高糖化酶活菌株的选育及其在山西老陈醋酿造中的应用

采用N~+注入、氯化锂-紫外线复合诱变方法对糖化酶生产菌株黑曲霉As3.4309反复进行诱变处理,获得了1株高糖化酶活的突变株IV5-66,其糖化酶活力为出发菌株的3.5倍,该菌株具有无霉腐味、不产生色素等特点,具有较高的应用价值。建立了利用该突变株制备高糖化酶活麸曲的工艺,并将高糖化酶活麸曲与我们已经构建的产酒生香酵母菌共培养液共同添加到山西老陈醋的酒醪发酵中,使淀粉利用率提高了27%,乙醇产量提高了34%,乙酸乙酯产量提高了1倍,酒醪的产量与质量均得到了大幅度的提高。

Breeding of Aspergillus niger for the High-yield Glucoamylase Strain

In this paper,the parent strain of Aspergillus niger 3.4309 was treated with the mutagensis of N~+ implantation and UV-LiCl.A mutant strainⅣ5—66 with high production level of Glucoamylase was screened.Compared to the parent strain,its enzymatic activity was 3.5 times higher than the parent strain, with the characterization of no pigment and no fustiness.So it was worth of higher application in brewing. And the high-glucoamylase bran-koji of the mutant strain was made.The bran—koji and the mixed—culture system of yeasts for high production of alcohol and ethyl acetate were added to brew the Shanxi overly ma- tured vinegar.The results indicated that the utility of starch was increased by 27%,and the yield of alcohol and ethyl acetate was increased by 34% and 100%,respectively,which greatly improve the yield and the quality of alcohol.