scholarly journals Identification and Deletion of The Genes Responsible for Hydrogen Production in Thermoanaerobacter Ethanolicus JW200

2021 ◽  
Author(s):  
Xiongjun Shao ◽  
Christopher D. Herring ◽  
Yuanxin Zhang ◽  
Gang Zhang ◽  
Liang Tian ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Methyl Viologen ◽  
Pyrococcus Furiosus ◽  
Gene Clusters ◽  
Product Distribution ◽  
Hydrogenase Activity ◽  
High Hydrogen ◽  
Thermoanaerobacter Ethanolicus ◽  
Cell Extracts ◽  
High Degree

Abstract Background Thermoanaerobacter ethanolicus produces a considerable amount of ethanol from a range of carbohydrates and is an attractive candidate for applications in bioconversion processes. Due to the coupling of hydrogenase activity with fermentation product distribution, understanding hydrogen production of T. ethanolicus, particularly the genes responsible, is valuable for metabolic engineering of the species. Results Utilizing the hydrogenases reported in Thermoanaerobacterium saccharolyticum and Pyrococcus furiosus as templates, BLAST search identified five hydrogenase gene clusters, including two membrane-bound [NiFe] hydrogenases ech and mbh, two cytoplasmic [FeFe] hydrogenases hyd and hydII, and one cytoplasmic [NiFe] hydrogenase shi. The combined deletion of ech, mbh, shi and hydG resulted in a strain that did not produce hydrogen and showed no methyl viologen hydrogenase activity in cell extracts. Strains with deletions of all the hydrogenases except one showed normal hydrogen production. Methyl viologen hydrogenase activity was greatly reduced in all combined deletion strains except the strain with an intact hydG gene. Conclusion High hydrogen production and hydrogenase activities have been observed for T. ethanolicus. Five hydrogenases have been identified. Hydrogen production was eliminated by deleting genes required for all five hydrogenases. Each individual hydrogenase was verified to be capable of producing hydrogen during fermentation, indicating a high degree of redundancy and flexibility in the hydrogenase systems of T. ethanolicus. A large portion of hydrogenase activity is encoded by the [Fe-Fe] hydrogenases.

Studies on some characteristics of hydrogen production by cell-free extracts of rumen anaerobic bacteria

1977 ◽  
Vol 23 (3) ◽  
pp. 346-353 ◽  
Author(s):  
A. E. Joyner ◽  
W. T. Winter ◽  
D. M. Godbout
Keyword(s):  
Hydrogen Production ◽  
Methyl Viologen ◽  
Anaerobic Bacteria ◽  
Deae Cellulose ◽  
Clostridium Pasteurianum ◽  
Hydrogenase Activity ◽  
Rumen Microorganisms ◽  
Butyrivibrio Fibrisolvens ◽  
E Coli ◽  
Eubacterium Limosum

Hydrogen production was studied in the following rumen anaerobes: Bacteroides clostridiiformis, Butyrivibrio fibrisolvens, Eubacterium limosum, Fasobacterium necrophormn, Megasphaera elsdenii, Ruminococcus albus, and Ruminococcus flavefaciens. Clostridium pasteurianum and Escherichia coli were included for comparative purposes. Hydrogen production from dithionite, dithionite-reduced methyl viologen, pyruvate, and formate was determined. All species tested produced hydrogen from dithionite-reduced methyl viologen, but only C. pasteurianum, B. clostridiiformis, E. limosum, and M. elsdenii produced hydrogen from dithionite. All species except E. coli produced hydrogen from pyruvate, but activity was low or absent in extracts of E. limosum, F. necrophorum, R. albus, and R. flavefaciens unless methyl viologen was added. Hydrogen was produced from formate only by E. coli, B. clostridiiformis, E. limosum, F. necrophorum, and R. flavefaciens. Extracts were subjected to ultracentrifugation in an effort to determine the solubility of hydrogenase. The hydrogenase of all species except E. coli appeared to be soluble, although variable amounts of hydrogenase activity were detected in the pellet. Treatment of extracts of the rumen microbial species with DEAE-cellulose resulted in loss of hydrogen production from pyruvate. Activity was restored by the addition of methyl viologen. It is concluded that hydrogen production in these rumen microorganisms is similar to that in the saccharolytic clostridia.

