植生拉乌尔菌GDMCC62352应对正十六烷胁迫机制研究

Study on the mechanism of response to n-hexadecane stress by Raoultella planticola GDMCC62352

微生物修复是目前生态系统中石油污染物降解的主要解决方案.因此,本研究以从废水中筛选到降解中链烷烃的植生拉乌尔菌GDMCC62352为研究对象,分析其降解烷烃的分子机制.结果表明,植生拉乌尔菌GDMCC62352在降解第4 d时正十六烷的降解率可达33.5%.通过扫描电镜和透射电镜发现,正十六烷的存在导致菌体之间粘连度降低,表皮皱缩,细胞膜破损,细胞质流出.此外,基因组和转录组学分析发现,植生拉乌尔菌GDMCC62352处于高浓度正十六烷环境体系下菌体调动了大量与烷烃降解相关的基因表达,如Psp系统、群体感应系统、双组分系统、甲烷代谢等途径.本研究为协助石油烃微生物降解扩大菌种代谢途径提供了新的见解.

Microbial remediation is currently the main solution for the degradation of petroleum pollutants in ecosystems.Therefore,this study was conducted to analyze the molecular mechanism of alkane degradation by the Raoultella planticola GDMCC62352,which was screened from wastewater to degrade medium-chain alkanes.Results showed that the degradation of n-hexadecane by R.planticola GDMCC62352 reached up to 33.5%on the 4th day of degradation.Through scanning electron microscopy and transmission electron microscopy,it was found that the presence of n-hexadecane led to the decrease of adhesion between the bacteria,the crumpling of the epidermis,the breakage of the cell membrane,and the outflow of the cytoplasm.Additionally,genomic and transcriptomic analyses revealed that the R.planticola in a high n-hexadecane environmental system mobilized a large number of genes expression related to alkane degradation,such as the Psp system,the quorum sensing system,the two-component system,and methane metabolism pathways.This study provides new insights into the metabolic pathways of expanding strains that assist in the microbial degradation of petroleum hydrocarbons.