Long-Chain Alkylphenols Biodegradation Potential of the Soil <i>Ascomycota</i>

Abstract

A total of 11 strains ascomycetes-destructors of technical nonylphenol (NP) and 4-tert-octylphenol (4-t-OP) were isolated from nonylphenol-contaminated soddy-podzolic loamy soil (Leningrad Region, Russia). Fungal isolates are able to degrade NP and 4-t-OP at a high load (300 mg/L). The most effective Fusarium solani 8F strain has the ability to degrade alkylphenols (AP) both under cometabolic conditions and without additional carbon and energy sources. The decrease in AP is due to the processes of biodegradation and/or biotransformation by the studied strain and, to a small extent, due to sorption by fungal cells. The NP and 4-t-OP half-life under cometabolic conditions is 3.5 and 6.4 hours, respectively, and without additional carbon and energy sources, 9 and 19.7 hours, respectively. The amount of the lipid peroxidation product, malondialdehyde, as well as the reduced glutathione content in the process of NP and 4-t-OP biodegradation under cometabolic conditions increases by 1.7 and 2 times, respectively, compared with the control. The high level of reduced glutathione in F. solani 8F cells may indicate the participation of this metabolite both in the processes of AP biodegradation and in providing strain resistance to oxidative stress. To our knowledge, this is the first report on the degradation of NP and 4-t-OP by ascomycetous fungus F. solani both under cometabolic conditions and without additional carbon and energy sources. The revealed high potential of soil ascomycetes to degrade alkylphenols can be the basis for new environmentally safe bioremediation technologies for the purification of endocrine-disruptors conta-minated soils, natural and waste waters.