A total of 2257 lactic acid bacteria were preliminarily screened for antagonistic activity against subsp. JCM 1157. Strain SKI19 was selected and identified at the subspecies level as subsp. SKI19, using rRNA gene sequence analysis combined with and genes' amplification. Antibacterial activity of SKI19 was completely lost after treatment of neutralized cell free culture supernatant with proteolytic enzymes, suggesting that SKI19 produced a bacteriocin-like substance that inhibited not only closely related species, but was also effective against DMST 17303. Viewed under scanning electron microscope, cell membranes of the indicator strain appeared to collapse after exposure to the bacteriocin-like substance. In vitro tests concerning probiotic properties, SKI19 survived under simulated gastrointestinal tract conditions, and adhesion of its cell surface to xylene and chloroform was 90.14 and 89.85%, respectively. Complete inhibition by SKI19 against pathogenic bacteria ( DMST 4212, DMST 17303, and DMST 8840) was observed in co-cultivation under anaerobic conditions. A safety assessment showed that SKI19 was susceptible to several antibiotics and had no haemolytic activity. PCR amplification of virulence factors with the specific primers for ,, , , , and genes were negative for SKI19. Also, SKI19 did not harbor any ,, or genes involved in biogenic amine production. The results reveal that SKI19 has probiotic potential and antibacterial activity, and is safe for further application in certain food products.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.