Biological process for coproduction of hydrogen and thermophilic enzymes during CO fermentation.

To develop a thermophilic cell factory system that uses CO gas, we attempted to engineer a hyperthermophilic carboxydotrophic hydrogenic archaeon Thermococcus onnurineus NA1 to be capable of producing thermophilic enzymes along with hydrogen (H). The mutant strains 156T-AM and 156T-POL were constructed to have another copy of a gene encoding α-amylase or DNA polymerase, respectively, and exhibited growth rates and H production rates distinct from those of the parental strain, 156T, in gas fermentation using 100% CO or coal-gasified syngas. Purified α-amylase displayed starch-hydrolyzing activity, and whole-cell extracts of 156T-AM showed saccharifying activity for potato peel waste.

Efficient production of 1,3-propanediol from crude glycerol by repeated fed-batch fermentation strategy of a lactate and 2,3-butanediol deficient mutant of Klebsiella pneumoniae.

Background: 1,3-Propanediol (1,3-PDO) is important building blocks for the bio-based chemical industry, Klebsiella pneumoniae can be an attractive candidate for their production. However, 1,3-PDO production is high but productivity is generally low by K. pneumoniae.

A biological process effective for the conversion of CO-containing industrial waste gas to acetate.

Acetogens have often been observed to be inhibited by CO above an inhibition threshold concentration. In this study, a two-stage culture consisting of carboxydotrophic archaea and homoacetogenic bacteria is found to be effective in converting industrial waste gas derived from a steel mill process. In the first stage, Thermococcus onnurineus could grow on the Linz-Donawitz converter gas (LDG) containing ca.

Adaptive engineering of a hyperthermophilic archaeon on CO and discovering the underlying mechanism by multi-omics analysis.

The hyperthermophilic archaeon Thermococcus onnurineus NA1 can grow and produce H2 on carbon monoxide (CO) and its H2 production rates have been improved through metabolic engineering. In this study, we applied adaptive evolution to enhance H2 productivity. After over 150 serial transfers onto CO medium, cell density, CO consumption rate and H2 production rate increased.

Enhanced production of 2,3-butanediol by a genetically engineered Bacillus sp. BRC1 using a hydrolysate of empty palm fruit bunches.

A Bacillus species that produces 2,3-butanediol (2,3-BD), termed BRC1, was newly isolated, and a 2,3-BD dehydrogenase (Bdh) from this species was identified and characterized at the molecular and biochemical level. Sequence analysis revealed that Bdh is homologous to D-2,3-BD dehydrogenases. An analysis of the enzymatic properties of Bdh overexpressed in Escherichia coli confirmed the molecular results, showing preferred activity toward D-2,3-BD.

Identification and characterization of a short-chain acyl dehydrogenase from Klebsiella pneumoniae and its application for high-level production of L-2,3-butanediol.

Klebsiella pneumoniae synthesize large amounts of L-2,3-butanediol (L-2,3-BD), but the underlying mechanism has been unknown. In this study, we provide the first identification and characterization of an L-2,3-BD dehydrogenase from K. pneumoniae, demonstrating its reductive activities toward diacetyl and acetoin, and oxidative activity toward L-2,3-BD.

Enhancement of 1,3-propanediol production by expression of pyruvate decarboxylase and aldehyde dehydrogenase from Zymomonas mobilis in the acetolactate-synthase-deficient mutant of Klebsiella pneumoniae.

The acetolactate synthase (als)-deficient mutant of Klebsiella pneumoniae fails to produce 1,3-propanediol (1,3-PD) or 2,3-butanediol (2,3-BD), and is defective in glycerol metabolism. In an effort to recover production of the industrially valuable 1,3-PD, we introduced the Zymomonas mobilis pyruvate decarboxylase (pdc) and aldehyde dehydrogenase (aldB) genes into the als-deficient mutant to activate the conversion of pyruvate to ethanol. Heterologous expression of pdc and aldB efficiently recovered glycerol metabolism in the 2,3-BD synthesis-defective mutant, enhancing the production of 1,3-PD by preventing the accumulation of pyruvate.

Production of 2-butanol from crude glycerol by a genetically-engineered Klebsiella pneumoniae strain.

Klebsiella pneumoniae was engineered to produce 2-butanol from crude glycerol as a sole carbon source by expressing acetolactate synthase (ilvIH), keto-acid reducto-isomerase (ilvC) and dihydroxy-acid dehydratase (ilvD) from K. pneumoniae, and α-ketoisovalerate decarboxylase (kivd) and alcohol dehydrogenase (adhA) from Lactococcus lactis. Engineered K.

The isolation and characterization of simultaneous saccharification and fermentation microorganisms for Laminaria japonica utilization.

Brown seaweed contains various carbohydrates, such as alginate, laminaran, and mannitol, therefore ethanol fermentation was attempted with Nuruk and a mixed culture that included Laminaria japonica. Nuruk is used to make Korean traditional alcohol. In the research, four microorganisms that produced ethanol and had the ability to achieve alginate degradation were obtained on the L.