Enhanced esterase activity during the degradation of dibutyl phthalate by Fusarium species in liquid fermentation

Dibutyl phthalate (DBP) is one of the most abundantly produced and used plasticizers and is incorporated into plastic to make it more flexible and malleable. DBP has been found to be an environmental contaminant and reported as an endocrine disruptor. Therefore, it is crucial to develop ecofriendly alternatives to eliminate phthalate pollution. In the present research, the growth of F. culmorum and F. oxysporum in the presence of DBP was studied in liquid fermentation. The esterase activity, specific growth rate, and growth and enzymatic yield parameters were determined in DBP-supplemented media (1,500 or 2,000 mg/L) and in control medium (lacking DBP). These results show that in general, for both Fusarium species, the highest esterase activities, specific growth rates, and yield parameters were observed in media supplemented with DBP. It was observed that 1,500 and 2,000 mg of DBP/L did not inhibit F. culmorum or F. oxysporum growth and that DBP induced esterase production in both fungi. These organisms have much to offer in the mitigation of environmental pollution caused by the endocrine disruptor DBP. This study reports, for the first time, esterase production during the degradation of high concentrations (i.e., 1,500 and 2,000 mg/L) of DBP by F. culmorum F. oxysporum.