scholarly journals Characterization of Hydrogenase and Reductive Dehalogenase Activities of Dehalococcoides ethenogenes Strain 195

2005 ◽  
Vol 71 (3) ◽  
pp. 1664-1667 ◽  
Author(s):  
Ivonne Nijenhuis ◽  
Stephen H. Zinder
Keyword(s):  
Reductive Dechlorination ◽  
Methyl Viologen ◽  
Hydrogenase Activity ◽  
Atpase Inhibitor ◽  
Benzyl Viologen ◽  
Reductive Dehalogenase ◽  
Cell Extracts ◽  
Dehalococcoides Ethenogenes ◽  
In Cells

ABSTRACT Dehalococcoides ethenogenes strain 195 reductively dechlorinates tetrachloroethene (PCE) and trichloroethene (TCE) to vinyl chloride and ethene using H2 as an electron donor. PCE- and TCE-reductive dehalogenase (RD) activities were mainly membrane associated, whereas only about 20% of the hydrogenase activity was membrane associated. Experiments with methyl viologen (MV) were consistent with a periplasmic location for the RDs or a component feeding electrons to them. The protonophore uncoupler tetrachlorosalicylanilide did not inhibit reductive dechlorination in cells incubated with H2 and PCE and partially restored activity in cells incubated with the ATPase inhibitor N,N′-dicyclohexylcarbodiimide. Benzyl viologen or diquat (E o′ ≈ −360 mV) supported reductive dechlorination of PCE or TCE at rates comparable to MV (−450 mV) in cell extracts.

scholarly journals Reinvestigation of the Steady-State Kinetics and Physiological Function of the Soluble NiFe-Hydrogenase I of Pyrococcus furiosus

2007 ◽  
Vol 190 (5) ◽  
pp. 1584-1587 ◽  
Author(s):  
Daan J. van Haaster ◽  
Pedro J. Silva ◽  
Peter-Leon Hagedoorn ◽  
Jaap A. Jongejan ◽  
Wilfred R. Hagen
Keyword(s):  
Steady State ◽  
Hydrogen Production ◽  
Physiological Function ◽  
Pyrococcus Furiosus ◽  
High Hydrogen ◽  
Hydrogen Consumption ◽  
Steady State Kinetics ◽  
Production Activity ◽  
Membrane Bound ◽  
Consumption Activity

ABSTRACT Pyrococcus furiosus has two types of NiFe-hydrogenases: a heterotetrameric soluble hydrogenase and a multimeric transmembrane hydrogenase. Originally, the soluble hydrogenase was proposed to be a new type of H2 evolution hydrogenase, because, in contrast to all of the then known NiFe-hydrogenases, the hydrogen production activity at 80°C was found to be higher than the hydrogen consumption activity and CO inhibition appeared to be absent. NADPH was proposed to be the electron donor. Later, it was found that the membrane-bound hydrogenase exhibits very high hydrogen production activity sufficient to explain cellular H2 production levels, and this seems to eliminate the need for a soluble hydrogen production activity and therefore leave the soluble hydrogenase without a physiological function. Therefore, the steady-state kinetics of the soluble hydrogenase were reinvestigated. In contrast to previous reports, a low K m for H2 (∼20 μM) was found, which suggests a relatively high affinity for hydrogen. Also, the hydrogen consumption activity was 1 order of magnitude higher than the hydrogen production activity, and CO inhibition was significant (50% inhibition with 20 μM dissolved CO). Since the K m for NADP+ is ∼37 μM, we concluded that the soluble hydrogenase from P. furiosus is likely to function in the regeneration of NADPH and thus reuses the hydrogen produced by the membrane-bound hydrogenase in proton respiration.

scholarly journals Proteogenomic Insights into the Physiology of Marine, Sulfate-Reducing, Filamentous Desulfonema limicola and Desulfonema magnum

2021 ◽  
Vol 31 (1) ◽  
pp. 36-56
Author(s):  
Vanessa Schnaars ◽  
Lars Wöhlbrand ◽  
Sabine Scheve ◽  
Christina Hinrichs ◽  
Richard Reinhardt ◽  
...  
Keyword(s):  
Energy Metabolism ◽  
Gene Clusters ◽  
Transport Systems ◽  
Natural Habitats ◽  
Sulfate Reducing ◽  
Type Iv ◽  
Aromatic Compound Degradation ◽  
High Degree ◽  
Reducing Bacteria ◽  
Gliding Movement

