Enzymatic Characterization Of Yeast Strains Originated From Traditional Mihalic Cheese

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Identification And Enzymatic Characterization Of The Yeasts Isolated From Erzincan Tulum Cheese

In this study, 146 yeast isolates were obtained from 45 Erzincan tulum cheese samples. By using API ID 32C test system and some complementary morphological, physiological and biochemical tests, 121 of the isolates could be identified at species level, while 12 of them were identified at genus level. The identified yeast isolates belonged to six different genera which were Candida, Geotrichum, Kluyveromyces, Pichia, Saccharomyces and Zygosaccharomyces. The most aboundant species was C. lambica, followed by C. zeylanoides, C. famata var. famata, G. candidum and C. kefyr. Enzymatic characterization of the strains was determined by using API-ZYM test system. All of the isolates had leucin arylamidase activity. Eight strains belonging to S. cerevisiae, Z. mellis, G. candidum and P fermentans were found to have high leucin arylamidase activities. Most of the isolates had beta-galactosidase, acid phosphatase and esterase lipase (C8) activities. Eight investigated C. lambica strains had high acid phosphatase activities. Such enzymatic properties of investigated yeast isolates could be fundamental factor for their application as starter culture candidates in production of Erzincan tulum cheese. It was demonstrated that the strain C. lambica T103 had superior enzymatic characteristics with the potential to be used in further technological investigations as an adjunct starter.Wo

Identifikacija i enzimatska karakterizacija kvasaca izoliranih iz Erzincan tulum sira

In this study, 146 yeast isolates were obtained from 45 Erzincan tulum cheese samples. By using API ID 32C test system and some complementary morphological, physiological and biochemica tests, 121 of the isolates could be identified at species level, while 12 of them were identified at genus level. The identified yeast isolates belonged to six different genera which were Candida, Geotrichum, Kluyveromyces, Pichia, Saccharomyces and Zygosaccharomyces. The most aboundant species was C. lambica, followed by C. zeylanoides, C. famata var. famata, G. candidum and C. kefyr. Enzymatic characterization of the strains was determined by using API-ZYM test system. All of the isolates had leucin arylamidase activity. Eight strains belonging to S. cerevisiae, Z. mellis, G. candidum and P. fermentans were found to have high leucin arylamidase activities. Most of the isolates had β-galactosidase, acid phosphatase and esterase lipase (C8) activities. Eight investigated C. lambica strains had high acid phosphatase activities. Such enzymatic properties of investigated yeast isolates could be fundamental factor for their application as starter culture candidates in production of Erzincan tulum cheese. It was demonstrated that the strain C. lambica T103 had superior enzymatic characteristics with the potential to be used in further technological investigations as an adjunct starter.U ovom istraživanju izolirano je 146 kvasaca iz 45 uzoraka Erzincan tulum sira. Pomoću API ID 32C test sustava te nekih komplementarnih morfoloških, fizioloških i biokemijskih testova, 121 izolat kvasca potencijalno je identificiran na razini vrste, dok je 12 izolata identificirano na razini roda. Utvrđeno je da izolirani kvasci pripadaju sljedećim rodovima: Candida, Geotrichum, Kluyveromyces, Pichia, Saccharomyces i Zygosaccharomyces. Najveći broj izolata pripadao je vrstama C. lambica, C. zeylanoides, C. famata var. famata, G. candidum i C. kefyr. Enzimatska karakterizacija sojeva utvrđena je pomoću API-ZYM sustava. Svi izolati pokazali su leucin arilamidaznu aktivnost. Za osam izolata koji pripadaju vrstama S. cerevisiae, Z. mellis, G. candidum i P. fermentans utvrđeno je da posjeduju visoke aktivnosti leucin arilamidaze. Većina izolata imala je β-galaktozidaznu, kiselu fosfataznu i esteraznolipaznu (C8) aktivnost. Osam istraživanih sojeva C. lambica imalo je visoke aktivnosti kisele fosfataze. Takva enzimatska svojstva istraživanih kvasaca mogla bi biti temelj za njihovu potencijalnu primjenu u pripremi starter kultura u proizvodnji Erzincan tulum sira. Dodatno je utvrđeno da soj C. lambica T103 ima izuzetna enzimatska svojstva koja bi se u daljnjim tehnološkim istraživanjima trebala ispitati te uvrstiti kao potencijalni soj u pripremi starter kulture navedenog sira

Performance and Cost Analysis of Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry for Routine Identification of Yeast▿

Matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) mass spectrometry was compared to phenotypic testing for yeast identification. MALDI-TOF mass spectrometry yielded 96.3% and 84.5% accurate species level identifications (spectral scores, ≥1.8) for 138 common and 103 archived strains of yeast. MALDI-TOF mass spectrometry is accurate, rapid (5.1 min of hands-on time/identification), and cost-effective ($0.50/sample) for yeast identification in the clinical laboratory