Development of a microbial dewaxing agent using three spore forming bacteria  

作　　者：Xiaoyan Guo Xutao Zhao Lizhu Li Haibo Jin Jianjun Wang 

机构地区：[1]College of New Materials and Chemical Engineering,Beijing Institute of Petrochemical Technology,Beijing,People’s Republic of China [2]Beijing Key Laboratory of Fuels Cleaning and Advanced Catalytic Emission Reduction Technology,Beijing,People’s Republic of China [3]CAS Key Laboratory of Microbial Physiological and Metabolic Engineering,Institute of Microbiology,Chinese Academy of Sciences,Beijing 100101,P.R.China

出　　处：《Bioresources and Bioprocessing》2024年第1期1063-1075,共13页生物资源与生物加工(英文)

基　　金：the financial support from Scientific Research Program of Beijing Municipal Commission of Education(KM202110017009,granted to Xiaoyan Guo);Undergraduates Research Training Program of Beijing Institute of Petrochemical Technology(2022J00178,granted to Lizhu Li)。

摘　　要：Microbial enhanced oil recovery(MEOR)is a cost effective and efficient method for recovering residual oil.However,the presence of wax(paraffin)in residual oil can substantially reduce the efficiency of MEOR.Therefore,microbial dewaxing is a critical process in MEOR.In this study,a bacterial dewaxing agent of three spore-forming bacteria was developed.Among these bacteria,Bacillus subtilis GZ6 produced the biosurfactant surfactin.Replacing the promoter of the surfactin synthase gene cluster(srfA),increased the titer of surfactin in this strain from 0.33 g/L to 2.32 g/L.The genetically modified strain produced oil spreading rings with diameters increasing from 3.5±0.1 to 4.1±0.2 cm.The LadA F10L/N133R mutant was created by engineering an alkane monooxygenase(LadA)using site-directed mutagenesis in the Escherichia coli host.Compared to the wild-type enzyme,the resulting mutant exhibited an 11.7-fold increase in catalytic efficiency toward the substrate octadecane.When the mutant(pIMPpladA2mu)was expressed in Geobacillus stearothermophilus GZ178 cells,it exhibited a 2.0-fold increase in octadecane-degrading activity.Cultures of the two modified strains(B.subtilis GZ6(pg3srfA)and G.stearothermophilus GZ178(pIMPpladA2mu))were mixed with the culture of Geobacillus thermodenitrificans GZ156 at a ratio of 5:80:15.The resulting composition increased the rate of wax removal by 35%compared to the composition composed of three native strains.This study successfully developed a multi-strain bacterial agent with enhanced oil wax removal capabilities by genetically engineering two bacterial strains.

关 键 词：Alkane monooxygenase Microbial enhanced oil recovery Microbial wax removal agent SURFACTIN 

分 类 号：R58[医药卫生—内分泌]