生防菌贝莱斯芽孢杆菌MC2-1全基因组测序分析

【目的】分析贝莱斯芽孢杆菌MC2-1的全基因组序列信息，挖掘该菌株拮抗物质合成的相关基因，为其生防机理研究和开发应用提供数据基础。【方法】采用二代Illumina Hiseq与三代Pacbio平台相结合的测序技术，对从美洲大蠊肠道内分离获得的烟草疫霉拮抗菌MC2-1进行全基因组测序，并对测序数据进行基因组装、预测、功能注释、共线性分析及次级代谢产物合成基因簇预测。【结果】菌株MC2-1的全基因组大小为3929792 bp，平均GC含量为46.5%，共编码4015个基因；包含tRNA基因86个、rRNA基因27个、sRNA基因81个；含有基因组岛2个、前噬菌体1个、CRISPRCas 9个。在NR、Swiss-Prot、COG、GO和KEGG数据库中分别注释到4015、3347、2996、2841和2223个基因。在CAZyme数据库中注释到几丁质酶、纤维素酶和淀粉酶等可降解植物病原真菌细胞壁的相关酶基因。预测到菌株MC2-1中有12个次级代谢产物合成基因簇，编码表面活性素（Surfactin）、丰原素（Fengycin）、杆菌素（Bacillibactin）、杆菌溶素（Bacilysi...

Whole genome sequencing analysis of a biocontrol bacterium Bacillus velezensis MC2-1

【Objective】 To analyze whole genome information of Bacillus velezensis MC2-1, and to discover genes related to antagonistic substance synthesis in this strain, so as to provide data for biocontrol mechanism research and application.【Method】 Whole genome of antagonistic bacterium MC2-1 isolated from intestinal tract of Periplaneta americana against Phytophthora nicotianae was sequenced using Illumina HiseqII platform and PacbioIII platform, and genome assembly, gene prediction, functional annotation, synteny analysis and prediction of secondary metabolite synthetic gene clusters were conducted.【Result】 The whole genome was 3929792 bp with average GC content of 46.5%, which encoded 4015 genes;and the genome of MC2-1 strain had 86 tRNA, 27 rRNA, 81 sRNA;2 genomic islands, 1 prophage and 9 CRISPR-Cas. In NR, Swiss-Prot, COG, GO and KEGG databases, 4015, 3347, 2996, 2841 and 2223 potential genes were annotated. At the same time, related enzyme genes such as chitinase, cellulase and amylase that could degrade cell wall of phytopathogenic fungi were annotated in the CAZyme database. In addition, 12 secondary metabolite synthesis gene clusters were predicted in MC2-1, encoding inhibitors such as Surfactin, Fengycin, Bacillibactin, Baclysin, Macrolactin H, Bacillaene and Difficidin, most of which were synthesized through non-ribosomal pathway and polyketide synthase pathway and 6 of these gene clusters were highly conserved in B. velezensis.【Conclusion】 Strain MC2-1 genome contains a variety of secondary metabolite-encoding gene clusters, which can encode and synthesize existing antimicrobial substances and genes that can degrade cell wall of phytopathogenic fungi. Therefore, it is predicted that strain MC2-1 can secrete secondary metabolite and enzymes to prevent and control plant disease, enjoying prospect of application in agricultural biocontrol.