Analysis the Ability of Producing Secondary Metabolites of Streptomyces bingchenggensis By The Genome Sequence and GeneChip DNA microarrays

Streptomyces bingchenggensis is a soil bacterium that produces a family of macrolide antibiotics, milbemycins, which is commercially important in crop protection, human and veterinary medicine. After the complete genome sequence, and annotation, for further development of our gene expression approach to biosynthesis, we have employed whole genome microarray expression profiling as a discovery platform to obtain improved specificity and sensitivity of gene expression analysis, allowing a global and at the same time detailed picture of how gene clusters for secondary metabolism are modulated. In the result, we confirmed the expression mil and nan gene cluster, furthermore, pks3, pks5 and nrps7, nrps8 also showed significant gene expression, but no obvious products detected. In Streptomyces bingchenggensis, there are also corresponding genes belonging to Defense mechanisms, which is much more than other Streptomyces, for the resistance of own metabolites and dealing with complex environmental factors. 16 time points were designed at 12, 18, 24, 30, 33, 39, 42, 45, 51, 57, 60, 69, 72, 96, 120, and 144 hours. The samples were collected at each time point named L1, L3, L5, L7, L8, L10, L11, L12, L14, L16, L17, L20, L21, L22, L23, and L24.

冰城链霉菌（Streptomyces bingchenggensis）是一种土壤源细菌，可分泌一类大环内酯类抗生素——米尔贝霉素（milbemycins），该类物质在作物保护、人类医学与兽用药物领域均具备重要商业价值。在完成全基因组测序与注释后，为进一步优化我们用于生物合成研究的基因表达分析方法，本研究采用全基因组微阵列表达谱作为发现平台，以提升基因表达分析的特异性与灵敏度，从而实现对次级代谢基因簇调控模式的全局且精细化解析。实验结果证实，mil与nan基因簇存在表达；此外，pks3、pks5以及nrps7、nrps8亦呈现出显著的基因表达水平，但未检测到对应的明显产物。冰城链霉菌中还存在大量隶属于防御机制的相关基因，其数量多于其他链霉菌，用于抵御自身代谢产物并应对复杂环境胁迫。本研究设置了16个采样时间点，分别为12、18、24、30、33、39、42、45、51、57、60、69、72、96、120及144小时，各时间点对应的样本依次命名为L1、L3、L5、L7、L8、L10、L11、L12、L14、L16、L17、L20、L21、L22、L23及L24。