Funkcionalna svojstva probiotičkih sojeva Bifidobacterium animalis subsp. lactis BB-12 i Bifidobacterium longum BB536

master's thesis

• Title (english): Functional properties of probiotic strains Bifidobacterium animalis subsp. lactis BB-12 and Bifidobacterium longum BB536
• Author: Maja Cepanec
• Mentor: Jagoda Šušković (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: 2014-09-30, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Mnogi bakterijski sojevi iz roda Bifidobacterium su okarakterizirani kao probiotici jer iskazuju pozitivne učinke na zdravlje domaćina. Cilj ovog rada je upravo ispitati funkcionalna svojstva dva bakterijskih soja: Bifidobacterium animalis subsp. lactis BB-12 i Bifidobacterium longum BB536. Ispitana je osjetljivost navedenih bakterijskih sojeva na različite antibiotike, te je ustanovljeno da primjenjeni antibiotici inhibiraju rast ovih bakterija, koje se stoga smatraju sigurnim s aspekta širenja rezistencije na antibiotike. Sojevi B. animalis subsp. lactis BB-12 i B. longum BB536 iskazuju antibakterijsko djelovanje što proizlazi iz antimikrobnog djelovanja prema intestinalnim patogenim bakterijama Escherichia coli 3014 i Salmonella enterica serovar Typhimurium FP1. Kako bi se ustanovilo moguće antagonističko međudjelovanje ovih probiotičkih sojeva i bakterija mliječne kiseline iz srodnih rodova, ispitano je i njihovo inhibicijsko djelovanje prema bakterijama Lactobacillus plantarum LMG 9206, Enteroccocus faecium ATCC 9430 i Lactococcus lactis subsp. lactis LMG 9450. Rezultati dobiveni turbidimetrijskom metodom dodatno potvrđuju inhibicijsko djelovanje odabranih bakterijskih sojeva prema test-mikroorganizmima i bakterijama mliječne kiseline. Ispitivani sojevi iskazuju i autoagregacijska i koagregacijska svojstva, koja mogu upućivati na uspješna adhezijska svojstva in vivo, te kompetitivnu ekskluziju nepoželjnih sojeva, te posljedično sprječavanja njihove kolonizacije u gastrointestinalnom traktu. Preliminarna istraživanja adhezije sojeva B. animalis subsp. lactis BB-12 i B. longum BB536 na specifične proteine ekstracelularnog matriksa, upućuju da ovi sojevi imaju mogućnost interakcije s kolagenom, fibronektinom i lamininom. Ispitana je i hidrolazna aktivnost, te prema rezultatima ispitivani sojevi imaju umjerenu aktivnost hidrolaze žučnih soli.

Abstract (english)

Many bacterial strains from Bifidobacterium genus are characterized as probiotics due to their positive effects on the health of the host. The aim of this work is to test the functional properties of two probiotic strains Bifidobacterium animalis subsp. lactis BB-12 and Bifidobacterium longum BB536. After analysis of antibiotic suspectibility testing, it was found that applied antibiotics inhibited the growth of these bacteria, which are therefore considered safe in terms of antibiotic resistance. The strains of B. animalis subsp. lactis BB-12 and B. longum BB536 show antibacterial activity, resulting from their antimicrobial activity against intestinal pathogenic bacteria Escherichia coli 3014 and Salmonella enterica serovar Typhimurium FP1. The inhibitory activity also against lactic acid bacteria Lactobacillus plantarum LMG 9206, Enteroccocus faecium ATCC 9430 and Lactococcus lactis subsp. lactis LMG 9450 was tested in order to investigate possible antagonistic interaction with probiotic strains of mentioned lactic acid bacteria. The results obtained from turbidimetry method further confirm the inhibitory effect of selected bacterial strains to the test-microorganisms and lactic acid bacteria. Strains show autoaggregation and coaggregation properties, which may indicate on a successful adhesion properties in vivo and competitive exlusion of undesirable strains, and consequently prevent their colonization in the gastrointestinal tract. Preliminary research of the adhesion capacties of the strains of B. animalis subsp. lactis BB-12 and B. longum BB536 to specific extracellular matrix proteins, indicate that these strains have the potential to interact with collagen, fibronectin and laminin. The bile salt hydrolase activity was also evaluated and the results showed that strains have moderate activity of bile salt hydrolase.

• Keywords: Bifidobacterium spp.; funkcionalnost; probiotici
• Keywords (english): Bifidobacterium spp.; functionality; probiotics
• Language: croatian
• URN:NBN: urn:nbn:hr:159:157803
• 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: Access restricted to students and staff of home institution
• Created on: 2017-05-02 11:29:45