Abstract

Coffee waste represents the most abundant waste in Ethiopia, this study aims to isolate, identify and characterize yeast from coffee waste in order to utilize in the biotechnological process. 25 merged coffee waste samples were collected from Sidama and Gedio zone. Yeast strain was cultured on yeast peptone dextrose and Biolog universal yeast agar media. Pure yeast cells were suspended in sterile water at 49+ turbidity, 100 µ L and transferred into 96 wells of the biolog yeast micro Plate and incubated at 26°C for 24 to 72 h and read by the Micro Station Reader at a single wavelength of 590 nm, results were recorded and processed for identification by micro log3 software ver. 4.20.05. Biolog microstation  acceptable  result  ≥ 75% Probability and  ≥ 0.5 similarity index value identified 5 yeast species, Hanseiaspora valbyensis, (100%PROB,0.707SIM,), Hyphopichia burtonii A (98%PROB,0.060SIM), Rhodotorula hylophila (98%PROB, 0.060SIM), Rhodotrula aurantiaca A (100% PROB, 0.505SIM) and Pichia amenthionina var. menthionina, (PROB 96% SIM,0.714). There was no report on yeasts associated with coffee waste in Ethiopia for utilization in biotechnological process. Therefore characterization of yeasts is very important for industrial and environmental application.

Key words: Biolog, coffee, fermentation, micro station, Omni log, tetrazolium.