Optimum pH for di(2-ethylhexyl) phthalate degradation by Fusarium culmorum in submerged fermentation

Abstract

Di(2-ethylhexyl) phthalate (DEHP) is a plasticizer widely used in the manufacture of plastics, and it is an environmental contaminant. This compound is considered as potential human health risks due to their endocrine-disrupting effects. Due to these concerns, there is a need to search of environmental remediation alternatives. Fusarium culmorum has shown capability to degrade DEHP due its esterase production. Optimization of the pH is crucial in the fermentation process, since the cultivation conditions are essential for a successful enzyme production by the organism. In this work, the specific growth rate, maximum biomass, esterase activity and enzymatic yield parameters were determined for F. culmorum grown at different pH values (5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5 and 9.0) in a medium added with DEHP (1000 mg/L) as sole carbon source in submerged fermentation. It was found that the greatest enzymatic yield parameters were observed at pH values of 5.5 and 6.5, showing that these values were the optimum pH values for DEHP degradation by F. culmorum.