Screening mitosporic fungi for organochlorides degradation

Abstract

Fifty-five isolates of filamentous fungi were studied regarding their ability to decolorize Remazol brilliant blue R dye. The fungi were isolated from soil in the Baixada Santista region, which is contaminated with industrial residues containing a mixture of organochlorine compounds, mainly hexachlorobenzene. The fungi were grown in liquid malt extract medium with 0.02% of dye and shaken at 200 rpm for 14 days at 28 ± 2ºC. Two types of behavior regarding the dye were observed: adsorption and degradation. Eupenicillium baarnense SSP1951 and SSP1952 and Eupenicillium crustaceum SSP1953 presented high RBBR decolorization and were then analyzed regarding their ability to degrade 14 C-hexachlobenzene (4138.31 mg HCB per kg soil) during a 56 days culture at 28 ± 2ºC. Eupenicillium crustaceum SSP1953 was able to reduce n-hexane soluble 14 C-compounds (24.6%) and to form non-extractable 14 C-residues (20.5%). The same behavior was also observed in the two E. baarnense strains (SSP1951 and SSP1952) but the percentages were lower than those obtained for Eupenicillium crustaceum. The main action of Eupenicillium spp on HCB is to transform it into non-extractable 14 C-residues as confirmed by the gas chromatography results.