【摘要】 为筛选对革兰氏阳性菌抗菌效果较好的药用植物内生菌，采用表面消毒法和平板对峙法分离筛选对丹毒杆菌、链球菌和葡萄球菌有拮抗作用的迷迭香内生菌，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，从迷迭香根、茎、叶等不同组织中分离得到7株内生菌。采用平板对峙法抑菌试验，从7株内生菌中获得一株抗菌效果较好的革兰氏阳性内生菌HNYJJ2211C，经形态学鉴定和分子生物学鉴定为莫海威芽孢杆菌（Bacillus mojavensis,GCF000245335.1），该菌能有效抑制丹毒杆菌、链球菌和葡萄球菌。对HNYJJ2211C基因组进行测序分析，其基因组大小为4 147 805 bp,G+C含量为43.8%，预测编码基因4 075个。分别有3311、1453、2503、440、158个基因被COG、GO、KEGG、VFDB、CAZy数据库注释；通过antiSMASH软件预测到6个与次级代谢产物合成相关的基因簇；主要次级代谢产物有表面活性素（Surfactin）、杆菌烯（Bacillaene）、脂肽类丰霉素（Fengycin）、多肽类细菌素儿茶酚型杆菌巴汀/嗜铁素类（Bacillibactin）、细菌素（Subtilosin A）及抗真菌化合物的二肽化合物芽孢菌溶素（Bacilysin）等。在HNYJJ2211C基因组中发现含有TasA基因，位于2 480714—2 481499 bp，基因全长786 bp(gene2481)，编码261个氨基酸。从其基因组中含有的抗菌活性物质相关的基因簇可以预测出，该菌株具有开发新药和作为可饲用微生物的潜力。更多还原

【Abstract】 In order to screen endophytes of medicinal plants with good antibacterial effect against gram-positive bacteria,surface disinfection method and plate confrontation method were used to isolate and screen endophytes of rosemary with antagonistic effect against Erysipelothrix rhusiopathiae,Streptococcus and Staphylococcus. Morphological and molecular biological identification of these endophytes were conducted,and their antibacterial active substances were explored through genome analysis. The results showed that seven strains of endophytic bacteria were isolated from different tissues such as roots,stems and leaves of rosemary. A gram-positive endophyte(HNYJJ2211C) with good antibacterial effect was obtained from seven endophyte strains by plate confrontation assay. It was identified as Bacillus mojavensis(GCF000245335. 1)by morphology and molecular identification,which could effectively inhibit Erysipelothrix rhusiopathiae,Streptococcus and Staphylococcus. Whole genome sequencing analysis showed that the genome size of HNYJJ2211C was 4147805 bp,the content of G+C was 43. 8%,and the number of its coding genes was predicted to be 4 075. 3311,1 453,2503,440 and158 genes were annotated by COG,GO,KEGG,VFDB and CAZy respectively. AntiSMASH software predicted that there were six gene clusters related to the synthesis of secondary metabolites. Surfactin,bacillaene,fengycin,bacillibactin,subtilosin A and bacilysin were the main secondary metabolites. In the HNYJJ2211C genome,a gene called TasA was discovered,located at 24 80714—24 814999 bp,having a total length of 786 bp(gene2481)and encoding 261 amino acids. From the gene clusters associated with antibacterial active substances contained in its genome,it can be predicted that this strain has the potential to develop new drugs and serve as a feedable microorganism.更多还原