白蚁肠道内纤维素酶产生菌的筛选及其酶活性

从黑翅土白蚁(Odontotermes formosanus Shiraki)肠道内筛选具有纤维素降解能力的细菌,并研究其酶活性。结果表明:筛选得到5株菌株,活力较高的菌株CMC-4被鉴定为土白蚁特拉布尔希氏菌Z-4(Trabulsiella odontotermitis ZJSRU-4)。同时对菌株T.odontotermitis ZJSRU-4进行了系统的研究,它具有完整的纤维素酶系统,主要产羧甲基纤维素酶(CMCase)和β-葡萄糖苷酶,滤纸酶的活力较低。在以羧甲基纤维素钠为碳源的培养基中培养36 h,发酵液中CMCase的比酶活达到20.8 U/m L,培养44 h,β-糖苷酶的比酶活达到18.2 U/m L。CMCase和β-葡萄糖苷酶作用的p H分别为6.0和6.5,它们作用的最适温度都为40℃。该菌对纤维质原料具有降解能力,具有潜在的应用价值。

Isolation of cellulose-degrading strains from the gut of termites and characterization of its cellulase-producing capability

Five mesophilic bacteria with cellulose-degrading ability were isolated from the gut of termites （ Odontotermes formosanus Shiraki） . Strain CMC-4 with high cellulose-degrading ability was identified as Trabulsiella odontotermitis ZJSRU-4 according to physiological tests and phylogenetic analysis-High carboxymethyl cellulase（ CMCase） and β-glucosidase activity was detected,and filter paper activity was also produced at a low level. When sodium carboxymethyl cellulose was used as carbon source,CMCase activity reached 20-8 U/mL at 36 h and β-glucosidase activity 18-2 U/mL at 44 h. Maximum CMCase activity was at pH 6-5,40℃,while maximumβ-glucosidase activity was at pH 6-0,40℃-This strain has potential industrial application to produce cellulose.