Abstract:
Cellulases are the type of enzymes which catalyze the hydrolysis of cellulose and related oligosaccharide derivatives, is considered a potential tool for industrial saccharification of cellulosic biomass. The production of bio-based products and bioenergy from less costly renewable lignocellulosic materials would bring benefits to the local economy, environment, and national energy security. The processed enset (kocho and bulla) are rich in carbohydrates, and fiber and some minerals. Cellulase production is an important strategy for the development of sustainable processes of industrial based cellulase enzyme for some industries such as food, textile, animal feed, detergent etc. Therefore, the present study was undertaken to investigate cellulase production by fungal isolates from traditional fermented enset kocho. The study involved kocho sample collection from fermented enset kocho. The screening for cellulolytic fungal culture was conducted based on zone of inhibition followed by morphological identification of fungal species. The cellulase activity test was conducted for fungal colonies with good cellulolytic activity.Thereafter; the optimization of parameters(carbon and nitrogen source,incubation time and pH) for cellulase activity was conducted. The result indicated that the maximum enzyme activity index (1.85) was recorded for Aspergillus sp2, followed by Penicillium sp (1.81), Aspergillus sp3 (1.80) and Fusarium sp (1.72). The optimum cellulase activity for all isolates including Aspergillus sp2, Penicillium sp and Fusarium sp were between 12h to 48h incubation time with maximum cellulase activity at 24h. The maximum celluase activity for Aspergillus sp2 was between pH 4 to 5 indicating that the optimum pH for cellulase activity of Aspergillus sp2 was in acidic medium ( pH 4.5). The highest celluase activity for Penicillium and Fusarium spp was found between pH 5 to 6 indicating that the optimim pH for cellulase activities of both Penicillium and Fusarium spp were in a weekly acidic medium about pH 5.5. Aspergillus sp2 presented the highest cellulase activity (83.61 U/min) with maltose and Penicillium sp isolate has recorded the maximum cellulase activity (56.60 U/min) with lactose. Penicillium sp presented the highest cellulase activity (238.28 U/min) with peptone. It can be concluded that Aspergillus sp2 can be recommended for celluase production at pH 4 to 5 whilst Penicillium sp can be recommended x as efficient cellulase producing isolate at pH 5.5 to 6. Maltose and lactose can be recommended as carbon source; peptone and yeast extract can be used as nitrogen source culture media for cellulase production.
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