Browsing by Author "Elias Walelign"

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    Isolation and Identification of Lactic Acid Bacteria from 'Qibe', A Traditionally Prepared Ethiopian Butter
    (Addis Ababa Univensity, 2012-06-01) Elias Walelign; Tesfaye Sisay
    'Qibe' is a traditionally prepared Ethiopian butter made by churning fully soured cow’s milk. In this study,’Qibe’ samples originating from different parts of the country (Gojjam, Sidamo, Jimma, Sheno and Wolega) and sold at Merkato butter market have been be used. The study focused on the isolation and identification of Lactic acid bacteria (LAB) from 'Qibe'. For this purpose, six different butter retail shops were chosen. LAB were isolated based on their Gram stain and catalase test reactions. They were identified to the genus level based on their growth difference at different temperature levels (10°C, 21° C, and 45°C), NaCl concentrations (4%, 6.5%), tolerance to 60°C for thirty minutes and their reaction to citrate utilization as their sole energy source. Accordingly, 56 typical isolates of lactic acid bacteria (LAB) were selected out of the 87 isolates from samples of cow's butter ('Qibe'). They were further classified in to 5 different genera: Pediococcus, Streptococcus, Lactobacillus, Enterococcus and Lactococcus(44.6%, 21.4%, 21.4%, 12.5% and 5.3%, respectively). The highest proportion of Pediococci (48%), Streptococci (41.6%) and Lactococci (50%) were identified from Sidamo , Wolega and Wolega isolates, respectively. An increment in the diversity of the LAB species was also noticed in aged/ripe (three different species of LAB in 1.5 month and 2 months old Gojjam and Wolega samples, respectively, as compared to only one species of LAB identified from a 2weeks old Sheno and Sidamo samples) butter than in fresh ' Qibe' samples. The results showed that Pediococcus, Streptococcus and Lactobacillus were the predominant genera in this traditionally produced butter. However, identification of this isolates to the species level and assessing the technological performance of thus predominant isolates is essential and needs further investigation