A three-species synthetic community model whose rapid response to antagonism allows the study of higher-order dynamics and emergent properties in minutes

Microbial communities can be considered complex adaptive systems. Understanding how these systems arise from different components and how the dynamics of microbial interactions allow for species coexistence are fundamental questions in ecology. To address these questions, we built a three-species synthetic community, called BARS (Bacillota A + S + R). Each species in this community exhibits one of three ecological roles: Antagonistic, Sensitive, or Resistant, assigned in the context of a sediment community. We show that the BARS community reproduces features of complex communities and exhibits higher-order interaction (HOI) dynamics. In paired interactions, the majority of the S species (Sutcliffiella horikoshii 20a) population dies within 5 min when paired with the A species (Bacillus pumilus 145). However, an emergent property appears upon adding the third interactor, as antagonism of species A over S is not observed in the presence of the R species (Bacillus cereus 111). For the paired interaction, within the first 5 min, the surviving population of the S species acquires tolerance to species A, and species A ceases antagonism. This qualitative change reflects endogenous dynamics leading to the expression for tolerance to an antagonistic substance. The stability reached in the triple interaction exhibits a nonlinear response, highly sensitive to the density of the R species. In summary, our HOI model allows the study of the assembly dynamics of a three-species community and evaluating the immediate outcome within a 30 min frame. The BARS has features of a complex system where the paired interactions do not predict the community dynamics. The model is amenable to mechanistic dissection and to modeling how the parts integrate to achieve collective properties

Phylogenetic Distribution and Evolutionary History of Bacterial DEAD-Box Proteins

DEAD-box proteins are found in all domains of life and participate in almost all cellular processes that involve RNA. The presence of DEAD and Helicase_C conserved domains distinguish these proteins. DEAD-box proteins exhibit RNA-dependent ATPase activity in vitro, and several also show RNA helicase activity. In this study, we analyzed the distribution and architecture of DEAD-box proteins among bacterial genomes to gain insight into the evolutionary pathways that have shaped their history. We identified 1,848 unique DEAD-box proteins from 563 bacterial genomes. Bacterial genomes can possess a single copy DEAD-box gene, or up to 12 copies of the gene, such as in Shewanella. The alignment of 1,208 sequences allowed us to perform a robust analysis of the hallmark motifs of DEAD-box proteins and determine the residues that occur at high frequency, some of which were previously overlooked. Bacterial DEAD-box proteins do not generally contain a conserved C-terminal domain, with the exception of some members that possess a DbpA RNA-binding domain (RBD). Phylogenetic analysis showed a separation of DbpA-RBD-containing and DbpA-RBD-lacking sequences and revealed a group of DEAD-box protein genes that expanded mainly in the Proteobacteria. Analysis of DEAD-box proteins from Firmicutes and γ-Proteobacteria, was used to deduce orthologous relationships of the well-studied DEAD-box proteins from Escherichia coli and Bacillus subtilis. These analyses suggest that DbpA-RBD is an ancestral domain that most likely emerged as a specialized domain of the RNA-dependent ATPases. Moreover, these data revealed numerous events of gene family expansion and reduction following speciation

Generación de un autómata celular para la simulación del ensamblaje de comunidades bacterianas termo-resistentes en cuatro ciénegas Coahuila

Ingenierí

Environmentally-driven gene content convergence and the Bacillus phylogeny

Abstract Background Members of the Bacillus genus have been isolated from a variety of environments. However, the relationship between potential metabolism and the niche from which bacteria of this genus have been isolated has not been extensively studied. The existence of a monophyletic aquatic Bacillus group, composed of members isolated from both marine and fresh water has been proposed. Here, we present a phylogenetic/phylogenomic analysis to investigate the potential relationship between the environment from which group members have been isolated and their evolutionary origin. We also carried out hierarchical clustering based on functional content to test for potential environmental effects on the genetic content of these bacteria. Results The phylogenetic reconstruction showed that Bacillus strains classified as aquatic have evolutionary origins in different lineages. Although we observed the presence of a clade consisting exclusively of aquatic Bacillus, it is not comprised of the same strains previously reported. In contrast to phylogeny, clustering based on the functional categories of the encoded proteomes resulted in groups more compatible with the environments from which the organisms were isolated. This evidence suggests a detectable environmental influence on bacterial genetic content, despite their different evolutionary origins. Conclusion Our results suggest that aquatic Bacillus species have polyphyletic origins, but exhibit convergence at the gene content level

GENERACIÓN DE UN AUTÓMATA CELULAR PARA LA SIMULACIÓN DEL ENSAMBLAJE DE COMUNIDADES BACTERIANAS TERMO-RESISTENTES DE CUATRO CIÉNEGAS COAHUILA.

