Utilization of 4-n-nonylphenol by Metarhizium sp. isolates

Nonylphenol (4-NP) is a xenobiotic classified as an endocrine disrupting compound with an ability to interfere with hormonal systems of numerous organisms including humans. It is widely distributed not only in aquatic but also in terrestrial systems. The aim of this study was to evaluate the ability of cosmopolitan fungus Metarhizium (commonly persistent in soil as a facultative insect pathogen, controlling populations of arthropods in natural environment) to degrade 4-n-nonylphenol. All isolates examined in this work were identified to a species rank based on five, independent genetic markers. Among eight Metarhizium strains; six of them have been identified as M. robertsii, and two others as M. brunneum and M. lepidiotae. All investigated Metarhzium isolates were found to eliminate 4-n-NP with significant efficiency (initial xenobiotic concentration 50 mg L-1). The degradation process was very effective and at 24h of incubation 50-90% of 4-n-NP was eliminated by certain strains, while extended incubation resulted in further utilization of this compound. At the end of the experiments 64-99% of 4-n-NP was removed from the culture medium. Additionally, in all tested cultures three major metabolites were detected: 4-hydroxybenzoic acid; 2-(4-hydroxyphenyl)acetic acid and 4-hydroxyphenylpentanoic acid. The obtained results indicate that Metarhizium sp. possesses an ability to degrade NP and can serve as a potential candidate for further biodegradation studies.