Bacteriocin production of probiotic Lactobacillus gasseri LA39 isolated from human feces in milk-based media

The use of bacteriocins from Lactobacillus gasseri, a probiotic lactic acid bacterium, as bio-preservatives in the food industry and animal formulations has been limited because few strains of Lb. gasseri are cultivated and produce a bacteriocin in natural media such as milk and milk-based media. By the determination of the growth-supplements to milk among the 47 nutrients, Lb. gasseri JCM1131^T, LA39 and LA158 isolated from human feces were successfully cultured in reconstituted skim milk and cheese whey using proteose peptone as a nutrient supplement, where Lb. gasseri LA39 produced a useful bacteriocin, gassericin A, with effective growth-inhibiting activity against Gram-positive food-borne pathogens. The data suggest these developed low-cost safe media supporting enough production of bacteriocins by the probiotic Lb. gasseri LA39 could be used to improve the safe bio-preservation of foods and therapy of bovine mastitis, and extra cheese whey produced by cheese making industry is reused in the cultivation for probiotics effectively.