附子白绢病菌拮抗菌的鉴定、发酵条件优化及抑菌效果  

Identification,fermentation condition optimization,and effect of a strain against Sclerotium rolfsii in Aconitum carmichaeli

作　　者：汤永玉 吴国星[1] 朱国渊 李冉 施春兰 王思洁 杨燕通 高熹[1] TANG Yongyu;WU Guoxing;ZHU Guoyuan;LI Ran;SHI Chunlan;WANG Sijie;YANG Yantong;GAO Xi(College of Plant Protection,Yunnan Agricultural University,Kunming 650201,Yunnan,China)

机构地区：[1]云南农业大学植物保护学院,云南昆明650201

出　　处：《微生物学通报》2023年第7期2892-2906,共15页Microbiology China

基　　金：四川省区域创新合作项目(2021YFQ0022);云南省中青年学术和技术带头人后备人才项目(202205AC160077)。

摘　　要：【背景】附子白绢病是由齐整小核菌(Sclerotiumrolfsii)引起的一种土传细菌性病害,该病原菌严重影响附子的生产。【目的】筛选出对附子白绢病具有生防效果的菌株,并将其用于病害防治。【方法】利用平板涂布法和划线法从黄粉虫蛹体分离菌株,平板对峙法筛选对齐整小核菌具有较强拮抗能力的菌株,通过形态学观察、生理生化试验、16S rRNA基因测序分析确定其分类地位;以单因素试验对发酵条件进行优化,并初步测定拮抗菌的菌悬液、挥发性气体和发酵液对齐整小核菌菌丝的抑制效果。【结果】筛选出的拮抗菌株将其编号为N2,初步鉴定为暹罗芽孢杆菌(Bacillus siamensis);菌株N2最佳培养基配方(g/L):胰蛋白胨10.0,酵母浸粉5.0,蔗糖20.0;最佳培养条件:初始pH 6.0,温度36℃,转速240 r/min,装液量30 mL,接菌量0.05%;其菌悬液、挥发性气体和发酵液均能有效抑制白绢病菌菌丝的生长;胞外酶测定结果显示该菌株可产生蛋白酶和纤维素酶,不产嗜铁素。【结论】菌株N2对附子白绢病具有较好的抑制效果,在生物防治中具有较好的应用潜力和较高的研究价值。[Background]Southern blight of Aconitum carmichaeli is a soil-borne bacterial disease caused by Sclerotium rolfsii,which seriously affects the production of the medicinal plant.[Objective]To screen a strain against the S.rolfsii in A.carmichaeli and use it for disease control.[Methods]The strains were isolated from Tenebrio molitor pupae by plate coating method and streak plate method.The strain with strong ability against S.rolfsii was identified by plate confrontation assay,and the taxonomic status was determined based on morphological observation,physiological and biochemical tests,and 16S rRNA sequencing.Fermentation conditions were optimized by single factor test.The inhibitory effect of suspension,volatile gas,and fermentation broth of the antagonistic strain on the mycelia of S.rolfsii was determined.[Results]An efficient antagonistic strain N2 was screened out and identified as Bacillus siamensis.The best medium formula(g/L)of strain N2 is tryptone 10.0,yeast extract 5.0 and sucrose 20.0.The optimum culture conditions were as follows:initial pH 6.0,temperature 36℃,rotating speed 240 r/min,liquid volume 30 mL,and inoculum 0.05%.The suspension,volatile gas,and fermentation broth of the strain all can effectively inhibit the growth of S.rolfsii mycelia.The results of extracellular enzyme assay showed that the strain could produce protease and cellulase but failed to synthesize siderophore.[Conclusion]Strain N2 has ideal inhibitory effect on S.rolfsii of A.carmichaeli,which has a good application potential and high research value in biological control.

关 键 词：附子白绢病 暹罗芽孢杆菌 发酵条件优化 抑制效果 生物防治 

分 类 号：S435.672[农业科学—农业昆虫与害虫防治]