通过N+注入、氯化锂一紫外线复合诱变方法选育了一株高产糖化酶黑曲霉IN7-31(Aspergillus niger)菌株,采用响应面法对该菌株产糖化酶的液态发酵工艺条件进行了优化.首先,通过前期的预实验,筛选出了对发酵工艺影响较大的三个培养基成分和两个培养条件,然后,分别对这两组进行了最陡爬坡实验,用最陡爬坡试验逼近最大响应区域,通过中心组合实验及响应面法分析优化了这几个因素,并进行了优化后的验证实验.利用SAS软件分析得到该菌株产糖化酶的最佳工艺条件为:玉米粉56.5g/L,豆粉22.0g/L,K2HPO41.3g/L,pH值为6.40,装液量80.8mL/250mL三角瓶,在此条件下摇瓶发酵黑曲霉产糖化酶的最大酶活为3044U/mL,比优化前提高了1.59倍.结果表明,通过响应面试验得到了产糖化酶黑曲霉液态发酵最佳工艺条件,可以为糖化酶的工业化生产提供一定的技术参数与条件.%A high glucoamylase-producing Aspergillus niger IN7-31 was obtained by mutagensis of N+ implantation and UV-LiCl.Fermentation conditions were optimized with response surface methodology(RSM).Firstly, 3 ingredients of medium and 2 cultivation conditions significantly affect fermentation were selected by pre-experiment.The two groups were carried out by steepest ascent experiment, using the path of steepest ascent tests to approach the largest response region.RSM were applied to determine the optimal concentration of each significant variable.The optimum conditions for glucoamylase production were determined by SAS software, which were as follows: com flour 56.5g/L, soybean meal 22.0g/L, K2HPO4 1.3g/L, pH value 6.40,and medium loading rate of 80.8ml per 250ml flask.The maximum glucoamylase activity under the optimum conditions was 3044U/ml, which was 59％ higher than that of the original medium.The results of the study will provide some of the technical parameters for the industrial production of glucoamylase.
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