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

Abstract

Filamentous fungi were isolated from contaminated sediment samples in the Amazon region of Brazil t o 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.

Community response of soil microorganisms to combined contamination of polycyclic aromatic hydrocarbons and potentially toxic elements in a typical coking plant

“…Alternatively, the fungal communities are more responsive and sensitive to environmental changes compared to bacteria. On one hand, it has been shown that fungi can use PAHs as a carbon source for growth and reproduction, thus increasing their species richness ( Souza et al, 2016 ). However, the lower positive impact from PAHs may turn into a negative impact if PAHs concentrations exceed a certain turning point ( Tsui et al, 1998 ), which is confirmed by the negative correlation between PAHs and most fungi (genera) in the present study.…”

Mycoremediation in Soil

“…Filamentous fungi show some peculiar characteristics that make them more advisable in soil bioremediation than yeasts and bacteria [14,15]. The most important are the type of growth (i.e.…”

Isolamento e seleção de fungos tolerantes ao herbicida Glyphosate

“…Dentre os estudos qualitativos, destacam-se a análise da formação do halo de degradação em meios de cultura contendo ácido gálico e guaiacol, além da capacidade de descoloração do corante têxtil Remazol Brilhante Blue R (RBBR), entre outros (Rodríguez, 2014;Lee et al, 2014). Quanto aos testes quantitativos, a literatura tem demonstrado a realização de estudos sobre a atividade de enzimas do complexo fenoloxidases, tais como lacase e certas peroxidases (Barbosa, 2010;Colla, 2008;Lee et al, 2014), testes in vitro da tolerância aos contaminantes de interesse, bem como de biodegradação, análise de metabólitos e capacidade de mineralização (Argumedo-Delira et al, 2012;Souza et al, 2016;Souza et al, 2017).…”

“…Neste trabalho, obteve-se 60% de resposta positiva, reduzindo o número de isolados para prosseguimento dos estudos de seleção de fungos promissores. Resultados similares são relatados na literatura, tais como os encontrados emLee et al (2014),Santana et al (2016),Souza et al (2016) eLee et al (2020). Todos esses trabalhos indicam a importância desse método para triagem inicial de fungos com potencial em biorremediação.…”