几丁质酶产生菌筛选鉴定及产酶性能研究

Research on Screening ,Identification and Enzyme Producing Characteristics of Chitinase Producer

从土壤样品中筛选得到一株高产几丁质酶菌株C65-2,经形态学观察和18S rDNA序列测定,鉴定为Aspergillus fumigatus,对产酶培养基进行初步优化,测得最高酶活可达6.9U/ml,酶活力较优化之前提高了210%。酶学性质研究表明该几丁质酶分子量约为20kDa,酶在60℃下保温50min酶活降为0,最适酶反应温度是55℃,酶反应最适pH为7.0,Mg2+,Cu2+对酶反应有促进作用,Fe3+对酶反应有抑制作用。

C65-2 strain with high chitinase producing ability was isolated from soil and identified it as Aspergillus fumigatus by observing its morphology character and measuring its 18S rDNA sequence. The chitinase producing conditions was optimized. The maximum activity could be up to 6.9 U/ml and the enzyme activity increased 210% than before. The study of enzymatic properties of the chitinase showed that the molecular weight was 20kDa. Thermostable stability of the chitinase was not good and the enzyme activity reduced to 0 at 60℃ for 50 min. The optimal enzyme reaction temperature was 55℃ and the optimal pH of enzyme reaction was 7.0. The chitinase activity can be enhanced by Mg2＋ ,Cu2＋ and inhibited by Fe3＋.