Firmicutes with iron dependent hydrogenase drive hydrogen production in anaerobic bioreactor using distillery wastewater

Acidic and alkaline shock pretreatment to enrich acidogenic biohydrogen producing mixed culture: long term synergetic evaluation of microbial inventory, dehydrogenase activity and bio-electro kinetics

“…The acid-pretreated culture showed dominance of firmicutes followed by proteobacteria, uncultured bacterium (IICTSVMH22, IICTSVMH23), bacteroidia and actinobacteria. Firmicutes are reported to be effective H 2 producers 35,36 and have the capability to grow in acidogenic microenvironment forming endo-spores in adverse conditions, 30,37,38 which substantiate its presence in the acidogenic reactors. Clostridia were found to have iron dependent hydrogenase ([FeFe]-hydrogenase) as the dominant functional gene, which has higher activity than [NiFe]-hydrogenase.…”

“…Clostridia were found to have iron dependent hydrogenase ([FeFe]-hydrogenase) as the dominant functional gene, which has higher activity than [NiFe]-hydrogenase. 36 The alkaline-pretreated culture showed dominance of Proteobacteria class followed by Firmicutes, Uncultured bacteria and Actinobacteria/Bacteroidia which was more or less similar to the parent inoculum with additional presence of Clostridium (Uncultured Ruminococcaceae) and Bacillus (Lysinibacillus xylanilyticus, Uncultured Ruminococcaceae, Bacillus boroniphilus, Bacillus cereus, Bacillus thuringiensis, Uncultured Bacillus sp.) species.…”

Biocathode in microbial electrolysis cell; present status and future prospects

“…Two clones associated with Bacteroidetes and Firmicutes phyla were identified in the bioanode which were previously reported in anodes of various MFCs [56,57]. Rhodopseudomonas palustris was assessed as the dominant species in the cathodic bioelectrode which had Ni-Fe and Fe-Fe-hydrogenases, and was a known species in hydrogen production processes [57][58][59][60]. In an extensive experimental research, Croese et al [38] [38].…”

“…Following the proof-of-principal of a full biological two-chambered MEC by Jeresmiasse et al [41], microbial diversity of the bioanode and biocathode was scrutinised in a MEC developed with similar start-up procedures as Rozedal et al [25] and Jeresmiasse et al [41]; it was inoculated with a mixed culture [49]. Two clones associated with Bacteroidetes and Firmicutes phyla were identified in the bioanode which were previously reported in anodes of various MFCs [56,57]. Rhodopseudomonas palustris was assessed as the dominant species in the cathodic bioelectrode which had Ni-Fe and Fe-Fe-hydrogenases, and was a known species in hydrogen production processes [57][58][59][60].…”

Regulating biohydrogen production from wastewater by applying organic load-shock: Change in the microbial community structure and bio-electrochemical behavior over long-term operation

“…cellulosi was predominant species in cow dung compost capable of producing H 2 effectively that forms spherical terminal endospores and decomposes cellulose, with the production of H 2 , CO 2 , acetate and ethanol as fermentation end products. Clostridia were found to have iron dependent hydrogenase ([FeFe]-hydrogenase) as dominated functional gene which has 100 times higher activity than [NiFe]-hydrogenase [27]. B. subtilis is a rod-shaped gram/catalase positive bacterium that has the ability to form a protective endospore that allows the organism to tolerate extreme conditions [28,29].…”