Factors affecting polycyclic aromatic hydrocarbon biodegradation by Aspergillus flavus

Abstract

This study investigated the ability of fungi isolated from highly contaminated soil to biodegrade polycyclic aromatic hydrocarbon (PAH) compounds, as well as the effect of several parameters on the biodegradation ability of these fungi. The isolated fungi were identified using ITS rDNA sequencing and tested using 2,6‐dichlorophinolendophenol to determine their preliminary ability to degrade crude oil. The top‐performing fungi, Aspergillus flavus and Aspergillus fumigatus, were selected to test their ability to biodegrade PAH compounds as single isolates. After 15 days of incubation, A. flavus degraded 82.7% of the total PAH compounds, with the complete degradation of six compounds, whereas A. fumigatus degraded 68.9% of the total PAHs, with four aromatic compounds completely degraded. We also tested whether different temperatures, pH, and nitrogen sources influenced the growth of A. flavus and the degradation rate. The degradation process was optimal at a temperature of 30°C, pH of 5.5, and with nitrogen in the form of yeast extract. Finally, the ability of the fungal candidate, A. flavus, to degrade PAH compounds under these optimum conditions was studied. The results showed that 95.87% of the total PAHs, including 11 aromatic compounds, were completely degraded after 15 days of incubation. This suggests that A. flavus is a potential microorganism for the degradation of PAH compounds in aqueous cultures.

Distinct response of total and active fungal communities and functions to seasonal changes in a semi‐enclosed bay with mariculture (Dongshan Bay, Southern China)

“…Comparing our findings with more recent studies and additional ecological data provided evidence for the ubiquitous dominance of Ascomycota and Basidiomycota in coastal habitats (Wang et al 2014), suggesting that members of these two phyla may play a major role in organic matter cycling (Wang et al 2019). Some fungal genera reported in the present study, such as Aspergillus (Gofar 2013;Al-Dossary et al 2020;Obi et al 2020), Candida (Chrzanowski et al 2005;Kaczorek et al 2008), Penicillium (Al-Dossary et al 2020Obi et al 2020), Pichia, and Yarrowia (Kutty and Philip 2008;Hassanshahian et al 2012;Kaczorek et al 2008) are capable of assimilating hydrocarbons while Malassezia was found to be active in carbon cycling of phytoplankton in coastal waters (Orsi et al 2022). On the other hand, several previous studies have shown the direct involvement of fungi in nitrogen metabolism, including ammonia assimilation and nitrate or nitrite denitrification (Wegley et al 2007;Maeda et al 2015;Civiero et al 2018).…”

Biodiversity and biocatalyst activity of culturable hydrocarbonoclastic fungi isolated from Marac–Moruga mud volcano in South Trinidad

“…Hydrocarbonoclastic fungi isolated in this study, were linked to known PAH and/or hydrocarbon degraders. Aspergillus flavus can degrade kerosene 56 , aviation fuel 57 , benzo[a]pyrene, a 5-ring priority PAH and one of the most important industrial pollutants 58 and six other PAHs among the 16 priority PAHs 59 . Phoma sp.…”

Bioprospecção de fungos filamentosos isolados de sedimentos de mangue do estado de Pernambuco para biodegradação de petroderivados

“…O mecanismo utilizado pelos fungos para biodegradar os petroderivados pode ser observado pela incorporação de um aceptor de elétrons, como o DCPIP, indicada pela mudança da cor do meio, de azul escuro a incolor (Peixoto, et al, 2018;Ribeiro, et al, 2020). Assim, esta metodologia é considerada eficaz e tem sido amplamente utilizada na seleção de micro-organismos com potencial de biodegradação (Al-Nasrawi, 2012;El Hanafy, et al, 2015;Al-Dossary, et al, 2020;Ozyurek, et al, 2021).…”

“…Dentre deles, os gêneros Aspergillus e Penicillium são considerados os mais eficientes na degradação de hidrocarbonetos, sendo relatados em inúmeras pesquisas (Saratale, et al, 2007;Al-Nasrawi, 2012;El Hanafy, et al, 2015;Ozyurek, et al, 2021). Representantes desses gêneros estão amplamente difundidos no ambiente, pois produzem estruturas reprodutivas em grande número e muito resistentes, que lhes permitem resistir a condições ambientais desfavoráveis, como baixa umidade, altas temperaturas e elevadas concentrações de petróleo bruto no solo, proporcionando-lhes uma vantagem competitiva para a sobrevivência em tais ambientes (Schwarz, et al, 2019;Al-Dossary, et al, 2020)…”