ABSTRACT Pyrene and benzo[a]pyrene (BaP) are high molecular weight polycyclic aromatic hydrocarbons (PAHs) recalcitrant to microbial attack. Although studies related to the microbial degradation of PAHs have been carried out in the last decades, little is known about degradation of these environmental pollutants by fungi from marine origin. Therefore, this study aimed to select one PAHs degrader among three marine-derived basidiomycete fungi and to study its pyrene detoxification/degradation. Marasmiellus sp. CBMAI 1062 showed higher levels of pyrene and BaP degradation and was subjected to studies related to pyrene degradation optimization using experimental design, acute toxicity, organic carbon removal (TOC), and metabolite evaluation. The experimental design resulted in an efficient pyrene degradation, reducing the experiment time while the PAH concentration applied in the assays was increased. The selected fungus was able to degrade almost 100% of pyrene (0.08 mg mL-1) after 48 h of incubation under saline condition, without generating toxic compounds and with a TOC reduction of 17%. Intermediate metabolites of pyrene degradation were identified, suggesting that the fungus degraded the compound via the cytochrome P450 system and epoxide hydrolases. These results highlight the relevance of marine-derived fungi in the field of PAH bioremediation, adding value to the blue biotechnology.

Neste trabalho foi desenvolvido um método para a determinação de hexaclorobenzeno, lindano, heptaclor, heptaclor epóxido, aldrin, dieldrin, endrin, DDT e DDE em folhas de Mikania laevigata, Maytenus ilicifolia e Cordia verbenacea, empregando a Cromatografia Gasosa acoplada a Espectrometria de Massas (GC-MS). A extração dos pesticidas foi realizada por extração sólido-líquido (SLE), seguida de limpeza por extração em fase sólida (Florisil e silica-gel). A quantificação foi realizada usando o GC-MS no modo SIM. A recuperação média variou de 70 a 124%. A precisão inter-ensaio de uma amostra fortificada com 200 ng g-1 de cada pesticida variou de 1,0 a 7,3%. Os limites de quantificação variaram de 3,0 a 30 ng g-1 e estão abaixo dos limites máximos de resíduos (MLR) estabelecidos para os pesticidas sob estudo. O método foi empregado para analisar amostras de Mikania laevigata, Maytenus ilicifolia e Cordia verbenacea de um campo experimental de Paulínia, SP, Brasil. As amostras apresentaram contaminação com dieldrin acima do MRL estabelecido pela Farmacopéia Européia (50 ng g-1).

A method using Gas Chromatography coupled to Mass Spectrometry (GC-MS) for the determination of hexachlorobenzene, lindane, heptachlor, heptachlor epoxide, aldrin, dieldrin, endrin, 4,4'-DDT and 4,4'-DDE in leaves of Mikania laevigata, Maytenus ilicifolia and Cordia verbenacea was developed. Extraction of the pesticides was carried out by solid-liquid extraction (SLE), followed by clean-up in solid phase mixed cartridge (Florisil and silica-gel). Quantification was performed using GC-MS in the selected ion monitoring mode. Mean recovery rates of 70 to 124% were obtained. The inter-assay precision of a sample fortified with 200 ng g-1 of each pesticide was in the range of 1.0 to 7.3%. The quantitation limits ranged from 3.0 to 30 ng g-1 and were below the Maximum Residue Limit (MRL) for all the pesticides under study. The method was employed to analyze samples of Mikania laevigata, Maytenus ilicifolia and Cordia verbenacea from an experimental field in Paulínia, SP, Brazil. The samples presented contamination with dieldrin above the MRL established by the European Pharmacopoeia (50 ng g-1).