福建海绵放线菌多样性及其次级代谢产物合成能力

Diversity and secondary metabolite biosynthetic potential of actinomycetes associated with a marine sponge in Fujian

目的分离海洋稀有放线菌并对其进行多样性分析及活性测试。方法采用3种选择性分离培养基从福建海绵中分离放线菌，根据培养特征将分离到的放线菌进行分组，选取各组部分菌种进行16S rRNA基因序列测定并进行系统进化分析，通过BOXPCR指纹进一步分析这些放线菌的多样性。用基于PCR的方法对部分菌株的抗生素生物合成基因进行筛选并对这些菌株的发酵提取液进行抗菌活性测试。结果和结论分离到47株放线菌，根据培养特征将它们分为4组，选取各组部分菌种共23株进行16S rRNA基因序列测定并进行系统进化分析，结果这23株菌在系统进化树上形成6个独立分支（群1～6），分别对应于按培养特征分组的3、2、2、2、1和4组。群1、2、3、4和5属于疣孢菌属（Verrucosispora），群6属于继生菌属（Jishengellal。BOX PCR指纹分析进一步揭示了这些疣孢菌的多样性。基于PCR的基因筛选结果显示97％的菌株具有I型PKS、烯二炔或NRPS生物合成基因片段，抗菌活性测试发现70％的菌株发酵提取液具有抗细菌或真菌活性。

Objective To isolate actinomycetes associated with marine sponge and investigate their diversity and secondary metabolite biosynthetic potentials. Methods A cultivation-based approach was employed to isolate the actinomycetes associated with a marine sponge from East China Sea in Fujian Province. Phylogenetic analysis based on 16S rRNA gene sequences and BOX PCR fingerprint analysis were used to show the diversity of these strains. PCR based gene screening method and antimicrobial assays were used to detect their secondary metabolite biosynthetic potentials. Results and Conclusion A total of 47 strains of actinomycete were isolated by using three different culture media, these strains were assigned to 4 groups by colour grouping. Phylogenetic analysis based on 16S rRNA gene sequences showed that these strains can be classified into 6 distinct clades. Five of the clades belonged to the genus Verrucosispora and one to the genus Jishengella. BOX PCR fingerprint analysis further showed the diversity of these strains. Of the 30 isolates, 97% contained type I PKS, Enediyne PKS or NRPS genes, 70% displayed antimicrobial activity, indicating that these isolates had a high potential to produce active compounds.