采用合成生物学方法建立高效合成中长链PHA的恶臭假单胞菌KT2440小基因组细胞工厂

如何利用微生物高效合成目的产物是合成生物学的核心科学问题之一。微生物合成的中长链聚羟基脂肪酸酯（mcl-PHA）具有广泛的应用前景，但目前产量低、生产成本高，已成为制约其产业化的关键因素。已报道，基因组删减的微生物菌株表现出优良的生理特性。本项目首先对mcl-PHA合成菌株恶臭假单胞菌KT2440（Pseudomonas putida KT2440）的基因组岛进行系统性删除，然后通过对基因组删减菌株的生理特性进行测试，从而筛选出具有优良生产性能的优势小基因组菌株KT2440，这为构建高效的细胞工厂提供有用的测试平台。进一步，采用合成生物学方法包括启动子工程、代谢工程和细胞形态工程对优势小基因组菌株KT2440进行系统性改造，建立高效合成mcl-PHA的P. putida KT2440小基因组细胞工厂。

How to use microorganisms to synthesize target products efficiently is one of the core scientific problems in synthetic biology. The medium-chain-length polyhydroxyalkanoate (mcl-PHA) synthesized by microorganism has a wide application prospect, but at present, the low yield and high production cost have become the key factors restricting its industrialization. It has been reported that the genome-reduced microbial strains show many excellent physiological characteristics. In this project, the genomic islands (GIs) of a mcl-PHA-producing strain Pseudomonas putida KT2440 were deleted systematically, and then the physiological characteristics of the genome-reduced strains were tested to select the dominant minimal genome strain KT2440 with excellent production performance, which will provide a useful test platform for constructing efficient microbial cell factories. Furthermore, the dominant minimal genome strain KT2440 was systematically engineered by using the approaches of synthetic biology, including promoter engineering, metabolic engineering and cell morphology engineering, to establish a minimal genome cell factory of P. putida KT2440 for efficient synthesis of mcl-PHA.