Análisis del metabolismo, las funciones, la ecología y la taxonomía del género Pseudomonas

[ES] Los microorganismos habitan los distintos ecosistemas de la naturaleza, incluyendo plantas y animales. Para ello, deben haber evolucionado y haberse adaptado a cada una de las condiciones ambientales del lugar en el que viven. Los microorganismos juegan un papel muy importante en cada nicho, influyendo en los ciclos biogeoquímicos y, en el caso de hospedadores pluricelulares, participando en su nutrición y defensa, entre otros roles. Por lo tanto, el estudio de la ecología y funciones de los microorganismos puede ayudar a explicar la vasta complejidad de la naturaleza. Además, este conocimiento puede ser de ayuda para el desarrollo y aplicación en industria, biotecnología y clínica de nuevos procesos microbianos. Las Pseudomonas constituyen uno de los géneros procariotas más diversos y adaptables. Su versatilidad metabólica les permite sobrevivir en ambientes muy distintos. Se han identificado Pseudomonas en seres humanos, plantas, suelos, ríos, profundidades marinas, ambientes psicrófilos, insectos y en muchos otros nichos u hospedadores. Esta diversidad de ambientes en los que las bacterias del género Pseudomonas evolucionan ha dado lugar a una amplia diversificación de sus miembros, de manera que se erigen como uno de los géneros bacterianos más diversos. Esta alta diversidad, junto con su versatilidad y su facilidad de ser cultivadas en condiciones de laboratorio, da lugar a un descubrimiento constante de nuevas especies bacterianas pertenecientes a este género. En esta tesis se han llevado a cabo distintas aproximaciones para descifrar nuevas funciones y aspectos ecológicos del género Pseudomonas. [EN] Microbes live in almost all the different ecosystems in nature, including plants and animals. For that, they must have evolved and adapted to each of the different environmental conditions where they appear. In each niche, microbes play very important roles, such as in biogeochemical cycles and, in case of pluricellular hosts, in host nourishment and defense, amongst others. Thus, the study of the ecology and functions of microbes may help to explain the complexity of nature. Also, this knowledge may be helpful for the development and application of new microbial processes for industrial, biotechnological and clinical purposes. Pseudomonas bacteria constitute one of the most diverse and adaptable prokaryotic genera. Their metabolic versatility allows them to survive in many different environments. Members of Pseudomonas have been identified in human beings, plants, soils, rivers, deep seas, psychrophilic environments, insects and other environmental niches or hosts. The diversity of environments where Pseudomonas bacteria evolve and diversify has led to a broad evolution of its members, thus being one of the most diverse bacterial genera. This high diversity of the genus plus its versatility and easy growth in laboratory conditions results in a continuous discovery of new species classified within the genus. In this thesis, different approaches have been carried out in order to decipher novel functionalities and ecological aspects of the genus Pseudomonas

Farmaconciencia. Realización de un programa de concienciación sobre el uso imprudente de medicamentos en oficinas de farmacia con alumnos de prácticas tuteladas de la facultad de farmacia: resistencia a los antibióticos

Memoria ID-204. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2019-2020

Bio-prospecting for antibiotic producing bacteria from the rhizospheric culturome

The inappropriate use of antibiotics has increased the number illnesses and deaths because of multidrug resistant microbial caused infections. The objective of this study was to isolate rhizospheric bacteria and evaluate their potential to produce antimicrobial compounds. 418 bacterial colonies were isolated and assayed against bacteria and fungi in order to analyze their antimicrobial potential, finding 114 antimicrobial producing strains. Two of these strains with best antimicrobial spectrum of action were selected for further analyses, and were identified as Bacillus albus and Streptomycs cirratus. Their genomes were sequenced and secondary metabolism pathways were analyzed, finding genetic machinery potentially implicated in the production of new bioactive compounds.El consumo indebido de antibióticos ha incrementado el número de personas que enferman y mueren por infecciones provocadas por microorganismos resistentes a estos antimicrobianos. El objetivo de este estudio fue aislar bacterias rizosféricas y evaluar su potencial para producir nuevos compuestos antimicrobianos. Se aislaron 418 colonias y se enfrentaron a bacterias y hongos para analizar su potencial antimicrobiano, encontrando 114 bacterias productoras de antibiótico. Se seleccionaron dos de las cepas con mejor espectro antimicrobiano de acción, que se identificaron como Bacillus albus y Streptomyces cirratus. Se secuenciaron sus genomas y se analizaron las rutas relacionadas con el metabolismo secundario bacteriano, encontrando maquinaria genética que podría estar implicada en la producción de nuevos compuestos bioactivos

Phylogenomic analyses of the genus Pseudomonas lead to the rearrangement of several species and the definition of new genera

