Abstract:
Tella” is one of the important Ethiopian traditional beverages, which is prepared from
different ingredients. Ingredients of tella are one of the major important sources of the
isolation of dominant yeast from the local alcoholic beverages. Hence, this study was
conducted to determine the major source of dominant yeast cells by identifying them in the
ingredients of tellasuch as; gesho, bikil, tense, difdif and compared within that of bakery
yeast. The collected samples were processed to isolate yeasts using Yeast extract potato
dextrose agar amended with 0.1 g/L chloramphenicol. Four yeasts were isolated from
theIngredients of tella tella were compared within that of the bakery yeast in terms of
morphological and physiological characteristics such as shape, vegetative reproduction,
ascospore formation, colony count, and Carbon dioxide production by using six sugar in
the Durham tubes. The current result showed all of the yeast isolates were creamy to white
color and ovoid to spherical microscopic shape. Bikil, Difdif, Gesho, and Tinsis yeast
isolates with their sugar fermentative abilities were selected and tested for Carbon dioxide
production. The optimum growth pH and temperature values for all selected yeast isolates
were recorded as 5 and 30℃, respectively, in Yeast extract potato dextrose agar medium.
Among them, Bikil, Gesho, and Tinsis isolate were found to produce more desirable
carbon dioxide in the Durham tube than Difdif. All yeast isolates were identified as
Saccharomyces spp. Based on Cell Count of Selected Yeast Isolates, Bikil contained 6.9 x
106
cfu/ml yet Gesho contained 5.2 x 106
cfu/ml, Tinsis contained 4.5 x 106
cfu/ml, and
Difdif contained 3.6 x 106 cfu/ml but that of the bakery yeast contained 1.12 x 107
cfu/ml.
Thus, bikil was considered the major source of the dominant yeast from ingredients of
tella. As well as in this study, the source and type of the dominant yeast in the beverages at
the consumption stage was identified.Over-all the results of this study showed the yeast
isolates from “tella” showed good fermentative capability as compared to the commercial
S. cerevisiae strains, which are used as controls for this study and Moreover, the finding of
the present study provide a promising source of noble beer yeast isolates with quality
aroma and color
