Polycyclic aromatic hydrocarbons (PAHs) are an important environmental issue and the identification of new biocatalysts for an efficient biodegradation of these compounds is essential for bioremediation. Therefore, fungi strains isolated for the first time from a tropical peat at Santo Amaro das Brotas (Brazil) were studied for fluoranthene biodegradation. Fusarium sp. AC-7, Penicillium sp. AC-1 and Penicillium sp. AC-6 were isolated using fluoranthene as sole carbon source. All strains were tested for biodegradation of 100 mg L−1 fluoranthene during 14 and 28 days. After 28 days of biodegradation, 64 ± 3, 60 ± 4 and 51 ± 2% biodegradation was observed for Penicillium sp. AC-1, Penicillium sp. AC-6 and Fusarium sp. AC-7, respectively. Analysis of the obtained compounds enabled the identification of four metabolites, which were common to the three employed strains: anthrone, anthraquinone, 9-methoxyanthracene and cyclopropa[1]phenanthrene. It is important to note that control experiments were performed. The obtained results clearly demonstrated the efficiency of tropical peat fungi in the transformation of fluoranthene. These findings showed the potential of tropical peats for isolation of fungi and indicated that these strains can be applied for bioremediation processes of areas contaminated with fluoranthene and other PAHs.

New biocatalysts for bioremediation techniques are necessary nowadays. Therefore, a bacterial consortium isolated from Brazilian Savannah was employed for biodegradation of 100 mg L-1 esfenvalerate in liquid culture medium. The bacterial consortium (Lysinibacillus xylanilyticus CBMAI2085, Bacillus cereus CBMAI2067, Lysinibacillus sp. CBMAI2051 and Bacillus sp. CBMAI2052) biodegraded this pyrethroid efficiently. The assays were conducted in triplicate, and after 12 days, 90% of the pesticide was degraded producing 3-phenoxybenzoic acid (35.0 ± 3.1 mg L-1) and 2-(4-chlorophenyl)-3-methylbutanoic acid (34.0 ± 2.8 mg L-1). The bacterial consortium (52 ± 5% biodegradation) was more efficient in the biodegradation than the average of the same strains solely employed (40 ± 7% biodegradation), showing that the use of consortia is an interesting approach. However, the strain Bacillus cereus CBMAI2067 (67 ± 3% biodegradation) was more efficient than the bacterial consortium, showing its potential as source of carboxylesterases and proving that, in this case, the use of a unique efficient strain is more adequate.

In this study, whole cells of marine-derived fungi were used to reduce isatin (1H-indole-2,3-dione) to dioxindole (3-hydroxyindolin-2-one) for 7 days at 32 °C. The screening showed that several strains could reduce isatin and produce the enantioenriched dioxindole. The best conversions were obtained by Cladosporium sp. CBMAI 1237 and Westerdykella sp. CBMAI 1679, however, the best enantiomeric excess was obtained only by Aspergillus sydowii CBMAI 935 (66% ee). In conclusion, marine-derived fungi show potential for asymmetric and chemoselective reduction of isatin (1H-indole-2,3-dione).