Transcription of [FeFe]-Hydrogenase Genes during H₂ Production in <i>Clostridium</i> and <i>Desulfovibrio</i> spp. Isolated from a Paddy Field Soil

Abstract

Changes in the relative abundances of the transcripts of hydA gene paralogs for [FeFe]-hydrogenase in Clostridium sp. strain H2 and Desulfovibrio sp. strain A1 isolated from paddy field soil were analyzed during H 2 production. Strains H2 and A1 had at least five and two phylogenetically different hydA genes, respectively. The relative abundances of their hydA transcripts differed among the paralogs and H 2 production activity changed in a manner that depended on the growth phase and conditions. Increases or decreases in the relative abundances of the transcripts of two out of five hydA genes in strain H2 correlated with changes in H 2 production rates, whereas those of the others remained unchanged or decreased. In strain A1, the relative abundances of the transcripts of two hydA genes differed between monoculture, sulfate-reducing, and syntrophic, methanogenic conditions. The relative abundance of the transcripts of one hydA gene, predicted to encode a cytosolic [FeFe]-hydrogenase, was higher under syntrophic, methanogenic conditions than sulfate-reducing conditions, while that of the transcripts of the other hydA gene decreased with time under both conditions. This study showed that the transcription of the hydA gene during growth with active H 2 production was differently regulated among the paralogs in H 2 producers isolated from paddy field soil.

Improving sustainable hydrogen production from green waste: [FeFe]-hydrogenases quantitative gene expression RT-qPCR analysis in presence of autochthonous consortia

“…This technique has already been used for quantification of [FeFe]-hydrogenases and has proven to be an accurate assay for quantification of hydrogenase expression levels either in single or mixed bacterial cultures. Nonetheless, the previous studies of hydrogenases genes expression developed in various microorganisms have focused on a single [FeFe]-hydrogenase gene only in bioreactors or multiple [FeFe]-hydrogenase genes expression analysis only in pure cultures [ 13 , 35 , 49 – 51 ] or, when in syntrophic co-cultures, only under very controlled and simplified conditions and in rich media [ 50 , 52 ]. Other studies performed on real complex matrices only provided an estimate of the hydrogen-producing consortium composition by meta-trascriptomic analysis and were not quantitative [ 45 ].…”

“…strain H2 RT-qPCR Under fermentation conditions, Widdel’s freshwater medium pure cultures Hydrogen production H2hydA1 H2hydA2 H2hydA3 H2hydA4 H2hydA5 corresponding to hydA genes of C. bifermentans ATCC 638 (AVNC00000000) and ATCC 19,299 (AVNB00000000) [ 50 ] Desulfovibrio sp. strain A1 and AH1 RT-qPCR Under sulphate-reducing conditions modified Widdel’s freshwater medium pure cultures Hydrogen production A1hydA1 A1hydA2 corresponding to hydA genes of D. vulgaris Hildenborough (AE017285) [ 50 ] Clostridium butyricum CGS5 RT-PCR and qPCR PM medium Pure culture Hydrogen production h ydA [ 51 ] Thermotoga neapolitana and Caldicellulosiruptor saccharolyticus Quantitative Real-time PCR Synthetic co-culture Hydrogen production hydA from Thermotoga neapolitana [ 52 ] Clostridium thermocellum ATCC 27,405 Real-time quantitative PCR Continuous pure culture on Modified Dehority medium containing (per litre) 3.0 g of cellobiose or 2.7 to 3.1 g of Sigmacell 20 microcrystalline cellulose Fermentation of Cellulose or Cellobiose hydA [ 53 ] Clostridium beijerinckii AM2 and Clostridium tyrobutyricum AM6 RT-qPCR Green waste with autochthonous microbiota and co-addition of both strains Hydrogen production on green waste Cbei_1773 Cbei_0327 Cbei_1901 Cbei_4110 Cbei_3796 Cbei_4000 Ctyr_hydA (FJ226584) ...…”