贝莱斯芽孢杆菌RJW-5-5的分离鉴定及细菌素、抗菌肽基因簇挖掘

【背景】化学防治污染日益严重,作物抗性、农药残留、病害再生现象越来越普遍,因此筛选新型生防菌株及研究其抗菌物质已成为热点。【目的】筛选出一株对禾旋孢腔菌等植物病原菌具有生防功能的贝莱斯芽孢杆菌,挖掘其调控合成细菌素、抗菌肽(RiPPs)的基因簇。【方法】通过分离筛选、对峙培养等方法筛选出菌株,通过全细胞脂肪酸和Biolog分析法以及分子生物学方法进行菌株鉴定。利用Illumina NovaSeq 6000平台进行全基因组序列测定,通过BAGEL4挖掘潜在的细菌素、RiPPs基因簇及潜在的作用机制。【结果】菌株RJW-5-5对禾旋孢腔菌的抑制效果最好,抑制率可达78.4%,对疫霉菌、菊池链格孢等病原菌均有较好的抑制作用,利用NCBI网站的BLAST功能对所测的16S rRNA基因和rpoB基因序列进行同源性分析,鉴定菌株RJW-5-5为贝莱斯芽孢杆菌(Bacillus velezensis)。BAGEL4分析菌株RJW-5-5全基因组序列含有合成Lasso_peptide、Cerecidin、Sactipeptides以及Propionicin_SM1的基因簇,其中Propionicin_SM1为首次在芽孢杆菌属中发现,能够合成双功能蛋白TrpGD、二硫还原酶、2-氧戊二酸脱氢酶E1组分等。【结论】菌株RJW-5-5能够抑制多种农作物病害,具有多种羊毛硫抗生素、套索肽、细菌素等抗菌肽基因簇,具有广阔的发展前景及应用潜力。

Isolation and identification of Bacillus velezensis RJW-5-5 and gene cluster mining of bacteriocin and RiPPs

Background]Chemical control pollution is becoming more and more serious,"3 R"problems are becoming more and more common.Therefore,screening new biocontrol strains and studying their antibacterial substances have become a hot spot.Objective]To screen a strain of Bacillus velezensis that has biocontrol function against phytopathogenic bacteria such as Cochlioboluss ativus,and excavate its gene clusters that regulate the synthesis of bacteriocins and RiPPs(antibacterial peptides synthesized by ribosome pathway).Methods]Strains were screened by methods such as separation and screening,confrontation culture,etc.,and strain identification was performed by whole cell fatty acid,Biolog analysis and molecular biology methods.The Illumina NovaSeq 6000 platform was used to determine the whole genome sequence,and the potential bacteriocins,RiPPs gene clusters and potential mechanisms of action were explored through BAGEL4.Results]Strain RJW-5-5 had the best inhibitory effect on Cochlioboluss ativus,and the inhibition rate reached 78.4%.Strain RJW-5-5 was identified as Bacillus velezensis.Conclusion]Strain RJW-5-5 can inhibit various crop diseases,has a variety of lantibiotic,lasso peptide,bacteriocin and other antibacterial peptide gene clusters,with broad development prospects and application potential.