El espacio en cada celda es el mínimo para que una única ‘célula’ lo ocupe. . El lapso de tiempo entre una iteración y la próxima es el mínimo para que ocurra un único evento

Effectiveness of carboxylic acids from Pichia membranifaciens against coffee rust

ABSTRACT Coffee rust is a fungal disease that has affected every coffee-producing region in the world. Given that the effectivity of the protectant and systemic fungicides applied routinely to control the spread of the causative agent of the disease (Hemileia vastatrix) has gradually diminished, besides are harmful to mammals and ecosystems, the objective of this work was to search for a mixture of harmless natural compounds with the potential to be applied in the field. So, a yeast strain producing a battery of long-chain carboxylic acids (CA) with fungicide properties was isolated from soil of coffee crop and identified as Pichia membranifaciens by ITS sequencing. Culture conditions of the yeast were optimized and the CA in the solution were characterized by Gas Chromatography-Mass Spectrometry (GC-MS) as ethyl formate (55.5 g L-1), octadecenoic acid (3.5 g L-1), propionic acid (7.2 g L-1), 3-(octadecanoyl)-propionic acid (7.2 g L-1) and methyl acetate (8.4 g L-1). Randomized field studies were conducted in three different locations in Chiapas, México. Five treatments were tested including three concentrations of the CA solution (389, 584 and 778 ppm) and copper oxychloride (5 000 ppm) as conventional control. The initial coffee rust incidence averages varied between sites: Maravillas (3-9%), Santo Domingo (10-16%) and Búcaro (16-22%). The treatments of CA solution proved to be effective at slowing down the progress of the rust disease even for the sites where initial incidence was high. Likewise, the CA solution reduced the viability of H. vastatrix spores, as assessed by fluorescence microscopy

Ecos de la academia: Revista de la Facultad de Educación, Ciencia y Tecnología - FECYT Nro 13

Ecos de la academia, Revista de la Facultad de Educación Ciencia y Tecnología es una publicación científica de la Universidad Técnica del Norte, con revisión por pares a doble ciego que publica artículos en idioma español, quichua, portugués e inglés. Se edita con una frecuencia semestral con dos números por año.En ella se divulgan trabajos originales e inéditos generados por los investigadores, docentes y estudiantes de la FECYT, y contribuciones de profesionales de instituciones docentes e investigativas dentro y fuera del país, con calidad, originalidad y relevancia en las áreas de ciencias sociales y tecnología aplicada.Interacción social entre los niños y niñas con necesidades educativas especiales y sus pares: Una revisión narrativa. La afectividad como recurso docente en el proceso de enseñanza-aprendizaje. Perfil del Community Manager de las Instituciones de Educación Superior. Caso de estudio Imbabura, Ecuador. La ética en la función pública. Efectos del mindfulness en preescolares con problemas de comportamiento. Altas capacidades: qué conocen los docentes sobre este alumnado. Desarrollo del proceso lecto-escritor en niños con discapacidad intelectual leve y moderada. Enrique Ayala Mora. Mentiras, medias verdades y polémicas de la historia

La administración pública y el gobierno en México

El texto que aquí se presenta, permite al lector reconocer distintas problemáticas de las administraciones públicas en diferentes vertientes, así como reconocer diagnósticos y alternativas de solución, acordes a la problemática planteada.El gobierno se materializa a través de la Administración Pública, opera por medio de dependencias y entidades adscritas al Poder Ejecutivo. Sus principales actividades están relacionadas con la planeación, la organización, la administración de recursos humanos, la dirección y el control. A partir de este planteamiento inicial, el libro que aquí se presenta La Administración Pública y el gobierno en México: desempeño y procesos gubernamentales pretende aportar al estudio de las administraciones públicas, a través del análisis del desempeño de los gobiernos, tanto en el ámbito federal, estatal y municipal