从理论上讲，小基因组菌株或基盘细胞应该具有代谢旺盛和繁殖速度快的特征。但是，很多已报道的结果与人们的期望大相径庭。门多萨假单胞菌NK-01可在胞内积累中长链PHA，同时，向胞外分泌褐藻寡糖，是一株潜在的工业微生物菌株。本项目主要研究内容如下：（1）利用课题组已建立的门多萨假单胞菌无痕敲除操作系统；对已完成测序和生物信息学分析的门多萨假单胞菌NK-01进行基因组精简，在保证必需基因、复制原点及其侧翼基因、PHA和褐藻寡糖合成关联基因存在前提下，进行15-20%左右的基因组精简。完成可分别合成PHA与褐藻寡糖的小基因组菌株的构建，进一步完成基盘细胞的构建；（2）采用Genome Shuffling技术对小基因组菌株进行基因组优化；（3）对小基因组菌株进行生长特征和产物合成的研究；（4）开展复制起始位点移位以及oriC和包括dnaA基因在内的复制起始蛋白的多拷贝研究，以期加快菌体的繁殖速度。

Theoretically, genome-simplified strains or chassis are expected to grow fast and have robust metobolic characteristics. Contrary to these expectations, however, most previous studies failed to achieve these goals. Pseudomonas mendocina NK-01 can accumulate medium-chain-length polyhydroxyalkanoate (PHAMCL) inside the cell and excrete alginate oligosaccharide (AO) simultaneously, and thus is a promising producer for industrial use. The main contents of this project are as following: (1) Using a marker-less gene deletion method developed previously and information from bioinformation analysis of the whole-genome sequence, to conduct genome reduction in P. mendocina NK-01; deleting 15%-20% non-essential chromosomal regions while preserving those essential for cell growth and reproduction and for PHA and AO production; genome-simplified strains for production of PHA and AO will be constructed respectively, to further complete the construction of the Pseudomonas mendocina chassis; (2) Optimization of the genome-simplified strains by genome shuffling; (3) Study growth and production characterization of the genome-simplified strains; (4) Relocating oriC, and introducing multicopy oriC and genes encoding replication proteins (including dnaA) in NK-01 to improve cell growth rate.