Yao Ting-Ting, Wang Yan-Min, Gu Jian-Long, Wang Zheng-Xiang
The Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Southern Yangtze University, Wuxi 214036, China.
Sheng Wu Gong Cheng Xue Bao. 2006 Jul;22(4):567-71. doi: 10.1016/s1872-2075(06)60045-9.
The glucoamylase gene (glaA) of Aspergillus niger CICIM F0410 was cloned, sequenced and expressed. The integrated plasmid pBC-Hygro-glaA carrying the glaA was constructed and transformed into A. niger F0410. Transformants with multiple copies of glaA integrated in the chromosome were selected by 150 microg/mL hygromycin B and identified by real-time PCR. Two to three multiples of glaA in the chromosome were found to be optimal for higher expression of glucoamylase. Shake-flask fermentation under optimal conditions showed that glucoamylase secreted by the transformant GB0506 was 17.5% higher than parental strain F0410 at the end of fermentation. In conclusion, increasing copy number of glaA by chromosomal integration significantly improves the yield of glucoamylase in the industrial strain of A. niger.
对黑曲霉CICIM F0410的糖化酶基因（glaA）进行了克隆、测序和表达。构建了携带glaA的整合质粒pBC-Hygro-glaA，并将其转化到黑曲霉F0410中。通过150μg/mL潮霉素B筛选出染色体上整合有多个glaA拷贝的转化子，并通过实时PCR进行鉴定。发现染色体上glaA的两到三个拷贝对于糖化酶的更高表达是最佳的。在最佳条件下进行摇瓶发酵表明，在发酵结束时，转化子GB05所分泌的糖化酶比亲本菌株F0410高17.5%。总之，通过染色体整合增加glaA的拷贝数可显著提高黑曲霉工业菌株中糖化酶的产量。
