LACTOBACILLUS PLANTARUM ST16Pa - ARE WE READY TO USE IT AS BIO-PROTECTIVE CULTURE

I. Ivanova, M. Wachsman, Ts. Ignatova-Ivanova, Sv. Todorov

Abstract: Lactobacillus plantarum ST16PA was isolated from papaya and previously have been shown that produces a 6.5 kDa bacteriocin, active against different species from genera Enterobacter, Enterococcus, Lactobacillus, Pseudomonas, Streptococcus and Staphylococcus and different serotypes of Listeria spp. In addition Lb. plantarum ST16Pa presented a good potential to be consider as a probiotic candidate based on the genetic and physiological tests. PCR analysis of DNA from Lb. plantarum ST16Pa was generated positive results for presence of nisin and enterocin P genes and no evidences for presence of pediocin PA-1, plantaricin S, plantaricin W, plantaricin NC8, enterocin A, enterocin B or enterocin L50B have been obtained. Based on the molecular size (6.5 kDa as determined by Tricin-SDS-PAGE) of the expressed bacteriocin, most probably Lb. plantarum ST16Pa express bacteriocin different from nisin or enterocin P. Semi-purifi ed bacteriocin was presenting a very high activity against Listeria monocytogenes (102 400 AU ml–1), Peudomonas aeroginosa (25 600 AU ml–1) and Enterococcus faecalis (102 400 AU ml–1). However, when semi-purifi ed bacteriocin have been tested for cytotoxicity, CC50 > 1600 μg ml–1 have been recorded. In addition, Lb. plantarum ST16Pa generated positive PCR results on the DNA level for gelE (gelatinase), hyl (hyaluronidase), asa1 (aggregation substance), ace (adhesion of collagen) and tdc (tyrosine decarboxylase), a high virulence profile when been examined for presence of virulence factors.

Keywords: bacteriocin; cytotoxicity; Lactobacillus plantarum; virulence factors

Date published: 2017-10-20