Screening and H₂-producing characters of a high efficient H₂-producing mutant RF-9

Ethanoligenens sp. ZGX4 the anaerobic hydrogen producing (HP) bacterium isolated from a continuous stirred tank reactor (CSTR) was used as wild parent strain, through UV and nitrous acid combined mutation, a stable highly effective HP strain RF-9 was screened from large amount of mutant. At cultural condition of phosphate of 120 mmol/L, temperature of 37°C, original pH of 6.0 and glucose concentration of 10 g/L, unit volume HP amount and hydrogen yield were 139.7mmol/L and 2.52mol H₂/mol glucose, being 1.50 and 1.43 times of the contrast respectively. At fermentation time of 15h, pH 4.1 and cell dry weight of 0.722 g/L, RF-9 obtained its maximal HP rate of 345mL H₂/(h-L) being its contrast 1.41 times. The main liquid end products of RF-9 were ethanol and acetic acids, being the typical ethanol fermentation bacteria, similar to the contrasts.