Determine the Potency of Caffeine Degradation Microbes and Process Optimization

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Addis Ababa University


Bioremediation being a problem solver for many different environmental and other major hazards, they play an important and cost effective role in the decaffeination process. Form collected environmental sample coffee husk. From CH caffeine can be eliminated. With this experimental work take two spp of microorganism that were bacillus subtilis and rhizobium from Ethiopia bio diversity institute, that can be capability of improving soil fertility. Could grow on the medium supplemented with 2.5g/L caffeine and could effectively degrade 2.5 g/L of caffeine in the liquid media as a sole source of carbon and nitrogen. Morphological and biochemical characteristics were maintained for re-affirmation the organism as bacillus subtilis and rhizobium. The degradation of caffeine capability was authenticated by growth curve. The next task were that those authenticated caffeine degrading bacteria applicable for conserving soil fertility by means of N-fix and p- solubilized potential then propagation and growth of those selective caffeine degrading bacteria was maintained by selective medium with and without supplement of 2.5g/l caffeine then optimized the factors that affecting cell growth with prepared broth with and without supplement of caffeine and determined interaction of each factor from experiment design software 6.0.8) the result would be temp; 35 o c, pH 7.07 incubation time 36hr from those optimal condition obtained maximum cell growth in number was 3.41995E+008 and 5.0707E+008 with and without caffeine respectively for bacillus subtilis and temp 34 o c, pH 6.6 and incubation time 28hrs optimum condition maximum cell growth 3.51146E+008 and 4.09131E+008 was obtained for rhizobium sp. of organism. That viable cell grown microorganism ready for applicable of as liquid bio fertilizer those were easiest way of production, handle, cost effective and keep soil health care method of production.



Coffee husk, caffeine, rhizobium, bacillus, subtilis, tannins, YEM, PIKOVSKAYA medium