【摘要】 从取自华中农业大学的土样和长江流域及桂林桃花江水样中筛选到一株产低温脂肪酶的适冷菌,初步鉴定为假单胞菌,命名为Pseudomonas sp.YT34-8。对其产酶条件进行优化,得到其最佳发酵条件为:玉米浆2.00%,豆饼粉2.50%,蔗糖1.00%,橄榄油0.57%,MgSO4.7H2O 0.05%,K2HPO4 0.10%,发酵温度8℃,初始pH值7.0,发酵时间48 h,250 mL摇瓶装液量21 mL;摇瓶转速182 r.min-1。在此条件下,其发酵酶活力可达到7.833 U.mL-1。对其所产低温脂肪酶进行初步研究,其最适作用pH值为8.0,最适作用温度为30℃,在pH值5.0～10.0范围内、40℃以下酶活力较稳定。更多还原

【Abstract】 A psychrotrophic Pseudomonas sp.strain that produced low-temperature lipase was isolated from soil and water which were taken in Huazhong Agricultural University.The strain was identified and named as Pseudomonas sp.YT34-8.The optimal lipase-producing conditions of the strain was as follows: 2% corn steep liquor,2.5% soybean flour,2.5% Sucrose,1% olive oil,0.05% MgSO4·7H2O,0.1% K2HPO4,pH 7.0,8℃,the culture period of 48h,21ml fermenting liquor in 250 ml flask,and the shaking frequence of 182 r·min-1.The highest production of low-temperature lipase was 7.833 U·mL-1.The lipase was stable at pH 5.0～10.0 and under 40℃,with optimal pH and temperature for enzymatic reaction were pH 8.0 and 30℃.更多还原