可培养海绵共附生微生物的PKS基因筛选

Polyketide Synthases Screening from Sponge_associated Culturable Microorganisms

摘要:

利用PCR技术对21株分离自我国南海澳大利亚厚皮海绵的放线菌及9株分离自贪婪倔海绵的芽孢杆菌进行了聚酮合酶（PKS）基因筛选。从芽孢杆菌C89中获得了一条669bp片段, BLAST比对结果表明该基因对应的氨基酸序列和枯草芽孢杆菌I 型聚酮合成酶基因（PKS）KS域的相似性达96%。通过系统发育分析推测芽孢杆菌C89 PKS基因属于trans-AT型。首次证明了贪婪倔海绵共附生微生物中存在PKS基因，这为海绵活性物质的微生物来源假说提供了证据；同时也为可以产生聚酮类化合物的微生物筛选以及聚酮类化合物的发酵制备奠定了基础。

Abstract:

PKS gene was screened by PCR from thirty strains of spone-associated bacteria including twenty-one actinomycetes isolated from Craniella anstrialiensis and nine bacillus isolated from Dysidea avara in the South China Sea. As a result, a 669 bp KS domain gene was successfully amplified from Bacillus C89. BLAST analysis showed that the KS domains were most closely related to the KS sequences of Bacillus subtilis subsp.subtilis str.168 with 96% similarity. Phylogenetic analysis demonstrated the KS domain belong to trans-AT KS domains. This study demonstrated the existence of PKS gene in bacteria associated with sponge Dysidea avara for the first time, and provided proof for the hypothesis that sponge-associated bacteria are perhaps the true producers of many novel bioactive compounds in sponge. Meanwhile, this study lays a basis for the microbial screening for polyketide compounds production.