• Microbiology and Biotechnology Letters
• /
• v.32 no.1
• /
• pp.52-59
• /
• 2004

When both fructose and galactose were added to a production medium as carbon sources, the productivity of PAFS (Psedomonas Antifungal Substance) biosynthesized by Pseudomonas aeruginosa was observed to be reduced significantly due to the well-known phenomenon of catabolite repression. In order to overcome this phenomenon by use of fermentation bioprocess, fed-batch cultivation method was examined. In addition, a high producer mutant strain, AP-20 obtained by a rational screening method was tested for its productivity of PAFS in both batch and fed-batch fermentation processes. Notably fed-batch operation showed approximately 4 fold higher PAFS productivity than traditional batch operation process. It was appeared that galactose was utilized principally for the cell growth of Pseudomonas aeruginosa whereas large portion of fructose was used for the biosynthesis of PAFS. Furthermore it was observed that composition and feeding rate of production media should be optimized even in the fed-batch fermentation bioprocess. As an example, very slow feeding of carbon sources gave rather negative effect on the production of PAFS due to significant limitation of carbon and energy sources available for the producer microorganism.

• Journal of Life Science
• /
• v.12 no.6
• /
• pp.803-811
• /
• 2002

The present study was carried out for research and development of natural antimicrobial from extract of Stachys sieboldii MIQ against food borne bacteria. The hexane extract of Stachys sieboldii MIQ at 250$\mu\textrm{g}$/$m\ell$ per disc showed 15 ~ 20 mm inhibition zone against gram positive and gram negative barteria. Minimum inhibitory concentration (MIC) of hexane extract was 250${\mu}g$/$m\ell$against Bacillus cereus, 250~500${\mu}g$/$m\ell$against Listeria monocytogenes, 500${\mu}g$/$m\ell$ against Staphylococcus aureus, Psedomonas aeruginosa. Observation by transmission electron microscope, showed that disruption of the cell wall assumed to be due to the bactericidal activity. In addition, the membrane integrity of the sensitive cells was disrupted by exposure to Stachys sieboldii MIQ extract on the D-$\beta$-galatosidase activity as substrate of O-nitrophenol-$\beta$-D-galacto-pyranoside. The hexane extract of Stachys sieboldii MIQ was very stable on the pH and thermal stability.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.32 no.6
• /
• pp.825-828
• /
• 2003

This study was performed to determine the antimicrobial activity of waste food fractions, the Solanum tuberosum Peel (SP) and Allium cepa L. Peel (AP) on several microorganisms. The methanol extracts (SPM, APM) of SP and AP were fractionated to five different types, which were hexane, ethylether, ethylacetate, butanol and water Among the various fractions, ethylether and butanol fractions of AP (APMEE, APMB) showed stronger antimicrobial activity against Pseudomonas aeruginosa and Staphylococcus aureus than the other fractions. The ethylether fraction of SP (SPMEE) also showed the higher antimicrobial activity against Escherchia coli than the other 4 fractions . These results suggest that the waste food fractions, SP and AP may be developed into bioactive antimicrobial health products.

• Journal of the Korean Society of Food Culture
• /
• v.19 no.2
• /
• pp.170-176
• /
• 2004

The antioxidative and antimicrobial activity were carried on the Chopi(Zanthoxylum pipperitum) extracts by six kinds of solvents in order to find out new natural food additives. Six solvents were used methanol(MeOH), n-hexan(hexane), chloroform$(CHCl_3)$, ethylacetate(EtOAc), buthanol(BuOH), and water(water) and methanol extract(MEex), hexan extract(HEex), chloroform extract(CHex), ethylacetate extract(EAex), and buthanol extract(BUex), water extract(WAex). The antioxdative activities of them extracts were determined by peroxide value(POV), conjugated diene value(CDV) of corn germ oil storaged for 30 days at $60{\pm}2^{\circ}C$. These extracts were added as 0.02, 0.1, 0.2% of each extracts and compared with ${\alpha}-tocopherol$, and BHT. The antioxidative activities of 0.02% extract were as follows in decreasing order BUex > WAex, BHT, MEex > HEex, EAex, CHex > TOC, and control. While, BUex and CHex among these extracts were shown to be had antimicrobial effects on the microorganism such as Escheria coli, Salmonella typhimurium, Psedomonas aeruginosa, Staphylococcus aureus, and Listeria monocytogenes. Finally to find out the preference of chopi we had made Yugwanzageon (a kind of shallow fried meat ball)by adding chopi powder. The result were similar to control(not added chopi powder) in case of 0.1% chopi adding Yugwanzageon.(p<0.05) Therefore it was thought to be possible that chopi powder was used Yugwanzageon preperation.