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This work has been supported by grant PID2019‐105834GA‐I00 (acronym Wineteractions) funded by the Spanish State Research Agency/Science and Research Ministry (https://doi.org/10.13039/501100011033). Javier Ruiz acknowledges the Spanish State Research Agency/Science and Research Ministry for his postdoctoral contract Juan de la Cierva‐formación 2021 (FJC2021‐046516‐I). Alvaro Sanchez was Funded/Co‐Funded by the European Union (ERC, ECOPROSPECTOR‐101088469), Predictively linking taxonomic composition and quantitative ecosystem functions is a major aspiration in microbial ecology, which must be resolved if we wish to engineer microbial consortia. Here, we have addressed this open question for an ecological function of major biotechnological relevance: alcoholic fermentation in wine yeast communities. By exhaustively phenotyping an extensive collection of naturally occurring wine yeast strains, we find that most ecologically and industrially relevant traits exhibit phylogenetic signal, allowing functional traits in wine yeast communities to be predicted from taxonomy. Furthermore, we demonstrate that the quantitative contributions of individual wine yeast strains to the function of complex communities followed simple quantitative rules. These regularities can be integrated to quantitatively predict the function of newly assembled consortia. Besides addressing theoretical questions in functional ecology, our results and methodologies can provide a blueprint for rationally managing microbial processes of biotechnological relevance., Depto. de Genética, Fisiología y Microbiología, Fac. de Ciencias Biológicas, TRUE, pub

Funding for the research in this paper was provided by Agrovin S.A, under the framework of the CDTI-financed project IDI-20160102 and by Pago de Carraovejas S.L. CDTI-financed project IDI-20160750 (Centre for Industrial Technological Development, Spanish Ministry of Economy, Industry and Competitiveness, Spain)., Most wine aroma compounds, including the varietal fraction, are produced or released during wine production and derived from microbial activity. Varietal aromas, typically defined as terpenes and thiols, have been described as derived from their non-volatile precursors, released during wine fermentation by different yeast hydrolytic enzymes. The perception of these minority aroma compounds depends on the chemical matrix of the wine, especially on the presence of majority aroma compounds, such as esters or higher alcohols. Strategies aiming to reduce the production of these masking flavors are on the spotlight of enology research as a way to better define varietal standard profiles for the global market. Using a natural white must from Verdejo variety (defined as a thiol grape variety), here we describe the analytical and sensorial impact of using, in sequential inoculations, a selected strain of Metschnikowia pulcherrima, in combination with two different Saccharomyces cerevisiae strains. An increase in the levels of the thiol 4-MSP (4-methyl-4-sulfanylpentan-2-one) over its sensory threshold, together with a decrease in higher alcohol production, was observed when M. pulcherrima was used. This has an important impact on these wines, making them fruitier and fresher, always preferred by the sensory panel., Depto. de Genética, Fisiología y Microbiología, Fac. de Ciencias Biológicas, TRUE, pub

Depto. de Genética, Fisiología y Microbiología, Fac. de Ciencias Biológicas, TRUE, pub

El funcionamiento de las Estaciones de Depuración de Agua Residual (EDAR) depende de la actividad de la comunidad microbiana para la degradación de la materia orgánica y de los nutrientes presentes en el agua residual. En los procesos de fango activo estos microorganismos se agrupan junto a la materia en suspensión para formar flóculos, que se separarán de la fase líquida para verter el agua tratada al medio de manera segura. Uno de los sistemas más utilizados para realizar esta separación es la utilización de membranas de filtración en biorreactores de membrana (MBR). En esta Tesis Doctoral se estudió la estructura y la dinámica de las comunidades microbianas en un biorreactor de EDAR-MBR a lo largo de dos años. Esta comunidad presentó un patrón de sucesión estacional, determinado por la temperatura, con una cierta deriva que produjo cambios significativos entre ambas anualidades. Una pequeña fracción de los filotipos detectados conformaron gran parte de la comunidad bacteriana, constituyendo un microbioma “core”, cuya estabilidad también está claramente determinada por la temperatura. Los patrones de estabilidad de esta comunidad se pueden inferir y monitorizar para determinar si la comunidad está funcionando correctamente. Mediante el uso de modelos basados en redes microbianas y análisis filogenéticos observamos que la sucesión de la microbiota del biorreactor consistía en la alternancia de dos sub-comunidades con distintas afinidades ambientales, que dominaban alternativamente en los meses cálidos y fríos. Además, la presión selectiva que ejerce el ambiente del biorreactor selecciona y mantiene una comunidad altamente funcional y especializada que responde a los cambios ambientales estacionales. Estos resultados se contrastaron con el análisis de una comunidad microbiana en proceso de adaptación al nuevo biorreactor donde había sido inoculada, observándose un patrón de ensamblaje que refleja la tendencia de la comunidad a ser cada vez más modular y especializad, The operation of Wastewater Treatment Plants (WWTP) depends on the activity of the microbial community for the degradation of organic matter and nutrients present in the wastewater. In activated sludge processes, these microorganisms are grouped together with the suspended matter to form flocs, which will be separated from the liquid phase, to discharge the treated water safely into the environment. One of the most widely used systems for this separation is the use of membrane filtration in membrane bioreactors (MBR). In this Doctoral Thesis, the structure and dynamics of the microbial communities in a WWTP-MBR bioreactor were studied over a period of two years. This community presented a seasonal succession pattern, determined by temperature, with a certain drift that produced significant changes between both sampled years. A small fraction of the phylotypes detected formed a large part of the bacterial community, constituting a "core" microbiome, whose stability is also clearly determined by temperature. The stability patterns of this community can be inferred and monitored to determine whether the community is functioning properly. Using microbial network-based modeling and phylogenetic analysis, we observed that the succession of the bioreactor microbiota consisted of alternating two sub-communities with different environmental affinities, which alternately dominated in the warm and cold months. Furthermore, the selective pressure exerted by the bioreactor environment selects and maintains a highly functional and specialized community that responds to seasonal environmental changes. These results were contrasted with the analysis of a microbial community adapting to the new bioreactor where it had been inoculated, observing an assemblage pattern that reflects the tendency of the community to become increasingly modular and specialized...

Alonso de Ercilla, La Araucana, edición crítica y estudio de Luis Gómez Canseco, Madrid, Real Academia Española, 2022, 1468 pp. ISBN 9788467064834