摘要
以编号为J1-1的黑曲霉为出发菌株,通过超声波和紫外诱变处理,在酪蛋白培养基上以凝乳圈直径为指标进行初筛,在基础固态发酵培养基上进行复筛,选育得到一株具有良好遗传稳定性的突变菌株。其经固态发酵凝乳酶产量为凝乳活力600U/mL,较出发菌株J1-1提高57%。菌株经8次传代培养,凝乳酶产量仅降低7.1%。在此基础上应用单因素试验和正交设计对菌株产凝乳酶的固态发酵条件进行了系统研究和优化,得到最佳的试验组合为发酵温度28℃,发酵时间为6d,加水量为20mL,加样量为4份。采用此条件,凝乳酶产量达828U/mL,比J1-3优化前提高38%。
Aspergillus niger J1-Iwas used as parent strain to be mutated by ultrasonic and UV treatment. Preliminary screening was based on size of milk-clotting zones and the secondary screening was done on solid fermentation medium. A mutant strain J1-3 with good genetic stability and high milk-clotting activity was screened. The enzyme activity of the mutant strain reached 600U/ml in solid state fermentation, which was 57% higher than that of the parent strain. A decrease of 7.1% in the enzyme yield of the mutant was observed after eight times of subculture. Furthermore, the fermentation conditions of the mutated strain were optimized by single factor design and orthogonal design. The optimal fermentation conditions were as followed： fermentation temperature 2℃, fermentation time 6d, water 20mL and added sample 4. Under these conditions, the enzyme activity was 828U/mL, which was 38% higher than that before optimization.
出处
《中国酿造》
CAS
北大核心
2011年第2期41-45,共5页
China Brewing
基金
国家高技术研究发展计划(863计划)(2006AA10Z306)
农业部现代农业产业技术体系建设专项资金资助项目(nycytx-0502)
国家公益性行业(农业)科研专项经费项目(200903043)资助
中国博士后科学基金资助项目(20100471246)资助
吉林省博士后科研项目启动经费(04006)资助
关键词
凝乳酶
黑曲霉
菌种诱变
优化
milk-clotting enzyme： Aspergillus niger： strain mutagenesis
optimization
