Description
Pediocin. Pediocins are class II bacteriocins produced by LAB of the genus Pediococcus and by other gram-positive bacteria (Garvie, 1986). Other class II bacteriocins include carnobacteriocins, sakacins, and leucocins (Holzapfel, Schillinger, Geisen, & Lucke, 2003) . Antimicrobial action is similar to that of nisin (Ray & Miller, 2000) and pediocin is most effective against gram-positive bacteria, although some strains of E. coli may also be sensitive (Osmanagauoglu, Gündüz, Beyatli, & cokmus, 1998) . Others have also observed sensitivity in previously stressed or injured gram-negative bacteria (Kalachayanand, Sikes, Dunne, & Ray, 1998 ; Ray, 1993 ; Ray & Daeshel, 1992) . Pediocins may trigger suicide mechanisms in susceptible cells by inducing the unregulated transcription of lytic enzymes involved in cell lysis (Bhunia et al., 1988 ; Bhunia, Johnson, & Kalchayanand, 1991 ; Ray & Miller, 2000) . Pediocins are tolerant to heat (121°C, 15 min) and high hydrostatic pressure (50,000 psi), and are effective at pH values between 3.0 and 9.0 (Kalachayanand et al., 1998 ; Osmanagauoglu et al., 1998) . The presence of some anions (Cl – , I – , P[O 4 ] 3– ) in high-salt formulations may antagonize pediocin–phospholipid interaction (Bhunia et al., 1991) . Pediocin is a hydrophobic compound, and therefore, less likely to be homogenously distributed in high-fat formulations (Jung et al., 1991 ; Ray & Miller, 2000)
