Inhibition of Psychrotrophic Organisms by Propionicin PLG-1, a Bacteriocin Produced by Propionibacterium thoenii

Abstract

Propionibacterium thoenii strain P127, which produces the bacteriocin propionicin PLG-1, was grown in a skim milk medium and produced bacteriocin in that medium. No bacteriocin activity was detected in skim milk medium in which strain P127-1, a bacteriocin-negative variant of strain P127, had been grown. Five psychrotrophic spoilage or pathogenic organisms (one strain each of Listeria monocytogenes, Pseudomonas fluorescens, Vibrio parahaemolyticus, Yersinia enterocolitica, and one strain of Corynebacterium sp.) were incubated for 24 h in laboratory medium, nonfermented skim milk, and skim milk that had been fermented by strain P127 or P127-1. Strains were inhibited only in the skim milk fermented by strain P127, as evidenced by loss in numbers of viable cells after 24 h at 10 degrees C and less growth than in other media after 24 h at optimal growth temperatures. Growth of selected strains was delayed or slowed during prolonged incubation (21 d) at 10 degrees C. Propionicin PLG-1 shows promise as a preservative for food products.

Dairy Propionibacteria: Less Conventional Probiotics to Improve the Human and Animal Health

“…Among them it could be mentioned: Propionicin PLG-1 and GBZ-1 produced by P. thoenii 127 [81]; Jenseniin G isolated from P. thoenii P126 [82]; Propionicins SM1 and SM2 produced by P. jensenii DF1 [83]; Propionicin T1 synthesized by P. thoenii 419 and LMG2792 [84]; Thoenicin 447 isolated from P. thoenii 447 [85]; Acnecin produced by a strain of P. acnes [86] and several other propionicins [87][88][89].…”

Partial purification and characterization of the bacteriocin produced by Propionibacterium jensenii B1264

“…It is sensitive to protease, pronase E, pepsin, trypsin, and oe-chymotrypsin, insensitive to catalase, and lipase but stable from pH 3 to 9 and to temperatures~85 -c. The bacteriocin is produced in late stationary phase in agar and broth cultures [12]. Its production has been examined in both batch [9,12] and fed-batch [16] fermentations; five times more activity is produced in cultures grown at pH 7.0 in a 3: 1 beet molasses:com steep liquor medium than in sodium lactate broth. Propionicin PLG-I is bactericidal to P. acidipropionici P5 without causing cell Iysis; it kills 99.6 % of indicator cells within 60 min [12].…”

“…Its production has been examined in both batch [9,12] and fed-batch [16] fermentations; five times more activity is produced in cultures grown at pH 7.0 in a 3: 1 beet molasses:com steep liquor medium than in sodium lactate broth. Propionicin PLG-I is bactericidal to P. acidipropionici P5 without causing cell Iysis; it kills 99.6 % of indicator cells within 60 min [12]. Lyon and G1atz [12] purified propionicin PLG-I to homogeneity by sequential ammonium sulphate precipitations first at 40 % and then at 60 %, ion exchange chromatography on carboxymethyl cellulose and preparative isoelectric focussing.…”

“…Propionicin PLG-I is produced by P. thoenii P127 [II,12] and inhibits Gram-positive bacteria including P. thoenii, P. acidipropionici, P. jensenii and lactic acid bacteria, Gram-negative bacteria (Pseudomonas, Vibrio, and Campylobacter spp. and Escherichia coli), and selected yeasts and molds [II].…”

“…Dairy or classical propionibacteria include Propionibacterium freudenreichii, P. thoenii, P. acidipropionici and P. jensenii, and have been isolated from cheese, milk products, soil, olives and sil age fermentations [3].Their industrial importance lies in their production of Swiss cheese flavor and 'eyes', vitamin B 12 and inhibitors, includ-.. ing propionic acid and bacteriocins (antimi-. crobial proteins).…”