Proteolitička aktivnost odabranih funkcionalnih starter kultura

undergraduate thesis

• Title (english): Proteolytic activity of selected functional starter cultures
• Author: Anja Rodin
• Mentor: Blaženka Kos (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: 2013-06-26, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Cilj ovog rada bio je ispitati proteolitičku aktivnost autohtonih sojeva bakterija mliječne kiseline izoliranih iz hrvatskog tradicionalnog svježeg sira. Ispitana je metabolička aktivnost navedenih sojeva tijekom prekonoćnog uzgoja u mlijeku praćenjem promjene pH vrijednosti i koncentracije mliječne kiseline. Proteolička aktivnost je ispitana metodom difuzije u agar uz dodatak obranog mlijeka pri čemu su bakterijske kulture pokazale veću proteolitičku aktivnost od supernatanata kultura. SDS-PAGE metodom je ustanovljeno da Lb. fermentum A8 uzrokuje potpuno, a Ec. faecium A7 djelomično taloženje kazeina tijekom uzgoja u obranom mlijeku. Amplifikacijom gena koji kodiraju za proteaze prtH i prtH2 pomoću PCR metode dobiven je signal koji upućuje na prisutnost gena prtH2 kod soja Ec. faecium A7.

Abstract (english)

The aim of this study was to examine the proteolytic activity of autochthonous strains of lactic acid bacteria isolated from traditional Croatian soft cheese. The metabolic activity of these strains was examined during the overnight cultivation in milk by monitoring pH changes and the concentration of lactic acid. The proteolytic activity was tested by the agar diffusion method with the addition of skimmed milk, and the bacterial cultures showed a higher proteolytic activity than the culture supernatants. SDS-PAGE method showed that Lb. fermentum A8 causes complete and Ec. faecium A7 partial sedimentation of casein during the cultivation in skim milk. The amplification of the genes encoding for prtH and prtH2 proteases by PCR method created the signal which indicates the presence of prtH2 gene in Ec. faecium A7 strain.

• Keywords: bakterije mliječne kiseline; starter kulture; proteolitička aktivnost
• Keywords (english): lactic acid bacteria; starter cultures; proteolytic activity
• Language: croatian
• URN:NBN: urn:nbn:hr:159:241533
• 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: Access restricted to students and staff of home institution
• Created on: 2017-05-03 07:45:22