Investigating the Metabolism of Estrogens in Ligilactobacillus salivarius Strains Isolated from Human Milk and Vaginal Microbiota.

The interplay between enterohepatic circulation and the gut microbiota is the main driver determining systemic levels of estrogens and their metabolites. Nevertheless, the role of potentially probiotic microorganisms in estrogen metabolism has not been investigated so far. In this work, we have explored the ability of six Ligilactobacillus salivarius strains isolated from human milk and vaginal samples to degrade and/or conjugate parental estrogens in vitro and under aerobic conditions. The quantification of estrogens and their derivatives was carried out in cell-free supernatants by LC-QQQ-MS. All the tested L. salivarius strains achieved an average degradation rate of estrone and estriol of 98% and 55%, respectively, whereas 17ß-estradiol was preferentially conjugated (up to 40%). The presence of seven out of ten genes encoding enzymes relevant for estrogen metabolism was further confirmed by PCR, highlighting their genetic potential for degrading, conjugating and/or deconjugating estrogens. The tested L. salivarius strains may be considered potential probiotics affecting the fate of endogenous estrogens. Clinical trials targeting populations with estrogen-dependent conditions will be required to elucidate the true potential of these strains for the restoration and maintenance of a healthy host estrobolome.

Upscaling the effect of traits in response to drought: The relative importance of safety-efficiency and acquisitive-conservation functional axes.

We tested the idea that functional trade-offs that underlie species tolerance to drought-driven shifts in community composition via their effects on demographic processes and subsequently on shifts in species' abundance. Using data from 298 tree species from tropical dry forests during the extreme ENSO-2015, we scaled-up the effects of trait trade-offs from individuals to communities. Conservative wood and leaf traits favoured slow tree growth, increased tree survival and positively impacted species abundance and dominance at the community-level. Safe hydraulic traits, on the other hand, were related to demography but did not affect species abundance and communities. The persistent effects of the conservative-acquisitive trade-off across organizational levels is promising for generalization and predictability of tree communities. However, the safety-efficient trade-off showed more intricate effects on performance. Our results demonstrated the complex pathways in which traits scale up to communities, highlighting the importance of considering a wide range of traits and performance processes.

Interspecies relationships between nosocomial pathogens associated to preterm infants and lactic acid bacteria in dual-species biofilms.

The nasogastric enteral feeding tubes (NEFTs) used to feed preterm infants are commonly colonized by bacteria with the ability to form complex biofilms in their inner surfaces. Among them, staphylococci (mainly Staphylococcus epidermidis and Staphylococcus aureus) and some species belonging to the Family Enterobacteriaceae are of special concern since they can cause nosocomial infections in this population. NETF-associated biofilms can also include lactic acid bacteria (LAB), with the ability to compete with pathogenic species for nutrients and space. Ecological interactions among the main colonizers of these devices have not been explored yet; however, such approach could guide future strategies involving the pre-coating of the inner surfaces of NEFTs with well adapted LAB strains in order to reduce the rates of nosocomial infections in neonatal intensive care units (NICUs). In this context, this work implied the formation of dual-species biofilms involving one LAB strain (either Ligilactobacillus salivarius 20SNG2 or Limosilactobacillus reuteri 7SNG3) and one nosocomial strain (either Klebsiella pneumoniae 9SNG3, Serratia marcescens 10SNG3, Staphylococcus aureus 45SNG3 or Staphylococcus epidermidis 46SNG3). The six strains used in this study had been isolated from the inner surface of NEFTs. Changes in adhesion ability of the pathogens were characterized using a culturomic approach. Species interactions and structural changes of the resulting biofilms were analyzed using scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). No aggregation was observed in dual-species biofilms between any of the two LAB strains and either K. pneumoniae 9SNG3 or S. marcescens 10SNG3. In addition, biofilm thickness and volume were reduced, suggesting that both LAB strains can control the capacity to form biofilms of these enterobacteria. In contrast, a positive ecological relationship was observed in the combination L. reuteri 7SNG3-S. aureus 45SNG3. This relationship was accompanied by a stimulation of S. aureus matrix production when compared with its respective monospecies biofilm. The knowledge provided by this study may guide the selection of potentially probiotic strains that share the same niche with nosocomial pathogens, enabling the establishment of a healthier microbial community inside NEFTs.

Diverging functional strategies but high sensitivity to an extreme drought in tropical dry forests.

