INVESTIGADORES
SAAVEDRA Maria Lucila
capítulos de libros
Título:
Purification of Bacteriocins Produced by Lactic Acid Bacteria.
Autor/es:
SAAVEDRA LUCILA, CASTELLANO, PATRICIA; SESMA, FERNANDO
Libro:
Public Health Microbiology: Methods and Protocols
Editorial:
Humana Press
Referencias:
Año: 2004; p. 331 - 336
Resumen:
Bacteriocins are antibacterial substances of a proteinaceous nature that are produced
by different bacterial species. Lactic acid bacteria (LAB) produce biologically
active peptides or protein complexes that display a bactericidal mode of action almost
exclusively toward Gram-positive bacteria and particularly toward closely related species.
Generally they are active against food spoilage and foodborne pathogenic microorganisms
including Bacillus cereus, Clostridium perfringens, Staphylococcus aureus,
and Listeria monocytogenes (1,2).Bacillus cereus, Clostridium perfringens, Staphylococcus aureus,
and Listeria monocytogenes (1,2).Listeria monocytogenes (1,2).
There is an increased tendency to use natural occurring metabolites to prevent the
growth of undesirable flora in foodstuffs. These metabolites could replace the use of
chemical additives such as sorbic acid, sulfur dioxide, nitrite, nitrate, and others.
For instance, bacteriocins produced by LAB may be promising for use as biopreservaties
(3,4).,4).,4).
Bacteriocins of lactic acid bacteria are typically cysteine-rich, cationic, hydrophobic
peptides and differ widely in many characteristics including molecular weight,
presence of particular groups of amino acids, pI, net positive charge, and post-translational
modifications of certain amino acids. This heterogeneity within the LAB bacteriocins
may explain the different procedures for isolation and purification developed
so far. The methods most frequently used for isolation, concentration, and purification
involve salt precipitation of bacteriocins from culture supernatants, followed by various
combinations of gel filtration, ion-exchange chromatography, and reverse-phase
high-performance liquid chromatography (RP-HPLC).
In this chapter, a protocol is described that combines several methods used in our
laboratory for the purification of two cationic bacteriocins, Lactocin 705AL and
Enterocin CRL10, produced by Lactobacillus casei CRL705 and Enterococcus mundtiiLactobacillus casei CRL705 and Enterococcus mundtii
CRL10, respectively