce organic substrates, which adds complexity and cost to these reductions. To create an enzyme that can directly reduce organic substrates with hydrogen, researchers have combined metal hydrogenation catalysts with proteins. One approach is an indirect link where a ligand is linked to a protein and the metal binds to the ligand. Another approach is direct linking of the metal to protein, but nonspecific binding of the metal limits this approach. Herein, we report a direct hydrogenation of olefins catalyzed by rhodium(I) bound to carbonic anhydrase (CA-[Rh]). We minimized nonspecific binding of rhodium by replacing histidine residues on the protein surface using site-directed mutagenesis or by chemically modifying the histidine residues. Hydrogenation catalyzed by CA-[Rh] is slightly slower than for uncomplexed rhodium(I), but the protein environment induces stereoselectivity favoring cis- over trans-stilbene by about 20:1. This enzyme is the first cofactor-independent reductase that reduces organic molecules using hydrogen. This catalyst is a good starting point to create variants with tailored reactivity and selectivity. This strategy to insert transition metals in the active site of metalloenzymes opens opportunities to a wider range of enzyme-catalyzed reactions.

Diversified glucosinolate metabolism: biosynthesis of hydrogen cyanide and of the hydroxynitrile glucoside alliarinoside in relation to sinigrin metabolism in Alliaria petiolata

Directory of Open Access Journals (Sweden)

Tina eFrisch

2015-10-01

Full Text Available Alliaria petiolata (garlic mustard, Brassicaceae contains the glucosinolate sinigrin as well as alliarinoside, a γ-hydroxynitrile glucoside structurally related to cyanogenic glucosides. sinigrin may defend this plant against a broad range of enemies, while alliarinoside confers resistance to specialized (glucosinolate-adapted herbivores. Hydroxynitrile glucosides and glucosinolates are two classes of specialized metabolites, which generally do not occur in the same plant species. Administration of [UL-14C]-methionine to excised leaves of A. petiolata showed that both alliarinoside and sinigrin were biosynthesized from methionine. The biosynthesis of alliarinoside was shown not to bifurcate from sinigrin biosynthesis at the oxime level in contrast to the general scheme for hydroxynitrile glucoside biosynthesis. Instead, the aglucon of alliarinoside was formed from metabolism of sinigrin in experiments with crude extracts, suggesting a possible biosynthetic pathway in intact cells. Hence, the alliarinoside pathway may represent a route to hydroxynitrile glucoside biosynthesis resulting from convergent evolution. Metabolite profiling by LC-MS showed no evidence of the presence of cyanogenic glucosides in A. petiolata. However, we detected hydrogen cyanide (HCN release from sinigrin and added thiocyanate ion and benzyl thiocyanate in A. petiolata indicating an enzymatic pathway from glucosinolates via allyl thiocyanate and indole glucosinolate derived thiocyanate ion to HCN. Alliarinoside biosynthesis and HCN release from glucosinolate-derived metabolites expand the range of glucosinolate-related defences and can be viewed as a third line of defence, with glucosinolates and thiocyanate forming protein being the first and second lines, respectively.

Saga of hydrogen civilization

Energy Technology Data Exchange (ETDEWEB)

Veziroglu, T.N. [Univ. of Miami, Coral Gables, FL (United States). Clean Energy Research Institute

2008-09-30

the problem, it became clear that it would be necessary to manufacture a synthetic fuel using the new primary energy sources. Hydrogen is the lightest, the most efficient, the cleanest, and the best fuel for transportation. The resulting energy system was called 'Hydrogen Energy System' or 'Hydrogen Economy', since energy is the locomotive of economy. The author was quite sure this was the best solution to the depletion of fossil fuels and the global environmental problems they are causing, such as global warming, climate change, ozone layer depletion, acid rain, air pollution, oil spills, etc. In order to inform the scientific community about the proposed solution and get their reaction and input, the author organized an international conference named The Hydrogen Economy Miami Energy (THEME) Conference which opened on March 18, 1974 with the participation of more than 700 scientists from some eighty countries. By the end of 1974, the International Association for Hydrogen Energy (IAHE) was established. As a result of the research and development activities around the world, World Hydrogen Energy Conferences, and the publication and dissemination of the research and development results through the International Journal of Hydrogen Energy, foundations of the Hydrogen Energy System were established during the quarter century from 1974 to 2000. Starting with the twenty-first century, the implementation of the Hydrogen Energy System began. Some hydrogen fuel cells became commercially available. All major car companies came up with various models of experimental hydrogen-fuelled cars. In several major cities of the world, hydrogen-fuelled buses started being operated on a trial basis. Airbus and Boeing Companies started programs for building hydrogen fuelled subsonic, supersonic and hypersonic passenger planes. Home appliances running on hydrogen have been built and tested. Hydrogen electric batteries have been commercialized. At CERI, a model study

Mapping the Emergence of Synthetic Biology.

Directory of Open Access Journals (Sweden)

Benjamin Raimbault

Full Text Available In this paper, we apply an original scientometric analyses to a corpus comprising synthetic biology (SynBio publications in Thomson Reuters Web of Science to characterize the emergence of this new scientific field. Three results were drawn from this empirical investigation. First, despite the exponential growth of publications, the study of population level statistics (newcomers proportion, collaboration network structure shows that SynBio has entered a stabilization process since 2010. Second, the mapping of textual and citational networks shows that SynBio is characterized by high heterogeneity and four different approaches: the central approach, where biobrick engineering is the most widespread; genome engineering; protocell creation; and metabolic engineering. We suggest that synthetic biology acts as an umbrella term allowing for the mobilization of resources, and also serves to relate scientific content and promises of applications. Third, we observed a strong intertwinement between epistemic and socio-economic dynamics. Measuring scientific production and impact and using structural analysis data, we identified a core set of mostly American scientists. Biographical analysis shows that these central and influential scientists act as "boundary spanners," meaning that their importance to the field lies not only in their academic contributions, but also in their capacity to interact with other social spaces that are outside the academic sphere.

Two-Scale 13C Metabolic Flux Analysis for Metabolic Engineering.

Science.gov (United States)

Ando, David; Garcia Martin, Hector

2018-01-01

Accelerating the Design-Build-Test-Learn (DBTL) cycle in synthetic biology is critical to achieving rapid and facile bioengineering of organisms for the production of, e.g., biofuels and other chemicals. The Learn phase involves using data obtained from the Test phase to inform the next Design phase. As part of the Learn phase, mathematical models of metabolic fluxes give a mechanistic level of comprehension to cellular metabolism, isolating the principle drivers of metabolic behavior from the peripheral ones, and directing future experimental designs and engineering methodologies. Furthermore, the measurement of intracellular metabolic fluxes is specifically noteworthy as providing a rapid and easy-to-understand picture of how carbon and energy flow throughout the cell. Here, we present a detailed guide to performing metabolic flux analysis in the Learn phase of the DBTL cycle, where we show how one can take the isotope labeling data from a 13 C labeling experiment and immediately turn it into a determination of cellular fluxes that points in the direction of genetic engineering strategies that will advance the metabolic engineering process.For our modeling purposes we use the Joint BioEnergy Institute (JBEI) Quantitative Metabolic Modeling (jQMM) library, which provides an open-source, python-based framework for modeling internal metabolic fluxes and making actionable predictions on how to modify cellular metabolism for specific bioengineering goals. It presents a complete toolbox for performing different types of flux analysis such as Flux Balance Analysis, 13 C Metabolic Flux Analysis, and it introduces the capability to use 13 C labeling experimental data to constrain comprehensive genome-scale models through a technique called two-scale 13 C Metabolic Flux Analysis (2S- 13 C MFA) [1]. In addition to several other capabilities, the jQMM is also able to predict the effects of knockouts using the MoMA and ROOM methodologies. The use of the jQMM library is

Symbolic Analysis of the Cycle-to-Cycle Variability of a Gasoline–Hydrogen Fueled Spark Engine Model

Directory of Open Access Journals (Sweden)

Israel Reyes-Ramírez

2018-04-01

Full Text Available An study of temporal organization of the cycle-to-cycle variability (CCV in spark ignition engines fueled with gasoline–hydrogen blends is presented. First, long time series are generated by means of a quasi-dimensional model incorporating the key chemical and physical components, leading to variability in the time evolution of energetic functions. The alterations in the combustion process, for instance the composition of reactants, may lead to quantitative changes in the time evolution of the main engine variables. It has been observed that the presence of hydrogen in the fuel mixture leads to an increased laminar flame speed, with a corresponding decrease in CCV dispersion. Here, the effects of different hydrogen concentrations in the fuel are considered. First, it is observed that return maps of heat release sequences exhibit different patterns for different hydrogen concentrations and fuel–air ratios. Second, a symbolic analysis is used to characterize time series. The symbolic method is based on the probability of occurrence of consecutive states (a word in a symbolic sequence histogram (SSH. Modified Shannon entropy is computed in order to determine the adequate word length. Results reveal the presence of non-random patterns in the sequences and soft transitions between states. Moreover, the general behavior of CCV simulations results and three types of synthetic noises: white, log-normal, and a noisy logistic map, are compared. This analysis reveals that the non-random features observed in heat release sequences are quite different from synthetic noises.

Salicylic Acid Alters Antioxidant and Phenolics Metabolism in ...

African Journals Online (AJOL)

Key words: Antioxidant enzymes; Catharanthus roseus; indole alkaloids; phenolic metabolism; salicylic acid; salinity stress. Abbreviations: CAT - catalase; Chl - chlorophyll; Car - carotenoids; DTNB - 5,5-dithiobis-2-nitrobenzoic acid; GR - glutathione reductase; GST - Glutathione-S-transferase; H2O2 - hydrogen peroxide; ...

Storage of hydrogen and the problems it involves

Energy Technology Data Exchange (ETDEWEB)

Schmitt, R; Jonville, P

1975-01-01

The limitation of fossil fuel resources has brought about active research in the field of synthetic fuels which, in the more or less near future, could lead to freedom from dependence on production of the former. On a long-term basis, hydrogen would appear to be the best candidate as a substitute for conventional fuels. Among the possibilities of storage in a motor vehicle, its absorption in a metallic hydride provides the most attractive solution. Account taken of the weight limitations of this storage method, the use of hydrogen in an internal combustion engine can be envisaged only for short-range urban vehicles. Optimal use of its energy content will be made possible by means of fuel cells. The development of such a storage-propulsion chain nevertheless requires considerable work in research and development, both for the study of hydrides and the technology of fuel cells.

Degradation of 2,4,6-Trichlorophenol and hydrogen production simultaneously by TiO2 nanotubes/graphene composite

Science.gov (United States)

Slamet, Raudina

2017-11-01

Industrial waters in coal pyrolysis process, synthetic chemicals and oil and gas process contain phenol derivatives that are dangerous to the environment and needs to be removed, one of them is 2,4,6-Trichlorophenol. Degradation of 2,4,6-Trichlorophenol and hydrogen production simultaneously have been investigated using TiNT/Graphene composite at various graphene loading and initial concentration of 2,4,6-Trichlorophenol. Optimal graphene loading of 0.6 wt% was obtained in the simultaneous system with 89% elimination of 2,4,6-Trichlorophenol and 986 µmol of hydrogen production. Test results showed that addition of 2,4,6-Trichlorophenol would subsequently increased 2,4,6-Trichlorophenol conversion and enhanced hydrogen production linearly. 2.7 times greater hydrogen production was found in addition of 50 ppm 2,4,6-Trichlorophenol.

Hydrogen storage in Earth's mantle and core

Science.gov (United States)

Prewitt, Charles T.

1994-01-01

Two different approaches to explaining how hydrogen might be stored in the mantle are illustrated by a number of papers published over the past 25-30 years, but there has been little attempt to provide objective comparisons of the two. One approach invokes the presence in the mantle of dense hydrous magnesium silicates (DHMS) stable at elevated pressures and temperatures. The other involves nominally anhydrous minerals (NAM) that contain hydrogen as a minor constituent on the ppm level. Experimental studies on DHMS indicate these phases may be stable to pressures and temperatures as high at 16 GPa and 1200 C. This temperature is lower than that indicated by a mantle geotherm at 16 GPa, but may be reasonable for a subducting slab. It is possible that other DHMS could be stable to even higher pressures, but little is known about maximum temperature limits. For NAM, small amounts of hydrogen (up to several hundred ppm) have been detected in olivine, orthopyroxene, clinopyroxene, and garnet recovered from xenoliths in kimberlites, eclogites, and alkali basalts; it has been demonstrated that synthetic wadsleyite and perovskite can accommodate significant amounts of hydrogen. A number of problems are associated with each possibility. For NAM originating in the mantle, one would like to assume that the hydrogen measured in samples recovered on Earth's surface was incorporated when the phase-crystallized at high temperatures and pressures, but it could have been introduced during transport to the surface. Major problems for the DHMS proponents are that none of these phases have been found as minerals and little is yet known about their stabilities in systems containing other cations such as Fe, Al, and Ca.

Application of synthetic biology for production of chemicals in yeast Saccharomyces cerevisiae.

Science.gov (United States)

Li, Mingji; Borodina, Irina

2015-02-01

Synthetic biology and metabolic engineering enable generation of novel cell factories that efficiently convert renewable feedstocks into biofuels, bulk, and fine chemicals, thus creating the basis for biosustainable economy independent on fossil resources. While over a hundred proof-of-concept chemicals have been made in yeast, only a very small fraction of those has reached commercial-scale production so far. The limiting factor is the high research cost associated with the development of a robust cell factory that can produce the desired chemical at high titer, rate, and yield. Synthetic biology has the potential to bring down this cost by improving our ability to predictably engineer biological systems. This review highlights synthetic biology applications for design, assembly, and optimization of non-native biochemical pathways in baker's yeast Saccharomyces cerevisiae We describe computational tools for the prediction of biochemical pathways, molecular biology methods for assembly of DNA parts into pathways, and for introducing the pathways into the host, and finally approaches for optimizing performance of the introduced pathways. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.

An evolutionary perspective on the immunomodulatory role of hydrogen sulphide.

Science.gov (United States)

Rivers-Auty, J

2015-11-01

Most preclinical studies on endogenous hydrogen sulphide signalling have given little consideration to the fact that the human body contains more bacterial cells than human cells, and that evolution provides the context for all biology. Whether hydrogen sulphide is pro or anti-inflammatory is heavily debated within the literature, yet researchers have not fully considered that invasive bacteria produce hydrogen sulphide, often at levels far above the endogenous levels of the host. Here I argue that if hydrogen sulphide is an endogenous signalling molecule with immunomodulatory functions, then it must have evolved in the presence of virulent bacteria which produce hydrogen sulphide. This context leads to two competing theories about the evolution of endogenous hydrogen sulphide signalling. The detectable emission theory proposes that bacteria produce hydrogen sulphide as part of normal metabolism and hosts which evolved to detect and respond to this hydrogen sulphide would gain a selective survival advantage. This predicts that the endogenous production of hydrogen sulphide is a mechanism which amplifies the bacterial hydrogen sulphide signal. The opposing protective agent theory predicts that bacterial hydrogen sulphide is an effective defence against the bactericidal mechanisms of the host's immune response. In this case, endogenous hydrogen sulphide production is either at inconsequential levels to alter the immune response, or is involved in the inflammation resolution process. Evidence suggests that the direct interactions of hydrogen sulphide with the bactericidal mechanisms of the innate immune system are most congruent with the protective agent theory. Therefore, I argue that if hydrogen sulphide is an immunomodulatory endogenous signalling molecule its effects are most likely anti-inflammatory. Copyright © 2015 Elsevier Ltd. All rights reserved.

Dynamics of urokinase receptor interaction with Peptide antagonists studied by amide hydrogen exchange and mass spectrometry

DEFF Research Database (Denmark)

Jørgensen, Thomas J D; Gårdsvoll, Henrik; Danø, Keld

2004-01-01

Using amide hydrogen exchange combined with electrospray ionization mass spectrometry, we have in this study determined the number of amide hydrogens on several peptides that become solvent-inaccessible as a result of their high-affinity interaction with the urokinase-type plasminogen activator...... receptor (uPAR). These experiments reveal that at least six out of eight amide hydrogens in a synthetic nine-mer peptide antagonist (AE105) become sequestered upon engagement in uPAR binding. Various uPAR mutants with decreased affinity for this peptide antagonist gave similar results, thereby indicating...... that deletion of the favorable interactions involving the side chains of these residues in uPAR does not affect the number of hydrogen bonds established by the main chain of the peptide ligand. The isolated growth factor-like domain (GFD) of the cognate serine protease ligand for uPAR showed 11 protected amide...

Synthetic fuel production via carbon neutral cycles with high temperature nuclear reactors as a power source

Energy Technology Data Exchange (ETDEWEB)

Konarek, E.; Coulas, B.; Sarvinis, J. [Hatch Ltd., Mississauga, Ontario (Canada)

2016-06-15

This paper analyzes a number of carbon neutral cycles, which could be used to produce synthetic hydrocarbon fuels. Synthetic hydrocarbons are produced via the synthesis of Carbon Monoxide and Hydrogen. The . cycles considered will either utilize Gasification processes, or carbon capture as a source of feed material. In addition the cycles will be coupled to a small modular Nuclear Reactor (SMR) as a power and heat source. The goal of this analysis is to reduce or eliminate the need to transport diesel and other fossil fuels to remote regions and to provide a carbon neutral, locally produced hydrocarbon fuel for remote communities. The technical advantages as well as the economic case are discussed for each of the cycles presented. (author)

Synthetic fuel production via carbon neutral cycles with high temperature nuclear reactors as a power source

International Nuclear Information System (INIS)

Konarek, E.; Coulas, B.; Sarvinis, J.

2016-01-01

This paper analyzes a number of carbon neutral cycles, which could be used to produce synthetic hydrocarbon fuels. Synthetic hydrocarbons are produced via the synthesis of Carbon Monoxide and Hydrogen. The . cycles considered will either utilize Gasification processes, or carbon capture as a source of feed material. In addition the cycles will be coupled to a small modular Nuclear Reactor (SMR) as a power and heat source. The goal of this analysis is to reduce or eliminate the need to transport diesel and other fossil fuels to remote regions and to provide a carbon neutral, locally produced hydrocarbon fuel for remote communities. The technical advantages as well as the economic case are discussed for each of the cycles presented. (author)

Quantitative proteomics suggests metabolic reprogramming during ETHE1 deficiency

DEFF Research Database (Denmark)

Sahebekhtiari, Navid; Thomsen, Michelle M.; Sloth, Jens Jørgen

2016-01-01

Deficiency of mitochondrial sulfur dioxygenase (ETHE1) causes the severe metabolic disorder ethylmalonic encephalopathy, which is characterized by early-onset encephalopathy and defective cytochrome C oxidase because of hydrogen sulfide accumulation. Although the severe systemic consequences of t...

Hydrogen system (hydrogen fuels feasibility)

International Nuclear Information System (INIS)

Guarna, S.

1991-07-01

This feasibility study on the production and use of hydrogen fuels for industry and domestic purposes includes the following aspects: physical and chemical properties of hydrogen; production methods steam reforming of natural gas, hydrolysis of water; liquid and gaseous hydrogen transportation and storage (hydrogen-hydride technology); environmental impacts, safety and economics of hydrogen fuel cells for power generation and hydrogen automotive fuels; relevant international research programs

Designing synthetic biology.

Science.gov (United States)

Agapakis, Christina M

2014-03-21

Synthetic biology is frequently defined as the application of engineering design principles to biology. Such principles are intended to streamline the practice of biological engineering, to shorten the time required to design, build, and test synthetic gene networks. This streamlining of iterative design cycles can facilitate the future construction of biological systems for a range of applications in the production of fuels, foods, materials, and medicines. The promise of these potential applications as well as the emphasis on design has prompted critical reflection on synthetic biology from design theorists and practicing designers from many fields, who can bring valuable perspectives to the discipline. While interdisciplinary connections between biologists and engineers have built synthetic biology via the science and the technology of biology, interdisciplinary collaboration with artists, designers, and social theorists can provide insight on the connections between technology and society. Such collaborations can open up new avenues and new principles for research and design, as well as shed new light on the challenging context-dependence-both biological and social-that face living technologies at many scales. This review is inspired by the session titled "Design and Synthetic Biology: Connecting People and Technology" at Synthetic Biology 6.0 and covers a range of literature on design practice in synthetic biology and beyond. Critical engagement with how design is used to shape the discipline opens up new possibilities for how we might design the future of synthetic biology.

Radioimmunoassay of synthetic steroids

Energy Technology Data Exchange (ETDEWEB)

Raynaud, J -P; Bucourt, R; Salmon, J

1975-12-01

The sensitivity of a radioimmunoassay depends on the intrinsic association constant of the interaction between ligand and antibody. Its specificity depends on the position of the chain which forms the link with the antigen. Thus, an antibody specific of estradiol has been obtained by coupling estradiol to albumin via a chain at position 7. For synthetic steroids the structure of which is sufficiency different from that of natural hormones, the requirements for a sensitive assay method not involving chromatography are simply maximum affinity and positioning of the couple at a site which does not undergo metabolic attack. These criteria were used to develop assays for R 2858 and R 2453 which obviate the need to administer radioactive product in clinical pharmacology. Cross-reaction with structural analogs may be used to assay competitors. Thus, R 2323 antibody, highly specific for endogenous steroids, may be used to assay other trienes such as R 1697 (trenbolone) and R 2010 (norgestrienone).

