实验研究了初始底物浓度对序批式培养光合细菌生长、降解及产氢过程的影响,根据最大比生长速率实验数据拟合得到其关于初始底物浓度影响的关联式,并在建立的修正Monod模型基础上建立了光合细菌比生长速率、基质比消耗速率和比产氢速率关于底物初始浓度影响的数学模型,模型预测值与实验结果在光合细菌生长期和稳定期内得到较好吻合,反映了光合细菌生长、降解和产氢过程中受底物初始浓度限制性和抑制性影响的基本规律。分析发现光合细菌生长、降解基质和产氢过程中最适底物浓度为50mmol/L,初始底物浓度低于或高于该浓度时,光合细菌生长、降解及产氢过程都受到限制性或抑制性影响,且抑制性影响较限制性影响效果更明显;底物比消耗速率受初始底物浓度影响较小。
The effect of initial substrate concentration on the growth, metabolic activities of Photosynthetic bacteria (PSB) in the process of hydrogen production is studied. The empirical relation of the initial substrate concentration to the specific growth rate, specific substrate consumption rate and specific hydrogen production rate of PSB are developed based on the modified Monod model. It is found that the results given by the model are well agreed with the experimental data in growth phase and stationary phase of PSB. Meanwhile, the optimal substrate concentration in the process of growth, metabolism and hydrogen production is 50 mmoL/L. Furthermore, when the initial substrate concentration deviates 50 mmol/L, the activation of PSB is limited or inhibited, and the inhibiting effect is more prominent than the limiting effect. In addition, it is demonstrated that initial substrate concentration has little effect on the specific substrate consumption rate.