In order to obtaining high producing alkaline protease strains, 20 strains are found containing the ability to produce alkaline protease after screening from sea muds.5 strains with higher activity are obtained after secondary screening.Among them, the strain SDL9 not only has a strong ability to produce alkaline protease, but also has an extensive tolerance of pH.The effects of single factor including pH, culture temperature, culture time, the volume of liquid, and vaccination quantity on producing alkaline protease of SDL9 are investigated.Then the orthogonal test is used to analyze optimization conditions.The results showed that the optimal culture conditions are pH 9.0, the culture time 18 h, the volume of liquid 20 mL medium/50 mL flask and vaccination quantity 3%.The most important factor affecting enzyme activity is pH, followed by culture time, vaccination quantity and the volume of liquid, respectively.The activity of alkaline protease of fermentation broth could reach to 197.58 U/mL in the optimal conditions.The study shows that the high producing strains of alkaline protease can be got from Qinhuangdao sea area.The microorganism resources is abundant.%为了获得碱性蛋白酶高产菌株,从采集的海泥中筛选得到20株具有一定产碱性蛋白酶能力的菌株,经过复筛得到5株产酶能力较高的菌株,其中菌株SDL9产碱性蛋白酶能力强、pH耐受范围广.考察了培养基初始pH值、培养温度、培养时间、装液量、接种量等单因素对菌株SDL9产酶能力的影响,然后进行正交试验分析,得出该菌的较佳发酵条件为pH值9.0、发酵时间18h、20 mL培养液/50 mL三角瓶和接种量3％.影响产酶的强弱顺序为:pH值、培养时间、接种量、装液量,菌株SDL9在较佳发酵条件下的发酵液的最大酶活力达197.58 U/mL.本研究表明从秦皇岛海域可以获得碱性蛋白酶高产菌株,丰富了菌种资源.
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