Microbial production of butanediol and acetoin has received increasing interest because of their diverse potential practical uses. Although both products are fermentative in nature, their optimal production requires a low level of oxygen. In this study, the use of a recombinant oxygen uptake system on production of these metabolites was investigated. Enterobacter aerogenes was transformed with a pUC8-based plasmid carrying the gene (vgb) encoding Vitreoscilla (bacterial)hemoglobin (VHb). The presence of vgb and production of VHb by this strain resulted in an increase in viability from 72 to 96 h in culture, but no overall increase in cell mass. Accumulation of the fermentation products acetoin and butanediol were enhanced (up to 83%) by the presence of vgb/VHb. This vgb/VHb related effect appears to be due to an increase of flux through the acetoin/butanediol pathway, but not at the expense of acid production.
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http://dx.doi.org/10.1007/s00449-004-0373-1 | DOI Listing |
Arch Biochem Biophys
November 2024
College of Life Sciences, Northwest University, 229 North Taibai Road, Xi'an, Shaanxi, 710069, China. Electronic address:
Acetolactate synthase (ALS) is an essential enzyme involved in the biosynthesis of platform chemicals acetoin and 2,3-butanediol in several microorganisms. In this study, we investigated the catalytic differences among three bacterial ALSs involved in the ligation of two molecules of pyruvate or 2-ketobutyrate. Based on the findings, we predicted three amino acid residues in each enzyme that caused a discrepancy in accordance with the multi-sequence alignment and molecular docking experiments: I398, A402, and T480 in Bacillus subtilis ALS; V400, Y404, and S482 in Listeria seleigeri serovar 1/2b ALS; and M394, H398, and G476 in Klebsiella pneumoniae ALS.
View Article and Find Full Text PDFMicrob Pathog
November 2024
Yildiz Technical University, Faculty of Arts and Sciences, Department of Molecular Biology and Genetics, Istanbul, Turkey. Electronic address:
During a study investigating possible probiotics from chicken gut microbiota, strains C1-4 and C2-3 were isolated and identified as members of the genus Ligilactobacillus. The strains formed a well-supported cluster with Ligilactobacillus salivarius and Ligilactobacillus hayatikensis in phylogenetic trees. Their genomes, sized 1.
View Article and Find Full Text PDFACS Synth Biol
November 2024
Thayer School of Engineering at Dartmouth College, Hanover, New Hampshire 03755, United States.
Genetic approaches have been traditionally used to understand microbial metabolism, but this process can be slow in nonmodel organisms due to limited genetic tools. An alternative approach is to study metabolism directly in the cell lysate. This avoids the need for genetic tools and is routinely used to study individual enzymatic reactions but is not generally used to study systems-level properties of metabolism.
View Article and Find Full Text PDFPrep Biochem Biotechnol
September 2024
Laboratório de Bioprocessos, Caxias do Sul, Universidade de Caxias do Sul (UCS), Instituto de Biotecnologia, Rio Grande do Sul, Brazil.
2,3-Butanediol (2,3-BD) is a highly valued building block, and optimizing its production by fermentation, particularly with crude glycerol, is crucial. is a key microorganism for this process; however, there are limited studies addressing the inhibition effects of products and by-products on 2,3-BD production. This study investigates these inhibition effects to maximize 2,3-BD production.
View Article and Find Full Text PDFInt J Food Microbiol
December 2024
Central Research Institute, Dr. Chung's Food Co., Ltd., Cheongju-si, Republic of Korea. Electronic address:
Lactic acid bacteria are commonly used in plant-based fermentation to reduce off-flavor and improve sensory characteristics. However, there have been few studies on Latilactobacillus sakei for plant-based yogurt fermentation and, particularly, its metabolic features at the genomic level remain unclear. This study aims to analyze the fermentation characteristics of the L.
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