过氧化氢酶优良基因菌株的筛选及其酶学性质研究

目的]筛选出宽pH和宽温度适应范围的过氧化氢酶高产菌株。方法]采用初筛与复筛相结合的方法筛选菌株,并采用紫外分光光度法和Amano改进滴定分析法测定酶活,经划线培养纯化获得过氧化氢酶高产菌株。结果]试验测得该菌株产过氧化氢酶的适宜pH值为6.0～8.0,适宜温度为40～50℃,最适pH值和温度分别为7.0和50℃,最高酶活可达160 U/ml,且其pH值稳定性及热稳定性均较好。结论]该试验筛选得到的过氧化氢酶高产菌株所产的过氧化氢酶具有宽泛的pH值和温度适应范围,对进一步将该过氧化氢酶基因克隆和重组到模式黑曲霉菌中进行过氧化氢酶的生产具有重要意义。

Selection of Strains Carrying the Advantageous Catalase Gene and Investigation of Some of the Properties of the Catalases

Objective] In order to get the strain which can highly produce catalase with an accommodation of an appropriate and broad pH and temperature range.Method] Strains that produces catalase were isolated from soil by means of solid plate assay method and purified by prescreening and rescreening;the activity of catalase were assayed by UV and Amano titration method.Result] A strain,which can produce catalase as much as 160 U/ml,was obtained,and the produced catalase can accommodate a broad pH(pH 6.0-8.0) and temperature(40-50 ℃) range.Its optimum pH and temperature are 7.0 and 50 ℃.Besides that,they possesse a good pH and thermal stability.Conclusion] The obtained strain can produce catalase with an accommodation of a broad pH and temperature range,and it is of practical significance to clone and express these catalase genes in a so-called model microbe,e.g.Aspergillus niger..