Molecular characterization and transcriptional analysis of the putative hydrogenase gene of Clostridium acetobutylicum ATCC 824

The putative hydrogenase gene (hydA) in Clostridium acetobutylicum encoding a 64,415-Da protein shows a high degree of similarity with the (Fe) hydrogenase genes of Desulfovibrio and Clostridium species. The hydA mRNA content is high in cells from an acidogenic or alcohologenic continuous culture and low in those from a solventogenic continuous culture. The regulation of hydA expression occurs at the transcriptional level.