Antimikrobna aktivnost zelenih otapala iz skupine estera

master's thesis

• Title (english): Antimicrobial activity of green solvents from the ester group
• Author: Andrea Gradinšćak
• Mentor: Mirna Mrkonjić Fuka (mentor)
• Committee member: Mirna Mrkonjić Fuka (predsjednik povjerenstva)
• Committee member: Marko Vinceković (član povjerenstva)
• Committee member: Anet Režek Jambrak (član povjerenstva)
• Committee member: Irina Tanuwidjaja (član povjerenstva)
• Granter: University of Zagreb; Faculty of Agriculture; (Microbiology); Zagreb
• Defense date and country: 2021-09-29, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Agronomy

Abstract

Ubrzani razvoj poljoprivredne proizvodnje značajno doprinosi zagađenju okoliša. Iskorištavanje poljoprivrednih nusprodukata, poput biljnih ostataka, u kombinaciji s energetski manje zahtjevnim procesima i ekološki prihvatljivim otapalima, temelj su održivog razvoja. Brojne biljke izvor su bioaktivnih spojeva s antimikrobnom aktivnošću. Upotreba „zelenih otapala“ iz skupine estera, kao što su dimetil-karbonat i etil-acetat, za ekstrakciju bioaktivnih spojeva iz biljaka, u praksi je dugi niz godina. Obzirom da se dosadašnja istraživanja bave ispitivanjem antimikrobne aktivnosti produkata ekstrakcije, nužno je ispitati i antimikrobni učinak samih otapala na različite grupe mikroorganizama. Stoga je cilj ovog rada ispitati antimikrobni utjecaj navedenih otapala na tri korisna autohtona izolata bakterija mliječne kiseline izoliranih iz fermentiranih namirnica kao i na sedam potencijalno patogenih bakterijskih vrsta i uzročnika kvarenja hrane. Ispitane su koncentracije otapala u rasponu 1,56-100% te su utvrđene minimalne inhibitorne (MIK) i minimalne baktericidne (MBK) koncentracije dviju različitih biomasa bakterija (103 i 106 CFU/mL). Nadalje, ispitan je i utjecaj niskih koncentracija otapala (ispod MIK i MBK vrijednosti) na brojnost ispitivanih izolata. Utvrđeno je da oba otapala djeluju inhibitorno i na korisne i na potencijalno patogene bakterije te se zbog toga ne preporuča njihova primjena u obliku aditiva u fermentiranim namirnicama, no predstavljaju potencijal u primjeni kao otapala za ekstrakciju bioaktivnih spojeva u smislu sinergističkog antimikrobnog djelovanja s ekstrahiranim bioaktivnim spojevima.

Abstract (english)

Accelerated development of agricultural production significantly contributes to environmental pollution. Utilization of agricultural by-products, such as crop residues, combined with less energy-intensive processes and environmentally friendly solvents, are the foundation of sustainable development. Numerous plants are a source of bioactive compounds with antimicrobial activity. The use of "green solvents" from the group of esters, such as dimethyl-carbonate and ethyl-acetate, for the extraction of bioactive compounds from plants has been in practice for many years. Given that previous research has examined the antimicrobial activity of extraction products, it is necessary to examine the antimicrobial effect of the solvents themselves on different groups of microorganisms. Therefore, the aim of this study is to examine the antimicrobial effect of these solvents on three useful indigenous isolates of lactic acid bacteria isolated from fermented foods as well as on seven potentially pathogenic bacterial species and food spoilage agents. Solvent concentrations in the range of 1.56-100% were tested and minimum inhibitory (MIC) and minimum bactericidal (MBK) concentrations of two different biomass (103 and 106 CFU / mL) were determined. Furthermore, the influence of low solvent concentrations (below MIK and MBK values) on the number of tested isolates was examined. It has been established that both solvents have an inhibitory effect on both beneficial and potentially pathogenic bacteria, and therefore their use in the form of food additives is not recommended, but represent potential in use as solvents for extraction of bioactive compounds in terms of synergistic antimicrobial activity with extracted bioactive compounds.

• Keywords: zelena otapala; esteri; antimikrobna aktivnost; MIK; MBK
• Keywords (english): green solvents; esters; antimicrobial activity; MIC; MBC
• Language: croatian
• URN:NBN: urn:nbn:hr:204:711851
• Study programme: Title: Agroecology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/ magistra inženjer/inženjerka agroekologije (magistar/ magistra inženjer/inženjerka agroekologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to authenticated users
• Created on: 2021-12-08 09:10:36