Read by QxMD icon Read

Biotechnology for Biofuels

J A Méndez-Líter, J Gil-Muñoz, M Nieto-Domínguez, J Barriuso, L I de Eugenio, M J Martínez
Background: Cellulose, the most abundant biopolymer on earth, is an alternative for fossil fuels as a renewable feedstock for the production of second-generation biofuels and other chemicals. The discovery of novel, highly efficient β-glucosidases remains as one of the major bottlenecks for cellulose degradation. In this context, the ascomycete Talaromyces amestolkiae, isolated from cereal samples, has been studied as a promising source for these enzymes. Results: BGL-2 is the major β-glucosidase secreted by this fungus in the presence of cellulosic inductors...
2017: Biotechnology for Biofuels
Bruno L Mello, Anna M Alessi, Diego M Riaño-Pachón, Eduardo R deAzevedo, Francisco E G Guimarães, Melissa C Espirito Santo, Simon McQueen-Mason, Neil C Bruce, Igor Polikarpov
Background: Using globally abundant crop residues as a carbon source for energy generation and renewable chemicals production stand out as a promising solution to reduce current dependency on fossil fuels. In nature, such as in compost habitats, microbial communities efficiently degrade the available plant biomass using a diverse set of synergistic enzymes. However, deconstruction of lignocellulose remains a challenge for industry due to recalcitrant nature of the substrate and the inefficiency of the enzyme systems available, making the economic production of lignocellulosic biofuels difficult...
2017: Biotechnology for Biofuels
Aurélie Fosses, Maria Maté, Nathalie Franche, Nian Liu, Yann Denis, Romain Borne, Pascale de Philip, Henri-Pierre Fierobe, Stéphanie Perret
Background: Like a number of anaerobic and cellulolytic Gram-positive bacteria, the model microorganism Ruminiclostridium cellulolyticum produces extracellular multi-enzymatic complexes called cellulosomes, which efficiently degrade the crystalline cellulose. Action of the complexes on cellulose releases cellobiose and longer cellodextrins but to date, little is known about the transport and utilization of the produced cellodextrins in the bacterium. A better understanding of the uptake systems and fermentation of sugars derived from cellulose could have a major impact in the field of biofuels production...
2017: Biotechnology for Biofuels
Tian Zhang, Pier-Luc Tremblay
The biological reduction of CO2 driven by sunlight via photosynthesis is a crucial process for life on earth. However, the conversion efficiency of solar energy to biomass by natural photosynthesis is low. This translates in bioproduction processes relying on natural photosynthesis that are inefficient energetically. Recently, hybrid photosynthetic technologies with the potential of significantly increasing the efficiency of solar energy conversion to products have been developed. In these systems, the reduction of CO2 into biofuels or other chemicals of interest by biocatalysts is driven by solar energy captured with inorganic devices such as photovoltaic cells or photoelectrodes...
2017: Biotechnology for Biofuels
Yan Wu, Yaqiao Hao, Xuan Wei, Qi Shen, Xuanwei Ding, Liyan Wang, Hongxin Zhao, Yuan Lu
Background: Enterobacter aerogenes is a facultative anaerobe and is one of the most widely studied bacterial strains because of its ability to use a variety of substrates, to produce hydrogen at a high rate, and its high growth rate during dark fermentation. However, the rate of hydrogen production has not been optimized. In this present study, three strategies to improve hydrogen production in E. aerogenes, namely the disruption of nuoCDE, overexpression of the small RNA RyhB and of NadE to regulate global anaerobic metabolism, and the redistribution of metabolic flux...
2017: Biotechnology for Biofuels
Ruiling Gao, Zifu Li, Xiaoqin Zhou, Shikun Cheng, Lei Zheng
Background: The sustainability of microbial lipids production from traditional carbon sources, such as glucose or glycerol, is problematic given the high price of raw materials. Considerable efforts have been directed to minimize the cost and find new alternative carbon sources. Volatile fatty acids (VFAs) are especially attractive raw materials, because they can be produced from a variety of organic wastes fermentation. Therefore, the use of volatile fatty acids as carbon sources seems to be a feasible strategy for cost-effective microbial lipid production...
2017: Biotechnology for Biofuels
Rameshwar Tiwari, Puneet Kumar Singh, Surender Singh, Pawan K S Nain, Lata Nain, Pratyoosh Shukla
Background: Saccharification is the most crucial and cost-intensive process in second generation biofuel production. The deficiency of β-glucosidase in commercial enzyme leads to incomplete biomass hydrolysis. The decomposition of biomass at high temperature environments leads us to isolate thermotolerant microbes with β-glucosidase production potential. Results: A total of 11 isolates were obtained from compost and cow dung samples that were able to grow at 50 °C...
