scholarly journals Metabolic engineering of Moorella thermoacetica for thermophilic bioconversion of gaseous substrates to a volatile chemical

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Junya Kato ◽  
Kaisei Takemura ◽  
Setsu Kato ◽  
Tatsuya Fujii ◽  
Keisuke Wada ◽  
...  
Keyword(s):  
Carbon Flux ◽  
Cost Effective ◽  
Gas Composition ◽  
Autotrophic Growth ◽  
Acetyl Coenzyme A ◽  
Volatile Chemicals ◽  
Moorella Thermoacetica ◽  
Gas Fermentation ◽  
Dry Cell ◽  
Co Gas

AbstractGas fermentation is one of the promising bioprocesses to convert CO2 or syngas to important chemicals. Thermophilic gas fermentation of volatile chemicals has the potential for the development of consolidated bioprocesses that can simultaneously separate products during fermentation. This study reports the production of acetone from CO2 and H2, CO, or syngas by introducing the acetone production pathway using acetyl–coenzyme A (Ac-CoA) and acetate produced via the Wood–Ljungdahl pathway in Moorella thermoacetica. Reducing the carbon flux from Ac-CoA to acetate through genetic engineering successfully enhanced acetone productivity, which varied on the basis of the gas composition. The highest acetone productivity was obtained with CO–H2, while autotrophic growth collapsed with CO2–H2. By adding H2 to CO, the acetone productivity from the same amount of carbon source increased compared to CO gas only, and the maximum specific acetone production rate also increased from 0.04 to 0.09 g-acetone/g-dry cell/h. Our development of the engineered thermophilic acetogen M. thermoacetica, which grows at a temperature higher than the boiling point of acetone (58 °C), would pave the way for developing a consolidated process with simplified and cost-effective recovery via condensation following gas fermentation.

scholarly journals Metabolic Engineering of Moorella Thermoacetica for Thermophilic Bioconversion of Gaseous Substrates to a Volatile Chemical

2021 ◽  
Author(s):  
Junya Kato ◽  
Kaisei Takemura ◽  
Setsu Kato ◽  
Tatsuya Fujii ◽  
Keisuke Wada ◽  
...  
Keyword(s):  
Carbon Flux ◽  
Cost Effective ◽  
Gas Composition ◽  
Autotrophic Growth ◽  
Acetyl Coenzyme A ◽  
Volatile Chemicals ◽  
Moorella Thermoacetica ◽  
Gas Fermentation ◽  
Dry Cell ◽  
Co Gas

Abstract Gas fermentation is one of the promising bioprocesses to convert CO2 or syngas to important chemicals. Thermophilic gas fermentation of volatile chemicals has the potential for the development of consolidated bioprocesses that can simultaneously separate products during fermentation. This study reports the production of acetone from CO2 and H2, CO, or syngas by introducing the acetone production pathway using acetyl–coenzyme A (Ac-CoA) and acetate produced via the Wood–Ljungdahl pathway in Moorella thermoacetica. Reducing the carbon flux from Ac-CoA to acetate through genetic engineering successfully enhanced acetone productivity, which varied on the basis of the gas composition. The highest acetone productivity was obtained with CO–H2, while autotrophic growth collapsed with CO2–H2. By adding H2 to CO, the acetone productivity from the same amount of carbon source increased compared to CO gas only, and the maximum specific acetone production rate also increased from 0.04 to 0.09 g-acetone/g-dry cell/h. Our development of the engineered thermophilic acetogen M. thermoacetica, which grows at a temperature higher than the boiling point of acetone (58°C), would pave the way for developing a consolidated process with simplified and cost-effective recovery via condensation following gas fermentation.

scholarly journals Efficient Production of Acetic Acid from Nipa (Nypa fruticans) Sap by Moorella thermoacetica (f. Clostridium thermoaceticum)

2019 ◽  
Author(s):  
Dung Van Nguyen ◽  
Pinthep Sethapokin ◽  
Harifara Rabemanolontsoa ◽  
Eiji Minami ◽  
Haruo Kawamoto ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Oxalic Acid ◽  
Acid Catalyst ◽  
Cost Effective ◽  
Efficient Production ◽  
Acid Fermentation ◽  
Acid Yield ◽  
Moorella Thermoacetica ◽  
Nypa Fruticans ◽  
Hydrolysis Of

