He-Ne激光诱变选育产氢拜氏梭菌

采用He-Ne激光器对拜氏梭菌(Clostridium beijerinckii)进行激光诱变育种,对激光诱变参数进行优化,结果表明,随着照射剂量的变化,存活率随之变化,输出功率和辐射时间均由正突变率决定。在最佳照射条件(19 m W,16 min)下,得到稳定的阳性突变株BH4。在初始葡萄糖浓度为10 g/L的分批培养中,突变株每克葡萄糖的最终产氢量为260. 7 m L,比野生菌高出28. 9%。酶测定显示,诱变后氢化酶活性增加,这可能有助于提高产氢量。此外,研究了分批培养物中突变体BH4及其野生菌的动力学,其初始葡萄糖浓度为1～10 g/L。动力学参数还表明,突变菌比其野生菌具有更强的产氢能力。说明该He-Ne激光诱变育种技术可以在产氢微生物领域中应用。

Screening of hydrogen-producing Clostridium beijerinckii by He-Ne Laser Mutagenesis

Clostridium beijerinckii was irradiated by He-Ne laser to optimize the laser mutagenesis condition. The results showed that the survival rate changed regularly with the variation of irradiation dose, and high positive mutation frequency was determined by both the output power and exposure time. Under the optimum irradiation condition (19 mW for 16 min), a stable positive mutant strain BH4 was obtained. In the batch culture with initial glucose concentration of 10 g/L, the final hydrogen yield of the mutant strain was 260.7 mL/g-glucose, which was 28.9% higher than that of the wild strain. The enzyme assay show that the hydrogenase activity increased after mutagenesis, which presumably contribute to the improvement of hydrogen production. In addition, the kinetics of the mutant BH4 and its wild strain in batch cultures are investigated with initial glucose concentrations from 1 to 10 g/L. The kinetic parameters also demonstrate that the mutant strain possess a more prominent ability to produce hydrogen than its wild strain. The results show that He-Ne laser mutagenesis could be applied in the field of hydrogen-producing microorganisms.