Workshop Papers: Directions and Marketing of Synthetic Crude Oil and Heavy Oil

International Nuclear Information System (INIS)

1997-01-01

This workshop was organized by the National Centre for Upgrading Technology in an effort to bring together experts from the various sectors of the petroleum industry to outline their views of the directions that the synthetic crude oil market will pursue over the next decade and into the 21. century. The motivation for the Workshop came from the many announcements during 1996 and 1997 by several Canadian oil companies about plans to initiate or expand their heavy oil and synthetic crude production. During the same period, at least one US refiner also announced plans to revamp an existing refinery to allow it to process Canadian heavy oil and synthetic crude. The workshop was organized to review these plans and to discuss such questions as (1) Would the selected technologies be the familiar carbon rejection or hydrogen addition methods, or would there be radical advanced technologies? (2) Would the products be fully or partially upgraded? (3) How would they be processed in the refinery? (4) Would there be a market? This collection of papers or viewgraphs comprise all the formal presentations given at the workshop. The final section also contains the edited notes recorded during the question and answer periods. refs., tabs., figs

Fiscal 1975 Sunshine Project research report. General research on hydrogen energy subsystems and their peripheral technologies (Research on hydrogen engine for aircraft); 1975 nendo suiso riyo subsystem no sogoteki kento to shuhen gijutsu ni kansuru kenkyu seika hokokusho. Kokukiyo suiso engine ni kansuru chosa

Energy Technology Data Exchange (ETDEWEB)

NONE

1976-05-01

This report summarizes the research results on (1) the prospect of an aviation system based on hydrogen energy, (2) the total system of aircraft based on hydrogen energy, and (3) the performance, structure and specifications of airplanes and engines using synthetic fuel such as hydrogen. In (1), study was made on air transport energy, and prediction was made on the demand of liquid hydrogen assuming conversion of petroleum fuel into hydrogen fuel in the future. In (2), the supply system of liquid hydrogen is essential in conversion of current aircraft fuel into liquid hydrogen. Such supply system over the world is also necessary in conversion into liquid hydrogen for both domestic and international airlines. In (3), in order to discuss the feasibility of liquid hydrogen fuel aircraft, the merit of such aircraft as compared with current aircraft using JP fuel, and whether designing a new airframe or modifying existing airframes, study was made conceptually on the size and capacity of airframe by statistical treatment and analysis of previous conceptual designs. (NEDO)

Metabolism of a new synthetic progestagen, Org 2969, in female volunteers. The distribution and excretion of radioactivity after an oral dose of the labelled drug

Energy Technology Data Exchange (ETDEWEB)

Viinikka, L; Ylikorkala, O; Vihko, R [Oulu Univ. (Finland); Hasenack, H G; Nieuwenhuyse, H [Organon Scientific Development Group, Organon Int., Oss, The Netherlands

1980-01-01

The metabolism of a new synthetic progestagen, Org 2969 was studied in 4 healthy female volunteers. During the first part of the study (Phase I), the volunteers ingested 50 ..mu..g (about 0.1 mCi) of (16-/sup 3/H)Org 2969 together with 50 ..mu..g of ethinyloestradiol as a single dose. During the second part of the study (Phase II), a 10-day pre-treatment with the same dosage of non-radioactive compound preceded the administration of the radioactive steroid. A peak level of total radioactivity, representing 3.16-5.02% of the dose given/l of serum, was achieved within 2-3 h in Phase I. During Phase II, the corresponding figures were 4.54-5.13% after 1.5-3 h. The difference was mainly due to an increase of freely-extractable steroids during Phase II. The difference can at least partly be explained by assuming a change in the kinetics of the metabolism of Org 2969 by pre-treatment with Org 2969 and ethinyloestradiol. The mean recovery of radioactivity in urine and faeces was 83.0%/48.1%/34.9% (total/urine/faeces) of the total dose in Phase I and 76.1%/45.2%/30.9% during Phase II. The differences in the total excretion and in the radioactivity excreted in the faeces were significant.

First Characterization of AKB-48 Metabolism, a Novel Synthetic Cannabinoid, Using Human Hepatocytes and High-Resolution Mass Spectrometry

OpenAIRE

Gandhi, Adarsh S.; Zhu, Mingshe; Pang, Shaokun; Wohlfarth, Ariane; Scheidweiler, Karl B.; Liu, Hua-fen; Huestis, Marilyn A.

2013-01-01

Since the federal authorities scheduled the first synthetic cannabinoids, JWH-018 and JWH-073, new synthetic cannabinoids were robustly marketed. N-(1-Adamantyl)-1-pentylindazole-3-carboxamide (AKB-48), also known as APINACA, was recently observed in Japanese herbal smoking blends. The National Forensic Laboratory Information System registered 443 reports of AKB-48 cases in the USA from March 2010 to January 2013. In May 2013, the Drug Enforcement Administration listed AKB-48 as a Schedule I ...

Using hydrogen isotopes to assign origins of bats in the eastern United States

Science.gov (United States)

Eric R. Britzke; Susan C. Loeb; Keith A. Hobson; Christopher S. Romanek; Maarten J. Vonhof

2009-01-01

Stable hydrogen isotopes (dDs) in metabolically inert tissues such as feathers and hair provide a set of endogenous markers that may be useful for establishing migratory connectivity in animals. We tested the assumption...

Development of a formaldehyde biosensor with application to synthetic methylotrophy.

Science.gov (United States)

Woolston, Benjamin M; Roth, Timothy; Kohale, Ishwar; Liu, David R; Stephanopoulos, Gregory

2018-01-01

Formaldehyde is a prevalent environmental toxin and a key intermediate in single carbon metabolism. The ability to monitor formaldehyde concentration is, therefore, of interest for both environmental monitoring and for metabolic engineering of native and synthetic methylotrophs, but current methods suffer from low sensitivity, complex workflows, or require expensive analytical equipment. Here we develop a formaldehyde biosensor based on the FrmR repressor protein and cognate promoter of Escherichia coli. Optimization of the native repressor binding site and regulatory architecture enabled detection at levels as low as 1 µM. We then used the sensor to benchmark the in vivo activity of several NAD-dependent methanol dehydrogenase (Mdh) variants, the rate-limiting enzyme that catalyzes the first step of methanol assimilation. In order to use this biosensor to distinguish individuals in a mixed population of Mdh variants, we developed a strategy to prevent cross-talk by using glutathione as a formaldehyde sink to minimize intercellular formaldehyde diffusion. Finally, we applied this biosensor to balance expression of mdh and the formaldehyde assimilation enzymes hps and phi in an engineered E. coli strain to minimize formaldehyde build-up while also reducing the burden of heterologous expression. This biosensor offers a quick and simple method for sensitively detecting formaldehyde, and has the potential to be used as the basis for directed evolution of Mdh and dynamic formaldehyde control strategies for establishing synthetic methylotrophy. © 2017 Wiley Periodicals, Inc.

One-pot reduction of 5-hydroxymethylfurfural via hydrogen transfer from supercritical methanol

DEFF Research Database (Denmark)

Hansen, Thomas Søndergaard; Barta, Katalin; Anastas, Paul T.

2012-01-01

Catalytic conversion of HMF to valuable chemicals was achieved over a Cu-doped porous metal oxide in supercritical methanol. The hydrotalcite catalyst precursor is prepared following simple synthetic procedures, using inexpensive and earth-abundant starting materials in aqueous solutions. The hyd......Catalytic conversion of HMF to valuable chemicals was achieved over a Cu-doped porous metal oxide in supercritical methanol. The hydrotalcite catalyst precursor is prepared following simple synthetic procedures, using inexpensive and earth-abundant starting materials in aqueous solutions....... The hydrogen equivalents needed for the reductive deoxygenation of HMF originate from the solvent itself upon its reforming. Dimethylfuran, dimethyltetrahydrofuran and 2-hexanol were obtained in good yields. At milder reaction temperatures, a combined yield (DMF + DMTHF) of 58% was achieved. Notably...

CO metabolism of carboxydothermus hydrogenoformans and archaeoglobus fulgidus

NARCIS (Netherlands)

Henstra, A.M.

2006-01-01

Microbial CO metabolism was studied in detail with the ultimate aim to assess the feasibility of a biotechnological process that could replace the existing water gas shift technology in the production of a fuel cell grade hydrogen gas from synthesis gas. It is expected that a biotechnological

Plant synthetic biology for molecular engineering of signalling and development.

Science.gov (United States)

Nemhauser, Jennifer L; Torii, Keiko U

2016-03-02

Molecular genetic studies of model plants in the past few decades have identified many key genes and pathways controlling development, metabolism and environmental responses. Recent technological and informatics advances have led to unprecedented volumes of data that may uncover underlying principles of plants as biological systems. The newly emerged discipline of synthetic biology and related molecular engineering approaches is built on this strong foundation. Today, plant regulatory pathways can be reconstituted in heterologous organisms to identify and manipulate parameters influencing signalling outputs. Moreover, regulatory circuits that include receptors, ligands, signal transduction components, epigenetic machinery and molecular motors can be engineered and introduced into plants to create novel traits in a predictive manner. Here, we provide a brief history of plant synthetic biology and significant recent examples of this approach, focusing on how knowledge generated by the reference plant Arabidopsis thaliana has contributed to the rapid rise of this new discipline, and discuss potential future directions.

Hydrogen Storage in Metal-Organic Frameworks

Energy Technology Data Exchange (ETDEWEB)

Long, Jeffrey R. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2016-04-28

rigorous understanding of experimental findings was further achieved via first-principles electronic structure calculations, which also supported synthetic efforts through predictions of additional novel frameworks with promising properties for vehicular H₂ storage. The results of the computational efforts also helped to elucidate the fundamental principles governing the interaction of H₂ with the frameworks, and in particular with exposed metal sites in the pores of these materials. Significant accomplishments from this project include the discovery of a metal-organic framework with a high H₂ binding enthalpy and volumetric capacity at 25 °C and 100 bar, which surpasses the metrics of any other known metal-organic framework. Additionally this material was designed to be extremely cost effective compared to most comparable adsorbents, which is imperative for eventual real-world applications. Progress toward synthesizing new frameworks containing multiple open coordination sites is also discussed, and appears to be the most promising future direction for hydrogen storage in these porous materials.

Synthetic biology for engineering acetyl coenzyme a metabolism in yeast

DEFF Research Database (Denmark)

Nielsen, Jens

2014-01-01

The yeast Saccharomyces cerevisiae is a widely used cell factory for the production of fuels, chemicals, and pharmaceuticals. The use of this cell factory for cost-efficient production of novel fuels and chemicals requires high yields and low by-product production. Many industrially interesting...... chemicals are biosynthesized from acetyl coenzyme A (acetyl-CoA), which serves as a central precursor metabolite in yeast. To ensure high yields in production of these chemicals, it is necessary to engineer the central carbon metabolism so that ethanol production is minimized (or eliminated) and acetyl...

Biohydrogen production from xylose at extreme thermophilic temperatures (70 degrees C) by mixed culture fermentation

DEFF Research Database (Denmark)

Kongjan, Prawit; Min, Booki; Angelidaki, Irini

2009-01-01

/L. Addition of yeast extract in the cultivation medium resulted in significant improvement of hydrogen yield. The main metabolic products during xylose fermentation were acetate, ethanol, and lactate. The specific growth rates were able to fit the experimental points relatively well with Haldane equation...... solid wastes at 70 degrees C. The highest hydrogen yield of 1.62 +/- 0.02 mol-H-2/Mol-xylose(consumed) was obtained at initial xylose concentration of 0.5 g/L with synthetic medium amended with I g/L of yeast extract. Lower hydrogen yield was achieved at initial xylose concentration higher than 2 g...

Regulation of hydrogen production by Enterobacter aerogenes by external NADH and NAD{sup +}

Energy Technology Data Exchange (ETDEWEB)

Zhang, Chong; Ma, Kun; Xing, Xin-Hui [Department of Chemical Engineering, Tsinghua University, Beijing 100084 (China)

2009-02-15

Experiments involving the addition of external nicotinamide adenine dinucleotide, reduced form (NADH) or nicotinamide adenine dinucleotide (NAD{sup +}) have been designed to examine how the hydrogen in Enterobacter aerogenes is liberated by NADH or NAD{sup +}. The addition of external NADH or NAD{sup +} was found to regulate hydrogen production by E. aerogenes in resting cells, batch cultures, and chemostat cultures. Particularly in chemostat cultivation, with the external addition of NADH, hydrogen production via the NADH pathway was decreased, while that via the formate pathway was increased; in the end, the overall hydrogen p was decreased. The addition of NAD{sup +}, on the other hand, gave the opposite results. The membrane-bound hydrogenase was found to play a central role in regulating hydrogen production. The occurrence of NADH oxidation (NAD{sup +} reduction) on the cell membrane resulted in an electron flow across the membrane; this changed the oxidation state and metabolic pattern of the cells, which eventually affected the hydrogen evolution. (author)

Manganese-Oxygen Intermediates in O-O Bond Activation and Hydrogen-Atom Transfer Reactions.

Science.gov (United States)

Rice, Derek B; Massie, Allyssa A; Jackson, Timothy A

2017-11-21

Biological systems capitalize on the redox versatility of manganese to perform reactions involving dioxygen and its derivatives superoxide, hydrogen peroxide, and water. The reactions of manganese enzymes influence both human health and the global energy cycle. Important examples include the detoxification of reactive oxygen species by manganese superoxide dismutase, biosynthesis by manganese ribonucleotide reductase and manganese lipoxygenase, and water splitting by the oxygen-evolving complex of photosystem II. Although these enzymes perform very different reactions and employ structurally distinct active sites, manganese intermediates with peroxo, hydroxo, and oxo ligation are commonly proposed in catalytic mechanisms. These intermediates are also postulated in mechanisms of synthetic manganese oxidation catalysts, which are of interest due to the earth abundance of manganese. In this Account, we describe our recent efforts toward understanding O-O bond activation pathways of Mn III -peroxo adducts and hydrogen-atom transfer reactivity of Mn IV -oxo and Mn III -hydroxo complexes. In biological and synthetic catalysts, peroxomanganese intermediates are commonly proposed to decay by either Mn-O or O-O cleavage pathways, although it is often unclear how the local coordination environment influences the decay mechanism. To address this matter, we generated a variety of Mn III -peroxo adducts with varied ligand environments. Using parallel-mode EPR and Mn K-edge X-ray absorption techniques, the decay pathway of one Mn III -peroxo complex bearing a bulky macrocylic ligand was investigated. Unlike many Mn III -peroxo model complexes that decay to oxo-bridged-Mn III Mn IV dimers, decay of this Mn III -peroxo adduct yielded mononuclear Mn III -hydroxo and Mn IV -oxo products, potentially resulting from O-O bond activation of the Mn III -peroxo unit. These results highlight the role of ligand sterics in promoting the formation of mononuclear products and mark an important

Synthetic biology and regulatory networks: where metabolic systems biology meets control engineering

NARCIS (Netherlands)

He, F.; Murabito, E.; Westerhoff, H.V.

2016-01-01

Metabolic pathways can be engineered to maximize the synthesis of various products of interest. With the advent of computational systems biology, this endeavour is usually carried out throughin silicotheoretical studies with the aim to guide and complement furtherin vitroandin vivoexperimental

Thermophilic fermentative hydrogen production from starch-wastewater with bio-granules

Energy Technology Data Exchange (ETDEWEB)

Akutsu, Yohei; Harada, Hideki [Department of Civil and Environmental Engineering, Tohoku University, 6-6-06 Aoba, Sendai, Miyagi 980-8579 (Japan); Lee, Dong-Yeol [Research Center for Material Cycles and Waste Management, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506 (Japan); Chi, Yong-Zhi [Department of Environmental and Municipal Engineering, Tianjin Institute of Urban Construction, Jinjinggonglu 26, Tianjin 300384 (China); Li, Yu-You [Department of Environmental and Municipal Engineering, Tianjin Institute of Urban Construction, Jinjinggonglu 26, Tianjin 300384 (China); Department of Environmental Science, Tohoku University, 6-6-06 Aoba, Sendai, Miyagi 980-8579 (Japan); Yu, Han-Qing [School of Chemistry, University of Science and Technology of China, Hefei 230026 (China)

2009-06-15

In this study, the effects of the hydraulic retention time (HRT), pH and substrate concentration on the thermophilic hydrogen production of starch with an upflow anaerobic sludge bed (UASB) reactor were investigated. Starch was used as a sole substrate. Continuous hydrogen production was stably attained with a maximum H{sub 2} yield of 1.7 mol H{sub 2}/mol glucose. A H{sub 2}-producing thermophilic granule was successfully formed with diameter in the range of 0.5-4.0 mm with thermally pretreated methanogenic granules as the nuclei. The metabolic pathway of the granules was drastically changed at each operational parameter. The production of formic or lactic acids is an indication of the deterioration of hydrogen production for H{sub 2}-producing thermophilic granular sludge. (author)

Glycerophosphate-dependent hydrogen peroxide production by rat liver mitochondria

Czech Academy of Sciences Publication Activity Database

Ješina, Pavel; Kholová, D.; Bolehovská, R.; Červinková, Z.; Drahota, Zdeněk; Houštěk, Josef

2004-01-01

Roč. 53, č. 3 (2004), s. 305-310 ISSN 0862-8408 R&D Projects: GA ČR GA303/03/0799; GA MŠk OC 918.50 Institutional research plan: CEZ:AV0Z5011922 Keywords : mitochondrial glycerophosphate dehydrogenace * triiodothyronine * hydrogen peroxide Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition Impact factor: 1.140, year: 2004

Hydrogen utilization potential in subsurface sediments

Directory of Open Access Journals (Sweden)

Rishi Ram Adhikari

2016-01-01

Full Text Available Subsurface microbial communities undertake many terminal electron-accepting processes, often simultaneously. Using a tritium-based assay, we measured the potential hydrogen oxidation catalyzed by hydrogenase enzymes in several subsurface sedimentary environments (Lake Van, Barents Sea, Equatorial Pacific and Gulf of Mexico with different predominant electron-acceptors. Hydrogenases constitute a diverse family of enzymes expressed by microorganisms that utilize molecular hydrogen as a metabolic substrate, product or intermediate. The assay reveals the potential for utilizing molecular hydrogen and allows qualitative detection of microbial activity irrespective of the predominant electron-accepting process. Because the method only requires samples frozen immediately after recovery, the assay can be used for identifying microbial activity in subsurface ecosystems without the need to preserve live material.We measured potential hydrogen oxidation rates in all samples from multiple depths at several sites that collectively span a wide range of environmental conditions and biogeochemical zones. Potential activity normalized to total cell abundance ranges over five orders of magnitude and varies, dependent upon the predominant terminal electron acceptor. Lowest per-cell potential rates characterize the zone of nitrate reduction and highest per-cell potential rates occur in the methanogenic zone. Possible reasons for this relationship to predominant electron acceptor include (i increasing importance of fermentation in successively deeper biogeochemical zones and (ii adaptation of H2ases to successively higher concentrations of H2 in successively deeper zones.

Well-to-wheel analysis of renewable transport fuels: synthetic natural gas from wood gasification and hydrogen from concentrated solar energy[Dissertation 17437

Energy Technology Data Exchange (ETDEWEB)

Felder, R.

2007-07-01

In order to deal with problems such as climate change, an increasing energy demand and the finiteness of fossil resources, alternative CO{sub 2}-low technologies have to be found for a sustainable growing future. Laboratories at PSI are conducting research on two pathways delivering such car fuels: synthetic natural gas from wood gasification (SNG) and hydrogen from solar thermochemical ZnO dissociation (STD). The biofuel SNG is produced using wood in an auto-thermal gasification reactor. It can be supplied to the natural-gas grid and be used in a compressed natural gas (CNG) vehicle. STD is a long-term option, using concentrated solar radiation in a thermochemical reactor, producing zinc as solar energy carrier. Zinc can be used for hydrolysis, in order to produce hydrogen as a locally low-polluting future car fuel. In the frame of the thesis, both fuels are assessed using a life cycle assessment, i.e. investigating all environmental interactions from the extraction of resources over the processing and usage steps to the final disposal. Different methodologies are applied for a rating, compared to alternatives and standard fuels of today. In addition, costs of the technologies are calculated in order to assess economic competitiveness. The thesis is structured as follows: After an introduction giving an overview (chapter A), the methodology is presented (chapter B). It includes various life cycle impact assessment methods such as greenhouse gas emissions, the cumulative energy demand or comprehensive rating approaches. Calculations of the production and supply costs of the assessed fuels are included as well as the eco-efficiency, a combination of environmental with economic indicators. In addition, external costs caused by the emissions are quantified. Sensitivity studies investigate the importance of different parameters and substantiate conclusions. In chapter C, the production, supply and use of the assessed fuels is discussed, following the well

Melatonin as a Potent and Inducible Endogenous Antioxidant: Synthesis and Metabolism

Directory of Open Access Journals (Sweden)

Dun-Xian Tan

2015-10-01

Full Text Available Melatonin is a tryptophan-derived molecule with pleiotropic activities. It is present in almost all or all organisms. Its synthetic pathway depends on the species in which it is measured. For example, the tryptophan to melatonin pathway differs in plants and animals. It is speculated that the melatonin synthetic machinery in eukaryotes was inherited from bacteria as a result of endosymbiosis. However, melatonin’s synthetic mechanisms in microorganisms are currently unknown. Melatonin metabolism is highly complex with these enzymatic processes having evolved from cytochrome C. In addition to its enzymatic degradation, melatonin is metabolized via pseudoenzymatic and free radical interactive processes. The metabolic products of these processes overlap and it is often difficult to determine which process is dominant. However, under oxidative stress, the free radical interactive pathway may be featured over the others. Because of the complexity of the melatonin degradative processes, it is expected that additional novel melatonin metabolites will be identified in future investigations. The original and primary function of melatonin in early life forms such as in unicellular organisms was as a free radical scavenger and antioxidant. During evolution, melatonin was selected as a signaling molecule to transduce the environmental photoperiodic information into an endocrine message in multicellular organisms and for other purposes as well. As an antioxidant, melatonin exhibits several unique features which differ from the classic antioxidants. These include its cascade reaction with free radicals and its capacity to be induced under moderate oxidative stress. These features make melatonin a potent endogenously-occurring antioxidant that protects organisms from catastrophic oxidative stress.

The storage of hydrogen and the problems it involves

International Nuclear Information System (INIS)

Schmitt, R.; Jonville, P.

1975-01-01

The limitation of fossil fuel resources has brought about active research in the field of synthetic fuels which, in the more or less near future, could lead to freedom from dependence on production of the former. On a long-term basis, hydrogen would appear to be the best candidate as a substitute for conventional fuels. Among the possibilities of storage in a motor vehicle, its absorption in a metallic hydride provides the most attractive solution. Account taken of the weight limitations of this storage method, the use of hydrogen in an internal combustion engine can be envisaged only for short-range urban vehicles. Optimal use of its energy content will be made possible by means of fuel cells. The development of such a storage-propulsion chain nevertheless requires considerable work in research and development, both for the study of hydrides and the technology of fuel cells [fr

Freedom and Responsibility in Synthetic Genomics: The Synthetic Yeast Project

OpenAIRE

Sliva, Anna; Yang, Huanming; Boeke, Jef D.; Mathews, Debra J. H.

2015-01-01

First introduced in 2011, the Synthetic Yeast Genome (Sc2.0) Project is a large international synthetic genomics project that will culminate in the first eukaryotic cell (Saccharomyces cerevisiae) with a fully synthetic genome. With collaborators from across the globe and from a range of institutions spanning from do-it-yourself biology (DIYbio) to commercial enterprises, it is important that all scientists working on this project are cognizant of the ethical and policy issues associated with...

