香菇、杏鲍菇与平菇部分胞外酶种类及活性变化规律的对比分析

Type and Activity Variation of Extracellular Enzymes of Lentinus edodes,Pleurotus eryngii and Pleurotus ostreatus

为了比较不同腐生食用菌降解纤维素、木质素以及淀粉的能力,以平菇(Pleurotus ostreatus)、香菇(Lentinus edodes)和杏鲍菇(Pleurotus eryngii)为研究对象,采用平板变色圈法对胞外酶种类进行定性检测,选用36%木屑、43%锯末、20%麸皮、1%蔗糖,58%~60%水分,pH 6.6为栽培基质进行栽培出菇,再利用分光光度计法检测其中4种代表性胞外酶在生长发育各阶段的酶活性变化。结果表明:利用变色圈法在平菇、香菇和杏鲍菇中均检测到羧甲基纤维素钠酶(CMCase)、木质素过氧化物酶(Lignin peroxidase,LiP)、漆酶(Laccase)和锰过氧化物酶(Manganese peroxidase,MnP);在平菇及香菇中检测到淀粉酶(Amylase),在香菇中未检测到淀粉酶。杏鲍菇羧甲基纤维素钠酶、滤纸酶、淀粉酶活性与子实体形成正相关,子实体快速生长或者子实体成熟时活性峰值,在发菌及潮菇间期酶活性低;漆酶活性在发菌期有较高的水平,在菇蕾形成达到第一个活性高峰,随后逐渐下降直到子实体老化阶段酶活性升高到第二个高峰;表明杏鲍菇利用木质素先于纤维素和淀粉。平菇羧甲基纤维素钠酶、漆酶活性与子实体形成正相关,其活性峰分别出现在子实体快速生长及成熟阶段;滤纸酶及淀粉酶在整个生长发育阶段均维持价低水平,子实体形成过程无严格相关性。香菇羧甲基纤维素钠酶、滤纸酶在发菌阶段酶活性较高,在幼菇阶段达到峰值,之后逐渐下降;淀粉酶活性与子实体形成过程无严格相关性,始终维持在较低水平;在生长发育过程中几乎检测不到漆酶活性。在生长发育过程中,同种菌不同胞外酶之间、相同胞外酶在不同菌之间酶活性大小及变化规律存在一定的差异。

To compare the degradation ability of cellulose, lignin and starch with different saprophytic edible fungi,Pleurotus ostreatus, Lentinus edodes and Pleurotus eryngii were used as representative. Several discolored halo tests were used for qualitative detection of the related extracellular enzymes. The fruiting tests were carried out in a matrix consisting of 36% wood slag,43% sawdust, 20 % bran, 1 % sucrose, 58%--60% moisture, pH 6.6. The activity variations of four representative extraeellular enzymes in the process of mycelium vegetative growth and fruiting body development were detected by spectrophotometer. The results showed that based on discolored halo tests, Lignin peroxidase （LIP）, Laccase and Manganese peroxidase （MnP） were detected in P. ostreatus, L. edodes and P. eryngii; amylase was detected in P. ostreaeus and P. eryngii except in L. edodes. In the process of mycelium vegetative growth and fruiting body development, the activity variations of different types of extracellular enzymes were different in the same mushroom strain, while activity variation for a specific enzyme varied among different mushroom species. For P. eryngii, the activities of CMCase,FPase and amylase were positively correlated with the development of fruiting bodies, and the peaks of enzyme activity appeared in the phase of rapid growth of fruiting body or fruiting body maturity. The activity of laccase reached a relatively high level in mycelium vegetative growth phase, reached a peak in the phase of primordial formation, then decreased gradually from the phase of the young fruiting body to fruiting body maturity, finally it reached another peak in the phase of fruiting body aging. According to the enzymatic activity, it speculated that P. eryngii preferentially degrades lignin, not cellulose or starch in matrix. For P. ostreatus, CMCase and laccase activities were positively correlated with the process of fruiting body development, and their activities peaks appeared in the phase of fruiting body rapidly growth and fruiting body maturity respectively. FPase and amylase activities maintained a low level at all phases. For L. edodes, the activities of CMCase and FPase were maintained a relatively high level in the phase of mycelial vegetative growth,the activities peaks appeared in the early phase of the young mushroom, then decreased gradually. The activity of amylase was not closely related to the formation of fruiting body and remained at a low level. Laccase activity was almost undetectable at all phases.