海绵复杂共生体中放线菌新分类单元及新活性物质发现

Marine sponges, the most ancient complex symbionts, contain dense and diverse associated microorganisms as significant sources of novel marine actinomycetes, new genes and new bioactive compounds. Recnetly, 54 actinomycete strains were isolated from 2 high actinomycetes abundance marine sponges collected off Xisha islands by applicant and assigned to 7 genus and 36 species by phylogenetic characterization, including 5 strains were potential candidates for 1 new genus and 4 new species respectively. The HPLC-MS analysis screening exhibited diverse chemical structural information from 2 strains..Therefore, we expected to obtain more actinomycetes from marine sponge by exploring better isolate and culture methods. The diversity and novelty of cultured actinomycetes in marine sponge will be recognized by phylogenetic analysis and the potential candidates for new taxa will be identified through polyphasic approach. Then the diversity of PKS/NRPS genes and potential of producing new active compounds will be assessed with the techniques of molecular biology, bioinformatics and natural product chemistry, under the guide of antibiosis and antitumor activities. And find secondary metabolites with novel structure and significant bioactivities by fermentation optimization, chemical isolation and spectrum identification techniques. At last we will establish the actinomycetes isolate and culture system for complex symbionts marine sponge, and exploit novel taxa, new genes and new bioactive compounds from the strains with multiscale path including taxonomy novelty, genetic, chemical and bioactivity diversities.

海绵作为最古老、最复杂的共生生物，蕴含丰富的共附生微生物，是新颖海洋放线菌、新基因和新活性化合物的重要来源。申请人前期从放线菌类群丰富的2种西沙海绵中分离获得7个属、36个种共54株放线菌，发现了1个新属和4个新种，通过色谱/质谱联用分析获得了2个化学多样性丰富的菌株。.本课题拟设计和优化分离培养条件，获得更多放线菌；通过系统发育分析，阐明海绵共生体中可培养放线菌的多样性和新颖性，对疑似新属和新种开展多相分类鉴定；以抗菌、抗肿瘤活性为导向，应用分子生物学、生物信息学、天然产物化学等技术手段，评价菌株的PKS/NRPS合成基因簇多样性和产活性产物的潜力；通过发酵优化、化学分离和波谱鉴定技术，发现结构新颖、生物活性显著的次生代谢产物。建立海绵复杂共生体放线菌分离培养体系，从分类学新颖性、遗传多样性以及化学与生物活性多样性等多尺度发掘海绵放线菌次生代谢潜力，发现新分类单元、新基因及新活性化合物。

从南海海绵样本共分离纯化了约400株放线菌，初步归属了363株，其中至少30株代表潜在的新分类单元；发现并多鉴定了1个新属（链孢囊菌科Streptosporangiaceae）、5个新种（Streptomyces 2、Micromonospora 1、Actinomadura 1、Geodermatophilus 1），对小单孢科的继生菌属（Jishengella）进行了重新鉴定和归属；挖掘了链孢囊菌科新属等多个放线菌的次生代谢产物，获得单体化合物44个，包括13个新化合物。在项目的资助下共发表第一标注SCI论文5篇。