Utjecaj hladne plazme na stvaranje biofilma

undergraduate thesis

• Title (english): The effect of cold plasma tretament on the formation of biofilm
• Author: Valentina Magdić
• Mentor: Anet Režek Jambrak (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for Food Processes Engineering); Zagreb
• Defense date and country: 2017-06-13, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Svrha ovog rada je utvrditi učinak hladne plazme na stvaranje biofilma i inaktivaciju bakterijskih stanica Listeria innocua ATCC 33091. Uzorci su tretirani uz tri nezavisne varijable – frekvencija (60, 90, 120 Hz), vrijeme tretiranja (5 i 10 min) te polaritet (+/-). Eksperiment je proveden s dva tipa hladne plazme, a to su plazma generirana u mjehurićima te tekućinska plazma bez miješanja. Potpuna inaktivacija postignuta je pri frekvenciji (90 Hz) te najduljem vremenskom tretmanu (10 min) pri pozitivnom polaritetu plazme generirane u mjehurićima (6.20 log10 CFU/mL). Najbolji učinak s obzirom na stvaranje biofilma je također postignut najduljim tretiranjem (10 min) uz najvišu frekvenciju (120 Hz) pri pozitivnom polaritetu plazme generirane u mjehurićima (90.16%). Statističkom obradom utvrđena je statistička značajnost (p<0.05) frekvencije te kombinacija frekvencije i polariteta na stvaranje biofilma. Za razliku od toga, promatranjem stope redukcije nije utvrđen niti jedan čimbenik koji bi statistički značajno utjecao (p>0.05).

Abstract (english)

The aim of this study is to determine the effect of cold plasma on formation of biofilm and inactivation rate of Listeria innocua ATCC 33091. The samples were treated using three independent variables – frequency (60, 90, 120 Hz), time (5 and 10 mins) and polarity (+/-). The experiment was conducted with two types of cold plasma: plasma generated in the bubbles and liquid plasma without stirring. Complete inactivation was achieved at the frequency value of 90 Hz and the longest treatment time (10 min) at the positive polarity of plasma generated in the bubbles (6.20 log10 CFU/mL). The best effect on biofilm formation is also at the longest time of treating (10 mins) with the highest frequency (120 Hz) and the positive polarity of plasma generated in the bubbles (90.16 %). Statistical analysis determined the statistical significance (p<0.05) of frequency and a combination of frequency and polarity on the formation of biofilm. None of the factors had a statistically significant effects on the reduction rate (p>0.05).

• Keywords: bakterija; biofilm; hladna plazma; inaktivacija; polaritet
• Keywords (english): bacterium; biofilm; cold plasma; inactivation; polarity
• Language: croatian
• URN:NBN: urn:nbn:hr:159:084771
• Study programme: Title: Food Technology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka prehrambene tehnologije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka prehrambene tehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2017-06-13 06:47:50