The genus Streptomyces is intensively studied due to its excellent ability to produce secondary metabolites with diverse bioactivities. In particular, adequate precursors of secondary metabolites as well as sophisticated post modification systems make some high-yield industrialstrains of Streptomyces the promising chassis for the heterologous production of natural products. However, lack of efficient genetic tools for the manipulation of industrial strains, especially the episomal vector independent tools suitable for large DNA fragment deletion, makes it difficult to remold the metabolic pathways and streamline the genomes in these strains. In this respect, we developed an efficient deletion system independent of the episomal vector for large DNA fragment deletion. Based on this system, four large segments of DNA, ranging in length from 10 kb to 200 kb, were knocked out successfully from three industrial Streptomyces strains without any marker left. Notably, compared to the classical deletion system used in Streptomyces, this deletion system takes about 25% less time in our cases. This work provides a very effective tool for further genetic engineering of the industrial Streptomyces.

中文翻译：

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适用于链霉菌工业菌株的高效无标记缺失系统。

链霉菌属因其产生具有多种生物活性的次级代谢物的出色能力而受到深入研究。特别是充足的次级代谢产物前体以及复杂的后修饰系统使得链霉菌的一些高产工业菌株天然产物异源生产的有前途的底盘。然而，缺乏用于操作工业菌株的有效遗传工具，特别是适用于大 DNA 片段缺失的附加型载体独立工具，使得重塑代谢途径和简化这些菌株的基因组变得困难。在这方面，我们开发了一种独立于附加型载体的高效删除系统，用于大 DNA 片段删除。基于该系统，成功地从三个工业链霉菌菌株中敲除了长度从10 kb到200 kb的四个大片段DNA，并且没有留下任何标记。值得注意的是，与链霉菌中使用的经典删除系统相比，在我们的案例中，这个删除系统花费的时间减少了大约 25%。该工作为进一步对工业链霉菌进行基因工程改造提供了非常有效的工具。