title: Polarized potential and electrode materials implication on electro-fermentative di-hydrogen production: Microbial assemblages and hydrogenase gene copy variation.
abstract: This study examined the changes in microbial diversity in response to different electrode materials viz., stainless steel mesh (SS) and graphite plate as anodes in two microbial electrolysis cell (MEC) each poised at 0.2V, 0.4V, 0.6V and 0.8V. Changes in microbiota prior to and after pretreatment along with microbiota enriched in response to various poised potentials with SS and graphite are monitored by 16S rRNA gene based DGGE profiling. Significant shifts in microbial community were noticed at all these experimental conditions. Correspondingly, the level of hydrogenase belonging to genera Bacillus, Pseudomonas, Rhodopseudomonas and Clostridium was studied by quantitative real time PCR (RT-PCR) at various applied potentials. DGGE based 16S rRNA gene profiling revealed enriched members belonging to phylum Firmicutes predominantly present at 0.8V in both MECs contributing to high hydrogen production. This study first time explored the growth behavior of mixed consortia in response to poised potentials and electrode materials.
authors.affiliation: Bioengineering and Environmental Sciences, CSIR-Indian Institute of Chemical Technology, Hyderabad 500 007, India.
authors.forename: Kotakonda
authors.initials: K
authors.lastname: Arunasri
authors.affiliation: Bioengineering and Environmental Sciences, CSIR-Indian Institute of Chemical Technology, Hyderabad 500 007, India.
authors.forename: J
authors.initials: J
authors.lastname: Annie Modestra
authors.affiliation: Bioengineering and Environmental Sciences, CSIR-Indian Institute of Chemical Technology, Hyderabad 500 007, India.
authors.forename: Dileep Kumar
authors.initials: DK
authors.lastname: Yeruva
authors.affiliation: Bioengineering and Environmental Sciences, CSIR-Indian Institute of Chemical Technology, Hyderabad 500 007, India.
authors.forename: K
authors.initials: K
authors.lastname: Vamshi Krishna
authors.affiliation: Bioengineering and Environmental Sciences, CSIR-Indian Institute of Chemical Technology, Hyderabad 500 007, India. Electronic address: vmohan_s@yahoo.com.
authors.forename: S
authors.initials: S
authors.lastname: Venkata Mohan
mesh_terms: D001419:Bacteria / Q000235:genetics / Q000378:metabolism*; D044822:Biodiversity; D001674:Bioelectric Energy Sources / Q000382:microbiology; D019149:Bioreactors / Q000382:microbiology; D058645:Denaturing Gradient Gel Electrophoresis; D004566:Electrodes; D004572:Electrolysis / Q000379:methods*; D005285:Fermentation; D018628:Gene Dosage; D005798:Genes, Bacterial; D006859:Hydrogen / Q000378:metabolism*; D006864:Hydrogenase / Q000235:genetics*; D010084:Oxidation-Reduction; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S; D062065:Wastewater / Q000737:chemistry
chemical_list: D006859:Hydrogen; D006864:Hydrogenase; D012336:RNA, Ribosomal, 16S; D062065:Wastewater
keywords: DGGE profiling; Electrode materials; Microbial electrolysis cell; Poised potential; qRT-PCR