scholarly journals Discovery and Biosynthesis of Clostyrylpyrones from the Obligate Anaerobe Clostridium roseum

2020 ◽  
Vol 22 (21) ◽  
pp. 8204-8209 ◽  
Author(s):  
Jeffrey S. Li ◽  
Yongle Du ◽  
Di Gu ◽  
Wenlong Cai ◽  
Allison Green ◽  
...  
Keyword(s):  
Obligate Anaerobe

Menaquinone (MK-6) in the sulfate-reducing obligate anaerobe, Desulfovibrio

1970 ◽  
Vol 197 (1) ◽  
pp. 87-89 ◽  
Author(s):  
J. Maroc ◽  
R. Azerad ◽  
M.D. Kamen ◽  
J. Le Gall
Keyword(s):  
Obligate Anaerobe ◽  
Sulfate Reducing

Changes in the gut microbiota during and after commercial helium–oxygen saturation diving in China

2019 ◽  
Vol 76 (11) ◽  
pp. 801-807
Author(s):  
Yuan Yuan ◽  
Guosheng Zhao ◽  
Hongwei Ji ◽  
Bin Peng ◽  
Zhiguo Huang ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Oxygen Saturation ◽  
Amplicon Sequencing ◽  
Obligate Anaerobe ◽  
Sequencing Platform ◽  
Β Diversity ◽  
Faecal Samples ◽  
Increasing Trend ◽  
Hyperbaric Environment ◽  
Illumina Sequencing Platform

ObjectivesThe influence of commercial helium–oxygen saturation diving on divers’ gut microbiotas was assessed to provide dietary suggestion.MethodsFaecal samples of 47 divers working offshore were collected before (T1), during (T2) and after (T3) saturation diving. Their living and excursion depths were 55–134 metres underwater with a saturation duration of 12–31 days and PaO2 of 38–65 kPa. The faecal samples were examined through 16S ribosomal DNA amplicon sequencing based on the Illumina sequencing platform to analyse changes in the bacteria composition in the divers’ guts.ResultsAlthough the α and β diversity of the gut microbiota did not change significantly, we found that living in a hyperbaric environment of helium–oxygen saturation decreased the abundance of the genus Bifidobacterium, an obligate anaerobe, from 2.43%±3.83% at T1 to 0.79%±1.23% at T2 and 0.59%±0.79% at T3. Additionally, the abundance of some short-chain fatty acid (SCFA)-producing bacteria, such as Fusicatenibacter, Faecalibacterium, rectale group and Anaerostipes, showed a decreased trend in the order of before, during and after diving. On the contrary, the abundance of species, such as Lactococcus garvieae, Actinomyces odontolyticus, Peptoclostridium difficile, Butyricimonas virosa, Streptococcus mutans, Porphyromonas asaccharolytica and A. graevenitzii, showed an increasing trend, but most of them were pathogens.ConclusionsOccupational exposure to high pressure in a helium–oxygen saturation environment decreased the abundance of Bifidobacterium and some SCFA-producing bacteria, and increased the risk of pathogenic bacterial infection. Supplementation of the diver diet with probiotics or prebiotics during saturation diving might prevent these undesirable changes.

scholarly journals O2 and Reactive Oxygen Species Detoxification Complex, Composed of O2-Responsive NADH:Rubredoxin Oxidoreductase-Flavoprotein A2-Desulfoferrodoxin Operon Enzymes, Rubperoxin, and Rubredoxin, in Clostridium acetobutylicum

2009 ◽  
Vol 75 (4) ◽  
pp. 1021-1029 ◽  
Author(s):  
Shinji Kawasaki ◽  
Yu Sakai ◽  
Tohru Takahashi ◽  
Ippei Suzuki ◽  
Youichi Niimura
Keyword(s):  
Clostridium Acetobutylicum ◽  
Nadh Oxidase ◽  
Culture Conditions ◽  
Superoxide Reductase ◽  
Obligate Anaerobe ◽  
Gene Encoding ◽  
High Affinity ◽  
Nadh Peroxidase ◽  
Genes Encoding ◽  
Nadh Oxidase Activity

