Antifungalni učinak gama zračenja na mikobiotu celuloznih materijala

master's thesis

• Title (english): Antifungal effect of gamma-irradiation on mycobiota of cellulose materials
• Author: Martina Kriletić
• Mentor: Maja Šegvić Klarić (mentor)
• Committee member: Maja Šegvić Klarić (predsjednik povjerenstva)
• Committee member: Ana-Marija Domijan (član povjerenstva)
• Committee member: Daniela Jakšić Despot (član povjerenstva)
• Granter: University of Zagreb; Faculty of Pharmacy and Biochemistry; (Department of microbiology); Zagreb
• Defense date and country: 2017-04-28, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Pharmacy; Pharmacy

Abstract

Plijesni imaju ključnu ulogu u destrukciji predmeta kulturne baštine. Međutim, njihovu destruktivnu aktivnost učinkovito i sigurno zaustavlja gama zračenje.
U ovom radu istraživan je utjecaj gama zračenja na prirodnu mikobiotu papira i platna, te na odabrane vrste inokuliranih kolonizatora (Aspergillus jensenii, Cladosporium sphaerospermum i Trichoderma harzianum). Uzorci su tretirani pomoću izvora u Laboratoriju za radijacijsku kemiju u dozimetriju (LRKD) Instituta Ruđer Bošković (IRB). Primijenjena je apsorpcijska doza od 50 kGy u dvije brzine zračenja (0,1 i 9,8 Gy/s). Mikrobiološka analiza ozračenih uzoraka provedena je 0., 7., 14. i 28. dan nakon zračenja. Iz dobivenih rezultata vidljivo je da apsorpcijska doza od 50 kGy gotovo potpuno uništava sve vrste plijesni (prirodnu mikobiotu, odnosno namjerno inokulirane primarne, sekundarne i tercijarne kolonizatore) i njihove spore na ozračenim uzorcima, bez obzira na brzinu zračenja i bez pojave recidiva. Izuzetak je porast po jedne kolonije sterilnog micelija nakon 7., 14. i 28. dana nakon zračenja. Ovakvi rezultati su očekivani s obzirom da je 25 kGy referentna doza sterilizacije zračenjem. Problem kod visokih doza gama zračenja je što do izražaja dolaze nedostaci samog zračenja. Naime, prema literaturnim podacima mijenjaju se kemijska, fizička i mehanička svojstva papira, što rezultira dodatnim oštećenjima ozračenih materijala. Dakle, u postupku zaštite predmeta kulturne baštine nužan je interdisciplinarni znanstveni pristup u kojem se uz mikrobiološke analize mora proučavati utjecaj zračenja na organski materijal na molekularnoj razini.

Abstract (english)

Fungi play a fundamental role in biodeterioration of cultural heritage. However, fungal growth is effectively and safely stopped by gamma radiation.
This research evaluated the effect of gamma radiation on natural mycobiota of paper and glue coated linen as well as on the selected species of inoculated fungal colonies (Aspergillus jensenii, Cladosporium sphaerospermum and Trichoderma harzianum). Inoculated samples have been treated by the Laboratory for radiation chemistry and dosimetry of Ruđer Bošković Institute source. Dose of 50 kGy was applied at two dose rates (0,1 and 9,8 Gy/s). Microbiological analysis was made on 0th, 7th, 14th and 28th day after treatment.The results have shown that dose of 50 kGy almost completely destroys all fungal colonies (naturally occurring mycobiota and artificially inoculated primary, secondary and tertiary colonizers) and their spores regardless of the applied dose rate, except appearance of one colony of sterile mycelia on 7th, 14th and 28th day upon irradiation. Considering that 25 kGy is defined as a reference dose of terminal sterilization, this outcome was expected. A downside of a high dose of gamma radiation is a change in chemical, physical and mechanical properties of the cellulose materials.To conclude, an interdisciplinary scientific approach including microbial as well as molecular analysis of organic material after radiation should be used in order to conserve cultural heritage.

• Keywords: kulturna baština; gama zračenje; plijesni
• Keywords (english): cultural heritage; gamma radiation; fungi
• Language: croatian
• URN:NBN: urn:nbn:hr:163:705780
• Study programme: Title: Pharmacy; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: magistar/magistra farmacije (magistar/magistra farmacije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2017-11-22 14:12:06