红假单胞菌Rhodop seudomonas rutila自养固定CO_2特性研究

Study of carbon dioxide fixation by Rhodopseudomonas rutila

采用分批培养,初始气相CO2体积分数为10%,血色红假单胞菌Rhodopseudomonasrutila固定CO2的最佳培养条件是:NH4Cl0.5g.L-1,K2HPO4.3H2O5g.L-1,MgSO4.7H2O0.2g.L-1,生长因子10mL.L-1,微量元素10mL.L-1,pH8.5,转速100～150r/min,不添加NaCl.在此条件下培养5d,CO2固定率能够达到56%.培养24h后,其固定CO2主要是通过卡尔文循环,该循环关键酶1,5-二磷酸核酮糖羧化酶(Rubisco)的活性不断提高,在菌体生长到对数中期时达到最大.

When the volume fraction of CO2 in gas mixture is 10%, the optimal condition for CO2 fixation by Rhodopseudomonas rutila is obtained as follows: NH4Cl 0.5 g·L-1, K2HPO4·3H2O 5 g·L-1, MgSO4·7H2O 0.2 g·L-1, growth factor 10 mL·L-1, trace elements 10 mL·L-1, pH 8.5 and rotation speed 100~150 r/min and without NaCl. The fixation ratio of CO2 by the strain can reach 56% within 5 days and CO2 is assimilated through the Calvin reductive pentose phosphate (Calvin cycle). After the strain is autotrophically cultured for 24 hours, the activity of 1,5ribulose bisphosphate carboxylase (Rubisco) gradually increases and the highest activity is reached when the strain is in mid phase of logarithmic growth.