1株大熊猫肠道纤维素降解菌的分离鉴定及其酶学性质

摘要

Using sodium carboxymethylcellulose as unique carbon source and Congo red staining method,cellulose degradable bacterial strains were isolated from giant panda's fecal samples,and studied on their enzymatic characteris-tics. Strain A1 with high enzyme activity was isolated,it was identified as Bacillus cereus morphologically and through BD PhoenixTM-100 full-automatic bacteria identification instrument. Growth condition and enzymatic activity tests showed that the optimal growth temperature of the strain was 37 ℃. 0. 5%NaCl and pH at 7. 0 the maximum activity of endo-glucanase was at 0. 139 IU/mL,exo-glucanase 0. 074 IU/mL,beta-glucosidase 0. 126 IU/mL and the total ernzymatic activity was 0. 108 5 IU/mL respectively. This research enriched the species of cellulose degrading-bacteri-a in giant panda's intestines and strain A1 provided strain source for the following up study on how the giant panda di-gest and utilize bamboo fiber.%以羧甲基纤维素钠为唯一碳源，利用刚果红染色法，从大熊猫粪便内筛选具有降解纤维素能力的菌株，并研究其酶学特性。分离获得1株酶活力较高的菌株A1，通过形态学和BD PhoenixTM-100全自动细菌鉴定仪鉴定为蜡样芽胞杆菌（ Bacillus cereus）。菌株A1最适生长条件和酶活力测定表明，其最适生长温度为37℃，NaCl浓度为0.5%，pH值为7.0，内切葡聚糖苷酶、外切葡聚糖苷酶、β-葡萄糖苷酶和总酶活的最大值分别为0.139、0.074、0.126、0.1085 IU/mL。丰富了大熊猫肠道纤维素降解菌的种类，为后续研究大熊猫如何消化利用竹纤维提供了菌源。