ABSTRACT Clostridium acetobutylicum, an obligate anaerobe, grows normally under continuous-O2-flow culture conditions, where the cells consume O2 proficiently. An O2-responsive NADH:rubredoxin oxidoreductase operon composed of three genes (nror, fprA2, and dsr), encoding NROR, functionally uncharacterized flavoprotein A2 (FprA2), and the predicted superoxide reductase desulfoferrodoxin (Dsr), has been proposed to participate in defense against O2 stress. To functionally characterize these proteins, native NROR from C. acetobutylicum, recombinant NROR (rNROR), FprA2, Dsr, and rubredoxin (Rd) expressed in Escherichia coli were purified. Purified native NROR and rNROR both exhibited weak H2O2-forming NADH oxidase activity that was slightly activated by Rd. A mixture of NROR, Rd, and FprA2 functions as an efficient H2O-forming NADH oxidase with a high affinity for O2 (the Km for O2 is 2.9 � 0.4 μM). A mixture of NROR, Rd, and Dsr functions as an NADH-dependent O2 − reductase. A mixture of NROR, Rd, and rubperoxin (Rpr, a rubrerythrin homologue) functions as an inefficient H2O-forming NADH oxidase but an efficient NADH peroxidase with a low affinity for O2 and a high affinity for H2O2 (the Km s for O2 and H2O2 are 303 � 39 μM and ≤1 μM, respectively). A gene encoding Rd is dicistronically transcribed with a gene encoding a glutaredoxin (Gd) homologue, and the expression levels of the genes encoding Gd and Rd were highly upregulated upon exposure to O2. Therefore, nror operon enzymes, together with Rpr, efficiently function to scavenge O2, O2 −, and H2O2 by using an O2-responsive rubredoxin as a common electron carrier protein.

Clostridioides difficile Spore Formation and Germination: New Insights and Opportunities for Intervention

2020 ◽  
Vol 74 (1) ◽  
pp. 545-566
Author(s):  
Aimee Shen
Keyword(s):  
Molecular Mechanisms ◽  
Bacterial Pathogen ◽  
Disease Recurrence ◽  
Spore Formation ◽  
Obligate Anaerobe ◽  
Infection Cycle ◽  
Clostridioides Difficile ◽  
Distinct Mechanism ◽  
Assembly Pathway ◽  
Bacillus Spp

Spore formation and germination are essential for the bacterial pathogen Clostridioides difficile to transmit infection. Despite the importance of these developmental processes to the infection cycle of C. difficile, the molecular mechanisms underlying how this obligate anaerobe forms infectious spores and how these spores germinate to initiate infection were largely unknown until recently. Work in the last decade has revealed that C. difficile uses a distinct mechanism for sensing and transducing germinant signals relative to previously characterized spore formers. The C. difficile spore assembly pathway also exhibits notable differences relative to Bacillus spp., where spore formation has been more extensively studied. For both these processes, factors that are conserved only in C. difficile or the related Peptostreptococcaceae family are employed, and even highly conserved spore proteins can have differential functions or requirements in C. difficile compared to other spore formers. This review summarizes our current understanding of the mechanisms controlling C. difficile spore formation and germination and describes strategies for inhibiting these processes to prevent C. difficile infection and disease recurrence.

scholarly journals Oxygen-dependent growth of the obligate anaerobe Desulfovibrio vulgaris Hildenborough.

1997 ◽  
Vol 179 (17) ◽  
pp. 5598-5601 ◽  
Author(s):  
M S Johnson ◽  
I B Zhulin ◽  
M E Gapuzan ◽  
B L Taylor
Keyword(s):  
Desulfovibrio Vulgaris ◽  
Obligate Anaerobe ◽  
Desulfovibrio Vulgaris Hildenborough ◽  
Dependent Growth

scholarly journals Draft Genome Sequence ofLevilinea saccharolyticaKIBI-1, a Member of theChloroflexiClassAnaerolineae

2015 ◽  
Vol 3 (6) ◽  
Author(s):  
James Hemp ◽  
Lewis M. Ward ◽  
Laura A. Pace ◽  
Woodward W. Fischer
Keyword(s):  
Genome Sequence ◽  
Genome Analysis ◽  
Draft Genome ◽  
Draft Genome Sequence ◽  
Aerobic Respiration ◽  
Obligate Anaerobe ◽  
Facultative Anaerobic

We report the draft genome sequence ofLevilinea saccharolyticaKIBI-1,a facultative anaerobic member of theChloroflexiclassAnaerolineae. WhileL. saccharolyticawas characterized as an obligate anaerobe, genome analysis provides evidence for the presence of both aerobic respiration and partial denitrification pathways.

scholarly journals Thermobrachium celere gen. nov., sp. nov., a Rapidly Growing Thermophilic, Alkalitolerant, and Proteolytic Obligate Anaerobe

1996 ◽  
Vol 46 (4) ◽  
pp. 1025-1033 ◽  
Author(s):  
M. ENGLE ◽  
Y. LI ◽  
F. RAINEY ◽  
S. DeBLOIS ◽  
V. MAI ◽  
...  
Keyword(s):  
Obligate Anaerobe
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