Space Synthetic Biology Project

Science.gov (United States)

Howard, David; Roman, Monsi; Mansell, James (Matt)

2015-01-01

Synthetic biology is an effort to make genetic engineering more useful by standardizing sections of genetic code. By standardizing genetic components, biological engineering will become much more similar to traditional fields of engineering, in which well-defined components and subsystems are readily available in markets. Specifications of the behavior of those components and subsystems can be used to model a system which incorporates them. Then, the behavior of the novel system can be simulated and optimized. Finally, the components and subsystems can be purchased and assembled to create the optimized system, which most often will exhibit behavior similar to that indicated by the model. The Space Synthetic Biology project began in 2012 as a multi-Center effort. The purpose of this project was to harness Synthetic Biology principals to enable NASA's missions. A central target for application was to Environmental Control & Life Support (ECLS). Engineers from NASA Marshall Space Flight Center's (MSFC's) ECLS Systems Development Branch (ES62) were brought into the project to contribute expertise in operational ECLS systems. Project lead scientists chose to pursue the development of bioelectrochemical technologies to spacecraft life support. Therefore, the ECLS element of the project became essentially an effort to develop a bioelectrochemical ECLS subsystem. Bioelectrochemical systems exploit the ability of many microorganisms to drive their metabolisms by direct or indirect utilization of electrical potential gradients. Whereas many microorganisms are capable of deriving the energy required for the processes of interest (such as carbon dioxide (CO2) fixation) from sunlight, it is believed that subsystems utilizing electrotrophs will exhibit smaller mass, volume, and power requirements than those that derive their energy from sunlight. In the first 2 years of the project, MSFC personnel conducted modeling, simulation, and conceptual design efforts to assist the

Investigation of hydrogenase molecular marker to optimize hydrogen production from organic wastes and effluents of agro-food industries [abstract

Directory of Open Access Journals (Sweden)

Hamilton, C.

2010-01-01

Full Text Available In recent years policy makers have started looking for alternatives to fossil fuels, not only to counter the threat of global warming, but also to reduce the risk of overdependence on imported oil and gas supplies. By contrast with hydrocarbon fuels, hydrogen (H2, whether burned directly or used in fuel cells, is intrinsically a clean energy vector with near zero emission. However the main current method of producing hydrogen, steam reforming of methane, involves the release of large quantities of greenhouse gases. So although hydrogen already accounts for around 2% of world consumption of energy, its more widespread adoption is limited by several challenges. Therefore new processes are investigated, especially those using renewable raw material, e.g. woods and organic wastes, and/or involving microorganisms. Indeed, for some algae and bacteria, the generation of molecular hydrogen is an essential part of their energy metabolism. The approach with the greatest commercial potential is fermentative hydrogen generation (dark fermentation by bacteria from the Clostridium genus. This biological process, as a part of the methane-producing anaerobic digestion process, is very promising since it allows the production of hydrogen from a wide variety of renewable resources such as carbohydrate waste from the agricultural and agro-food industries or processed urban waste and sewage. To date most publications on hydrogen production by Clostridium strains have focused on the effects of operating parameters (such as temperature, pH, dilution rate, etc.. We now need to extend this knowledge by identifying and monitoring the various different metabolic agents involved in high H2 activity. Consequently the aim of this research at the CWBI in the University of Liege is to investigate the role of [Fe] hydrogenases, the key enzymes that remove excess electrons accumulating during fermentation. Clostridium butyricum CWBI1009, the strain used for these investigations

Synthetic genome engineering forging new frontiers for wine yeast.

Science.gov (United States)

Pretorius, Isak S

2017-02-01

holds is the de novo production of the raspberry ketone aroma compound, 4-[4-hydroxyphenyl]butan-2-one, in a wine yeast strain (AWRI1631), which was recently achieved via metabolic pathway engineering and synthetic enzyme fusion. A peek over the horizon is revealing that the future of "Wine Yeast 2.0" is already here. Therefore, this article seeks to help prepare the wine industry - an industry rich in history and tradition on the one hand, and innovation on the other - for the inevitable intersection of the ancient art practiced by winemakers and the inventive science of pioneering "synthetic genomicists". It would be prudent to proactively engage all stakeholders - researchers, industry practitioners, policymakers, regulators, commentators, and consumers - in a meaningful dialog about the potential challenges and opportunities emanating from Synthetic Biology. To capitalize on the new vistas of synthetic yeast genomics, this paper presents wine yeast research in a fresh context, raises important questions and proposes new directions.

Extremophile mediated hydrogen production for hydrogenation of substrates in aqueous media

Science.gov (United States)

Anjom, Mouzhgun

Catalytic hydrogenation reactions are pervasive throughout our economy, from production of margarine as food, liquid fuels for transportation and chiral drugs such as L-DOPA. H2 production from non-fossil fuel feedstocks is highly desirable for transition to the "Hydrogen Economy". Also, the rates of hydrogenation reactions that involve a substrate, H 2 gas and a catalyst are often limited by the solubility of H2 in solvent. The present research thus envisioned designing water-soluble catalysts that could effectively utilize biologically produced H2 in a coupled system to hydrogenate substrates in homogeneous mode (two-phase system). Biological production of H2 as an end product or byproduct of the metabolism of organisms that operate under strict anaerobic conditions has been proposed. However, contrary to what was previously observed, Thermotoga neapolitana, belonging to the order of Thermotogales efficiently produces H2 gas under microaerobic conditions (Van Ooteghem et al. 2004). For H2 production by T. neapolitana in the bacterial growth medium (DSM 5068) at an optimum temperature of 70 C, our results in batch mode show that: (1) H2 was produced from glucose though with 16% efficiency, the rest goes to biomass production, (2) H2 gas was produced even when the cultures were inoculated under microaerobic conditions (up to 8% (v/v) O2) suggesting a protective mechanism for one or more [Fe-Fe] hydrogenases in T. neapolitana, (3) H2 production was pH dependent but addition of simple, non-toxic physiological buffering additives such as Methylene succinic acid increased H2 production and (4) H2 production rate varied linearly in the 100--6800 kPa pressure range. We then screened various water-soluble metal catalysts in batch mode and selected the RhCl3.3H2O/TPPTS (TPPTS is a water-soluble ligand) system that achieved 86% hydrogenation of Methylene succinic acid (an olefin) in an aqueous medium pressurized with preformed H2. When water was replaced with the DSM 5068

Assessment of the potential future market in Sweden for hydrogen as an energy carrier

Science.gov (United States)

Carleson, G.

Future hydrogen markets for the period 1980-2025 are projected, the probable range of hydrogen production costs for various manufacturing methods is estimated, and expected market shares in competition with alternative energy carriers are evaluated. A general scenario for economic and industrial development in Sweden for the given period was evaluated, showing the average increase in gross national product to become 1.6% per year. Three different energy scenarios were then developed: alternatives were based on nuclear energy, renewable indigenous energy sources, and the present energy situation with free access to imported natural or synthetic fuels. An analysis was made within each scenario of the competitiveness of hydrogen on both the demand and the supply of the following sectors: chemical industry, steel industry, peak power production, residential and commercial heating, and transportation. Costs were calculated for the production, storage and transmission of hydrogen according to technically feasible methods and were compared to those of alternative energy carriers. Health, environmental and societal implications were also considered. The market penetration of hydrogen in each sector was estimated, and the required investment capital was shown to be less than 4% of the national gross investment sum.

Characterization of Thermal Stability of Synthetic and Semi-Synthetic Engine Oils

Directory of Open Access Journals (Sweden)

Anand Kumar Tripathi

2015-03-01

Full Text Available Engine oils undergo oxidative degradation and wears out during service. Hence it is important to characterize ageing of engine oils at different simulated conditions to evaluate the performance of existing oils and also design new formulations. This work focuses on characterizing the thermo-oxidative degradation of synthetic and semi-synthetic engine oils aged at 120, 149 and 200 °C. Apparent activation energy of decomposition of aged oils evaluated using the isoconversional Kissinger-Akahira-Sunose technique was used as a thermal stability marker. The temporal variation of stability at different ageing temperatures was corroborated with kinematic viscosity, oxidation, sulfation and nitration indices, total base number, antiwear additive content and molecular structure of the organic species present in the oils. At the lowest temperature employed, synthetic oil underwent higher rate of oxidation, while semi-synthetic oil was stable for longer time periods. At higher temperatures, the initial rate of change of average apparent activation energy of synthetic oil correlated well with a similar variation in oxidation number. A mixture of long chain linear, branched, and cyclic hydrocarbons were observed when semi-synthetic oil was degraded at higher temperatures.

Molecular hydrogen: an energy source for bacterial activity in nuclear waste disposal

International Nuclear Information System (INIS)

Libert, M.; Esnault, L.

2010-01-01

Document available in extended abstract form only. Hydrogen is a common product of microbial metabolism, large number of bacteria are able to use it as energetic substrate in subsurface ecosystems. Moreover H 2 is known as one of the most energetic substrates for deep subsurface ecosystem. It could be produced in different ways mainly volcanic activity (basalts iron rich volcanic rocks) or natural radiolysis of water or even fermentation. The millimolar concentrations of H 2 observed in the ground waters are consistent with the activity of a large variety of hydrogen-oxidising bacteria as described in the following Table. Electron acceptors are identified as O 2 , CO 2 , NO 3 , SO 4 or Fe +++ . Aerobic, anaerobic, obligate and facultative autotrophs are included. Numerous of these bacteria are thermophilic bacteria. This bacterial activity leads to the production of methane, acetate, nitrogen, hydrogen sulphur or ferrous oxides. In anoxic environments, H 2 concentrations are governed by microbial metabolism. In most cases, H 2 producing microorganisms are thermodynamically controlled by the abundance of H 2 , and survive thanks to H 2 consumers, a metabolism called inter-species H 2 transfer. Metabolism of H 2 is catalysed by hydrogenase as cytoplasmic enzymes or membrane bound enzymes. Several situations of H 2 production will occur in nuclear waste repository: - Radiolysis of water. - Radiolysis of organic matter (such as bitumen, in case of B waste), H 2 production due to gamma radiolysis of bitumen is evaluated to 1 L H 2 /kg of bitumen /MGy. - Corrosion of metal containers (in deaerated solutions). Large amount of H 2 are predicted in some situations, and will select the development of hydrogen species. Then, aerobic hydrogen bacteria oxidising hydrogen could be found in basins containing irradiating waste, or during the oxic period of storage, denitrifying bacteria or sulfate reducing bacteria will develop near the bitumen waste. Groundwater of the Callovo

Development of new synthetic routes to bile pigments and synthesis of deuterated porphyrins

International Nuclear Information System (INIS)

Shim, Y.K.

1985-01-01

New synthetic routes to pyrromethanones using hydrogen peroxide/pyridine upon alpha-free pyrromethanes and a synthesis of mesobiliverdin are described. The pyrromethanones were applied to the synthesis of mesobiliverdin using 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) oxidation of mesourbilin, to give a high yield of the desired mesobiliverdin. New synthetic methodology to pyrrolinones using various oxidizing reagents were also described. Treatment of alpha-free pyrrole with thallium(III) trifluoroacetate (TTFA) gave a mixture of a pyrrolinone and a dimeric compound. The yield and the ratio of the two products were variable depending upon the solvents and the mole ratio of the TTFA used. Pyrrolinone syntheses using the other oxidizing reagents are also described. Syntheses of carbon-14 labelled biliverdins are also described. In addition, the preparation of biliverdin IX-BETA using b-bilene route is described. The second part of this study contains an introduction to porphyrins and syntheses of 6,7-bis(2-methoxycarbonyl-1,1-dideuteroethyl)-1,3,5,8-tetramethyl-2,4-divinylporphyrin. The latter is important in the study of heme protein reconstitution experiments. As a result of numerous synthetic approaches the desired product was obtained from the appropriately deuterated formylpyrrole using the a,c-biladiene route

The hydrogen; L'hydrogene

Energy Technology Data Exchange (ETDEWEB)

NONE

2004-07-01

The hydrogen as an energy system represents nowadays a main challenge (in a scientific, economical and environmental point of view). The physical and chemical characteristics of hydrogen are at first given. Then, the challenges of an hydrogen economy are explained. The different possibilities of hydrogen production are described as well as the distribution systems and the different possibilities of hydrogen storage. Several fuel cells are at last presented: PEMFC, DMFC and SOFC. (O.M.)

Specific SIRT1 activation mimics low energy levels and protects against diet-induced metabolic disorders by enhancing fat oxidation

NARCIS (Netherlands)

Feige, Jérôme N.; Lagouge, Marie; Canto, Carles; Strehle, Axelle; Houten, Sander M.; Milne, Jill C.; Lambert, Philip D.; Mataki, Chikage; Elliott, Peter J.; Auwerx, Johan

2008-01-01

The NAD(+)-dependent deacetylase SIRT1 controls metabolic processes in response to low nutrient availability. We report the metabolic phenotype of mice treated with SRT1720, a specific and potent synthetic activator of SIRT1 that is devoid of direct action on AMPK. SRT1720 administration robustly

Synthetic matrix of polyether-polyurethane as a biological platform for pancreatic regeneration.

Science.gov (United States)

Pereira, Luciana Xavier; Viana, Celso Tarso Rodrigues; Orellano, Laura Alejandra Ariza; Almeida, Simone Aparecida; Vasconcelos, Anilton Cesar; Goes, Alfredo de Miranda; Birbrair, Alexander; Andrade, Silvia Passos; Campos, Paula Peixoto

2017-05-01

Several alternative cellular approaches using biomaterials to host insulin-producing cells derived from stem cells have been developed to overcome the limitations of type 1 diabetes treatment (exogenous insulin injection). However, none seem to fulfill all requirements needed to induce pancreatic cells successful colonization of the scaffolds. Here, we report a polymeric platform adherent to the native mice pancreas filled with human adipose stem cells (hASCs) that was able to induce growth of pancreatic parenchyma. Synthetic polyether-polyurethane discs were placed adjacent to pancreas of normoglycemic and streptozotocin-induced diabetic mice. At day 4 post implantation, 1×10 6 hASCs were injected intra-implant in groups of normoglycemic and diabetic mice. Immunohistochemistry analysis of the implants was performed to identify insulin positive cells in the newly formed tissue. In addition, metabolic, inflammatory and angiogenic parameters were carried out in those mice. This study provides evidence of the ability of a biohybrid device to induce the growth of differentiated pancreas parenchyma in both normoglycemic and streptozotocin-induced diabetic mice as detected by histological analysis. Glucose metabolism and body weight of hyperglycemic mice bearing hASCs implants improved. The synthetic porous scaffold bearing hASC cells placed adjacent to the native animal pancreas exhibits the potential to be exploited in future cell-based type 1 diabetes therapies. Copyright © 2017 Elsevier Inc. All rights reserved.

Compressor-less Hydrogen Transmission Pipelines Deliver Large-scale Stranded Renewable Energy at Competitive Cost

International Nuclear Information System (INIS)

W Leighty; J Holloway; R Merer; B Somerday; C San Marchi; G Keith; D White

2006-01-01

We assume a transmission-constrained world, where large new wind plants and other renewable energies must pay all transmission costs for delivering their energy to distant markets. We modeled a 1,000 MW (1 GW) (name plate) wind plant in the large wind resource of the North America Great Plains, delivering exclusively hydrogen fuel, via a new gaseous hydrogen (GH2) pipeline, to an urban market at least 300 km distant. All renewable electric energy output would be converted, at the source, to hydrogen, via 100 bar output electrolyzers, directly feeding the GH2 transmission pipeline without costly compressor stations at inlet or at midline. The new GH2 pipeline is an alternative to new electric transmission lines. We investigate whether the pipeline would provide valuable energy storage. We present a simple model by which we estimate the cost of wind-source hydrogen fuel delivered to the distant city gate in year 2010, at GW scale. Ammonia, synthetic hydrocarbons, and other substances may also be attractive renewable-source energy carriers, storage media, and fuels; they are not considered in this paper. (authors)

Freedom and Responsibility in Synthetic Genomics: The Synthetic Yeast Project.

Science.gov (United States)

Sliva, Anna; Yang, Huanming; Boeke, Jef D; Mathews, Debra J H

2015-08-01

First introduced in 2011, the Synthetic Yeast Genome (Sc2.0) PROJECT is a large international synthetic genomics project that will culminate in the first eukaryotic cell (Saccharomyces cerevisiae) with a fully synthetic genome. With collaborators from across the globe and from a range of institutions spanning from do-it-yourself biology (DIYbio) to commercial enterprises, it is important that all scientists working on this project are cognizant of the ethical and policy issues associated with this field of research and operate under a common set of principles. In this commentary, we survey the current ethics and regulatory landscape of synthetic biology and present the Sc2.0 Statement of Ethics and Governance to which all members of the project adhere. This statement focuses on four aspects of the Sc2.0 PROJECT: societal benefit, intellectual property, safety, and self-governance. We propose that such project-level agreements are an important, valuable, and flexible model of self-regulation for similar global, large-scale synthetic biology projects in order to maximize the benefits and minimize potential harms. Copyright © 2015 by the Genetics Society of America.

Minimizing fouling at hydrogenated conical-tip carbon electrodes during dopamine detection in vivo.

Science.gov (United States)

Chandra, Shaneel; Miller, Anthony D; Bendavid, Avi; Martin, Philip J; Wong, Danny K Y

2014-03-04

In this paper, physically small conical-tip carbon electrodes (∼2-5 μm diameter and ∼4 μm axial length) were hydrogenated to develop a probe capable of withstanding fouling during dopamine detection in vivo. Upon hydrogenation, the resultant hydrophobic sp(3) carbon surface deters adsorption of amphiphilic lipids, proteins, and peptides present in extracellular fluid and hence minimizes electrode fouling. These hydrogenated carbon electrodes showed a 35% decrease in sensitivity but little change in the limit of detection for dopamine over a 7-day incubation in a synthetic laboratory solution containing 1.0% (v/v) caproic acid (a lipid), 0.1% (w/v) bovine serum albumin and 0.01% (w/v) cytochrome C (both are proteins), and 0.002% (w/v) human fibrinopeptide B (a peptide). Subsequently, during dopamine detection in vivo, over 70% of the dopamine oxidation current remained after the first 30 min of a 60-min experiment, and at least 50% remained over the next half-period at the hydrogenated carbon electrodes. On the basis of these results, an initial average electrode surface fouling rate of 1.2% min(-1) was estimated, which gradually declined to 0.7% min(-1). These results support minimal fouling at hydrogenated carbon electrodes applied to dopamine detection in vivo.

2012 Molecular Basis of Microbial One-Carbon Metabolism Gordon Research Conferences and Gordon Research Seminar, August 4-10,2012

Energy Technology Data Exchange (ETDEWEB)

Hanson, Thomas

2012-08-10

The 2012 Gordon Conference will present and discuss cutting-edge research in the field of microbial metabolism of C1 compounds. The conference will feature the roles and application of C1 metabolism in natural and synthetic systems at scales from molecules to ecosystems. The conference will stress molecular aspects of the unique metabolism exhibited by autotrophic bacteria, methanogens, methylotrophs, aerobic and anaerobic methanotrophs, and acetogens.

Adsorption methods for hydrogen isotope storage on zeolitic sieves

International Nuclear Information System (INIS)

Cristescu, Ioana; Cristescu, Ion; Vasut, F.; Brad, S.; Lazar, A.

2001-01-01

For hydrogen isotope separation, adsorption molecular sieves and active carbon were used. Adsorption process proceeds at liquid nitrogen and liquid hydrogen temperatures. Commercial zeolites have the same proprieties with natural zeolites, but they have a regular pore structure. They also have affinity for molecules of different size with defined shapes. Experimental results obtained at liquid nitrogen temperature (77.4 K) and liquid hydrogen revealed the efficient behaviour of the active carbon and zeolitic sieves for hydrogen isotopes temporary storage. We study adsorption of the synthetic zeolites in a wide range of temperatures and pressures and we used the molecular sieves 4A, 5A and active carbon. The 4A and 5A zeolites have a tridimensional structure with 11.4 A diameter. When the hydration water is eliminated, the material keeps a porous structure. The porous volume represents 45% from the zeolite mass for 4A and 5A sieves. The activation temperature of the zeolite and the carbon is very important for obtaining a high adsorption capacity. If the temperature used for activation is low, the structural water will be not eliminated and the adsorption capacity will be low. The excessive temperature will destroy the porous structure. The adsorption capacity for the hydrogen isotopes was calculated with the relation: A = V ads /m (cm 3 /g). The adsorption capacity and efficiency for the adsorbent materials, are given. Physical adsorption process of the hydrogen isotopes was carried out at liquid nitrogen temperature. The flux gas used in the adsorption system is composed of dry deuterium and protium. This mixture is cooled in liquid nitrogen and then is passed to the adsorbent getter at the same temperature (77.4 K). The gas flux in the adsorbent getter is 5 and 72 l/h (which correspond to 0.008 and 0.134 discharge velocity, respectively). (authors)

An obligately aerobic soil bacterium activates fermentative hydrogen production to survive reductive stress during hypoxia.

Science.gov (United States)

Berney, Michael; Greening, Chris; Conrad, Ralf; Jacobs, William R; Cook, Gregory M

2014-08-05

Oxygen availability is a major factor and evolutionary force determining the metabolic strategy of bacteria colonizing an environmental niche. In the soil, conditions can switch rapidly between oxia and anoxia, forcing soil bacteria to remodel their energy metabolism accordingly. Mycobacterium is a dominant genus in the soil, and all its species are obligate aerobes. Here we show that an obligate aerobe, the soil actinomycete Mycobacterium smegmatis, adopts an anaerobe-type strategy by activating fermentative hydrogen production to adapt to hypoxia. This process is controlled by the two-component system DosR-DosS/DosT, an oxygen and redox sensor that is well conserved in mycobacteria. We show that DosR tightly regulates the two [NiFe]-hydrogenases: Hyd3 (MSMEG_3931-3928) and Hyd2 (MSMEG_2719-2718). Using genetic manipulation and high-sensitivity GC, we demonstrate that Hyd3 facilitates the evolution of H2 when oxygen is depleted. Combined activity of Hyd2 and Hyd3 was necessary to maintain an optimal NAD(+)/NADH ratio and enhanced adaptation to and survival of hypoxia. We demonstrate that fermentatively-produced hydrogen can be recycled when fumarate or oxygen become available, suggesting Mycobacterium smegmatis can switch between fermentation, anaerobic respiration, and aerobic respiration. Hydrogen metabolism enables this obligate aerobe to rapidly meet its energetic needs when switching between microoxic and anoxic conditions and provides a competitive advantage in low oxygen environments.