The genus Desulfonema belongs to the deltaproteobacterial family Desulfobacteraceae and comprises marine, sulfate-reducing bacteria that form filaments and move by gliding. This study reports on the complete, manually annotated genomes of Dn. limicola 5ac10T (6.91 Mbp; 6,207 CDS) and Dn. magnum 4be13T (8.03 Mbp; 9,970 CDS), integrated with substrate-specific proteome profiles (8 vs. 11). The richness in mobile genetic elements is shared with other Desulfobacteraceae members, corroborating horizontal gene transfer as major driver in shaping the genomes of this family. The catabolic networks of Dn. limicola and Dn. magnum have the following general characteristics: 98 versus 145 genes assigned (having genomic shares of 1.7 vs. 2.2%), 92.5 versus 89.7% proteomic coverage, and scattered gene clusters for substrate degradation and energy metabolism. The Dn. magnum typifying capacity for aromatic compound degradation (e.g., p-cresol, 3-phenylpropionate) requires 48 genes organized in operon-like structures (87.7% proteomic coverage; no homologs in Dn. limicola). The protein complements for aliphatic compound degradation, central pathways, and energy metabolism are highly similar between both genomes and were identified to a large extent (69–96%). The differential protein profiles revealed a high degree of substrate-specificity for peripheral reaction sequences (forming central intermediates), agreeing with the high number of sensory/regulatory proteins predicted for both strains. By contrast, central pathways and modules of the energy metabolism were constitutively formed under the tested substrate conditions. In accord with their natural habitats that are subject to fluctuating changes of physicochemical parameters, both Desulfonema strains are well equipped to cope with various stress conditions. Next to superoxide dismutase and catalase also desulfoferredoxin and rubredoxin oxidoreductase are formed to counter exposure to molecular oxygen. A variety of proteases and chaperones were detected that function in maintaining cellular homeostasis upon heat or cold shock. Furthermore, glycine betaine/proline betaine transport systems can respond to hyperosmotic stress. Gliding movement probably relies on twitching motility via type-IV pili or adventurous motility. Taken together, this proteogenomic study demonstrates the adaptability of Dn. limicola and Dn. magnum to its dynamic habitats by means of flexible catabolism and extensive stress response capacities.

A newly isolated Rhodobacter sphaeroides HY01 with high hydrogen production performance

2014 ◽  
Vol 39 (19) ◽  
pp. 10051-10060 ◽  
Author(s):  
Honghui Yang ◽  
Jing Zhang ◽  
Xueqing Wang ◽  
Feng Jiangtao ◽  
Wei Yan ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Rhodobacter Sphaeroides ◽  
Production Performance ◽  
High Hydrogen

Balancing electron transfer rate and driving force for efficient photocatalytic hydrogen production in CdSe/CdS nanorod–[NiFe] hydrogenase assemblies

2017 ◽  
Vol 10 (10) ◽  
pp. 2245-2255 ◽  
Author(s):  
Bryant Chica ◽  
Chang-Hao Wu ◽  
Yuhgene Liu ◽  
Michael W. W. Adams ◽  
Tianquan Lian ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Hydrogen Production ◽  
Driving Force ◽  
Transfer Rate ◽  
Pyrococcus Furiosus ◽  
Electron Transfer Rate ◽  
Photocatalytic Hydrogen Production ◽  
Photocatalytic System

We describe a hybrid photocatalytic system for hydrogen production consisting of nanocrystalline CdSe/CdS dot-in-rod (DIR) structures coupled to [NiFe] soluble hydrogenase I (SHI) fromPyrococcus furiosus.

