摘要
【目的】建立对糖化酶生产菌种黑曲霉随机突变文库进行筛选的方法,以获得糖化酶酶活提高的突变菌株。【方法】以一株可产糖化酶的黑曲霉菌株Aspergillus niger X1为出发菌株,经硫酸二乙酯诱变获得突变文库,采用葡萄糖的结构类似物——2-脱氧葡萄糖进行筛选,并在筛选过程中逐渐提高2-脱氧葡萄糖浓度,定向选育具有2-脱氧葡萄糖抗性、高产糖化酶的突变株。【结果】获得的高产突变菌株DG36摇瓶发酵糖化酶产量比出发菌株A.niger X1提高22.2%–33.8%,经工业水平50 m^3罐发酵测试,突变株DG36发酵128 h糖化酶活可达49094 U/m L,在相同发酵时间内,其酶活较出发菌株A.niger X1提高32.8%,发酵时间缩短16.9%。【结论】本研究开发了一种以2-脱氧葡萄糖为抗性标记选育高产糖化酶突变株的方法,所得突变株DG36遗传性状稳定,与出发菌相比具有菌丝粗壮、产酶期提前、糖化酶活高、发酵时间短、有利于发酵后处理的优点。
[Objective] To obtain mutants of Aspergillus niger with high glucoamylase activity, we developed a screening method. [Methods] We mutagenized the starting strain A. niger X1 using diethyl sulfate, then cultured the mutant library on agar plate containing 2-deoxyglucose. By increasing the concentration of 2-deoxyglucose, we obtained mutants with high resistance to 2-deoxyglucose and then studied glucoamylase activities. [Results] In shake flask fermentation, glucoamylase activity of the mutant strain A. niger DG36 increased by 22.2% to 33.8%. In a 50 m3 fermenter, glucoamylase activity of the strain DG36 reached up to 49094 U/mL at 128 h, 32.8% higher than that of the starting strain A. niger X1. As a result, the fermentation period of the strain DG36 was reduced by 16.9% compared with A. niger X1. [Conclusion] Mutant strain DG36 exhibited higher glucoamylase activity, shorter fermentation period and more suitable for the purification treatment than the starting strain A. niger X1.
作者
张天瑞
赵秋伟
李正华
李寅
张延平
Tianrui Zhang Qiuwei Zhao Zhenghua Li Yin Li Yanping Zhang(National Engineering Laboratory for Industrial Enzymes, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China)
出处
《微生物学报》
CAS
CSCD
北大核心
2017年第8期1293-1300,共8页
Acta Microbiologica Sinica
关键词
黑曲霉
糖化酶
2-脱氧葡萄糖
诱变
硫酸二乙酯
工业应用
Aspergillus niger, glucoamylase, 2-deoxyglucose, mutation, diethyl sulfate, industrial application
