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Ethanol Production By Zymomonas Mobilis 8b Utilizing Sugar Maple And Jerusalem Artichoke Hydrolysates As Carbon Sources
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Book Synopsis Ethanol Production by Zymomonas Mobilis 8b Utilizing Sugar Maple and Jerusalem Artichoke Hydrolysates as Carbon Sources by : Christopher J. Addona
Download or read book Ethanol Production by Zymomonas Mobilis 8b Utilizing Sugar Maple and Jerusalem Artichoke Hydrolysates as Carbon Sources written by Christopher J. Addona and published by . This book was released on 2011 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Ethanol Production by Zymomonas Mobilis Using Different Carbon Sources by : Wing Hin Lee
Download or read book Ethanol Production by Zymomonas Mobilis Using Different Carbon Sources written by Wing Hin Lee and published by . This book was released on 2002 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Fuel Ethanol Production from Sugarcane by : Thalita Peixoto Basso
Download or read book Fuel Ethanol Production from Sugarcane written by Thalita Peixoto Basso and published by BoD – Books on Demand. This book was released on 2019-01-23 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers a broad understanding of bioethanol production from sugarcane, although a few other substrates, except corn, will also be mentioned. The 10 chapters are grouped in five sections. The Fuel Ethanol Production from Sugarcane in Brazil section consists of two chapters dealing with the first-generation ethanol Brazilian industrial process. The Strategies for Sugarcane Bagasse Pretreatment section deals with emerging physicochemical methods for biomass pretreatment, and the non-conventional biomass source for lignocellulosic ethanol production addresses the potential of weed biomass as alternative feedstock. In the Recent Approaches for Increasing Fermentation Efficiency of Lignocellulosic Ethanol section, potential and research progress using thermophile bacteria and yeasts is presented, taking advantage of microorganisms involved in consolidating or simultaneous hydrolysis and fermentation processes. Finally, the Recent Advances in Ethanol Fermentation section presents the use of cold plasma and hydrostatic pressure to increase ethanol production efficiency. Also in this section the use of metabolic-engineered autotrophic cyanobacteria to produce ethanol from carbon dioxide is mentioned.
Book Synopsis Natural Sources Substrates for Ethanol Production by Zymomonas Mobilis by : Bonnie L. Crowder
Download or read book Natural Sources Substrates for Ethanol Production by Zymomonas Mobilis written by Bonnie L. Crowder and published by . This book was released on 1987 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Metabolic Engineering of Zymomonas Mobilis for Improved Production of Ethanol from Lignocelluloses by : Manoj Agrawal
Download or read book Metabolic Engineering of Zymomonas Mobilis for Improved Production of Ethanol from Lignocelluloses written by Manoj Agrawal and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Ethanol from lignocellulosic biomass is a promising alternative to rapidly depleting oil reserves. However, natural recalcitrance of lignocelluloses to biological and chemical treatments presents major engineering challenges in designing an ethanol conversion process. Current methods for pretreatment and hydrolysis of lignocelluloses generate a mixture of pentose (C5) and hexose (C6) sugars, and several microbial growth inhibitors such as acetic acid and phenolic compounds. Hence, an efficient ethanol production process requires a fermenting microorganism not only capable of converting mixed sugars to ethanol with high yield and productivity, but also having high tolerance to inhibitors. Although recombinant bacteria and yeast strains have been developed, ethanol yield and productivity from C5 sugars in the presence of inhibitors remain low and need to be further improved for a commercial ethanol production. The overarching objective of this work is to transform Zymomonas mobilis into an efficient whole-cell biocatalyst for ethanol production from lignocelluloses. Z. mobilis, a natural ethanologen, is ideal for this application but xylose (a C5 sugar) is not its 'natural' substrate. Back in 1995, researches at National Renewable Energy Laboratory (NREL) had managed to overcome this obstacle by metabolically engineering Z. mobilis to utilize xylose. However, even after more than a decade of research, xylose fermentation by Z. mobilis is still inefficient compared to that of glucose. For example, volumetric productivity of ethanol from xylose fermentation is 3- to 4- fold lower than that from glucose fermentation. Further reduction or complete inhibition of xylose fermentation occurs under adverse conditions. Also, high concentrations of xylose do not get metabolized completely. Thus, improvement in xylose fermentation by Z. mobilis is required. In this work, xylose fermentation in a metabolically engineered Z. mobilis was markedly improved by applying the technique of adaptive mutation. The adapted strain was able to grow on 10% (w/v) xylose and rapidly ferment xylose to ethanol within 2 days and retained high ethanol yield. Similarly, in mixed glucose-xylose fermentation, the strain produced a total of 9% (w/v) ethanol from two doses of 5% glucose and 5% xylose (or a total of 10% glucose and 10% xylose). Investigation was done to identify the molecular