Photo-fermentation hydrogen production by Rhodopseudomonas sp. nov. strain A7 isolated from the sludge in a bioreactor

Abstract

A photo-fermentative bacterium for hydrogen production, Rhodopseudomonas sp. nov. strain A7, was isolated from sludge in a running bioreactor. The strain A7 has a flagellum and capsule. The hydrogen production performance exhibited by the strain A7 under several key parameters was investigated in batch culture. The maximum hydrogen yield achieved was160 ml-H2/60 ml-vessel using 60 mmol/l acetate, 15 mmol/l glutamate at a pH 7.0 and an inoculum time of 14 h. This study determined that the strain A7 can utilize glucose and, especially, fructose and sucrose for cell growth and hydrogen production. The hydrogen yield obtained with these substrates reached 33, 30 and 43 ml-H2/60 ml-vessel, respectively. These results imply that the strain A7 possesses a wide range of substrate utilization capabilities and is a potential candidate for photo-hydrogen production.