The gdh and gdhr genes, encoding B(12)-dependent glycerol dehydratase (GDH) and glycerol dehydratase reactivase (GDHR), respectively, in Klebsiella pneumoniae, were cloned and expressed in E. coli. Part of the beta-subunit was lost during GDH purification when co-expressing alpha, beta and gamma subunit. This was overcome by fusing the beta-subunit to alpha- or gamma-subunit with/without the insertion of a linker peptide between the fusion moieties. The kinetic properties of the fusion enzymes were characterized and compared with wild type enzyme. The results demonstrated that the fusion protein GDHALB/C, constructed by linking the N-terminal of beta-subunit to the C-terminal of alpha subunit through a (Gly(4)Ser)(4) linker peptide, had the greatest catalytic activity. Similar to the wild-type enzyme, GDHALB/C underwent mechanism-based inactivation by glycerol during catalysis and could be reactivated by GDHR.
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http://dx.doi.org/10.1007/s10529-009-9911-x | DOI Listing |
Front Bioeng Biotechnol
November 2024
State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
1,3-Propanediol (1,3-PDO) is one of the important organic chemical materials and is widely used in polyester synthesis, and it also shows great potential in medicine, cosmetics, resins, and biodegradable plastics. So far, 1,3-PDO mainly comes from chemical synthesis. However, the by-products and the side effects during chemical synthesis of 1,3-PDO bring about serious damage to the environment.
View Article and Find Full Text PDFMicrobiome
September 2024
Department of Biological and Chemical Engineering, Aarhus University, Gustav Wieds Vej 10, 8000, Arhus, Denmark.
Background: Microbial pdu and cob-cbi-hem gene clusters encode the key enzyme glycerol/diol dehydratase (PduCDE), which mediates the transformation of dietary nutrients glycerol and 1,2-propanediol (1,2-PD) to a variety of metabolites, and enzymes for cobalamin synthesis, a co-factor and shared good of microbial communities. It was the aim of this study to relate pdu as a multipurpose functional trait to environmental conditions and microbial community composition. We collected fecal samples from wild animal species living in captivity with different gut physiology and diet (n = 55, in total 104 samples), determined occurrence and diversity of pdu and cob-cbi-hem using a novel approach combining metagenomics with quantification of metabolic and genetic biomarkers, and conducted in vitro fermentations to test for trait-based activity.
View Article and Find Full Text PDFAppl Environ Microbiol
August 2024
International Cooperation Base of Science and Technology Innovation on Forest Resource Biotechnology, Central South University of Forestry and Technology, Changsha, China.
Glycerol dehydratase is the key and rate-limiting enzyme in the 1,3-propanediol synthesis pathway of , which determined the producing rate and yield of 1,3-propanediol. However, the expression regulation mechanism of glycerol dehydratase gene remains poorly unknown. In this study, a histone-like nucleoid-structuring (H-NS) protein was identified and characterized as the positive transcription regulator for expression in 2e, which exhibited high tolerance against crude glycerol in our previous study.
View Article and Find Full Text PDFJ Agric Food Chem
February 2024
School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, Jiangsu, China.
Embracing the principles of sustainable development, the valorization of agrowastes into value-added chemicals has nowadays received significant attention worldwide. Herein, was metabolically rewired to convert cellulosic hydrolysate of corn stover into a key platform chemical, namely, 3-hydroxypropionic acid (3-HP). First, the heterologous pathways were introduced into by coexpressing glycerol-3-P dehydrogenase and glycerol-3-P phosphatase in both single and fusion (12) forms, making the strain capable of synthesizing glycerol from glucose.
View Article and Find Full Text PDFBiotechnol Biofuels Bioprod
November 2023
Hunan Provincial Key Laboratory of Forestry Biotechnology, Central South University of Forestry and Technology, Changsha, 410004, China.
Background: The direct bioconversion of crude glycerol, a byproduct of biodiesel production, into 1,3-propanediol by microbial fermentation constitutes a remarkably promising value-added applications. However, the low activity of glycerol dehydratase, which is the key and rate-limiting enzyme in the 1,3-propanediol synthetic pathway, caused by crude glycerol impurities is one of the main factors affecting the 1,3-propanediol yield. Hence, the exploration of glycerol dehydratase resources suitable for crude glycerol bioconversion is required for the development of 1,3-propanediol-producing engineered strains.
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