产耐热β-葡萄糖苷酶细菌的筛选与鉴定

摘要

From 1323 bacteria strains collected by the Culture Collection Center of Industrial Microorganism sin Jiangnan Uninversity (CIC IM-CU ), 20 strains with relatively high capability of producing therm ophilic β-glucosidase were isolated . 5 strains were identified as Geobacillus sp . and the others were identified as B acillus licheniform is by 16s rDN A sequencing analysis . C rude enzym es was characterized from Geobacillus sp . (170-28-2 ) and B acinus licheniform is (F157043A ) . The Geobacillussp . with a specific activity of 0.36 U/m g showed optimal activity at pH 8 .0 and 53℃ and the B acillus licheniform is with a specific activity of 0.66 U /m g show ed optim alactivity at pH 9 .0 and 55℃ . Based on morpholoigcal, physiological and biochem ical properties , the strain of F157043A was further identfied as Bacillus lichen iform is .%从中国高校工业微生物资源和信息中心(CICIM-CU)菌种库的1323株细菌保藏物中筛选出20株产β-葡萄糖苷酶能力较高的细菌.通过16S rDNA序列鉴定,初步确定其中有5株为嗜热溶胞土芽孢杆菌 (Geobacillus sp.),其余为地衣芽孢杆菌 (Bacillus licheniformis).对其中编号为F157043A的地衣芽孢杆菌和编号为170-28-2的嗜热溶胞土芽孢杆菌进行了粗酶液酶学性质分析,发现地衣芽孢杆菌最适反应温度为55 ℃,最适反应pH值为9.0,该条件下测得粗酶液比酶活为0.66 U/mg;嗜热溶胞土芽孢杆菌最适反应温度为53 ℃,最适反应pH值为8.0,该条件下测得粗酶液比酶活为0.36 U/mg.通过菌体和菌落形态观察以及生理生化特征分析,进一步鉴定编号为F157043A的菌株为地衣芽孢杆菌.