Enhanced biohydrogen generation from organic wastewater containing N H 4 + by phototrophic bacteria Rhodobacter sphaeroides AR-3

Abstract

is typically an inhibitor to hydrogen production from organic wastewater by photo-bacteria. In this experiment, biohydrogen generation with wild-typeanoxygenic phototrophic bacterium Rhodobacter sphaeroideswas found to be sensitive to due to the significant inhibition of to its nitrogenase. In order to avoid the inhibition of to biohydrogen generation by R. sphaeroides, a glutamine auxotrophic mutant R. sphaeroides AR-3 was obtained by mutagenizing with ethyl methane sulfonate. The AR-3 mutant could generate biohydrogen efficiently in the hydrogen production medium with a higher concentration, because the inhibition of to nitrogenase of AR-3 was released. Under suitable conditions, AR-3 effectively produced biohydrogen from tofu wastewater with an average generation rate of 14.2 mL/L·h. This generation rate was increased by more than 100% compared with that from wild-type R. sphaeroides.

Keywords

ammonium / anoxygenic phototrophic bacterium / biohydrogen / glutamine auxotrophic / tofu wastewater