西印度洋产纤维素酶细菌的筛选及酶学特性初步研究

Screening of cellulase-producing bacteria from the West IndianOcean and preliminary study on its enzymatic properties

本研究从西印度洋表层沉积物中筛选获得1株高抗性、稳定性好的纤维素酶高产菌株XN149,通过形态学、革兰氏染色、生理生化鉴定以及16S rRNA基因序列分析对菌株进行分类鉴定,并研究了其酶学特性。结果表明,菌株XN149为漳州芽孢杆菌(Bacillus zhangzhouensis),具有较高的产纤维素酶能力。酶学特性研究表明,该菌株所产纤维素酶的最适反应温度为65℃,最佳pH为6.0,该条件下发酵48 h后粗酶液酶活力为(60.19±0.31) U/mL。在30~60℃及pH为5.0~8.0时酶活性稳定性较高,Fe3+、Mn2+对该酶活性有一定的促进作用,Ba2+对其酶活性具有抑制作用。综上,漳州芽孢杆菌XN149是一株高产纤维素酶菌株,所产纤维素酶具有良好的耐热性和一定的酸碱耐受性,具有潜在的产业应用开发价值。

In this study,a highly resistant and stable cellulase high yielding strain XN149 was obtained from the surface sediments of West Indian Ocean and the strain was classified by colony morphological characteristics,Gram staining,physiological and biochemical tests and 16S rRNA gene sequence analysis,and its enzymatic properties were investigated.Results showed that strain XN149 was Bacillus zhangzhouensis,which had a high cellulase production capacity,and its enzyme activity of the crude enzyme solution was(60.19±0.31)U/mL after 48 h of fermentation at pH 6.0 and 65℃.The enzymatic properties showed that the optimum reaction temperature for cellulase production was 65℃,and the optimum pH was 6.0,and the stability of enzyme activity was higher at 30-60℃and pH 5.0-8.0.Fe 3+and Mn 2+had a certain promotion effect on the enzyme,and Ba 2+played an inhibitory role on the enzyme activity of the strain.In conclusion,Bacillus zhangzhouensis XN149 is a high cellulase producing strain with good heat resistance and acid-base resistance to a certain extent,which indicates that the strain has potential industrial application and exploiting value.