Identification of Dominant Lactic Acid Bacteria and Yeast Species from Teff Injera Dough Fermentation

Traditional fermentation is carried out initially by natural microorganisms present in the substrate. This usually leads to a long fermentation time and occasional failure of the fermentation, and creates inconsistencies in the product quality. Teff injera is one of the widely used Ethiopian fermented foods that suffer from such a problem. Therefore, the aim of this study was the identification of the dominant species of lactic acid bacteria (LAB) and yeast for the optimization of the traditional fermentation process of teff injera dough fermentation. The dominant LAB and yeast species were identified by using morphological, physiological, and biochemical characterization. The growth kinetics of both LAB and yeast in fermented teff dough was increased significantly (p < 0.05) from 8.91 to 9.97 log cfu/g and 5.98 to 7.62 log cfu/g. In this study, five LAB and three yeast dominant strains were identified. The LAB strains were identified as Lactobacillus fermentum (26.7%), Lactobacillus brevis (20%), Lactobacillus plantarum (13.3%), Bacillus subtilis (20%), and Enterococcus casseliflavus (20%), and the yeast species included Saccharomyces cerevisiae (40%), Candida krusei (40%), and Pichia kudriavzevii (20%). Lactobacillus plantarum, Lactobacillus fermentum, Lactobacillus brevis, Bacillus subtilis, Enterococcus casseliflavus, Saccharomyces cerevisiae, Candida krusei, and Pichia kudriavzevii were found to be the most dominant LAB and yeast species and could be detected in fermented teff dough samples from the beginning (24 h) to the later (96 h) fermentation times. In the current study, the fermentation time of teff dough with single starter culture was improved by 75% compared with the conventional fermentation time, which is reduced from 96 to 24 h of fermentation time. Hence, further study will require the molecular characterization of the identified LAB and yeast isolates by using 16s rRNA to confirm the isolates as LAB and yeast.