高产淀粉酶菌株的分离及发酵工艺改良

Separation of High Produce Amylolytic Enzyme Producing Strain and the Optimization of Fermentation Process

从自然界中筛选高产淀粉酶菌株,为工业生产淀粉酶提供储备菌株。利用淀粉水解圈直径与菌落的直径比和单糖含量为指标,筛选出高产淀粉酶的菌株,运用均匀试验设计,结合DPS数据处理软件分析,从温度和pH值两方面改良并优化发酵条件,提高菌株产酶能力。结果表明,经筛选后得到的产淀粉酶菌株为米曲霉QA96.8(Aspergillus oryzae),最佳发酵条件为:温度40℃,培养基pH值4.0。由其发酵所得的淀粉酶最适反应温度为55℃,最适作用pH值5.0,同时测得酶活力为3900U/mL。

To separate and screen high produce amylolytic enzyme producing strain from nature, in order to stock strain for industrial production of amylolytic enzyme.Screening high produce strain by the diameter of amylolytic hydrolyze circle and content of monosaccharose. Ferment situation （temperature and pH value） have been improved to upgrate the enzymatic production by applying uniform experimental design with DPS statistical analysis software.The results show that the chosen strain is Aspergillus oryzae QA96.8 （Aspergillus oryzae） , and the optimum ferment situation is 40 ℃, and the pH value of culture medium is 4.0. The optimum temperature for the amylolytic enzyme is 55 ℃, and the best pH value is around 5.0. Under this condition, the amylolytic enzyme activity is 3 900 U/mL.