生物电化学系统对运动发酵单胞菌代谢的影响

Effect of bio-electrochemical system on the metabolic changes of Zymomonas mobilis

摘要:

生物电化学系统能促进微生物与电极间的相互作用,从而改变微生物的代谢状态。本工作为研究运动发酵单胞菌(Zymomonas mobilis)在电环境中的代谢表现,在外接3V电源的H型电化学发酵装置中测试了其发酵效能。结果表明,相比于无电压的对照,阳极甘油产量上升24%,阴极葡萄糖消耗上升16%,产物乙醇和琥珀酸的产量也分别上升13%和8%。转录组分析表明,代谢物的显著改变归因于电环境导致的有机酸代谢、氧化还原平衡、电子传递等通路的改变。从表达差异显著的基因中挑选了代表胞内氧化还原平衡、生物膜形成和电子传递的3个基因ZMO1060(编码超氧化物歧化酶)、ZMO0401(编码二鸟苷酸磷酸二酯酶)和ZMO1819(编码固氮蛋白)进行验证,结果表明过表达ZMO1060和ZMO1819能够更显著地改变生物电化学系统中Z.mobilis的代谢。本工作为应用生物电化学系统调控微生物代谢物生产提供了参考。

Abstract:

A bio-electrochemical system can promote the interaction between microorganism and electrode and consequently change cellular metabolism. To investigate the metabolic performance of Zymomonas mobilis in the bio-electrochemical system, we applied an H-type bio-electrochemical reactor to control Z. mobilis fermentation under 3 V. Compared with the control group without applied voltage,the glycerol in the anode chamber increased by 24%, while the glucose consumption in the cathode chamber increased by 16%, and the ethanol and succinic acid concentration increased by 13% and 8%,respectively. Transcriptomic analysis revealed that the pathways related to organic acid metabolism,redox balance, and electron transfer played roles in metabolic changes. Three significantly differentially expressed genes, ZMO1060(superoxide dismutase), ZMO0401(diguanylate cyclase), and ZMO1819(nitrogen fixation protein), were selected to verify their functions in the bio-electrochemical system.Overexpression of ZMO1060 and ZMO1819 improved the electrochemical activity of Z. mobilis. This study provides insights into the microbial metabolism regulated by the bio-electrochemical system.