Razvoj dvovrsnog bakterijskog biofilma na granici voda-zrak

master's thesis

• Title (english): Development of two-species bacterial biofilm at air-liquid interface
• Author: Daniela Oršolić
• Mentor: Tomislav Ivanković (mentor)
• Committee member: Tomislav Ivanković (član povjerenstva)
• Committee member: Nenad Judaš (član povjerenstva)
• Committee member: Mirela Sertić Perić (član povjerenstva)
• Committee member: Vesna Petrović Peroković (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2018-04-20, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Bakterijski biofilm je kompleks građen od jedne ili češće više vrsta bakterija koje su ugrađene u matriks izvanstanične polimerne tvari (eng. extracellular polymeric substance EPS) kojeg same proizvode. Takvi bakterijski sustavi rade velike štete kako na medicinskoj opremi, tako i u ljudskim organizmima. Razumijevanje mehanizma formacije viševrsnog biofilma može znatno olakšati razvoj metoda za borbu protiv bakterijskih biofilmova u bolnicama, okolišu ili industrijama. Za istraživanje su korištene bakterije Staphylococcus aureus i Pseudomonas aeruginosa. Cilj istraživanja bio je napraviti model biofilma kojeg tvore te vrste bakterija, vizualizirati ga, usporediti rast bakterija na granici voda – zrak kod uzoraka u kojima se bakterijama mijenja medij s uzorcima u kojima se medij ne mijenja, te usporediti količine proizvedenog EPS-a. Obzirom da se pratila biomasa bakterija na pojedinim područjima na predmetnom stakalcu (vodeni medij, interfaza i zrak), te da se pratila količina nastalog EPS-a, bakterije su se bojile metodama po Gramu i Alcian blue radi bolje vidljivosti EPS-a i usporedbe uzoraka u navedena dva slučaja. Zaključeno je da se većina biofilma nalazi na interfazi, te da mijenjanje medija više pogoduje bakteriji P. aeruginosa, a ne mijenjanje medija više pogoduje bakteriji S. aureus. Bakterija S. aureus u oba slučaja nakon nekog vremena nadvlada bakteriju P. aeruginosa.

Abstract (english)

Bacterial biofilm is a complex of one or more species of bacteria that are embedded within an extracellular matrix composed of extracellular polymeric substances (EPS) produced by the cells. Such bacterial systems are doing significant damage both on medical equipment and in human organisms. Understanding the mechanism of multiple-species biofilm formation can ease the development of methods for bacterial biofilm prevention in hospitals, environment or industry. In this research, bacteria Staphylococcus aureus and Pseudomonas aeruginosa were used. The goal was to determine a model of biofilm created by these bacteria, visualize it, compare the growth of bacteria on air–liquid interface in systems in which the medium was continuously being replenished and when it is not, and compare the amount of produced EPS. Given that we monitored bacterial biomass in different areas (liquid medium, interface and air), and the amount of produced EPS, bacteria were Gram-stained, but also stained with Alcian blue to achieve better visibility of EPS and to compare samples in two aforementioned cases. It was concluded that biofilm is mostly located on the interface and that changing the medium was more beneficial to the growth of P. aeruginosa, while not changing the medium was more beneficial to the growth of S. aureus. Eventually, S. aureus outgrew P. aeruginosa in both cases.

• Keywords: biofilm; Pseudomonas aeruginosa; Staphylococcus aureus; interfaza; ekstracelularni matriks
• Keywords (english): biofilm; Pseudomonas aeruginosa; Staphylococcus aureus; interface; extracellular matrix
• Language: croatian
• URN:NBN: urn:nbn:hr:217:207770
• Study programme: Title: Integrated undergraduate and graduate university study of Biology and Chemistry Education; specializations in: Integrated undergraduate and graduate university study of Biology and Chemistry Education; Course: Integrated undergraduate and graduate university study of Biology and Chemistry Education; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: magistar/magistra edukacije biologije i kemije (magistar/magistra edukacije biologije i kemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2018-05-03 08:26:29