• Microbiology and Biotechnology Letters
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• v.31 no.3
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• pp.242-249
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• 2003

Antimicrobial activity of Caesalpina sappan L. extract (CS extract) against animal husbandry disease-related bacteria was studied. The CS extracts showed a significant antimicrobial activity against Gram(+) bacteria and this antimicrobial activity was most significant against Staphylococcus epidermidis. Minimum inhibitory concentrations (MIC) of CS was in the range of 0.8∼16 mg/ml and 0.8∼10 mg/ml, in the case of MeOH extracts and EtOH extracts, respectively. In addition, the antimicrobial activity of each solvent fraction was most significant with EtOAc layer. The antimicrobial activities of CS extracts against most microbial strains were stable by either heat treatment or acid treatment, whereas those against S. aureus and Sal. typhimurium were reduced by acid treatment. The inhibitory effect of CS extracts on microbial cell growth was further examined by the addition of 0, 100, 300, and 500 ppm of CS extracts into growth medium. The growth of gram(+) bacteria, S. aureus and S. epidermidis, was inhibited for 72 hours in all ranges of CS extracts added, but the growth of gram(-) bacteria was only inhibited when at least 100 ppm of CS extracts were added. Taken together, the antimicrobial activities of CS extracts were more effective against gram(+) bacteria compared to those against gram(-) bacteria.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.8
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• pp.1214-1220
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• 2003

Antimicrobial activity of Rhus javanica (RJ) extract against animal husbandry disease-related bacteria was determined by a paper disc method. The RJ extracts showed a significant antimicrobial activity against Gram positive (+) bacteria and especially the activity was most potent against L. monocytogenes and S. epidermidis. Minimum inhibitory concentrations (MIC) of the MeOH and EtOH extracts of RJ were in the range of 0.8 ∼ 16 mg/mL and 0.8 ∼ 10 mg/mL, respectively. Furthermore, among five solvent fractions (n-hexane, CHC1$_3$, EtOAc, n-BuOH and $H_2O$ frs.) from MeOH extract of RJ, the EtOAc fr. exhibited the most significant antimicrobial activity The antimicrobial activities of RJ extracts against most microbial strains were unstable by either heat treatment or acid treatment. The inhibitory effect of RJ extracts on microbial cell growth was further examined by the addition of 0, 100, 300, and 500 ppm of RJ extracts into growth medium. The growth of gram positive (+) bacteria, S. aureus, S. epidermidis and L. monocytogenes was inhibited for 72 hours when at least 300 ppm of RJ extracts added, but the growth of gram negative (-) bacteria was only inhibited when at least 500 ppm of RJ extracts were added. Taken together, tile antimicrobial activities of RJ extracts were more effective against gram positive (+) bacteria compared to those against gram negative (-) bacteria.