Isolation and genotypic characterization of different yeast strains from Nepalese mixed culture (Murcha)
Master thesis
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http://hdl.handle.net/11250/2482475Utgivelsesdato
2017Metadata
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Sammendrag
14 different yeast strains were isolated from the Nepalese yeast cakes (murcha) of six different places varying in geographical condition. The isolation was entirely random based on the morphologies of the colonies, were genotypically characterized using the ITS and LSU region. The fermentation was carried out with modified synthetic must and concentrations of sugars, acid and ethanol was analyzed using HPLC and composition of volatiles were determined using headspace GC-MS. A genetic analysis was made using the internal transcribed spacer (ITS) sequencing to identify the species and establish genetic relationships between the strains. The isolated strains were classified as Vanderwaltozyma, Wickerhamomyces and Saccharomyces after LSU sequencing. Candida inconspicua from Baglung showed lesser gravity fall during fermentation. Maximum utilization of sugars was shown by Saccharomyces while strains of Saccharomycopsis utilized less sugars. Thus, establishing themselves with high and low ethanol producers respectively. The production of ester compounds is found to be very less except for ethyl acetate. Ethyl acetate production was observed very high in most of the strains.