Isolation and partial characterization of bacteriocins from Pediococcus species

Abstract

Lactic acid bacteria have received increased attention as a potential food preservative due to their strong antagonistic activity against many food-spoilage and pathogenic organisms. Three Pediococcus species, P. acidilactici NCIM 2292 , P. pentosaceous. NCIM 2296 and P. cervisiae NCIM 2171, were evaluated for bacteriocin production. Inhibitory substance were produced during the late growth phase and maximum production occurred at 37 degrees after 36-48 h of incubation. Bacteriocins partially purified from these species by cold-acetone precipitation at 0 degrees C and cell adsorption desorption techniques have a broad inhibitory spectrum against microorganisms, including gram-negative bacteria such as Escherichia coli and Pseudomonas. Proteolytic enzymes inactivated these peptides, but amylase and lipase did not show any effect. The bacteriocins were stable over a wide pH range (3-8) and apparently most active at pH 4.0-5.0. They were heat-stable (1 h at approximately 80 degrees C and autoclaving) at pH 5.0. No loss in activity was observed when stored under refrigeration (4-8 degrees C). Tris-Tricine SDS-PAGE revealed the molecular masses of these peptides to be between 3.5 and 5.0 kDa.

Metagenomics and the niche concept

“…The opposite competitive interaction, termed allelopathy, results in a chemical modification of the habitat by a species that turns the environment inhabitable for another species (Weidenhamer et al 1989). In the bacterial world, allelopathy is exerted by bacteriocin production from some bacterial species (Riley and Gordon 1999), that are effective in inhibiting growth not only for the strains of the some species but also inhibit the growth of different species (Jamuna and Jeevaratnam 2004). Modification of a homogeneous environment by a resident species can also lead to generation of diversity.…”

Preparation and evaluation of sauces from lactic acid fermented vegetables

“…Recently, the presence of bacteriocin-an antimicrobial substance in these products has also attracted the attention of scientists (Luchansky 1999, Jamuna and Jeevaratnam 2004. Products like sauerkraut are produced by mixed natural microfl ora (Joshi and Thakur 2000) while mixed lactic cultures have been employed to study the controlled fermentation of vegetables (Desai and Sheth 1997).…”

Antimicrobial compounds produced by Lactobacillus sakei subsp. sakei 2a, a bacteriocinogenic strain isolated from a Brazilian meat product

“…Many other strategies have been reported in the literature for the purification of antimicrobial peptides and proteins produced and secreted by bacteria [1,3,9,21,34,40,41,44,47]. Generally, the first step is a precipitation with ammonium sulphate [29] or an aqueous extraction of secreted compounds by medium acidification to release cationic compounds bound to the bacteria cell wall [27]. An obvious strategy for the enrichment of those cationic antimicrobial peptides and proteins is a fractionation by ion-exchange chromatography [5,6,11].…”