To valorize the underutilized nipa sap composed mainly of sucrose, glucose and fructose, acetic acid fermentation by Moorella thermoacetica was explored. Given that M. thermoacetica cannot directly metabolize sucrose, we evaluated various catalysts for the hydrolysis of this material. Oxalic acid and invertase exhibited high levels of activity towards the hydrolysis of the sucrose in nipa sap to glucose and fructose. Although these two methods consumed similar levels of energy for the hydrolysis of sucrose, oxalic acid was found to be more cost-effective. Nipa saps hydrolyzed by these two catalysts were also fermented by M. thermoacetica. The results revealed that the two hydrolyzed sap mixtures gave 10.0 g/L of acetic acid from the 10.2 g/L of substrate sugars in nipa sap. Notably, the results showed that the oxalic acid catalyst was also fermented to acetic acid, which avoided the need to remove the catalyst from the product stream. Taken together, these results show that oxalic acid hydrolysis is superior to enzymatic hydrolysis for the pretreatment of nipa sap. The acetic acid yield achieved in this study corresponds to a conversion efficiency of 98%, which is about 3.6 times higher than that achieved using the traditional methods. The process developed in this study therefore has high potential as a green biorefinery process for the efficient conversion of sucrose-containing nipa sap to bio-derived acetic acid.

scholarly journals Presence of Acetyl Coenzyme A (CoA) Carboxylase and Propionyl-CoA Carboxylase in Autotrophic Crenarchaeota and Indication for Operation of a 3-Hydroxypropionate Cycle in Autotrophic Carbon Fixation

1999 ◽  
Vol 181 (4) ◽  
pp. 1088-1098 ◽  
Author(s):  
Castor Menendez ◽  
Zsuzsa Bauer ◽  
Harald Huber ◽  
Nasser Gad’on ◽  
Karl-Otto Stetter ◽  
...  
Keyword(s):  
Phosphoenolpyruvate Carboxylase ◽  
Carbon Fixation ◽  
Coenzyme A ◽  
Autotrophic Growth ◽  
Acetyl Coa Carboxylase ◽  
Acetyl Coa ◽  
Carboxylase Activity ◽  
Acetyl Coenzyme A ◽  
Acetyl Coenzyme

ABSTRACT The pathway of autotrophic CO2 fixation was studied in the phototrophic bacterium Chloroflexus aurantiacus and in the aerobic thermoacidophilic archaeon Metallosphaera sedula. In both organisms, none of the key enzymes of the reductive pentose phosphate cycle, the reductive citric acid cycle, and the reductive acetyl coenzyme A (acetyl-CoA) pathway were detectable. However, cells contained the biotin-dependent acetyl-CoA carboxylase and propionyl-CoA carboxylase as well as phosphoenolpyruvate carboxylase. The specific enzyme activities of the carboxylases were high enough to explain the autotrophic growth rate via the 3-hydroxypropionate cycle. Extracts catalyzed the CO2-, MgATP-, and NADPH-dependent conversion of acetyl-CoA to 3-hydroxypropionate via malonyl-CoA and the conversion of this intermediate to succinate via propionyl-CoA. The labelled intermediates were detected in vitro with either 14CO2 or [14C]acetyl-CoA as precursor. These reactions are part of the 3-hydroxypropionate cycle, the autotrophic pathway proposed forC. aurantiacus. The investigation was extended to the autotrophic archaea Sulfolobus metallicus andAcidianus infernus, which showed acetyl-CoA and propionyl-CoA carboxylase activities in extracts of autotrophically grown cells. Acetyl-CoA carboxylase activity is unexpected in archaea since they do not contain fatty acids in their membranes. These aerobic archaea, as well as C. aurantiacus, were screened for biotin-containing proteins by the avidin-peroxidase test. They contained large amounts of a small biotin-carrying protein, which is most likely part of the acetyl-CoA and propionyl-CoA carboxylases. Other archaea reported to use one of the other known autotrophic pathways lacked such small biotin-containing proteins. These findings suggest that the aerobic autotrophic archaea M. sedula,S. metallicus, and A. infernus use a yet-to-be-defined 3-hydroxypropionate cycle for their autotrophic growth. Acetyl-CoA carboxylase and propionyl-CoA carboxylase are proposed to be the main CO2 fixation enzymes, and phosphoenolpyruvate carboxylase may have an anaplerotic function. The results also provide further support for the occurrence of the 3-hydroxypropionate cycle in C. aurantiacus.

scholarly journals Efficient Production of Acetic Acid from Nipa (Nypa fruticans) Sap by Moorella thermoacetica (f. Clostridium thermoaceticum)