Remarkable intron and exon sequence conservation in human and mouse homeobox Hox 1.3 genes

1989 ◽  
Vol 9 (5) ◽  
pp. 2273-2278
Author(s):  
E Tournier-Lasserve ◽  
W F Odenwald ◽  
J Garbern ◽  
J Trojanowski ◽  
R A Lazzarini
Keyword(s):  
Sequence Similarity ◽  
Gene Clusters ◽  
Binding Studies ◽  
Base Pairs ◽  
Cis Element ◽  
Multiple Transcripts ◽  
Exon Sequence ◽  
Dna Binding Studies ◽  
High Degree ◽  
Sequence Similarities

A high degree of conservation exists between the Hox 1.3 homeobox genes of mice and humans. The two genes occupy the same relative positions in their respective Hox 1 gene clusters, they show extensive sequence similarities in their coding and noncoding portions, and both are transcribed into multiple transcripts of similar sizes. The predicted human Hox 1.3 protein differs from its murine counterpart in only 7 of 270 amino acids. The sequence similarity in the 250 base pairs upstream of the initiation codon is 98%, the similarity between the two introns, both 960 base pairs long, is 72%, and the similarity in the 3' noncoding region from termination codon to polyadenylation signal is 90%. Both mouse and human Hox 1.3 introns contain a sequence with homology to a mating-type-controlled cis element of the yeast Ty1 transposon. DNA-binding studies with a recombinant mouse Hox 1.3 protein identified two binding sites in the intron, both of which were within the region of shared homology with this Ty1 cis element.

Hydrogen Evolution Catalyzed by Hydrogenase in Cultures of Cyanobacteria

1981 ◽  
Vol 36 (1-2) ◽  
pp. 87-92 ◽  
Author(s):  
Patrick C. Hallenbeck ◽  
Leon V. Kochian ◽  
John R. Benemann
Keyword(s):  
Hydrogen Production ◽  
Hydrogen Evolution ◽  
High Frequency ◽  
Nitrogenase Activity ◽  
Inhibitory Effect ◽  
Hydrogenase Activity ◽  
Oxygen Inhibition ◽  
Oxygen Sensitive

Abstract Cultures of Anabaena cylindrica, grown on media containing 5 mᴍ NH4Cl (which represses heterocyst formation), evolved hydrogen after a period of dark incubation under an argon atmosphere. This hydrogen production was not due to nitrogenase activity, which was nearly undetectable, but was due to a hydrogenase. Cultures grown on media with tungsten substituted for molybdenum had a high frequency of heterocysts (15%) and inactive nitrogenase after nitrogen starvation. The hydrogenase activity of these cultures was three-fold greater than the activity of non-heterocystous cultures. The effects of oxygen inhibition on hydrogen evolution by hetero-cystous cultures suggest that two pools of hydrogenase activity exist - an oxygen sensitive hydrogen evolution in vegetative cells and a relatively oxygen-resistent hydrogen evolution in heterocysts. In either case, inhibition by oxygen was reversible. Light had an inhibitory effect on net hydrogen evolution. Hydrogen production in vitro was much higher than in vivo, indicating that in vivo hydrogenase activity is limited by endogenous reductant supply.

scholarly journals Molecular and Genetic Analyses of the Putative Proteus O Antigen Gene Locus

2010 ◽  
Vol 76 (16) ◽  
pp. 5471-5478 ◽  
Author(s):  
Quan Wang ◽  
Agnieszka Torzewska ◽  
Xiaojuan Ruan ◽  
Xiaoting Wang ◽  
Antoni Rozalski ◽  
...  
Keyword(s):  
Fragment Length Polymorphism ◽  
Gene Clusters ◽  
Molecular Classification ◽  
Opportunistic Pathogens ◽  
Antigen Gene ◽  
O Antigen ◽  
Tract Infections ◽  
High Degree

ABSTRACT Proteus species are well-characterized opportunistic pathogens primarily associated with urinary tract infections (UTI) of humans. The Proteus O antigen is one of the most variable constituents of the cell surface, and O antigen heterogeneity is used for serological classification of Proteus isolates. Even though most Proteus O antigen structures have been identified, the O antigen locus has not been well characterized. In this study, we identified the putative Proteus O antigen locus and demonstrated this region's high degree of heterogeneity by comparing sequences of 40 Proteus isolates using PCR-restriction fragment length polymorphism (RFLP). This analysis identified five putative Proteus O antigen gene clusters, and the probable functions of these O antigen-related genes were proposed, based on their similarity to genes in the available databases. Finally, Proteus-specific genes from these five serogroups were identified by screening 79 strains belonging to the 68 Proteus O antigen serogroups. To our knowledge, this is the first molecular characterization of the putative Proteus O antigen locus, and we describe a novel molecular classification method for the identification of different Proteus serogroups.

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