抗菌和细胞毒活性海洋细菌的筛选及其次生代谢基因证据

Screening and characterization of marine bacteria with antibacterial and cytotoxic activities,and existence of PKS Ⅰ and NRPS genes in bioactive strains

摘要:

从不同海域的海水、海泥和海洋生物中分离海洋细菌,利用琼脂扩散法和MTT法对细菌培养液的乙酸乙酯提取物进行了抗菌和细胞毒活性筛选,并对具有细胞毒活性的细菌菌株进行了16SrRNA系统发生学分析和多聚酮合酶(PKSⅠ型)、非核糖体肽合成酶(NRPS)的筛选。结果显示,在分离到的346株海洋细菌中,42株细菌具有抗菌活性,12株具有细胞毒活性。对12株具有细胞毒活性的细菌菌株进行了16SrRNA系统发生学分析,它们分别属于Agrobacterium,Pseudoalteromons,Bacillus,Paracoccus,Rheinheimera,Aerococcus,Exiguobacterium和Alteromonas8个属。对这12株具有细胞毒活性的细菌菌株进行进一步的PKS和NRPS筛选,得到了4株含有PKSⅠ型的KS结构域或NPRS的A结构域的海洋细菌,为从聚酮和非核糖体肽等生物合成途径去深入研究其次生代谢产物提供了基因学的证据。

Abstract:

Antibacterial and cytotoxic activities were screened for marine bacteria which have been isolated from organism, sediments and seawater in China coastal area. The results showed that 42 isolates had antimicrobial activity and 12 isolates had cytotoxicity. Molecular phylogenetic analysis of marine bacteria with cytotoxicity based on 16S rRNA sequences indicated that they were belong to the genera Aerococcus, Agrobacterium, Alteromona, Bacillus, Exiguobacterium, Paracoccus,Pseudoalteromons, Rheinheimera. Furthermore, marine bacteria with cytotoxicity were also screened for PKS Ⅰ and NRPS genes which could be responsible for bioactive secondary metabolites biosynthesis, 4 strains having KS domain or A domain were obtained, which provide strong evidence that marine bioactive bacteria can produce natural products through PKS and NRPS pathways.