2017: Biotechnology for Biofuels
Wen Jiang, James B Qiao, Gayle J Bentley, Di Liu, Fuzhong Zhang
The intrinsic structural properties of branched long-chain fatty alcohols (BLFLs) in the range of C12 to C18 make them more suitable as diesel fuel replacements and for other industrial applications than their straight-chain counterparts. While microbial production of straight long-chain fatty alcohols has been achieved, biosynthesis of BLFLs has never been reported. In this work, we engineered four different biosynthetic pathways in Escherichia coli to produce BLFLs. We then employed a modular engineering approach to optimize the supply of α-keto acid precursors and produced either odd-chain or even-chain BLFLs with high selectivity, reaching 70 and 75% of total fatty alcohols, respectively...
2017: Biotechnology for Biofuels
Stefan Dörsam, Jana Fesseler, Olga Gorte, Thomas Hahn, Susanne Zibek, Christoph Syldatk, Katrin Ochsenreither
BACKGROUND: The organic acid producer Aspergillus oryzae and Rhizopus delemar are able to convert several alternative carbon sources to malic and fumaric acid. Thus, carbohydrate hydrolysates from lignocellulose separation are likely suitable as substrate for organic acid production with these fungi. RESULTS: Before lignocellulose hydrolysate fractions were tested as substrates, experiments with several mono- and disaccharides, possibly present in pretreated biomass, were conducted for their suitability for malic acid production with A...
2017: Biotechnology for Biofuels
Junko Yaegashi, James Kirby, Masakazu Ito, Jian Sun, Tanmoy Dutta, Mona Mirsiaghi, Eric R Sundstrom, Alberto Rodriguez, Edward Baidoo, Deepti Tanjore, Todd Pray, Kenneth Sale, Seema Singh, Jay D Keasling, Blake A Simmons, Steven W Singer, Jon K Magnuson, Adam P Arkin, Jeffrey M Skerker, John M Gladden
BACKGROUND: Economical conversion of lignocellulosic biomass into biofuels and bioproducts is central to the establishment of a robust bioeconomy. This requires a conversion host that is able to both efficiently assimilate the major lignocellulose-derived carbon sources and divert their metabolites toward specific bioproducts. RESULTS: In this study, the carotenogenic yeast Rhodosporidium toruloides was examined for its ability to convert lignocellulose into two non-native sesquiterpenes with biofuel (bisabolene) and pharmaceutical (amorphadiene) applications...
2017: Biotechnology for Biofuels
Benedikt Leis, Claudia Held, Fabian Bergkemper, Katharina Dennemarck, Robert Steinbauer, Alarich Reiter, Matthias Mechelke, Matthias Moerch, Sigrid Graubner, Wolfgang Liebl, Wolfgang H Schwarz, Vladimir V Zverlov
BACKGROUND: Clostridium thermocellum is a paradigm for efficient cellulose degradation and a promising organism for the production of second generation biofuels. It owes its high degradation rate on cellulosic substrates to the presence of supra-molecular cellulase complexes, cellulosomes, which comprise over 70 different single enzymes assembled on protein-backbone molecules of the scaffold protein CipA. RESULTS: Although all 24 single-cellulosomal cellulases were described previously, we present the first comparative catalogue of all these enzymes together with a comprehensive analysis under identical experimental conditions, including enzyme activity, binding characteristics, substrate specificity, and product analysis...
2017: Biotechnology for Biofuels
Yongguang Jiang, Peng Xiao, Qing Shao, Huan Qin, Zhangli Hu, Anping Lei, Jiangxin Wang
BACKGROUND: Microalgae have been demonstrated to be among the most promising phototrophic species for producing renewable biofuels and chemicals. Ethanol and butanol are clean energy sources with good chemical and physical properties as alternatives to gasoline. However, biosynthesis of these two biofuels has not been achieved due to low tolerance of algal cells to ethanol or butanol. RESULTS: With an eye to circumventing these problems in the future and engineering the robust alcohol-producing microalgal hosts, we investigated the metabolic responses of the model green alga Chlamydomonas reinhardtii to ethanol and butanol...
2017: Biotechnology for Biofuels
Huihui Zhou, Bingfeng Liu, Qisong Wang, Jianmin Sun, Guojun Xie, Nanqi Ren, Zhiyong Jason Ren, Defeng Xing
BACKGROUND: Microbial extracellular electron transfer (EET) is essential in driving the microbial interspecies interaction and redox reactions in bioelectrochemical systems (BESs). Magnetite (Fe3O4) and magnetic fields (MFs) were recently reported to promote microbial EET, but the mechanisms of MFs stimulation of EET and current generation in BESs are not known. This study investigates the behavior of current generation and EET in a state-of-the-art pulse electromagnetic field (PEMF)-assisted magnetic BES (PEMF-MBES), which was equipped with magnetic carbon particle (Fe3O4@N-mC)-coated electrodes...
