Avaliação do potencial biorremediador de um consórcio bacteriano em diferentes tipos de óleo diesel

Abstract

Hydrocarbon contamination in the Amazon region represents a significant environmental challenge, particularly in areas subjected to intense port activity. Despite the recognized microbial potential of the Amazon, autochthonous consortia capable of degrading hydrocarbons remain largely unexplored. In this study, a microbial consortium isolated from the waters of the Negro River in the Manaus region (AM) was characterized, cultivated in Bushnell Haas medium supplemented with 1% diesel oil. Biodegradation efficiency was evaluated by mass spectrometry, with quantification of alkanes. After seven days of incubation, the consortium exhibited degradation rates exceeding 98 ± 2.26% for S10 diesel and 89 ± 2.23% for marine diesel (ODM). Metataxonomic analysis based on 16S rRNA gene sequencing revealed high bacterial diversity, with 16 genera identified, including Achromobacter spp., Bordetella spp., Burkholderia spp., Castellaniella spp., and Pseudomonas spp. ITS marker analysis identified six fungal genera, with predominance of sequences assigned to Meyerozyma spp. From the isolation of consortium morphotypes, three bacterial strains were characterized at the genus level through partial 16S rRNA gene analysis and scanning electron microscopy: strain A5C4 was assigned to Pseudomonas sp., while A5C2 and A5C9 were identified as Achromobacter sp. Additionally, the consortium promoted a reduction of more than 46 ± 1.1% in the medium’s surface tension, as determined by tensiometry, indicating biosurfactant production. Overall, the results demonstrate the proven efficiency of the Amazonian microbial consortium in diesel oil degradation, representing an important scientific contribution for future studies on the bioremediation of hydrocarbon-contaminated environments.