• Journal of Microbiology and Biotechnology
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• v.14 no.4
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• pp.751-758
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• 2004

The NCS(Non-Cariogenicity Sugar) from Bacillus sp. S-1013 was purified by cold acetone and methanol precipitation, and DEAE-cellulose ion-exchange and Sephadex G-100 column chromatographies, to yield an amorphous yellow syrup. The melting point and $[\alpha]_D^{20}$ were 155-$157^{\circ}C$ and +53, respectively. Instrumental analyses such as FT-IR, $^1H-NMR, and ^{13}C-NMR$ showed that the NCS contained an O-H group, C-H, C=O, $NH_2$, anomeric carbon, anomeric proton, N-acetylgalactose, fucose, and neuramic acid, thus, the NCS was determined to be a trisaccharide of Fuc($1\longrightarrow4$)GalNAc($2\longrightarrow6$) NeuAc.

• Microbiology and Biotechnology Letters
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• v.34 no.3
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• pp.235-243
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• 2006

The study was performed to identification of producing microbe Non-Cariogenicity Sugar (NCS; Fuc($1{\to}4$) gaINAc($2{\to}6$)NeuAc) with anti-caries activity, and to optimization of production condition. A typical strain which produced the NCS was identified alkalophilic Bacillus sp. S-1013 through the results of morphological, biochemical and chemotaxonomic characteristics and 16S rDNA sequencing. The optimal medium composition for the maximal production of the NCS from alkalophilic Bacillus sp. S-1013 was as follow: soluble starch 30 g, dextrin 15 g, yeast extract 5 g, peptone 10 g, $K_{2}HPO_4$ 2 g in a liter of distilled water. Optimal temperature and pH were 25 and 11.0, respectively. The highest production of NCS was shown 60 hrs cultivation using the optimal medium, and then NCS productivity and dry cell weight of culture broth increased 4.24 and 2.67 time than initial medium, respectively.

• Journal of Microbiology and Biotechnology
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• v.14 no.4
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• pp.759-765
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• 2004

The NCS inhibited the activity of glucosyltransferase which was produced by Streptococcus mutans JC-2, and the rate of inhibition at $100\muM<$ and $200\muM$ were 74.0% and 99.8%, respectively. It was stable in alkali condition, but unstable in acid condition. It was also stable up to $80^{\circ}C$. The kinetic study of the inhibition by NCS was carried out by Lineweaver-Burk plot and Dixon plot. It was non-competitive inhibition, determined by the two plots and $K_i$ and $K_i$ values were $15\muM$ and $19.3\muM$ respectively. The NCS did not show cytotoxicity against human gingival cells at $K_i$ ($15\muM$, $150\muM$, $1,500\mu$ M) concentrations. It had less cytotoxicity than chlohexidin, which has usually been used as the agent of anticaries. To evaluate the industrial applicability of the NCS, human pluck tooth was used. The inhibitory rates of tooth calcification and calcium ion elution by the NCS were 41 % and 2.5 times, respectively. These results suggested that NCS from Bacillus sp. S-1013 is an efficient anticaries agent.

• Journal of Life Science
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• v.25 no.2
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• pp.180-188
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• 2015

The bacterial strain isolated from Kimchi showed antibacterial activity against Micrococcus luteus IAM 1056. The selected strain was identified as Lactococcus lactis by 16S rRNA nucleotide sequence analysis and named as Lactococcus sp. KD 28. The treatment of culture supernatant with proteinase K removed antibacterial activity, indicating its proteinaceous nature, a bacteriocin. This bacteriocin was sensitive to hydrolytic enzymes such as ${\alpha}$-chymotrypsion, trypsin, proteinase K, lipase, ${\alpha}$-amylase and subtilisin A. The bacteriocin was highly thermostable and resistant to heating at $80^{\circ}C$ for up to an hour but 50 % of the total activity was remained at $100^{\circ}C$ for 30 min. The pH range from 2.0 to 8.0 had no effect on bacteriocin activity and it was not affected by solvents such as acetonitrile, isopropanol, methanol, chloroform and acetone up to 50% concentration. The bacteriocin showed antibacterial activity against M. luteus IAM 1056, Lactobacillus delbrueckii subsp. lactis KCTC 1058, Enterococcus faecium KCTC 3095, Bacillus cereus KCTC 1013, B. subtilis KCTC 1023, Listeria ivanovii subsp. ivanovii KCTC 3444, Staphylococcus aureus subsp. aureus KCTC 1916, B. megaterium KCTC 1098 and B. sphaericus KCTC 1184. The bacteriocin was purified through ammonium sulfate concentration, SP-Sepharose chromatography and RP-HPLC. The molecular weight was estimated to be about 3.4 kDa by tricine-SDS-PAGE analysis.