Browsing by Author "Assefa, Esayas"

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    Antimicrobial Activity of Lactic Acid Bacteria Isolated From ‘Ergo’, Ethiopian Traditional Fermented Milk, on Some Foodborne Pathogens
    (Addis Ababa University, 2006-11-04) Assefa, Esayas; Beyene, Fekadu
    “Ergo” is a traditional Ethiopian fermented milk produced by spontaneous fermentation using traditional utensils under non-hygienic environment. To produce microbiologically safe and chemically defined product; study on the production, processing, utilization and handling of ‘Ergo’ under different agro-ecological zones as well as the isolation and characterization of potential lactic acid bacteria strains with the potential production of inhibitory factor should be the first essential step. In this study ninety-smallholder farmers from the three districts (Lumme, Fentale, Adami Tulu), thirty from each district, who produced and processed milk were purposeively selected and individually interviewed using a semi-structured questionnaire to asses the production, processing, utilization and handling of traditional fermented milk, “Ergo”. Milk fermentation takes relatively longer period (3.57 + 1.04 days) in Lumme district than the two districts Fentale and Adami Tulu (1.03+ 0.183). All households (100%) in Fentale consume un-boiled milk; rather they utilize it in its fermented or raw state, where as only 40% and 46.6% of households in Lumme and Adami Tulu areas, respectively, used fermented milk for consumption. Even though milk is fermented and consumed in all these areas a very limited hygienic care is practiced, 93.4% of the households do not heed for the sanitary aspect of the milk and milk products. To evaluate the antimicrobial activity of the lactic acid bacteria (LAB), 112 strains of LAB, belonging to Lactococcus, Lactobacillus, Entorococcus, Streptococcus, Leuconostoc and Pediococcus were isolated from Ethiopian traditional fermented milk, “Ergo”. Moreover the culture filtrates of all the isolates were examined for antimicrobial activity on some food born pathogens Salmonella thyphi, Shigella flexineri , Staphylococcus aures (ATCC-25923) and Escherchia coli (ATCC-25922) using disc diffusion assay method. Inhibition diameters obtained with the inhibitory substance of 2mm and above inhibition zone over the control were considered as positive. Twelve strains of lactic acid bacteria that produced the greatest antimicrobial substance were selected. These strains were identified as species of Lactobacillus acidophilus(2) , Lactobacillus plantarum(2), Lactococcus lactic spp crimoris(2) , Lactococcus lactic spp lactic(3), Leuconostoc lactic (1) , Pediococcus pentosaceus(1) and Pediococcus sp.(1). All the inhibitory substance-producing strains were tested for their temperature and pH stability. The antimicrobial activity of the culture filtrate of isolated strains were completely inactivated when treated at 121oC for 15 minutes, where as at 30, 60 and 80oC there were no Significant (P>0.05) difference in diameter of inhibition compared to untreated (control). The entire culture filtrate were stable with in a wide range of pH (2-10) and no significant (P>0.05) difference was observed between the treated filtrate and the untreated (control). However treating the culture filtrate at pH 12 has significantly (P<0.05) decreased the inhibition diameter.
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    The Practices and Challenges of Occupational Safety and Health in Meta Abo Brewery Sc. Co
    (Addis Ababa University, 2018-10-13) Assefa, Esayas; Chane, Abraraw (PhD)
    Occupational accidents and diseases not only entail an appalling human toll, but also account for a significant economic burden on national economies and on enterprises. The general objective of the study was to investigate the practice and challenges of OSH in Meta Abo Brewery share Company. This study applied descriptive research study and used quantitative and qualitative research methods. Primary data was collected using a questionnaire from 98 randomly selected workers from production departments. Though the company had an international based OSH policy and procedure, the study revealed that workers and supervisors in these areas had low commitment to obey the policy: lack of awareness, carelessness or ignorance of safety requirements, Shortage of PPEs, PPE are not comfortable, no strong follow-up and enforcement non-enforcement and lack of motivation. Most of occupational injuries reported during the last 2 years and the overall prevalence during the last 2 years was reported 1-2 times. Hand finger was reported as the highest frequency of occupational injuries and Toe, Eye and Ear were stated as less frequently injuries. The major challenges is lack of awareness among workers and employers about work site safety and health and lack of Workers positive response to wear personal protective equipment (PPEs) in the organization and lack of government audits and/or inspections preferred were considered as a least challenge. Meta Abo should improve safety and health at work through a Decent Work Agenda – it helps to better address occupational safety and health as a vital component of decent work. The company should promote a preventive safety and health culture and progressively achieving a safe and healthy working environment.