Quantification of yeasts and moulds in food with SimPlate

V diplomskem delu smo proučevali primerljivost alternativne metode za določanje kvasovk in plesni (SimPlate Y&M CI) s klasično metodo za kvantifikacijo kvasovk in plesni na gojišču DRBC (gojišče z barvilom dikloran rdeče in bengal ter kloramfenikolom). Alternativna metoda, ki je od klasične hitrejša ter enostavnejša, bi lahko na področju živilstva zelo pripomogla k pravočasnemu odkrivanju kvarljivcev živil. Mikrobiološko preiskavo smo izvedli z naravno kontaminiranim vzorcem zgornjesavinjskega želodca ter umetno kontaminiranim vzorcem zgornjesavinjskega želodca, ki smo mu dodali kvasovke vrste Saccharomyces cerevisiae v koncentraciji 108 CFU/ml. Po podaljšani inkubaciji (8 dni) alternativna in klasična metoda kvantifikacije kvasovk in plesni v živilu nista dali primerljivih rezultatov. Možen in najbolj verjeten vzrok so bile spremembe dehidriranega gojišča SimPlate. Nadaljnje raziskave z metodo SimPlate Y&M CI za določanje kvasovk in plesni v živilu bi vključevale izvedbo mikrobioloških preiskav z več različnimi živili (npr. surova živila, izdelkitekoča poltrdna in trdna živila) in z različnimi mikroorganizmi (npr. različne vrste kvasovk, plesni, mešane kulture, ki bi bile naravno prisotne in dodane v majhnem ter velikem številu) in več ponovitvami.The aim of thesis was to determine the comparability of an alternative method for the quantification of yeasts and molds (SimPlate Y&M CI) with the traditional method for quantification of yeasts and molds on DRBC agar (dichloran rose-bengal chloramphenicol agar). SimPlate Y&M CI as an alternative method is faster and simpler than the traditional method and therefore could contribute significantly to faster detection of spoilage yeasts and molds in food. Microbiological tests were performed on a naturally contaminated sample of Zgornjesavinjski želodec and an artificially contaminated sample of Zgornjesavinjski želodec to which Saccharomyces cerevisiae was added at a concentration of 108 CFU/ml. After a prolonged incubation of 7 days, the alternative and traditional methods did not give comparable results. The possible and most probable cause for the results obtained is changes in the dehydrated SimPlate medium. Further investigation of the SimPlate Y&M CI method for the quantification of yeasts and molds in foods should include microbiological tests on several different foods (e.g. raw foods, food products, liquid, semi-solid and solid foods) and with different microorganisms (different yeasts, different molds or mixed cultures naturally present and added at lower and higher concentrations) and several replicates