RESUMEN
Wastewater stabilization ponds are a natural form of wastewater treatment. Their low operation and maintenance costs have made them popular, especially in developing countries. In these systems, effluents are retained for long periods of time, allowing the microbial communities present in the ponds to degrade the organic matter present, using both aerobic and anaerobic processes. Even though these systems are widespread in low income countries, there are no studies about the microorganisms present in them and how they operate. In this study, we analised the microbial communities of two serial full-scale stabilization ponds systems using whole genome shotgun sequencing. First, a taxonomic profiling of the reads was performed, to estimate the microbial diversity. Then, the reads of each system were assembled and binned, allowing the reconstruction of 110 microbial genomes. A functional analysis of the genomes allowed us to find how the main metabolic pathways are carried out, and we propose several organisms that would be key to this kind of environment, since they play an important role in these metabolic pathways. This study represents the first genome-centred approach to understand the metabolic processes in facultative ponds. A better understanding of these microbial communities and how they stabilize the effluents of dairy industries is necessary to improve them and to minimize the environmental impact of dairy industries wastewater.
Asunto(s)
Microbiota , Aguas Residuales , Estanques , Industria Lechera , Microbiota/genética , Genoma MicrobianoRESUMEN
Two synthetic bacterial consortia (SC) composed of bacterial strains Sphingobium sp. (AM), Klebsiella aerogenes (B), Pseudomonas sp. (Bc-h and T), Burkholderia sp. (Bk) and Inquilinus limosus (Inq) isolated from a natural phenanthrene (PHN)-degrading consortium (CON) were developed and evaluated as an alternative approach to PHN biodegradation in bioremediation processes. A metabolic network showing the potential role of strains was reconstructed by in silico study of the six genomes and classification of dioxygenase enzymes using RHObase and AromaDeg databases. Network analysis suggested that AM and Bk were responsible for PHN initial attack, while Inq, B, T and Bc-h would degrade PHN metabolites. The predicted roles were further confirmed by physiological, RT-qPCR and metaproteomic assays. SC-1 with AM as the sole PHN degrader was the most efficient. The ecological roles inferred in this study can be applied to optimize the design of bacterial consortia and tackle the biodegradation of complex environmental pollutants.
RESUMEN
In northwestern Argentina (NWA), pepper crops are threatened by the emergence of begomoviruses due to the spread of its vector, Bemisia tabaci (Gennadius). The genus Begomovirus includes pathogens that can have a monopartite or bipartite genome and are occasionally associated with sub-viral particles called satellites. This study characterized the diversity of begomovirus and alphasatellite species infecting pepper in NWA using a metagenomic approach. Using RCA-NGS (rolling circle amplification-next generation sequencing), 19 full-length begomovirus genomes (DNA-A and DNA-B) and one alphasatellite were assembled. This ecogenomic approach revealed six begomoviruses in single infections: soybean blistering mosaic virus (SbBMV), tomato yellow spot virus (ToYSV), tomato yellow vein streak virus (ToYVSV), tomato dwarf leaf virus (ToDfLV), sida golden mosaic Brazil virus (SiGMBRV), and a new proposed species, named pepper blistering leaf virus (PepBLV). SbBMV was the most frequently detected species, followed by ToYSV. Moreover, a new alphasatellite associated with ToYSV, named tomato yellow spot alphasatellite 2 (ToYSA-2), was reported for the first time in Argentina. For the Americas, this was the first report of an alphasatellite found in a crop (pepper) and in a weed (Leonurus japonicus). We also detected intra-species and inter-species recombination.