Bacterial Diversity in Old Hydrocarbon Polluted Sediments of Ecuadorian Amazon River Basins

• Published in: Toxics (Basel) Vol. 12; no. 2; p. 119
• Main Authors: Corral-García, Lara S, Molina, María Carmen, Bautista, Luis Fernando, Simarro, Raquel, Espinosa, Carlos Iván, Gorines-Cordero, Guillermo, González-Benítez, Natalia
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 31.01.2024; MDPI
• Subjects: Air temperature; Analysis; Aromatic hydrocarbons; Bacteria; bacterial diversity; Basins; Biodiversity; Biological diversity; biomarkers; Bioremediation; Crude oil; Ecuadorian Amazonia; Environmental economics; Exploitation; freshwater; Genetic aspects; hydrocarbon pollution; Hydrocarbons; Microbial activity; Microorganisms; Oil exploration; Oil spills; Petroleum; Petroleum hydrocarbons; Pollutants; Pollution; Polycyclic aromatic hydrocarbons; Pristane; Rainforests; River basins; River ecology; river sediments; Sediment pollution; Sediment samplers; Sediments; Sediments (Geology); Soil chemistry; Soil pH; Soil temperature; Spain; Ecuador; bacterial diversity; hydrocarbon pollution; freshwater; river sediments; biomarkers; Ecuadorian Amazonia
• ISSN: 2305-6304; 2305-6304
• DOI: 10.3390/toxics12020119

The Ecuadorian Amazon rainforest stands out as one of the world's most biodiverse regions, yet faces significant threats due to oil extraction activities dating back to the 1970s in the northeastern provinces. This research investigates the environmental and societal consequences of prolonged petroleum exploitation and oil spills in Ecuador's Amazon. Conducted in June 2015, the study involved a comprehensive analysis of freshwater sediment samples from 24 locations in the Rio Aguarico and Napo basins. Parameters such as water and air temperature, conductivity, soil pH, and hydrocarbon concentrations were examined. Total petroleum hydrocarbon (TPH) concentrations ranged from 9.4 to 847.4 mg kg , with polycyclic aromatic hydrocarbon (PAH) levels varying from 10.15 to 711.1 mg kg . The pristane/phytane ratio indicated historic hydrocarbon pollution in 8 of the 15 chemically analyzed sediments. Using non-culturable techniques (Illumina), bacterial analyses identified over 350 ASV, with prominent families including , , , , and . Bacterial diversity, assessed in eight samples, exhibited a positive correlation with PAH concentrations. The study provides insights into how microbial communities respond to varying levels of hydrocarbon pollution, shedding light on the enduring impact of oil exploitation in the Amazonian region. Its objective is to deepen our understanding of the environmental and human well-being in the affected area, underscoring the pressing need for remedial actions in the face of ongoing ecological challenges.