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Wolfgang Buckel, Rudolf K Thauer
There are two types of electron bifurcation (EB), either quinone- or flavin-based (QBEB/FBEB), that involve reduction of a quinone or flavin by a two-electron transfer and two reoxidations by a high- and low-potential one-electron acceptor with a reactive semiquinone intermediate. In QBEB, the reduced low-potential acceptor (cytochrome b) is exclusively used to generate ΔμH+ . In FBEB, the "energy-rich" low-potential reduced ferredoxin or flavodoxin has dual function. It can give rise to ΔμH+ /Na+ via a ferredoxin:NAD reductase (Rnf) or ferredoxin:proton reductase (Ech) or conducts difficult reductions such as CO2 to CO...
March 21, 2018: Chemical Reviews
Sonda Guermazi-Toumi, Rakia Chouari, Abdelghani Sghir
Knowledge of archaeal population structure, function and interactions is of great interest for a deeper understanding of the anaerobic digestion step in wastewater treatment process, that represents a bottle neck in the optimization of digesters performance. Although culture-independent techniques have enabled the exploration of archaeal population in such systems, their population dynamics and interactions still require further investigation. In the present study, 2646 almost full archaeal 16S rRNA gene sequences retrieved from 22 anaerobic digesters located worldwide were analyzed and classified into 83 Operational Taxonomic Units (OTUs) for Euryarchaeotes and 2 OTUs for Crenarchaeotes...
March 21, 2018: Environmental Technology
Valéria Nagy, Anna Podmaniczki, André Vidal-Meireles, Roland Tengölics, László Kovács, Gábor Rákhely, Alberto Scoma, Szilvia Z Tóth
Background: Photobiological H2 production has the potential of becoming a carbon-free renewable energy source, because upon the combustion of H2 , only water is produced. The [Fe-Fe]-type hydrogenases of green algae are highly active, although extremely O2 -sensitive. Sulphur deprivation is a common way to induce H2 production, which, however, relies substantially on organic substrates and imposes a severe stress effect resulting in the degradation of the photosynthetic apparatus. Results: We report on the establishment of an alternative H2 production method by green algae that is based on a short anaerobic induction, keeping the Calvin-Benson-Bassham cycle inactive by substrate limitation and preserving hydrogenase activity by applying a simple catalyst to remove the evolved O2 ...
2018: Biotechnology for Biofuels
Ouwei Wang, Ryan A Melnyk, Misha G Mehta-Kolte, Matthew D Youngblut, Hans K Carlson, John D Coates
Most dissimilatory perchlorate reducing bacteria (DPRB) are also capable of respiratory nitrate reduction, and preferentially utilize nitrate over perchlorate as a terminal electron acceptor. The similar domain architectures and phylogenetic relatedness of the nitrate and perchlorate respiratory complexes suggests a common evolutionary history and a potential for functionally redundant electron carriers. In this study, we identify key genetic redundancies in the electron transfer pathways from the quinone pool(s) to the terminal nitrate and perchlorate reductases in Azospira suillum PS (hereafter referred to as PS)...
2018: Frontiers in Microbiology
Zheng Lu, Ramakrishnan Sethu, James A Imlay
It has been unclear whether superoxide and/or hydrogen peroxide play important roles in the phenomenon of obligate anaerobiosis. This question was explored using Bacteroides thetaiotaomicron , a major fermentative bacterium in the human gastrointestinal tract. Aeration inactivated two enzyme families-[4Fe-4S] dehydratases and nonredox mononuclear iron enzymes-whose homologs, in contrast, remain active in aerobic Escherichia coli Inactivation-rate measurements of one such enzyme, B. thetaiotaomicron fumarase, showed that it is no more intrinsically sensitive to oxidants than is an E...
March 20, 2018: Proceedings of the National Academy of Sciences of the United States of America
K E Boiten, H Jean-Pierre, A C M Veloo
Within the European Network for the Rapid Identification of Anaerobes (ENRIA) project eight clinical isolates of Fenollaria massiliensis were encountered. In this study a more extensive description of this species is given and the MALDI-TOF MS database is optimized for its identification. F. massiliensis is an anaerobic Gram positive rod with the tendency to decolorize quickly. It is mostly encountered in clinical samples from the groin region. Less common and non-valid species are not represented in the MALDI-TOF MS database...
March 17, 2018: Anaerobe
Shuangshuang Ma, Chen Fang, Xiaoxi Sun, Lujia Han, Xueqin He, Guangqun Huang
Bacteria play an important role in organic matter degradation and maturity during aerobic composting. This study analyzed composting with or without a membrane cover in laboratory-scale aerobic composting reactor systems. 16S rRNA gene analysis was used to study the bacterial community succession during composting. The richness of the bacterial community decreased and the diversity increased after covering with a semi-permeable membrane and applying a slight positive pressure. Principal components analysis based on operational taxonomic units could distinguish the main composting phases...
