Identification of key microorganisms in facultative stabilization ponds from dairy industries, using metagenomics

IRAZOQUI, JOSE M.; EBERHARDT, MARIA F.; ADJAD, MARIA M.; AMADIO, ARIEL F.

PeerJ

PeerJ

Año: 2022 vol. 10

Wastewater stabilization ponds are a natural form of wastewater treatment. Theirlow operation and maintenance costs have made them popular, especially indeveloping countries. In these systems, effluents are retained for long periods of time,allowing the microbial communities present in the ponds to degrade the organicmatter present, using both aerobic and anaerobic processes. Even though thesesystems are widespread in low income countries, there are no studies about themicroorganisms present in them and how they operate. In this study, we analised themicrobial communities of two serial full-scale stabilization ponds systems usingwhole genome shotgun sequencing. First, a taxonomic profiling of the reads wasperformed, to estimate the microbial diversity. Then, the reads of each systemwere assembled and binned, allowing the reconstruction of 110 microbial genomes.A functional analysis of the genomes allowed us to find how the main metabolicpathways are carried out, and we propose several organisms that would be key tothis kind of environment, since they play an important role in these metabolicpathways. This study represents the first genome-centred approach to understandthe metabolic processes in facultative ponds. A better understanding of thesemicrobial communities and how they stabilize the effluents of dairy industries isnecessary to improve them and to minimize the environmental impact of dairyindustries wastewater.