Please wait a moment until all data is loaded. This message will disappear when all data is loaded.
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
biotechnology
the reaction specificity of acetolactate synthase from Thermus thermophilus can be redirected to catalyze acetaldehyde formation to develop a thermophilic pyruvate decarboxylase. Quadruple mutant Y35N/K139R/V172A/H474R shows 3.1fold higher acetaldehyde-forming activity than the wild-type mainly because of H474R amino acid substitution, which likely generates two new hydrogen bonds near the thiamine diphosphate-binding site
biotechnology
-
the reaction specificity of acetolactate synthase from Thermus thermophilus can be redirected to catalyze acetaldehyde formation to develop a thermophilic pyruvate decarboxylase. Quadruple mutant Y35N/K139R/V172A/H474R shows 3.1fold higher acetaldehyde-forming activity than the wild-type mainly because of H474R amino acid substitution, which likely generates two new hydrogen bonds near the thiamine diphosphate-binding site
-
synthesis
-
synthesis of (R)-phenylacetylcarbinol from cheap substrates in an aqueous reaction system by W392M mutant PDC, alternative strategy to the current fermentative process free of any unwanted by-product
synthesis
-
Candida utilis PDC is a stable and high productivity enzyme for the production (R)-phenylacetylcarbinol, a pharmaceutical precursor
synthesis
-
engineered enzyme mutants are useful for synthesis of both enantiomers of alpha-ketols and acetolactates with good enantiomeric excess, overview
synthesis
-
PDC is useful for the production (R)-phenylacetylcarbinol, a pharmaceutical precursor
synthesis
-
PDC is useful for the production (R)-phenylacetylcarbinol, a pharmaceutical precursor
synthesis
-
PDC is useful for the production (R)-phenylacetylcarbinol, a pharmaceutical precursor
synthesis
-
the enzyme is useful in ethanol production in bacterial coupled systems, overview
synthesis
alpha-ketoisovalerate decarboxylase Kivd from Lactococcus lactis combined with alcohol dehydrogenase Adh3 from Zymomonas mobilis are the optimum candidates for 3-methyl-1-butanol production in Corynebacterium glutamicum. The recombinant strain produces 0.182 g/l of 3-methyl-1-butanol and 0.144 g/l of isobutanol after 12 h of incubation. Further inactivation of the E1 subunit of pyruvate dehydrogenase complex gene (aceE) and lactic dehydrogenase gene (ldh) improves the 3-methyl-1-butanol titer to 0.497 g/l after 12 h of incubation
synthesis
comparison of relevant properties for isobutanol production of Saccharomyces cerevisiae Aro10 and Lactococcus lactis KivD and KdcA genes. Activity in cell extracts reveals a superior Vmax/Km ratio of KdcA for alpha-ketoisovalerate and a wide range of linear and branched-chain 2-oxo acids. KdcA also shows the highest activity with pyruvate which, in engineered strains, can contribute to formation of ethanol as a by-product. During oxygen-limited incubation in the presence of glucose, strains expressing kdcA or kivD show a ca. twofold higher in vivo rate of conversion of alpha-ketoisovalerate into isobutanol than an Aro10-expressing strain. Cell extracts from cultures grown on different nitrogen sources reveal increased activity of constitutively expressed KdcA after growth on both valine and phenylalanine, while KivD and Aro10 activity is only increased after growth on phenylalanine
synthesis
construction of a bypassed pyruvate decarboxylation pathway, through which pyruvate can be converted to acetyl-CoA, by using a coupled enzyme system consisting of pyruvate decarboxylase from Acetobacter pasteurianus and the CoA-acylating aldehyde dehydrogenase from Thermus thermophilus. A cofactor-balanced and CoA-recycling synthetic pathway for N-acetylglutamate production is designed by coupling the bypassed pathway with the glutamate dehydrogenase from Thermus thermophilus and N-acetylglutamate synthase from Thermotoga maritima. N-Acetylglutamate can be produced from an equimolar mixture of pyruvate and alpha-ketoglutarate with a molar yield of 55% through the synthetic pathway consisting of a mixture of four recombinant Escherichia coli strains having either one of the thermostable enzymes. The overall recycling number of CoA is 27
