基于Methylovorus sp.J1-1基因组尺度代谢网络优化吡咯喹啉醌合成

通过构建Methylovorus sp.J1-1基因组尺度代谢网络模型(genome scale of metabolic network model,GSMM),发掘能够提升吡咯喹啉醌(pyrroloquinoline quinone,PQQ)产量的发酵策略和相关靶基因.基于其注释的基因组和生化信息,构建J1-1的G...

Fermentation Optimization for PQQ Synthesis Based on the Genome-scale Metabolic Model of Methylovorus sp.J1-1

The aim of this study is to explore the fermentation strategies and related target genes that can increase PQQ production by constructing genome-scale metabolic model of Methylovorus sp.J1-1.A genome-scale metabolic model(GSMM)of Methylovorus sp.J1-1 was constructed based on its annotated genome and biochemical information.Subsequently,amino acids and several potential genetic targets that may increase PQQ yield were predicted by COBRApy and validated.The GSMM iKH584 of J1-1 was constructed,containing 584 genes,779 biochemical reactions,121 exchange reactions and 765 metabolites,and it may be used in follow-up simulation.According to the iKH584 simulation,addition of glutamic acid,glutamine and proline,overexpression of the glyA and hps1,and knockout of hps2 all promoted PQQ synthesis.The results showed that the addition of glutamic acid and proline increased PQQ production by 10.4% and 22.9% respectively,overexpression of the glyA and hps1 increased the extracellular concentration of PQQ by 20.6% and 14.6% respectively,and hps2 knockout enhanced PQQ concentration up to 140.84 mg/L and increased by 8.0%,which were consistent with the simulated results,indicating that the metabolic model iKH584 of J1-1 was basically correct.Finally,fed-batch fermentations of J1-1△hps2 in 5 L fermentor were carried out,and the PQQ product reached to 812.64 mg/L,improved 11.1% compared with the parent strain J1-1.Conclusively,the established metabolic model iKH584 of J1-1 can be used to guide the fermentation and strain modification of J1-1 for improving the PQQ yield.