Određivanje bakteriocinske aktivnosti Lactobacillus sojeva prema Staphylococcus aureus 3048 i Listeria monocytogenes ATCC 19111

undergraduate thesis

• Title (english): Determination of bacteriocinogenic activity of Lactobacillus strains according to Staphylococcus aureus 3048 and Listeria monocytogenes ATCC 19111
• Author: Ena Makovec
• Mentor: Jasna Novak (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: 2017-07-07, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Tema ovoga rada bila je ispitati antimikrobno djelovanje autohtonih izolata hrvatskog tradicionalnog sušenog sira L. casei M2, L. casei M3, L. plantarum M4, L. plantarum M5, L. casei MA1, L. plantarum MA2 i L. plantarum MA3 prema bakterijama učestalim kontaminatima hrane. Budući da bakterije mliječne kiseline imaju važnu ulogu u konzerviranju i osiguravanju mikrobiološke kvalitete fermentiranog proizvoda zbog proizvodnje različitih ekstracelularnih metabolita i antimikrobnog djelovanja, navedeni bakterijski sojevi se ispituju kao potencijalne starter kulture za proizvodnju sireva. Metodom difuzije u agar i metodom s dvostrukim slojem agara ispitano je antibakterijsko djelovanje odabranih 7 Lactobacillus sojeva prema test-mikroorganizmima Staphylococcus aureus 3048 i Listeria monocytogenes ATCC 19111. Metoda difuzije u agar pokazala je da su odabrani sojevi uspješno inhibirali rast S. aureus 3048. Slično, svi Lactobacillus sojevi su iskazali antagonističko djelovanje prema L. monocytogenes ATCC 19111, izuzev sojeva L. plantarum MA2 i MA3. Metodom s dvostrukim slojem agara je dodatno potvrđeno potencijalno bakteriocinsko djelovanje prema bakterijama L.monocytogenes ATCC 19111 i S. aureus 3048.

Abstract (english)

The subject of this work was to examine the antimicrobial activity of autochtonous isolates of the traditional Croatian dry cheese, L. casei M2, L. casei M3, L. plantarum M4, L. plantarum M5, L. casei MA1, L. plantarum MA2 and L. plantarum MA3, towards bacteria that are frequent food contaminants. Since lactic acid bacteria play an important role in conserving and securing the microbiological quality of the fermented product, due to the production of different extracellular metabolites and antimicrobial activity, these bacterial strains were tested as potential starter cultures for the cheese production. The antibacterial activity of the 7 selected Lactobacillus strains towards the test-microorganisms, Staphylococcus aureus 3048 and Listeria monocytogenes ATCC 19111, has been tested by the diffusion method in the agar and the agar-spot-test method. The diffusion method into the agar showed that the selected strains have successfully inhibited the growth of S. aureus 3048. Similar to that, all of the Lactobacillus strains showed antagonistic action towards L. monocytogenes ATCC 19111, with the exception of L. plantarum MA2 and MA3 strains. The agar-spot-test method further confirmed the potentially bacteriocinogenic activity towards L.monocytogenes ATCC 19111 and S. aureus 3048.

• Keywords: antimikrobna aktivnost; bakteriocini; Lactobacillus sojevi
• Keywords (english): antimicrobial activity; bacteriocins; Lactobacillus strains
• Language: croatian
• URN:NBN: urn:nbn:hr:159:710926
• 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: 2017-07-07 09:51:09