Ispitivanje probiotičkih svojstava bakterija mliječne kiseline izoliranih iz majčinog mlijeka

undergraduate thesis

• Title (english): Investigation of probiotic properties of lactic acid bacteria isolated from breast milk
• Author: Lucija Vuletić-Antić
• Mentor: Andreja Leboš Pavunc (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: 2021-07-09, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Cilj ovog završnog rada bio je ispitati svojstva bakterija mliječne kiseline Lactobacillus plantarum KR19, Enterococcus faecium KR20, L. fermentum MC1, E. faecium MC13, L. plantarum MC19, L. plantarum MB7, L. plantarum MB15, L. plantarum MB18 i L. plantarum RS10, izoliranih iz majčinog mlijeka. Ispitana su svojstva preživljavanja u simuliranim uvjetima gastointestinalnog trakta i tijekom procesa liofilizacije, sposobnost autoagregacije te adhezije na heksan. Ispitivanja tih svojstava važna su zbog moguće primjene ovih bakterija kao probiotičkih. Većina je sojeva postigla zadovoljavajući postotak preživljavanja tijekom izlaganja simuliranim uvjetima gastrointestinalnog trakta, a najbolji postotak preživljavanja u uvjetima simuliranog želučanog soka postignut je sa sojem MC1 i iznosio je 86,08 %, dok je najbolji postotak preživljavanja uvjeta simuliranog soka tankog crijeva postignut sa sojem MC19 te je iznosio 83,41 %. Većina sojeva u visokom broju preživljava uvjete liofilizacije s obranim mlijekom kao lioprotektorom, od kojih soj MB15 preživljava u najvećem broju. Najveću sposobnost autoagregacije pokazao je soj MB18, čiji je postotak autoagregacije iznosio 97,05 %. Sojevi KR19, MC19 i RS10 pokazuju hidrofilna svojstva površine, dok je površina ostalih sojeva hidrofobna.

Abstract (english)

The aim of this work was to examine the properties of bacteria strains Lactobacillus plantarum KR19, Enterococcus faecium KR20, L. fermentum MC1, E. faecium MC13, L. plantarum MC19, L. plantarum MB7, L. plantarum MB15, L. plantarum MB18 and L. plantarum RS10 isolated from breast milk. The properties that were examined were the survival of bacteria in the simulated conditions of the gastrointestinal tract and during the freeze-drying process, as well as autoaggregation ability and adhesion ability to hexane. These properties are important for the potential use of these strains as probiotics. Most strains showed the significant ability of survival in the simulated conditions in the gastrointestinal tract, of which strain MC1 demonstrated the best result with 86.08 % survival rate in the simulated conditions in the stomach and strain MC19 demonstrated the best results with 83.41 % survival rate in the simulated conditions in the small intestine. Most strains survived the freeze-drying process better with skimmed milk as lyoprotectant, with strain MB15 surviving in the highest number. Strain MB18 exhibited the best autoaggregation ability with a percentage of autoaggregation of 97.05 %. The surface of strains KR19, MC19 and RS10 was shown to be hydrophilic, while the other strains have hydrophobic surfaces.

• Keywords: majčino mlijeko; bakterije mliječne kiseline; probiotici
• Keywords (english): breast milk; lactic acid bacteria; probiotics
• Language: croatian
• URN:NBN: urn:nbn:hr:159:962119
• Study programme: Title: Biotechnology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka biotehnologije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka biotehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2021-07-19 10:42:43