synthesis
construction of a bypassed pyruvate decarboxylation pathway, through which pyruvate can be converted to acetyl-CoA. The coupled enzyme system consists of pyruvate decarboxylase from Acetobacter pasteurianus and the CoA-acylating aldehyde dehydrogenase from Thermus thermophilus. A cofactor-balanced and CoA-recycling synthetic pathway for N-acetylglutamate production is established by coupling the bypassed pathway with the glutamate dehydrogenase from Thermus thermophilus and N-acetylglutamate synthase from Thermotoga maritima. N-Acetylglutamate can be produced from an equimolar mixture of pyruvate and alpha-ketoglutarate with a molar yield of 55% through the synthetic pathway consisting of a mixture of four recombinant Escherichia coli strains having either one of the thermostable enzymes. The overall recycling number of CoA is 27
synthesis
-
construction of isobutanol production systems by overexpression of effective 2-oxoacid decarboxylase KivD and combinatorial overexpression of valine biosynthetic enzymes in Saccharomyces cerevisiae D452-2. Isobutanol production by the engineered strain is assessed in micro-aerobic batch fermentations using glucose as a sole carbon source, leading to priduction of 93 mg/l isobutanol, which corresponds to a fourfold improvement as compared with the control strain. Isobutanol production is further enhanced to 151 mg/l by additional overexpression of acetolactate synthase Ilv2p, acetohydroxyacid reductoisomerase Ilv5p, and dihydroxyacid dehydratase Ilv3p in the cytosol
synthesis
engineering of Klebsiella pneumoniae to produce 2-butanol from crude glycerol as a sole carbon source by expressing acetolactate synthase (IlvIH), keto-acid reducto-isomerase (IlvC) and dihydroxyacid dehydratase (IlvD) from Klebsiella pneumoniae, and alpha-oxoisovalerate decarboxylase (Kivd) and alcohol dehydrogenase (AdhA) from Lactococcus lactis. The engineered strain produce 2-butanol (160 mg/l) from crude glycerol. Elimination of the 2,3-butanediol pathway by inactivating alpha-acetolactate decarboxylase (Adc) further improves the yield of 2-butanol from 160 to 320 mg/l
synthesis
enhancement of ethanol production capacity of Clostridium thermocellum by transferring pyruvate decarboxylase and alcohol dehydrogenase genes of the homoethanol pathway from Zymomonas mobilis. Both transferring pyruvate decarboxylase and alcohol dehydrogenase are functional in Clostridium thermocellum, but the presence of and alcohol dehydrogenase severely limits the growth of the recombinant strains, irrespective of the presence or absence of the pyruvate decarboxylase gene. The recombinant strain shows two-fold increase in pyruvate carboxylase activity and ethanol production when compared with the wild type strain
synthesis
-
expression of branched-chain alpha-oxo acid decarboxylase from Lactococcus lactis subsp. lactis KivD and alcohol dehydrogenase from Zymomonas mobilis AdhB in Escherichia coli for higher alcohol production. In LB medium, the resulting strain produces much more 3-methyl-1-butanol (104 mg/l) than isobutanol (24 mg/l). In 5 g/l glucose-containing medium, the production of two alcohols is similar, 156 and 161 mg/l for C4 (isobutanol) and C5 (3-methyl-1-butanol) alcohol, respectively. The increase of glucose content and the adding of alpha-keto acids facilitate the production of C4 and C5 alcohols. The enzyme activities of pure Kivd on alpha-ketoisovalerate and alpha-ketoisocaproate are 26.77 and 21.24 micromol/min and mg, respectively
