Characterization of bacteriocins produced by Lactococcus lactis strains

Abstract

Bacteriocins produced by fifteen strains of Lactococcus lactis (14 L. lactis subsp. lactis and one L. lactis subsp. cremoris) were heat resistant, sensitive to several proteolytic enzymes and active over a wide range of pH. Their resistance to the heating was greatly influenced by the pH. Only the strain L. lactis subsp. lactis ITAL 383 produced a bacteriocin with a wide activity spectrum, similar to nisin of L. lactis subsp. lactis ATCC 11454. This bacteriocin inhibited closely related species and other Gram-positive microorganisms including Listeria monocytogenes and Staphylococcus aureus, but it was not active against the Gram-negative bacteria tested. The identification of partially purified antimicrobial compounds by SDS-PAGE showed that bacteriocin produced by strain ITAL 383 had the same molecular weight of nisin produced by L. lactis subsp. lactis ATCC 11454.

Evaluation of the heteroantagonism between Enterobacter agglomerans strains isolated from vulture (Coragyps atratus) for production and Pseudomonas aeruginosa as developed

“…Da mesma forma, Moreno et al (2000), com o intuito de testar a produção de bacteriocinas por Lactococcus, verificaram que o método de antagonismo simultâneo por inoculação em poços permitiu a formação de halos de inibição maiores e mais consistentes. Esse método mostrou ser mais sensível aos métodos de inoculação em forma de pontos e de estrias, pela possibilidade de comparação da concentração de bacteriocinas produzidas pelas diferentes linhagens examinadas.…”

Bacteriocins from lactic acid bacteria: purification, properties and use as biopreservatives

“…One example of this second type is nisin, which is produced by certain strains of Lactococcus lactis subsp. lactis (De Vuyst, 1994;Rodriguez, 1996;Moreno et al, 2000). Other is pediocin, produced by Pedicoccus pentosaceus (Moreno et al, 2006).…”

“…Bacteria from this group are involved in the production of the lantibiotic nisin, lactococcins, lactostrepcins, diplococcins and others (Mackay et al, 1997;Moreno et al, 2000). Cheigh et al (2004) have developed a simple onestep purification method, using expanded bed ionexchange chromatography, for the fractionation of nisin Z produced by Lactococcus lactis subsp.…”

Isolation of bacteriocin-producing lactic acid bacteria from meat and meat products and its spectrum of inhibitory activity

“…Some authors differentiate nisin from other lactococcal bacteriocin by the fact that α-chymotrypsin is the only proteolytic enzyme to which nisin is sensitive (14,22). Nevertheless, this property is to be regarded with caution, since other authors have reported that nisin can also be inactivated by other enzymes such as pronase E (15,23), and ficin (5,21).…”