野生茯苓鉴定及其木质纤维素降解酶系研究
为揭示茯苓木质纤维素降解酶系及培养方式对其主要酶系的影响，该研究测定了茯苓主要木质纤维素降解酶系。首先对野生茯苓菌株进行培养特性的显微观察；再利用3 对引物PCR 扩增进行系统发育学的鉴定；经定性培养筛选出优势菌株YX1，最后采用酶标仪测定不同条件下纤维素酶、半纤维素酶和木质素降解酶的活力大小。结果表明:（1）茯苓有菌丝体、子实体和菌核3 种形态特征。（2）PCR 分别获得rDNA-ITS序列1 652 bp、核糖体大亚基序列660 bp 和翻译延伸因子序列545 bp，提交至NCBI，登录号分别为ON129554、ON129553 和ON155840。（3）纤维素酶和半纤维素酶在有/无松木屑条件下，外切β-葡聚糖酶(CBH)、内切β-葡聚糖酶(EG)和β-葡萄糖苷酶(BGL)最高分泌量分别为16 ~ 17、32 ~ 35、36 ~ 37 U•mL-1；木聚糖酶、甘露聚糖酶和α-葡萄糖苷酶最高分泌量分别为28 ~ 38、280 ~ 342、9 ~ 11 U•mL-1；锰过氧化物酶(MnP)、漆酶(Laccase)、木素过氧化物酶(LiP)这3 种木质素降解酶在4 种不同培养液中都有微弱的酶活性。综上表明，该研究结合形态学与分子鉴定，明确了野生茯苓YX1 的分类地位，与褐腐菌在亲缘关系上既有联系又存在遗传差距，测定结果显示木质纤维素酶中的酶活大小依次为甘露聚糖酶>木聚糖酶>BGL>EG>CBH>α-葡萄糖苷酶>LiP>MnP>Laccase，纤维素酶和半纤维素酶酶活之间存在显著差异(P<0.05)，本研究为茯苓产生木质纤维素降解酶系的降解机制提供了基础酶学参考。
微生物学生物化学
茯苓，ITS 序列，纤维素酶，半纤维素酶，木质素降解酶
覃雯,胡婷,黄祝,胡雅楠,尹立伟,杨春成,武琳.野生茯苓鉴定及其木质纤维素降解酶系研究[EB/OL].(2022-09-03)[2025-10-16].https://chinaxiv.org/abs/202209.00013.点此复制
In order to reveal the effects of Wolfiporia cocos lignocellulolytic enzymes and culture methods on itsmain enzymes, the main lignocellulolytic enzymes of W.cocos were determined in this study. Firstly, themicroscopic observation of the culture characteristics of the wild W. cocos strains was carried out; then three pairsof primers were used for PCR amplification to carry out phylogenetic identification; The dominant strain YX1was screened by qualitative culture and finally the activities of cellulase, hemicellulase and ligninolytic enzymesunder different conditions were determined by microplate reader. The results were as follows: 1 Threemorphological characteristics: mycelium, fruiting body and sclerotium of W. cocos;2PCR obtained rDNA-ITSsequence of 1 652 bp, ribosomal large subunit sequence of 660 bp and translation elongation factor sequence of545 bp, and submitted to NCBIaccession numbers are ON129554, ON129553, and ON155840, respectively;3The highest secretion of exo--glucanase(CBH), endo--glucanase(EG) and -glucosidase(BGL) in the presenceor absence of sawdust was 16 - 17, 32 - 35, 36 - 37 UmL-1The maximum secretion of xylanase, mannanase and-glucosidase was 28 - 38, 280 - 342, 9 - 11 UmL-1.The three ligninolytic enzymes Manganese peroxidase (MnP),Laccase (Laccase), and Lignin peroxidase (LiP) had weak enzymatic activities in four different cultures. Inconclusion, this study combines morphological and molecular identification to clarify the taxonomic status ofYX1, which has both a relationship and a genetic gap with brown rot fungi.The results finally showed that themagnitude of enzymatic activities in lignocellulases were in the order of mannanase > xylanase > BGL> EG >CBH > -glucosidase > LiP > MnP > Laccase, and there were significant differences between cellulase andhemicellulase enzymatic activities (P<0.05). This study provides a basic enzymatic reference for the degradationmechanism of the lignocellulolytic enzymes system produced by W.cocos.
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