Fe(III) reduction during pyruvate fermentation byDesulfotomaculum reducensstrain MI-1

Geobiology ◽  
2013 ◽  
Vol 12 (1) ◽  
pp. 48-61 ◽  
Author(s):  
E. Dalla Vecchia ◽  
E. I. Suvorova ◽  
J. Maillard ◽  
R. Bernier-Latmani
1964 ◽  
Vol 88 (1) ◽  
pp. 4-10 ◽  
Author(s):  
R. H. Deibel ◽  
C. F. Niven

Nutrients ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1848
Author(s):  
Jungman Kim ◽  
Jae Ho Choi ◽  
Taehwan Oh ◽  
Byungjae Ahn ◽  
Tatsuya Unno

Codium fragile (CF) is a functional seaweed food that has been used for its health effects, including immunostimulatory, anti-inflammatory, anti-obesity and anti-cancer activities, but the effect of CF extracts on obesity via regulation of intestinal microflora is still unknown. This study investigated anti-obesity effects of CF extracts on gut microbiota of diet-induced obese mice. C57BL/6 mice fed a high-fat (HF) diet were given CF extracts intragastrically for 12 weeks. CF extracts significantly decreased animal body weight and the size of adipocytes, while reducing serum levels of cholesterol and glucose. In addition, CF extracts significantly shifted the gut microbiota of mice by increasing the abundance of Bacteroidetes and decreasing the abundance of Verrucomicrobia species, in which the portion of beneficial bacteria (i.e., Ruminococcaceae, Lachnospiraceae and Acetatifactor) were increased. This resulted in shifting predicted intestinal metabolic pathways involved in regulating adipocytes (i.e., mevalonate metabolism), energy harvest (i.e., pyruvate fermentation and glycolysis), appetite (i.e., chorismate biosynthesis) and metabolic disorders (i.e., isoprene biosynthesis, urea metabolism, and peptidoglycan biosynthesis). In conclusion, our study showed that CF extracts ameliorate intestinal metabolism in HF-induced obese mice by modulating the gut microbiota.


2006 ◽  
Vol 188 (2) ◽  
pp. 659-668 ◽  
Author(s):  
Kerstin Schreiber ◽  
Nelli Boes ◽  
Martin Eschbach ◽  
Lothar Jaensch ◽  
Juergen Wehland ◽  
...  

ABSTRACT Recently, we identified a pyruvate fermentation pathway in Pseudomonas aeruginosa sustaining anaerobic survival in the absence of alternative anaerobic respiratory and fermentative energy generation systems (M. Eschbach, K. Schreiber, K. Trunk, J. Buer, D. Jahn, and M. Schobert, J. Bacteriol. 186:4596-4604, 2004). Anaerobic long-term survival of P. aeruginosa might be essential for survival in deeper layers of a biofilm and the persistent infection of anaerobic mucus plaques in the cystic fibrosis lung. Proteome analysis of P. aeruginosa cells during a 7-day period of pyruvate fermentation revealed the induced synthesis of three enzymes involved in arginine fermentation, ArcA, ArcB, and ArcC, and the outer membrane protein OprL. Moreover, formation of two proteins of unknown function, PA3309 and PA4352, increased by factors of 72- and 22-fold, respectively. Both belong to the group of universal stress proteins (Usp). Long-term survival of a PA3309 knockout mutant by pyruvate fermentation was found drastically reduced. The oxygen-sensing regulator Anr controls expression of the P PA3309-lacZ reporter gene fusion after a shift to anaerobic conditions and further pyruvate fermentation. PA3309 expression was also found induced during the anaerobic and aerobic stationary phases. This aerobic stationary-phase induction is independent of the regulatory proteins Anr, RpoS, RelA, GacA, RhlR, and LasR, indicating a currently unknown mechanism of stationary-phase-dependent gene activation. PA3309 promoter activity was detected in the deeper layers of a P. aeruginosa biofilm using a P PA3309-gfp (green fluorescent protein gene) fusion and confocal laser-scanning microscopy. This is the first description of an Anr-dependent, anaerobically induced, and functional Usp-like protein in bacteria.


2019 ◽  
Author(s):  
Johannes Zimmermann ◽  
Nancy Obeng ◽  
Wentao Yang ◽  
Barbara Pees ◽  
Carola Petersen ◽  
...  