Engineering of metabolic pathways by artificial enzyme channels

Directory of Open Access Journals (Sweden)

Marlene ePröschel

2015-10-01

Full Text Available Application of industrial enzymes for production of valuable chemical compounds has greatly benefited from recent developments in Systems and Synthetic Biology. Both, in vivo and in vitro systems have been established, allowing conversion of simple into complex compounds. Metabolic engineering in living cells needs to be balanced which is achieved by controlling gene expression levels, translation, scaffolding, compartmentation and flux control. In vitro applications are often hampered by limited protein stability/half-life and insufficient rates of substrate conversion. To improve stability and catalytic activity, proteins are post-translationally modified and arranged in artificial metabolic channels. Within the review article we will first discuss the supramolecular organization of enzymes in living systems and secondly summarize current and future approaches to design artificial metabolic channels by additive manufacturing for the efficient production of desired products.

Renewable Bio-Solar Hydrogen Production: The Second Generation (Part B)

Science.gov (United States)

2015-03-20

SUBJECT TERMS Biohydrogen, biofuels, cyanobacteria, photosynthesis, fermentation , transcription profiling, metabolic engineering, TCA cycle...transcription regulators, including RbcR, Fur, and ChlR, were identified and characterized, and a global model of the transcription network was...enhance hydrogen production. These data have recently been analyzed to produce a global transcription network model for this cyanobacterium [17]. At

Modular co-culture engineering, a new approach for metabolic engineering.

Science.gov (United States)

Zhang, Haoran; Wang, Xiaonan

2016-09-01

With the development of metabolic engineering, employment of a selected microbial host for accommodation of a designed biosynthetic pathway to produce a target compound has achieved tremendous success in the past several decades. Yet, increasing requirements for sophisticated microbial biosynthesis call for establishment and application of more advanced metabolic engineering methodologies. Recently, important progress has been made towards employing more than one engineered microbial strains to constitute synthetic co-cultures and modularizing the biosynthetic labor between the co-culture members in order to improve bioproduction performance. This emerging approach, referred to as modular co-culture engineering in this review, presents a valuable opportunity for expanding the scope of the broad field of metabolic engineering. We highlight representative research accomplishments using this approach, especially those utilizing metabolic engineering tools for microbial co-culture manipulation. Key benefits and major challenges associated with modular co-culture engineering are also presented and discussed. Copyright © 2016 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Synthesis of vanadium-doped palladium nanoparticles for hydrogen storage materials

Science.gov (United States)

Yamamoto, Yuki; Miyachi, Mariko; Yamanoi, Yoshinori; Minoda, Ai; Maekawa, Shunsuke; Oshima, Shinji; Kobori, Yoshihiro; Nishihara, Hiroshi

2011-12-01

Palladium-vanadium (Pd/V) alloy nanoparticles stabilized with n-pentyl isocyanide were prepared as new hydrogen storage materials by a facile polyol-based synthetic route with tetraethylene glycol and NaOH at 250 °C. The size distribution of the nanoparticles thus obtained featured two peaks at 4.0 ± 1.1 and 1.4 ± 0.3 nm in diameter, which were the mixture of Pd/V alloy and Pd nanoparticles. The ratio between the number of Pd/V and that of Pd nanoparticles was 51:49, and the Pd:V ratio of the overall product was 9:1 in wt%, indicating that the 4.0 nm Pd/V nanoparticles were composed of 81% Pd and 19% V. The inclusion of vanadium caused the increase in the d-spacing and thus expansion of lattice constant. A rapid increase in hydrogen content at low H2 pressures was observed for the Pd/V nanoparticles, and a 0.47 wt% H2 adsorption capacity was achieved under a H2 pressure of 10 MPa at 303 K. Hydrogen storage performances of Pd/V alloy nanoparticles was superior compared with Pd nanoparticles.

Platelet concentrates for transfusion-metabolic and storage aspects.

Science.gov (United States)

Farrugia, A

1994-01-01

Transfusion of platelets concentrated from donated blood is an established therapeutic modality in clinical medicine. Over the past 25 years much effort has gone into optimising the conditions for the collection, preparation and storage of platelets for transfusion. Despite significant advances, platelet production is still a costly process requiring a dedicated environment and the use of specially formulated plastic storage containers. A progressive lesion over storage limits the shelf life and the availability of donated platelets, while the need to store platelets in the donor's autologous plasma also results in a loss of valuable fresh plasma for fractionation. Recent studies have addressed the issues of platelet quality and plasma economy by examining the possibility of storing platelets in a synthetic medium. Platelets stored in a variety of crystalloid solutions have been shown to retain in vitro and in vivo properties equivalent or superior to platelets stored in autologous donor plasma. Some additional insight has been gained on the metabolic patterns of stored platelets. In particular, studies have shown that, under these conditions, platelets are unable to oxidise dextrose to any significant extent, and that dextrose is invariably broken down to lactate, irrespective of the oxygen tensions in the platelet's environment. This in turn leads to the metabolic lesion of platelet storage, whereby low pH results in loss of platelet viability. Platelets stored in synthetic dextrose-free media are capable of maintaining aerobic ATP generation, and acetate-a component of many media studied-has been shown to be metabolised by platelets. Similarly, platelets prepared from blood collected into a dextrose-free anticoagulant have satisfactory properties both when suspended in autologous plasma or in a dextrose-free synthetic medium. The requirements for storage in special, high gas-permeable, containers, and for constant agitation during storage, were both found to be

Influence of natural and synthetic vitamin C (ascorbic acid) on primary and secondary metabolites and associated metabolism in quinoa (Chenopodium quinoa Willd.) plants under water deficit regimes.

Science.gov (United States)

Aziz, Aniqa; Akram, Nudrat Aisha; Ashraf, Muhammad

2018-02-01

Phytoextracts are being widely used these days as a source of bioactive compounds for mitigating the harmful effects of abiotic stresses including drought stress. In this study, it was assessed how far foliar applied pure synthetic ascorbic acid (AsA) or natural sweet orange juice (OJ) enriched with AsA could mitigate the drought stress induced adverse effects on growth and some key metabolic processes in quinoa (Chenopodium quinoa Willd.; cultivar V 9 ) plants. Two weeks old quinoa seedlings were subjected to varying irrigation regimes as control [100% field capacity (FC)] and drought stress (60% FC, 40% FC and 20% FC). After one month of water deficit treatments, various levels of ascorbic acid (150 mg L -1 AsA or 25% OJ) besides control [distilled water (DW) and no spray (NS)] were applied as a foliar spray. After 15 days of AsA application, different physio-biochemical attributes were measured. The results showed that water deficit markedly decreased plant growth, relative water content (RWC), photosynthetic rate, total carotenoids (CAR) and total flavonoids, while it increased relative membrane permeability (RMP), intrinsic AsA content, hydrogen peroxide (H 2 O 2 ), malondialdehyde (MDA), glycinebetaine (GB), total phenolics, total soluble proteins (TSP), total free amino acids, activities of key antioxidant enzymes [superoxide dismutase (SOD), peroxidase (POD)], total soluble sugars (TSS), reducing (RS) and non-reducing sugars (NRS). Most obvious results of most of these parameters were observed at 40% and 20% FC. Foliar-applied pure 150 mg L -1 AsA and 25% OJ were found to be very effective in improving plant growth, RMP, photosynthetic rate, CAR, proline, AsA, MDA, GB, TSP, free amino acids, SOD, POD, TSS, RS, NRS and total flavonoids. It was noticed that 25% OJ enriched with AsA and other essential nutrients and biomolecules was as efficient as 150 mg L -1 AsA in reducing the adverse effects of drought stress on quinoa plants. So, it was concluded

Synthetic dosage lethality in the human metabolic network is highly predictive of tumor growth and cancer patient survival.

Science.gov (United States)

Megchelenbrink, Wout; Katzir, Rotem; Lu, Xiaowen; Ruppin, Eytan; Notebaart, Richard A

2015-09-29

Synthetic dosage lethality (SDL) denotes a genetic interaction between two genes whereby the underexpression of gene A combined with the overexpression of gene B is lethal. SDLs offer a promising way to kill cancer cells by inhibiting the activity of SDL partners of activated oncogenes in tumors, which are often difficult to target directly. As experimental genome-wide SDL screens are still scarce, here we introduce a network-level computational modeling framework that quantitatively predicts human SDLs in metabolism. For each enzyme pair (A, B) we systematically knock out the flux through A combined with a stepwise flux increase through B and search for pairs that reduce cellular growth more than when either enzyme is perturbed individually. The predictive signal of the emerging network of 12,000 SDLs is demonstrated in five different ways. (i) It can be successfully used to predict gene essentiality in shRNA cancer cell line screens. Moving to clinical tumors, we show that (ii) SDLs are significantly underrepresented in tumors. Furthermore, breast cancer tumors with SDLs active (iii) have smaller sizes and (iv) result in increased patient survival, indicating that activation of SDLs increases cancer vulnerability. Finally, (v) patient survival improves when multiple SDLs are present, pointing to a cumulative effect. This study lays the basis for quantitative identification of cancer SDLs in a model-based mechanistic manner. The approach presented can be used to identify SDLs in species and cell types in which "omics" data necessary for data-driven identification are missing.

Molecular Hydrogen as an Emerging Therapeutic Medical Gas for Neurodegenerative and Other Diseases

Directory of Open Access Journals (Sweden)

Kinji Ohno

2012-01-01

Full Text Available Effects of molecular hydrogen on various diseases have been documented for 63 disease models and human diseases in the past four and a half years. Most studies have been performed on rodents including two models of Parkinson's disease and three models of Alzheimer's disease. Prominent effects are observed especially in oxidative stress-mediated diseases including neonatal cerebral hypoxia; Parkinson's disease; ischemia/reperfusion of spinal cord, heart, lung, liver, kidney, and intestine; transplantation of lung, heart, kidney, and intestine. Six human diseases have been studied to date: diabetes mellitus type 2, metabolic syndrome, hemodialysis, inflammatory and mitochondrial myopathies, brain stem infarction, and radiation-induced adverse effects. Two enigmas, however, remain to be solved. First, no dose-response effect is observed. Rodents and humans are able to take a small amount of hydrogen by drinking hydrogen-rich water, but marked effects are observed. Second, intestinal bacteria in humans and rodents produce a large amount of hydrogen, but an addition of a small amount of hydrogen exhibits marked effects. Further studies are required to elucidate molecular bases of prominent hydrogen effects and to determine the optimal frequency, amount, and method of hydrogen administration for each human disease.

Molecular Hydrogen as an Emerging Therapeutic Medical Gas for Neurodegenerative and Other Diseases

Science.gov (United States)

Ohno, Kinji; Ito, Mikako; Ichihara, Masatoshi; Ito, Masafumi

2012-01-01

Effects of molecular hydrogen on various diseases have been documented for 63 disease models and human diseases in the past four and a half years. Most studies have been performed on rodents including two models of Parkinson's disease and three models of Alzheimer's disease. Prominent effects are observed especially in oxidative stress-mediated diseases including neonatal cerebral hypoxia; Parkinson's disease; ischemia/reperfusion of spinal cord, heart, lung, liver, kidney, and intestine; transplantation of lung, heart, kidney, and intestine. Six human diseases have been studied to date: diabetes mellitus type 2, metabolic syndrome, hemodialysis, inflammatory and mitochondrial myopathies, brain stem infarction, and radiation-induced adverse effects. Two enigmas, however, remain to be solved. First, no dose-response effect is observed. Rodents and humans are able to take a small amount of hydrogen by drinking hydrogen-rich water, but marked effects are observed. Second, intestinal bacteria in humans and rodents produce a large amount of hydrogen, but an addition of a small amount of hydrogen exhibits marked effects. Further studies are required to elucidate molecular bases of prominent hydrogen effects and to determine the optimal frequency, amount, and method of hydrogen administration for each human disease. PMID:22720117

Multiplexed genome engineering and genotyping methods applications for synthetic biology and metabolic engineering.

Science.gov (United States)

Wang, Harris H; Church, George M

2011-01-01

Engineering at the scale of whole genomes requires fundamentally new molecular biology tools. Recent advances in recombineering using synthetic oligonucleotides enable the rapid generation of mutants at high efficiency and specificity and can be implemented at the genome scale. With these techniques, libraries of mutants can be generated, from which individuals with functionally useful phenotypes can be isolated. Furthermore, populations of cells can be evolved in situ by directed evolution using complex pools of oligonucleotides. Here, we discuss ways to utilize these multiplexed genome engineering methods, with special emphasis on experimental design and implementation. Copyright © 2011 Elsevier Inc. All rights reserved.

Electrochemistry in the mimicry of oxidative drug metabolism by cytochrome P450s.

Science.gov (United States)

Nouri-Nigjeh, Eslam; Bischoff, Rainer; Bruins, Andries P; Permentier, Hjalmar P

2011-05-01

Prediction of oxidative drug metabolism at the early stages of drug discovery and development requires fast and accurate analytical techniques to mimic the in vivo oxidation reactions by cytochrome P450s (CYP). Direct electrochemical oxidation combined with mass spectrometry, although limited to the oxidation reactions initiated by charge transfer, has shown promise in the mimicry of certain CYP-mediated metabolic reactions. The electrochemical approach may further be utilized in an automated manner in microfluidics devices facilitating fast screening of oxidative drug metabolism. A wide range of in vivo oxidation reactions, particularly those initiated by hydrogen atom transfer, can be imitated through the electrochemically-assisted Fenton reaction. This reaction is based on O-O bond activation in hydrogen peroxide and oxidation by hydroxyl radicals, wherein electrochemistry is used for the reduction of molecular oxygen to hydrogen peroxide, as well as the reduction of Fe(3+) to Fe(2+). Metalloporphyrins, as surrogates for the prosthetic group in CYP, utilizing metallo-oxo reactive species, can also be used in combination with electrochemistry. Electrochemical reduction of metalloporphyrins in solution or immobilized on the electrode surface activates molecular oxygen in a manner analogous to the catalytical cycle of CYP and different metalloporphyrins can mimic selective oxidation reactions. Chemoselective, stereoselective, and regioselective oxidation reactions may be mimicked using electrodes that have been modified with immobilized enzymes, especially CYP itself. This review summarizes the recent attempts in utilizing electrochemistry as a versatile analytical and preparative technique in the mimicry of oxidative drug metabolism by CYP. © 2011 Bentham Science Publishers Ltd.

BCAA Metabolism and Insulin Sensitivity - Dysregulated by Metabolic Status?

Science.gov (United States)

Gannon, Nicholas P; Schnuck, Jamie K; Vaughan, Roger A

2018-03-01

Branched-chain amino acids (BCAAs) appear to influence several synthetic and catabolic cellular signaling cascades leading to altered phenotypes in mammals. BCAAs are most notably known to increase protein synthesis through modulating protein translation, explaining their appeal to resistance and endurance athletes for muscle hypertrophy, expedited recovery, and preservation of lean body mass. In addition to anabolic effects, BCAAs may increase mitochondrial content in skeletal muscle and adipocytes, possibly enhancing oxidative capacity. However, elevated circulating BCAA levels have been correlated with severity of insulin resistance. It is hypothesized that elevated circulating BCAAs observed in insulin resistance may result from dysregulated BCAA degradation. This review summarizes original reports that investigated the ability of BCAAs to alter glucose uptake in consequential cell types and experimental models. The review also discusses the interplay of BCAAs with other metabolic factors, and the role of excess lipid (and possibly energy excess) in the dysregulation of BCAA catabolism. Lastly, this article provides a working hypothesis of the mechanism(s) by which lipids may contribute to altered BCAA catabolism, which often accompanies metabolic disease. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Production of natural antioxidants from vegetable oil deodorizer distillates: effect of catalytic hydrogenation.

Science.gov (United States)

Pagani, María Ayelén; Baltanás, Miguel A

2010-02-01

Natural tocopherols are one of the main types of antioxidants found in living creatures, but they also have other critical biological functions. The biopotency of natural (+)-alpha-tocopherol (RRR) is 36% higher than that of the synthetic racemic mixture and 300% higher than the SRR stereoisomer. Vegetable oil deodorizer distillates (DD) are an excellent source of natural tocopherols. Catalytic hydrogenation of DD preconcentrates has been suggested as a feasible route for recovery of tocopherols in high yield. However, it is important to know whether the hydrogenation operation, as applied to these tocopherol-rich mixtures, is capable of preserving the chiral (RRR) character, which is critical to its biopotency. Fortified (i.e., (+)-alpha-tocopherol enriched) sunflower oil and methyl stearate, as well as sunflower oil DD, were fully hydrogenated using commercial Ni and Pd catalysts (120-180 degrees C; 20-60 psig). Products were analyzed by chiral HPLC. Results show that the desired chiral configuration (RRR) is fully retained. Thus, the hydrogenation route can be safely considered as a valid alternative for increasing the efficiency of tocopherol recovery processes from DDs while preserving their natural characteristics.

Radioisotopic and synthetic studies related to caroxazone metabolism in man

International Nuclear Information System (INIS)

Bernardi, L.; Coda, S.; Nicolella, V.; Vicario, G.P.; Gioia, B.; Minghetti, A.; Vigevani, A.; Arcamone, F.

1979-01-01

Labelled 2-oxo-2H-1,3-benzoxazine-3(4H)-acetamide (caroxazone), has been synthesized by condensing N-(2-hydroxylbenzyl) glycinamide with 14 C phosgene. Metabolic studies were performed administering the labelled drug to man and recovering metabolites were identified and confirmed by synthesis, namely (3,4-dihydro - 3-carboxamidomethyl-2-oxo-2H - 1,3-benzoxazin-4-yl) urea (IX), N-carboxamidomethyl o-hydroxymethylphenyl carbamate (V), 4-methoxy-2-oxo-2H - 1,3-benzoxazine-3(4H) acetamide (VIIIa), 2-oxo-2H - 1,3-benzoxazine-3(4H) acetic acid (III) and 4-hydroxy-2-oxo-2H-1,3-benzoxazine-3(4H) acetamide (IV). (orig.) 891 AJ/orig. 892 GR [de

Synthetic environments

Science.gov (United States)

Lukes, George E.; Cain, Joel M.

1996-02-01

The Advanced Distributed Simulation (ADS) Synthetic Environments Program seeks to create robust virtual worlds from operational terrain and environmental data sources of sufficient fidelity and currency to interact with the real world. While some applications can be met by direct exploitation of standard digital terrain data, more demanding applications -- particularly those support operations 'close to the ground' -- are well-served by emerging capabilities for 'value-adding' by the user working with controlled imagery. For users to rigorously refine and exploit controlled imagery within functionally different workstations they must have a shared framework to allow interoperability within and between these environments in terms of passing image and object coordinates and other information using a variety of validated sensor models. The Synthetic Environments Program is now being expanded to address rapid construction of virtual worlds with research initiatives in digital mapping, softcopy workstations, and cartographic image understanding. The Synthetic Environments Program is also participating in a joint initiative for a sensor model applications programer's interface (API) to ensure that a common controlled imagery exploitation framework is available to all researchers, developers and users. This presentation provides an introduction to ADS and the associated requirements for synthetic environments to support synthetic theaters of war. It provides a technical rationale for exploring applications of image understanding technology to automated cartography in support of ADS and related programs benefitting from automated analysis of mapping, earth resources and reconnaissance imagery. And it provides an overview and status of the joint initiative for a sensor model API.

Multiscale modelling and experimentation of hydrogen embrittlement in aerospace materials

Science.gov (United States)

Jothi, Sathiskumar

Pulse plated nickel and nickel based superalloys have been used extensively in the Ariane 5 space launcher engines. Large structural Ariane 5 space launcher engine components such as combustion chambers with complex microstructures have usually been manufactured using electrodeposited nickel with advanced pulse plating techniques with smaller parts made of nickel based superalloys joined or welded to the structure to fabricate Ariane 5 space launcher engines. One of the major challenges in manufacturing these space launcher components using newly developed materials is a fundamental understanding of how different materials and microstructures react with hydrogen during welding which can lead to hydrogen induced cracking. The main objective of this research has been to examine and interpret the effects of microstructure on hydrogen diffusion and hydrogen embrittlement in (i) nickel based superalloy 718, (ii) established and (iii) newly developed grades of pulse plated nickel used in the Ariane 5 space launcher engine combustion chamber. Also, the effect of microstructures on hydrogen induced hot and cold cracking and weldability of three different grades of pulse plated nickel were investigated. Multiscale modelling and experimental methods have been used throughout. The effect of microstructure on hydrogen embrittlement was explored using an original multiscale numerical model (exploiting synthetic and real microstructures) and a wide range of material characterization techniques including scanning electron microscopy, 2D and 3D electron back scattering diffraction, in-situ and ex-situ hydrogen charged slow strain rate tests, thermal spectroscopy analysis and the Varestraint weldability test. This research shows that combined multiscale modelling and experimentation is required for a fundamental understanding of microstructural effects in hydrogen embrittlement in these materials. Methods to control the susceptibility to hydrogen induced hot and cold cracking and

Hydrogen energy

International Nuclear Information System (INIS)

2005-03-01

This book consists of seven chapters, which deals with hydrogen energy with discover and using of hydrogen, Korean plan for hydrogen economy and background, manufacturing technique on hydrogen like classification and hydrogen manufacture by water splitting, hydrogen storage technique with need and method, hydrogen using technique like fuel cell, hydrogen engine, international trend on involving hydrogen economy, technical current for infrastructure such as hydrogen station and price, regulation, standard, prospect and education for hydrogen safety and system. It has an appendix on related organization with hydrogen and fuel cell.

One-carbon metabolism in acetogenic and sulfate-reducing bacteria

NARCIS (Netherlands)

Visser, M.

2015-01-01

ABSTRACT

One-carbon metabolism in acetogenic and sulfate-reducing bacteria

Life on earth is sustained by the constant cycling of six essential elements: oxygen, hydrogen, nitrogen,

Metal-mediated DNA base pairing: alternatives to hydrogen-bonded Watson-Crick base pairs.

