调控细胞形态相关基因表达提高P.putidaKT2440突变株KTU-U13生产PHA的能力  

Improve the Ability of Pseudomonas putida KT2440 MutantKTU-U13 to Produce PHA by Regulating the Expression of Cell Morphology-related Genes

作　　者：梁配新 张伊婷 马挺[1] 杨超[1] Liang Peixin;Zhang Yiting;Ma Ting;Yang Chao(Key Laboratory of Molecular Microbiology and Techology for Ministry of Educatiom,Nankai University,Tianjin 300071,China)

机构地区：[1]南开大学分子微生物与技术教育部重点实验室,天津300071

出　　处：《南开大学学报（自然科学版）》2021年第2期37-44,共8页Acta Scientiarum Naturalium Universitatis Nankaiensis

基　　金：天津自然科学基金(17JCZDJC32100,18JCYBJC24500)。

摘　　要：聚羟基脂肪酸酯(PHA)是多种细菌都能合成的一类多元聚酯,它具有类似于合成塑料的物化特性,同时又具备了合成塑料所不具备的生物可降解性、生物相容性、光学活性、气体相隔性等诸多特性,被认为是最有前途的生物塑料之一.P.putida KT2440突变株KTU-U13是本实验室之前构建的生理性能好.PHA产量高的优良底盘细胞,而据文献报道,细胞体积越大越有利于积累更多的包涵体,通过扩展细胞大小,包括长度和宽度,减少PHA颗粒的空间障碍,增加每个细胞的PHA积累,可以提高产量.本实验希望通过调控细胞形态相关基因mreB,ftsZ及sulA的表达进一步提高突变株KTU-U13的PHA产量,结果显示无论对mreB和ftsZ基因进行质粒过表达还是sRNA抑制都没能提高PHA产量,而质粒过表达sul.A基因使PHA产率提高了10.21%.该结果为在突变株KTU-U13的基础上进一步构建PHA高产菌株提供了可参考的策略.Polyhydroxyalkanoate(PHA) can be produced by several kinds of bacteria, which is a kind of multivariate polyester. Its physicochemical properties are similar to the synthetic plastics and it also has many excellent characteristics such as biodegradability, biocompatibility, optical activity and gas separation that synthetic plastics don’t have, so it is considered as one of the most promising bioplastics. P.putida KT2440 mutant strain KTU-U13 is an excellent chassis cell with good physiological performance and high PHA yield constructed by our laboratory. It has been reported that larger cell size is conducive to the accumulation of inclusion bodies. By expanding cell size, including length and width, the spatial barriers of PHA particles are reduced and the PHA accumulation in each cell is increased, which can improve the production. In this study, the PHA production of mutant strain KTU-U13 was further improved by regulating the expression of mreB, ftsZ and sulA genes related to cell morphology. The results showed that neither plasmid overexpression of mreB and ftsZ genes nor sRNA inhibition could improve the PHA production, while plasmid overexpression of sulA gene increased the PHA production titer by 10.21%. These results provide a reference strategy for the further construction of PHA high-yield strains on the basis of mutant strain KTU-U13.

关 键 词：Pseudomonas putida 细胞形态 PHA RT-QPCR 扫描电镜 

分 类 号：Q93[生物学—微生物学]