Fenotip umjerene prednosti rasta enterobakterija nad Lactobacillus brevis L62 u mješovitim kulturama tijekom produljene stacionarne faze

master's thesis

• Title (english): Moderate growth advantage phenotype of enterobacteria over Lactobacillus brevis L62 in mixed cultures during prolong stationary phase
• Author: Martina Filipčić
• Mentor: Vesna Stehlik-Tomas (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for Fermentation and Yeast Technology); Zagreb
• Defense date and country: 2007-10-05, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Brojni mikroorganizmi koji nas okružuju većinu svog života provedu u stanju gladovanja. Rast i preživljavanje bilo koje vrste određeni su prisustvom drugih mikroorganizama i ekološkom interakcijom stanica. Cilj ovog rada bio je analizirati miješane kulture bakterija Lactobacillus brevis L62 i Escherichia coli K12, odnosno Salmonella enterica serotip Typhimurium za vrijeme uzgoja tijekom produljene faze gladovanja na ugljiku s ciljem razmatranja njihove koegzistencije i fenomena GASP (eng. Growth Advantage in Stationary Phase). Na osnovi rezultata je uočeno da je dugotrajan rast svih triju navedenih bakterijskih kultura moguć samo u tekućoj minimalnoj podlozi za rast laktobacila MML budući da u tekućoj kompletnoj hranjivoj podlozi MRS nakon šestodnevne kultivacije dolazi do odumiranja laktobacila. Dobiveni rezultati ukazuju na značajnu razliku u duljini preživljavanja enterobakterija u zasebnim kulturama i mješavinama s L. brevis L62. Desetodnevnom kultivacijom starih bakterijskih kultura enterobakterija i mlade bakterijske kulture laktobacila dolazi do pojave umjerenog fenomena GASP.

Abstract (english)

Unnumbered microorganisms that surround us spend most of their lives in state of starvation. The growth and survival of any species is determined by the presence of other microorganisms and cells ecological interactions. The aim of the study was to analyze mixed populations of Lactobacillus brevis L62 and Escherichia coli K12 or Salmonella enterica serovar Typhimurium during the prolonged period of carbon starvation due to the evaluation of their coexistence and the Growth Advantage in Stationary Phase (GASP) phenomenon. The results of this study demonstrate that growth in the prolonged stationary phase of all three bacteria species is possible only in minimal MML medium, because in rich MRS medium bacterial cells of L. brevis L62 lost viability after six days. The results also show a significant difference in survival of enterobacteria in separated and mixed cultures with L. brevis L62. During ten days cultivation of old bacterial cultures of enterobacteria and young bacterial culture of L. brevis L62 a moderate GASP phenomenon is observed.

• Keywords: Escherichia coli; fenomen GASP; Lactobacillus brevis; Salmonella enterica
• Keywords (english): Escherichia coli; GASP phenomenon; Lactobacillus brevis; Salmonella enterica
• Language: croatian
• URN:NBN: urn:nbn:hr:159:628487
• Study programme: Title: Biotechnology; specializations in: Biochemical Engineering; Course: Biochemical Engineering; Study programme type: university; Study level: graduate; Academic / professional title: diplomirani inženjer biotehnologije; smjer biokemijsko inženjerstvo (diplomirani inženjer biotehnologije; smjer biokemijsko inženjerstvo)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-09-06 08:01:07