Detection of bacteriocin activity in bacteria using hydrophobic grid membrane filters

Abstract

Seven known bacteriocin-producing bacterial strains were examined using three newly developed bacteriocin detection methods employing hydrophobic gridmembrane niters (HGMF): (i) filtration, (ii) multiple square inoculation, and (iii) one square inoculation, and the three reference methods: (i) simultaneous direct cross-streak, (ii) deferred direct cross-streak, and (iii) agar disc. The HGMF membrane multiple square inoculation method detected bacteriocin activity in all seven strains. This method also yielded similar or slightly better results than those obtained using the deferred direct cross-streak or agar disc methods. Bacteriocin activity was observed in six of seven and four of seven strains using the one square inoculation and filtration methods, respectively, with corresponding inhibiting zones measuring 2–24 and 6–20 mm in diameter.