PURIFICATION OF BIOACTIVE COMPOUNDS PRODUCED BY BREVIBACILLUS LATEROSPORUS SA14 AND ITS ANTI-MRSA ACTIVITY

Abstract

An antimicrobial peptides (AMPs)- producing strain, Brevibacillus laterosporus SA14,
has been isolated from air. The corresponding AMPs were purified from 4-day culture
supernatant to homogeneity by 50% saturated ammonium sulfate precipitation,
sequential SP-Sepharose Fast Flow and C18 reverse-phase high performance liquid
chromatography. The final purification step, three active fractions were harvested at
retention time about 22.90, 23.20 and 26.30 min, designated as SA14-A, SA14-B and
SA14-C, respectively. The three AMPs showed antibacterial activity against fifty clinical
isolates of methicillin-resistant Staphylococcus aureus (MRSA) which had the specific
activity of about 300 AU/ml. In this study, the bioactive compounds that produced by B.
laterosporus SA14 contained AMPs which are medically important substances may be
used for alternative treatment of MRSA infection if it has been additionally studied to
cytotoxicity against normal human cell.