March 14, 2018: Bioresource Technology
Ahmed Farghaly, Sophie Le Roux, Pascal Peu, Patrick Dabert, Ahmed Tawfik
The aim of this study is to highlight the robustness and potentials of the anaerobic baffled reactor (ABR) configuration on keeping the microbial richness and diversity after starvation period of 7 days. The module at steady state operating conditions provided an average volumetric hydrogen production (VHP) of 0.2±0.08 and 0.423±0.5 l/d in the 1st and last compartment (C4). The VHP was gradually decreased from 0.2 to 0.003 l/d and from 0.423 to 0.1 l/d in compartments (C1 and C4) respectively during feed less period...
March 20, 2018: Environmental Technology
Namita Maharjan, Naoki Nomoto, Tadashi Tagawa, Tsutomu Okubo, Shigeki Uemura, Nadeem Khalil, Masashi Hatamoto, Takashi Yamaguchi, Hideki Harada
This paper assesses the technical and economic sustainability of a combined system of an upflow anaerobic sludge blanket (UASB)- down-flow hanging sponge (DHS) for sewage treatment. Additionally, this study compares UASB-DHS with current technologies in India like trickling filters (TF), sequencing batch reactor (SBR), moving bed biofilm reactor (MBBR), and other combinations of UASB with post-treatment systems such as final polishing ponds (FPU) and extended aeration sludge process (EASP). The sustainability of the sewage treatment plants (STPs) was evaluated using a composite indicator, which incorporated environmental, societal and economic dimensions...
March 20, 2018: Environmental Technology
Jin-Xuan Fan, Zi-Hao Li, Xin-Hua Liu, Diwei Zheng, Ying Chen, Xian-Zheng Zhang
Oral drug administration is widely adopted for diverse drugs, and enjoys the convenience of use and capbility to reach different parts of the body via the bloodstream. However, it is generally not feasible for biomacromolecular anti-tumor drugs such as protein and nucleic acids due to the the limited absorption through gastrointestinal tract (GIT) and the poor tumor targeting. Here, we report a non-invasive thermally-sensitive programmable therapetic system using bacteria E. coli MG1655 as an vehicle for tumor treatments via oral administration...
March 20, 2018: Nano Letters
Jarred G Gillett, Glen A Lichtwark, Roslyn N Boyd, Lee A Barber
PURPOSE: To investigate the efficacy of a 12-week combined functional anaerobic and strength training program on neuromuscular properties and functional capacity in young adults with spastic-type CP. METHODS: 17 young adults (21±4 years, 9 males, GMFCS I=11, II=6) were randomized to 12 weeks, 3 sessions per week, of high intensity functional anaerobic and progressive resistance training of the lower limbs (n=8), or a waitlist control group (n=9). Pre- and post-training plantar flexor and tibialis anterior muscle volumes and composition, passive and active plantar flexor muscle properties, and functional capacity outcomes were assessed...
March 20, 2018: Medicine and Science in Sports and Exercise
Yuli Wei, Jiasong Fang, Yunping Xu, Weiqiang Zhao, Junwei Cao
A novel heterotrophic, Gram-stain-positive, facultatively anaerobic and rod-shaped bacterium, designated strain NBT06-6T , was isolated from the deep seawater in the New Britain Trench and characterized phylogenetically and phenotypically. Optimal bacterial growth occurred at 35 °C (range 22-41 °C), at pH 6 (4-8) and with 4 % (w/v) NaCl (0-10 %). The strain grew at hydrostatic pressures of 0.1-100 MPa (optimum, 0.1 MPa) at 35 °C. Phylogenetic analysis of the 16S rRNA gene sequences indicated that strain NBT06-6T belonged to the genus Corynebacterium, with the highest sequence similarity (97...
March 20, 2018: International Journal of Systematic and Evolutionary Microbiology
Tomohiro Gonjo, Carla McCabe, Ana Sousa, João Ribeiro, Ricardo J Fernandes, João Paulo Vilas-Boas, Ross Sanders
PURPOSE: The purpose of this study was to determine kinematic and energetic differences between front crawl and backstroke performed at the same aerobic speeds. METHODS: Ten male competitive swimmers performed front crawl and backstroke at a pre-determined sub-anaerobic threshold speed to assess energy cost (through oxygen uptake measurement) and kinematics (using three-dimensional videography to determine stroke frequency and length, intra-cycle velocity fluctuation, three-dimensional wrist and ankle speeds, and vertical and lateral ankle range of motion)...
