云南松毛虫肠道真菌的分离鉴定及降解纤维素真菌的筛选  

Isolation and identification of intestinal fungus and screening of cellulolytic fungus in Dendrolimus houi(Lepidoptera:Lasiocampidae)

作　　者：江宇航 蔡赛波 李宏伟 林连兵[1,2] 张棋麟 JIANG Yuhang;CAI Saibo;LI Hongwei;LIN Lianbing;ZHANG Qilin(College of Life Science and Technology,Kunming University of Science and Technology,Kunming 650500,China;Engineering Research Center for Replacement Technology of Feed Antibiotics of Yunnan College,Kunming 650500,China)

机构地区：[1]昆明理工大学生命科学与技术学院,昆明650500 [2]云南省高校饲用抗生素替代技术工程研究中心,昆明650500

出　　处：《应用与环境生物学报》2020年第6期1437-1442,共6页Chinese Journal of Applied and Environmental Biology

基　　金：国家自然科学基金项目(31960286,31760042)资助。

摘　　要：为明确云南松毛虫肠道内可培养真菌的组成,筛选出具有降解纤维素性能的肠道真菌,采用传统真菌培养方法结合ITS扩增子测序对云南松毛虫幼虫肠道内的可培养真菌进行鉴定.然后利用刚果红染色法筛选出具有一定降解纤维素能力的真菌,使用二硝基水杨酸(DNS)法测定不同pH(5.0-9.0)下降解羧甲基纤维素酶的活性.结果发现:云南松毛虫肠道内真菌菌群多样,并从中筛选到根霉属(Rhizopus)、Cystobasidium、Trichaptum、Hypocreales、曲霉菌属(Aspergillu)、镰孢菌属(Fusarium)、青霉菌属(Penicillium)、念珠菌属(Candida)等3门8属的真菌,其中具有降解纤维素能力的2株为链状假丝酵母(Candida catenulate)和桔青霉(Penicillium citrinum).酶活力测定结果显示:2株降解羧甲基纤维素的真菌在pH=6.0-8.0之间均有相对较高的酶活性,在pH=7.0达到最高.本研究表明云南松毛虫幼虫肠道真菌种类多样,存在具有降解纤维素能力的真菌菌株,其酶活力在中性条件时最高,偏酸性条件下的羧甲基纤维素酶活性显著高于偏碱性条件下;获得的降解纤维素真菌可为饲料生产、食品加工、化学能源等提供有价值的菌种资源.(图4表5参31)The goal of this study was to determine the composition of culturable fungi in the intestinal tract of Dendrolimus houi,and to thereby screen for intestinal fungi capable of degrading cellulose.In this study,the culturable fungi in the intestinal tract of D.houi larvae were identified using a traditional fungal culture method combined with ITS amplicon sequencing.Subsequently,the cellulose-degrading fungus was screened using Congo red staining,and the activity of the carboxymethyl cellulose degrading enzyme was determined using the dinitrosalicylic acid(DNS)method at different pH values(5.0-9.0).Fungi inhabiting the intestinal tract of D.houi were diverse;we screened eight genera belonging to three phyla,including Rhizopus,Cystobasidium,Trichaptum,Hypocreales,Aspergillus,Fusarium,Penicillium,and Candida.Among them,we identified Candida catenulate and Penicillium citrinum as two species with the ability to degrade cellulose.The results of the enzyme activity test showed that these two fungi had relatively high carboxymethyl cellulose degrading enzyme activity at pH=6.0-8.0,reaching the highest level at pH=7.0.The enzyme activity was the highest under neutral conditions,and the carboxymethyl cellulose activity was significantly higher in acidic than in alkaline conditions.The cellulose-degrading fungus species identified in this study could provide valuable fungal resources for feed production,food processing,and chemical energy.

关 键 词：云南松毛虫 可培养肠道真菌 菌种鉴定 纤维素降解 羧甲基纤维素酶 

分 类 号：S763.421[农业科学—森林保护学]