Abstract

MICROBIAL DYNAMICS DURING COMPOSTING OF COFFEE WASTE (HUSK) IN JIMMA, SOUTHWESTERN ETHIOPIA

Seid Mohammed* and Diriba Muleta

Abstract

The current study is about isolation of some dominant microorganisms from compost of coffee wastes within Jimma Agricultural campus. Composting of coffee waste (husk) was conducted with cow dung, poultry manure and bone meal in the ratio of 3:1. Some physicochemical parameters temperature and pH were measured for composts of coffee husk + cow dung (A), coffee husk + poultry manure (B) and coffee husk + bone meal (C). Microbial dynamics were analyzed every five days of turning compost. Different biochemical tests such as KOH-test, motility, catalase, oxidase cytochrome test, oxidation fermentation test, Gram-staining and citrate utilization test were conducted for characterization of the obtained isolates. Data were computed using table and figure. SPSS version 16 was also used for data analyzing. Variations (p<0.05) were observed for both temperature and pH value based on type of composted materials and duration of compost. Changes in a number of microbial dynamics during composting of this coffee husk were observed. Some species of bacteria and fungi with morphological characteristics of Bacillus, Pseudomonas, Serratia, Enterobacter, Azotobacter, Penicillium, Rhizopus, Cladosporium, Aspergillus, Trichosporon, Conidiobolus, Scedosporium, Fusarium, Actinomyces sp., Streptomycete sp and other Actinomycete sp. were presumptively isolated from coffee husk combinations. Some other Cocci, thermophilic bacteria and fungi were also isolated from compost A, B and C on the first 20 days of composting. Generally, these microbes were isolated from compost piles at different temperature and pH value.

Keywords: Compost, microorganism, pH, substrate combination and Temperature.