BIOTRANSFORMATION OF HYDROQUINONE BY HAIRY ROOTS OF BRUGMANSIA-CANDIDA AND EFFECT OF SUGARS AND FREE-RADICAL SCAVENGERS

Hairy roots of Brugmansia candida were used to bioconvert hydroquinone into arbutin. The highest bioconversion, with the lowest damage to th e cells, was attained when concentrations of 20-40 mg/L hydroquinone w ere used. Sugars (sucrose, glucose, mannitol, and sorbitol) at concent rations of 30-120 g/L enhanced bioconversion, and, of these, sucrose w as the most effective. Two different free-radical scavengers were also tested: sodium benzoate and gallic acid. The first one diminished bio transformation efficiency; gallic acid did not affect biotransformatio n at all. Preliminary permeabilization treatments tested failed to lib erate arbutin into the medium, and provoked a total loss in cell viabi lity.