Naslov
S-layer proteins and bacteriocins of probiotic Lactobacillus strains

Autori
Uroić, Ksenija ; Banić Martina ; Durgo, Ksenija ; Novak, Jasna ; Leboš Pavunc, Andreja ; Kos, Blaženka ; Šušković, Jagoda

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, ostalo

Skup
6th Croatian Congress of Microbiology with International Participation

Mjesto i datum
Sveti Martin na Muri, Hrvatska, 15.06.2016. - 18.06.2016

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Nije recenziran

Ključne riječi
S-layer proteins ; bacteriocins ; GIT

Sažetak
Autochthonous S-layer-expressing strain Lactobacillus brevis ZG1, isolated from traditionally produced fresh cheese, was investigated to be defined as a potentially probiotic strain. This strain displayed high autoaggregation ability, which was negatively affected by the removal of S-layer proteins from the cell surface using 5M guanidine hydrochloride (GHCl). Furthermore, the capacity of L. brevis ZG1 to adhere to extracellular matrix proteins fibronectin and collagen, to mucin and to Caco-2 intestinal epithelial cell line in vitro was assayed, where the removal of the S-layer proteins decreased its adhesion properties. Presence of S-layer proteins on the cell surface ensured better survival of L. brevis ZG1 in simulated conditions of the gastrointestinal tract (GIT), as well as survival during the process of freeze-drying, which are important prerequisites for exertion of probiotic activity. Another feature specific to certain strains of lactic acid bacteria, which gives them selective advantage when applied as probiotic or functional starter cultures, is antimicrobial activity. It was revealed that strain L. brevis ZG1 inhibits growth of six potentially pathogenic microorganisms. Besides antimicrobial activity, coaggregation of probiotic strains with pathogens enables them to form a barrier that prevents colonization of pathogenic bacteria. Coaggregation of strain L. brevis ZG1 with pathogens was shown to be successful after 4 hours of co-incubation. Furthermore, competitive exclusion of pathogenic bacteria Salmonella enterica serovar Typhimurium FP1 and Escherichia coli 3014 was assayed in vitro using Caco-2 cell line. It was discovered that the presence of L. brevis ZG1 cells decreases adhesion of pathogenic cells. Screening for genes encoding various bacteriocins was performed using PCR method with specific primers. It was found that L. brevis ZG1 carries genes plnA, plnEF, plnJ and plnS. All the obtained results indicate that S-layer proteins and bacteriocins enhance probiotic activity of Lactobacillus brevis ZG1.

Izvorni jezik
Engleski

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