A cellulose-producing acetic acid bacterium,Acetobacter xylinum KU-1, abundantly produces an extracellularendo-beta-glucanase (EC 3.2.1.4) in the culture broth. The enzyme was purifiedto homogeneity by DEAE- and CM- Toyopearl 650M ion-exchange chromatography,Butyl-Toyopearl 650M hydrophobic chromatography, and Toyopearl HW-50 gelfiltration. The purified enzyme showed the maximum activity at pH 5 and50°C: it was stable up to 50°C at pH 5, activated by Co2+, andcompetitively inhibited by Hg2+; the apparentKi was 7 &mgr;M. The molecular weight of the enzyme wasdetermined to be about 39,000 by sodium dodesyl sulfate/polyacrylamide gelelectrophoresis, and about 41,000 by Toyopearl HW-50 gel filtration; theenzyme is monomeric. The enzyme hydrolyzed carboxymethylcellulose with anapparent Km of 30 mg/ml and Vmax of 1.2&mgr;M/min. It hydrolyzed cellohexaose to cellobiose, cellotriose andcellotetraose, and also cellopentaose to cellobiose and cellotriose, but didnot act on cellobiose, cellotriose, or cellotetraose.
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http://dx.doi.org/10.1007/s002849900187 | DOI Listing |
Mar Drugs
December 2024
Jeju Bio Research Center, Korea Institute of Ocean Science & Technology, Jeju-si 63349, Republic of Korea.
In this study, we report the molecular and enzymatic characterisation of Spg103, a novel bifunctional β-glucanase from the marine bacterium sp. J103. Recombinant Spg103 (rSpg103) functioned optimally at 60 °C and pH 6.
View Article and Find Full Text PDFMicrob Cell Fact
November 2024
Laboratory of Enzymology and Molecular Biology of Microorganisms (LEBIMO), Department of Biochemistry and Tissue Biology, Institute of Biology, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, 13083-862, Brazil.
Background: Fermentation of sugars derived from plant biomass feedstock is crucial for sustainability. Hence, utilizing customized enzymatic cocktails to obtain oligosaccharides instead of monomers is an alternative fermentation strategy to produce prebiotics, cosmetics, and biofuels. This study developed an engineered strain of Aspergillus niger producing a tailored cellulolytic cocktail capable of partially degrading sugarcane straw to yield cellooligosaccharides.
View Article and Find Full Text PDFArch Microbiol
September 2024
Laboratory of Molecular Biotechnology of Eukaryotes, Center of Biotechnology of Sfax (CBS), University of Sfax, Sfax, Tunisia.
Cello-oligosaccharides (COS) become a new type of functional oligosaccharides. COS transglycosylation reactions were studied to enhance COS yield production. Seeking the ability of the free form of Fusarium solani β-glucosidase (FBgl1) to synthesize COS under low substrate concentrations, we found out that this biocatalyst initiates this reaction with only 1 g/L of cellobiose, giving rise to the formation of cellotriose.
View Article and Find Full Text PDFmSphere
August 2024
TBI, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France.
In ruminants, the rumen is a specialized stomach that is adapted to the breakdown of plant-derived complex polysaccharides through the coordinated activities of a diverse microbial community. Bacteroidota is a major phylum in this bovine rumen microbiota. They contain several clusters of genes called polysaccharide utilization loci (PULs) that encode proteins working in concert to capture, degrade, and transport polysaccharides.
View Article and Find Full Text PDFAnim Biosci
September 2024
Jilin Key Laboratory for Molecular Biology of Special Economic Animals, Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Changchun 130112, China.
Objective: This study aimed to identify and characterize a novel endo-β-glucanase, IDSGLUC9-4, from the rumen metatranscriptome of Hu sheep.
Methods: A novel endo-β-glucanase, IDSGLUC9-4, was heterologously expressed in Escherichia coli and biochemically characterized. The optimal temperature and pH of recombinant IDSGLUC9-4 were determined.
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