AbstractThe microbiome is generally assumed to have a substantial influence on the biology of multicellular organisms. The exact functional contributions of the microbes are often unclear and cannot be inferred easily from 16S rRNA genotyping, which is commonly used for taxonomic characterization of the bacterial associates. In order to bridge this knowledge gap, we here analyzed the metabolic competences of the native microbiome of the model nematode Caenorhabditis elegans. We integrated whole genome sequences of 77 bacterial microbiome members with metabolic modelling and experimental characterization of bacterial physiology. We found that, as a community, the microbiome can synthesize all essential nutrients for C. elegans. Both metabolic models and experimental analyses further revealed that nutrient context can influence how bacteria interact within the microbiome. We identified key bacterial traits that are likely to influence the microbe’s ability to colonize C. elegans (e.g., pyruvate fermentation to acetoin) and the resulting effects on nematode fitness (e.g., hydroxyproline degradation). Considering that the microbiome is usually neglected in the comprehensive research on this nematode, the resource presented here will help our understanding of C. elegans biology in a more natural context. Our integrative approach moreover provides a novel, general framework to dissect microbiome-mediated functions.


2021 ◽  
Vol 8 ◽  
Author(s):  
Yuxiao Liao ◽  
Dan Li ◽  
Xiaolei Zhou ◽  
Zhao Peng ◽  
Zitong Meng ◽  
...  

Background: The previous studies demonstrated that there might be complex and close relationships among leucine supplementation, gut microbiota, and muscle health, which still needs further investigation.Aims: This study aimed to explore the associations of gut microbiota with muscle health after leucine intake.Methods: In this study, 19-month-old male C57BL/6j mice (n = 12/group) were supplemented with ultrapure water, low dose of leucine (500 mg/kg·d), and high dose of leucine (1,250 mg/kg·d) for 12 weeks by oral gavage. The mice fecal samples in each group before and after supplementation were collected for baseline and endpoint gut microbiota analysis by using 16S rDNA amplicon sequencing. Meanwhile, ultrasound measurement, H&E staining, myofiber cross-sectional area (CSA) measurement, and western blotting were performed in the quadriceps subsequently. The pyruvate levels were detected in feces.Results: Improvement in muscle of histology and ultrasonography were observed after both low and high dose of leucine supplementation. High dose of leucine supplementation could promote skeletal muscle health in aging mice via regulating AMPKα/SIRT1/PGC-1α. The richness and diversities of microbiota as well as enriched metabolic pathways were altered after leucine supplementation. Firmicutes-Bacteroidetes ratio was significantly decreased in high-leucine group. Moreover, pyruvate fermentation to propanoate I were negatively associated with differential species and the pyruvate levels were significantly increased in feces after high dose of leucine supplementation.Conclusions: Chronic high dose of leucine supplementation changed gut microbiota composition and increased pyruvate levels in the feces, which possibly provides a novel direction for promoting muscle health in aging mice.


2012 ◽  
Vol 86 (4) ◽  
pp. 819-835 ◽  
Author(s):  
Olga E. Petrova ◽  
Jill R. Schurr ◽  
Michael J. Schurr ◽  
Karin Sauer

2016 ◽  
Vol 124 ◽  
pp. 38-44 ◽  
Author(s):  
Hongjuan Zhang ◽  
Yang Lu ◽  
Siping Wu ◽  
Yu Wei ◽  
Qian Liu ◽  
...  

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Stephan Köstlbacher ◽  
Astrid Collingro ◽  
Tamara Halter ◽  
Frederik Schulz ◽  
Sean P. Jungbluth ◽  
...  

AbstractChlamydiae are highly successful strictly intracellular bacteria associated with diverse eukaryotic hosts. Here we analyzed metagenome-assembled genomes of the “Genomes from Earth’s Microbiomes” initiative from diverse environmental samples, which almost double the known phylogenetic diversity of the phylum and facilitate a highly resolved view at the chlamydial pangenome. Chlamydiae are defined by a relatively large core genome indicative of an intracellular lifestyle, and a highly dynamic accessory genome of environmental lineages. We observe chlamydial lineages that encode enzymes of the reductive tricarboxylic acid cycle and for light-driven ATP synthesis. We show a widespread potential for anaerobic energy generation through pyruvate fermentation or the arginine deiminase pathway, and we add lineages capable of molecular hydrogen production. Genome-informed analysis of environmental distribution revealed lineage-specific niches and a high abundance of chlamydiae in some habitats. Together, our data provide an extended perspective of the variability of chlamydial biology and the ecology of this phylum of intracellular microbes.


Sign in / Sign up

Export Citation Format

Share Document