Pollution of freshwater ecosystems from polycyclic aromatic hydrocarbons (PAHs) is a global concern. The US Environmental Protection Agency (EPA) has included the PAHs pyrene, phenanthrene, and naphthalene among the 16 priority compounds of special concern for their toxicological effects. The aim of this study was to adapt and characterize a microbial consortium from ore waste with the potential to remove these three PAHs from water. This microbial consortium was exposed to the target PAHs at levels of 5, 10, 20, 50, and 100 mg L−1 for 14 days. PAH bioremoval was measured using the analytical technique of solid phase microextraction, followed by gas chromatography mass spectrometry (SPME-GC/MS). The results revealed that up to 90% of the target PAHs can be removed from water after 14 days at a concentration level of 100 mg L−1. The predominant group of microorganisms identified at the phylum taxonomic level were the Proteobacteria, while the Actinobacteria were the predominant subgroup. The removal of phenanthrene, naphthalene, and pyrene predominantly occurred in specimens of genera Stenotrophomonas, Williamsia, and Chitinophagaceae, respectively. This study demonstrates that the use of specific microorganisms is an alternative method of reducing PAH levels in water.

Our study shows that the molecular approach with 16S rDNA-DGGE identifies twofold more pathogenic bacteria than bacteriological culture, including complex bacterial communities associated with the development of bacterial sepsis in neonates. What is Known: • Neonatal sepsis affects 2.3% of birth in the NICU with a high mortality risk. • Evidence supports the use of molecular methods as an alternative to blood culture for identification of bacterial associated neonatal sepsis. What is New: • The DGGE gel is a good methodological approach for the identification of bacterial in neonatal blood samples. • This study describes the pattern of electrophoretic mobility obtained by DGGE gels and allows to determine the type of bacteria associated in the development of neonatal sepsis.

Phytoremediation is a feasible alternative to remediate soils polluted with toxic elements, which can be enhanced by manipulating plant-microbe interactions. Regarding this, free-living saprophytic fungi that interact beneficially with roots have been scarcely studied. Thus, the aim of this study was to assess the effect of a saprophytic fungus, Lewia sp., on the plant growth and the ability of Dodonaea viscosa to phytoaccumulate or phytostabilize soluble and insoluble sources of lead in a solid support. The growth of D. viscosa was influenced by both Pb and Lewia sp. While seedlings exposed to Pb showed a decrease in biomass production, in seedlings grown without Pb the biomass was stimulated by Lewia sp. The fungus strongly stimulated the weight-to-length ratio in roots. Regardless of the treatment, D. viscosa accumulated 4.4-6.5 times more Pb in roots than in shoots, conducting to low translocation factors (< 0.2). The presence of Lewia sp. significantly improved Pb accumulation, achieving high bioconcentration factors (> 22), which was attributed to an increased bioavailability and uptake of Pb due to the fungus. This study demonstrated that Lewia sp. could improve Pb-phytostabilization by D. viscosa in soils polluted with soluble and insoluble forms of Pb.

The amount of sargassum seaweed washed ashore on the beaches of Africa, Brazil, Central America and the Caribbean has increased to the point where it has become a social, environmental and financial issue. This research evaluates the potential for Sargassum spp. of the Mexican Caribbean coast to be used in the production of biomethane by estimating: a) stoichiometric methane production (SMP), b) biochemical methane potential (BMP) and c) biodegradability index (BI).The use of a sigmoidal model generalized to substrate to inoculum ratios is proposed, to predict the biomethane production during the anaerobic digestion (AD) of the sargassum. The information obtained shows the seaweed's potential for biomethane production and will be useful for estimates and scaling when implementing energy harnessing systems for sargassum in the Caribbean. The use of biomass is a key element in the move towards a circular economy. It is hoped that the use of technologies like AD leads to the integration of this seaweed into an economic value chain, thereby reducing the adverse effects of its presence on the ecosystem.

Water quality is relevant due to the complexity of the interaction of physicochemical and biological parameters. The Irrigation District 005 (ID005) is one of the most important agricultural region in Chihuahua, México; for that reason, it was proposed to investigate the water quality of the site. Water samples were collected in two periods: Summer (S1) and Fall (S2). The samples were taken from 65 wells in S1, and 54 wells in S2. Physicochemical parameters (PhP) such as Arsenic (As), Temperature, Electrical Conductivity (EC), Oxide Reduction Potential (ORP), Hardness, pH, Total Dissolved Solids (TDS), and Turbidity were analyzed. The data were subjected to statistical principal component analysis (PCA), cluster analysis (CA) and spatial variability tests. In both seasons, the TDS exceeded the Mexican maximum permissible level (MPL) (35% S1, 39% S2). Turbidity exceeded the MPL in S1 (29%) and in S2 (12%). Arsenic was above the MPL for water of agricultural use in 9% (S1) and 13% (S2) of the wells. The PCA results suggested that most variations in water quality in S1 were due to As, pH and Temperature, followed by EC, TDS and Hardness; while in S2 to EC, TDS and Hardness, followed by As and pH.