[EN]Pseudomonas represents a very important bacterial genus that inhabits many environments and plays either prejudicial or beneficial roles for higher hosts. However, there are many Pseudomonas species which are too divergent to the rest of the genus. This may interfere in the correct development of biological and ecological studies in which Pseudomonas are involved. Thus, we aimed to study the correct taxonomic placement of Pseudomonas species. Based on the study of their genomes and some evolutionary-based methodologies, we suggest the description of three new genera (Denitrificimonas, Parapseudomonas and Neopseudomonas) and many reclassifications of species previously included in Pseudomonas

Selection of the root endophyte Pseudomonas brassicacearum CDVBN10 as plant growth promoter for Brassica napus L. crops

[EN]Rapeseed (Brassica napus L.) is an important crop worldwide, due to its multiple uses, such as a human food, animal feed and a bioenergetic crop. Traditionally, its cultivation is based on the use of chemical fertilizers, known to lead to several negative e ects on human health and the environment. Plant growth-promoting bacteria may be used to reduce the need for chemical fertilizers, but e cient bacteria in controlled conditions frequently fail when applied to the fields. Bacterial endophytes, protected from the rhizospheric competitors and extreme environmental conditions, could overcome those problems and successfully promote the crops under field conditions. Here, we present a screening process among rapeseed bacterial endophytes to search for an e cient bacterial strain, which could be developed as an inoculant to biofertilize rapeseed crops. Based on in vitro, in planta, and in silico tests, we selected the strain Pseudomonas brassicacearum CDVBN10 as a promising candidate; this strain produces siderophores, solubilizes P, synthesizes cellulose and promotes plant height in 5 and 15 days-post-inoculation seedlings. The inoculation of strain CDVBN10 in a field trial with no addition of fertilizers showed significant improvements in pod numbers, pod dry weight and shoot dry weight. In addition, metagenome analysis of root endophytic bacterial communities of plants from this field trial indicated no alteration of the plant root bacterial microbiome; considering that the root microbiome plays an important role in plant fitness and development, we suggest this maintenance of the plant and its bacterial microbiome homeostasis as a positive result. Thus, Pseudomonas brassicacearum CDVBN10 seems to be a good biofertilizer to improve canola crops with no addition of chemical fertilizers; this the first study in which a plant growth-promoting (PGP) inoculant specifically designed for rapeseed crops significantly improves this crop’s yields in field conditions

Empleo de Instagram para la enseñanza y aprendizaje de la Microbiología

Memoria ID-0198. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2017-2018

Creación de micro-vídeos para su distribución por redes sociales y una pagina web específica como estrategia de enseñanza y aprendizaje en el ámbito de la Microbiología

Memoria ID-183. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2018-2019

EducaFarma 7.0

Memoria ID-013. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2018-2019

EducaFarma 9.0

Memoria ID-020 Ayudas de la Universidad de Salamanca para la innovación docente, curso 2020-2021

Global Map of Specialized Metabolites Encoded in Prokaryotic Plasmids

ABSTRACT Plasmids are the main mobile elements responsible for horizontal gene transfer (HGT) in microorganisms. These replicons extend the metabolic spectrum of their host cells by carrying functional genes. However, it is still unknown to what extent plasmids carry biosynthetic gene clusters (BGCs) related to the production of secondary or specialized metabolites (SMs). Here, we analyzed 9,183 microbial plasmids to unveil their potential to produce SMs, finding a large diversity of cryptic BGCs in a few varieties of prokaryotic host taxa. Some of these plasmids harbored 15 or more BGCs, and many others were exclusively dedicated to mobilizing BGCs. We found an occurrence pattern of BGCs within groups of homologous plasmids shared by a common taxon, mainly in host-associated microbes (e.g., Rhizobiales, Enterobacteriaceae members). Our results add to the knowledge of the ecological functions and potential industrial uses of plasmids and shed light on the dynamics and evolution of SMs in prokaryotes. IMPORTANCE Plasmids are mobile DNA elements that can be shared among microbial cells, and they are useful for bringing to fruition some microbial ecological traits. However, it is not known to what extent plasmids harbor genes related to the production of specialized/secondary metabolites (SMs). In microbes, these metabolites are frequently useful for defense purposes, signaling, etc. In addition, these molecules usually have biotechnological and clinical applications. Here, we analyzed the content, dynamics, and evolution of genes related to the production of SMs in >9,000 microbial plasmids. Our results confirm that some plasmids act as a reservoir of SMs. We also found that some families of biosynthetic gene clusters are exclusively present in some groups of plasmids shared among closely related microbes. Host-associated bacteria (e.g., plant and human microbes) harbor the majority of specialized metabolites encoded in plasmids. These results provide new knowledge about microbial ecological traits and might enable the discovery of novel metabolites