Tolerância a hidrocarbonetos policíclicos aromáticos (HPAs) por fungos filamentosos isolados de sedimentos contaminados da região Amazônica

Tolerance to Polycyclic Hydrocarbons Aromatic (PAHs) is considered an important characteristic when assessing the bioremediation potential of microorganisms. Given this, the objective of this research was to assay filamentous fungi from the Amazon region, isolated from sediments with differents levels of contamination by PAHs, for tolerance to phenanthrene and pyrene. To achieve this, fungal cultures plugs (5 mm), obtained after 7 days growth, were transferred to petri dishes containing 20% Sabouraud dextrose agar medium, after surface innoculation with phenanthrene and pyrene crystals, separately. Radial mycelial growth was evaluated after 10 days at five different concentration levels for each contaminant and control group, all in triplicate for each treatment. Fungal growth and growth inhibition rates were calculated. The average growth of the colonies in each treatment was compared with one-way ANOVA, followed by a Tukey Test (p < 0,05). All fungi showed tolerant to phenanthrene and pyrene. However, Hypoxylon sp. showed the lowest growth inhibition rate and average growth rates significantly different of the other six tested species. Hypoxylon sp. has been shown to be a promising genetic resource for use in new studies of PAHs degradation. © 2017, Eduem - Editora da Universidade Estadual de Maringa. All rights reserved

Polycyclic aromatic hydrocarbons in superficial sediments of the Negro River in the Amazon region of Brazil

Polycyclic aromatic hydrocarbons (PAHs) were identified and quantified in samples of superficial sediments of the Negro River, in the Amazon region of Brazil, through analyses performed by GC/MS. Total PAH concentration that includes parent and alkylated PAHs ranged from 6.5 to 5348 ng g-1 of dry weight. The Σ16 PAHs prioritized in environmental studies by the U.S. Environmental Protection Agency (USEPA) ranged from 5.6 to 1187 ng g-1. The most contaminated places were those where muddy sediments were found, with the highest concentrations of organic matter, carbon and total nitrogen. The priority PAHs with high molecular weight represented 70% of the total abundance and showed that the main source of contamination of the sediments was pyrogenic. However, petrogenic PAHs coming from oil and derivatives input is also an important contamination source to be considered. ©2015 Sociedade Brasileira de Química

Polyclyclic aromatic hydrocarbons (PAHs) in marine organisms from the Admiralty Bay, Antartic Peninsula

As concentrações de HPAs foram analisadas em invertebrados (Laternula elliptica, Nacella concinna, Yoldia eightsi, Glyptonotus antarcticus, Serolis polita, Euphausia superba, Bovalia gigantea, Sterechinus neumayeri, Odontaster validus e Ophionotus victoriae), peixes (Notothenia rossii), e aves (Pygoscelis Adélia, P. papua, P. antarcticus, Macronectes giganteus, Catharacta sp. e Larus dominicanus) da Baía do Almirantado. As análises de HPAs foram realizadas através de GC/MS. A ocorrência de HPAs nas amostras indicou a biodisponibilidade destes compostos para os organismos da região. As concentrações de HPAs totais para os invertebrados (3,09-174,4 ng g -1 pu) foram maiores que em peixes (0,97-58,9 ng g -1 pu) e menores que em aves (60,1-6861,0 ng g-1 pu), porém apresentaram similaridade entre si. As aves voadoras adultas apresentaram maiores concentrações que os pinguins. Compostos leves e alquilados predominaram em quase todas as amostras, principalmente os alquilnaftalenos. A principal fonte de HPAs para os organismos foi o DFA utilizado na EACF. Espécies predadoras/necrófagas apresentaram HPAs individuais diferentes das espécies suspensívoras/depositívoras. Não ocorreu relação entre o aumento da concentração de HPAs e o aumento do nível trófico dos grupos, e a absorção de HPAs pelas espécies sofreu a influência de fatores como metabolismo, fisiologia, hábito alimentar e teor de lipídio das espécies analisadas.The concentrations of PAHs had been analyzed in invertebrates (Laternula elliptica, Nacella concinna, Yoldia eightsi, Glyptonotus antarcticus, Serolis polita, Euphausia superba, Bovalia gigantea, Sterechinus neumayeri, Odontaster validus and Ophionotus victoriae), fish (Notothenia rossii) and birds (Pygoscelis adélia, P. papua, P. antarcticus, Macronectes giganteus, Catharacta sp. and Larus dominicanus) Admiralty Bay. The analyses of HPAs had been carried through GC/MS. The occurrence of PAHs in the samples indicated the bioavailability of these compounds for the organisms of the region. The concentration of total PAHs for the invertebrates (3,09 to 174,4 ng g-1 pu) were higher than fish (0,97 to 58,9 ng g-1 pu) and lower than in birds (60,1- 6861,0 ng g-1 pu) however, they had presented similarity between themselves. The adult flying birds had presented higher concentrations than penguins. Light and alkylated compounds had predominated in almost all samples, mainly the alkylnaphthalenes. The main source of PAHs for the organism was the DFA used in the EACF. Predators/necrophagous species had presented different individual PAHs from the feeder/deposit species. There was no relation between the increase of concentrations of PAHs and the increase of the trophic level of the groups, and the absorption of PAHs for the species had the influence of factors such as metabolism, physiology, alimentary habits and lipid content of the analyzed species

