高寒草地土壤三色小皮伞菌产漆酶特性的研究

以1株三色小皮伞菌（Marasmius tricolor）（编号310b）为供试菌株，采用底物显色法和液体摇瓶发酵法，研究了供试菌株Marasmius tricolor 310b在3种底物（愈创木酚、邻苯二酚和邻苯甲苯胺）选择性培养基上产漆酶的相对酶活力，在愈创木酚-PDA培养基上的相对产酶速度，以愈创木酚为底物催化液体发酵粗酶液的酶活力以及粗酶液酶学性质。结果表明：供试菌株Marasmius tricolor 310b在含有愈创木酚、邻苯二酚和邻苯甲苯胺等3种底物的选择性培养基上能够生长且产生氧化带，在不同底物的选择性培养基上氧化带的颜色、直径以及菌落大小不尽相同，在愈创木酚选择性培养基上产生的氧化带直径和菌落直径最大。愈创木酚能够在供试菌株生长早期诱导菌丝分泌漆酶；以愈创木酚为底物测得菌株液体发酵粗酶液的漆酶活力最高。供试菌株分泌的漆酶在30℃、pH=4.5时酶的催化活性达到最大值，0～45℃、pH 4.0～6.5范围内保持较高的酶活力。

Producing Laccase-characteristics of Marasmius tricolor Isolated from the Soil of Alpine Meadow

A fungus strain belonging to Marasmius tricolor has been isolated and selected from the soil of alpine meadow located in eastern Qilian Mountains. To full understand the characteristics of the fungus producing the laccase, three substrates (i.e., guaiacol, caechol, and o-benzyl aniline) were used to induce the activity of laccase, using substrate spectrophotometry and liquid rotating methods. The temporal order and sizes that the oxidation zones occurred on guaiacol-PDA culture media were analyzed to investigate the relative rates that the fungus produced laccase. The results showed that Marasmius tricolor produced oxidation zones cultured on the media that contained guaiacol, caechol, and o-benzyl aniline, respectively, but the colors and diameter sizes of the oxidation zones and fungus community diameters differed from different media. The diameters of the oxidation zones and fungus community were the greatest when the fungus was cultured on the medium that contained guaiacol. The fungus showed the greatest activity producing laccase. Guaiacol might induce its hypha to secrete laccases at the early stage of its growth. Laccase activity was the highest when guaiacol was substrate in the reaction system. Laccase produced by the fungus showed the greatest activity under the condition of 30℃ and pH 4.5. The enzyme also showed higher activity under the condition of 0~45℃, pH 4.0~6.5.