1株高效降解纤维素的槲寄生内生真菌研究

利用刚果红-CMC平板染色法、DNS法从槲寄生内生真菌中筛选获得1株高效纤维素酶产生菌H-3-3,通过分析其菌落形态特征和18S rDNA序列的同源性,将菌株H-3-3鉴定为拟茎点霉属Phom opsissp.;对其酶学性质研究得到：槲寄生内生真菌H-3-3中CMC酶、β-葡糖苷酶、滤纸酶这3种组分酶最适温度均为50℃,β-葡糖苷酶活和滤纸酶活最适pH值均为4.8,CMC酶最适pH值为4.4;3种酶在30～45℃,pH4.0～8.0稳定性较强。金属离子Mn^2＋、Co^2＋、Mg^2＋和Ca^2＋对3组分酶都有不同程度的促进作用,其中以Co^2＋效果最佳;而Ba^2＋、Zn^2＋、Cu^2＋对3组分酶分均表现出明显的抑制作用。

High Effective Cellulose-Degrading Endophytic Fungus from Mistletoe

An endophytic fungus H-3-3 contained high effective cellulase was screened from mistletoe using Congo red-CMC plate staining and DNS method. Through analysis its colony morphological characteristics and the homology of 18S rDNA sequence the strain was characterized as Phomopsis sp. The enzymology properties of the cellulase were also studied. The results showed that carboxymethylcellulase (CMCase), β-glucosidase and filter paperase (FPase) activities were optimum at 50 ℃, and pH values of 4.4, 4.8 and 4.8 respectively. The enzyme activity was fairly stable at 30～45 ℃ and pH 4.0～8.0. The enzyme activity was promoted by Mn~(2+), Co~(2+), Mg~(2+) and Ca~(2+), inhibited by Ba~(2+), Zn~(2+) and Cu~(2+).