Abstract: The present invention relates to anti-contaminant composition comprising a cell-free fermentation product of one or more Bacillus subtilis strains (e.g., selected from the group consisting of: 22C-P1, 15A-P4, 3A-P4, LSSA01, ABP278, BS 2084 and BS 18); wherein said fermentation product comprises one or more compounds selected from the group consisting of: a lipopeptide, a polyketide, a bacillibactin, a bacilysin, an anticapsin, a plantazolicin, a LCI, a homologue of a plantazolicin and a homologue of a LCI. In addition, the present invention further relates to methods of preparing the compositions, methods of using the composition, products comprising the composition and uses thereof.

Abstract: A peptide, produced by propionibacteria, has a molecular weight of between 300 and 1200 daltons and is inhibitory to gram-negative bacteria. The peptide can be produced by purification of a propionibacteria metabolite mixture, by chemical synthesis, or by a host transformed with a recombinant vector, and is useful in preventing and treating bacterial infections.

Abstract: A metabolite material of propionibacteria is added to a food product to inhibit the growth of yeast. The metabolite material is produced by growing propionibacteria cells in a liquid growth medium to produce a mixture containing the metabolite material. The mixture can be concentrated and added to a food product as a concentrated liquid or powder. The metabolite material added to a food product may contain viable cells of propionibacteria.

Abstract: A metabolite material of propionibacteria, having a metabolite of molecular weight greater than 300, is added to a food product to inhibit the growth of gram negative psychotropic bacteria, yeast, mold, gram positive bacteria, or Listeria. The metabolite material may contain less than 0.02% propionic acid such that there is insufficient propionic acid per se to inhibit microbial growth. The metabolite material is produced by growing propionibacteria cells in a liquid growth medium to produce a mixture containing the metabolite material. The mixture can be concentrated and added to a food product as a concentrated liquid or powder. The metabolite material added to a food product may contain viable cells of propionibacteria.