2019 ◽  
Author(s):  
Dung Van Nguyen ◽  
Pinthep Sethapokin ◽  
Harifara Rabemanolontsoa ◽  
Eiji Minami ◽  
Haruo Kawamoto ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Oxalic Acid ◽  
Acid Catalyst ◽  
Cost Effective ◽  
Efficient Production ◽  
Acid Fermentation ◽  
Acid Yield ◽  
Moorella Thermoacetica ◽  
Nypa Fruticans ◽  
Hydrolysis Of

To valorize the underutilized nipa sap composed mainly of sucrose, glucose and fructose, acetic acid fermentation by Moorella thermoacetica was explored. Given that M. thermoacetica cannot directly metabolize sucrose, we evaluated various catalysts for the hydrolysis of this material. Oxalic acid and invertase exhibited high levels of activity towards the hydrolysis of the sucrose in nipa sap to glucose and fructose. Although these two methods consumed similar levels of energy for the hydrolysis of sucrose, oxalic acid was found to be more cost-effective. Nipa saps hydrolyzed by these two catalysts were also fermented by M. thermoacetica. The results revealed that the two hydrolyzed sap mixtures gave 10.0 g/L of acetic acid from the 10.2 g/L of substrate sugars in nipa sap. Notably, the results showed that the oxalic acid catalyst was also fermented to acetic acid, which avoided the need to remove the catalyst from the product stream. Taken together, these results show that oxalic acid hydrolysis is superior to enzymatic hydrolysis for the pretreatment of nipa sap. The acetic acid yield achieved in this study corresponds to a conversion efficiency of 98%, which is about 3.6 times higher than that achieved using the traditional methods. The process developed in this study therefore has high potential as a green biorefinery process for the efficient conversion of sucrose-containing nipa sap to bio-derived acetic acid.

scholarly journals Engineering of Primary Carbohydrate Metabolism for Increased Production of Actinorhodin in Streptomyces coelicolor

2006 ◽  
Vol 72 (11) ◽  
pp. 7132-7139 ◽  
Author(s):  
Yong-Gu Ryu ◽  
Michael J. Butler ◽  
Keith F. Chater ◽  
Kye Joon Lee
Keyword(s):  
Carbohydrate Metabolism ◽  
Carbon Metabolism ◽  
Carbon Flux ◽  
Streptomyces Coelicolor ◽  
Central Carbon Metabolism ◽  
Acetyl Coenzyme A ◽  
Central Carbon ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Acetyl Coenzyme A Carboxylase ◽  
Central Carbohydrate Metabolism

ABSTRACT The objectives of the current studies were to determine the roles of key enzymes in central carbon metabolism in the context of increased production of antibiotics in Streptomyces coelicolor. Genes for glucose-6-phosphate dehydrogenase and phosphoglucomutase (Pgm) were deleted and those for the acetyl coenzyme A carboxylase (ACCase) were overexpressed. Under the conditions tested, glucose-6-phosphate dehydrogenase encoded by zwf2 plays a more important role than that encoded by zwf1 in determining the carbon flux to actinorhodin (Act), while the function of Pgm encoded by SCO7443 is not clearly understood. The pgm-deleted mutant unexpectedly produced abundant glycogen but was impaired in Act production, the exact reverse of what had been anticipated. Overexpression of the ACCase resulted in more rapid utilization of glucose and sharply increased the efficiency of its conversion to Act. From the current experiments, it is concluded that carbon storage metabolism plays a significant role in precursor supply for Act production and that manipulation of central carbohydrate metabolism can lead to an increased production of Act in S. coelicolor.

scholarly journals Tolerance and Metabolic Response of Acetogenic Bacteria toward Oxygen

2002 ◽  
Vol 68 (2) ◽  
pp. 1005-1009 ◽  
Author(s):  
Arno Karnholz ◽  
Kirsten K�sel ◽  
Anita G��ner ◽  
Andreas Schramm ◽  
Harold L. Drake
Keyword(s):  
Metabolic Response ◽  
Nadh Oxidase ◽  
Lag Phase ◽  
Acetobacterium Woodii ◽  
Acetyl Coenzyme A ◽  
Moorella Thermoacetica ◽  
Cell Extracts ◽  
Low Concentrations ◽  
Acetogenic Bacteria ◽  
Thermoanaerobacter Kivui

