Effect of initial substrate concentration on dynamic characteristic of hydrogen production by photosynthetic bacteria
底物初始浓度对光合细菌产氢动力学特性的影响

The effect of initial substrate concentration on the dynamic characteristics of hydrogen production by photosynthetic bacteria(PSB) was studied in the experiment,and metabolism of hydrogen production was analyzed by comparing the ratio between quantity of hydrogen produced and initial substrate quantity to that between quantity of hydrogen produced and quantity of consumed substrate.It was found that the optimal initial substrate concentration of hydrogen production by PSB was 120 mmol/L,when initial substrate concentration came to 140 mmol/L PSB would mostly synthesize biomass and acidic product,and the maximum biomass among all initial substrate concentrations was gained.However,the metabolism of hydrogen production was restrained.This indicated that there was no direct proportion between the maximum biomass and the maximum hydrogen production rate,and the mechanism of CO2 production was different from that of H2 production.Meanwhile,the maximum specific ratio of hydrogen production of PSB was found in exponential phase,while maximum biomass was found in steady phase.On the other hand,the fact that initial substrate concentration influence obviously on exponential phase of PSB was found,when initial substrate concentration was smaller the maximum biomass was gained earlier,whereas the maximum biomass was gained latter when initial substrate concentration was bigger.