Efficient immobilization of mushroom tyrosinase utilizing whole cells from Agaricus bisporus and its application for degradation of bisphenol A.

A simple and efficient procedure for preparation and immobilization of tyrosinase enzyme was developed utilizing whole cells from the edible mushroom Agaricus bisporus, without the need for enzyme purification. Tyrosinase activity in the cell preparation remained constant during storage at 21 °C for at least six months. The cells were entrapped in chitosan and alginate matrix capsules and characterized with respect to their resulting tyrosinase activity. A modification of the alginate with colloidal silica enhanced the activity due to retention of both cells and tyrosinase from fractured cells, which otherwise leached from matrix capsules. The observed activity was similar to the activity that was obtained with immobilized isolated tyrosinase in the same material. Mushroom cells in water were susceptible to rapid inactivation, whereas the immobilized cells maintained 73% of their initial activity after 30 days of storage in water. Application in repeated batch experiments resulted in almost 100% conversion of endocrine disrupting bisphenol A (BPA) for 11 days, under stirring conditions, and 50-60% conversion after 20 days, without stirring under continuous usage. The results represent the longest yet reported application of immobilized tyrosinase for degradation of BPA in environmental water samples.