Determining the Optimal Conditions for Crude Cellulase Production from Fusarium Oxysporum Isolated from Native Environments

Abstract

Background: Production of cellulase by Fusarium oxysporum has been studied under solid state fermentation technique using crushed of agro-residues: Date cores, Wild reed, Peanut shell, Sunflower scales, Corn cobs, Banana peel and Sawdust as substrate. Objective: Determination of the optimum conditions for the production of crude cellulase enzyme by Fusarium oxysporum using solid-state fermentation technology. Materials and Methods: Isolation of cellulase-producing fungi, Conducting a qualitative and quantitative examination of the cellulase produced by isolated fungi, optimization of SSF parameters for cellulase production include different :solid substrate materials, carbon sources, levels of moisture content, nitrogen sources, incubation temperatures, incubation periods and  inoculumsize, have been studied. Results: Ten isolates of Fusarium spp. were identified, it was found that isolate F4 outperformed the rest of the isolates in the cellulase production, which was diagnosed as Fusarium oxysporum. This isolate was subjected to experiments to determine the optimal conditions for the crude cellulase production. Corn cobs (Cc) gave the maximum CMCase and FPase production with specific activity 19.46U/mg and 9.52U/mg respectively. CMC was gave the highest yield of CMCase and FPase production with specific activity of 21.92U/mg and 10.06U/mg respectively. The best moisture content was 60% for the production of CMCase and FPase with specific activity 22.93U/mg and 10.61U/mg respectively. Ammonium sulphate supported maximum CMCase and FPase production with specific activity 24.88U/mg and 11.96U/mg respectively. It was found that 25°C was the best temperature for the production CMCase and FPase with specific activity of 26.78U/mg and 12.13U/mg respectively. The greatest production of CMCase and FPase was obtained at incubation period 120h with specific activity 30.57U/mg and 12.68U/mg respectively. Maximum specific activity of CMCase and FPase was 33.86U/mg and 12.67U/mg respectively, when using inoculum size with concentration 1x10⁶spore/ ml. Conclusions: The best solid substrate for cellulase production under SSF was crushed corn cobs through fermentation by F. Oxysporum, this substrate is cheap and readily available as well as being a viable alternative for large-scale production of cellulase. Also moisture content, nitrogen source, incubation temperature, incubation periods and inoculum size influenced the ability of fungus to secrete the enzyme.