Extremophile deep-sea viral communities from hydrothermal vents: Structural and functional analysis

Ten publicly available metagenomic data sets from hydrothermal vents were analyzed to determine the taxonomic structure of the viral communities present, as well as their potential metabolic functions. The type of natural selection on two auxiliary metabolic genes was also analyzed. The structure of the virome in the hydrothermal vents was quite different in comparison with the viruses present in sediments, with specific populations being present in greater abundance in the plume samples when compared with the sediment samples. ssDNA genomes such as Circoviridae and Microviridae were predominantly present in the sediment samples, with Caudovirales which are dsDNA being present in the vent samples. Genes potentially encoding enzymes that participate in carbon, nitrogen and sulfur metabolic pathways were found in greater abundance, than those involved in the oxygen cycle, in the hydrothermal vents. Functional profiling of the viromes, resulted in the discovery of genes encoding proteins involved in bacteriophage capsids, DNA synthesis, nucleotide synthesis, DNA repair, as well as viral auxiliary metabolic genes such as cytitidyltransferase and ribonucleotide reductase. These auxiliary metabolic genes participate in the synthesis of phospholipids and nucleotides respectively and are likely to contribute to enhancing the fitness of their bacterial hosts within the hydrothermal vent communities. Finally, evolutionary analysis suggested that these auxiliary metabolic genes are highly conserved and evolve under purifying selection, and are thus maintained in their genome

Evaluation of Health Risks Due to Heavy Metals in a Rural Population Exposed to Atoyac River Pollution in Puebla, Mexico

The health risks of Emilio Portes Gil’s population, for the exposition to the Atoyac River pollution in the State of Puebla, was evaluated. The objective was to determine the concentration of nine heavy metals by ingesting water from wells and spri ngs. The chronic daily water intake (CDI), hazard quotient (HQ), hazard index (HI), and carcinogenic risk index (CRI) in adults, teenagers, and children were estimated. The results showed that the concentration of Fe, Al, Ni, and Pb in some of the samples exceeded the recommended standards for human consumption and was significantly higher in the dry season. The hazard index (HI), due to the collective intake of metals, was higher in children (>50% compared to adults), due to the consumption of spring water in the dry season. Risk of noncancerous diseases was not detected in the long term, since the indices did not exceed the unit (reference value). The carcinogenic risk from oral exposure to Cr (CRIchildren = 3.2 × 10−4), was greater than the acceptable limit (1 × 10−6) in the water spring, and Cr and Pb were the main metals that contributed to the potential health risk of the inhabitants. The study showed the risks by the intake of polluted water from the sources of supply in the region, and that the risk is higher in the dry season (>100% compared with rainy season)