Science.gov (United States)

Takezawa, Yusuke; Shionoya, Mitsuhiko

2012-12-18

With its capacity to store and transfer the genetic information within a sequence of monomers, DNA forms its central role in chemical evolution through replication and amplification. This elegant behavior is largely based on highly specific molecular recognition between nucleobases through the specific hydrogen bonds in the Watson-Crick base pairing system. While the native base pairs have been amazingly sophisticated through the long history of evolution, synthetic chemists have devoted considerable efforts to create alternative base pairing systems in recent decades. Most of these new systems were designed based on the shape complementarity of the pairs or the rearrangement of hydrogen-bonding patterns. We wondered whether metal coordination could serve as an alternative driving force for DNA base pairing and why hydrogen bonding was selected on Earth in the course of molecular evolution. Therefore, we envisioned an alternative design strategy: we replaced hydrogen bonding with another important scheme in biological systems, metal-coordination bonding. In this Account, we provide an overview of the chemistry of metal-mediated base pairing including basic concepts, molecular design, characteristic structures and properties, and possible applications of DNA-based molecular systems. We describe several examples of artificial metal-mediated base pairs, such as Cu(2+)-mediated hydroxypyridone base pair, H-Cu(2+)-H (where H denotes a hydroxypyridone-bearing nucleoside), developed by us and other researchers. To design the metallo-base pairs we carefully chose appropriate combinations of ligand-bearing nucleosides and metal ions. As expected from their stronger bonding through metal coordination, DNA duplexes possessing metallo-base pairs exhibited higher thermal stability than natural hydrogen-bonded DNAs. Furthermore, we could also use metal-mediated base pairs to construct or induce other high-order structures. These features could lead to metal-responsive functional

Molecular Cloning Designer Simulator (MCDS): All-in-one molecular cloning and genetic engineering design, simulation and management software for complex synthetic biology and metabolic engineering projects.

Science.gov (United States)

Shi, Zhenyu; Vickers, Claudia E

2016-12-01

Molecular Cloning Designer Simulator (MCDS) is a powerful new all-in-one cloning and genetic engineering design, simulation and management software platform developed for complex synthetic biology and metabolic engineering projects. In addition to standard functions, it has a number of features that are either unique, or are not found in combination in any one software package: (1) it has a novel interactive flow-chart user interface for complex multi-step processes, allowing an integrated overview of the whole project; (2) it can perform a user-defined workflow of cloning steps in a single execution of the software; (3) it can handle multiple types of genetic recombineering, a technique that is rapidly replacing classical cloning for many applications; (4) it includes experimental information to conveniently guide wet lab work; and (5) it can store results and comments to allow the tracking and management of the whole project in one platform. MCDS is freely available from https://mcds.codeplex.com.

Libraries of Synthetic TALE-Activated Promoters: Methods and Applications.

Science.gov (United States)

Schreiber, T; Tissier, A

2016-01-01

The discovery of proteins with programmable DNA-binding specificities triggered a whole array of applications in synthetic biology, including genome editing, regulation of transcription, and epigenetic modifications. Among those, transcription activator-like effectors (TALEs) due to their natural function as transcription regulators, are especially well-suited for the development of orthogonal systems for the control of gene expression. We describe here the construction and testing of libraries of synthetic TALE-activated promoters which are under the control of a single TALE with a given DNA-binding specificity. These libraries consist of a fixed DNA-binding element for the TALE, a TATA box, and variable sequences of 19 bases upstream and 43 bases downstream of the DNA-binding element. These libraries were cloned using a Golden Gate cloning strategy making them usable as standard parts in a modular cloning system. The broad range of promoter activities detected and the versatility of these promoter libraries make them valuable tools for applications in the fine-tuning of expression in metabolic engineering projects or in the design and implementation of regulatory circuits. © 2016 Elsevier Inc. All rights reserved.

Response by the AFHYPAC to the note by France Strategie of 26 August 2014 'Is there room for hydrogen in energy transition?'

International Nuclear Information System (INIS)

2014-01-01

The French Association for hydrogen and fuel cells (AFHYPAC) herein proposes a response to an article published by France Strategie which minors the possible role of hydrogen in energy transition. The authors outline that this note gives imprecise information about vehicle technology, reports conventional wisdoms without justification (about risks, interest of the power-to-gas technology, costs), and gives erroneous information. After a synthetic statement, this publication proposes a detailed response to several specific statements contained by the original note

A hydrogen economy: an answer to future energy problems. [Overview of 1974 THEME Conference

Energy Technology Data Exchange (ETDEWEB)

Seifritz, W [Eidgenoessisches Inst. fuer Reaktorforschung, Wuerenlingen (Switzerland)

1975-06-01

''The Theme was THEME''. This was the headline of The Hydrogen Economy Miami Energy Conference which was the first international conference of this type and which took place in Miami, March 18-20, 1974. For the first time, about 700 participants from all over the western world discussed all the ramifications and aspects of a hydrogen based economy. Non-fossil hydrogen, produced from water by either electrolysis or by direct use of process heat from a nuclear source is a clean, all-synthetic, automatically recyclable, and inexhaustible fuel. It may support the World's future energy requirements beyond the present self limited fossil-fuel era. A large number of papers and news were presented on this conference reflecting this effort. The following article is intended to report on the highlights of the conference and to give a survey on the present state of the art in the hydrogen field. Furthermore, the author includes his own ideas and conclusions predominantly by taking into account the trends in the development of future nuclear reactor systems and symbiotic high-temperature-reactor/breeder strategies being the primary energy input of a hydrogen economy and providing a most promising avenue for solving both the World's energy and environmental (entropy) problems.

Metabolic engineering in chemolithoautotrophic hosts for the production of fuels and chemicals.

Science.gov (United States)

Nybo, S Eric; Khan, Nymul E; Woolston, Benjamin M; Curtis, Wayne R

2015-07-01

The ability of autotrophic organisms to fix CO2 presents an opportunity to utilize this 'greenhouse gas' as an inexpensive substrate for biochemical production. Unlike conventional heterotrophic microorganisms that consume carbohydrates and amino acids, prokaryotic chemolithoautotrophs have evolved the capacity to utilize reduced chemical compounds to fix CO2 and drive metabolic processes. The use of chemolithoautotrophic hosts as production platforms has been renewed by the prospect of metabolically engineered commodity chemicals and fuels. Efforts such as the ARPA-E electrofuels program highlight both the potential and obstacles that chemolithoautotrophic biosynthetic platforms provide. This review surveys the numerous advances that have been made in chemolithoautotrophic metabolic engineering with a focus on hydrogen oxidizing bacteria such as the model chemolithoautotrophic organism (Ralstonia), the purple photosynthetic bacteria (Rhodobacter), and anaerobic acetogens. Two alternative strategies of microbial chassis development are considered: (1) introducing or enhancing autotrophic capabilities (carbon fixation, hydrogen utilization) in model heterotrophic organisms, or (2) improving tools for pathway engineering (transformation methods, promoters, vectors etc.) in native autotrophic organisms. Unique characteristics of autotrophic growth as they relate to bioreactor design and process development are also discussed in the context of challenges and opportunities for genetic manipulation of organisms as production platforms. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Metaproteomics analysis of the functional insights into microbial communities of combined hydrogen and methane production by anaerobic fermentation from reed straw.

Directory of Open Access Journals (Sweden)

Xuan Jia

Full Text Available A metaproteomic approach was used to analyse the proteins expressed and provide functional evidence of key metabolic pathways in the combined production of hydrogen and methane by anaerobic fermentation (CHMP-AF for reed straw utilisation. The functions and structures of bacteria and archaea populations show significant succession in the CHMP-AF process. There are many kinds of bacterial functional proteins, mainly belonging to phyla Firmicutes, Proteobacteria, Actinobacteria and Bacteroidetes, that are involved in carbohydrate metabolism, energy metabolism, lipid metabolism, and amino acid metabolism. Ferredoxin-NADP reductase, present in bacteria in genus Azotobacter, is an important enzyme for NADH/NAD+ equilibrium regulation in hydrogen production. The archaeal functional proteins are mainly involved in methane metabolism in energy metabolism, such as acetyl-CoA decarboxylase, and methyl-coenzyme M reductase, and the acetic acid pathway exhibited the highest proportion of the total. The archaea of genus Methanosarcina in phylum Euryarchaeota can produce methane under the effect of multi-functional proteins through acetic acid, CO2 reduction, and methyl nutrient pathways. The study demonstrates metaproteomics as a new way of uncovering community functional and metabolic activity. The combined information was used to identify the metabolic pathways and organisms crucial for lignocellulosic biomass degradation and biogas production. This also regulates the process from its protein levels and improves the efficiency of biogas production using reed straw biomass.

Metaproteomics analysis of the functional insights into microbial communities of combined hydrogen and methane production by anaerobic fermentation from reed straw

Science.gov (United States)

Yang, Yang; Wang, Yong

2017-01-01

A metaproteomic approach was used to analyse the proteins expressed and provide functional evidence of key metabolic pathways in the combined production of hydrogen and methane by anaerobic fermentation (CHMP-AF) for reed straw utilisation. The functions and structures of bacteria and archaea populations show significant succession in the CHMP-AF process. There are many kinds of bacterial functional proteins, mainly belonging to phyla Firmicutes, Proteobacteria, Actinobacteria and Bacteroidetes, that are involved in carbohydrate metabolism, energy metabolism, lipid metabolism, and amino acid metabolism. Ferredoxin-NADP reductase, present in bacteria in genus Azotobacter, is an important enzyme for NADH/NAD+ equilibrium regulation in hydrogen production. The archaeal functional proteins are mainly involved in methane metabolism in energy metabolism, such as acetyl-CoA decarboxylase, and methyl-coenzyme M reductase, and the acetic acid pathway exhibited the highest proportion of the total. The archaea of genus Methanosarcina in phylum Euryarchaeota can produce methane under the effect of multi-functional proteins through acetic acid, CO2 reduction, and methyl nutrient pathways. The study demonstrates metaproteomics as a new way of uncovering community functional and metabolic activity. The combined information was used to identify the metabolic pathways and organisms crucial for lignocellulosic biomass degradation and biogas production. This also regulates the process from its protein levels and improves the efficiency of biogas production using reed straw biomass. PMID:28817657

Opportunities in plant synthetic biology.

Science.gov (United States)

Cook, Charis; Martin, Lisa; Bastow, Ruth

2014-05-01

Synthetic biology is an emerging field uniting scientists from all disciplines with the aim of designing or re-designing biological processes. Initially, synthetic biology breakthroughs came from microbiology, chemistry, physics, computer science, materials science, mathematics, and engineering disciplines. A transition to multicellular systems is the next logical step for synthetic biologists and plants will provide an ideal platform for this new phase of research. This meeting report highlights some of the exciting plant synthetic biology projects, and tools and resources, presented and discussed at the 2013 GARNet workshop on plant synthetic biology.

Photobiological production of hydrogen: a solar energy conversion option

Energy Technology Data Exchange (ETDEWEB)

Weaver, P.; Lien, S.; Seibert, M.

1979-01-01

This literature survey of photobiological hydrogen production covers the period from its discovery in relatively pure cultures during the early 1930s to the present. The focus is hydrogen production by phototrophic organisms (and their components) which occurs at the expense of light energy and electron-donating substrates. The survey covers the major contributions in the area; however, in many cases, space has limited the degree of detail provided. Among the topics included is a brief historical overview of hydrogen metabolism in photosynthetic bacteria, eucaryotic algae, and cyanobacteria (blue--green algae). The primary enzyme systems, including hydrogenase and nitrogenase, are discussed along with the manner in which they are coupled to electron transport and the primary photochemistry of photosynthesis. A number of in vivo and in vitro photobiological hydrogen evolving schemes including photosynthetic bacterial, green algal, cyanobacterial, two-stage, and cell-free systems are examined in some detail. The remainder of the review discusses specific technical problem areas that currently limit the yield and duration of many of the systems and research that might lead to progress in these specific areas. The final section outlines, in broadest terms, future research directions necessary to develop practical photobiological hydrogen-producing systems. Both whole cell (near- to mid-term) and cell-free (long-term) systems should be emphasized. Photosynthetic bacteria currently show the most promise for near-term applied systems.

Metabolic engineering of biosynthetic pathway for production of renewable biofuels.

Science.gov (United States)

Singh, Vijai; Mani, Indra; Chaudhary, Dharmendra Kumar; Dhar, Pawan Kumar

2014-02-01

Metabolic engineering is an important area of research that involves editing genetic networks to overproduce a certain substance by the cells. Using a combination of genetic, metabolic, and modeling methods, useful substances have been synthesized in the past at industrial scale and in a cost-effective manner. Currently, metabolic engineering is being used to produce sufficient, economical, and eco-friendly biofuels. In the recent past, a number of efforts have been made towards engineering biosynthetic pathways for large scale and efficient production of biofuels from biomass. Given the adoption of metabolic engineering approaches by the biofuel industry, this paper reviews various approaches towards the production and enhancement of renewable biofuels such as ethanol, butanol, isopropanol, hydrogen, and biodiesel. We have also identified specific areas where more work needs to be done in the future.

Engineering Two-Dimensional Transition Metal Dichalcogenide Catalysts for Water-Splitting Hydrogen Generation

DEFF Research Database (Denmark)

Cao, Xianyi; Tang, Yingying; Duus, Jens Øllgaard

2017-01-01

Development of advanced energy conversion and storage technologies is essential for optimizing the integration of sustainable energy resources into current-running power grid systems. As one of the key energy-storage carriers, hydrogen (H2) possesses ultrahigh gravimetric energy density, eco...... working principles of HER electrocatalysts, and main synthetic methods of 2D TMDs based materials. We then highlight some representative 2D-TMD materials used as HER electrocatalysts and conclude with the remarks and outlook of the relevant research lines....

Natural AMPK Activators: An Alternative Approach for the Treatment and Management of Metabolic Syndrome.

Science.gov (United States)

Sharma, Hitender; Kumar, Sunil

2017-01-01

This review covers recent discoveries of phytoconstituents, herbal extracts and some semi-synthetic compounds for treating metabolic syndrome with AMPK activation as one of their mechanisms of action. Recent researches have demonstrated AMPK activation to ameliorate multiple components of metabolic syndrome by regulating a balance between anabolic and catabolic cellular reactions. The review attempts to delineate the AMPK activation by natural agents from the perspective of its functional consequences on enzymes, transcription factors and signaling molecules and also on other potential factors contributing in the amelioration of metabolic syndrome. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

A living foundry for Synthetic Biological Materials: A synthetic biology roadmap to new advanced materials

Directory of Open Access Journals (Sweden)

Rosalind A. Le Feuvre

2018-06-01

Full Text Available Society is on the cusp of harnessing recent advances in synthetic biology to discover new bio-based products and routes to their affordable and sustainable manufacture. This is no more evident than in the discovery and manufacture of Synthetic Biological Materials, where synthetic biology has the capacity to usher in a new Materials from Biology era that will revolutionise the discovery and manufacture of innovative synthetic biological materials. These will encompass novel, smart, functionalised and hybrid materials for diverse applications whose discovery and routes to bio-production will be stimulated by the fusion of new technologies positioned across physical, digital and biological spheres. This article, which developed from an international workshop held in Manchester, United Kingdom, in 2017 [1], sets out to identify opportunities in the new materials from biology era. It considers requirements, early understanding and foresight of the challenges faced in delivering a Discovery to Manufacturing Pipeline for synthetic biological materials using synthetic biology approaches. This challenge spans the complete production cycle from intelligent and predictive design, fabrication, evaluation and production of synthetic biological materials to new ways of bringing these products to market. Pathway opportunities are identified that will help foster expertise sharing and infrastructure development to accelerate the delivery of a new generation of synthetic biological materials and the leveraging of existing investments in synthetic biology and advanced materials research to achieve this goal. Keywords: Synthetic biology, Materials, Biological materials, Biomaterials, Advanced materials

Applications of computational modeling in metabolic engineering of yeast.

Science.gov (United States)

Kerkhoven, Eduard J; Lahtvee, Petri-Jaan; Nielsen, Jens

2015-02-01

Generally, a microorganism's phenotype can be described by its pattern of metabolic fluxes. Although fluxes cannot be measured directly, inference of fluxes is well established. In biotechnology the aim is often to increase the capacity of specific fluxes. For this, metabolic engineering methods have been developed and applied extensively. Many of these rely on balancing of intracellular metabolites, redox, and energy fluxes, using genome-scale models (GEMs) that in combination with appropriate objective functions and constraints can be used to predict potential gene targets for obtaining a preferred flux distribution. These methods point to strategies for altering gene expression; however, fluxes are often controlled by post-transcriptional events. Moreover, GEMs are usually not taking into account metabolic regulation, thermodynamics and enzyme kinetics. To facilitate metabolic engineering, tools from synthetic biology have emerged, enabling integration and assembly of naturally nonexistent, but well-characterized components into a living organism. To describe these systems kinetic models are often used and to integrate these systems with the standard metabolic engineering approach, it is necessary to expand the modeling of metabolism to consider kinetics of individual processes. This review will give an overview about models available for metabolic engineering of yeast and discusses their applications. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.

GENOME-BASED MODELING AND DESIGN OF METABOLIC INTERACTIONS IN MICROBIAL COMMUNITIES

Directory of Open Access Journals (Sweden)

Radhakrishnan Mahadevan

2012-10-01

With the advent of genome sequencing, omics technologies, bioinformatics and genome-scale modeling, researchers now have unprecedented capabilities to analyze and engineer the metabolism of microbial communities. The goal of this review is to summarize recent applications of genome-scale metabolic modeling to microbial communities. A brief introduction to lumped community models is used to motivate the need for genome-level descriptions of individual species and their metabolic interactions. The review of genome-scale models begins with static modeling approaches, which are appropriate for communities where the extracellular environment can be assumed to be time invariant or slowly varying. Dynamic extensions of the static modeling approach are described, and then applications of genome-scale models for design of synthetic microbial communities are reviewed. The review concludes with a summary of metagenomic tools for analyzing community metabolism and an outlook for future research.

Li4FeH6: Iron-containing complex hydride with high gravimetric hydrogen density

Directory of Open Access Journals (Sweden)

Hiroyuki Saitoh

2014-07-01

Full Text Available Li4FeH6, which has the highest gravimetric hydrogen density of iron-containing complex hydrides reported so far, is synthesized by hydrogenation of a powder mixture of iron and LiH above 6.1 GPa at 900 °C. In situ synchrotron radiation X-ray diffraction measurements reveal that while kinetics require high temperature and thus high pressure for the synthesis, Li4FeH6 is expected to be thermodynamically stable slightly below room temperature at ambient pressure; further synthetic studies to suppress the kinetic effects may enable us to synthesize Li4FeH6 at moderate pressures. Li4FeH6 can be recovered at ambient conditions where Li4FeH6 is metastable.

Sulfur metabolism in phototrophic sulfur bacteria

DEFF Research Database (Denmark)

Frigaard, Niels-Ulrik; Dahl, Christiane

2008-01-01

Phototrophic sulfur bacteria are characterized by oxidizing various inorganic sulfur compounds for use as electron donors in carbon dioxide fixation during anoxygenic photosynthetic growth. These bacteria are divided into the purple sulfur bacteria (PSB) and the green sulfur bacteria (GSB......). They utilize various combinations of sulfide, elemental sulfur, and thiosulfate and sometimes also ferrous iron and hydrogen as electron donors. This review focuses on the dissimilatory and assimilatory metabolism of inorganic sulfur compounds in these bacteria and also briefly discusses these metabolisms...... in other types of anoxygenic phototrophic bacteria. The biochemistry and genetics of sulfur compound oxidation in PSB and GSB are described in detail. A variety of enzymes catalyzing sulfur oxidation reactions have been isolated from GSB and PSB (especially Allochromatium vinosum, a representative...

Synthetic biological networks

International Nuclear Information System (INIS)

Archer, Eric; Süel, Gürol M

2013-01-01

Despite their obvious relationship and overlap, the field of physics is blessed with many insightful laws, while such laws are sadly absent in biology. Here we aim to discuss how the rise of a more recent field known as synthetic biology may allow us to more directly test hypotheses regarding the possible design principles of natural biological networks and systems. In particular, this review focuses on synthetic gene regulatory networks engineered to perform specific functions or exhibit particular dynamic behaviors. Advances in synthetic biology may set the stage to uncover the relationship of potential biological principles to those developed in physics. (review article)

A metabolic derivation of tritium transfer factors in animal products

International Nuclear Information System (INIS)

Galeriu, D.; Melintescu, A.; Crout, N. M. J.; Bersford, N. A.; Peterson, S. R.; Hess, M. van

2001-01-01

Tritium is a potentially important environmental contaminant arising from the nuclear industry. Because tritium is an isotope of hydrogen, its behaviour in the environment is controlled by the behaviour of hydrogen. Chronic releases of tritium to the atmosphere, in particular, will result in tritium-to-hydrogen (T/H) ratios in plants and animals that are more or less in equilibrium with T/H ratios in the air moisture. Tritium is thus a potentially important contaminant of plant and animal food products. The transfer of tritium from air moisture to plants is quite well understood. In contrast, although a number of regulatory agencies have published transfer coefficient values for diet tritium transfer for a limited number of animal products, a fresh evaluation of these transfers needs to be made In this paper we present an approach for the derivation of tritium transfer coefficients which is based on the metabolism of hydrogen in animals in conjunction with experimental data on tritium transfer. The derived transfer coefficients separately account for transfer to and from free (i.e. water) and organically bound tritium. The predicted transfer coefficients are compared to available data independent of model development. Agreement is good, with the exception of the transfer coefficient for transfer from tritiated water to organically bound tritium in ruminants, which may be attributable to the particular characteristics of ruminant digestion. We show that transfer coefficients will vary in response to the metabolic status of an animal (e.g. stage of lactation, digestibility of diet, etc.) and that the use of a single transfer coefficient from diet to animal product is not appropriate for tritium. It is possible to derive concentration ratio values which relate the concentration of tritiated water and organically bound tritium in an animal product to the corresponding concentrations in the animals diet. These concentration ratios are shown to be less subject to

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

Science.gov (United States)

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

2016-01-01

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

Measurement of dissolved hydrogen and hydrogen gas transfer in a hydrogen-producing reactor

Energy Technology Data Exchange (ETDEWEB)

Shizas, I.; Bagley, D.M. [Toronto Univ., ON (Canada). Dept. of Civil Engineering

2004-07-01

This paper presents a simple method to measure dissolved hydrogen concentrations in the laboratory using standard equipment and a series of hydrogen gas transfer tests. The method was validated by measuring hydrogen gas transfer parameters for an anaerobic reactor system that was purged with 10 per cent carbon dioxide and 90 per cent nitrogen using a coarse bubble diffuser stone. Liquid samples from the reactor were injected into vials and hydrogen was allowed to partition between the liquid and gaseous phases. The concentration of dissolved hydrogen was determined by comparing the headspace injections onto a gas chromatograph and a standard curve. The detection limit was 1.0 x 10{sup -5} mol/L of dissolved hydrogen. The gas transfer rate for hydrogen in basal medium and anaerobic digester sludge was used to validate the method. Results were compared with gas transfer models. In addition to monitoring dissolved hydrogen in reactor systems, this method can help improve hydrogen production potential. 1 ref., 4 figs.

