斑须蝽肠道菌的分离鉴定及产纤维素酶菌株的筛选与酶活力测定  

Screening and enzyme activity determination of cellulase-producing strains from the gut bacteria of Dolycoris baccarum L.

作　　者：王琪[1] 陈芳敏 陈广青 夏琬婷 刘宁[1] 游博 朱海[1] WANG Qi;CHEN Fangmin;CHEN Guangqing;XIA Wanting;LIU Ning;YOU Bo;ZHU Hai(Liaoning Key Laboratory of Urban Integrated Pest Management and Ecological Security,College of Life Science and Bioengineering,Shenyang University,Shenyang 110044,Liaoning,China;Key Laboratory of Eco-restoration of Regional Contaminated Environment,Ministry of Education,Shenyang University,Shenyang 110044,Liaoning,China)

机构地区：[1]沈阳大学、生命科学与工程学院、辽宁省城市有害生物治理与生态安全重点实验室,辽宁沈阳110044 [2]沈阳大学区域污染环境生态修复教育部重点实验室,辽宁沈阳110044

出　　处：《微生物学通报》2024年第9期3497-3509,共13页Microbiology China

基　　金：国家自然科学基金(42177406);辽宁省自然科学基金(2023-MS-319)。

摘　　要：【背景】斑须蝽(Dolycoris baccarum L.)是危害高粱、玉米、大豆等多种作物及果树的植食性害虫,其肠道菌的研究对斑须蝽的防治和肠道功能菌资源的挖掘都十分必要。【目的】了解斑须蝽成虫肠道可培养细菌的组成,筛选出产纤维素酶功能菌株,并检测其酶活性,对部分菌株的产酶条件进行初步探究。【方法】采用传统细菌分离培养法获得斑须蝽肠道菌,结合形态学以及16S rRNA基因序列分析进行鉴定;水解圈法筛选纤维素降解菌,利用3,5-二硝基水杨酸(dinitrosalicylic acid,DNS)法测定菌株产纤维素酶活力。【结果】从斑须蝽肠道中共分离出35株菌,可归为5属10种,其中肠球菌属(Enterococcus)3种,芽孢杆菌属(Bacillus)4种,乳球菌属(Lactococcus)、沙雷氏菌属(Serratia)与泛菌属(Pantoea)各1种。筛选出13株具有产纤维素酶功能的菌株,菌株B8、B22、B23和B25产纤维素酶能力较强,其中沙福芽孢杆菌(Bacillus safensis)B22的产酶能力最为突出(D/d=7.01)。酶活力测定结果显示,在实验设定的梯度范围内,发酵培养基pH为5.0,菌株B8、B23和B25培养24 h、菌株B22培养36 h时产酶活力最强。【结论】斑须蝽肠道可培养菌资源丰富,分离获得的肠道菌中具有产纤维素酶功能的菌株高达37%,可协助食物消化影响宿主健康。发酵时间与发酵培养基pH均影响功能菌株的产纤维素酶活性,菌株B22具有较强的产酶能力可进一步开发利用。[Background]Dolycoris baccarum L.is a herbivorous pest that harms sorghum,maize,soybean and other crops and fruit plants.Studying its gut bacteria is essential for the control of D.baccarum L.and the exploration of functional bacterial resources from the gut.[Objective]This study aims to gain insights into the culturable bacteria in the gut of D.baccarum L.and screen out cellulase-producing strains.The cellulase activities of the strains screened out were determined.The enzyme production conditions of several strains were explored.[Methods]The gut bacteria of D.baccarum L.were isolated by the culture method and identified by morphological observation and 16S rRNA gene sequencing.The inhibition zone method was employed to screen out the strains capable of producing cellulase.The cellulase activities of the strains were determined by the 3,5-dinitrosalicylic acid(DNS)method.[Results]A total of 35 strains were isolated from the gut of D.baccarum L.,they are 10 species of bacteria belonging to 5 genera,including 3 species of Enterococcus,4 species of Bacillus,and 1 species of Lactococcus,Serratia,and Pantoea,respectively.A total of 13 strains capable of producing cellulase were screened out.Strains B8,B22,B23,and B25 had strong cellulase-producing capacity,among which B22 had the most prominent cellulase-producing ability(D/d=7.01).The cellulase-producing capacity was the strongest in the medium with pH 5.0,culture with B8,B23,and B25 for 24 h,or culture with B22 for 36 h.[Conclusion]The gut of D.baccarum L.harbors rich culturable bacteria and 37%of the isolates can produce cellulose,which can assist in food digestion and influence the host health.Both fermentation time and medium pH influence the cellulase production of functional strains.Strain B22 with strong cellulase-producing ability should be further developed and utilized.

关 键 词：斑须蝽 肠道菌分离鉴定 产纤维素酶功能菌 纤维素酶活性 

分 类 号：S433.3[农业科学—农业昆虫与害虫防治]