摘要
目的对分离自广西北仑河口红树林根际土壤的两株放线菌(B200、B205)进行抗菌活性研究及鉴定。方法观察两株放线菌的形态特征;通过PCR扩增、测定并比对16S rRNA基因序列,采用邻接法构建系统发育树并进行分析;通过液体发酵、萃取等方法,分别获得发酵液水相、发酵液酯相和菌丝丙酮浸提液三类样品;样品通过纸片扩散法进行抗菌活性测定。结果从红树林根际土壤分离的两株放线菌,其发酵液具有较强的广谱抗菌活性,菌株的16S rRNA基因序列对比结果显示,菌株B200和B205分别与有效发表菌株Agromyces subbeticus DSM16689~T的相似率为98.01%和Micromonospora rosaria DSM 803~T的相似率为99.73%,菌株B200可能为壤霉菌属潜在新种,B205初步鉴定是小单孢菌Micromonospora rosaria DSM 803~T的变种。结论分离自广西北仑河口红树林根际土壤的两株放线菌其次级代谢产物有较强抗菌活性,具有从中发现新抗生素的潜力。
Aim To identify and study antimicrobial acticity of actinomycetes isolated from mangrove rhizosphere soils in Beilun Estuary,Guangxi,China. Methods The typical morphological characteristics of two actinomycetes were observed. To determine the phylogenetic position of the isolates,16S rRNA gene sequences were obtained by PCR amplification and direct sequencing,and then compared with the gene database,the phylogenetic tree was constructed using the neighboring method. Crude extracts were obtained from fermentation broth extracted by ethyl acetate and mycelia extracted by acetone,respectively. The antibacterial and antifungal activities of the crude extracts were evaluated using the disk diffusion method. Results Significant broad-spectrum antibacterial activities of two actinomycetes were isolated from mangrove rhizosphere soils in Beilun Estuary. The highest similarity of 16S rRNA gene sequence between strain B200 and the validly described species Agromyces subbeticus DSM16689~T,between strain B205 and the validly described species Micromonospora rosaria DSM803Twas98. 01% and 99. 73%,respectively,which indicated that the strain B200 was Agromyces potential new taxa,and B205 was identified as Micromonospora rosaria DSM 803 Tvariants. Conclusions Two actinomycetes isolated from mangrove rhizosphere soils in Beilun Estuary,Guangxi,and its fermentation products show significant antibacterial activity. Mangrove rhizosphere soils are rich in culturable medicinal actinobacteria,which could be a potential source for the discovery of new antibiotics,and deserves further research.
出处
《中国药理学通报》
CAS
CSCD
北大核心
2017年第6期813-818,共6页
Chinese Pharmacological Bulletin
基金
国家自然科学基金资助项目(No 81460537)
广西省自然科学基金资助项目(No 2014GXNSFAA118196)
关键词
北仑河口
红树林
放线菌
抗菌活性
耐药菌
16S
RRNA
Beilun Estuary
mangrove
actinomycetes
antibiotic activity
drug resistant bacteria
16S rRNA
