• Title/Summary/Keyword: biotechnology and medical engineering

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Antimicrobial Effect of Medical Adhesive Composed of Aldehyded Dextran and ${\varepsilon}$-Poly(L-Lysine)

  • Lee, Jeong-Hyun;Kim, Hye-Lee;Lee, Mi-Hee;Taguchi, Hideaki;Hyon, Suong-Hyu;Park, Jong-Chul
    • Journal of Microbiology and Biotechnology
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    • v.21 no.11
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    • pp.1199-1202
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    • 2011
  • Infection of surgical wounds is a severe problem. Conventional tissue reattachment methods have limits of incomplete sealing and high susceptibility to infection. Medical adhesives have several advantages over traditional tissue reattachment techniques, but still have drawbacks, such as the probability of infection, low adhesive strength, and high cytotoxicity. Recently, a new medical adhesive (new-adhesive) with high adhesive strength and low cytotoxicity, composed of aldehyded dextran and ${\varepsilon}$-poly(L-lysine), was developed. The antimicrobial activity of the new-adhesive was assayed using agar media and porcine skin. In the agar diffusion method, inoculated microorganisms that contacted the new-adhesive were inactivated, but this was not dependent on the amount of new-adhesive. Similar to the agar media results, the topical antimicrobial effect of new-adhesive was confirmed using a porcine skin antimicrobial assay, and the effect was not due to physical blocking based on comparison with the group whose wounds were wrapped.

Ginsenoside Rb1 is Transformed into Rd and Rh2 by Microbacterium trichothecenolyticum

  • Kim, Hansoo;Kim, Jeong-Hoon;Lee, Phil Young;Bae, Kwang-Hee;Cho, Sayeon;Park, Byoung Chul;Shin, Heungsop;Park, Sung Goo
    • Journal of Microbiology and Biotechnology
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    • v.23 no.12
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    • pp.1802-1805
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    • 2013
  • Ginsenosides are the most important ingredient of ginseng and are known to possess many pharmacological and biological effects. Rb1, a major protopanaxadiol ginsenoside, is the most abundant ginsenoside in Panax ginseng C.A Meyer and can be hydrolyzed into more pharmaceutically potent minor ginsenosides. To identify a microorganism that is capable of converting Rb1 into other ginsenosides, we screened 12 Microbacterium spp., and M. trichothecenolyticum was identified as a likely candidate. M. trichothecenolyticum converted Rb1 into Rd and then into Rh2 based on TLC and HPLC analyses of reaction products. This biotransformation method can be easily applied for mass production of Rd and Rh2 by using Rb1.

Inactivation of Listeria monocytogenes in Brine and Saline by Alternating High-Voltage Pulsed Current

  • Lee, Mi-Hee;Han, Dong-Wook;Woo, Yeon-I.;Uzawa, Masakazu;Park, Jong-Chul
    • Journal of Microbiology and Biotechnology
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    • v.18 no.7
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    • pp.1274-1277
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    • 2008
  • The inactivating efficiency of alternating high-voltage pulsed (AHVP) current was investigated in brine (20 w/v% NaCl) and saline (0.9 w/v% NaCl) inoculated with $1\times10^7$ cells/ml of Listeria monocytogenes. AHVP current at 12 V with 1 pulse completely inactivated L. monocytogenes in brine within 3 ms, while the bacteria in saline were fully inactivated by 10-pulsed electric treatment at 12 V within the same time. Electron microscopic observation demonstrated substantial structural damage of electrically treated L. monocytogenes in brine. These results suggest that AHVP treatment would be effective for the rapid and complete inactivation of L. monocytogenes in brine or saline solution.

Discovery of Novel and Potent Cdc25 Phosphatase Inhibitors Based on the Structure-Based De Novo Design

  • Park, Hwang-Seo;Jung, Suk-Kyeong;Bahn, Young-Jae;Jeong, Dae-Gwin;Ryu, Seong-Eon;Kim, Seung-Jun
    • Bulletin of the Korean Chemical Society
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    • v.30 no.6
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    • pp.1313-1316
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    • 2009
  • Cdc25 phosphatases have been considered as attractive drug targets for anticancer therapy due to the correlation of their overexpression with a wide variety of cancers. We have been able to identify five novel Cdc25 phosphatase inhibitors with micromolar activity by means of a structure-based de novo design method with a known inhibitor scaffold. Because the newly discovered inhibitors are structurally diverse and have desirable physicochemical properties as a drug candidate, they deserve further investigation as anticancer drugs. The differences in binding modes of the identified inhibitors in the active sites of Cdc25A and B are addressed in detail.

Purification and Characterization of Neoagarotetraose from Hydrolyzed Agar

  • Jang, Min-Kyung;Lee, Dong-Guen;Kim, Nam-Young;Yu, Ki-Hwan;Jang, Hye-Ji;Lee, Seung-Woo;Jang, Hyo-Jung;Lee, Ye-Ji;Lee, Sang-Hyeon
    • Journal of Microbiology and Biotechnology
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    • v.19 no.10
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    • pp.1197-1200
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    • 2009
  • The whitening effect, tyrosinase inhibition, and cytotoxicity of neoagarotetraose were measured after its purification from hydrolyzed agar by gel filtration chromatography. In melanoma B16F10 cells, the melanin content of neoagarotetraose-treated cells was the same as that treated by kojic acid or arbutin. In addition, tyrosinase of melanoma cells was strongly inhibited by neoagarotetraose at a concentration of $1{\mu}g/ml$ and similarly inhibited at 10 and $100{\mu}g/ml$ compared with those by arbutin or kojic acid. The activity of mushroom tyrosinase showed a 38% inhibition by neoagarotetraose at $1{\mu}g/ml$, and this inhibitory effect was more efficient than that by kojic acid. Neoagarotetraose revealed a similar $IC_{50}$ (50% inhibition concentration) value for mushroom tyrosinase as that by kojic acid. These data suggest that the neoagarotetraose generated from agar by recombinant $\beta$-agarase might be a good candidate as a cosmetic additive for the whitening effect.

Detection of Oleic Acid Biodegradation by Fungi

  • Han, Dong-Wook;Suh, Hwal;Lee, Dong-Hee;Park, Bong-Joo;Kosuke Takatori;Park, Jong-Chul
    • Journal of Microbiology and Biotechnology
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    • v.12 no.3
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    • pp.514-517
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    • 2002
  • To investigate oleic acid biodegradation, 47 fungal strains were tested with modified Czapek Dox broth media containing oleic acid, and their biodegradative activities were assayed by measuring the release of $[^14C]CO_2$ from the $^14C-$labeled oleic acid. After 72 h of cultivation, Aspergillus flavus, Aspergillus ochraceus, and Alternaria species metabolized approximately $25\%\;to\;35\%$ of the supplied oleic acid. The relationship between the fungal degradation of oleic acid and the fungal growth was also examined using 7 strains of Aspergillus niger. A. niger. YMC 0100 and YMC 0322 degraded about $26\%$ of the oleic acid after 72 h, while their germination ratios were more than $30\%$.