Integrating the protein and metabolic engineering toolkits for next-generation chemical biosynthesis.

Science.gov (United States)

Pirie, Christopher M; De Mey, Marjan; Jones Prather, Kristala L; Ajikumar, Parayil Kumaran

2013-04-19

Through microbial engineering, biosynthesis has the potential to produce thousands of chemicals used in everyday life. Metabolic engineering and synthetic biology are fields driven by the manipulation of genes, genetic regulatory systems, and enzymatic pathways for developing highly productive microbial strains. Fundamentally, it is the biochemical characteristics of the enzymes themselves that dictate flux through a biosynthetic pathway toward the product of interest. As metabolic engineers target sophisticated secondary metabolites, there has been little recognition of the reduced catalytic activity and increased substrate/product promiscuity of the corresponding enzymes compared to those of central metabolism. Thus, fine-tuning these enzymatic characteristics through protein engineering is paramount for developing high-productivity microbial strains for secondary metabolites. Here, we describe the importance of protein engineering for advancing metabolic engineering of secondary metabolism pathways. This pathway integrated enzyme optimization can enhance the collective toolkit of microbial engineering to shape the future of chemical manufacturing.

A living foundry for Synthetic Biological Materials: A synthetic biology roadmap to new advanced materials.

Science.gov (United States)

Le Feuvre, Rosalind A; Scrutton, Nigel S

2018-06-01

Society is on the cusp of harnessing recent advances in synthetic biology to discover new bio-based products and routes to their affordable and sustainable manufacture. This is no more evident than in the discovery and manufacture of Synthetic Biological Materials , where synthetic biology has the capacity to usher in a new Materials from Biology era that will revolutionise the discovery and manufacture of innovative synthetic biological materials. These will encompass novel, smart, functionalised and hybrid materials for diverse applications whose discovery and routes to bio-production will be stimulated by the fusion of new technologies positioned across physical, digital and biological spheres. This article, which developed from an international workshop held in Manchester, United Kingdom, in 2017 [1], sets out to identify opportunities in the new materials from biology era. It considers requirements, early understanding and foresight of the challenges faced in delivering a Discovery to Manufacturing Pipeline for synthetic biological materials using synthetic biology approaches. This challenge spans the complete production cycle from intelligent and predictive design, fabrication, evaluation and production of synthetic biological materials to new ways of bringing these products to market. Pathway opportunities are identified that will help foster expertise sharing and infrastructure development to accelerate the delivery of a new generation of synthetic biological materials and the leveraging of existing investments in synthetic biology and advanced materials research to achieve this goal.

The K2/Spice Phenomenon: emergence, identification, legislation and metabolic characterization of synthetic cannabinoids in herbal incense products

Science.gov (United States)

Brents, Lisa K.; Prather, Paul L.

2014-01-01

In 2008, the European Monitoring Center for Drugs and Drug Addiction (EMCDDA) detected unregulated, psychoactive synthetic cannabinoids (SCBs) in purportedly all-natural herbal incense products (often known as K2 or Spice) that were being covertly abused as marijuana substitutes. These drugs, which include JWH-018, JWH-073 and CP-47,497, bind and activate the cannabinoid receptors CB1R and CB2R with remarkable potency and efficacy. Serious adverse effects that often require medical attention, including severe cardiovascular, gastrointestinal and psychiatric sequelae, are highly prevalent with SCB abuse. Consequently, progressively restrictive legislation in the US and Europe has banned the distribution, sale and use of prevalent SCBs, initiating cycles in which herbal incense manufacturers replace banned SCBs with newer unregulated SCBs. The contents of the numerous, diverse herbal incense products was unknown when SCB abuse first emerged. Furthermore, the pharmacology of the active components was largely uncharacterized, and confirmation of SCB use was hindered by a lack of known biomarkers. These knowledge gaps prompted scientists across multiple disciplines to rapidly (1) monitor, identify and quantify with chromatography/mass spectrometry the ever-changing contents of herbal incense products, (2) determine the metabolic pathways and major urinary metabolites of several commonly abused SCBs and (3) identify active metabolites that possibly contribute to the severe adverse effect profile of SCBs. This review comprehensively describes the emergence of SCB abuse and provides a historical account of the major case reports, legal decisions and scientific discoveries of the ″K2/Spice Phenomenon″. Hypotheses concerning potential mechanisms SCB adverse effects are proposed in this review. PMID:24063277

Modifying factors for metabolic parameters

International Nuclear Information System (INIS)

Inaba, Jiro

1990-01-01

Studies on factors which influence the metabolic parameter for calculation of radiation doses from intakes of radionuclides are very important for estimation of the doses for the general public, because the present procedures recommended by the International Commission on Radiological Protection is for occupationally exposed workers and the underlying metabolic and dosimetric models have been developed from studies on adult man and experiments on adult animals and from observations on radionuclides in physico-chemically simple form. Many factors have been reported to influence the metabolic parameters. Among them, the food-chain involvement of radionuclides and the age-dependence in humans and animals are most significant as environmental and physiological factor, respectively. In connection with the age-dependence of dose calculation, the ICRP started a new programme. They organized a Task Group on Age-Dependent Dose-Factors where relevant information on metabolic and biokinetic parameters are presently being reviewed for development of a set of dose factors for the following age-groups: infant, 1-year-old, 5-year-old, 10-year-old, 15-year-old, and ICRP Reference Man. The first stage of the work is for age-dependent integrated organ and effective dose factors for radioisotopes of the following elements: hydrogen, carbon, iodine, cesium, strontium, plutonium and americium. (author)

Synthetic biology and occupational risk.

Science.gov (United States)

Howard, John; Murashov, Vladimir; Schulte, Paul

2017-03-01

Synthetic biology is an emerging interdisciplinary field of biotechnology that involves applying the principles of engineering and chemical design to biological systems. Biosafety professionals have done an excellent job in addressing research laboratory safety as synthetic biology and gene editing have emerged from the larger field of biotechnology. Despite these efforts, risks posed by synthetic biology are of increasing concern as research procedures scale up to industrial processes in the larger bioeconomy. A greater number and variety of workers will be exposed to commercial synthetic biology risks in the future, including risks to a variety of workers from the use of lentiviral vectors as gene transfer devices. There is a need to review and enhance current protection measures in the field of synthetic biology, whether in experimental laboratories where new advances are being researched, in health care settings where treatments using viral vectors as gene delivery systems are increasingly being used, or in the industrial bioeconomy. Enhanced worker protection measures should include increased injury and illness surveillance of the synthetic biology workforce; proactive risk assessment and management of synthetic biology products; research on the relative effectiveness of extrinsic and intrinsic biocontainment methods; specific safety guidance for synthetic biology industrial processes; determination of appropriate medical mitigation measures for lentiviral vector exposure incidents; and greater awareness and involvement in synthetic biology safety by the general occupational safety and health community as well as by government occupational safety and health research and regulatory agencies.

Hydrogen production from coal gasification for effective downstream CO{sub 2} capture

Energy Technology Data Exchange (ETDEWEB)

Gnanapragasam, Nirmal V.; Reddy, Bale V.; Rosen, Marc A. [Faculty of Engineering and Applied Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, Ontario, L1H 7K4 (Canada)

2010-05-15

The coal gasification process is used in commercial production of synthetic gas as a means toward clean use of coal. The conversion of solid coal into a gaseous phase creates opportunities to produce more energy forms than electricity (which is the case in coal combustion systems) and to separate CO{sub 2} in an effective manner for sequestration. The current work compares the energy and exergy efficiencies of an integrated coal-gasification combined-cycle power generation system with that of coal gasification-based hydrogen production system which uses water-gas shift and membrane reactors. Results suggest that the syngas-to-hydrogen (H{sub 2}) system offers 35% higher energy and 17% higher exergy efficiencies than the syngas-to-electricity (IGCC) system. The specific CO{sub 2} emission from the hydrogen system was 5% lower than IGCC system. The Brayton cycle in the IGCC system draws much nitrogen after combustion along with CO{sub 2}. Thus CO{sub 2} capture and compression become difficult due to the large volume of gases involved, unlike the hydrogen system which has 80% less nitrogen in its exhaust stream. The extra electrical power consumption for compressing the exhaust gases to store CO{sub 2} is above 70% for the IGCC system but is only 4.5% for the H{sub 2} system. Overall the syngas-to-hydrogen system appears advantageous to the IGCC system based on the current analysis. (author)

Longitudinal dispersion coefficient depending on superficial velocity of hydrogen isotopes flowing in column packed with zeolite pellets at 77.4 K

Energy Technology Data Exchange (ETDEWEB)

Kotoh, K. [Faculty of Engineering, Kyushu University, Nishi-ku, Fukuoka (Japan); Graduate School of Engineering, Kyushu University, Nishi-ku, Fukuoka (Japan); Kubo, K.; Takashima, S.; Moriyama, S.T. [Graduate School of Engineering, Kyushu University, Nishi-ku, Fukuoka (Japan); Tanaka, M. [National Institute for Fusion Science, Oroshi-cho, Toki, Gifu (Japan); Sugiyama, T. [Faculty of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya (Japan)

2015-03-15

Authors have been developing a cryogenic pressure swing adsorption system for hydrogen isotope separation. In the problem of its design and operation, it is necessary to predict the concentration profiles developing in packed beds of adsorbent pellets. The profiling is affected by the longitudinal dispersion of gas flowing in packed beds, in addition to the mass transfer resistance in porous media of adsorbent pellets. In this work, an equation is derived for estimating the packed-bed dispersion coefficient of hydrogen isotopes, by analyzing the breakthrough curves of trace D{sub 2} or HD replacing H{sub 2} adsorbed in synthetic zeolite particles packed columns at the liquefied nitrogen temperature 77.4 K. Since specialized for hydrogen isotopes, this equation can be considered to estimate the dispersion coefficients more reliable for the cryogenic hydrogen isotope adsorption process, than the existing equations. (authors)

Tracking the emergence of synthetic biology.

Science.gov (United States)

Shapira, Philip; Kwon, Seokbeom; Youtie, Jan

2017-01-01

Synthetic biology is an emerging domain that combines biological and engineering concepts and which has seen rapid growth in research, innovation, and policy interest in recent years. This paper contributes to efforts to delineate this emerging domain by presenting a newly constructed bibliometric definition of synthetic biology. Our approach is dimensioned from a core set of papers in synthetic biology, using procedures to obtain benchmark synthetic biology publication records, extract keywords from these benchmark records, and refine the keywords, supplemented with articles published in dedicated synthetic biology journals. We compare our search strategy with other recent bibliometric approaches to define synthetic biology, using a common source of publication data for the period from 2000 to 2015. The paper details the rapid growth and international spread of research in synthetic biology in recent years, demonstrates that diverse research disciplines are contributing to the multidisciplinary development of synthetic biology research, and visualizes this by profiling synthetic biology research on the map of science. We further show the roles of a relatively concentrated set of research sponsors in funding the growth and trajectories of synthetic biology. In addition to discussing these analyses, the paper notes limitations and suggests lines for further work.

Printability of Synthetic Papers by Electrophotography

Directory of Open Access Journals (Sweden)

Rozália Szentgyörgyvölgyi

2010-04-01

Full Text Available This paper deals with the printability of synthetic papers by the electrophotography technique. Prints of cmyk colour fields from 20% to 100% raster tone values were printed on three types of synthetic papers (one film synthetic paper and two fiber synthetic papers. The investigation of the appearance included densitometric measurement of the cmyk prints. The results have shown differences in the optical density and optical tone value between cmyk prints made on various synthetic papers. The highest optical density and the increase of the optical tone value were observed on the film synthetic paper, where cmyk prints were more saturated. The highest abrasion resistance of cmyk prints was obtained from the fibre synthetic paper.

In situ hydrogen consumption kinetics as an indicator of subsurface microbial activity

Science.gov (United States)

Harris, S.H.; Smith, R.L.; Suflita, J.M.

2007-01-01

There are few methods available for broadly assessing microbial community metabolism directly within a groundwater environment. In this study, hydrogen consumption rates were estimated from in situ injection/withdrawal tests conducted in two geochemically varying, contaminated aquifers as an approach towards developing such a method. The hydrogen consumption first-order rates varied from 0.002 nM h-1 for an uncontaminated, aerobic site to 2.5 nM h-1 for a contaminated site where sulfate reduction was a predominant process. The method could accommodate the over three orders of magnitude range in rates that existed between subsurface sites. In a denitrifying zone, the hydrogen consumption rate (0.02 nM h-1) was immediately abolished in the presence of air or an antibiotic mixture, suggesting that such measurements may also be sensitive to the effects of environmental perturbations on field microbial activities. Comparable laboratory determinations with sediment slurries exhibited hydrogen consumption kinetics that differed substantially from the field estimates. Because anaerobic degradation of organic matter relies on the rapid consumption of hydrogen and subsequent maintenance at low levels, such in situ measures of hydrogen turnover can serve as a key indicator of the functioning of microbial food webs and may be more reliable than laboratory determinations. ?? 2007 Federation of European Microbiological Societies.

Metabolic Flexibility of Sulfate Reducing Bacteria

Directory of Open Access Journals (Sweden)

Caroline M. Plugge

2011-05-01

Full Text Available Dissimilatory sulfate-reducing prokaryotes (SRB are a very diverse group of anaerobic bacteria that are omnipresent in nature and play an imperative role in the global cycling of carbon and sulfur. In anoxic marine sediments sulfate reduction accounts for up to 50% of the entire organic mineralization in coastal and shelf ecosystems where sulfate diffuses several meters deep into the sediment. As a consequence, SRB would be expected in the sulfate-containing upper sediment layers, whereas methanogenic Archaea would be expected to succeed in the deeper sulfate-depleted layers of the sediment. Where sediments are high in organic matter, sulfate is depleted at shallow sediment depths, and biogenic methane production will occur. In the absence of sulfate, many SRB ferment organic acids and alcohols, producing hydrogen, acetate, and carbon dioxide, and may even rely on hydrogen- and acetate-scavenging methanogens to convert organic compounds to methane. SRB can establish two different life styles, and these can be termed as sulfidogenic and acetogenic, hydrogenogenic metabolism. The advantage of having different metabolic capabilities is that it raises the chance of survival in environments when electron acceptors become depleted. In marine sediments, SRB and methanogens do not compete but rather complement each other in the degradation of organic matter.Also in freshwater ecosystems with sulfate concentrations of only 10-200 μM, sulfate is consumed efficiently within the top several cm of the sediments. Here, many of the δ-Proteobacteria present have the genetic machinery to perform dissimilatory sulfate reduction, yet they have an acetogenic, hydrogenogenic way of life.In this review we evaluate the physiology and metabolic mode of SRB in relation with their environment.

South Africa's opportunity to maximise the role of nuclear power in a global hydrogen economy

Energy Technology Data Exchange (ETDEWEB)

Greyvenstein, R. [Pebble Bed Modular Reactor (PBMR) (Pty) Ltd. (South Africa)], E-mail: renee.greyvenstein@pbmr.co.za; Correia, M. [Pebble Bed Modular Reactor (PBMR) (Pty) Ltd. (South Africa)], E-mail: michael.correia@pbmr.co.za; Kriel, W. [Pebble Bed Modular Reactor (PBMR) (Pty) Ltd. (South Africa)], E-mail: willem.kriel@pbmr.us

2008-11-15

Global concern for increased energy demand, increased cost of natural gas and petroleum, energy security and environmental degradation are leading to heightened interest in using nuclear energy and hydrogen to leverage existing hydrocarbon reserves. The wasteful use of hydrocarbons can be minimised by using nuclear as a source of energy and water as a source of hydrogen. Virtually all hydrogen today is produced from fossil fuels, which give rise to CO{sub 2} emissions. Hydrogen can be cleanly produced from water (without CO{sub 2} pollution) by using nuclear energy to generate the required electricity and/or process heat to split the water molecule. Once the clean hydrogen has been produced, it can be used as feedstock to fuel cell technologies, or in the nearer term as feedstock to a coal-to-liquids process to produce cleaner synthetic liquid fuels. Clean liquid fuels from coal - using hydrogen generated from nuclear energy - is an intermediate step for using hydrogen to reduce pollution in the transport sector; simultaneously addressing energy security concerns. Several promising water-splitting technologies have been identified. Thermo-chemical water-splitting and high-temperature steam electrolysis technologies require process temperatures in the range of 850 deg. C and higher for the efficient production of hydrogen. The pebble bed modular reactor (PBMR), under development in South Africa, is ideally suited to generate both high-temperature process heat and electricity for the production of hydrogen. This paper will discuss South Africa's opportunity to maximise the use of its nuclear technology and national resources in a global hydrogen economy.

Dependence of hydrogen-induced lattice defects and hydrogen embrittlement of cold-drawn pearlitic steels on hydrogen trap state, temperature, strain rate and hydrogen content

International Nuclear Information System (INIS)

Doshida, Tomoki; Takai, Kenichi

2014-01-01

The effects of the hydrogen state, temperature, strain rate and hydrogen content on hydrogen embrittlement susceptibility and hydrogen-induced lattice defects were evaluated for cold-drawn pearlitic steel that absorbed hydrogen in two trapping states. Firstly, tensile tests were carried out under various conditions to evaluate hydrogen embrittlement susceptibility. The results showed that peak 2 hydrogen, desorbed at temperatures above 200 °C as determined by thermal desorption analysis (TDA), had no significant effect on hydrogen embrittlement susceptibility. In contrast, hydrogen embrittlement susceptibility increased in the presence of peak 1 hydrogen, desorbed from room temperature to 200 °C as determined by TDA, at temperatures higher than −30 °C, at lower strain rates and with higher hydrogen content. Next, the same effects on hydrogen-induced lattice defects were also evaluated by TDA using hydrogen as a probe. Peak 2 hydrogen showed no significant effect on either hydrogen-induced lattice defects or hydrogen embrittlement susceptibility. It was found that hydrogen-induced lattice defects formed under the conditions where hydrogen embrittlement susceptibility increased. This relationship indicates that hydrogen embrittlement susceptibility was higher under the conditions where the formation of hydrogen-induced lattice defects tended to be enhanced. Since hydrogen-induced lattice defects formed by the interaction between hydrogen and strain were annihilated by annealing at a temperature of 200 °C, they were presumably vacancies or vacancy clusters. One of the common atomic-level changes that occur in cold-drawn pearlitic steel showing higher hydrogen embrittlement susceptibility is the formation of vacancies and vacancy clusters

Evolvable synthetic neural system

Science.gov (United States)

Curtis, Steven A. (Inventor)

2009-01-01

An evolvable synthetic neural system includes an evolvable neural interface operably coupled to at least one neural basis function. Each neural basis function includes an evolvable neural interface operably coupled to a heuristic neural system to perform high-level functions and an autonomic neural system to perform low-level functions. In some embodiments, the evolvable synthetic neural system is operably coupled to one or more evolvable synthetic neural systems in a hierarchy.

MHD power generation for the synthetic-fuels industry

International Nuclear Information System (INIS)

Jones, M.S. Jr.

1982-01-01

The integration of open cycle MHD with various processes for the recovery of hydrocarbons for heavy oil deposits, oil sands, and oil shales are examined along with its use in producing medium Btu gas, synthetic natural gas and solvent refined coal. The major features of the MHD cycle which are of interest are: (a) the ability to produce hydrogen through the shift reaction by introducing H 2 O into the substoichiometric combustion product flow exiting the MHD diffuser, (b) the use of high temperature waste heat in the MHD exhaust, and (c) the ability of the seed in the MHD flow to remove sulfur from the combustion products. Therefore the use of the MHD cycle allows coal to be used in an environmentally acceptable manner in place of hydrocarbons which are now used to produce process heat and hydrogen. The appropriate plant sizes are in the range of 25 to 50 MWe and the required MHD generator enthalpy extraction efficiencies are low. Sale of electricity produced, over and above that used in the process, can provide a revenue stream which can improve the economics of the hydrocarbon processing. This, coupled with the replacement of coal for hydrocarbons in certain phases of the process, should improve the overall economics, while not requiring a high level of performance by the MHD components. Therefore, this area should be an early target of opportunity for the commercialization of MHD

Effects of oral contraceptive agents and sex steroids on carbohydrate metabolism.

Science.gov (United States)

Kalkhoff, R K

1972-01-01

The article offers a general interpretation of the influence of oral contraceptive agents on glucose tolerance, emphasizing comparisons of synthetic sex hormones. Although there are conflicting reports on steroid-induced diabetes in normal women, their glucose curves are often higher when under oral contraceptive treatment, suggesting that oral contraceptives may induce a form of subclinical diabetes melitus that is reversible. Evidence from diabetic women suggests definite deliterious effects from contraceptive administration. Estradiol, estriol, and estrone may improve glucose tolerance in nondiabetic women and reduce insulin requirements in diabetics. Progesterone has little effect on carbohydrate tolerance, as did synthetic progestin. Conjugated equine estrogens (equilenine or Premarin) may provoke mild to moderate deterioration of carbohydrate tolerance. Parenterally administered natural estrogens and orally administered synthetic derivatives appear to differ sharply in their effects. Sex hormones' effects on carbohydrate metabolism likely involve interactions with insulin and endogenous glucocorticoids.

Rewriting the Metabolic Blueprint: Advances in Pathway Diversification in Microorganisms

Directory of Open Access Journals (Sweden)

Gazi Sakir Hossain

2018-02-01

Full Text Available Living organisms have evolved over millions of years to fine tune their metabolism to create efficient pathways for producing metabolites necessary for their survival. Advancement in the field of synthetic biology has enabled the exploitation of these metabolic pathways for the production of desired compounds by creating microbial cell factories through metabolic engineering, thus providing sustainable routes to obtain value-added chemicals. Following the past success in metabolic engineering, there is increasing interest in diversifying natural metabolic pathways to construct non-natural biosynthesis routes, thereby creating possibilities for producing novel valuable compounds that are non-natural or without elucidated biosynthesis pathways. Thus, the range of chemicals that can be produced by biological systems can be expanded to meet the demands of industries for compounds such as plastic precursors and new antibiotics, most of which can only be obtained through chemical synthesis currently. Herein, we review and discuss novel strategies that have been developed to rewrite natural metabolic blueprints in a bid to broaden the chemical repertoire achievable in microorganisms. This review aims to provide insights on recent approaches taken to open new avenues for achieving biochemical production that are beyond currently available inventions.

