产脂肪酶菌株L42的筛选及最佳生长条件的研究

Study on Selection and Fermenting Conditions of a Lipase-production Bacterium L42

从连云港海域的海水、海底沉积物等样品中分离筛选产脂肪酶的菌株,经初筛复筛后得L42菌株产脂肪酶酶活较高。菌株细胞大小（0.2-0.5）μm×（1.0~1.5）μm,杆状,革兰氏染色阴性,无芽孢,有单端鞭毛。对其生长条件进行了研究,结果表明,L42菌株的最佳生长条件为20℃,培养24 h,5%接种体积分数,培养基初始pH为8.0,摇瓶装液体积50 mL（250 mL三角瓶）,NaCl质量分数为2%-4%。

Strain L42 with high production of lipase was selected from 127 bacterial strains isolated from seawater and sediments in Lianyungang sea area. Cell of strain L42 was rod-shaped （0.2-0. 5） gm× （1.0-1.5）μm and Gram-negative with polar flagella but no spore forming. Consequently, its optimal growing conditions of shaking flask culture were studies and obtained as follows： 24 h, the initial pH 8. 0, inoculation amount of 4%, aeration of 50 mL/250 mL, 20 ℃ and the concentration of NaCl from 2% to 4 0%.