Study On Riboflavin-Mediated Electron Transmission Of Engineering Shewanella Oneidensis

Microbial fuel cell(MFC)is a renewable technology that can convert organic waste into electrical energy.Bacteria catalyze the decomposition of the carbon source and transfer the released electrons to the anode of the MFC through various extracellular electron transfer(EET)mechanisms.However,low power output is still the main bottleneck in the practical application of MFC.One strategy to increase the power output of MFC is to increase the EET efficiency between bacteria and anode,and another strategy is to increase the releasable intracellular electron pool in bacterial cells.This topic uses synthetic biology technology,combined with cofactor engineering and metabolic engineering methods,through module fine-tuning combination adaptation strategy,multi-module combination electron transmission path.Using the Biobrick method,the three modules of NAD~+synthesis,NADH/NAD~+ratio,and riboflavin were expressed with different promoters combined with different replicons to optimize NAD~+synthesis,NADH/NAD~+ratio,and the amount of riboflavin.Break the limitation of single plasmid expression,use the dual plasmid system to express multiple modules,and promote NAD~+synthesis,NADH/NAD~+ratio,and riboflavin synthesis.Finally,it was found that promoting the increase of the intracellular and extracellular power generation efficiency at the same time is not suitable for improving the power generation performance of Shewanella oneidensis.The introduction of the Shewanella oneidensis heterologous flavin pathway can promote the improvement of intracellular NADH.Therefore,we further used transcriptome sequencing technology to study the mechanism of the heterologous riboflavin pathway of Shewanella to improve the electricity production performance of Shewanella oneidensis.Using sequencing data and various analysis methods,the differential expression was analyzed.Gene,and its further engineering transformation,finally found that AhpC,HemB genes greatly reduced the internal resistance of MFC,and increased the output power of MFC.This study was the first to use transcriptome sequencing technology to study the mechanism of the heterologous synthetic flavin introduced by Shewanella oneidensis to improve the electricity production performance of Shewanella oneidensis,and discovered that the AhpC and HemB genes significantly improved the single strain of Shewanella oneidensis.The expression ability of the cell riboflavin is of great significance to the improvement of the MFC’s electrical performance.These genes provide more possibilities for the research on the molecular level of electricity-producing microorganisms,and open up ideas for the research of Shewanella oneidensis at the omics level.