ABSTRACT The acetogens Sporomusa silvacetica, Moorella thermoacetica, Clostridium magnum, Acetobacterium woodii, and Thermoanaerobacter kivui (i) grew in both semisolid and liquid cultivation media containing O2 and (ii) consumed small amounts of O2. Low concentrations of O2 caused a lag phase in growth but did not alter the ability of these acetogens to synthesize acetate via the acetyl coenzyme A pathway. Cell extracts of S. silvacetica, M. thermoacetica, and C. magnum contained peroxidase and NADH oxidase activities; catalase and superoxide dismutase activities were not detected.

scholarly journals Efficient Production of Acetic Acid from Nipa (Nypa fruticans) Sap by Moorella thermoacetica (f. Clostridium thermoaceticum)

2019 ◽  
Author(s):  
Dung Van Nguyen ◽  
Pinthep Sethapokin ◽  
Harifara Rabemanolontsoa ◽  
Eiji Minami ◽  
Haruo Kawamoto ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Oxalic Acid ◽  
Acid Catalyst ◽  
Cost Effective ◽  
Efficient Production ◽  
Acid Fermentation ◽  
Acid Yield ◽  
Moorella Thermoacetica ◽  
Nypa Fruticans ◽  
Hydrolysis Of

To valorize the underutilized nipa sap composed mainly of sucrose, glucose and fructose, acetic acid fermentation by Moorella thermoacetica was explored. Given that M. thermoacetica cannot directly metabolize sucrose, we evaluated various catalysts for the hydrolysis of this material. Oxalic acid and invertase exhibited high levels of activity towards the hydrolysis of the sucrose in nipa sap to glucose and fructose. Although these two methods consumed similar levels of energy for the hydrolysis of sucrose, oxalic acid was found to be more cost-effective. Nipa saps hydrolyzed by these two catalysts were also fermented by M. thermoacetica. The results revealed that the two hydrolyzed sap mixtures gave 10.0 g/L of acetic acid from the 10.2 g/L of substrate sugars in nipa sap. Notably, the results showed that the oxalic acid catalyst was also fermented to acetic acid, which avoided the need to remove the catalyst from the product stream. Taken together, these results show that oxalic acid hydrolysis is superior to enzymatic hydrolysis for the pretreatment of nipa sap. The acetic acid yield achieved in this study corresponds to a conversion efficiency of 98%, which is about 3.6 times higher than that achieved using the traditional methods. The process developed in this study therefore has high potential as a green biorefinery process for the efficient conversion of sucrose-containing nipa sap to bio-derived acetic acid.

scholarly journals Production of Biodegradable Polymer From Agro-Wastes in Alcaligenes sp. and Pseudomonas sp.

2021 ◽  
Author(s):  
R.Z. Sayyed ◽  
S. S. Shaikh ◽  
S. J. Wani ◽  
Md Tabish Rehman ◽  
Mohamed F. Alajmi ◽  
...  
Keyword(s):  
Rice Straw ◽  
Vegetable Oils ◽  
Large Scale ◽  
Low Cost ◽  
Mass Medium ◽  
Cell Mass ◽  
Cost Effective ◽  
Alcaligenes Faecalis ◽  
Pseudomonas Sp ◽  
Dry Cell

The present study was aimed to evaluate the suitability of agro-wastes and crude vegetable oils for the cost effective production of poly-β-hydroxybutyrate (PHB), to evaluate growth kinetics and PHB production in Alcaligenes faecalis RZS4 and Pseudomonas sp. RZS1 with these carbon substrates and to study the biodegradation of PHB accumulated by these cultures. Alcaligenes faecalis RZS4 and Pseudomonas sp. RZS1 accumulate higher amounts of PHB corn (79.90% of dry cell mass) and rice straw (66.22% of dry cell mass) medium respectively. The kinetic model suggests that the Pseudomonas sp. RZS1 follows the Monod model more closely than A. faecalis RZS4. Both the cultures degrade their own PHB extract under the influence of PHB depolymerase. Corn waste and rice straw appear as the best and cost-effective substrates for the sustainable production of PHB from Alcaligenes faecalis RZS4 and Pseudomonas sp. RZS1. The biopolymer accumulated by these organisms is biodegradable in nature. The agro-wastes and crude vegetable oils are good and low cost sources of nutrients for the growth and production of PHN and other metabolites. Their use would lower the production cost of PHN and the low cost production will reduce the sailing price of PHB based products. This would promote the large scale commercialization and popularization of PHB as ecofriendly bioplastic/biopolymer.

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