Statistical Medium Optimization for High Biomass Production of Trichoderma Harzianum: A Potential Biocontrol Agent for Ganodermal Oil Palm Disease

Trichoderma harzianum plays significant role in the future of sustainable agriculture since it can act as biological control agent against broad range of plant pathogens. Basal Stem Rot (BSR) caused by Ganoderma boninense which is a white rot fungus has counted as significant defeat in various regions around the world including South East Asia. In this study, statistical medium optimization in shake flask cultivation applied as an approach to optimize medium composition for high biomass production. Medium optimization was carried out using statistical method of response surface methodology (RSM) based on Box-Behnken design in shake flask culture. The interaction was studied between four different levels of variables that were glucose, peptone, K₂HPO₄, and KH₂PO4. Second order polynomial models were used to correlate the factors to the cell biomass production. The models were found to be significant with the cell biomass production in optimized media reached to approximately 20.0 g L^-1 increment of 80 % while compared in un-optimized media only 4.0 g L^-1. Consequently, the yield coefficient was increased from 0.08 (g g^-1) in un-optimized media to 0.215 (g g^-1) in optimized media. Based on medium statistical design study, results indicated that the optimal medium supporting maximal biomass production had the following composition (g L^-1): glucose, 121.0; peptone, 12.3; KH2PO4, 4.36; and K2HPO4, 8.73. Furthermore,  the cell biomass cultivation in the 16-L stirred-tank bioreactor under un-controlled and controlled pH showing no differences between both cultivation as the maximal biomass produced was  25.0 gL^-1 and 24 gL^-1, respectively.