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Abstract Background Selection of a microbial strain for the incorporation into food products requires in vitro and in vivo evaluations. A bacteriocin-producing lactic acid bacterium (LAB), Pediococcus acidilactici Kp10, isolated from a traditional dried curd was assessed in vitro for its beneficial properties as a potential probiotic and starter culture. The inhibitory spectra of the bacterial strain against different gram-positive and gram-negative bacteria, its cell surface hydrophobicity and resistance to phenol, its haemolytic, amylolytic and proteolytic activities, ability to produce acid and coagulate milk together with its enzymatic characteristics and adhesion property were all evaluated in vitro. Results P. acidilactici Kp10 was moderately tolerant to phenol and adhere to mammalian epithelial cells (Vero cells and ileal mucosal epithelium). The bacterium also exhibited antimicrobial activity against several gram-positive and gram-negative food-spoilage and food-borne pathogens such as Listeria monocytgenes ATCC 15313, Salmonella enterica ATCC 13311, Shigella sonnei ATCC 9290, Klebsiella oxytoca ATCC 13182, Enterobacter cloaca ATCC 35030 and Streptococcus pyogenes ATCC 12378. The absence of haemolytic activity and proteinase (trypsin) and the presence of a strong peptidase (leucine-arylamidase) and esterase-lipase (C4 and C8) were observed in this LAB strain. P. acidilactici Kp10 also produced acid, coagulated milk and has demonstrated proteolytic and amylolactic activities. Conclusion The properties exhibited by P. acidilactici Kp10 suggested its potential application as probiotic and starter culture in the food industry.

Abstract The microorganisms most commonly used as probiotics are lactic acid bacteria, especially those of the genus Lactobacillus. In the present study, two Lactobacillus strains, L. pentosus ITA23 and L. acidipiscis ITA44, previously isolated from mulberry silage, were characterized for their antiproliferative and antioxidant activities. The antiproliferative effects of the strains were investigated using the MTT assay with breast cancer (MDA-MB-231), liver cancer (HepG2) and normal liver (Chang) cell lines. The strains were tested for their antioxidant activity using the FRAP and ABTS methods. The results showed that the two Lactobacillus strains had good antiproliferative effects against both cancer cell lines tested, while their effects on the normal cells were weak. Based on the results of the antioxidant tests, the intact cells and cell-free extracts of the two Lactobacillus strains showed more than 135 and less than 50 µg trolox/ml of antioxidant activity, respectively. Lactobacillus pentosus ITA23 and L. acidipiscis ITA44 can be considered as potential probiotic candidates for humans because of their antioxidant activity and antiproliferation effects against cancer cells.