Background:Second-generation feedstocks such as lignocellulosic hydrolysates are more and more in the focus of sustainable biotechnological processes.Corynebacterium glutamicum,which is used in industrial amino acid p...Background:Second-generation feedstocks such as lignocellulosic hydrolysates are more and more in the focus of sustainable biotechnological processes.Corynebacterium glutamicum,which is used in industrial amino acid production at a million-ton scale,has been engineered towards utilization of alternative carbon sources.As for other microorganisms,the focus has been set on the pentose sugars present in lignocellulosic hydrolysates.Utilization of the hexuronic acids D-galacturonic acid(abundant in pectin-rich waste streams such as peels and pulps)and D-glucuronic acid(a component of the side-chains of plant xylans)for growth and production with C.glutamicum has not yet been studied.Results:Neither aldohexuronic acid supported growth of C.glutamicum as sole or combined carbon source,although its genome encodes a putative uronate isomerase sharing 28%identical amino acids with UxaC from Escherichia coli.Heterologous expression of the genes for both uptake and catabolism of D-galacturonic acid and D-glucuronic acid was required to enable growth of C.glutamicum with either aldohexuronic acid as the sole carbon source.When present in mixtures with glucose,the recombinant C.glutamicum strains co-utilized D-galacturonate with glucose and D-glucuronate with glucose,respectively.When transformed with the plasmid for uptake and catabolism of the aldohexuronates,model producer strains were able to grow with and produce from D-galacturonate or D-glucuronate as sole carbon source.Conclusions:An easily transferable metabolic engineering strategy for access of C.glutamicum to aldohexuronates was developed and applied to growth and production of the amino acids L-lysine and L-ornithine as well as the terpene lycopene from D-galacturonate or D-glucuronate.展开更多
Deciphering gene function is fundamental to engineering of microbiology.The clustered regularly interspaced short palindromic repeats(CRISPR)system has been adapted for gene repression across a range of hosts,creating...Deciphering gene function is fundamental to engineering of microbiology.The clustered regularly interspaced short palindromic repeats(CRISPR)system has been adapted for gene repression across a range of hosts,creating a versatile tool called CRISPR interference(CRISPRi)that enables genome-scale analysis of gene function.This approach has yielded significant advances in the design of genome-scale CRISPRi libraries,as well as in applica-tions of CRISPRi screening in medical and industrial microbiology.This review provides an overview of the recent progress made in pooled and arrayed CRISPRi screening in microorganisms and highlights representative studies that have employed this method.Additionally,the challenges associated with CRISPRi screening are discussed,and potential solutions for optimizing this strategy are proposed.展开更多
Corynebacterium glutamicum is a microbial production host established in the industry 60 years ago.It is mainly used for production of feed and food amino acids.As C.glutamicum strain development has been cutting edge...Corynebacterium glutamicum is a microbial production host established in the industry 60 years ago.It is mainly used for production of feed and food amino acids.As C.glutamicum strain development has been cutting edge since its discovery,it has been engineered for production of a plethora of valuable products.This review will focus on recent developments of C.glutamicum strain engineering for biotransformation and fermentation processes towards flavor and fragrance molecules as well as pigments and sweeteners.展开更多
Indole is a signalling molecule produced both by bacteria and plants.In this review its signalling role between microbes and in particular in the human gut is discussed.Besides the natural roles,indole also has value ...Indole is a signalling molecule produced both by bacteria and plants.In this review its signalling role between microbes and in particular in the human gut is discussed.Besides the natural roles,indole also has value for flavour and fragrance applications,for example,in food industry or perfumery.Additionally,indole can be derivatized to several halogenated and oxygenated compounds that can be used as natural colourants or have promising bioactivity with therapeutic potential to treat human diseases.Indole is traditionally obtained from coal tar.Biocatalytic approaches have been developed to convert indole into halogenated and oxygenated derivatives.This review will discuss recent advances in production of indole from glucose or tryptophan by fermentation and the production of derived halogenated and oxygenated derivatives by microbial cell factories.展开更多
基金the authors was funded in part by grants 0315589G from BMBF in the CRP‘Corynebacterium:improving flexibility and fitness for industrial production’.