2017: Biotechnology for Biofuels
Yang You, Bo Wu, Yi-Wei Yang, Yan-Wei Wang, Song Liu, Qi-Li Zhu, Han Qin, Fu-Rong Tan, Zhi-Yong Ruan, Ke-Dong Ma, Li-Chun Dai, Min Zhang, Guo-Quan Hu, Ming-Xiong He
BACKGROUND: Environmental issues, such as the fossil energy crisis, have resulted in increased public attention to use bioethanol as an alternative renewable energy. For ethanol production, water and nutrient consumption has become increasingly important factors being considered by the bioethanol industry as reducing the consumption of these resources would decrease the overall cost of ethanol production. Biogas slurry contains not only large amounts of wastewater, but also the nutrients required for microbial growth, e...
2017: Biotechnology for Biofuels
Chao Li, Zhongchao Gai, Kai Wang, Liping Jin
BACKGROUND: Bacillus licheniformis MW3 as a GRAS and thermophilic strain is a promising microorganism for chemical and biofuel production. However, its capacity to co-utilize glucose and xylose, the major sugars found in lignocellulosic biomass, is severely impaired by glucose-mediated carbon catabolite repression (CCR). In this study, a "dual-channel" process was implemented to engineer strain MW3 for simultaneous utilization of glucose and xylose, using l-lactic acid as a target product...
2017: Biotechnology for Biofuels
J Herlet, P Kornberger, B Roessler, J Glanz, W H Schwarz, W Liebl, V V Zverlov
BACKGROUND: Glycoside hydrolases are important for various industrial and scientific applications. Determination of their temperature as well as pH optima and range is crucial to evaluate whether an enzyme is suitable for application in a biotechnological process. These basic characteristics of enzymes are generally determined by two separate measurements. However, these lead to a two-dimensional assessment of the pH range at one temperature (and vice versa) and do not allow prediction of the relative enzymatic performance at any pH/temperature combination of interest...
2017: Biotechnology for Biofuels
Xiaojing Jia, Xiaowei Peng, Ying Liu, Yejun Han
BACKGROUND: Acetoin (3-hydroxy-2-butanone), the precursor of biofuel 2,3-butanediol, is an important bio-based platform chemical with wide applications. Fermenting the low-cost and renewable plant biomass is undoubtedly a promising strategy for acetoin production. Isothermal simultaneous saccharification and fermentation (SSF) is regarded as an efficient method for bioconversion of lignocellulosic biomass, in which the temperature optima fitting for both lignocellulose-degrading enzymes and microbial strains...
2017: Biotechnology for Biofuels
Nam Kyu Kang, Eun Kyung Kim, Young Uk Kim, Bongsoo Lee, Won-Joong Jeong, Byeong-Ryool Jeong, Yong Keun Chang
BACKGROUND: Genetic engineering of microalgae is necessary to produce economically feasible strains for biofuel production. Current efforts are focused on the manipulation of individual metabolic genes, but the outcomes are not sufficiently stable and/or efficient for large-scale production of biofuels and other materials. Transcription factors (TFs) are emerging as good alternatives for engineering of microalgae, not only to increase production of biomaterials but to enhance stress tolerance...
2017: Biotechnology for Biofuels
Bo Yang, Jin Liu, Xiaonian Ma, Bingbing Guo, Bin Liu, Tao Wu, Yue Jiang, Feng Chen
BACKGROUND: Photosynthetic microalgae are emerging as potential biomass feedstock for sustainable production of biofuels and value-added bioproducts. CO2 biomitigation through these organisms is considered as an eco-friendly and promising alternative to the existing carbon sequestration methods. Nonetheless, the inherent relatively low photosynthetic capacity of microalgae has hampered the practical use of this strategy for CO2 biomitigation applications. RESULTS: Here, we demonstrate the feasibility of improving photosynthetic capacity by the genetic manipulation of the Calvin cycle in the typical green microalga Chlorella vulgaris...
2017: Biotechnology for Biofuels
Chengcheng Li, Fengming Lin, Le Zhou, Lei Qin, Bingzhi Li, Zhihua Zhou, Mingjie Jin, Zhan Chen
BACKGROUND: The induction of cellulase production by insoluble carbon source cellulose was a common and efficient strategy, but has some drawbacks, such as difficult fermentation operation, substantial cellulase loss, long fermentation time, and high energy-consumption, resulting in high cost of cellulase production in industry. These drawbacks can be overcome if soluble carbon sources are utilized as the inducers for cellulase production. However, until now the induction efficiency of most soluble carbon sources, especially lactose and glucose, is still inferior to cellulose despite extensive efforts have been made by either optimizing the fermentation process or constructing the recombinant strains...
2017: Biotechnology for Biofuels
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"