The massive consumption of fossil energy force s people to find new source s of energy.Syngas fermentation has become a hot research field as its high potential in renewable energy production and sustainable developme...The massive consumption of fossil energy force s people to find new source s of energy.Syngas fermentation has become a hot research field as its high potential in renewable energy production and sustainable development.In this study,trophic anaerobic acetogen Morella thermoacetica was successfully immobilized by calcium alginate embedding method.The ability of the immobilized cells on production of acetic acid through syngas fermentation was compared in both airlift and bubble column bioreactors.The bubble column bioreactor was selected as the better type of bioreactor.The production of acetic acid reached 32.3 g·L^(-1) in bubble column bioreactor with a space-time yield of 2.13 g·L^(-1)·d^(-1).The immobilized acetogen could be efficiently reused without significant lag period,even if exposed to air for a short time.A semi-continuous syngas fermentation was performed using immobilized cells,with an average space-time acetic acid yield of 3.20 g·L^(-1)·d^(-1).After 30 days of fermentation,no significant decrea se of the acetic acid production rate was observed.展开更多
Syngas,which contains large amount of CO2 as well as H2 and CO,can be convert to acetic acid chemically or biologically.Nowadays,acetic acid become a cost-effective nonfood-based carbon source for value-added biochemi...Syngas,which contains large amount of CO2 as well as H2 and CO,can be convert to acetic acid chemically or biologically.Nowadays,acetic acid become a cost-effective nonfood-based carbon source for value-added biochemical production.In this study,acetic acid and CO2 were used as substrates for the biosynthesis of 3-hydroxypropionic acid(3-HP)in metabolically engineered Escherichia coli carrying heterogeneous acetyl-CoA carboxylase(Acc)from Corynebacterium glutamicum and codon-optimized malonyl-CoA reductase(MCR)from Chloroflexus aurantiacus.Strategies of metabolic engineering included promoting glyoxylate shunt pathway,inhibiting fatty acid synthesis,dynamic regulating of TCA cycle,and enhancing the assimilation of acetic acid.The engineered strain LNY07(M*DA)accumulated 15.8 g/L of 3-HP with the yield of 0.71 g/g in 48 h by whole-cell biocatalysis.Then,syngas-derived acetic acid was used as substrate instead of pure acetic acid.The concentration of 3-HP reached 11.2 g/L with the yield of 0.55 g/g in LNY07(M*DA).The results could potentially contribute to the future development of an industrial bioprocess of 3-HP production from syngas-derived acetic acid.展开更多
基金supported by the National Key Research and Development Program of China (2019YFA0905000)the National Natural Science Foundation of China (21536004, 21922804, 21776085, and 21871085)the Fundamental Research Funds for the Central Universities (22221818014)。
文摘The massive consumption of fossil energy force s people to find new source s of energy.Syngas fermentation has become a hot research field as its high potential in renewable energy production and sustainable development.In this study,trophic anaerobic acetogen Morella thermoacetica was successfully immobilized by calcium alginate embedding method.The ability of the immobilized cells on production of acetic acid through syngas fermentation was compared in both airlift and bubble column bioreactors.The bubble column bioreactor was selected as the better type of bioreactor.The production of acetic acid reached 32.3 g·L^(-1) in bubble column bioreactor with a space-time yield of 2.13 g·L^(-1)·d^(-1).The immobilized acetogen could be efficiently reused without significant lag period,even if exposed to air for a short time.A semi-continuous syngas fermentation was performed using immobilized cells,with an average space-time acetic acid yield of 3.20 g·L^(-1)·d^(-1).After 30 days of fermentation,no significant decrea se of the acetic acid production rate was observed.
基金supported by the Natural Science Foundation of Shanghai(19ZR1472700)the Fok Ying-Tong Education Foundation,China(Grant No.161017)+2 种基金the National Natural Science Foundation of China(Grant No.21776083)the Fundamental Research Funds for the Central Universities(Grant No.22221818014)supported by Open Funding Project of the CAS Key Laboratory of Synthetic Biology.
文摘Syngas,which contains large amount of CO2 as well as H2 and CO,can be convert to acetic acid chemically or biologically.Nowadays,acetic acid become a cost-effective nonfood-based carbon source for value-added biochemical production.In this study,acetic acid and CO2 were used as substrates for the biosynthesis of 3-hydroxypropionic acid(3-HP)in metabolically engineered Escherichia coli carrying heterogeneous acetyl-CoA carboxylase(Acc)from Corynebacterium glutamicum and codon-optimized malonyl-CoA reductase(MCR)from Chloroflexus aurantiacus.Strategies of metabolic engineering included promoting glyoxylate shunt pathway,inhibiting fatty acid synthesis,dynamic regulating of TCA cycle,and enhancing the assimilation of acetic acid.The engineered strain LNY07(M*DA)accumulated 15.8 g/L of 3-HP with the yield of 0.71 g/g in 48 h by whole-cell biocatalysis.Then,syngas-derived acetic acid was used as substrate instead of pure acetic acid.The concentration of 3-HP reached 11.2 g/L with the yield of 0.55 g/g in LNY07(M*DA).The results could potentially contribute to the future development of an industrial bioprocess of 3-HP production from syngas-derived acetic acid.