“…The concentrations of acetate and succinate were analyzed by HPLC with an aminex HPX-87H ion exclusion column (Bio-Rad, USA). 38 Chromatography was performed on an LC Solutions system (Shimadzu Corporation, Kyoto, Japan) with a refractive index detector (RID-10A, Shimadzu Corporation, Kyoto, Japan). The mobile phase was 5 mM H 2 SO 4 solution at a flow rate of 0.6 mL/min.…”
Section: ■ Materials and Methodsmentioning
confidence: 99%
“…For measuring extracellular metabolites concentrations, cell culture was centrifuged for 10 min at 12 000 rpm and 4 °C, and the supernatant was then filtered through a 0.22-μm syringe filter for HPLC analysis. The concentrations of acetate and succinate were analyzed by HPLC with an aminex HPX-87H ion exclusion column (Bio-Rad, USA) . Chromatography was performed on an LC Solutions system (Shimadzu Corporation, Kyoto, Japan) with a refractive index detector (RID-10A, Shimadzu Corporation, Kyoto, Japan).…”
Acetate, a major component of industrial biological wastewater and of lignocellulosic biomass hydrolysate, could potentially be a less costly alternative carbon source. Here we engineered Escherichia coli MG1655 strain for succinate production from acetate as the sole carbon source. Strategies of metabolic engineering included the blockage of the TCA cycle, redirection of the gluconeogenesis pathway, and enhancement of the glyoxylate shunt. The engineered strain MG03 featuring the deletion of genes: succinate dehydrogenase (sdhAB), isocitrate lyase regulator (iclR), and malic enzymes (maeB) accumulated 6.86 mM of succinate in 72 h. MG03(pTrc99a-gltA) overexpressing citrate synthase (gltA) accumulated 16.45 mM of succinate and the yield reached 0.46 mol/mol, about 92% of the maximum theoretical yield. Resting-cell was adopted for the conversion of acetate to succinate, and the highest concentration of succinate achieved 61.7 mM.
“…The concentrations of acetate and succinate were analyzed by HPLC with an aminex HPX-87H ion exclusion column (Bio-Rad, USA). 38 Chromatography was performed on an LC Solutions system (Shimadzu Corporation, Kyoto, Japan) with a refractive index detector (RID-10A, Shimadzu Corporation, Kyoto, Japan). The mobile phase was 5 mM H 2 SO 4 solution at a flow rate of 0.6 mL/min.…”
Section: ■ Materials and Methodsmentioning
confidence: 99%
“…For measuring extracellular metabolites concentrations, cell culture was centrifuged for 10 min at 12 000 rpm and 4 °C, and the supernatant was then filtered through a 0.22-μm syringe filter for HPLC analysis. The concentrations of acetate and succinate were analyzed by HPLC with an aminex HPX-87H ion exclusion column (Bio-Rad, USA) . Chromatography was performed on an LC Solutions system (Shimadzu Corporation, Kyoto, Japan) with a refractive index detector (RID-10A, Shimadzu Corporation, Kyoto, Japan).…”
Acetate, a major component of industrial biological wastewater and of lignocellulosic biomass hydrolysate, could potentially be a less costly alternative carbon source. Here we engineered Escherichia coli MG1655 strain for succinate production from acetate as the sole carbon source. Strategies of metabolic engineering included the blockage of the TCA cycle, redirection of the gluconeogenesis pathway, and enhancement of the glyoxylate shunt. The engineered strain MG03 featuring the deletion of genes: succinate dehydrogenase (sdhAB), isocitrate lyase regulator (iclR), and malic enzymes (maeB) accumulated 6.86 mM of succinate in 72 h. MG03(pTrc99a-gltA) overexpressing citrate synthase (gltA) accumulated 16.45 mM of succinate and the yield reached 0.46 mol/mol, about 92% of the maximum theoretical yield. Resting-cell was adopted for the conversion of acetate to succinate, and the highest concentration of succinate achieved 61.7 mM.
