Natália Alvarenga

Biodegradation of methyl parathion by whole cells of marine-derived fungi Aspergillus sydowii and Penicillium decaturense.

Seven marine fungi strains (Aspergillus sydowii CBMAI 934, A. sydowii CBMAI 935, A. sydowii CBMAI 1241, Penicillium decaturense CBMAI 1234, Penicillium raistrickii CBMAI 931, P. raistrickii CBMAI 1235, and Trichoderma sp. CBMAI 932) were screened by their growth in the presence of methyl parathion (MP) in a solid culture medium. The strains with best growth were A. sydowii CBMAI 935 and P. decaturense CBMAI 1234. Biodegradation reactions were performed in 10, 20 and 30d in a malt extract liquid medium containing commercial MP and whole cells of A. sydowii CBMAI 935 and P. decaturense CBMAI 1234. In 20d, A. sydowii CBMAI 935 was able to degrade all pesticide, whereas P. decaturense CBMAI 1234 promoted a complete degradation in 30d. A. sydowii CBMAI 935 and P. decaturense CBMAI 1234 could degrade the product of the MP enzymatic hydrolysis, p-nitrophenol, on average of 51 and 40% respectively. Both strains used MP as a sole source of carbon and provided satisfactory results. Metabolites detected in the medium showed that the presumable reaction pathway occurred through the activation of MP to its more toxic form, methyl paraoxon, which was further degraded to p-nitrophenol.

Biocatalysis and biotransformation in Brazil: An overview.

This review presents the recent research in biocatalysis and biotransformation in Brazil. Several substrates were biotransformed by fungi, bacteria and plants. Biocatalytic deracemization of secondary alcohols, oxidation of sulfides, sp(3) CH hydroxylation and epoxidation of alkenes were described. Chemo-enzymatic resolution of racemic alcohols and amines were carried out with lipases using several substrates containing heteroatoms such as silicon, boron, selenium and tellurium. Biotransformation of nitriles by marine fungi, hydrolysis of epoxides by microorganisms of Brazilian origin and biooxidation of natural products were described. Enzymatic reactions under microwave irradiation, continuous flow, and enzymatic assays using fluorescent probes were reported.

Growth Assessment of Marine-Derived Fungi in the Presence ofEsfenvalerate and its Main Metabolites

The growth and biodegradation potential of marine-derived fungi were evaluated by measuring the radial growth of colonies. It was observed that Penicillium raistrickii CBMAI 931, Aspergillus sydowii CBMAI 935, Cladosporium sp. CBMAI 1237, Microsphaeropsis sp. Dr(A)6, Acremonium sp. Dr(F)1, Westerdykella sp. Dr(M2)4 and Cladosporium sp. Dr(M2)2 were able to grow and develop in the presence of the pyrethroid insecticide esfenvalerate (S,Sfenvalerate) and its main metabolites (3-phenoxybenzaldehyde, 3-phenoxybenzoic acid, 3-phenoxybenzyl alcohol and 2-(4-chlorophenyl)-3-methylbutyric acid), showing the possibility of esfenvalerate biodegradation by these strains. The presence of technical grade esfenvalerate and its metabolites caused growth inhibition, while fungal development was not affected by the presence of the commercial insecticide SUMIDAN 150 SC in the culture medium. This fact might show that the biodegradation of the esfenvalerate in the commercial insecticide is slower than that of the technical grade active ingredient, since slower biodegradation of esfenvalerate would reduce the concentration of phenolic compounds and thus the growth inhibition. Future studies will focus on the quantitative biodegradation analysis of technical grade esfenvalerate and active ingredient in the commercial insecticide.

Biodegradation of Chlorpyrifos by Whole Cells of Marine-Derived Fungi Aspergillus sydowii and Trichoderma sp

This paper describes the screening of the growth of seven marine-derived fungi strains in the presence of chlorpyrifos in solid medium. The strains that showed best growth were A. sydowii CBMAI 935 and Trichoderma sp. CBMAI 932. Biodegradation reactions were performed in 10, 20 and 30 d in liquid medium containing commercial chlorpyrifos and mycelia from the selected strains. In 30 d, A. sydowii CBMAI 935 and Trichoderma sp. CBMAI 932 were able to degrade on average 63% and 72% of chlorpyrifos, respectively, and reduce the concentration of 3,5,6-trichloro-2-pyridinol, the metabolite formed by the enzymatic hydrolysis of chlorpyrifos. In 30 d, A. sydowii CBMAI 935 and Trichoderma sp. CBMAI 932 could use chlorpyrifos as sole source of carbon with low biodegradation percentages, 24% and 5%, respectively. Spontaneous hydrolysis was evaluated in malt medium, with the complete disappearance of chlorpyrifos. In distilled water, 61% of chlorpyrifos was hydrolyzed in 30 d.

Enantioselective separation of (±)-β-hydroxy-1,2,3-triazoles by supercritical fluid chromatography and high-performance liquid chromatography

This paper reports the enantioseparation of β-hydroxy-1,2,3-triazole derivatives, which present a broad range of biological properties, by supercritical fluid chromatography (SFC) and high-performance liquid chromatography techniques (HPLC). Polysaccharide-based chiral columns (cellulose and amylose) were used to evaluate the separation in SFC and HPLC. Time of analyses, consumption of solvent, and parameter optimization were reduced using SFC technique. The columns based on cellulose chiral stationary phase using 2-propanol and ethanol as modifiers showed the best results for the enantioresolution of the (±)-β-hydroxy-1,2,3-triazoles by SFC analyses. These techniques were applied to evaluate the selectivity of biocatalytic reduction of β-keto-1,2,3-triazoles by marine-derived fungus Penicillium citrinum CBMAI 1186 to obtain the (±)-β-hydroxy-1,2,3-triazoles.

