Biotransformation Studies on Fluoranthene, a Four-ring Polycylic Aromatic Hydrocarbon, by White-rot Fungus Armillaria sp. F022

Abstract

Armillaria sp. strain F022 is capable of degrading a wide range of four-ring aromatic hydrocarbons such as fluoranthene. Production of ligninolytic enzymes during fluoranthene degradation by Armillaria sp. F022 is related to an increase in biomass. Armillaria sp. F022 has been shown to degrade a 10 mg/L solution by 100% within 30 d. Fluoranthene removal decreases with an increase in fluoranthene concentrations. The highest cell weight of Armillaria sp. F022 was showed in the 10 mg/L of fluoranthene culture (≥4,400 mg/L) after 30 d of incubation. Three fluoranthene metabolites were isolated from the culture medium and analyzed by a thin layer chromatography (TLC), UV visible absorption and gas chromatography-mass spectrometry (GC-MS). The oxidation of fluoranthene is initiated by deoxygenation at the C-2,3 and C-7,8 positions. Naphthalene-1,8-dicarboxylic acid, benzene-1,2,3-tricarboxylic acid, and phthalic acid were identified by GC-MS to be present in silylated forms. Two ligninoytic enzymes, namely, laccase and 1,2-dioxygenase, were revealed during the fluoranthene degradation. The results indicate the presence of complicated processes for the regulation of fluoranthene-degrading enzymes.

Isolation of Rhodococcus sp. CMGCZ Capable to Degrade High Concentration of Fluoranthene

“…In 1988, first time the bacterium that could degrade PAHs with four aromatic rings was isolated (Heitkamp and Cerniglia 1988). Fluoranthene (Fla), a compound that consists four fused-aromatic rings in its molecular structure, has cytotoxic, weakly mutagenic, and potentially carcinogenic effects (Mishra et al 2014;Hadibarata and Kristanti 2015). Degradation of Fla as a sole carbon and energy source, by pure bacterial strains, was first reported in 1990 (Mueller et al 1990;Weißenfels et al 1990), and since then, several other reports have described bacterial metabolism of Fla including Sphingomonas (Herwijnen et al 2003), Mycobacterium (Sepic et al 1998), and Rhodococcus (Walter et al 1991); yet, catabolic pathway of Fla by aerobic bacteria has been proposed (Peng et al 2008).…”