Succinate is an important building block for chemical synthesis.However,during the fermentation process,excessive osmotic stress and byproduct accumulation substantively impair the performance of the microbial cell fa...Succinate is an important building block for chemical synthesis.However,during the fermentation process,excessive osmotic stress and byproduct accumulation substantively impair the performance of the microbial cell factory.To this end,two strategies were proposed.First,an osmo-tolerant mutant,Escherichia coli FMME-N-2,was screened by combined mutagenesis(ARTP and^(60)Co-γirradiation)to produce 51.8 g L^(−1)succinate with a productivity of 0.81 g L^(−1)h^(−1).Second,an oxygen-dependent bifunctional switch(OBS)was developed with promoter PfnrF8-based activation and tobacco etch virus protease-based inhibition functions.With ribosomal binding site(RBS)and degron optimization of OBS,the optimal strain E.coli FMME-N-30 achieved a succinate titer and productivity of 119 g L^(−1)and 1.65 g L^(−1) h^(−1),respectively,in a 30-L fermentor,while only 7.1 g L^(−1)acetate and no formate or lactate were detected.Compared to the wild-type strain E.coli FMME-N,the succinate titer was increased by 3.3-fold.These results highlight the applicability of OBS for the large-scale production of value-added chemicals.展开更多
Cytochrome P450 enzymes(CYPs)catalyze a series of C-H and C=C oxygenation reactions,including hydroxylation,epoxidation,and ketonization.They are attractive biocatalysts because of their ability to selectively introdu...Cytochrome P450 enzymes(CYPs)catalyze a series of C-H and C=C oxygenation reactions,including hydroxylation,epoxidation,and ketonization.They are attractive biocatalysts because of their ability to selectively introduce oxygen into inert molecules under mild conditions.This review provides a comprehensive overview of the C-H and C=C oxygenation reactions catalyzed by CYPs and the various strategies for achieving higher selectivity and enzymatic activity.Furthermore,we discuss the application of C-H and C=C oxygenation catalyzed by CYPs to obtain the desired chemicals or pharmaceutical intermediates in practical production.The rapid development of protein engineering for CYPs provides excellent biocatalysts for selective C-H and C=C oxygenation reactions,thereby promoting the development of environmentally friendly and sustainable production processes.展开更多
The mycelial bacterium Streptomyces is a workhorse for producing natural products,serving as a key source of drugs and other valuable chemicals.However,its complicated life cycle,silent biosynthetic gene clusters(BGCs...The mycelial bacterium Streptomyces is a workhorse for producing natural products,serving as a key source of drugs and other valuable chemicals.However,its complicated life cycle,silent biosynthetic gene clusters(BGCs),and poorly characterized metabolic mechanisms limit efficient production of natural products.There-fore,a metabolic engineering strategy,including traditional and emerging tools from different disciplines,was developed to further enhance natural product synthesis by Streptomyces.Here,current trends in systems metabolic engineering,including tools and strategies,are reviewed.Particularly,this review focuses on recent developments in the selection of methods for regulating the Streptomyces life cycle,strategies for the activation of silent gene clusters,and the exploration of regulatory mechanisms governing antibiotic production.Finally,future challenges and prospects are discussed.展开更多
基金This work was fnancially supported by the National Key R&D Program of China(2020YFA0908500)the Key Program of the National Natural Science Foundation of China(22038005)+1 种基金the Science Fund for Creative Research Groups of the National Science Foundation of China(32021005)the national frst-class discipline program of Light Industry Technology and Engineering(LITE2018-08).
文摘Succinate is an important building block for chemical synthesis.However,during the fermentation process,excessive osmotic stress and byproduct accumulation substantively impair the performance of the microbial cell factory.To this end,two strategies were proposed.First,an osmo-tolerant mutant,Escherichia coli FMME-N-2,was screened by combined mutagenesis(ARTP and^(60)Co-γirradiation)to produce 51.8 g L^(−1)succinate with a productivity of 0.81 g L^(−1)h^(−1).Second,an oxygen-dependent bifunctional switch(OBS)was developed with promoter PfnrF8-based activation and tobacco etch virus protease-based inhibition functions.With ribosomal binding site(RBS)and degron optimization of OBS,the optimal strain E.coli FMME-N-30 achieved a succinate titer and productivity of 119 g L^(−1)and 1.65 g L^(−1) h^(−1),respectively,in a 30-L fermentor,while only 7.1 g L^(−1)acetate and no formate or lactate were detected.Compared to the wild-type strain E.coli FMME-N,the succinate titer was increased by 3.3-fold.These results highlight the applicability of OBS for the large-scale production of value-added chemicals.
基金supported by the National Key R&D Program of China(Grant No.2021YFC2100100 and 2021YFC2102000)the General Program of National Natural Science Foundation of China(Grant No.22178146).
文摘Cytochrome P450 enzymes(CYPs)catalyze a series of C-H and C=C oxygenation reactions,including hydroxylation,epoxidation,and ketonization.They are attractive biocatalysts because of their ability to selectively introduce oxygen into inert molecules under mild conditions.This review provides a comprehensive overview of the C-H and C=C oxygenation reactions catalyzed by CYPs and the various strategies for achieving higher selectivity and enzymatic activity.Furthermore,we discuss the application of C-H and C=C oxygenation catalyzed by CYPs to obtain the desired chemicals or pharmaceutical intermediates in practical production.The rapid development of protein engineering for CYPs provides excellent biocatalysts for selective C-H and C=C oxygenation reactions,thereby promoting the development of environmentally friendly and sustainable production processes.
基金supported by the Science Fund for Creative Re-search Groups of the National Natural Science Foundation of China(32021005)and the National Key R&D Program of China(No.2018YFA0901400).
文摘The mycelial bacterium Streptomyces is a workhorse for producing natural products,serving as a key source of drugs and other valuable chemicals.However,its complicated life cycle,silent biosynthetic gene clusters(BGCs),and poorly characterized metabolic mechanisms limit efficient production of natural products.There-fore,a metabolic engineering strategy,including traditional and emerging tools from different disciplines,was developed to further enhance natural product synthesis by Streptomyces.Here,current trends in systems metabolic engineering,including tools and strategies,are reviewed.Particularly,this review focuses on recent developments in the selection of methods for regulating the Streptomyces life cycle,strategies for the activation of silent gene clusters,and the exploration of regulatory mechanisms governing antibiotic production.Finally,future challenges and prospects are discussed.