Enantioselective biodegradation of the pyrethroid (±)-lambda-cyhalothrin by marine-derived fungi

The contamination of agricultural lands by pesticides is a serious environmental issue. Consequently, the development of bioremediation methods for different active ingredients, such as pyrethroids, is essential. In this study, the enantioselective biodegradation of (±)-lambda-cyhalothrin ((±)-LC) by marine-derived fungi was studied. Experiments were performed with different fungi strains (Aspergillus sp. CBMAI 1829, Acremonium sp. CBMAI 1676, Microsphaeropsis sp. CBMAI 1675 and Westerdykella sp. CBMAI 1679) in 3% malt liquid medium with 100 mg L-1 of (±)-LC. All strains biodegraded this insecticide and the residual concentrations of (±)-LC (79.2-55.2 mg L-1, i.e., 20.8-44.8% biodegradation), their enantiomeric excesses (2-42% ee) and the 3-phenoxybenzoic acid (PBAc) concentrations (0.0-4.1 mg L-1) were determined. In experiments for 28 days of biodegradation in the absence and presence of artificial seawater (ASW) with the most efficient strain Aspergillus sp. CBMAI 1829, increasing concentrations of PBAc with (0.0-4.8 mg L-1) and without ASW (0.0-15.3 mg L-1) were observed. In addition, a partial biodegradation pathway was proposed. All the evaluated strains biodegraded preferentially the (1R,3R,αS)-gamma-cyhalothrin enantiomer. Therefore, marine-derived fungi enantioselectively biodegraded (±)-LC and can be applied in future studies for bioremediation of contaminated areas. This enantioselective biodegradation indicates that the employment of the most active enantiomer GC as insecticide not only enable the use of a lower amount of pesticide, but also a more easily biodegradable product, reducing the possibility of environmental contamination.

Biodegradation of anthracene and several PAHs by the marine-derived fungus Cladosporium sp. CBMAI 1237

The biodegradation of polycyclic aromatic hydrocarbons (PAHs) by marine-derived fungi was reported in this work. Marine-derived fungi (Trichoderma harzianum CBMAI 1677, Cladosporium sp. CBMAI 1237, Aspergillus sydowii CBMAI 935, Penicillium citrinum CBMAI 1186 and Mucor racemosus CBMAI 847) biodegraded anthracene (14days, 130rpm, 50mgmL-1 initial concentration in malt 2% medium). Cladosporium sp. CBMAI 1237 was the most efficient strain and biodegraded more anthracene in the presence (42% biodegradation) than in the absence (26%) of artificial seawater, suggesting that the biodegradation of PAHs may be faster in seawater than in non-saline environment. After 21days, Cladosporium sp. CBMAI 1237 biodegraded anthracene (71% biodegradation), anthrone (100%), anthraquinone (32%), acenaphthene (78%), fluorene (70%), phenanthrene (47%), fluoranthene (52%), pyrene (62%) and nitropyrene (64%). Previous undocumented metabolites were identified and, anthraquinone was a common product of different PAHs biodegradation. The marine-derived fungus Cladosporium sp. CBMAI 1237 showed potential for bioremediation of PAHs.

Stereoselective reduction of 2-azido-1-phenylethanone derivatives by whole cells of marine-derived fungi applied to synthesis of enantioenriched β-hydroxy-1,2,3-triazoles

Abstract Several marine-derived fungi were evaluated by the bioreduction of 2-azido-1-phenylethanone 1, and the strains A. sydowii CBMAI 935 and M. racemosus CBMAI 847 were selected for the reduction of 2-azido-1-phenylethanone derivatives 2–4. Whole cells of A. sydowii CBMAI 935 promoted the reduction of 2-azido-1-phenylethanones 1–4 with high selectivities to yield the (S)-2-azido-1-phenylethanols 1a–4a. Bioreduction of compounds 1–4 by M. racemosus CBMAI 847 led to (R)-2-azido-1-phenylethanols for 1, 2 and 4 and (S)-2-azido-1-phenylethanol 3. Enantiomerically enriched 2-azido-1-phenylethanols 1a–4a and phenylacetylene 5 were applied in the synthesis of β-hydroxy-1,2,3-triazoles using CuSO4 and sodium ascorbate leading to regioselective formation of enantioenriched 1,4-disubstituted 1,2,3-triazole compounds 1b–4b.

Biodegradation of Organophosphate and Pyrethroid Pesticides by Microorganims

Major methods for the biodegradation of organophosphate and pyrethroid pesticides are reviewed in this chapter. Although these methods are very promising, it is not easy to avoid fully the release of metabolites into the environment. Therefore, serious problems of soil, water and even foods contamination still exist. Despite the great benefits of pesticides to agricultural productivity, they also cause serious problems of contamination and increasingly need studies, especially in the search of compounds that are less harmful to the environment. Knowledge of the biodegradation route of pesticides and the development of new techniques that allow the improvement of these degradation pathways are essential, therefore, this chapter presents studies about the biodegradation of organophosphate and pyrethroid pesticides by biological processes, focussing on the development of new enzymatic methods, especially those using bacteria and fungi. Other methods of biological degradation of organophosphate and pyrethroid pesticides are also described.