Biodegradation of Phthalic Acid Esters by the White Rot Fungus <i>Peniophora lycii</i>

Abstract

Abstract—The ability of the white rot fungus Peniophora lycii to degrade such phthalic acid esters (PAEs) as diethyl phthalate (DEP), dibutyl phthalate (DBP), di(2-ethylhexyl) phthalate (DEHP), diisobutyl phthalate (DiBP), and n-butylbenzyl phthalate (BBP) was studied. It was shown that DEHP was most efficiently biodegraded by the fungus (over 98% on day 6 of cultivation). The residual content of DBP and DiBP in the culture liquid of the fungus at the end of cultivation (10 days) was ~17–18%. BBP turned out to be the most difficult-to-degrade compound: its residual content on day 10 of P. lycii cultivation was ~40%. DEP was resistant to fungal biodegradation, and exhibited a toxic effect at 1.5 g/L: the rate of radial growth of the fungus on agar decreased threefold compared to the control, and the amount of fungal biomass during liquid-phase deep cultivation decreased by about 1.5 times. During the cultivation of P. lycii on media with PAEs, an increase in esterase activity by about 2 times and a significant decrease (by 2–4 times) in oxidase activity was shown compared to the control medium without phthalates.