Assimilation of cholesterol and prebiotic substrates with selected probiotic strains of Lactobacillus species

master's thesis

• Title: Asimilacija kolesterola i prebiotičkih supstrata s odabranim probiotičkim sojevima Lactobacillus vrsta
• Author: Sonja Jasić
• 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: 2012-07-12, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Na temelju glavnog zahtjeva za izbor probiotičkih sojeva, njihovog preživljavanja u uvjetima gastrointestinalnog trakta (GIT), odabrana su 4 soja Lactobacillus vrsta za daljnja istraživanja u okviru probiotičkog koncepta: Lactobacillus sucicola/uvarum/capillatus BGGO7-28, Lactobacillus pentosus/paraplantarum/plantarum BGGO5-3, Lactobacillus casei BGGO5-7 i Lactobacillus rhamnosus BGGO5-47. Osobito visok stupanj preživljavanja pri pH vrijednosti simuliranog želučanog soka 2 i u simulaciji soka tankog crijeva, pokazao je bakterijski soj BGGO5-3. Ispitivana je i osjetljivost odabranih probiotičkih sojeva na različite skupine antibiotika kako bi se isključila mogućnost širenja antibiotičke rezistencije. Testom koegzistencije je ispitana i dokazana mogućnost rasta odabranih probiotičkih sojeva kao združene kulture. Također, ispitana je asimilacija različitih prebiotičkih supstrata: manitola, laktuloze, raftiloze i inulina. Prema dobivenim rezultatima, odabrani probiotički sojevi najbolje rastu s manitolom i laktulozom kao izvorima ugljika. Mikrobnom adhezijom u otapalima provedenom s etil-acetatom, heksanom i kloroformom, ustanovljena su svojstva površine stanica ispitivanih probiotičkih sojeva. Asimilacija kolesterola s odabranim sojevima je bila podjednaka za sve ispitivane sojeve, a provedena je uz dodatak žučnih soli, jer su one prirodno prisutne u tankom crijevu gdje bi probiotičke bakterije trebale asimilirati kolesterol.

Abstract (english)

Based on the main requirements for the selection of probiotic strains, their survival under conditions of the gastrointestinal tract (GIT), 4 strains of Lactobacillus species were selected for further research in the probiotic concept: Lactobacillus sucicola/uvarum/capillatus BGGO7-28, Lactobacillus pentosus/ paraplantarum /plantarum BGGO5 -3, Lactobacillus casei BGGO5-7 and Lactobacillus rhamnosus BGGO5-47. Bacterial strain BGGO5-3 showed particularly high level of survival at pH values of simulated gastric juice 2 an simulation of the small intestine juice. Sensitivity of selected probiotic strains to different groups of antibiotics was investigated to rule out the possibility of spreading antibiotic resistance. Coexistence test has proved the ability of selected probiotic strains to grow as a joint culture. The assimilation of various prebiotic substrates: mannitol, lactulose, raftilose and innulin was also examined. According to the results, the selected probiotic strains grow best with mannitol and lactulose as a carbon source. Microbial adhesion to solvents carried out with ethylacetate, hexane and chloroform has indicated cell surface properties of the tested probiotic strains. Assimilation of cholesterol with the selected strains was similar for all tested strains and was conducted with the addition of bile salts, as they are naturally present in the small intestine where the probiotic bacteria should assimilate cholesterol.

• Keywords: simulirani GIT uvjeti; antibiotička rezistencija; koegzistencija; asimilacija prebiotika; asimilacija kolesterola
• Keywords (english): simulated GIT conditions; antibiotic resistance; coexistence; prebiotic assimilation; cholesterol assimilation
• Language: croatian
• URN:NBN: urn:nbn:hr:159:592949
• Study programme: Title: Molekularna biotehnologija; Study programme type: sveučilišni; Study level: diplomski; 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: Restricted access
• Created on: 2017-05-09 08:42:16