Diseño y utilización de unas prácticas de Regulación del Metabolismo como herramienta integradora de conocimientos multidisciplinares en el Grado en Biología (II)

Se pretende la creación de espacios multidisdiplinares en el Grado en Biología,con prácticas integradas de asignaturas que se cursan simultáneamente, que pudieran servir de base a propuestas de Trabajos de Fin de Grado

Niche differentiation drives microbial community assembly and succession in full-scale activated sludge bioreactors

Network models and community phylogenetic analyses are applied to assess the composition, structure, and ecological assembly mechanisms of microbial communities. Here we combine both approaches to investigate the temporal dynamics of network properties in individual samples of two activated sludge systems at different adaptation stages. At initial assembly stages, we observed microbial communities adapting to activated sludge, with an increase in network modularity and co-exclusion proportion, and a decrease in network clustering, here interpreted as a consequence of niche specialization. The selective pressure of deterministic factors at wastewater treatment plants produces this trend and maintains the structure of highly functional and specialized communities responding to seasonal environmental changes

La curación de contenidos científicos como estrategia didáctica y divulgativa en Microbiología y otras áreas afines

Fac. de Ciencias BiológicasFALSEsubmitte

Creación del primer Grupo iGEM (Competición Internacional de Biología Sintética) de Madrid: Facultad de Biología-UCM

En este Trabajo se describe la creación del primer Grupo iGEM de Madrid así como la elaboración de un biosensor que permite la detección de polen de olivo a tiempo real empleando metodos de ingeniería genética y robótica

Unravelling the interactions among microbial populations found in activated sludge with incidence on biofilm formation

Microorganisms colonize surfaces and develop biofilms through interactions not yet thoroughly understood, with important implications in water and wastewater systems. This study has investigated the interactions between N-acyl homoserine lactone (AHL)-producing bacteria, yeasts and protists, and their contribution to biofilm development. Sixty-one bacterial strains were isolated from activated sludge and screened for AHL production, with Aeromonas sp. found to be the dominant AHLproducer. Shewanella xiamenensis, Aeromonas allosaccharophila, Acinetobacter junii and Pseudomonas aeruginosa recorded the highest adherence capabilities, with S. xiamenensis being the most effective in surface colonization. Additionally, highly significant interactions (i.e., synergic or antagonistic) were described for dual and multistrain mixtures of bacterial strains (P. aeruginosa, S. xiamenensis, A. junii and P. stutzeri), as well as for strongly adherent bacteria co-cultured with yeasts. In this last case, the adhered biomass in co-cultures was lower than the monospecific biofilms of bacteria and yeast, with biofilm observations by microscopy suggesting that bacteria had an antagonist effect on the whole or part of the yeast population. Finally, protist predation by Euplotes sp. and Paramecium sp. on A. hydrophila biofilms not only failed to reduce biofilm formation, but also recorded unexpected results leading to the development of aggregates of high density and complexity

Membrane bioreactor wastewater treatment plants reveal diverse yeast and protist communities of potential significance in biofouling

The yeast community was studied in a municipal full-scale membrane bioreactor wastewater treatment plant (MBR-WWTP). The unexpectedly high diversity of yeasts indicated that the activated sludge formed a suitable environment for them to proliferate, with cellular concentrations of 2.2 ± 0.8 × 103 CFU ml−1 . Sixteen species of seven genera were present in the biological reactor, with Ascomycetes being the most prevalent group (93%). Most isolates were able to grow in a synthetic wastewater medium, adhere to polyethylene surfaces, and develop biofilms of variable complexity. The relationship between yeast populations and the protists in the MBR-WWTP was also studied, revealing that some protist species preyed on and ingested yeasts. These results suggest that yeast populations may play a role in the food web of a WWTP and, to some extent, contribute to membrane biofouling in MBR systems

Diseño y utilización de unas prácticas de Regulación del Metabolismo como herramienta integradora de conocimientos multidisciplinares en el Grado en Biología

Con el diseño de estas prácticas de laboratorio se pretende la creación de espacios multidisdiplinares en el Grado en Biología que puedieran dar paso a un futuro modelo de prácticas integradas de asignaturas que se cursan simultáneamente

La Microbiología a debate

Depto. de Genética, Fisiología y MicrobiologíaFac. de Ciencias BiológicasFALSEsubmitte

Quorum Sensing versus Quenching Bacterial Isolates Obtained from MBR Plants Treating Leachates from Municipal Solid Waste

Quorum sensing (QS) is a mechanism dependent on bacterial density. This coordinated process is mediated by the synthesis and the secretion of signal molecules, called autoinducers (AIs). N-acyl-homoserine lactones (AHLs) are the most common AIs that are used by Gram-negative bacteria and are involved in biofilm formation. Quorum Quenching (QQ) is the interference of QS by producing hydrolyzing enzymes, among other strategies. The main objective of the present study was to identify QS and QQ strains from MBR wastewater treatment plants. A total of 99 strains were isolated from two Spanish plants that were intended to treat leachate from municipal solid waste. Five AHL producers were detected using AHL biosensor strains (Chromobacterium violaceum CV026 and Agrobacterium tumefaciens NT1). Fifteen strains of seventy-one Gram-positive were capable of eliminating or reducing at least one AHL activity. The analysis of 16S rRNA gene sequence showed the importance of the Pseudomonas genus in the production of biofilms and the relevance of the genus Bacillus in the disruption of the QS mechanism, in which the potential activity of lactonase or acylase enzymes was investigated with the aim to contribute to solve biofouling problems and to increase the useful lifespan of membranes