V nalogi smo preučevali fiziološke meje rasti in encimske aktivnosti štirih vrst črnih kvasovk iz rodu Aureobasidium (A. pullulans, A. melanogenum, A. subglaciale in A. namibiae). Zanimale so nas fiziološke meje rasti pri različnih temperaturah (0-42 °C) in koncentracijah soli (0-20 %) na trdnih agarnih gojiščih z glukozo ter encimske aktivnosti na različnih trdnih in tekočih gojiščih s kompleksnimi viri ogljika (ksilan, škrob, pektin, lignin, naftalen, celuloza, hitin, kazein, tributirin, taninska kislina, Tween-80). Po določitvi optimumov za posamezno vrsto smo preverjali encimske aktivnosti preučevanih vrst za posamezne kompleksne vire ogljika na trdnih in v tekočih gojiščih, pri slednjih s pomočjo barvila resazurin. Ugotovili smo, da kvasovke lahko rastejo pri koncentraciji do 19 % (m/V) NaCl (A. pullulans) in temperaturah med 0 °C (A. pullulans, A. subglaciale, A. namibiae) in 37 °C (A. melanogenum). Najboljše encimske aktivnosti smo zaznali pri gojiščih s ksilanom, ki so jim sledila gojišča s pektinom, škrobom in kazeinom. Rasti kvasovk ni bilo v gojiščih s hitinom in naftalenom. Na koncu smo s primerjavo proteinskih zaporedij izbranih vrst z zaporedji referenčnih sevov še potrdili obstoj genskih zapisov encimov za razgradnjo nekaterih substratov. Z nalogo smo določili temperaturne meje rasti in toleranco na NaCl ter vzpostavili metodo za nadaljnje raziskave vrst rodu Aureobasidium s pomočjo barvila resazurinWe have examined physiological growth limits and enzymatic activity of four species of black yeasts from the genus Aureobasidium (A. pullulans, A. melanogenum, A. subglaciale, A. namibiae). We have determined the growth limits on a solid agar media with glucose at two different variables, temperature (0-42 °C) and salt concentration (0-20 %) and examined enzymatic activity on solid and liquid culture media containing complex carbon sources (xylan, starch, pectin, lignin, naphtalene, celulose, chitin, casein, tributyrin, tanic acid, Tween 80). After the determination of growth limits we have checked enzymatic activity on solid and in liquid media, also by using resazurin dye in liquid media. We have found that yeasts can grow at salt concentrations to up to 19 % NaCl (A. pullulans) and the temperatures between 0 °C (A. pullulans, A. subglaciale, A. namibiae) and 37 °C (A. melanogenum). The highest enzyme activity was detected in the culture media containing xylan, pectin, starch and casein. The growth of yeasts did not occur in media with chitin and naphthalene. At the end we confirmed existence of some of the selected enzymes by comparing protein sequences of studied species with protein sequences from selected reference strains. This study characterized the temperature growth limits and tolerance to NaCl as well as optimized the resazurin dye method for further researches on species from the genus Aureobasidium
