纤维素降解木霉菌株的筛选及其生物学特性探究  

Screening and biological characteristics of cellulose degrading Trichoderma strains

作　　者：李婉云 杨静雅 赵爽 李敏 赵丽莉[1] 贺学礼[1] LI Wanyun;YANG Jingya;ZHAO Shuang;LI Min;ZHAO Lili;HE Xueli(College of Life Sciences,Hebei University,Baoding 071002,China)

机构地区：[1]河北大学生命科学学院,河北保定071002

出　　处：《河北大学学报（自然科学版）》2021年第6期698-708,共11页Journal of Hebei University(Natural Science Edition)

基　　金：国家自然科学基金资助项目(31470533);河北省研究生创新资助项目(CXZZBS2020021)。

摘　　要：选取分离自河北安国中药材种植基地不同药用植物根区土壤的7株木霉菌,通过羧甲基纤维素钠培养基初筛及玉米秸秆、甘草药渣固态发酵培养基复筛,联合筛选纤维素降解木霉菌株,采用形态学和分子生物学相结合方法进行菌株鉴定,并对其生物学特性进行探究.结果表明,经羧甲基纤维素钠培养基初筛,有4株菌表现出纤维素降解能力,分别为HQ1、BB1、DS3和DS1.经2种木质纤维素底物固态发酵培养基复筛发现,BB1以玉米秸秆为发酵基质时滤纸纤维素酶(filter paper cellulase,FPase)活性最高,HQ1以甘草药渣为基质时FPase活性最高.结合菌落形态、显微结构和DNA分子鉴定,HQ1被鉴定为长枝木霉(Trichoderma longibrachiatum),BB1为非洲哈茨木霉(Trichoderma afroharzianum).2株菌生物学特性存在趋同性,适宜生长产孢pH为5~6,适宜培养温度为28~33℃,且都表现出抵御干旱胁迫的能力.变差分解表明,不同培养条件对木霉菌生长速率及产孢有重要影响.本实验可为后续进一步优化HQ1和BB1降解不同木质纤维素底物固态发酵培养条件提供依据.We selected 7 strains of Trichoderma spp.from the rhizosphericsoil of medicinal plants in Anguo,Hebei Province,China.The cellulolytic Trichoderma strains were screened by sodium carboxymethyl cellulose medium and solid state fermentation(SSF)medium of corn straw and liquorice residues.Morphological and molecular biological methods were used to identify the strains.And its biological characteristics were investigated.The results showed that after the preliminary screening of sodium carboxymethyl cellulose medium,four Trichoderma strains had cellulose degradation ability,which were HQ1,BB1,DS3 and DS1.The results of SSF showed that BB1 and HQ1 display the highest FPase activity when using corn straw and liquorice residues as fermentation substrate,respectively.Combining colony morphology,microscopic structure and DNA molecular identification,HQ1 and BB1 were-identified as Trichoderma longibrachiatum and Trichoderma afroharzianum,respectively.The biological characteristics of the two Trichoderma strains were similar.The suitable culture pH was 5~6,and the suitable culture temperature was 28~33℃.Both Trichoderma strains showed the ability to resist mild drought stress.The variation partitioning indicated that different culture conditions had important influence on the growth rate and sporulation of Trichoderma strains.This experiment can provide a basis for further optimization of fermentation conditions for HQ1 and BB1 degraded different lignocellulosic substrates using SSF.

关 键 词：药用植物 纤维素降解菌 非洲哈茨木霉 长枝木霉 生物学特性 

分 类 号：Q939.9[生物学—微生物学]