March 19, 2018: European Journal of Applied Physiology
Victoria Pons, Joan Riera, Xavier Capó, Miquel Martorell, Antoni Sureda, Josep A Tur, Franchek Drobnic, Antoni Pons
Background: Caloric restriction induces mitochondrial biogenesis and improves physical fitness in rodents. We aimed to provide evidence of how caloric restriction affects the body composition and physical performance of trained athletes and to evaluate the possible impact of an every-other-day feeding diet on nutritional deficiencies of micronutrients and essential fatty acids. Methods: The study was performed with 12 healthy male athletes by carrying out a 33% caloric restriction with respect to their usual diet...
2018: Journal of the International Society of Sports Nutrition
Stephen E Beaton, Rhiannon M Evans, Alexander J Finney, Ciaran M Lamont, Fraser A Armstrong, Frank Sargent, Stephen B Carr
Under anaerobic conditions Escherichia coli is able to metabolize molecular hydrogen via the action of several [NiFe]-hydrogenase enzymes. Hydrogenase-2, which is typically present in cells at low levels during anaerobic respiration, is a periplasmic-facing membrane-bound complex that functions as a proton pump to convert energy from H2 oxidation into a proton gradient; consequently, its structure is of great interest. Empirically, the complex consists of a tightly-bound core catalytic module, comprising large (HybC) and small (HybO) subunits, which is attached to an Fe-S protein (HybA) and an integral membrane protein, HybB...
March 19, 2018: Biochemical Journal
(no author information available yet)
No abstract text is available yet for this article.
April 2018: Thorax
Paul P Lin, Alec J Jaeger, Tung-Yun Wu, Sharon C Xu, Abraxa S Lee, Fanke Gao, Po-Wei Chen, James C Liao
The Embden-Meyerhoff-Parnas (EMP) pathway, commonly known as glycolysis, represents the fundamental biochemical infrastructure for sugar catabolism in almost all organisms, as it provides key components for biosynthesis, energy metabolism, and global regulation. EMP-based metabolism synthesizes three-carbon (C3) metabolites before two-carbon (C2) metabolites and must emit one CO2 in the synthesis of the C2 building block, acetyl-CoA, a precursor for many industrially important products. Using rational design, genome editing, and evolution, here we replaced the native glycolytic pathways in Escherichia coli with the previously designed nonoxidative glycolysis (NOG), which bypasses initial C3 formation and directly generates stoichiometric amounts of C2 metabolites...
March 19, 2018: Proceedings of the National Academy of Sciences of the United States of America
Iain G Thomson, Matthew P Wallen, Adrian Hall, Rebekah Ferris, David C Gotley, Andrew P Barbour, Andrew Lee, Janine Thomas, Bernard M Smithers
Neoadjuvant therapy (NAT) for oesophageal cancer may reduce cardiopulmonary function, assessed by cardiopulmonary exercise testing (CPEX). Impaired cardiopulmonary function is associated with mortality following esophagectomy. We sought to assess the impact of NAT on cardiopulmonary function using CPEX and assessing the clinical relevance of any change in particular if changes were associated with post-operative morbidity. This was a prospective, cohort study of 40 patients in whom CPEX was performed before and after NAT...
March 16, 2018: International Journal of Surgery
Peng Wei, Katja K Dove, Claire Bensard, John C Schell, Jared Rutter
Compared to their differentiated progeny, stem cells are often characterized by distinct metabolic landscapes that emphasize anaerobic glycolysis and a lower fraction of mitochondrial carbohydrate oxidation. Until recently, the metabolic program of stem cells had been thought to be a byproduct of the environment, rather than an intrinsic feature determined by the cell itself. However, new studies highlight the impact of metabolic behavior on the maintenance and function of intestinal stem cells and hair follicle stem cells...
March 16, 2018: Trends in Cell Biology
Buchun Si, Jiaming Li, Zhangbing Zhu, Mengmeng Shen, Jianwen Lu, Na Duan, Yuanhui Zhang, Qiang Liao, Yun Huang, Zhidan Liu
One critical challenge of hydrothermal liquefaction (HTL) is its complex aqueous product, which has a high concentration of organic pollutants (up to 100gCOD/L) and diverse fermentation inhibitors, such as furfural, phenolics and N-heterocyclic compounds. Here we report continuous anaerobic digestion of HTL wastewater via an up-flow anaerobic sludge bed reactor (UASB) and packed bed reactor (PBR). Specifically, we investigated the transformation of fermentation inhibitors and microbial response. GC-MS identified the complete degradation of furfural and 5-hydroxymethylfurfural (5-HMF), and partial degradation (54...
March 1, 2018: Science of the Total Environment
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