Lactococcin MMFII, a novel class IIa bacteriocin produced by Lactococcus lactis MMFII, isolated from a Tunisian dairy product

Abstract

A novel bacteriocin, lactococcin MMFII, produced by Lactococcus lactis MMFII isolated from a Tunisian dairy product had been identified. The bacteriocin was purified to homogeneity from fresh overnight M17 broth culture by sulfate ammonium precipitation, cationexchange chromatography, sep-pack chromatography and two steps of reverse-phase chromatography. The purified bacteriocin was heat stable, pH resistant and protease sensitive. Its amino acid sequence, obtained by Edman degradation, revealed a 37-amino acid peptide with two cysteine residues in positions 9 and 14 and a calculated mass of 4144.6 Da. Laser desorption mass spectrometry analysis gave a molecular mass of 4142.6, suggesting the presence of a disulfide bond within the purified bacteriocin. Lactococcin MMFII contains the Nterminal YGNGV consensus motif and is active against Listeria. Thus, it belongs to the class IIa bacteriocins figuring the first example of such a bacteriocin produced by a lactococcal strain. ß

Characterization of bacteriocins produced by lactic acid bacteria isolated from spoiled black olives

“…Lactocin NK24 lost 87.5% of its activity after treatment for 30 min at 100 °C and was completely inactivated after 15 min at 121 o C (LEE and PAIK 2001). In the case of lactocin MMFII, only 8.3% of activity was recorded after 30 min at 110 °C or 25% after 30 min at 80 °C and 100 °C, respectively (FERCHICHI et al 2001). Nisin, produced by L. lactis WNC20, was inactivated after 15 min at 121 °C at pH 7.0, but remained stable at this temperature when suspended at pH 3.0 (NOONPAKDEE et al 2003).…”

Characterization of bacteriocin HV219, produced by Lactococcus lactis subsp. lactis HV219 isolated from human vaginal secretions

“…Lactocin NK24, produced by L. lactis, lost 87.5% of its activity after 30 min at 100 °C and was completely inactivated after 15 min at 121 °C (LEE and PAIK 2001). In the case of lactocin MMFII produced by L. lactis, only 8.3% of activity was recorded after 30 min at 110 °C or 25% after 30 min at 80 °C and 100 °C, respectively (FERCHICHI et al 2001). Nisin, produced by L. lactis WNC20, was inactivated after 15 min at 121 °C when incubated at pH 7.0, but not when incubated at pH 3.0 at this temperature (NOONPAKDEE et al 2003).…”

“…lactis is probably the best studied and belongs to the class II bacteriocins (BERTRAND et al 2001, MATSUSAKI et al 1996, NOONPAKDEE et al 2003. Bacteriocin 481, produced by L. lactis CNRZ 481 (PIARD et al 1992); a nisin-like bacteriocin, produced by L. lactis A164 (CHEIGH et al 2002); lactococcin MMFII, produced by L. lactis MMFII (FERCHICHI et al 2001); a bacteriocin produced by L. lactis KSA2386 (KO andAHN 2000) and lacticin NK24, produced by L. lactis NK24 (LEE and PAIK 2001) are less well studied. Little is known about the influence of medium composition on the production of bacteriocins produced by Lactococcus spp., except for the studies conducted on nisin (DE VUYST 1995, DE VUYST andVANDAMME 1993), lacticin 481 (PIARD 1994) and bacteriocin ST34BR .…”

Characterization and Structure Analysis of a Novel Bacteriocin, Lacticin Z, Produced byLactococcus lactisQU 14

“…10) Since nisin was first identified in 1928, a large number of L. lactis species have been found to produce bacteriocins. According to Klaenhammer' 11) assigned to class IIa. Among these lactococcal bacteriocins, class I bacteriocins, such as nisin, lacticin 481, and lacticin 3147, have been well characterized and actively investigated for future applications.…”