• Journal of Mushroom
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• v.14 no.1
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• pp.21-26
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• 2016

The mannanase-producing bacteria, designated YJ17, was isolated from spent mushroom (Flammulina velutipes) substrates. The isolate YJ17 was a facultative anaerobic and was grown at temperatures ranging from $20^{\circ}C$ to $50^{\circ}C$ with an optimal temperature of $40^{\circ}C$. The DNA G+C content of the YJ17 was 44 mol%. The major fatty acids were anteiso-15:0 (38.9%), 17:0 (7.6%), and iso-15:0 (36.5%). The 16S rRNA gene sequence similarity between the isolate YJ17 and other Bacillus strains was from 98% to 99%. In the phylogenetic analysis based on these sequences, the isolate YJ17 and Bacillus amyloliquefaciens clustered within a group together and separated from other species of Bacillus. Based on the physiological and molecular properties, the isolate YJ17 was classified within the genus Bacillus as B. amyloliquefaciens YJ17. The optimal pH and temperature for mannanase activity of B. amyloliquefaciens YJ17 were pH 7.0 and $50^{\circ}C$, respectively.

• Microbiology and Biotechnology Letters
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• v.29 no.4
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• pp.201-205
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• 2001

A bacteria strain producing extracellular $\beta$-mannanase was isolated from soil and was identified as Aeromonas sp. A genomic DNA library constructed from Aeromonas, sp that secrets a $\beta$-mannanase was screened for mannan hydrolytic acticity. Recombinant $\beta$-mannanase activity was detercted on the basis of the clear zones around Escherichia coli colonies grown on a LB medium supplemented locust bean gum, EcoRI restriction analysis of plasmid prepared from recombinant E. coli which showed a $\beta$-mannanase activity revealed 10 kb DNA insert, The optimum pH and temperature for the activity of reconmbinant $\beta$-mannanase were 6.0 and $50^{\circ}C$ respectively and were identical to those of the native enzyme.

• Microbiology and Biotechnology Letters
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• v.31 no.1
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• pp.57-62
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• 2003

A bacteria strain producing extracellular $\beta$-mannanase was isolated from soil and was identified as Bacillus subtilis by 16S rRNA sequence comparison and biochemical determinations. The optimum pH and temperature for the $\beta$-mannanase activity were 5.0 and 5.5$^{\circ}C$, respectively. The zymogram technique revealed a single protein band exhibiting $\beta$-mannanase activity from the culture supernatant. The molecular mass of the enzyme was estimated at approximately 130 kDa. The addition of 0.5% lactose or 0.5% locust bean gum to the LB medium caused to Increase significantly the $\beta$-mannanase productivity from Bacillus subtilis JS-1. The cells grown on LB medium supplemented with lactose produced maximal enzyme activity at the stationary phase. In contrast to this, the $\beta$-mannanase was induced at the logarithmic phase from the cells grown on LB medium supplemented with locust bean gum. The discrepancy in induction times suggests that $\beta$-mannanase was induced by different induction mechanisms depending on the carbon sources in Bacillus subtilis JS-1 .

• Journal of Life Science
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• v.26 no.10
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• pp.1113-1120
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• 2016

Two bacterial strains producing extracellular man nanase were isolated from doenjang, a traditionally fermented soybean paste in Korea. The isolates, WL-6 and WL-11, were identified as Bacillus subtiis on the basis of their 16S rRNA gene sequences, morphological, and biochemical properties. Two genes encoding the mannanase of both B. subtilis WL-6 and B. subtilis WL-11 were each cloned into Escherichia coli, and their nucleotide sequences were determined. Both mannanase genes consisted of 1,086 nucleotides, encoding polypeptides of 362 amino acid residues. The deduced amino acid sequences of the two WL-6 and WL-11 mannanases, designated Man6 and Man11, respectively, differed from each other by eight amino acid residues, and they were highly homologous to those of mannanases belonging to the glycosyl hydrolase family 26. The 26 amino acid stretch in the N-terminus of Man6 and Man11 was a predicted signal peptide. Both Man6 and Man11 were localized at the level of 94–95% in an intracellular fraction of recombinant E. coli cells. The enzymes hydrolyzed both locust bean gum and mannooligosaccharides, including mannotriose, mannotetraose, mannopentaose, and mannohexaose, forming mannobiose and mannotriose as predominant products. The optimal reaction conditions were 55°C and pH 6.0 for Man6, and 60°C and pH 5.5 for Man11. Man11 was more stable than Man6 at high temperatures.

• Journal of Life Science
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• v.19 no.12
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• pp.1724-1730
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• 2009

The mannanase-producing bacteria, designated CS47, was isolated from the fresh feces of three horses (from a farm in Jinju National University). The isolate CS47 was facultatively anaerobic and grew at temperatures ranging from $20^{\circ}C$ to $50^{\circ}C$ with an optimal temperature of $38^{\circ}C$. The DNA G+C content of the isolate CS47 was 44 mlo%. The major fatty acids were anteiso-15:0 (39.6%), 17:0 (7.6%), and iso-15:0 (37.8%). The 16S rRNA gene sequence similarity between the isolate CS47 and other Bacillus strains varied from 93% to 98%. In the phylogenetic analysis based on these sequences, the isolate CS47 and Bacillus amyloliquefaciens clustered within a group and separated from other species of Bacillus. Based on the physiological and molecular properties, the isolate CS47 was classified within the genus Bacillus as Bacillus amyloliquefaciens CS47. The optimal pH and temperature for mannanase activity of B. amyloliquefaciens CS47 were pH 6.0 and $50^{\circ}C$, respectively. The thermal stability of mannanase from B. amyloliquefaciens CS47 is valuable when using this enzyme in industrial application.