ISOLATING TEFF (Eragrostis tef (Zucc.) Trotter) FERMENTING MICROORGANISMS AND EVALUATING THEIR POTENTIAL UNDER VARIUOS OPERATING CONDITIONS

Abstract

Teff (Eragrostis tef) is Ethiopia‘s treasured cereal crop, valued for its nutritional quality and central role in making injera. Despite its cultural importance, the microbial processes underlying its fermentation are not well understood. This study investigates the isolation and characterization of fermenting microbes from teff dough and assesses their adaptive performance under different operational conditions. Data were collected through a combination of household surveys and laboratory sampling. Thirty selected households that regularly prepare injera from teff participated in structured questionnaires. Samples of ersho and teff dough fermented for 1–3 days were analyzed for microbial and physicochemical properties. Microorganisms were isolated using selective media: MRS (lactic acid bacteria), PDA (yeasts and molds), PCA (aerobic mesophiles), and VRBG (enterobacteria). Initial screening was conducted at pH 4.0, with further testing across diverse pH levels, salt concentrations, temperatures, and carbohydrate sources. Promising isolates were subjected to morphological and biochemical analysis. A total of 28 isolates were obtained, including 11 lactic acid bacteria (LAB), 9 yeasts and molds, and 8 aerobic mesophiles. Microbial counts increased across the fermentation period, while enterobacteria and Clostridium were absent. Nutritional changes included modest rises in protein content and reductions in ash, fat, and fiber. Notably, selected LAB isolates yielded superior sensory qualities compared to traditional fermentation. Overall, the results highlight the potential of targeted microbial selection to enhance the quality and consistency of fermented teff products, offering a pathway to innovation in traditional Ethiopian food systems.