文摘Background:Second-generation feedstocks such as lignocellulosic hydrolysates are more and more in the focus of sustainable biotechnological processes.Corynebacterium glutamicum,which is used in industrial amino acid production at a million-ton scale,has been engineered towards utilization of alternative carbon sources.As for other microorganisms,the focus has been set on the pentose sugars present in lignocellulosic hydrolysates.Utilization of the hexuronic acids D-galacturonic acid(abundant in pectin-rich waste streams such as peels and pulps)and D-glucuronic acid(a component of the side-chains of plant xylans)for growth and production with C.glutamicum has not yet been studied.Results:Neither aldohexuronic acid supported growth of C.glutamicum as sole or combined carbon source,although its genome encodes a putative uronate isomerase sharing 28%identical amino acids with UxaC from Escherichia coli.Heterologous expression of the genes for both uptake and catabolism of D-galacturonic acid and D-glucuronic acid was required to enable growth of C.glutamicum with either aldohexuronic acid as the sole carbon source.When present in mixtures with glucose,the recombinant C.glutamicum strains co-utilized D-galacturonate with glucose and D-glucuronate with glucose,respectively.When transformed with the plasmid for uptake and catabolism of the aldohexuronates,model producer strains were able to grow with and produce from D-galacturonate or D-glucuronate as sole carbon source.Conclusions:An easily transferable metabolic engineering strategy for access of C.glutamicum to aldohexuronates was developed and applied to growth and production of the amino acids L-lysine and L-ornithine as well as the terpene lycopene from D-galacturonate or D-glucuronate.
基金supported by the National Key R&D Program of China(2018YFA0901500)the National Natural Science Foundation of China(32222004 and 32270101)the Youth Innovation Promotion Association of Chinese Academy of Sciences(2021177).
文摘Deciphering gene function is fundamental to engineering of microbiology.The clustered regularly interspaced short palindromic repeats(CRISPR)system has been adapted for gene repression across a range of hosts,creating a versatile tool called CRISPR interference(CRISPRi)that enables genome-scale analysis of gene function.This approach has yielded significant advances in the design of genome-scale CRISPRi libraries,as well as in applica-tions of CRISPRi screening in medical and industrial microbiology.This review provides an overview of the recent progress made in pooled and arrayed CRISPRi screening in microorganisms and highlights representative studies that have employed this method.Additionally,the challenges associated with CRISPRi screening are discussed,and potential solutions for optimizing this strategy are proposed.
基金funding enabled and organized by Projekt DEAL.Support in the framework of the ERA CoBioTech project INDIE(European Union’s Horizon 2020 research and innovation programme under grant agreement No.722361)with national funding is acknowledged by KC(Dutch research council(NWO)grant number 053.80.732)and VFW(Renewable Resources Scheme(FNR)of the Federal Ministry of Food and Agriculture,Germany,grant number 22023517).NAH acknowledges funding by BMBF project KaroTec(grant number:03VP09460).
文摘Corynebacterium glutamicum is a microbial production host established in the industry 60 years ago.It is mainly used for production of feed and food amino acids.As C.glutamicum strain development has been cutting edge since its discovery,it has been engineered for production of a plethora of valuable products.This review will focus on recent developments of C.glutamicum strain engineering for biotransformation and fermentation processes towards flavor and fragrance molecules as well as pigments and sweeteners.
基金Open Access funding enabled and organized by Projekt DEAL.Support of the ERA CoBioTech project INDIE(European Union’s Horizon 2020 research and innovation programme under grant agreement No.722361)with national funding is acknowledged by KC and MM(Dutch research council(NWO)grant number 053.80.732)LF and VFW(Renewable Resources Scheme(FNR)of the Federal Ministry of Food and Agriculture,Germany,grant number 22023517).
文摘Indole is a signalling molecule produced both by bacteria and plants.In this review its signalling role between microbes and in particular in the human gut is discussed.Besides the natural roles,indole also has value for flavour and fragrance applications,for example,in food industry or perfumery.Additionally,indole can be derivatized to several halogenated and oxygenated compounds that can be used as natural colourants or have promising bioactivity with therapeutic potential to treat human diseases.Indole is traditionally obtained from coal tar.Biocatalytic approaches have been developed to convert indole into halogenated and oxygenated derivatives.This review will discuss recent advances in production of indole from glucose or tryptophan by fermentation and the production of derived halogenated and oxygenated derivatives by microbial cell factories.
