中高温大曲中一株耐热地衣芽孢杆菌耐受性及产酶特性的初步研究

Preliminary study of tolerance and enzyme production characteristics of thermoduric Bacillus Licheniformis strain in medium/high temperature Daqu

以中高温大曲中分离得到的一株耐热地衣芽孢杆菌为出发菌株,通过对地衣芽孢杆菌进行耐受性分析,发现其耐盐、耐pH能力较强;能耐14%的盐浓度,能耐pH范围为pH3.0～10.5;耐乙醇能力较弱,不能耐6%的乙醇浓度;耐温度能力较好,最高能耐55℃的高温。通过3种酶鉴定培养基对地衣芽孢杆菌产淀粉酶、蛋白酶和纤维素酶的能力进行定性鉴定,发现在3种酶鉴定培养基上均能形成透明圈。通过对地衣芽孢杆菌的产酶特性研究发现,在液态培养条件下,地衣芽孢杆菌产淀粉酶和蛋白酶的最适时间均为36 h,最适产酶温度分别为45、40℃,最适产酶转速均为240 r/min;地衣芽孢杆菌产FPA酶和CMC酶的最适产酶时间分别为36、48 h,最适产酶温度均为30℃,最适产酶转速分别为120、90 r/min。

One thermoduric Bacillus Licheniformis strain separated from medium/high temperature Daqu was taken as the original strain. According to the analysis results of its tolerance, it had relatively strong salt tolerance（14% of salt concentration） and pH tolerance（pH range of 3.0～10.5）, relatively weak ethanol tolerance（failed to 6% ethanol concentration）, and relatively good temperature tolerance（resistant to temperatures up to 55 ℃）. After the qualitative identification of production ability of amylase, protease and cellulose of the Bacillus Licheniformis strain, it was found out that it could form transparent zones in the three kinds of mediums. According to the enzyme production characteristics of bacillus licheniformis, the optimal time for the production of amylase and protease of the Bacillus Licheniformis strain was 36 h and the optimal temperature was 45 ℃ and 40 ℃ respectively, the optimal enzyme production speed was 240 r/min under liquid culture conditions. Besides, the optimal time for the production of FPA and CMC of the Bacillus Licheniformis strain was 36 h and 48 h, the optimal temperature was 30 ℃, the optimal enzyme production speed was 120 r/min and 90 r/min respectively under liquid culture conditions.