• Journal of Environmental Health Sciences
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• v.23 no.2
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• pp.12-23
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• 1997

The biosynthesis of galactolipid, galactose and the fatty acid composition in E. cdi and B. subtills treated with potassium dichromate(PD, 500 ppm, 500 ppm), potassium chromate(PC, 500 ppm, 500 ppm), cobalt chloride(CC, 100 ppm, 10 ppm) and methylmercuric chloride(MC, 100 ppm, 10 ppm) during the culture were analyzed to compare with the control. The growth rate of cells, the contents of monogalactosyldiglyceride(MGDG), digalactosyldiglyceride(DGDG) and total lipid in the metal compound treatments were lower as compared with the control. And too, the contents of galactose utilized for the biosynthesis of galactolipids in these strains in the various metal compounds treatments were inhibited. The fatty acids used for the MGDG and DGDG formation in E. coli and B. subtills treated with each metal compounds during the culture were showed to the variant compositional change.

• Korean Journal of Microbiology
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• v.17 no.1
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• pp.16-24
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• 1979

In order to investigate the production of aflatoxin in various conditions such as pH, moisture and temperature, 27 smaples were inoculated with Aspergillus flavus, and in addition 3 smaples were inoculated with the mixture of Aspergillus flavus and Bacillus subtilis and cultured under the conditions such as $20^{\circ}C$ and 30% moisture contents. The following results were obtained : 1) Aflatoxin production was the highest at pH 5.0 and relatively high at pH 7.0. Its production was decreased significantly when pH reached 9.0. 2) The yield of aflatoxin was shown comparatively high level at 30% moisture contens. The higher moisture contents was, the lower aflatoxin production was. 3) The highest level of aflatoxin production was at $20^{\circ}C$, and comparatively high level was at $30^{\circ}C$. However, its production was fairly low at $40^{\circ}C$. 4) The highest crude aflatoxin production was 5,093ppm $(B_1,\;1.912\;ppm;\;B_2,\;0.521\;ppm;\;G_1,\;2.119\;ppm;\;G_2,\;0.541\;ppm)$ at 30% moisture, pH 5.0 and $20^{\circ}C$ and the lowest one 2.197 ppm $(B_1,\;0.793\;ppm;\;B_2,\;0.185\;ppm;\;G_1,\;0.102\;ppm;\;G_2,\;0.381\;ppm)$ at 63% moisture, pH 9.0 and $40^{\circ}C$ 5) When Aspergillus flavus and Bacillus subilis were cultured together under the conditions such as $20^{\circ}C$ and 30% moisture, aflatoxin production was decreased by 27% comparing with the culture of Aspergillus flavus alone.

• Microbiology and Biotechnology Letters
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• v.42 no.4
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• pp.393-401
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• 2014

A bacterium producing antimicrobial substance was isolated from cheonggukjang. The bacterium was identified as a strain of Bacillus subtilis by 16S rDNA sequencing and designated as Bacillus subtilis HH28. The antimicrobial substance produced from Bacillus subtilis HH28 was purified by 0-80% ammonium sulfate precipitation, DEAE-sepharose FF column chromatography, and Sephacryl S-200 HR gel chromatography. The molecular weight of the purified antimicrobial substance was estimated to be approximately 3,500 Da using Tricine sodium dodecyl sulfate-polyacrylamide gel electrophoresis and direct detection analysis. Antimicrobial substance from B. subtilis HH28 not only inhibited B. cereus, but also Listeria monocytogenes and Vibrio parahaemolyticus. The purified antimicrobial substance was stable at $40-80^{\circ}C$, and between pH 2 and 8. Antimicrobial activity of the purified substance was completely destroyed by treatment of protease, proteinase K, and pronase E, indicating that it is proteinaceous.

• Korean Journal of Microbiology
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• v.9 no.3
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• pp.130-138
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• 1971

In order to investigate the production of aflatoxin in various conditions such as pH, moisture and temperature, 27 smaples were inoculated with Aspergillus flavus, and in addition 3 smaples were inoculated with the mixture of Aspergillus flavus and Bacillus subtilis and cultured under the conditions such as 20.deg.C and 30% moisture contents. The following results were obtained : 1) Aflatoxin production was the highest at pH 5.0 and relatively high at pH 7.0. Its production was decreased significantly when pH reached 9.0. 2) The yield of aflatoxin was shown comparatively high level at 30% moisture contens. The higher moisture contents was, the lower aflatoxin production was. 3) The highest level of aflatoxin production was at 20.deg,C, and comparatively high level was at 30.deg.C. However, its production was fairly low at 40.deg.C. 4) The highest crude aflatoxin production was 5,093ppm (B$_{1}$, 1.912ppm ; B$_{2}$, and the lowest one 2.197 ppm (B$_{1}$, 0.793 ppm : B$_{2}$, 0.185 ppm : G$_{1}$ ,0.102 ppm G$_{2}$, 0.381ppm) at 63% moisture, pH 9.0 and 40.deg.C. 5) When Aspergillus flavus and Bacillus subilis were cultured together under the conditions such as 20.deg.C and 30% moisture, aflatoxin production was decreased by 27% comparing with the culture of Aspergillus flavus alone.