外源质粒电击转入Pseudomonas putida的条件研究

以自行筛选的恶臭假单胞菌（Pseudomonas putida）(命名为Rs198，Genbank登录号为FJ788425）为受体菌，将具有卡那霉素抗性标记的大肠杆菌假单胞菌穿梭质粒PDSK519通过电转化法导入到受体菌中，对细胞生长状态、电转化温度、质粒DNA及感受态细胞浓度、电击电压及电转化介质给予转化效率的影响进行研究。结果表明，在细胞生长至OD600为0.5左右时收集菌体，在低温条件下制备浓度为 4.6×1012/ml 的感受态细胞，以0.3mol/L的蔗糖为电转化介质，在13kV/cm的场强下电击能获得较高的转化效率，最高可达1.3×107个转化子/μ g DNA。为构建恶臭假单胞的遗传转化系统，利用基因工程手段为该菌的进一步研究奠定了理论基础。

Study on Electrotransformation of vitro DNA into Pseudomonas putida

Pseudomonas putida isolated relieving salt stress and promoting plant growth was used as the recipient strain. Optimum conditions including growth stage of the strain, concentration of competent cell, electroshock voltage and the meduim were investigated for the electroporation of P.putidaE.coli shulter vector PDSK519 into P.putida Rs198. It was showed that the highest transformation efficiency was up to 1.3×107CFU/μ g DNA in the optimium condition, under which the competent cells were collected at logarithmic growth phase(OD600=0.5), the mixture of the competent cells(4.6×1012/ml) and PDSK519 plasmid DNA was electroporated at 13kV/cm. It will be very helpful for developing a genetic transformation system and studying the genomic function of P.putida.