一株产木聚糖酶嗜热菌的鉴定及酶学性质

Identification of a thermophilic bacterium and preliminary characterization of the secreted xylanase

摘要:

从云南腾冲热泉水样中分离筛选得到一株产木聚糖酶的菌株。通过细菌形态观察、生理生化特性并结合16S rDNA 序列分析, 经鉴定, 该菌为地芽孢杆菌(Geobacillus sp.), 命名为Geobacillus sp. PZH1。对该菌株所产嗜热木聚糖酶及酶学特性进行了初步研究。SDS-PAGE 和酶谱分析测得该酶分子量约为69 kD; 酶的最适反应pH 和最适反应温度分别为7.0 和70 °C, 在pH 5.0?11.0 和40 °C?100 °C 范围内均有较高酶活; 该酶在pH 5.0?12.0 范围内和70 °C 以内具有较高的稳定性; 40 °C?100 °C 范围内, 该木聚糖酶没有被检测到纤维素酶活性。

Abstract:

The bacterium isolated from a water sample of Yunnan tengchong hot spring can secrete a kind of thermophilic xylanase. It was identified and named as Geobacillus sp. PZH1 by morphologic observation, physio-biochemical characteristics and 16S rDNA sequence alignment. Subsequently, its secreted xylanase and the xylanase’s characteristics were researched preliminarily. SDS-PAGE electrophoresis and zymogram analysis suggested that the xylanase’s molecular mass was 69 kD; the optimum pH and temperature of the partially purified enzyme were 7.0 and 70 °C respectively, and it performed noted activities from pH 5.0 to pH 11.0 and from 40 °C to 100 °C; it had high stability from pH 5.0 to pH 12.0 and under 70 °C; from 40 °C to 100 °C, no cellulase activity was detected for the partially purified xylanase.