Inhibicija modificiranega polietilena na rast mikrobnih celic

diplomsko delovisokošolskega strokovnega študijskega programa I. stopnje

Patricia Govedić (Author), Mateja Primožič (Mentor), Maja Leitgeb (Co-mentor)

Abstract

Namen diplomskega dela je proučiti antimikrobno učinkovitost modificiranega polietilena na rast mikrobnih celic. Antimikrobno učinkovitost modificiranih polietilenskih (PE) materialov smo testirali na štirih vzorcih (vzorci 1, 2, 3 in 4), ki so bili obdelani na različne načine in so vsebovali cinkov oksid (ZnO), kot potencialni inhibitor rasti mikrobnih celic. Kot slepi vzorec (vzorec, ki ne vsebuje inhibitorja rasti mikrobnih celic – ZnO) smo uporabili PE material brez aditivov (vzorec 0). Pri tem smo uporabili dve metodi za določevanje antimikrobne učinkovitosti testiranih materialov: klasično kontaktno metodo in metodo po ISO 22196:2007 standardu. Pri klasični kontaktni metodi gre za d inhibicije rasti mikrobnih celic na osnovi vizualnega zaznavanja in ne moremo natančno določiti stopnje inhibicije. To je enostavnejša, vendar manj natančna metoda. Pri uporabi metode po ISO 22196:2007 standardu pa lahko določimo stopnjo inhibicije, saj zajema indirektno števno metodo za določitev mikrobne populacije. Primerjali smo rezultate obeh metod in ugotovili, da klasična metoda ni dala zadovoljivih rezultatov, ker ni bilo mogoče zagotovo trditi ali gre za inhibicijo rasti mikrobnih celic ali ne. Z uporabo metode po ISO 22196:2007 pa smo lahko določili stopnjo inhibicije rasti mikrobnih celic na modificiranih materialih polietilena. Ugotovili smo, da je potrebno pripravljene razredčine vzorcev hraniti v ledeni kopeli (-4 °C), da preprečimo morebitno razmnoževanje mikroorganizmov v pripravljenih razredčinah pred pričetkom izvajanja testov. Prav tako je potrebno testne materiale (predvsem slepe vzorce, ki ne vsebujejo ZnO) pred ponovno uporabo sterilizirati v avtoklavu s postopkom suhe sterilizacije, saj z metodo, ki jo opisuje ISO 22196:2007 (spiranje materiala s 70 % etanolom) ne zagotavlja popolnega uničenja mikrobnih celic na površini testnih vzorcev. Z uporabo metode po ISO 22196:2007, kjer smo kot testna mikroorganizma uporabili Gram negativno bakterijo Escherichia coli (DSM 498) in Gram pozitivno bakterijo Staphylococcus aureus (DSM 346), smo dokazali, da vsi testni modificirani polietilenski materiali inhibirajo rast obeh bakterij.

Keywords

modificirani PE;inhibicija rasti mikrobnih celic;diplomske naloge;standards;modified polyethylene;inhibition on the growth of microbial cells;S. aureus;E. coli;

Data

Language:	Slovenian
Year of publishing:	2017
Typology:	2.11 - Undergraduate Thesis
Organization:	UM FKKT - Faculty of Chemistry and Chemical Engineering
Publisher:	[P. Govedić]
UDC:	66.097.8(043.2)
COBISS:	21050134
Views:	722
Downloads:	19
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Inhibition of modified polyethylene on the growth of microbial cells
Secondary abstract:	The purpose of this thesis is to study the antimicrobial efficieny of modified polyethylene on the growth of microbial cells. We tested the antimicrobial efficiency of modified polyethylene (PE) materials on four samples (sample 1, 2, 3 and 4) which were processed in different ways and they contained zinc oxide (ZnO) as a potential inhibitor of the growth of microbial cells. As a blank sample (sample, that does not contain the microbial cell growth inhibitor - ZnO) we used PE material without additives (sample 0). We used two methods to determine the antimicrobial efficienty of test materials: the classic contact method and the method according to ISO 22196:2007 standard. In the classic contact method it is about determination of inhibition of the growth of microbial cells based on visual perception and the degree of inhibition cannot be determined precisely. This is simplier but less accurate method. When using the method according to ISO 22196:2007 standard we can determine the degree of inhibition because it involves an indirect counting method for determining the microbial population. We compared the results of both methods and we found out that clasic contact method did not give the satisfied results because it was not possible to assert if there was an inhibition of the growth of microbial cells or not. Using the method ISO 22196:2007 we can determine the degree of inhibition of the growth of microbial cells on modified polyethylene materials. We found out that the prepared dilutions of samples must be stored on ice bath ( 4 °C) to prevent possible reproduction od microorganisms in prepared dilutions before the tests start. Test materials (especially blank samples that do not contain ZnO) also need to be sterilized in autoclave usig a dry sterilization before we use them again, because the method described by ISO 22196:2007 standard (washing the material with 70 % ethanol) does not ensure complete destruction of microbial cells on the surface of test samples. Using the method described by ISO 22196:2007 where we used as test microorganisms Gram negative bacteria Escherichia coli (DSM 498) and Gram positive bacteria Staphylococcus aureus (DSM 346), we proved that all test modified polyethylene matherials inhibit the growth of both bacteria
Secondary keywords:	ISO 22196:2007 standard;modified PE;inhibition on the growth of microbial cells;E. coli;S. aureus;
URN:	URN:SI:UM:
Type (COBISS):	Bachelor thesis/paper
Embargo end date (OpenAIRE):	2020-09-14
Thesis comment:	Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Pages:	IX, 28 str.
ID:	10852898