basis for efficient biocatalysis. An altered xylitol metabolism with reduced xylitol formation, increased xylitol tolerance and higher xylose isomerase activity were found to contribute towards improvement in xylose fermentation. Lower xylitol production in adapted strain was due to a single mutation in ZMO0976 gene, which drastically lowered the reductase activity of ZMO0976 protein. ZMO0976 was characterized as a novel aldo-keto reductase capable of reducing xylose, xylulose, benzaldehyde, furfural, 5-hydroxymethyl furfural, and acetaldehyde, but not glucose or fructose. It exhibited nearly 150-times higher affinity with benzaldehyde than xylose. Knockout of ZMO0976 was found to facilitate the establishment of xylose fermentation in Z. mobilis ZM4. Equipped with molecular level understanding of the biocatalytic process and insight into Z. mobilis central carbon metabolism, further genetic engineering of Z. mobilis was undertaken to improve the fermentation of sugars and lignocellulosic hydrolysates. These efforts culminated in construction of a strain capable of fermenting glucose-xylose mixture in presence of high concentration of acetic acid and another strain with a partially operational EMP pathway.
Book Synopsis Fuel Ethanol Production from Glucose Using Zymomonas Mobilis in a Membrane Recycle Fermentor by : Kumail Huseini Khorakiwala
Download or read book Fuel Ethanol Production from Glucose Using Zymomonas Mobilis in a Membrane Recycle Fermentor written by Kumail Huseini Khorakiwala and published by . This book was released on 1985 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Regulatory Circuits to Program Metabolism of Zymomonas Mobilis for Advanced Cellulosic Biofuels Production by : Yang Liu
Download or read book Regulatory Circuits to Program Metabolism of Zymomonas Mobilis for Advanced Cellulosic Biofuels Production written by Yang Liu and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Zymomonas mobilis is a potential organism for microbial biofuel production with attractive properties such as extraordinarily fast glycolysis and ethanol production. Production of advanced biofuels, such as butanol and isobutanol, is envisioned with Z. mobilis as a promising host. Z. mobilis grows exclusively through its efficient ethanol fermentation, which makes it difficult to achieve high flux into desired engineered pathways. In order to understand the physiological roles of ethanol fermentation and create strategies to divert carbon flux into production of chemicals and advanced biofuels, a Z. mobilis strain with regulated pyruvate decarboxylase (Pdc) expression was constructed. Growth, biochemical, and metabolomic experiments indicated that Pdc is essential for ethanologenic growth of Z. mobilis for redox balance and maintenance of fast glycolysis. For central carbon flux redirection, all flux can be redirected to a 2,3-butanediol pathway for which respiration maintains redox balance and the engineered 2,3-butanediol pathway allows growth without Pdc. Anaerobically, flux can be redirected to redox-balanced lactate or isobutanol pathways with ≥65% overall yield from glucose, where initial isobutanol titers reached 5 g/L. Subsequent improvements in expression of isobutanologenic enzymes allowed production up to 17 g isobutanol/L in Z. mobilis in 24 h. However, the current pathway can not support IBA-dependent growth in Z. moblis. Future optimization of the isobutanol pathway is still required. Biosensor regulatory systems, such as quorum sensing and metabolite sensing, offer practical approaches to control large-scale production of chemicals and biofuels. A xylose biosensor based on Bacillus subtlis XylR was engineered in Z. mobilis, capable of inducing gene expression at low xylose concentration. A xylose-sensing dual metabolic control circuit was constructed in Z. mobilis. Using this circuit, isobutanol pathway expression in Z. mobilis can be induced in the presence of xylose and pdc expression can be partially repressed by CRISPRi to achieve carbon flux redirection to isobutanol production. The partial pdc knockdown allowed growth and ethanol production at reduced rates and improved isobutanol production up to 3 g/L (~36% of theoretical yield from glucose) in rich medium. The circuit was also function in dilute switchgrass hydrolysate, where the engineered strain produced ~1.3 g IBA/L. Hundreds of biochemical reactions require NADH and NAD+ cofactors and their ratio is a key metabolic marker of cellular state. A genetically-encoded ratiometric biosensor for NADH/NAD+ based on redox-responsive bacterial transcription factor Rex was engineered in E. coli, which enabled non-invasive measurement of cellular redox state. The redox sensor was used to investigate the effect of removing respiratory chain enzymes on NADH/NAD+ ratio during aerobiosis. We found that the NADH/NAD+ ratio increased in five of the nine mutants by over three-fold compared to wild type, including an NADH dehydrogenase double mutant with six-fold elevation. We also found that among several common carbon sources, E. coli grown on acetate exhibited higher NADH/NAD+ ratios compared to E. coli grown on glucose. As a proof-of-concept for high-throughput redox screening, we were able to enrich high NADH mutants present at 1 in 10,000 among wild-type cells in a biosensor-guided, pooled screen. Thus, our Rex biosensor-reporter enabled facile, non-invasive, high-throughput redox measurement to understand and engineer redox metabolism.
