庆阳市传统发酵豆瓣酱中高产蛋白酶霉菌的筛选与鉴定

Isolation and identification of high yield protease mold in traditional fermented soybean paste of Qingyang City

为优选庆阳市传统发酵豆瓣酱高产蛋白酶霉菌,以甘肃庆阳5县区20个自然发酵豆瓣酱为材料,采用察氏培养基分离纯化、平板透明圈法初筛,发酵液蛋白酶活力复筛,通过孢子数测定和菌体形态观察鉴定及18S rDNA分子生物学鉴定.结果表明:所分离出的11株霉菌株中9株具有分解蛋白质的能力,其中BDH5蛋白酶活性最高,达到了4 351.68 U/g.对BDH5初步鉴定及18SrDNA鉴定,所优选的BDH5菌种为米曲霉(Aspergillus tamarii).

To gain the high yield protease mold strains of traditional fermented soybean paste in Qingyang City,20 experimental samples were collected from self-made soybean paste by peasant household in 5counties of Qingyang City,using plate streaking purified predominant strains,protease fermentation broth determination of rescreening,measured by the number of spores and bacterial morphology preliminary and identification of 18 SrDNA molecular biology.The results showed that the total of 11 predominant strains were isolated,and 9of them with resolve ability on protein.The protease activity of BDH5 was the highest,which reached to 4 351.68U/g.By preliminary identification combined with 18 SrDNA identification,the BDH5 was identified as Aspergillus tamarii.