Removal of chlorophenolic derivatives by soil isolated ascomycete of Paraconiothyrium variabile and studying the role of its extracellular laccase

• Published in: Journal of hazardous materials 2012-03, Vol.209-210, p.199-203
• Main Authors: Forootanfar, Hamid, Movahednia, Mohammad Mehdi, Yaghmaei, Soheila, Tabatabaei-Sameni, Minoosadat, Rastegar, Hossein, Sadighi, Armin, Faramarzi, Mohammad Ali
• Format: Article
• Language: English
• Subjects: 2,4-dichlorophenol; Ascomycota; Ascomycota - isolation & purification; Ascomycota - metabolism; Biodegradation, Environmental; Chlorophenol; Chlorophenols - isolation & purification; Chlorophenols - metabolism; Culture Media; Fermentation; fungi; guaiacol; Hydrogen-Ion Concentration; Laccase; Laccase - metabolism; monitoring; Paraconiothyrium variabile; pentachlorophenol; Pollutant; pollutants; Removal; soil; Soil Microbiology; toxicity
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2012.01.012

► The ability of newly isolated laccase producing ascomycete, Paraconiothyrium variabile, for removal of chlorophenolic derivatives was investigated. ► The best condition for removal of para-chlorophenol was determined. ► The role of extracellular laccase in this removal was also studied. The ability of Paraconiothyrium variabile, a laccase producing ascomycete recently isolated from soil, was studied to eliminate chlorophenol derivatives in submerged culture medium. Among the tested compounds, ρ-chlorophenol (ρ-CP) and pentachlorophenol (PCP) were found to have minimum and maximum toxic effects, respectively, on the growth of the microorganism and at the same time high and low bioelimination percentages. The fungal strain was able to remove 86% of ρ-CP (with initial concentration of 40mgl−1) and 56% of 2,4-dichlorophenol (2,4-DCP; with same concentration as ρ-CP) after 9 days of incubation while no elimination was observed in the presence of 2,4,6-trichlorophenol (2,4,6-TCP) and PCP. Monitoring of laccase production level in the fermentation broth together with pollutant removal confirmed the key role of this copper-containing oxidase in chlorophenol derivatives elimination. The type of laccase inducer (guaiacol) and its final concentration (250μM) and also initial pH of the fermentation broth (pH=5.5) in the elimination of ρ-CP increased the final removal yield from 86% to 94.3%.