Uloga S-proteina u probiotičkom djelovanju soja Lactobacillus brevis ZG1

master's thesis

• Title (english): The role of S-layer proteins in probiotic mechanism of action in strain Lactobacillus brevis ZG1
• Author: Katarina Zorić
• Mentor: Blaženka Kos (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Biochemical Engineering); (Laboratory for Antibiotic, Enzyme, Probiotic and Starter Cultures Technology); Zagreb
• Defense date and country: 2016-07-08, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Veliku ulogu u probiotičkom djelovanju bakterija mliječne kiseline iz roda Lactobacillus imaju površinski S-proteini koji zbog izravnog kontakta s okolišem sudjeluju u bakterijskoj adheziji na različite supstrate i površine te imaju zaštitnu ulogu u nepovoljnim uvjetima. Cilj ovog rada bio je ispitati ulogu S-proteina u probiotičkom djelovanju soja Lactobacillus brevis ZG1, pri čemu je kao pozitivna kontrola korišten soj Lactobacillus helveticus M92 koji sadrži S-proteine, a kao negativna soj Lactobacillus plantarum D13 koji ne sadrži S-proteine. Dokazano je da soj L. brevis ZG1 sadrži S-proteine kao i proteine koji su vezani na njih (eng. Surface-Layer Associated Proteins, SLAP) čija je funkcija još uvijek nepoznata. Dokazano je da S-proteini sojeva L. helveticus M92 i L. brevis ZG1 imaju zaštitnu ulogu u nepovoljnim uvjetima gastrointestinalnog trakta. Nadalje, ustanovljeno je da sojevi L. helveticus M92 i L. brevis ZG1 pokazuju, dok soj L. plantarum D13 ne pokazuje proteolitičku aktivnost u obranom mlijeku. Ispitivanjem adhezije na mucin ustanovljena je znatno slabija adhezija nakon uklanjanja S-proteina i SLAP proteina s površine ispitivanih bakterijskih stanica.

Abstract (english)

S-layer proteins have a huge role in probiotic mechanism of action in Lactobacillus genus of lactic acid bacteria. This proteins, which have direct contact with the environment of the cells, are involved in bacterial adhesion to different substrates and surfaces and also have a protective role in unfavorable conditions. The aim of this study was to examine the role of S-proteins in probiotic mechanism of action in the strain Lactobacillus brevis ZG1, where the strain of Lactobacillus helveticus M92 which contains S-proteins was used as a positive control, and the strain of Lactobacillus plantarum D13 which does not contain S-proteins was used as a negative control. It has been shown that the strain L. brevis ZG1 contains S-protein as well as proteins that are linked to them (eng. Surface-Layer Associated Proteins, SLAP), whose function is still unknown. It has also been proven that S-proteins of the strains L. helveticus M92 and L. brevis ZG1 have a protective role in the unfavorable conditions of the gastrointestinal tract. Furthermore, it has been found that the strains L. helveticus M92 and L. brevis ZG1 show proteolytic activity in skimmed milk, while L. plantarum D13 doesn't. The examination of the mucin-adhesion ability has shown significantly weaker adhesion ability after the removal of the S-layer proteins and SLAP proteins from the surface of the tested bacterial cells.

• Keywords: probiotici; S-proteini; SLAP; Lactobacillus brevis; adhezija
• Keywords (english): probiotics; S-layer proteins; SLAP; Lactobacillus brevis; adhesion
• Language: croatian
• URN:NBN: urn:nbn:hr:159:169892
• Study programme: Title: Molecular Biotechnology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka molekularne biotehnologije (magistar/magistra inženjer/inženjerka molekularne biotehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2017-04-27 11:42:36