摘要
以北京、大连和日本3个产地的纳豆产品为试验材料,从中筛选可用于畜禽生产的纳豆芽孢杆菌(Bacillus subtilis natto)蛋白酶高产菌株。先通过酪蛋白平板初筛得到9株芽孢杆菌,再以N1型纳豆芽孢杆菌为模式菌株,对初筛得到的菌株进行菌落和菌体形态观察、生理生化鉴定,确定有5个菌株为纳豆芽孢杆菌。测定5个菌株48 h发酵液中蛋白酶活性,结果表明:菌株NB1为蛋白酶高产菌株,发酵液中蛋白酶活性为19.41 U.mL-1,产蛋白酶特性在6代内可保持稳定。
A strain of protease producing Bacillus subtilis natto was screened from natto foods which were produced in three places. 9 Bacillus were first screened with casein plate, and 5 strains were identified to be Bacillus subtilis natto by morphological, physiological and biochemical characters with Bacillu subtilis natto N1 as the model strain. A strain named NB1 was selected with the highest protease activity (19.41 U·mL^-1) through the test of protease activity in the 48h fermenting medium among the 9 strains. The stability of its protease producing is stable in 6 generations.
出处
《沈阳农业大学学报》
CAS
CSCD
北大核心
2010年第2期175-180,共6页
Journal of Shenyang Agricultural University
基金
动物营养学国家重点实验室课题[2004DA125184(团)0801]
关键词
纳豆
纳豆芽孢杆菌
蛋白酶
筛选
鉴定
natto
Bacillus subtiliss natto
protease
screening
identification