Abstract:

Rana chensinensis skin was extracted using acidified methanol for preparing anti-bacterial peptides and the resulting crude extract was then purified by gel filtration chromatography. Purified anti-bacterial peptides were found to be rich in F2 fraction up to 90% by tandem Sephadex G-50 and G-25 column chromatography. The purified anti-bacterial peptides could effectively inhibit the growth of Gram-positive bacteria, Gram-negative bacteria and fungus. The minimum inhibitory concentrations (MIC) were 0.2 mg/mL against Staphylococcus aureus and Streptococcus, 0.4 mg/mL against Bacillus subtilis and Escherichia coli, 0.8 mg/mL against Bacillus cereus, 1.2 mg/mL against Candida albicans, 1.5 mg/mL against Saccharomyces cerevisia and Mucor, and 2.0 mg/mL against Rhizopu.

Key words: Rana chensinensis, anti-bacterial peptide, purification, anti-bacterial activity