胶冻样芽孢杆菌对革兰氏阴性菌的抑菌活性及其抗菌次级代谢产物分析

Analysis of Antibacterial Activity and Secondary Metabolites of Paenibacillus kribbensis against Gram‑negative Bacteria

为筛选对革兰氏阴性菌抑菌活性较好的药用植物芍药的内生菌,采用表面消毒法和平板对峙法分离筛选对大肠杆菌和沙门氏菌有拮抗作用的芍药内生菌,对其进行形态学和分子生物学鉴定,并通过全基因组学分析探究其抗菌活性物质。结果表明,从芍药根、茎、叶等不同组织分离得到20株内生菌。采用平板对峙法抑菌试验,从20株内生菌中获得1株抗菌效果较好的革兰氏阴性内生菌HNYJ291,经形态学和分子方法鉴定为胶冻样芽孢杆菌(Paenibacillus kribbensis),该菌能有效抑制大肠杆菌和沙门氏菌。对该菌进行全基因组测序分析,HNYJ291的基因组大小为5609136 bp,G+C含量为45.48%,预测其编码基因个数为4805个。分别有4779、3678、4027、3941、2994、2700个基因被NR、Swiss-Prot、Pfam、COG、GO、KEGG数据库注释,通过antiSMASH预测到与次级代谢产物合成相关的10个基因簇,主要次级代谢产物有环脂肽类抗生素(Fusaricidin B)、细菌素(Paenilan)、抗菌脂肽(Tridecaptin)、多黏菌素(Polymyxin)和抗菌肽(Paenicidin A)等。从其基因组中含有的抗菌活性物质相关基因簇可以预测出,该菌株具有开发新药和作为可饲用微生物的潜力。

In order to screen the endophytes of Paeonia lactiflora Pall with good antibacterial activity against gram‑negative bacteria,the endophytes of P.lactiflora which have antagonistic effect on Escherichia coli and Salmonella were isolated by surface disinfection and plate face‑off method,and its antibacterial effect and secondary metabolites were studied.The species was identified by morphological observation and 16S rRNA gene sequencing.20 strains of endophytic bacteria were isolated from different tissues such as root,stem and leaf.A gram‑negative endophyte HNYJ291 with good antibacterial effect was obtained from 20 endophyte strains by plate confrontation assay,which was identified as Paenibacillus kribbensis by morphological observation and molecular analysis.The bacteria could effectively inhibit E.coli and Salmonella.Whole genome sequencing analysis showed that the genome size of strain HNYJ291 was 5609136 bp,the GC content was 45.48%,and the number of coding genes was predicted to be 4805.4779,3678,4027,3941,2994 and 2700 genes were annotated by NR,Swiss‑Prot,Pfam,COG,GO and KEGG databases,respectively,and 10 gene clusters related to secondary metabolite synthesis were predicted by antiSMASH.The main secondary metabolites included cyclolipopeptides antibiotics(fusaricidin B),bactericin(paenilan),antimicrobial lipids(tridecaptin),polymyxin and antimicrobial peptides(paenicidin A),etc.From gene clusters related to antibacterial active substances in its genome,it can be predicted that this strain has the potential to develop new drugs and be used as a feedable microorganism.