Biodegradation of the fungicide carbendazim by bacteria from Coriandrum sativum L. rhizosphere

 The biocidal agrochemicals commonly used in agriculture can remain in the soil, affecting the environmental conditions and causing serious risks to health. Knowing that soil microorganisms, especially those from the rhizosphere, can degrade environmental xenobiotics, it was evaluated the potential of bacteria isolated from Coriandrum sativum L. rhizosphere to biodegrade carbendazim (MBC), a fungicide extensively used by agriculturists from rural farming communities in Manaus, Amazonas. Cultures carried out in medium containing carbendazim as a sole carbon source enabled the isolation of 80 bacteria, in the established conditions. Assays to determine degradation potential allowed the selection of the two elite isolates identified as Stenotrophomonas sp. and Ochrobactrum sp. Quantitative assays with each strain individually or in consortium, were carried out using minimal salt medium added with carbendazim (250 µg mL-1) and incubated at 30°C, under agitation (125 rpm) for 21 days. Samples used in the biodegradation test were HPLC analyzed for final fungicide quantitation. The Stenotrophomonas sp. strain was more efficient (68.9%) to degrade carbendazim and showed no toxicity in tests with Artemia salina.

Filamentous Fungi Isolates of Contaminated Sediment in the Amazon Region with the Potential for Benzo(a)pyrene Degradation

Filamentous fungi were isolated from contaminated sediment samples in the Amazon region of Brazil to select species with potential for benzo(a)pyrene (BaP) degradation, a polycyclic aromatic hydrocarbon (PAH) with high molecular weight and known for its mutagenic and carcinogenic properties. The isolates were submitted to biodegradability test using 2.6-dichlorophenol indophenol (DCPIP), gallic acid reaction, and evaluation of BaP influence in the enzymatic (ligninolytic) activity. The selected fungi were submitted to the taxonomic identification and used in biodegradation assays, which were carried out using gas chromatography coupled to mass spectrometry (GC-MS). A qualitative analysis of the presence of BaP metabolites that have recently been reported in literature was also performed by GC-MS. A total of 146 fungal isolates were recovered. Among them, 63.7 % were positive for the redox indicator DCPIP. From these isolates, 22.6 % showed positive responses to the gallic acid reaction. In enzymatic tests, the fungi Megasporoporia sp. S47 and unidentified Sordariales S69 presented highest activities of laccase and manganese peroxidase in the presence of BaP. Additionally, the white-rot fungus Megasporoporia sp. S47 showed better performance in BaP degradation (54 %). Therefore, Megasporoporia sp. S47, obtained from an environment with considerable PAH contamination, was selected as a promising genetic resource for application in new studies related to enzyme production and characterization and BaP degradation optimization. © 2016, Springer International Publishing Switzerland