Publications

3886

Abstract Sil.va.ni.grel'la. N.L. fem. dim. n. Silvanigrella named after Silva nigra the Latin geographic name of the Schwarzwald (Black Forest) mountains located in the south‐west of Germany. Proteobacteria / Oligoflexia / Silvanigrellales / Silvanigrellaceae / Silvanigrella The genus Silvanigrella accommodates heterotrophic freshwater bacteria isolated from the water column of circumneutral or slightly acidic (pH 5–7) lakes and ponds with low ion concentrations (conductivity < 30 μS/cm). So far, only the two species Silvanigrella aquatica and Silvanigrella paludirubra have been described. Cells of the type strains have in common red pigmentation, motility, and pleomorphic morphology. In both species, the cell morphology ranges from rod‐shaped cells to filamentous forms, the cell size is variable in length and width. The type strain of S. aquatica in addition forms, densely coiled spirals. The type strains of both species grow at temperatures above 30°C, but only the type strain of S. paludirubra grows at temperatures below 10°C. Growth occurred up to supplementary NaCl concentrations of 1.0–1.1% (w/v). Both type strains utilized various organic substrates including carbohydrates, amino acids, and short‐chain fatty acids; however, the substrate spectra of the two strains differed. The most abundant fatty acid was iso‐C 15:0 for both type strains, contributing 33% to the total fatty acid content. The major respiratory quinone of S. paludirubra is menaquinone MK‐8, while the quinones of S. aquatica remained unidentified. The type strains of S. aquatica and S. paludirubra were both characterized by medium‐sized genomes (3.5 and 3.9 Mb, respectively) with low G + C content (32.6 and 29.3 mol%, respectively). DNA G + C content (mol%) : 29–33 (genome sequencing). Type species : Silvanigrella aquatica Hahn et al. 2017 VP .

La papa Solanum tuberosum L pertenece a la familia de las solanáceas, es el cuarto cultivo sembrado en más de 100 países incluyendo Nicaragua, en este país existe un consumo por persona de hasta unos 8 kg anuales, la papa se cultiva en Nicaragua entre 800 a 1 200 hectáreas y se obtiene una producción que representa de 35 % a 40 % de la demanda nacional. El objetivo del presente estudio fue determinar la fluctuación poblacional de  Bactericera cockerelli e incidencia de punta morada (Candidatus liberibacter, Solanacearum) en lotes comerciales de papa en el municipio de Estelí entre los meses de enero a noviembre de 2014,  la toma de datos se realizó en lotes de papa en las localidades de Miraflor y El Tisey, los lotes fueron seleccionados con similitud en condiciones climáticas y de manejo del cultivo, en cada lote seleccionado se colocaron trampas amarillas con pegamento para la captura de adultos de B. cockerelli, de igual manera se realizaron muestreos aleatorios en 100 plantas por lote para medir la fluctuación poblacional de ninfas y adultos del vector, así como para medir la incidencia de síntomas similares a Candidatus liberibacter, solanacearum  de las cuales se seleccionaron cinco plantas para análisis y detección del patógeno a través de la técnica de PCR en el Centro Nacional de Diagnostico Fitosanitario del IPSA.  Los resultados indican que el insecto estuvo presente desde el inicio del estudio siendo las mayores capturas en los meses febrero a mayo; julio, agosto y octubre con 0.84 insectos promedio por trampa, de igual manera los meses de marzo, abril, julio y octubre fueron donde se expresaron más plantas con síntomas de 3 al 4% incidencia, así mismo de las muestras tomadas solamente el 20% resultó positivas a la enfermedad coincidiendo con baja poblaciones del insecto vector.

Citrus production is facing an unprecedented problem because of huanglongbing (HLB) disease. Presently, no effective HLB-easing method is available when citrus becomes infected. Guanosine 5′-monophosphate synthetase (GMPS) is a key protein in the de novo synthesis of guanine nucleotides. GMPS is used as an attractive target for developing agents that are effective against the patogen infection. In this research, homology modeling, structure-based virtual screening, and molecular docking were used to discover the new inhibitors against CLas GMPS. Enzyme assay showed that folic acid and AZD1152 showed high inhibition at micromole concentrations, with AZD1152 being the most potent molecule. The inhibition constant (Ki) value of folic acid and AZD1152 was 51.98 µM and 4.05 µM, respectively. These results suggested that folic acid and AZD1152 could be considered as promising candidates for the development of CLas agents.

AbstractAsgardarchaeota have been proposed as the closest living relatives to eukaryotes, and a total of 72 metagenome-assembled genomes (MAGs) representing six primary lineages in this archaeal phylum have thus far been described. These organisms are predicted to be fermentative heterotrophs contributing to carbon cycling in sediment ecosystems. Here, we double the genomic catalogue of Asgardarchaeota by obtaining 71 MAGs from a range of habitats around the globe, including the deep subsurface, brackish shallow lakes, and geothermal spring sediments. Phylogenomic inferences followed by taxonomic rank normalisation confirmed previously established Asgardarchaeota classes and revealed four additional lineages, two of which were consistently recovered as monophyletic classes. We therefore propose the names Candidatus Sifarchaeia class nov. and Ca. Jordarchaeia class nov., derived from the gods Sif and Jord in Norse mythology. Metabolic inference suggests that both classes represent hetero-organotrophic acetogens, which also have the ability to utilise methyl groups such as methylated amines, with acetate as the probable end product in remnants of a methanogen-derived core metabolism. This inferred mode of energy conservation is predicted to be enhanced by genetic code expansions, i.e., stop codon recoding, allowing the incorporation of the rare 21st and 22nd amino acids selenocysteine (Sec) and pyrrolysine (Pyl). We found Sec recoding in Jordarchaeia and all other Asgardarchaeota classes, which likely benefit from increased catalytic activities of Sec-containing enzymes. Pyl recoding, on the other hand, is restricted to Sifarchaeia in the Asgardarchaeota, making it the first reported non-methanogenic archaeal lineage with an inferred complete Pyl machinery, likely providing members of this class with an efficient mechanism for methylamine utilisation. Furthermore, we identified enzymes for the biosynthesis of ester-type lipids, characteristic of bacteria and eukaryotes, in both newly described classes, supporting the hypothesis that mixed ether-ester lipids are a shared feature among Asgardarchaeota.