Bacteriocin produced by Pediococcus sp in kimchi and its characteristics

Abstract

A bacteriocin-producing strain identified as Pediococcus acidilactici was isolated from kimchi. The bacteriocin was identified to belong to the pediocin family and exhibited bactericidal activity against most Gram-positive bacteria as well as some Gram-negative bacteria. The bacteriocin was stable up to 80degreesC with wide pH ranges (5.0-10.0). The bactericidal activity remained unchanged after treatment with nonproteolytic enzymes such as nuclease and alpha-amylase, however, it was destroyed after treatment with protease. The bacteriocin was effectively extracted by the pH-mediated adsorption-desorption method and purified effectively by semi-preparative RP-HPLC. The molecular weight of the bacteriocin was 4,622, as determined by electrospray mass spectrometry. The amino acid sequence consisted of 44 amino acid residues with four cysteines. The high solubility and pH stability of the isolated pediocin provide definite advantages over nisin and other bacteriocins in regards to its potential applications.