【摘要】 通过平板划线分离法,从15份土样中筛选到18株产耐热脂肪酶菌株。经复筛选取K2菌进行产酶条件研究,并通过盐析沉淀法分离脂肪酶,研究该酶最佳催化条件。实验结果表明,该菌株产脂肪酶的适宜发酵条件为培养温度55℃,初始pH5,摇床转速200 r/min,发酵时间48 h。采用硫酸铵分30%与75%两步盐析分离脂肪酶,经真空低温冷冻干燥浓缩酶液,用pH 6.0磷酸缓冲液溶解后,在50℃,pH=7条件下,对乳化橄榄油具有最高催化活性。更多还原

【Abstract】 By the method of solid plate,from 15 soil samples screened 18 strains producing thermostable lipase strains.Through studing conditions of enzyme production of K2,and by salting-out sedimentation separation of lipase,the optimal catalytic conditions of the enzyme were studied.The experimental results showed that the optimum fermentation conditions of the strain producing lipase were culture temperature 55 ℃,initial pH 5,shaking speed 200 r/min,and fermentation time 48 h.By using ammonium sulfate by 30% and 75% two steps of salting out of lipase,vacuum freeze-drying concentrated enzyme solution,dissolution in the phosphate buffer solution(pH 6.0),at 50 ℃,and pH=7,the highest catalytic activity was got for emulsified olive oil.更多还原