诱变育种选育高效产氢细菌

BREEDING HINGH EFFICIENT HYDROGEN-PRODUCING BACTERIA BY MUTAGENESIS

从自行研制的CSTR反应器中分离出一株产氢发酵细菌Ethanoligenens sp.ZGX4,以其为出发菌株,进行紫外和亚硝酸复合诱变选育,经过连续传代得到一株遗传稳定性很好的高效产氢突变株YR-3。在培养条件分别为36±1℃,初始pH为6.0,葡萄糖浓度为12g/L,其单位体积产氢量(Y_H_2)为3097.5mL/Lculture,产氢能力比对照提高70.5%,最大产氢速率为36.6mmol/g·drycell·h,比对照高出55.1%;发酵液相末端产物是以乙醇和乙酸为主的典型乙醇型发酵代谢类型。高效产氢耐酸突变体YR-3的释氢能力和产氢速率明显高于野生菌株ZGX4,显示了较强的商业应用潜力,也可为以后进一步探讨研究乙醇型细菌的制氢机制及代谢途径提供物质材料。

The fermentative hydrogen bacteria Ethanoligenens sp. ZGX4 was separated from a CSTR reactor, and as an original strain, the bacteria was mutated and bred by UV and nitrous acid combined treatment. A high efficient hydrogenproducing mutant YR-3 with better stability was obtained after continuous passages. When temperature, original pH and glucose concentration were 36 ± 1℃, 6.0 and 12g/L, respectively, the hydrogen-producing capacity （ YH2 ） of YR-3 was 3097.65 mL/L-culture, its hydrogen-producing ability increased 70.5% over that the parent strain; The maximal I-I2 yield rate Q~ was estimated to be 36.6 mmol H2/g＂ drycell＇h, which was improved 55.1%, the main metabolic end product of mutant YR-3 was ethanol and acetic acid. In each case, YR-3 produced hydrogen at a faster rate and a stronger ability than the wild type, showing a possible potential for commercial hydrogen production and it would also provide useful data for exploring hydrogen-preducing mechanism and metabolic pathway of hydrogen-producing bacteria.