嗜盐放线菌源铁载体类化合物资源的挖掘

Halophilic actinomycetes possess large potential to produce novel natural products. In our previous studies, a large amount of halophilic actinomycetes strains has been collected from Aiding Lake in Xinjiang; some secondary metabolites and biosynthetic gene clusters from these strains have been found; the large potential of these strains to produce novel siderophores has been demonstrated. Here, biosynthetic pathway based hybridization and PCR, chromazurol-S (CAS) assay and genome mining will be used together to screen these halophilic actinomycetes; strains with possess highest potential to produce novel siderophores will be chosen to find new compounds; bioactivity will be assayed, too. Further more, the relationship of siderophores and microbial community structure in Aiding Lake will be studied, more uncultured halophilic actinomycetes strains could be found. This study will provide new insights into development and utilization of Halophilic actinomycetes resources.

嗜盐放线菌具有产生大量新天然产物的潜力。项目组前期积累了大量新疆艾丁湖嗜盐放线菌资源并开展了次生代谢产物及生物合成基因簇的初步研究，发现该生境嗜盐放线菌具有合成新结构铁载体类化合物巨大潜力。鉴于此，本项目将综合运用生物合成途径特异性探针及引物进行高通量筛选，铁载体螯合活性筛选（CAS显色），以及genome mining筛选3种方法，获得最有潜力产生新颖结构铁载体类化合物的嗜盐放线菌菌株；对潜力菌株进行发酵，寻找新结构铁载体类化合物并初步检测其活性；进一步探索铁载体类化合物对新疆艾丁湖高盐环境中微生物群落结构的影响，探索其对难培养嗜盐放线菌的分离效应，获得更多潜在的嗜盐放线菌资源。本研究将为嗜盐放线菌从物种资源到产物资源的开发利用提供新的思路。

完成新疆3个盐湖（艾丁湖、达坂城盐碱湖、乌尊布拉克湖）放线菌资源评估，结果表明盐湖环境尚有巨大的放线菌新物种资源。收集可培养嗜放线菌1000多株，80%以上菌株具有铁载体活性，复筛出11株高活性菌株，并对其进行了基因组测序及功能基因分析，从中挑选出三株功能基因种类丰富、差异较大的菌株进行代谢产物研究。其中，初步完成了Amycolatopsis sp.YIM 96748的代谢产物研究，获得2个新化合物amycoletates A (1) and B (2)，并进一步对其的24个基因簇开展了异源表达研究，目前已经成功构建56个异源表达工程菌株，其中一个铁离子载体类化合物的基因簇检测到表达，扩大发酵、化合物分离工作正在进行。另外两株Streptomyces sp. YIM 98790和候选新属YIM S01182代谢产物研究还在进行。项目期间，共发表放线菌新属1个，新种6个。发表SCI论文11篇，培养硕士研究生6人。