Rewriting the Metabolic Blueprint: Advances in Pathway Diversification in Microorganisms.

Science.gov (United States)

Hossain, Gazi Sakir; Nadarajan, Saravanan Prabhu; Zhang, Lei; Ng, Tee-Kheang; Foo, Jee Loon; Ling, Hua; Choi, Won Jae; Chang, Matthew Wook

2018-01-01

Living organisms have evolved over millions of years to fine tune their metabolism to create efficient pathways for producing metabolites necessary for their survival. Advancement in the field of synthetic biology has enabled the exploitation of these metabolic pathways for the production of desired compounds by creating microbial cell factories through metabolic engineering, thus providing sustainable routes to obtain value-added chemicals. Following the past success in metabolic engineering, there is increasing interest in diversifying natural metabolic pathways to construct non-natural biosynthesis routes, thereby creating possibilities for producing novel valuable compounds that are non-natural or without elucidated biosynthesis pathways. Thus, the range of chemicals that can be produced by biological systems can be expanded to meet the demands of industries for compounds such as plastic precursors and new antibiotics, most of which can only be obtained through chemical synthesis currently. Herein, we review and discuss novel strategies that have been developed to rewrite natural metabolic blueprints in a bid to broaden the chemical repertoire achievable in microorganisms. This review aims to provide insights on recent approaches taken to open new avenues for achieving biochemical production that are beyond currently available inventions.

Feasible metabolisms in high pH springs of the Philippines.

Science.gov (United States)

Cardace, Dawn; Meyer-Dombard, D'Arcy R; Woycheese, Kristin M; Arcilla, Carlo A

2015-01-01

A field campaign targeting high pH, H2-, and CH4-emitting serpentinite-associated springs in the Zambales and Palawan Ophiolites of the Philippines was conducted in 2012-2013, and enabled description of several springs sourced in altered pillow basalts, gabbros, and peridotites. We combine field observations of pH, temperature, conductivity, dissolved oxygen, and oxidation-reduction potential with analyses of major ions, dissolved inorganic carbon, dissolved organic carbon, and dissolved gas phases in order to model the activities of selected phases important to microbial metabolism, and to rank feasible metabolic reactions based on energy yield. We document changing geochemical inventories in these springs between sampling years, and examine how the environment supports or prevents the function of certain microbial metabolisms. In all, this geochemistry-based assessment of feasible metabolisms indicates methane cycling, hydrogen oxidation, some iron and sulfur metabolisms, and ammonia oxidation are feasible reactions in this continental site of serpentinization.

JWH-018 ω-OH, a shared hydroxy metabolite of the two synthetic cannabinoids JWH-018 and AM-2201, undergoes oxidation by alcohol dehydrogenase and aldehyde dehydrogenase enzymes in vitro forming the carboxylic acid metabolite

DEFF Research Database (Denmark)

Holm, Niels Bjerre; Noble, Carolina; Linnet, Kristian

2016-01-01

Synthetic cannabinoids are new psychoactive substances (NPS) acting as agonists at the cannabinoid receptors. The aminoalkylindole-type synthetic cannabinoid naphthalen-1-yl-(1-pentylindol-3-yl)methanone (JWH-018) was among the first to appear on the illicit drug market and its metabolism has bee...

Gaining electricity from in situ oxidation of hydrogen produced by fermentative cellulose degradation.

Science.gov (United States)

Niessen, J; Schröder, U; Harnisch, F; Scholz, F

2005-01-01

To exploit the fermentative hydrogen generation and direct hydrogen oxidation for the generation of electric current from the degradation of cellulose. Utilizing the metabolic activity of the mesophilic anaerobe Clostridium cellulolyticum and the thermophilic Clostridium thermocellum we show that electricity generation is possible from cellulose fermentation. The current generation is based on an in situ oxidation of microbially synthesized hydrogen at platinum-poly(tetrafluoroaniline) (Pt-PTFA) composite electrodes. Current densities of 130 mA l(-1) (with 3 g cellulose per litre medium) were achieved in poised potential experiments under batch and semi-batch conditions. The presented results show that electricity generation is possible by the in situ oxidation of hydrogen, product of the anaerobic degradation of cellulose by cellulolytic bacteria. For the first time, it is shown that an insoluble complex carbohydrate like cellulose can be used for electricity generation in a microbial fuel cell. The concept represents a first step to the utilization of macromolecular biomass components for microbial electricity generation.

Non-photosynthetic plastids as hosts for metabolic engineering

DEFF Research Database (Denmark)

Mellor, Silas Busck; Behrendorff, James Bruce Yarnton H; Nielsen, Agnieszka Janina Zygadlo

2018-01-01

Using plants as hosts for production of complex, high-value compounds and therapeutic proteins has gained increasing momentum over the past decade. Recent advances in metabolic engineering techniques using synthetic biology have set the stage for production yields to become economically attractive......, but more refined design strategies are required to increase product yields without compromising development and growth of the host system. The ability of plant cells to differentiate into various tissues in combination with a high level of cellular compartmentalization represents so far the most...... in green tissues, have proven to be suitable for high yield protein and bio-compound production. Unfortunately, chloroplast manipulation often affects photosynthetic efficiency and therefore plant fitness. In this respect, plastids of non-photosynthetic tissues, which have focused metabolisms for synthesis...

Engineering strategy of yeast metabolism for higher alcohol production

Directory of Open Access Journals (Sweden)

Shimizu Hiroshi

2011-09-01

Full Text Available Abstract Background While Saccharomyces cerevisiae is a promising host for cost-effective biorefinary processes due to its tolerance to various stresses during fermentation, the metabolically engineered S. cerevisiae strains exhibited rather limited production of higher alcohols than that of Escherichia coli. Since the structure of the central metabolism of S. cerevisiae is distinct from that of E. coli, there might be a problem in the structure of the central metabolism of S. cerevisiae. In this study, the potential production of higher alcohols by S. cerevisiae is compared to that of E. coli by employing metabolic simulation techniques. Based on the simulation results, novel metabolic engineering strategies for improving higher alcohol production by S. cerevisiae were investigated by in silico modifications of the metabolic models of S. cerevisiae. Results The metabolic simulations confirmed that the high production of butanols and propanols by the metabolically engineered E. coli strains is derived from the flexible behavior of their central metabolism. Reducing this flexibility by gene deletion is an effective strategy to restrict the metabolic states for producing target alcohols. In contrast, the lower yield using S. cerevisiae originates from the structurally limited flexibility of its central metabolism in which gene deletions severely reduced cell growth. Conclusions The metabolic simulation demonstrated that the poor productivity of S. cerevisiae was improved by the introduction of E. coli genes to compensate the structural difference. This suggested that gene supplementation is a promising strategy for the metabolic engineering of S. cerevisiae to produce higher alcohols which should be the next challenge for the synthetic bioengineering of S. cerevisiae for the efficient production of higher alcohols.

Hydrogen sensor

Science.gov (United States)

Duan, Yixiang; Jia, Quanxi; Cao, Wenqing

2010-11-23

A hydrogen sensor for detecting/quantitating hydrogen and hydrogen isotopes includes a sampling line and a microplasma generator that excites hydrogen from a gas sample and produces light emission from excited hydrogen. A power supply provides power to the microplasma generator, and a spectrometer generates an emission spectrum from the light emission. A programmable computer is adapted for determining whether or not the gas sample includes hydrogen, and for quantitating the amount of hydrogen and/or hydrogen isotopes are present in the gas sample.

Distribution of hydrogen-metabolizing bacteria in alfalfa field soil

International Nuclear Information System (INIS)

Cunningham, S.D.; Kapulnik, Y.; Phillips, D.A.

1986-01-01

H 2 evolved by alfalfa root nodules during the process of N 2 fixation may be an important factor influencing the distribution of soil bacteria. To test this hypothesis under field conditions, over 700 bacterial isolates were obtained from fallow soil or from the 3-mm layer of soil surrounding alfalfa (Medicago sativa L.) root nodules, alfalfa roots, or bindweed (Convolvulus arvensis L.) roots. Bacteria were isolated under either aerobic or microaerophilic conditions and were tested for their capacity to metabolize H 2 . Isolates showing net H 2 uptake and 3 H 2 incorporation activity under laboratory conditions were assigned a Hup + phenotype, whereas organisms with significant H 2 output capacity were designated as a Hout + phenotype. Under aerobic isolation conditions two Hup + isolates were obtained, whereas under microaerophilic conditions five Hup + and two Hout + isolates were found. The nine isolates differed on the basis of 24 standard bacteriological characteristics or fatty acid composition. Five of the nine organisms were isolated from soil around root nodules, whereas the other four were found distributed among the other three soil environments. On the basis of the microaerophilic isolations, 4.8% of the total procaryotic isolates from soil around root nodules were capable of oxidizing H 2 , and 1.2% could produce H 2 . Two of the Hup + isolates were identified as Rhizobium meliloti by root nodulation tests, but the fact that none of the isolates reduced C 2 H 2 under the assay conditions suggested that the H 2 metabolism traits were associated with various hydrogenase systems rather than with nitrogenase activity

Continuous synthesis of methanol: heterogeneous hydrogenation of ethylene carbonate over Cu/HMS catalysts in a fixed bed reactor system.

Science.gov (United States)

Chen, Xi; Cui, Yuanyuan; Wen, Chao; Wang, Bin; Dai, Wei-Lin

2015-09-18

Continuous fixed-bed catalytic hydrogenation of ethylene carbonate (EC) to methanol and ethylene glycol (EG), an emerging synthetic process of methanol via indirect conversion of CO2, was successfully performed over Cu/HMS catalysts prepared by the ammonia evaporation (AE) method. The catalysts possessed superb performance with a conversion of 100% and a selectivity to methanol of 74%.

Sulfur metabolism in Escherichia coli and related bacteria: facts and fiction.

Science.gov (United States)

Sekowska, A; Kung, H F; Danchin, A

2000-04-01

Living organisms are composed of macromolecules made of hydrogen, carbon, nitrogen, oxygen, phosphorus and sulfur. Much work has been devoted to the metabolism of the first five elements, but much remains to be understood about sulfur metabolism. We review here the situation in Escherichia coli and related bacteria, where more than one hundred genes involved in sulfur metabolism have already been discovered in this organism. Examination of the genome suggests that many more will be found, especially genes involved in regulation, scavenging of sulfur containing molecules and synthesis of coenzymes or prosthetic groups. Furthermore, the involvement of methionine as the universal start of proteins as well as that of its derivative S-adenosylmethionine in a vast variety of cell processes argue in favour of a major importance of sulfur metabolism in all organisms.

Hail hydrogen

International Nuclear Information System (INIS)

Hairston, D.

1996-01-01

After years of being scorned and maligned, hydrogen is finding favor in environmental and process applications. There is enormous demand for the industrial gas from petroleum refiners, who need in creasing amounts of hydrogen to remove sulfur and other contaminants from crude oil. In pulp and paper mills, hydrogen is turning up as hydrogen peroxide, displacing bleaching agents based on chlorine. Now, new technologies for making hydrogen have the industry abuzz. With better capabilities of being generated onsite at higher purity levels, recycled and reused, hydrogen is being prepped for a range of applications, from waste reduction to purification of Nylon 6 and hydrogenation of specialty chemicals. The paper discusses the strong market demand for hydrogen, easier routes being developed for hydrogen production, and the use of hydrogen in the future

Thermodynamic Driving Force of Hydrogen on Rumen Microbial Metabolism: A Theoretical Investigation.

Science.gov (United States)

van Lingen, Henk J; Plugge, Caroline M; Fadel, James G; Kebreab, Ermias; Bannink, André; Dijkstra, Jan

2016-01-01

Hydrogen is a key product of rumen fermentation and has been suggested to thermodynamically control the production of the various volatile fatty acids (VFA). Previous studies, however, have not accounted for the fact that only thermodynamic near-equilibrium conditions control the magnitude of reaction rate. Furthermore, the role of NAD, which is affected by hydrogen partial pressure (PH2), has often not been considered. The aim of this study was to quantify the control of PH2 on reaction rates of specific fermentation pathways, methanogenesis and NADH oxidation in rumen microbes. The control of PH2 was quantified using the thermodynamic potential factor (FT), which is a dimensionless factor that corrects a predicted kinetic reaction rate for the thermodynamic control exerted. Unity FT was calculated for all glucose fermentation pathways considered, indicating no inhibition of PH2 on the production of a specific type of VFA (e.g., acetate, propionate and butyrate) in the rumen. For NADH oxidation without ferredoxin oxidation, increasing PH2 within the rumen physiological range decreased FT from unity to zero for different NAD+ to NADH ratios and pH of 6.2 and 7.0, which indicates thermodynamic control of PH2. For NADH oxidation with ferredoxin oxidation, increasing PH2 within the rumen physiological range decreased FT from unity at pH of 7.0 only. For the acetate to propionate conversion, FT increased from 0.65 to unity with increasing PH2, which indicates thermodynamic control. For propionate to acetate and butyrate to acetate conversions, FT decreased to zero below the rumen range of PH2, indicating full thermodynamic suppression. For methanogenesis by archaea without cytochromes, FT differed from unity only below the rumen range of PH2, indicating no thermodynamic control. This theoretical investigation shows that thermodynamic control of PH2 on individual VFA produced and associated yield of hydrogen and methane cannot be explained without considering NADH

Thermodynamic Driving Force of Hydrogen on Rumen Microbial Metabolism: A Theoretical Investigation.

Directory of Open Access Journals (Sweden)

Henk J van Lingen

Full Text Available Hydrogen is a key product of rumen fermentation and has been suggested to thermodynamically control the production of the various volatile fatty acids (VFA. Previous studies, however, have not accounted for the fact that only thermodynamic near-equilibrium conditions control the magnitude of reaction rate. Furthermore, the role of NAD, which is affected by hydrogen partial pressure (PH2, has often not been considered. The aim of this study was to quantify the control of PH2 on reaction rates of specific fermentation pathways, methanogenesis and NADH oxidation in rumen microbes. The control of PH2 was quantified using the thermodynamic potential factor (FT, which is a dimensionless factor that corrects a predicted kinetic reaction rate for the thermodynamic control exerted. Unity FT was calculated for all glucose fermentation pathways considered, indicating no inhibition of PH2 on the production of a specific type of VFA (e.g., acetate, propionate and butyrate in the rumen. For NADH oxidation without ferredoxin oxidation, increasing PH2 within the rumen physiological range decreased FT from unity to zero for different NAD+ to NADH ratios and pH of 6.2 and 7.0, which indicates thermodynamic control of PH2. For NADH oxidation with ferredoxin oxidation, increasing PH2 within the rumen physiological range decreased FT from unity at pH of 7.0 only. For the acetate to propionate conversion, FT increased from 0.65 to unity with increasing PH2, which indicates thermodynamic control. For propionate to acetate and butyrate to acetate conversions, FT decreased to zero below the rumen range of PH2, indicating full thermodynamic suppression. For methanogenesis by archaea without cytochromes, FT differed from unity only below the rumen range of PH2, indicating no thermodynamic control. This theoretical investigation shows that thermodynamic control of PH2 on individual VFA produced and associated yield of hydrogen and methane cannot be explained without

Slave nodes and the controllability of metabolic networks

International Nuclear Information System (INIS)

Kim, Dong-Hee; Motter, Adilson E

2009-01-01

Recent work on synthetic rescues has shown that the targeted deletion of specific metabolic genes can often be used to rescue otherwise non-viable mutants. This raises a fundamental biophysical question: to what extent can the whole-cell behavior of a large metabolic network be controlled by constraining the flux of one or more reactions in the network? This touches upon the issue of the number of degrees of freedom contained by one such network. Using the metabolic network of Escherichia coli as a model system, here we address this question theoretically by exploring not only reaction deletions, but also a continuum of all possible reaction expression levels. We show that the behavior of the metabolic network can be largely manipulated by the pinned expression of a single reaction. In particular, a relevant fraction of the metabolic reactions exhibits canalizing interactions, in that the specification of one reaction flux determines cellular growth as well as the fluxes of most other reactions in optimal steady states. The activity of individual reactions can thus be used as surrogates to monitor and possibly control cellular growth and other whole-cell behaviors. In addition to its implications for the study of control processes, our methodology provides a new approach to study how the integrated dynamics of the entire metabolic network emerges from the coordinated behavior of its component parts.

Synthetic Folic Acid Supplementation during Pregnancy Increases the Risk of Neonatal Jaundice in Newborns

OpenAIRE

Somayeh Zaminpira; Sorush Niknamian

2017-01-01

Folate is easily and naturally absorbed and utilized by the body when it is metabolized in the small intestines. On the other hand, folic acid, which was first introduced around the 1940s and added to the prenatal supplements of pregnant women, requires the presence of a specific enzyme named dihydrofolate reductase, which is relatively rare in the body especially during pregnancy. The reason why synthetic form of folic acid supplementation by pregnant women should be replaced by natural fola...

Synthetic Cathinones ("Bath Salts")

Science.gov (United States)

... Alcohol Club Drugs Cocaine Fentanyl Hallucinogens Inhalants Heroin Marijuana MDMA (Ecstasy/Molly) Methamphetamine Opioids Over-the-Counter Medicines Prescription Medicines Steroids (Anabolic) Synthetic Cannabinoids (K2/Spice) Synthetic Cathinones (Bath Salts) Tobacco/ ...

Therapeutic Implications of Targeting Energy Metabolism in Breast Cancer

Directory of Open Access Journals (Sweden)

Meena K. Sakharkar

2013-01-01

Full Text Available PPARs are ligand activated transcription factors. PPARγ agonists have been reported as a new and potentially efficacious treatment of inflammation, diabetes, obesity, cancer, AD, and schizophrenia. Since cancer cells show dysregulation of glycolysis they are potentially manageable through changes in metabolic environment. Interestingly, several of the genes involved in maintaining the metabolic environment and the central energy generation pathway are regulated or predicted to be regulated by PPARγ. The use of synthetic PPARγ ligands as drugs and their recent withdrawal/restricted usage highlight the lack of understanding of the molecular basis of these drugs, their off-target effects, and their network. These data further underscores the complexity of nuclear receptor signalling mechanisms. This paper will discuss the function and role of PPARγ in energy metabolism and cancer biology in general and its emergence as a promising therapeutic target in breast cancer.

Development of a combined bio-hydrogen- and methane-production unit using dark fermentation

Energy Technology Data Exchange (ETDEWEB)

Brunstermann, R.; Widmann, R. [Duisburg-Essen Univ. (Germany). Dept. of Urban Water and Waste Management

2010-07-01

Hydrogen is regarded as a source of energy of the future. Currently, hydrogen is produced, predominantly, by electrolysis of water by using electricity or by stream reforming of natural gas. So both methods are based on fossil fuels. If the used electricity is recovered from renewable recourses, hydrogen produced by water electrolysis may be a clean solution. At present, the production of hydrogen by biological processes finds more and more attention world far. The biology provides a wide range of approaches to produce hydrogen, including bio-photolysis as well as photo-fermentation and dark-fermentation. Currently these biological technologies are not suitable for solving every day energy problems [1]. But the dark-fermentation is a promising approach to produce hydrogen in a sustainable way and was already examined in some projects. At mesophilic conditions this process provides a high yield of hydrogen by less energy demand, [2]. Short hydraulic retention times (HRT) and high metabolic rates are advantages of the process. The incomplete transformation of the organic components into various organic acids is a disadvantage. Thus a second process step is required. Therefore the well known biogas-technique is used to degrade the organic acids predominantly acetic and butyric acid from the hydrogen-production unit into CH{sub 4} and CO{sub 2}. This paper deals with the development of a combined hydrogen and methane production unit using dark fermentation at mesophilic conditions. The continuous operation of the combined hydrogen and methane production out of DOC loaded sewages and carbohydrate rich biowaste is necessary for the examination of the technical and economical implementation. The hydrogen step shows as first results hydrogen concentration in the biogas between 40 % and 60 %.The operating efficiency of the combined production of hydrogen and methane shall be checked as a complete system. (orig.)

Quantifying complexity in metabolic engineering using the LASER database

Directory of Open Access Journals (Sweden)

James D. Winkler

2016-12-01

Full Text Available We previously introduced the LASER database (Learning Assisted Strain EngineeRing, https://bitbucket.org/jdwinkler/laser_release (Winkler et al. 2015 to serve as a platform for understanding past and present metabolic engineering practices. Over the past year, LASER has been expanded by 50% to include over 600 engineered strains from 450 papers, including their growth conditions, genetic modifications, and other information in an easily searchable format. Here, we present the results of our efforts to use LASER as a means for defining the complexity of a metabolic engineering “design”. We evaluate two complexity metrics based on the concepts of construction difficulty and novelty. No correlation is observed between expected product yield and complexity, allowing minimization of complexity without a performance trade-off. We envision the use of such complexity metrics to filter and prioritize designs prior to implementation of metabolic engineering efforts, thereby potentially reducing the time, labor, and expenses of large-scale projects. Possible future developments based on an expanding LASER database are then discussed. Keywords: Metabolic engineering, Synthetic biology, Standardization, Design tools

Molecular Imaging in Synthetic Biology, and Synthetic Biology in Molecular Imaging.

Science.gov (United States)

Gilad, Assaf A; Shapiro, Mikhail G

2017-06-01

Biomedical synthetic biology is an emerging field in which cells are engineered at the genetic level to carry out novel functions with relevance to biomedical and industrial applications. This approach promises new treatments, imaging tools, and diagnostics for diseases ranging from gastrointestinal inflammatory syndromes to cancer, diabetes, and neurodegeneration. As these cellular technologies undergo pre-clinical and clinical development, it is becoming essential to monitor their location and function in vivo, necessitating appropriate molecular imaging strategies, and therefore, we have created an interest group within the World Molecular Imaging Society focusing on synthetic biology and reporter gene technologies. Here, we highlight recent advances in biomedical synthetic biology, including bacterial therapy, immunotherapy, and regenerative medicine. We then discuss emerging molecular imaging approaches to facilitate in vivo applications, focusing on reporter genes for noninvasive modalities such as magnetic resonance, ultrasound, photoacoustic imaging, bioluminescence, and radionuclear imaging. Because reporter genes can be incorporated directly into engineered genetic circuits, they are particularly well suited to imaging synthetic biological constructs, and developing them provides opportunities for creative molecular and genetic engineering.

