20.500.12556/DKUM-96704 Analiza acetanom podobnih zunajceličnih polisaharidov z metodo UHPLC pri izbranih sevih ocetnokislinskih bakterij magistrsko delo Analysis of Acetan-Like Extracellular Polysaccharides in Selected Strains of Acetic Acid Bacteria by UHPLC Namen magistrske naloge je bil poiskati seve ocetnokislinskih bakterij (OKB), ki potencialno proizvajajo acetanom podobne zunajcelične polisaharide (ECPS), analizirati njihovo monosaharidno sestavo ter izbranim predstavnikom analizirati reološke lastnosti. V ta namen smo v raziskavo vključili 89 sevov OKB, ki smo jih izolirali v predhodnih raziskavah ali pridobili iz mednarodnih zbirk mikroorganizmov. Zunajcelične polisaharide smo izolirali s precipitacijo ter delno očistili z gelsko filtracijo in jih nadalje analizirali z ultra-visoko zmogljivo tekočinsko kromatografijo (UHPLC) z UV-detekcijo, sklopljeno s tandemsko masno spektrometrijo z elektrosprejno ionizacijo (ESI-MS/MS). Rabljenim gojiščem smo izmerili viskoznost, izoliranim potencialnim acetanom pa modula elastičnosti in viskoznosti z rotacijskim modularnim reometrom. Ugotovili smo, da na tvorbo acetanom podobnim polisaharidom vplivata čas gojenja bakterij in sestava gojišča. Monomerna sestava polisaharidov se je med sevi razlikovala, kar potrjuje njihovo raznolikost. Reološki testi pri izbranih acetanih so pokazali značilno pseudoplastično vedenje in viskoznost, primerljivo s komercialnim ksantanom. Ti rezultati nakazujejo, da so izbrani sevi OKB potencialni proizvajalci acetanom podobnim polisaharidov z uporabnimi reološkimi lastnostmi za živilsko in farmacevtsko industrijo. The aim of this master’s thesis was to identify strains of acetic acid bacteria (AAB) that potentially produce acetan-like extracellular polysaccharides (ECPS), to analyse their monosaccharide composition, and to characterise the rheological properties of selected representatives. For this purpose, 89 AAB strains were included in the study; these strains had either been isolated in previous research or obtained from international microbial culture collections. Extracellular polysaccharides were isolated by precipitation, partially purified by gel filtration, and subsequently analysed by ultra-high-performance liquid chromatography (UHPLC) with UV detection coupled with tandem mass spectrometry with electrospray ionisation (ESI–MS/MS). The viscosity of used culture media was measured, and the elastic and viscous moduli of the isolated acetan samples were determined using a rotational modular rheometer. We found that the production of acetan-like polysaccharides was influenced by both cultivation time and medium composition. The monomeric composition of the polysaccharides varied among strains, confirming their diversity. Rheological tests of selected acetan samples revealed characteristic pseudoplastic behaviour and viscosities comparable to those of commercial xanthan. These results indicate that the selected AAB strains are potential producers of acetan-like polysaccharides with useful rheological properties for applications in the food and pharmaceutical industries. ocetnokislinske bakterije acetanom podobni zunajcelični polisaharidi metoda UHPLC reologija. Acetic Acid Bacteria Extracellular Polysaccharides Acetan UHPLC Rheology true true false [T. Vidali] Slovenski jezik Angleški jezik Magistrsko delo/naloga 2026-01-24 07:53:43 2026-01-30 14:47:06 2026-01-31 03:16:03 0000-00-00 00:00:00 2026 0 Maribor 0 Maribor IV, 69 f. 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 582.23(043.2) 266855683 MAG_Vidali_Tjasa_2026.pdf MAG_Vidali_Tjasa_2026.pdf 1 626271DABBE36B5291F3C3BCA3D253BC 7e0fcf2a266532c35613c10fc7d47919afa2f4b49cb4db1f1949c49ba13a7fe1 9e5c6e14-f8f3-11f0-aa69-00155d00018d https://dk.um.si/Dokument.php?lang=slv&id=202512 Fakulteta za naravoslovje in matematiko 0 0 0