Antimikrobno djelovanje bakterijskih sojeva izoliranih iz majčinog mlijeka

undergraduate thesis

• Title (english): Antimicrobial activity of bacterial strains isolated from breast milk
• Author: Lucija Leko
• 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: 2021-07-09, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Mnogi sojevi bakterija mliječne kiseline pokazuju antimikrobno djelovanje pa pronalaze potencijal kao starter kulture, biokonzervansi, probiotici ili kao zamjena antibioticima. Cilj ovog rada bio je ispitati antimikrobno djelovanje sojeva Lactobacillus plantarum KR19 i Lactobacillus plantarum MC19 izoliranih iz majčinog mlijeka prema srodnim bakterijama mliječne kiseline i prema patogenim bakterijama te njihovu kompetitivnu ekskluziju prema bakteriji E. coli 3014. Ispitivanje antimikrobnog djelovanja provedeno je trima metodama: metodom s rupama u agaru, metodom s dvostrukim slojem agara i turbidimetrijskom metodom. Rezultati pokazuju snažno inhibicijsko djelovanje oba soja prema patogenim bakterijama. Kompetitivna ekskluzija ispitana je pomoću Caco-2 stanične linije pri čemu su oba soja pokazala uspješnu inhibiciju adhezije E. coli, pri čemu je soj Lactobacillus plantarum MC19 imao jače djelovanje. Dobiveni rezultati ukazuju na potencijal primjene sojeva Lb. plantarum KR19 i Lb. plantarum MC19 kao probiotika.

Abstract (english)

Many strains of lactic acid bacteria exhibit antimicrobial activity, so they have potential as starter cultures, biopreservatives, probiotics or as a substitute for antibiotics. The aim of this research was to examine the antimicrobial activity of Lactobacillus plantarum KR19 and Lactobacillus plantarum MC19, strains isolated from breast milk, against related lactic acid bacteria and against pathogenic bacteria as well as competitive exclusion of E. coli 3014. Antimicrobial activity assay was carried out by three methods: agar well diffusion method, agar spot test method and broth microdilution assay. The results show a strong inhibition effect of both strains towards pathogenic bacteria. Competitive exclusion was tested using Caco-2 cell line, with both strains showing successful inhibition of E. coli adhesion, with the Lactobacillus plantarum MC19 strain having a stronger effect. The obtained results indicate potential for application of Lb. plantarum KR19 and Lb. plantarum MC19 strains as probiotics.

• Keywords: antimikrobno djelovanje; bakterije mliječne kiseline; bakteriocini
• Keywords (english): antimicrobial activity; bacteriocins; lactic acid bacteria
• Language: croatian
• URN:NBN: urn:nbn:hr:159:684102
• 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: 2021-07-15 09:53:51