synthesis
-
in order to increase production of isobutanol, 2-oxoacid decarboxylase (KDC) and alcohol dehydrogenase (ADH) are expressed in Saccharomyces cerevisiae to enhance the endogenous activity of the Ehrlich pathway. Overexpression Ilv2, which catalyzes the first step in the valine synthetic pathway, and deletion of the PDC1 gene encoding a major pyruvate decarboxylase alters the abundant ethanol flux via pyruvate. Along with modification of culture conditions, the isobutanol titer is elevated 13fold, from 11 mg/l to 143 mg/l, and the yield is 6.6 mg/g glucose
synthesis
-
modification of enzyme with the N-succinimide ester of an amylose glycylglycine adduct. Upon conjugation, the optimum temperature shifts from 35°C to 40°C, the conjugate shows higher resistance to heat treatment than the native enzyme
synthesis
Ralstonia eutropha H16 produces polyhydroxybutanoate as an intracellular carbon storage material. The excess carbon can be redirected in engineered strains from polyhydroxybutanoate storage to the production of isobutanol and 3-methyl-1-butanol (branched-chain higher alcohols). Strains of Ralstonia eutropha with isobutyraldehyde dehydrogenase activity, in combination with the overexpression of plasmid-borne, native branched-chain amino acid biosynthesis pathway genes and the overexpression of heterologous ketoisovalerate decarboxylase gene, are employed for the biosynthesis of isobutanol and 3-methyl-1-butanol. One mutant strain produces over 180 mg/l branched-chain alcohols in flask culture, and is significantly more tolerant of isobutanol toxicity than wild-type. After the elimination of genes ilvE, bkdAB, and aceE, the production titer improves to 270 mg/l isobutanol and 40 mg/l 3-methyl-1-butanol. Under semicontinuous flask cultivation, the strain grows and produces more than 14 g/l branched-chain alcohols over the duration of 50 days
synthesis
-
PDC is useful for the production (R)-phenylacetylcarbinol, a pharmaceutical precursor
-
synthesis
-
PDC is useful for the production (R)-phenylacetylcarbinol, a pharmaceutical precursor
-
synthesis
-
construction of isobutanol production systems by overexpression of effective 2-oxoacid decarboxylase KivD and combinatorial overexpression of valine biosynthetic enzymes in Saccharomyces cerevisiae D452-2. Isobutanol production by the engineered strain is assessed in micro-aerobic batch fermentations using glucose as a sole carbon source, leading to priduction of 93 mg/l isobutanol, which corresponds to a fourfold improvement as compared with the control strain. Isobutanol production is further enhanced to 151 mg/l by additional overexpression of acetolactate synthase Ilv2p, acetohydroxyacid reductoisomerase Ilv5p, and dihydroxyacid dehydratase Ilv3p in the cytosol
-
synthesis
-
expression of branched-chain alpha-oxo acid decarboxylase from Lactococcus lactis subsp. lactis KivD and alcohol dehydrogenase from Zymomonas mobilis AdhB in Escherichia coli for higher alcohol production. In LB medium, the resulting strain produces much more 3-methyl-1-butanol (104 mg/l) than isobutanol (24 mg/l). In 5 g/l glucose-containing medium, the production of two alcohols is similar, 156 and 161 mg/l for C4 (isobutanol) and C5 (3-methyl-1-butanol) alcohol, respectively. The increase of glucose content and the adding of alpha-keto acids facilitate the production of C4 and C5 alcohols. The enzyme activities of pure Kivd on alpha-ketoisovalerate and alpha-ketoisocaproate are 26.77 and 21.24 micromol/min and mg, respectively
-
synthesis
-
PDC is useful for the production (R)-phenylacetylcarbinol, a pharmaceutical precursor
-
synthesis
-
Candida utilis PDC is a stable and high productivity enzyme for the production (R)-phenylacetylcarbinol, a pharmaceutical precursor
-