Microbial metallophores are low-molecular-weight chelating agents produced by microorganisms to acquire essential metal ions. Their biosynthesis, transport, and regulation involve complex processes, specialized enzymatic machinery, and intricate regulatory networks. This review examines the multifaceted roles of metallophores in microbial ecology and their potential applications in sustainable agriculture, emphasizing their key role in trace metal acquisition, nutrient cycling, and plant–microbe interactions. Furthermore, it explores the potential applications of metallophores in agriculture, bioremediation, and biotechnology, connecting their potential to the development of novel strategies for sustainable agriculture.

The COVID-19 pandemic has caused a decrease in outdoor activities, but an increase in indoor ones. This change in the intensity of land use has caused changes in pollution patterns. Urban dust contaminated with heavy metals can be a risk to the human population. Therefore, the objective of this work was to evaluate the pollution caused by heavy metals in urban dust indoors and outdoors due to changes in land use during the pandemic. Sampling was carried out by the Gomez Palacio citizens. The total number of urban dust samples was 330, 50% indoor samples and 50% outdoor sample. The elements studied were Ca, Cu, Fe, K, Mn, Ni, Pb, Rb, Sr, Ti, Y, Zn, and Zr. The heavy metals were measured through a portable XRF; the contamination factor and the load pollution index were used to assess the pollution level. The human health risk was evaluated with the USEPA methodology. Cu, Pb, and Zn presented higher concentrations indoors than outdoors, probably due to domestic factors, such as the age of the houses and the paint on the walls. Zn presented the highest pollution level among all the metals, outdoors and indoors; spatially, the sites sampled in the northwest, close to agricultural areas, presented the highest Zn pollution. Pb had a moderate pollution level in most of the samples (60%), but some samples showed a high Pb pollution. The health risk was considered within the acceptable levels for Cu, Fe, Ni, Pb, Zn. However, Mn deserves attention because the average of the samples slightly exceeded the USEPA safety limits for children. Children are at higher risk compared to adults. Indoor environments need to be better analyzed because they were shown to represent a higher risk to the population than outdoor ones due to heavy metal pollution by Zn, Cu, and Pb. The pandemic impacted land use intensity; this study reports an apparent effect of the pandemic on the amount and type of heavy metals indoors and outdoors.

Antecedentes: A nivel mundial se han realizado varios estudios relacionados con macrohongos y metales pesados, pero en México existen pocos registros al respecto. Anteriormente en la zona de la Comarca Lagunera se han registrado niveles de metales pesados en diversos organismos. Objetivos: Este trabajo tiene como objetivo determinar la concentración de metales pesados (Cd, Cu, Pb y Zn) en especies fúngicas en la zona metropolitana de la Comarca Lagunera, México. Métodos: Se realizaron dos recolectas anuales (2017-2018) en 30 sitios pertenecientes a principales áreas verdes y avenidas de tres municipios de la Comarca Lagunera. La identificación de los ejemplares se realizó mediante técnicas de micología básica y literatura especializada. En cuanto a la medición de metales se empleó la espectroscopía de absorción atómica con aspiración directa. Resultados y conclusiones: Se obtuvieron un total de 32 muestras, pertenecientes a nueve especies. Los resultados mostraron concentraciones altas en las nueve especies analizadas, sobrepasando los parámetros de límites permisibles por estándares europeos.

Dasylirion cedrosanum is a native species of the Chihuahuan Desert that is economically important for alcohol production, which has caused its looting and deforestation. In the micropropagation technique, the Murashige and Skoog (MS) basal medium is the most widely used, this basal medium increases costs at the commercial level. The objective of this work was to compare the MS medium with an organic basal medium made from a vermicompost extract (EV) in the multiplication and rooting stages of D. cedrosanum. Seeds were established in MS medium for germination. Then, the seedlings obtained were used as secondary explants for the multiplication stage. In the multiplication stage, seven treatments were evaluated under a completely randomized design with 10 replications. A control (MS medium) and six EV concentrations (30, 25, 20, 15, 10 and 5 mL L-1) were compared. Our results showed the highest sprout formation in the control treatment (8.25 sprouts per explant). Whereas in the EV base treatments, the 25 ml L‑1 concentration exhibited the highest number of sprouts (3 sprouts per explant). It is worth noting that no significant differences were found between the control and the 25 ml L-1 concentration treatments in terms of the number of variables and leaf length. In the rooting stage, there was no significant difference between treatments in the root number. The MS medium and 10 ml L-1 of EV was not statistically different according to root length (6.53 and 5.99 cm, respectively), the 10 ml L-1 concentration of EV surpassed the MS in root width (1.13 mm). The EV based medium at a concentration of 10 ml L-1 can be used to completely to replace the MS medium in the rooting stage of D. cedrosanum.

This research aimed to evaluate the effectiveness of the biosynthesized spherical zinc oxide nanoparticles (BZnONPs) applications on morphological and physiological indices of serrano pepper plants cv. ‘Chiser-522’. The treatments applied by foliar spray every 15 days from 20 days after transplantation consisted of 10, 20, 30, 40, and 50 ppm of BZnONPs and control (distilled water). A completely randomized design was used with six treatments and fifteen replicas per treatment. Morphological and physiological characteristics such as crop growth rate (CGR), net assimilation rate (NAR), leaf area index (LAI), photosynthetic pigments, and phytochemical compounds were evaluated. The results indicated that the plants treated with 30 and 40 ppm of BZnONPs had higher height, thicker stems, longer roots, and higher CGR, NAR, and LAI than control. Their amounts of photosynthetic pigments and antioxidant compounds were also increased compared to those of the other treatments. Therefore, we conclude that BZnONPs are promising technology that significantly influences chili pepper cultivation's physiological and morphological development at low-level exposures.

Globally, freshwater resources in semi-arid areas are heavily strained; for this reason, to take care of this resource, domestic wastewater is used to irrigate crops. A concern associated with this practice is the potential accumulation of heavy metal(loid)s (HMs) in soil and plants. A field experiment was conducted to evaluate the accumulation of HMs in barley and oats irrigated with treated domestic wastewater (TWW) compared to those irrigated with groundwater (GW). The content of As, Cd, Fe, Mn, Ni, Pb, and Zn in soil and plants (root, stem, leaves, and grain) were determined. The content of all HMs for both water sources was significantly higher in the roots and leaves, minor in the stem, and minimum in grains. The amount of Cd and Pb in grain was below the recommended guideline set by the FAO/WHO while As was slightly above the guideline. Arsenic in the roots of both crops was higher for those irrigated with GW. Bioconcentration factor and translocation factors showed a minor tendency of plants to accumulate metals in leaves and grain. Also, soils irrigated with TWW had a reduced sodium content (SAR, ESP) than those irrigated with GW. With a reported increase in grain yield of about >50%, no significant difference in HMs accumulation, and less soil salinization using TWW concerning GW, the benefits of irrigating barley and oats with TWW stand out. However, monitoring soil salinity and potential accumulation of HMs or other toxic contaminants for the duration of TWW irrigation is recommended.