Extreme drought events have negative effects on forest diversity and functioning. At the species level, however, these effects are still unclear, as species vary in their response to drought through specific functional trait combinations. We used long-term demographic records of 21,821 trees and extensive databases of traits to understand the responses of 338 tropical dry forests tree species to ENSO2015 , the driest event in decades in Northern South America. Functional differences between species were related to the hydraulic safety-efficiency trade-off, but unexpectedly, dominant species were characterised by high investment in leaf and wood tissues regardless of their leaf phenological habit. Despite broad functional trait combinations, tree mortality was more widespread in the functional space than tree growth, where less adapted species showed more negative net biomass balances. Our results suggest that if dry conditions increase in this ecosystem, ecological functionality and biomass gain would be reduced.

Rendimiento y resistencia a la roya (Puccinia spp. ) de líneas avanzadas de trigo (Triticum aestivum l.) en Canchan - Huánuco / Performance and resistance to the Roya (Puccinia spp. ) of lines advanced wheat (Triticum aestivum l.) in Canchan-Huánuco

Con el objetivo de determinar el rendimiento y la resistencia a la roya (Puccinia spp) de líneas avanzadas de trigo (Triticum aestivum L.) introducidas en condiciones de Canchan-Huánuco (2 020 m.s.n.m.) se evaluaron en la campaña agrícola 2008 50 líneas en el Ensayo Internacional de Rendimiento (15 SAWYT) empleando el diseño completo aleatorizado con dos repeticiones y 194 líneas en el Vivero Internacional de Selección (25 SAWSN) con una distribución sistemática sin repeticiones. Del primer experimento se seleccionaron ocho líneas promisorias con rendimientos entre 3 163.9 y 6 566.7 kg/ha con respuestas a la roya moderadamente resistente y una severidad igual o menor de 10 por ciento. En el segundo ensayo se identificaron 15 líneas superiores, con rendimientos entre 1700 y 4150 kg/ha con adecuados niveles de resistencia a la roya y tipos agronómicos que favorecen el alto rendimiento.

In order to determine the yield and resistance to rust (Puccinia spp) in advanced lines of wheat (Triticum aestivum L.) introduced in terms of Canchan-Huánuco (2020 m) were evaluated in the 2008 season in 50 lines International Yield Trial (15 SAWYT) using completely randomized design with two replications and 194 lines in the International Selection Nursery (25 SAWSN) with a systematic distribution without repetition. The first experiment, we selected eight promising lines with yields between 3163.9 / 6566.7 kg/ha with answers moderately resistant torust and a severity equal to or less than 10 per cent. In the second trial were 15 lines identified above, with yields between 1700 and 4150 kg/ha with adequate levels of resistance to rust and agronomic rates that encourage high performance.

Colecta y caracterización fenotípica de la numia (Phaseolus vulgaris L) de la cuenca del río Marañón correspondiente a la Región Huánuco / Collect and characterization phenotype of Numia (Phaseolus vulgaris L) of Basin Marañon corresponding Region Huanuco

Con el objeto de determinar la diversidad genética de la numia (Phaseolus vulgaris L), de la cuenca del río Marañon correspondiente a la Región Huánuco, se realizó un viaje de colecta para obtener las accesiones a ser caracterizadas fenotipicamente mediante descriptores cualitativos y cuantitativos. Las 14 accesiones colectadas, consideradas representativas de la variabilidad de la especie objetivo en la zona de estudio, fueron agrupados aplicando el análisis de agrupamiento "cluster análisis" obteniendo los fenogramas correspondientes. Mediante el análisis de componentes principales, se tranformaron las características correlacionadas en uno nuevo que explican mejor la variabilidad entre las accesiones y reduciendo el número de variables. El agrupamiento con los caracteres cualitativos a un coeficiente de distancia de 0.22, permitió la formación de 6 grupos taxonómicos representativos de la diversidad de la numia. Los 4 primeros componentes principales explicaron el 66.45% de la variación y los caracteres seleccionados por su capacidad explicatoria fueron: posición del pico de la vaina, forma de la semilla, venación de la semilla y el color de las alas. La accesión huacaybambina demostró su potencial para el mejoramiento genetic.

In order to determining the genetic diversity of the numia (Phaseolus vulgaris L.), of the basin of the river Marañon corresponding to the Región Huanuco, was carried out a collection trip to obtain the accesions to be fenotipic characterized by means of qualitative and quantitative descriptors. The 14 collected accesions, considered representative of the variability of the objective species of the study área, they were contained applying the cluster analysis obtaining the corresponding fenograms. By means of the analysis of main components, the characteristics correlated In one transformed new that explain the variability better among the accesions, reducing the number of variables. The clustering with the qualitative characters, to a coefficient of distance of 0.22, allowed the formation of 6 representative taxonomic groups of the diversity of the numia. The first 4 main components explained 66.45% of the variation and the characters selected by their capacity to explain they were: position of the pick of the sheath, forms of the seed, furrow of the seed and the color of the wings. The accessions Huacaybambina demonstrated its potential for the genetic improvement.