Characterization of sediments from the upper basin of the Lerma River, Mexico: Microbiome and biomethane potential

Abstract

The Lerma River’s high pollution has changed its environmental conditions. Therefore, in batch cultures, the present work characterized the sediments from the Lerma River, where the methane production and the structure of the microflora were evaluated in three sampling points. Biomass was taken from an anaerobic Waste Water Treatment Plant (WWTP) as a control sludge. Results showed that the glucose degradation rate of the control was 48 times faster than the degradation rate of the sediments; however, the substrate degradation rates presented by the three sediments were similar, with chemical oxygen demand (COD) removal efficiencies higher than 95%. Regarding the Biomethane Potential (BMP), the control and the three sediments presented high BMP. Finally, the sediments showed the potential to produce methane, and the main microflora identified in the sediments were delta-proteobacteria, beta-proteobacteria, clostridia, bacteroidia, and methanomicrobia; these classes are involved in each stage of anaerobic digestion