Book Synopsis Ethanol Production by Enzymatic Hydrolysis and Fermentation of Uncooked Cassava Starch Using Zymomonas Mobilis by : Hamdan Abdul-Manap
Download or read book Ethanol Production by Enzymatic Hydrolysis and Fermentation of Uncooked Cassava Starch Using Zymomonas Mobilis written by Hamdan Abdul-Manap and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis A Kinetic Study of Ethanol Production by Zymomonas Mobilis by : Robert Mark Worden
Download or read book A Kinetic Study of Ethanol Production by Zymomonas Mobilis written by Robert Mark Worden and published by . This book was released on 1982 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Continuous Production of Ethanol by Use of Flocculent Zymomonas Mobilis by :
Download or read book Continuous Production of Ethanol by Use of Flocculent Zymomonas Mobilis written by and published by . This book was released on 1982 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Improved means and process for producing ethanol by fermentation are provided. Another object of the invention is to produce ethanol in a continuous-flow process by means of a biological catalyst that can be retained in a continuous-flow reactor vessel without being bonded to or held within a support material. An additional object of the invention is to provide a fermentation reactor vessel wherein disturbance of the desirable plug flow of sugar solution is minimized. These objects are attained by the preferred apparatus and process of the invention which utilize a newly-discovered flocculent strain of Zymomonas mobilis for converting sugar to ethanol in a continuous flow-type reactor vessel. The flow rate of a sugar-containing solution through a column containing the floc-forming strain of Z. mobilis is adjusted so that a sufficient conversion of sugar to ethanol is achieved in the column and the flocculent Z. mobilis is not washed away in effluent from the column. Carbon dioxide gas generated by the fermentation process is vented from a plurality of points spaced along an inclined column in which the process is conducted, thus minimizing disturbance of the plug flow of liquid by this gas.
Book Synopsis Ethanol Production Using Zymomonas Mobilis in a Cross-linked Immobilized Cell Reactor by : Robert David Waldron
Download or read book Ethanol Production Using Zymomonas Mobilis in a Cross-linked Immobilized Cell Reactor written by Robert David Waldron and published by . This book was released on 1988 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Enhanced Bioethanol Production by Zymomonas Mobilis in Response to the Quorum Sensing Molecules AI-2 by : Jung Woo Yang
Download or read book Enhanced Bioethanol Production by Zymomonas Mobilis in Response to the Quorum Sensing Molecules AI-2 written by Jung Woo Yang and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The depletion of non-renewable energy resources, the environmental concern over the burning of fossil fuels, and the recent price rises and instability in the international oil markets have all combined to stimulate interest in the use of fermentation processes for the production of alternative bio-fuels. As a fuel, ethanol is mainly of interest as a petrol additive, or substrate, because ethanol-blended fuel produces a cleaner, more complete combustion that reduces greenhouse gas and toxic emissions. As a consequence of the surge in demand for biofuels, ethanol producing microorganisms, such as the bacterium Zymomonas mobilis, are of considerable interest due to their potential for industrial-scale bioethanol production. Although bioethanol has traditionally been produced in batch fermentation with the yeast Saccharomyces cerevisiae, there are advantages in using Z. mobilis as an alternative for bioethanol production. In comparison to yeast, Z. mobilis grows and ferments rapidly, without the requirement for the controlled supply of oxygen during fermentation, and has a significantly higher ethanol product rate and yield. Most importantly, it has a high tolerance for ethanol. Bacteria communicate with one another using chemical signalling molecules. In general, chemical communication involves producing, releasing, detecting, and responding to small hormone-like molecules termed autoinducers (AI). This process allows bacteria to monitor the environment for other bacteria and to alter behaviour on a population-wide scale in response to changes in the number and/or species present in a community. Currently, there are three well-defined classes of molecules that serve as the paradigms for chemical signaling in bacteria: oligopeptides, AI-1 (AHLs) and AI-2. Oligopeptide signalling