• Biomedical Science Letters
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• v.13 no.1
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• pp.47-53
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• 2007

Due to wide abuse of antibiotics both in human and livestock use, the advent and spread of multidrug resistant (MDR) pathogens becomes a serious health problem all over the world. Since the development of new antibiotics is at a standstill in pharmaceutical industry, the choice of therapeutic antibiotics is getting narrower. In this study, in an effort to search new antibiotics, the antimicrobial activity of Paenibacillus DY1 isolated from Korean soil was characterized on its growth inhibition spectrum against various health threatening MDR strains, with its stability and chemical structure. Extracellular culture filtrate of Paenibacillus DY1 effectively inhibits the growth of all the tested MDR enteropathogenic Eshcherichia coli, enterohemolytic E. coli, and enterotoxigenic E. coli strains, at a similar level to that on the nonresistant control E. coli strains. It showed significant growth inhibition effect against the causative agents of class one legal communicable disease, MDR Salmonella typhi, MDR Salmonella paratyphi A, food poisoning bacteria, MDR Salmonella typhimurium, and other MDR Salmonella spp. The growth of all of 10 different MDR Shigella spp. strains and 6 different Vibrio spp. strains tested was also inhibited. The antimicrobial activity of Paenibacillus DY1 was well preserved after heat treatment, and was also stable in both alkaline and acidic environment. The antimicrobial activity was partially purified with Diaion HP20 column and TLC. By NMR study, the putative structure of the activity was postulated as an alkane having hydroxyl groups.

• Microbiology and Biotechnology Letters
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• v.20 no.5
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• pp.491-497
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• 1992

The water extract of Sinomeniiacuti Radix (Sinomenium acutum) was found out to have a strong inhibition activity on the growth of Clostridium perfringens. The anti-bacterial activity was stable at the range of pH 1 to pH 13 and kept in a thermal treatment at $121^{\circ}C$ for 15 minutes. The minmal inhibition concentration of the Sinomeniiacuti Radix extract on the growth of Cl. peifringens was 1000 ppm. The Sinomeniiacuti Radix extract also suppressed the growth of Cl. ramosum, Cl. paraputnficum, Cl. butyn'cum, Bifidobacterium blficum, Bacteriodes fragilis, Eubacterium limosum. The extract, however, did not inhibit the growth of Bif adolescentis, Blf. infantis, Bif longum, E. coli. Enterococcus faecalis and Staphylococcus aureus. On the other hand, the extract showed a promoting effect for the growth of Bif animalis and Lactobacillus acidophilus.

• Korean Journal of Food Science and Technology
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• v.28 no.4
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• pp.730-735
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• 1996

Antibacterial action of garlic extract against Escherichia coli was investigated. When the survival of E. cloi in tryptic soy broth (TSB) containing 50% garlic extract was compared with those of Lactobacillus plantarum, Leuconostoc mesenteroides and Staphylococcus aureus, E. coli was the most sensitive to garlic antibacterial action. When E. coli was inoculated into TSB with different concentrations of garlic extract, viable cell number decreased continuously during the test period even at 1% garlic extract. When E. coli was inoculated into pH-adjusted TSB containing 0.5% garlic extract, viable cell number of E. coli decreased continuously at initial pH of 5.2 and 6.2, while it decreased initially but increased to $8.0{\times}10^{7}\;CFU/ml at 48 hr at pH 7.2. With larger initial populations $(10^{6}\;CFU/ml), E. coli grew without apparent inhibition, while with smaller initial populations $(<10^{5}\;CFU/ml), viable cell number decreased initially but later increased. Thiol compounds like cysteine and glutathione, with free SH group (s), helped E. coli to grow or survive better in TSB with inhibitory level (5%) of garlic extract. The possibility of eliminating E. coli by using garlic extract from foods like kimchi of which garlic is one of regular ingredients is suggested.