Tvorba in karakterizacija E. coli biofilmov v kontinuirnem sistemu

magistrsko delo

Elfi Birsa (Author), Aleš Podgornik (Mentor), Igor Plazl (Thesis defence commission member), Gabriela Kalčíková (Thesis defence commission member)

Abstract

Bakterijski biofilm predstavlja skupnost bakterijskih celic, pritrjenih na površini substrata in obdanih z zunajceličnimi polimernimi snovmi (EPS), kjer celice izkazujejo popolnoma drugačno rast, metabolno aktivnost in odpornost kot planktonske celice. Ta večplastna bakterijska rast pogosto povzroča nemalo težav na številnih področjih povezanih s hrano, vodo, farmacijo in medicino. Izkoreninjenje biofilma je izjemno težko, zaradi manjše metabolne aktivnosti celic v notranjosti biofilma in s tem manjši dovzetnosti za delovanje antibiotikov in drugih protimikrobnih sredstev. Poleg tega pa tudi sam biofilm deluje kot fizična ovira za dostop do bakterij. Zaradi velike odpornosti biofilmskih bakterij, so potrebne nove metode za njihovo odstranjevanje, in bakteriofagi bi lahko bili zanimiva alternativa, saj predstavljajo naravne ubijalce bakterij. Pri eksperimentalnem delu smo vzpostavili kontinuiren sistem z mešalnim in cevnim bioreaktorjem, kjer smo uspešno tvorili E. coli biofilm. Za karakterizacijo nastalega biofilma po 2 h tvorbe smo cevko intenzivno spirali. Rezultati so pokazali, da se celice zadržijo v cevnem bioreaktorju, kjer imamo prisotne adsorbirane celice na notranji steni cevke, ki so viabilne, vendar mirujoče, ter proste planktonske celice, ki se sproščajo iz biofilma in potujejo vzdolž cevke. Pokazali smo, da so se bakteriofagi sposobni adsorbirati in inficirati biofilmske bakterije, njihova propagacija pa ne poteče vse dokler biofilm ni izpostavljen bolj ugodnim okoliščinam.

Keywords

Escherichia coli;bakterijski biofilmi;tvorba biofilma;bakteriofag T4;interakcije bakteriofag-biofilm;cevni bioreaktor;magistrska dela;

Data

Language:	Slovenian
Year of publishing:	2021
Typology:	2.09 - Master's Thesis
Organization:	UL FKKT - Faculty of Chemistry and Chemical Technology
Publisher:	[E. Birsa]
UDC:	602.3:578.347(043.2)
COBISS:	89914883
Views:	228
Downloads:	44
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Formation and characterization of E.coli biofilms in a continuous system
Secondary abstract:	Bacterial biofilm represents a community of bacterial cells attached to the surface of the substrate and surrounded by extracellular polymeric substances (EPS), where cells show completely different growth, metabolic activity and resistence than planktonic cells. This multilayered bacterial growth often causes problems in many areas related to food, water, pharmacy and medicine. Eradication of biofilm is extremely difficult, due to the lower metabolic activity of cells inside the biofilm and thus less susceptibility to antibiotics and other antimicrobial agents. Moreover, the biofilm itself acts as a physical barrier to access the bacteria. Due to the high resistance of biofilm bacteria, new methods aimed at aliminating them are needed, and bacteriophages could be an interesting alternative as they are natural killers of bacteria. In the experimental work we successfully formed E.coli biofilm in a continuous custom build system with mixed and tubular bioreactor. To asses the resulting biofilm after 2 h of formation, the tube was intensely washed. The results have shown that the cells are retained in the tubular bioreactor, consisting of adsorbed cells on the inner wall of the tube, that are viable, but dormant, and free planktonic cells dispersed from the biofilm and traveling along the tube. We have shown that bacteriophages are capable of adsorbing and infecting biofilm bacteria, but their propagation doesn't continue until the biofilm is exposed to more favorable environment.
Secondary keywords:	bacterial biofilm;biofilm formation;bacteriophage T4;tubular bioreactor;
Type (COBISS):	Master's thesis/paper
Study programme:	1000376
Thesis comment:	Univ. v Ljubljani, Fak. za kemijo in kemijsko tehnologijo, smer Kemijsko inženirstvo
Pages:	53 str.
ID:	14054291