is the predominant signal used by Gram-positive bacteria, and AHLs (acyl-homoserine lactones) are for species-specific communication in Gram-negative bacteria. Finally, the LuxS/AI-2 pathway is generally considered as involved in interspecies communication because the luxS gene, which is responsible for AI-2 production, is found in various bacteria. Many physiological functions in bacteria such as toxin, virulence factor and bacteriocin production, biofilm formation, bioluminescence, type III secretion, have been shown to be under the control of AI-2 quorum sensing. In Z. mobilis, in vitro synthesized and in vivo produced AI-2 treatment enhanced ethanol production by this bacterium up to a maximum of 50% in comparison with untreated control cells. This appears attributable to the overproduction of the glycolytic enzymes, enolase and pyruvate carboxylase, which are only rarely found in bacteria and the key enzymes for ethanol production. From the perspective of interspecies communication, enhanced ethanol production in Z. mobilis, under the control of the AI-2 signalling molecules, could represent a good example of a bacterium that does not produce AI-2, but responds to it. Another interesting finding is that two extracellular proteins from Z. mobilis, ZMO0994 and ZMO0134 which were originally induced by AI-2, were secreted when they were cloned, transformed and expressed in E. coli strain BL21 DE3; since it is generally accepted that nonpathogenic strains of E. coli, particularly derivatives of K12, do not secrete proteins under routine growth conditions. Presumably, these proteins possess signal sequences for secretion that could be used to provide a strategy for their use as carriers of recombinant proteins produced in E. coli K12. The merit of this system is that there would be few contaminant cytoplasmic proteins, and could possibly solve problems in protein purification, such as protease activity, protein misfolding and inclusion body formation. Finally, the discovery that the metabolic pathway leading to ethanol production is regulated by AI-2 is of considerable biotechnological importance because it will provide a basis for further engineering of strains for more efficient ethanol production. Indeed, engineering Z. mobilis by introducing the genes that encode Pfs and LuxS to produce AI-2, would be a means to stimulate increased ethanol production.
Book Synopsis Metabolic Engineering of Zymomonas Mobilis for 2,3-butanediol Production from Lignocellulosic Biomass Sugars by :
Download or read book Metabolic Engineering of Zymomonas Mobilis for 2,3-butanediol Production from Lignocellulosic Biomass Sugars written by and published by . This book was released on 2016 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: To develop pathways for advanced biofuel production, and to understand the impact of host metabolism and environmental conditions on heterologous pathway engineering for economic advanced biofuels production from biomass, we seek to redirect the carbon flow of the model ethanologen Zymomonas mobilis to produce desirable hydrocarbon intermediate 2,3-butanediol (2,3-BDO). 2,3-BDO is a bulk chemical building block, and can be upgraded in high yields to gasoline, diesel, and jet fuel. 2,3-BDO biosynthesis pathways from various bacterial species were examined, which include three genes encoding acetolactate synthase, acetolactate decarboxylase, and butanediol dehydrogenase. Bioinformatics analysis was carried out to pinpoint potential bottlenecks for high 2,3-BDO production. Different combinations of 2,3-BDO biosynthesis metabolic pathways using genes from different bacterial species have been constructed. Our results demonstrated that carbon flux can be deviated from ethanol production into 2,3-BDO biosynthesis, and all three heterologous genes are essential to efficiently redirect pyruvate from ethanol production for high 2,3-BDO production in Z. mobilis. The down-selection of best gene combinations up to now enabled Z. mobilis to reach the 2,3-BDO production of more than 10 g/L from glucose and xylose, as well as mixed C6/C5 sugar streams derived from the deacetylation and mechanical refining process. In conclusion, this study confirms the value of integrating bioinformatics analysis and systems biology data during metabolic engineering endeavors, provides guidance for value-added chemical production in Z. mobilis, and reveals the interactions between host metabolism, oxygen levels, and a heterologous 2,3-BDO biosynthesis pathway. Taken together, this work provides guidance for future metabolic engineering efforts aimed at boosting 2,3-BDO titer anaerobically.
