Isolation and Characterization of Amylase Producing Yeasts and Improvement of Amylase Production

WOS: 000323180100016Objectives: Because most of the yeasts from nature are not harmful as compared to bacteria, interest in yeasts with potential use in biotechnological processes has increased in recent years. Therefore, in this study, we aimed to isolate and characterize amylase producing yeasts and investigate the effects of different parameters on the production of amylase. Methods: Five different sources were used for the isolation of the yeasts. For screening of the amylase production, the isolates were incubated in Amylase Activity Medium at 30 degrees C for 3 days. The amylase activity was determined by dinitrosalicylic acid method. Molecular characterization of the amylase producing yeasts was performed with restriction fragment length polymorphism (RFLP) of the 5.8S and 18S rRNA regions, and sequence analysis of D1/D2 domain of the 26S rRNA region. Results: In total, twenty five yeast isolates were obtained from five different sources. Following the incubation in medium containing starch for the screening of amylase production, it was found that 12 yeast isolates produce amylase, and among the isolates, three of them showed the highest amylase activity. The isolates (19-3, 19-6 and 19-7) having the highest activity were identified as S. fibuligera. The strains showed the highest amylase production at 30 degrees C and pH 5.5. Among additives, sodium chloride, polyethylene glycol, sodium dodecyl sulfate, Triton X-100 and Tween 80 stimulated the production of amylase. Other additives showed negative influence on the production of enzyme. Conclusion: The study revealed that favorable fermentation conditions and the selection of suitable growth parameters played key roles in the production of amylase by S. fibuligera.Scientific Research Unit of Ege UniversityEge University [12-FEN-020]This work was financially supported by the Scientific Research Unit of Ege University (Project Number: 12-FEN-020). We would like to extend our thanks to the Izmir Institute of Technology, Biotechnology and Bioengineering Central Research Laboratories (BIYOMER) for providing laboratory facilities for DNA sequencing studies

Isolation and characterization of yeasts associated with Turkish-style homemade dairy products and their potential as starter cultures

WOS: 000306317600008In this research, 56 yeast strains were isolated from different homemade dairy products in Turkey. Traditional and genotypic methods were used for the characterization of the yeast strains. Debaryomyces hansenii (82%) was the dominant species in all the studied samples and only this species was found in at least one sample from all the studied samples. The other isolates belonged to the species Candida haemulonii, Candida membranifaciens, Candida tropicalis, Candida zeylanoides, Kluyveromyves marxianus, Pichia anomala and Pichia guilliermondii. In the present study, the following properties were studied: lipolytic and proteolytic activities, the ability to grow at different temperatures, different values of pH, different concentrations of salt, and to assimilate and or ferment compounds like citrate, galactose, glucose, lactate, lactose. In conclusion, we found that TEM 16 and TEM 17 strains identifed as D. hansenii in this study have the potential to be used in the production of cheese in Turkey.E.U. The Scientific Research Project (BAP) [2006-Fen-049]This study was supported by E.U. The Scientific Research Project (BAP) 2006-Fen-049

Screening of Lipase Production Among Different Microorganisms

WOS: 00034729860020