从温泉热源地区采集的大量泥土和水样中,筛选出一株在60℃生长的纤维素酶产生菌SH2。结合菌株的生理生化特性分析与Biolog微生物自动鉴定仪的鉴定结果,命名为热葡糖苷酶地芽孢杆菌(Geobacillus thermoglucosidasius)SH2,该菌株兼性好氧,在45~60℃能较好地生长。对菌体生长与产酶培养条件优化表明:初始pH值为5.5,碳、氮源分别为蔗糖和玉米浆时有利于产酶,经48h发酵后纤维素酶酶活达0.36IU/mL。纤维素酶反应条件研究表明,该纤维素酶的最适pH值为6.0,在pH4.0~10.0范围具有较强的耐受性;在45~65℃间酶活差异仅在5%之内,显示了很好的温度耐受性。
A thermophilic strain SH2 possessing cellulase was isolated at 60℃ from hot-spring samples of east China coast. Based on the analysis of morphology and some biochemical and physiological characteristics, strain SH2 was identified as Geobacillus thermoglucosidasius combined with the analysis of Biolog Microstation Identification System. It was facultative aerobe. Strain SH2 was capable of growing well on 45 ℃-60 ℃. According to optimization condition of cell growth and enzyme production, the initial pH is 5.5. The supernatant of strain incubated medium showed efficient activity of cellulase with addition of sucrose and corn steep as carbon and nitrogen sources respectively. The highest enzyme was activity at reached 0. 36 IU/ mL after incubation for 48h. The optimal pH of the celullase for the reaction is 6.0. This enzyme shows stable active over a broad range of temperature from 45 ℃ to 65 ℃. These characteristics of the cellulase demonstrated that it's potential application in thermostable cellulase needed industry.