高产漆酶真菌菌株的筛选及酶学性质研究

Screening of High-yield Laccase Fungal Strains and Enzymatic Characteristics Study

从6株野生真菌和5株食用真菌中筛选出高产漆酶菌株,并对筛选出的野生菌株漆酶酶学性质进行初步探究。使用G-PDA确定菌株的产漆酶能力,然后通过液体发酵对产生的粗酶液进行酶活力测定,确定高产漆酶菌株,最后分别在不同pH和温度下进行酶学性质探究。初步筛选结果：第7天时,05号菌丝直径最大89.1mm,08号显色圈直径最大76.8mm,04号的显色圈颜色最深,09号显色反应最不明显。对于漆酶活力：04号活力最高262.7U/mL,其次是08号和05号分别为255.3U/mL、203.9U/mL。01和06号酶活力达到最大所需时间最短。酶学性质方面,08号的最适pH是3.2、最适温度是40℃;在不同pH、温度下分别保温2h,pH=4.0酶活力残余率为94.20%;温度在20~40℃内,酶活力残余率在99.00%以上。结果表明,0.04%G-PDA最适作为产漆酶真菌的初筛培养基;高产漆酶能力的菌株有04、05和08号菌株,且08号菌株漆酶的最适应用条件是pH=4.0、温度为40℃。

Object ：Laccase High‐yielding strains are screened from 6 wild fungi and 5 edible fungi .And a preliminary study of laccase enzymatic characteristics of screened wild yield laccase strains .Method：The use of G‐PDA identi‐fied 11 kinds of fungal laccase production capacity .Then ,the crude enzyme solution generated by liquid fermenta‐tion activity ,which was measured ,and got High‐yielding strains of laccase .At last ,Laccase put separately at differ‐ent pH and temperature measurement of enzyme activity . Results：Preliminary screening results ：In the first 7 days ,No .05 mycelium largest diameter is 89 .1mm ,No .08 color‐circle diameter is 76 .8mm ,No .04 color‐circle col‐or is the deepest ,The color reaction No .09 is the most obvious .For laccase activity ：No .04 highest enzyme activity is 262 .7U/mL .Secondly ,No .08 ,No .05 are 255 .3U/mL ,203 .9U/mL respectively .Enzyme activity reached maximum shortest is No .01 and No .06 .In terms of the enzymatic properties ,the optimum pH is 3 .2 ,the optimum temperature is 40℃ of No .08 strain .At pH=4 .0 ,the residual of enzyme activity was 94 .20% ;In the 20~40 ℃ , the lowest rate of residual enzyme activity was 99 .00% .Conclusion：0 .04% G‐PDA as the optimal screening fungal laccase production medium .Strain has the ability to determine the High‐yielding of laccase for No .04 ,No .05 and No .08 strains .And 08 strains of Laccase optimal utilization conditions is pH=4 .0 ,and temperature is 40℃ .