Vitamin B_(12)is a complex compound synthesized by microorganisms.The industrial production of vitamin B_(12)relies on specific microbial fermentation processes.E.coli has been utilized as a host for the de novo biosy...Vitamin B_(12)is a complex compound synthesized by microorganisms.The industrial production of vitamin B_(12)relies on specific microbial fermentation processes.E.coli has been utilized as a host for the de novo biosynthesis of vitamin B_(12),incorporating approximately 30 heterologous genes.However,a metabolic imbalance in the intricate pathway significantly limits vitamin B_(12)production.In this study,we employed multivariate modular metabolic engineering to enhance vitamin B_(12)production in E.coli by manipulating two modules comprising a total of 10 genes within the vitamin B_(12)biosynthetic pathway.These two modules were integrated into the chromosome of a chassis cell,regulated by T7,J23119,and J23106 promoters to achieve combinatorial pathway optimization.The highest vitamin B_(12)titer was attained by engineering the two modules controlled by J23119 and T7 promoters.The inclusion of yeast powder to the fermentation medium increased the vitamin B_(12)titer to 1.52 mg/L.This enhancement was attributed to the effect of yeast powder on elevating the oxygen transfer rate and augmenting the strain’s isopropyl-β-D-1-thiogalactopyranoside(IPTG)tolerance.Ultimately,vitamin B_(12)titer of 2.89 mg/L was achieved through scaled-up fermentation in a 5-liter fermenter.The strategies reported herein will expedite the development of industry-scale vitamin B_(12)production utilizing E.coli.展开更多
基金supported by the National Key R&D Program of China(2018YFA0903700)the National Natural Science Foundation of China(22178372,22208367)+2 种基金National Science Fund for Distinguished Young Scholars(22325807)the Tianjin Synthetic Biotechnology Innovation Capacity Improvement Project(TSBICIP-KJGG-011,TSBICIP-CXRC-055,TSBICIP-PTJJ-007)Youth Innovation Promotion Association,Chinese Academy of Sciences(2020182).
文摘Vitamin B_(12)is a complex compound synthesized by microorganisms.The industrial production of vitamin B_(12)relies on specific microbial fermentation processes.E.coli has been utilized as a host for the de novo biosynthesis of vitamin B_(12),incorporating approximately 30 heterologous genes.However,a metabolic imbalance in the intricate pathway significantly limits vitamin B_(12)production.In this study,we employed multivariate modular metabolic engineering to enhance vitamin B_(12)production in E.coli by manipulating two modules comprising a total of 10 genes within the vitamin B_(12)biosynthetic pathway.These two modules were integrated into the chromosome of a chassis cell,regulated by T7,J23119,and J23106 promoters to achieve combinatorial pathway optimization.The highest vitamin B_(12)titer was attained by engineering the two modules controlled by J23119 and T7 promoters.The inclusion of yeast powder to the fermentation medium increased the vitamin B_(12)titer to 1.52 mg/L.This enhancement was attributed to the effect of yeast powder on elevating the oxygen transfer rate and augmenting the strain’s isopropyl-β-D-1-thiogalactopyranoside(IPTG)tolerance.Ultimately,vitamin B_(12)titer of 2.89 mg/L was achieved through scaled-up fermentation in a 5-liter fermenter.The strategies reported herein will expedite the development of industry-scale vitamin B_(12)production utilizing E.coli.
