一株高寒地区产纤维酶细菌的筛选、鉴定及酶学性质研究

Isolation, identification and characterization of a cellulase-producing strain from alpine region

从青海茶卡盐湖地区土壤中分离出一株产纤维素酶的细菌菌株，根据菌落形态特征以及16SrDNA序列分析，初步鉴定为琼斯氏菌属（Jonesia quinghaiensis sp．）。在25℃、初始pH值为7．0的发酵条件下，该菌株产酶量培养45h达到最大值，发酵液酶活力为0.3U／mL。酶学性质研究表明，该纤维素酶最适反应pH值为8．0，最适反应温度为35℃，在30-40℃的范围内保持60％Hi~性。金属离子Mn^2＋、Co^2＋和Cu^2＋对酶活力有较强的抑制作用，Ca^2＋具有显著的促进催化作用。

A cellulose producing strain was isolated from the soil of Caka Salt Lake. According to the colony morphology and 16S rDNA analysis, the strain was identified as Jonesia quinghaiensis sp. The optimized enzyme production condition was time 45 h, temperature 25 ℃ and initial pH 7.0. At the optimized condition; the maximum cellulase activity was 0.3 U/ml. Enzymatic property analyses demonstrated that the enzyme was the most active at pH 8.0 with temperature 35 %. At the temperature of 30-40 %, the CMCase activity could keep at more than 60%. The addition of Mn^2＋,Co^2＋,Cu^2＋ strongly inhibited CMCase activity, however, Ca2. could strongly stimulate the enzyme reaction.