Optimizing of Trichoderma viride Cultivation in Submerged State Fermentation

Abstract

Problems statement: A study in Malaysia had shown a strain of Trichoderma viride was isolated from the soil. Questions were raised whether Trichoderma viride submerged state fermentation affected by parameters and which of them is effective? Approach: To investigate the effects of the submerged state fermentation parameters; concentrations of carbon g L^-1; (10, 45 and 80), glucose, nitrogen g L^-1; (0.10, 0.35 and 0.60) ammonium sulfate, temperature; (20, 30 and 40), PH; (4.0, 6.0 and 8.0) rpm. Experiments were performed in triplicate and the results were statistically analyzed using computer software Response Surface Methodology (RSM) using a Box-Behnken design was applied to batch cultures of T. viride, for identifying the effects of process variables (carbon sources, nitrogen sources, temperature, RPM and PH). The fermentation was carried out in shake flasks using a complex medium fungal biomass the mycelium was filtered through filter paper (Whatman No. 40). It was washed first with distilled water tow times. The washed mycelium was dried at 105±1°C to constant mass. It was placed in the desiccators and then the mass was determined. Results: The fermentation pattern was studied to investigate the effects of the submerged state fermentation parameters; concentrations of carbon g L^-1; (10, 45 and 80) glucose, nitrogen g L^-1; (0.10, 0.35 and 0.60) ammonium sulfate, temperature; (20, 30 and 40), PH; (4.0, 6.0 and 8.0) rpm; for Trichoderma biomass production for biotechnological uses (biocontrol agent). Optimum parameters and maximum biomass production were studied. The maximum biomass production of 13.6 g mL^-1 mycelium was noted after 5 days. Although maximum fungal biomass presented maximum growth rate that observed between the 3rd and 4th days of fermentation. At 3rd day 13.2 g L^-1 fungal dry mass was present, after that there was a slight decrease in the mycelial dry mass. A Box-Behnken experimental design was used to investigate the effects of five factors; concentrations of carbon g L^-1; (10, 45 and 80) glucose, nitrogen g L^-1; (0.10, 0.35 and 0.60) ammonium sulfate, temperature; (20, 30 and 40), PH; (4.0, 6.0 and 8.0), rpm; (100, 175 and 250) on the concentrations of biomass produced in batch cultures of Trichoderma viride. Optimal medium for maximizing the production of biomass in batch cultures of T. viride should contain 45 g L^-1 C, 0.35 g L^-1 N, 30 Temp, 175 rpm and Ph 6 for 5 days fermentation. Optimization of Trichoderma cultivation in submerged state fermentation to produce the optimum biomass as stage of biocontrol agent and biofertilizer production which made the production line more significant. Conclusion: Based on a statistically designed search, results indicated that an optimal medium for maximizing the production of biomass in batch cultures of T. viride should contain 45 g L^-1 C, 0.35 g L^-1 N, 30 Temp, 175 rpm and Ph 6. This composition can yield the optimum biomass 5 days of culture. The identified optimal medium is rich in carbon but provided a limiting level of nitrogen.