New designer drugs (synthetic cannabinoids and synthetic cathinones): review of literature.

Science.gov (United States)

Cottencin, Olivier; Rolland, Benjamin; Karila, Laurent

2014-01-01

New designer drugs (synthetic cannabinoids and synthetic cathinones) are new "legal highs" that are sold online for recreational public or private use. Synthetic cannabinoids are psychoactive herbal and chemical products that mimic the effects of cannabis when used. These drugs are available on the Internet or in head shops as incense or air fresheners to circumvent the law. Cathinone is a naturally occurring beta-ketone amphetamine analog found in the leaves of the Catha edulis plant. Synthetic cathinones are phenylalkylamine derivatives that may possess amphetamine-like properties. These drugs are sold online as bath salts. Designer drugs are often labeled as "not for human consumption" to circumvent drug abuse legislation. The absence of legal risks, the ease of obtaining these drugs, the moderate cost, and the availability via the Internet are the main features that attract users, but the number of intoxicated people presenting with emergencies is increasing. There is evidence that negative health and social consequences may affect recreational and chronic users. The addictive potential of designer drugs is not negligible.

An integrated system for hydrogen and methane production during landfill leachate treatment

Energy Technology Data Exchange (ETDEWEB)

Hafez, H.M.; Nakhla, G.; El Naggar, H. [Western Ontario Univ., London, ON (Canada). Dept. of Civil and Environmental Engineering

2009-07-01

This paper described a patent-pending integrated waste-to-energy system that includes a novel biohydrogen reactor with a gravity settler and a second stage conventional anaerobic digester for the production of methane gas. This chemical-free process was tested using a synthetic wastewater/leachate solution at 37 degrees C for 45 days. During the experimental period, the biohydrogenator steadily produced hydrogen (H{sub 2}) with no methane. The maximum hydrogen yield was 400 ml H{sub 2}/g glucose with an average of 345 ml H{sub 2}/g glucose, as compared to 141 and 118 ml H{sub 2}/g glucose for two consecutive runs done in parallel using a conventional continuously stirrer tank reactor. The maximum and average hydrogen production rates in the biohydrogen reactor with gravity settler were 22 and 19 L H{sub 2}/day, the maximum yield was 2.8 mol H{sub 2} /mol glucose higher than 1.6-2.3 mol H{sub 2}/mol glucose reported for continuous-flow reactors. The methane yield for the second stage approached a maximum value of 426 ml methane/g chemical oxygen demand (COD) removed.

Current status of synthetic epikeratoplasty.

Science.gov (United States)

Thompson, K P; Hanna, K; Waring, G O; Gipson, I; Liu, Y; Gailitis, R P; Johnson-Wint, B; Green, K

1991-01-01

Many of the deficiencies with human tissue epikeratoplasty might be improved by the use of a suitable synthetic lenticule. Potential biomaterials for epikeratoplasty include collagen (types I, III, or IV), collagen-hydrogel copolymers, bioactive synthetics, and coated hydrogels. The biomaterial must be engineered to achieve strict specifications of optical clarity, support of epithelial migration and adhesion, permeability to solutes, and stability to corneal proteases. Attaching synthetic lenticules to the cornea without cutting Bowman's layer by adhesives, laser welding, or direct adhesion may also improve the efficacy of synthetic epikeratoplasty.

Tissue Harmonic Synthetic Aperture Imaging

DEFF Research Database (Denmark)

Rasmussen, Joachim

The main purpose of this PhD project is to develop an ultrasonic method for tissue harmonic synthetic aperture imaging. The motivation is to advance the field of synthetic aperture imaging in ultrasound, which has shown great potentials in the clinic. Suggestions for synthetic aperture tissue...... system complexity compared to conventional synthetic aperture techniques. In this project, SASB is sought combined with a pulse inversion technique for 2nd harmonic tissue harmonic imaging. The advantages in tissue harmonic imaging (THI) are expected to further improve the image quality of SASB...

Life after the synthetic cell

DEFF Research Database (Denmark)

Rasmussen, Steen

2010-01-01

Nature asked eight synthetic-biology experts about the implications for science and society of the “synthetic cell” made by the J. Craig Venter Institute (JCVI). The institute's team assembled, modified and implanted a synthesized genome into a DNA-free bacterial shell to make a self-replicating ......Nature asked eight synthetic-biology experts about the implications for science and society of the “synthetic cell” made by the J. Craig Venter Institute (JCVI). The institute's team assembled, modified and implanted a synthesized genome into a DNA-free bacterial shell to make a self...

Special document: which energies for tomorrow? Fossil, renewable, nuclear, hydrogen energies; the CEA of Saclay at the heart of the research; energy, greenhouse effect, climate; Dossier special: quelles energies pour demain? Energies fossiles, renouvelables, nucleaires, hydrogene; le Centre CEA de Saclay au coeur de la recherche; energie, effet de serre, climat

Energy Technology Data Exchange (ETDEWEB)

Anon

2003-04-01

The Cea devotes many research programs in the energy domain and especially in the development of new energetic solutions: hydrogen program, photovoltaic program, energy conservation domain and improvement of energy production systems. In this framework, this document presents synthetical information on the France situation in the world energy space and on the Cea Saclay researches. The energy policy and the electric power in France, the fossil energies, the nuclear energy, the renewable energies, the hydrogen and the fuel cell, the greenhouse effect and the climatology are detailed. (A.L.B.)

Design, Optimization and Application of Small Molecule Biosensor in Metabolic Engineering.

Science.gov (United States)

Liu, Yang; Liu, Ye; Wang, Meng

2017-01-01

The development of synthetic biology and metabolic engineering has painted a great future for the bio-based economy, including fuels, chemicals, and drugs produced from renewable feedstocks. With the rapid advance of genome-scale modeling, pathway assembling and genome engineering/editing, our ability to design and generate microbial cell factories with various phenotype becomes almost limitless. However, our lack of ability to measure and exert precise control over metabolite concentration related phenotypes becomes a bottleneck in metabolic engineering. Genetically encoded small molecule biosensors, which provide the means to couple metabolite concentration to measurable or actionable outputs, are highly promising solutions to the bottleneck. Here we review recent advances in the design, optimization and application of small molecule biosensor in metabolic engineering, with particular focus on optimization strategies for transcription factor (TF) based biosensors.

Metabolic Engineering of Oleaginous Yeasts for Production of Fuels and Chemicals

Directory of Open Access Journals (Sweden)

Shuobo Shi

2017-11-01

Full Text Available Oleaginous yeasts have been increasingly explored for production of chemicals and fuels via metabolic engineering. Particularly, there is a growing interest in using oleaginous yeasts for the synthesis of lipid-related products due to their high lipogenesis capability, robustness, and ability to utilize a variety of substrates. Most of the metabolic engineering studies in oleaginous yeasts focused on Yarrowia that already has plenty of genetic engineering tools. However, recent advances in systems biology and synthetic biology have provided new strategies and tools to engineer those oleaginous yeasts that have naturally high lipid accumulation but lack genetic tools, such as Rhodosporidium, Trichosporon, and Lipomyces. This review highlights recent accomplishments in metabolic engineering of oleaginous yeasts and recent advances in the development of genetic engineering tools in oleaginous yeasts within the last 3 years.

Proceedings of Synthetic Biology: Engineering, Evolution and Design (SEED) Conference 2015

Energy Technology Data Exchange (ETDEWEB)

Silver, Pamela [Harvard Univ., Cambridge, MA (United States); SEED 2015 Conference Chair; Flach, Evan [American Institute of Chemical Engineers; SEED 2015 Conference Organizer

2016-10-27

Synthetic Biology is an emerging discipline that seeks to accelerate the process of engineering biology. As such, the tools are broadly applicable to application areas, including chemicals and biofuels, materials, medicine and agriculture. A characteristic of the field is to look holistically at cellular design, from sensing and genetic circuitry to the manipulation of cellular processes and actuators, to controlling metabolism, to programming multicellular behaviors. Further, the types of cells that are manipulated are broad, from in vitro systems to microbes and fungi to mammalian and plant cells and living animals. Many of the projects in synthetic biology seek to move biochemical functions across organisms. The field is highly interdisciplinary with faculty and students spread across departments that focus on engineering (biological, chemical, electrical, mechanical, civil, computer science) and basic science (biology and systems biology, chemistry, physics). While there have been many one-off workshops and meeting on synthetic biology, the 2014 Synthetic Biology: Engineering, Evolution and Design (SEED) was the first of an annual conference series that serves as a reliable place to pull together the involved disciplines in order to organize and exchange advances in the science and technology in the field. Further, the SEED conferences have a strong focus on industry, with many companies represented and actively participating. A number of these companies have started major efforts in synthetic biology including large companies (e.g., Pfizer, Novartis, Dow, Dupont, BP, Total), smaller companies have recently gone public (e.g., Amyris, Gevo, Intrexon), and many start-ups (e.g., Teslagen, Refactored Materials, Pivot, Genomatica). There are a number of loosely affiliated Synthetic Biology Centers, including ones at MIT, Boston University, UCSD, UCSF, UC-Berkeley, Imperial College, Oxford, and ETH. SEED 2015 will serve as the primary meeting at which international

Hydrogen molecules and hydrogen-related defects in crystalline silicon

Science.gov (United States)

Fukata, N.; Sasaki, S.; Murakami, K.; Ishioka, K.; Nakamura, K. G.; Kitajima, M.; Fujimura, S.; Kikuchi, J.; Haneda, H.

1997-09-01

We have found that hydrogen exists in molecular form in crystalline silicon treated with hydrogen atoms in the downstream of a hydrogen plasma. The vibrational Raman line of hydrogen molecules is observed at 4158 cm-1 for silicon samples hydrogenated between 180 and 500 °C. The assignment of the Raman line is confirmed by its isotope shift to 2990 cm-1 for silicon treated with deuterium atoms. The Raman intensity has a maximum for hydrogenation at 400 °C. The vibrational Raman line of the hydrogen molecules is broad and asymmetric. It consists of at least two components, possibly arising from hydrogen molecules in different occupation sites in crystalline silicon. The rotational Raman line of hydrogen molecules is observed at 590 cm-1. The Raman band of Si-H stretching is observed for hydrogenation temperatures between 100 and 500 °C and the intensity has a maximum for hydrogenation at 250 °C.

Fusion energy applied to synthetic fuel production: a report to the DOE Division of Magnetic Fusion Energy based on a preliminary study by an ad-hoc advisory group

International Nuclear Information System (INIS)

Booth, L.A.

1977-10-01

The general conclusion is that the potential for utilization of fusion energy for synthetic fuel production is favorable. Three basic methods of hydrogen production are identified: high-temperature electrolysis, thermochemical cycles, and direct radiolysis. Combinations of these and their use as in combined cycles for electric power generation are considered

Living GenoChemetics by hyphenating synthetic biology and synthetic chemistry in vivo.

Science.gov (United States)

Sharma, Sunil V; Tong, Xiaoxue; Pubill-Ulldemolins, Cristina; Cartmell, Christopher; Bogosyan, Emma J A; Rackham, Emma J; Marelli, Enrico; Hamed, Refaat B; Goss, Rebecca J M

2017-08-09

Marrying synthetic biology with synthetic chemistry provides a powerful approach toward natural product diversification, combining the best of both worlds: expediency and synthetic capability of biogenic pathways and chemical diversity enabled by organic synthesis. Biosynthetic pathway engineering can be employed to insert a chemically orthogonal tag into a complex natural scaffold affording the possibility of site-selective modification without employing protecting group strategies. Here we show that, by installing a sufficiently reactive handle (e.g., a C-Br bond) and developing compatible mild aqueous chemistries, synchronous biosynthesis of the tagged metabolite and its subsequent chemical modification in living culture can be achieved. This approach can potentially enable many new applications: for example, assay of directed evolution of enzymes catalyzing halo-metabolite biosynthesis in living cells or generating and following the fate of tagged metabolites and biomolecules in living systems. We report synthetic biological access to new-to-nature bromo-metabolites and the concomitant biorthogonal cross-coupling of halo-metabolites in living cultures.Coupling synthetic biology and chemical reactions in cells is a challenging task. The authors engineer bacteria capable of generating bromo-metabolites, develop a mild Suzuki-Miyaura cross-coupling reaction compatible with cell growth and carry out the cross-coupling chemistry in live cell cultures.

Hydrogen concentration control utilizing a hydrogen permeable membrane

International Nuclear Information System (INIS)

Keating, S.J. Jr.

1976-01-01

The concentration of hydrogen in a fluid mixture is controlled to a desired concentration by flowing the fluid through one chamber of a diffusion cell separated into two chambers by a hydrogen permeable membrane. A gradient of hydrogen partial pressure is maintained across the membrane to cause diffusion of hydrogen through the membrane to maintain the concentration of hydrogen in the fluid mixture at the predetermined level. The invention has particular utility for the purpose of injecting into and/or separating hydrogen from the reactor coolant of a nuclear reactor system

Co-pyrolysis of wood biomass and synthetic polymers mixtures

Energy Technology Data Exchange (ETDEWEB)

Sharypov, V.I.; Beregovtsova, N.G.; Kuznetsov, B.N.; Baryshnikov, S.V. [Institute of Chemistry and Chemical Technology SB RAS, K. Marx Str., Krasnoyarsk 660049 (Russian Federation); Cebolla, V.L. [Instituto de Carboquimica, CSIC, Zaragoza (Spain); Weber, J.V.; Collura, S.; Finqueneisel, G.; Zimny, T. [Laboratoire de Chimie et Applications, Universite de Metz, IUT, rue V. Demange, 57500 Saint Avold (France)

2006-06-01

The pyrolysis in a hydrogen atmosphere of pine wood and synthetic polymers (polyethylene and polypropylene) mixtures was studied in a rotating autoclave. The effects of reaction temperature, wood/polymers mixture composition and catalysts, on the mixtures conversion into liquids and gases were established and discussed. The used catalysts were pyrrhotite and haematite materials activated by mechanochemical treatment. In the co-liquefaction processes the interaction between fragments of wood and polymers thermal decomposition took place. This results in non-additive increase of the wood/polymers conversion degree by 10-15wt.% and of the yield of distillate fractions by 14-19wt.%. Iron ore materials were found catalytically active in the process of hydropyrolysis of wood/polymers mixtures. By using these catalysts a significant increase of the distillable liquids amounts (by 14-21wt.%) and a sharp decrease of olefins and cycloparaffins content (by approximately two to three times) were observed. (author)

Metabolic response of Geobacter sulfurreducens towards electron donor/acceptor variation

Directory of Open Access Journals (Sweden)

Lovley Derek R

2010-11-01

Full Text Available Abstract Background Geobacter sulfurreducens is capable of coupling the complete oxidation of organic compounds to iron reduction. The metabolic response of G. sulfurreducens towards variations in electron donors (acetate, hydrogen and acceptors (Fe(III, fumarate was investigated via 13C-based metabolic flux analysis. We examined the 13C-labeling patterns of proteinogenic amino acids obtained from G. sulfurreducens cultured with 13C-acetate. Results Using 13C-based metabolic flux analysis, we observed that donor and acceptor variations gave rise to differences in gluconeogenetic initiation, tricarboxylic acid cycle activity, and amino acid biosynthesis pathways. Culturing G. sulfurreducens cells with Fe(III as the electron acceptor and acetate as the electron donor resulted in pyruvate as the primary carbon source for gluconeogenesis. When fumarate was provided as the electron acceptor and acetate as the electron donor, the flux analysis suggested that fumarate served as both an electron acceptor and, in conjunction with acetate, a carbon source. Growth on fumarate and acetate resulted in the initiation of gluconeogenesis by phosphoenolpyruvate carboxykinase and a slightly elevated flux through the oxidative tricarboxylic acid cycle as compared to growth with Fe(III as the electron acceptor. In addition, the direction of net flux between acetyl-CoA and pyruvate was reversed during growth on fumarate relative to Fe(III, while growth in the presence of Fe(III and acetate which provided hydrogen as an electron donor, resulted in decreased flux through the tricarboxylic acid cycle. Conclusions We gained detailed insight into the metabolism of G. sulfurreducens cells under various electron donor/acceptor conditions using 13C-based metabolic flux analysis. Our results can be used for the development of G. sulfurreducens as a chassis for a variety of applications including bioremediation and renewable biofuel production.

The pH of buffers based on 2-amino-2-hydroxymethyl-1,3-propanediol (`tris') in synthetic sea water

Science.gov (United States)

DelValls, T. A.; Dickson, A. G.

1998-09-01

E.m.f. measurements were made over the temperature range 273.15-318.15 K, and at five salinities from 20 to 40, using the cell Pt( s) H2( g, p°) BH+ and B in synthetic sea water AgCl( s) Ag( s) Pt( s) where p°=101.325 kPa, and BH + and B are the conjugate acid-base pair of 2-amino-2hydroxymethyl-1,3-propanediol ('tris') - each present at a concentration of 0.04 mol kg -1. The results were used to assign pH values based on the 'total' hydrogen ion scale to such buffer solutions based on this acid-base pair. Additional measurements were made over a range of buffer concentrations at a salinity of 35; these were used to calculate the stoichiometric (ionic medium) dissociation constant for 'tris-H +' in synthetic sea water.

Creating biological nanomaterials using synthetic biology

International Nuclear Information System (INIS)

Rice, MaryJoe K; Ruder, Warren C

2014-01-01

Synthetic biology is a new discipline that combines science and engineering approaches to precisely control biological networks. These signaling networks are especially important in fields such as biomedicine and biochemical engineering. Additionally, biological networks can also be critical to the production of naturally occurring biological nanomaterials, and as a result, synthetic biology holds tremendous potential in creating new materials. This review introduces the field of synthetic biology, discusses how biological systems naturally produce materials, and then presents examples and strategies for incorporating synthetic biology approaches in the development of new materials. In particular, strategies for using synthetic biology to produce both organic and inorganic nanomaterials are discussed. Ultimately, synthetic biology holds the potential to dramatically impact biological materials science with significant potential applications in medical systems. (review)

Creating biological nanomaterials using synthetic biology.

Science.gov (United States)

Rice, MaryJoe K; Ruder, Warren C

2014-02-01

Synthetic biology is a new discipline that combines science and engineering approaches to precisely control biological networks. These signaling networks are especially important in fields such as biomedicine and biochemical engineering. Additionally, biological networks can also be critical to the production of naturally occurring biological nanomaterials, and as a result, synthetic biology holds tremendous potential in creating new materials. This review introduces the field of synthetic biology, discusses how biological systems naturally produce materials, and then presents examples and strategies for incorporating synthetic biology approaches in the development of new materials. In particular, strategies for using synthetic biology to produce both organic and inorganic nanomaterials are discussed. Ultimately, synthetic biology holds the potential to dramatically impact biological materials science with significant potential applications in medical systems.

Synthetic Defects for Vibrothermography

Science.gov (United States)

Renshaw, Jeremy; Holland, Stephen D.; Thompson, R. Bruce; Eisenmann, David J.

2010-02-01

Synthetic defects are an important tool used for characterizing the performance of nondestructive evaluation techniques. Viscous material-filled synthetic defects were developed for use in vibrothermography (also known as sonic IR) as a tool to improve inspection accuracy and reliability. This paper describes how the heat-generation response of these VMF synthetic defects is similar to the response of real defects. It also shows how VMF defects can be applied to improve inspection accuracy for complex industrial parts and presents a study of their application in an aircraft engine stator vane.

Synthetic biology: Emerging bioengineering in Indonesia

Science.gov (United States)

Suhandono, Sony

2017-05-01

The development of synthetic biology will shape the new era of science and technology. It is an emerging bioengineering technique involving genetic engineering which can alter the phenotype and behavior of the cell or the new product. Synthetic biology may produce biomaterials, drugs, vaccines, biosensors, and even a recombinant secondary metabolite used in herbal and complementary medicine, such as artemisinin, a malaria drug which is usually extracted from the plant Artemisia annua. The power of synthetic biology has encouraged scientists in Indonesia, and is still in early development. This paper also covers some research from an Indonesian research institute in synthetic biology such as observing the production of bio surfactants and the enhanced production of artemisinin using a transient expression system. Synthetic biology development in Indonesia may also be related to the iGEM competition, a large synthetic biology research competition which was attended by several universities in Indonesia. The application of synthetic biology for drug discovery will be discussed.

Hydrogen Evolution and Sludge Suspension During the Preparation of the First Batch of Sludge at the Savannah River Site

International Nuclear Information System (INIS)

Hay, M.S.; Lee, E.D.

1995-01-01

The first batch of High Level Radioactive Sludge for the Defense Waste Processing Facility is being prepared in two 4.9 million liter waste tanks. The preparation involves removing water soluble salts by washing (water addition, sludge suspension, settling and decantation). Sludge suspension is accomplished using long shafted slurry pumps that are mounted on rotating turntables. During the sludge suspension runs in 1993 and 1994, the slurry pumps' cleaning radius was determined to be less than that expected from previous determinations using synthetic sludge in a full size waste tank mockup. Hydrogen concentrations in the tanks' vapor space were monitored during the sludge suspension activities. As expected, the initial agitation of the sludge increased the hydrogen concentration, however, with the controls in place the hydrogen concentration was maintained below seven percent of the lower flammability limit

Effect of exogenous electron shuttles on growth and fermentative metabolism in Clostridium sp. BC1

Energy Technology Data Exchange (ETDEWEB)

Yarlagadda V. N.; Francis A.; Gupta, A.; Dodge, C. J.

2012-03-01

In this study, the influence exogenous electron shuttles on the growth and glucose fermentative metabolism of Clostridium sp. BC1 was investigated. Bicarbonate addition to mineral salts (MS) medium accelerated growth and glucose fermentation which shifted acidogenesis (acetic- and butyric-acids) towards solventogenesis (ethanol and butanol). Addition of ferrihydrite, anthraquinone disulfonate, and nicotinamide adenine dinucleotide in bicarbonate to growing culture showed no significant influence on fermentative metabolism. In contrast, methyl viologen (MV) enhanced ethanol- and butanol-production by 28- and 12-fold, respectively with concomitant decrease in hydrogen, acetic- and butyric-acids compared to MS medium. The results show that MV addition affects hydrogenase activity with a significant reduction in hydrogen production and a shift in the direction of electron flow towards enhanced production of ethanol and butanol.