Book Synopsis Production of Ethanol from Starch by Co-immobilized Zymomonas Mobilis -- Glucoamylase in a Fluidized-bed Reactor by :
Download or read book Production of Ethanol from Starch by Co-immobilized Zymomonas Mobilis -- Glucoamylase in a Fluidized-bed Reactor written by and published by . This book was released on 1997 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: The production of ethanol from starch was studied in a fluidized-bed reactor (FBR) using co-immobilized Zymomonas mobilis and glucoamylase. The FBR was a glass column of 2.54 cm in diameter and 120 cm in length. The Z. mobilis and glucoamylase were co-immobilized within small uniform beads (1.2 to 2.5 mm diameter) of [kappa]-carrageenan. The substrate for ethanol production was a soluble starch. Light steep water was used as the complex nutrient source. The experiments were performed at 35 C and pH range 4.0 to 5.5. The substrate concentrations ranged from 40 to 185 g/L and the feed rates from 10 to 37 mL/min. Under relaxed sterility conditions, the FBR was successfully operated for a period of 22 days, during which no contamination or structural failure of the biocatalyst beads was observed. Maximum volumetric productivity of 38 g ethanol/L-h, which was 76% of the theoretical value, was obtained. Typical ethanol volumetric productivity was in the range of 15 to 20 g/L-h. The average yield was 0.51 g ethanol/g substrate consumed, which was 90% of the theoretical yield. Very low levels of glucose were observed in the reactor, indicating that starch hydrolysis was the rate-limiting step.
Book Synopsis Bioconversion of Waste Materials to Industrial Products by : A.M. Martin
Download or read book Bioconversion of Waste Materials to Industrial Products written by A.M. Martin and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 569 pages. Available in PDF, EPUB and Kindle. Book excerpt: By covering both the general principles of bioconversion and the specific characteristics of the main groups of waste materials amenable to bioconversion methods, this new book provides the chemical, biochemical, agrochemical and process engineer with clear guidance on the use of these methods in devising a solution to the problem of industrial waste products.
Book Synopsis Prospects of Renewable Bioprocessing in Future Energy Systems by : Ali Asghar Rastegari
Download or read book Prospects of Renewable Bioprocessing in Future Energy Systems written by Ali Asghar Rastegari and published by Springer. This book was released on 2019-04-03 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses various renewable energy resources and technologies. Topics covered include recent advances in photobioreactor design; microalgal biomass harvesting, drying, and processing; and technological advances and optimised production systems as prerequisites for achieving a positive energy balance. It highlights alternative resources that can be used to replace fossil fuels, such as algal biofuels, biodiesel, bioethanol, and biohydrogen. Further, it reviews microbial technologies, discusses an immobilization method, and highlights the efficiency of enzymes as a key factor in biofuel production. In closing, the book outlines future research directions to increase oil yields in microalgae, which could create new opportunities for lipid-based biofuels, and provides an outlook on the future of global biofuel production. Given its scope, the book will appeal to all researchers and engineers working in the renewable energy sector.
Book Synopsis Microorganisms in Biorefineries by : Birgit Kamm
Download or read book Microorganisms in Biorefineries written by Birgit Kamm and published by Springer. This book was released on 2014-11-27 with total page 373 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book describes how plant biomass can be used as renewable feedstock for producing and further processing various products. Particular attention is given to microbial processes both for the digestion of biomass and the synthesis of platform chemicals, biofuels and secondary products. Topics covered include: new metabolic pathways of microbes living on green plants and in silage; using lignocellulosic hydrolysates for the production of polyhydroxyalkanoates; fungi such as Penicillium as host for the production of heterologous proteins and enzymes; bioconversion of sugar hydrolysates into lipids; production of succinic acid, lactones, lactic acid and organic lactates using different bacteria species; cellulose hydrolyzing bacteria in the production of biogas from plant biomass; and isoprenoid compounds in engineered microbes.