“…Currently, SA is mainly produced from petrochemical feedstocks through the hydrogenation of maleic acid or maleic anhydride [ 16 ]. However, the bio-based production using low pH yeast fermentation [ 17 – 19 ] or anaerobic fermentation using bacteria [ 20 – 23 ] has been successfully implemented by companies like Myriant [ 24 ], BASF [ 25 ] or BioAmber [ 26 ], offering economically and ecologically attractive alternatives to the conventional petro-based SA production [ 27 – 29 ]. Some examples of SA producing systems are given in Table 1 , including naturally-producing bacteria like Basfia succiniciproducens and Mannheimia succiniproducens and genetically engineered organisms such as E. coli or S. cerevisiae .…”
BackgroundActinobacillus succinogenes is a promising bacterial catalyst for the bioproduction of succinic acid from low-cost raw materials. In this work, a genome-scale metabolic model was reconstructed and used to assess the metabolic capabilities of this microorganism under producing conditions.ResultsThe model, iBP722, was reconstructed based on the functional reannotation of the complete genome sequence of A. succinogenes 130Z and manual inspection of metabolic pathways, covering 1072 enzymatic reactions associated with 722 metabolic genes that involve 713 metabolites. The highly curated model was effective in capturing the growth of A. succinogenes on various carbon sources, as well as the SA production under various growth conditions with fair agreement between experimental and predicted data. Calculated flux distributions under different conditions show that a number of metabolic pathways are affected by the activity of some metabolic enzymes at key nodes in metabolism, including the transport mechanism of carbon sources and the ability to fix carbon dioxide.ConclusionsThe established genome-scale metabolic model can be used for model-driven strain design and medium alteration to improve succinic acid yields.Electronic supplementary materialThe online version of this article (10.1186/s12918-018-0585-7) contains supplementary material, which is available to authorized users.
“…Interestingly, neither class I nor II phosphotransacetylase (crucial enzymes converting acetyl-CoA to acetate in acetogens) have been found in M. thermoacetica based on its genome information (Pierce et al 2008 ); instead, an atypical class III phosphotransacetylase has been identified (Breitkopf et al 2016 ), indicating a unique mechanism for acetate synthesis in this bacterium. In addition, since acetate is an inexpensive chemical and can be easily utilized by many microorganisms, such as Escherichia coli , Saccharomyces cerevisiae , and Corynebacterium glutamicum (Chang et al 2021 ; Chen et al 2021 ; Huang et al 2019 , 2018 ; Lai et al 2021 ; Liu et al 2011 ; Merkel et al 2022 ; Wei et al 2015 ; Xu et al 2021 ; Yang et al 2019 , 2020 ; Zhang et al 2016 ), a two-step bioconversion approach for C1 gas utilization has been proposed, in which M. thermoacetica is responsible for producing acetate from CO 2 /CO and the generated acetate is subsequently converted into other value-added products by acetate-utilizing microorganisms (Huang et al 2019 , 2018 ; Lai et al 2021 ; Liu et al 2011 ; Yang et al 2019 , 2020 ). Fig.…”
Section: Product Synthesis Of
M Thermoaceticamentioning
In the context of the rapid development of low-carbon economy, there has been increasing interest in utilizing naturally abundant and cost-effective one-carbon (C1) substrates for sustainable production of chemicals and fuels. Moorella thermoacetica, a model acetogenic bacterium, has attracted significant attention due to its ability to utilize carbon dioxide (CO2) and carbon monoxide (CO) via the Wood–Ljungdahl (WL) pathway, thereby showing great potential for the utilization of C1 gases. However, natural strains of M. thermoacetica are not yet fully suitable for industrial applications due to their limitations in carbon assimilation and conversion efficiency as well as limited product range. Over the past decade, progresses have been made in the development of genetic tools for M. thermoacetica, accelerating the understanding and modification of this acetogen. Here, we summarize the physiological and metabolic characteristics of M. thermoacetica and review the recent advances in engineering this bacterium. Finally, we propose the future directions for exploring the real potential of M. thermoacetica in industrial applications.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
