ABSTRACT
A free-living, nitrogen-fixing, mesophilic and facultative aerobe, designated strain USBA 369T, was isolated from a terrestrial saline spring of the Colombian Andes. The non-sporulating rods (1.5×0.8 µm) with rounded ends stained Gram-negative and were motile by means of lophotrichous flagella. The strain grew optimally at 30 °C, at pH 6.9-7.5 and with 1.5â% (w/v) NaCl. The major fatty acids detected were C18â:â1ω7c and C19â:â0 cyclo ω8c, and the respiratory lipoquinone ubiquinone 10 (Q-10) was present. The genome consisted of 4.65 Mb with a DNA G+C content of 64.3 mol%. A total of 4371 genes were predicted and, of those, 4300 were protein coding genes and 71 were RNA genes. Phylogenetic analysis based on 16S rRNA gene sequence indicated that strain USBA 369T formed a different lineage within the class Alphaproteobacteria, order Rhizobiales, and DNA homology studies with the most closely related genera, Aurantimonas, Aureimonas and Rhizobium (95â% 16S rRNA gene sequence similarity), showed values of <15â%. The phylogenomic analysis provided evidence for clear phylogenetic divergence between strain USBA 369T and the closely related genera. On the basis of the phenotypic, chemotaxonomic and phylogenomic evidence, strain USBA 369T is considered to represent a novel genus and a novel species for which the name Consotaella salsifontis gen. nov., sp. nov. is proposed. The type strain is USBA 369T (=KCTC 22549T=CMPUJ U369T).
Subject(s)
Alphaproteobacteria/classification , Natural Springs/microbiology , Phylogeny , Salinity , Alphaproteobacteria/genetics , Alphaproteobacteria/isolation & purification , Bacterial Typing Techniques , Base Composition , Colombia , DNA, Bacterial/genetics , Fatty Acids/chemistry , Nitrogen Fixation , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Ubiquinone/chemistryABSTRACT
Abstract Using Response Surface Methodology (RSM) we evaluated the culture conditions (nitrogen source, carbon source, pH and agitation rate) that increase the biomass of Acidocellafaalis strain USBA-GBX-505 and therefore enhance the production of its lipolytic enzyme, 505 LIP. RSM results revealed that yeast extract and agitation were key culture factors that increased the growth-associated lipolytic activity by 4.5-fold (from 0.13 U.mg-1 to 0.6 U.mg-1). The 505 LIP lipase was partially purified using size-exclusion chromatography and ion-exchange chromatography. Its molecular weight was >77 kDa. The enzyme shows its optimum catalytic activity at 55 °C and pH 7.5. EDTA, PMSF, 1-butanol and DMSO inhibited enzymatic activity, whereas Tween 20, acetone, glycerol and methanol increased it. Metallic ions are not required for the activity of 505 LIP, and even have an inhibitory effect on the enzyme. This study shows the potential use of A. facilis strain USBA- GBX-505 for the production of a newly identified lipolytic enzyme, 505 LIP, which is stable at moderate temperatures and in the presence of organic solvents. These are important characteristics for the synthesis of many useful products.
Resumen Por medio de la Metodología de Respuesta de Superficie (RSM) evaluamos las condiciones de cultivo (fuente de N, fuente de C, pH y tasa de agitación) que incrementan la biomasa de Acidocella facilis cepa USBA-GBX-505 y, como consecuencia, la producción de su enzima lipolítica, llamada 505 LIP. Los resultados de la RSM revelaron que el extracto de levadura y la agitación fueron factores de cultivo claves, que incrementaron de 4 a 5 veces la actividad lipolítica asociada al crecimiento (de 0.13 U.mg-1 a 0.6 U.mg-1). La lipasa 505 LIP se purificó parcialmente usando cromatografía de exclusión por tamaño y cromatografía de intercambio iónico. Su peso molecular fue > 77 kDa. La enzima muestra su actividad catalítica óptima a 55 °C y pH 7.5. El EDTA, el PMSF, el 1-butanol y el DMSO inhibieron la actividad enzimática, mientras que el Tween 20, la acetona, el glicerol y el metanol la incrementaron. La enzima 505 LIP no requiere iones metálicos para su actividad, e incluso se inhibe en presencia de ellos. Este estudio muestra el uso potencial de A. facilis cepa USBA-GBX-505 para la producción de una nueva enzima lipolítica, 505 LIP, que es estable a temperaturas moderadas y en la presencia de solventes orgánicos. Estas son características importantes en la síntesis de muchos productos útiles.
Resumo Utilizando a Metodologia de Superfície de Resposta (MSR) avaliamos as condições de cultivo (fontes de nitrogénio e carbono, pH e taxa de agitação) que aumentam a biomassa de Acidocella facilis cepa USBA-GBX-505, e, portanto, elevam a produção de sua enzima lipolítica 505 LIP. Os resultados da MSR revelaram que o extrato de levedura e a agitação foram fatores de cultivo chave que permitiram aumentar 4 a 5 vezes a atividade lipolítica associada ao crescimento (de 0,13 U.mg-1 a 0,6 U.mg-1). A lipase 505 LIP foi parcialmente purificada utilizando cromatografia por exclusão de tamanho e cromatografia de intercambio iónico. Seu peso molecular foi > 77 kDa. A enzima mostra sua atividade catalítica ótima a 55 °C e pH 7,5. EDTA, PMSF, 1-butanol e DMSO inibiram a atividade enzimática, enquanto que Tween 20, acetona, glicerol e metanol aumentaram esta atividade. Íons metálicos não são necessários para a atividade da 505 LIP, apresentando inclusive efeito inibitório da enzima. Este estudo demonstra o potencial uso de A. facilis cepa USBA-GBX-505 para a produção de uma nova enzima lipolítica, 505 LIP, a qual é estável a moderadas temperaturas e na presença de solventes orgánicos. Estas características são importantes para a síntese de diversos produtos úteis.
Subject(s)
Chromatography, Ion Exchange/methodsABSTRACT
Introducción. Existe la hipótesis de que las emociones participan del proceso cognitivo de la toma de decisiones guiando la conducta y dotando a la experiencia de una cualidad positiva o negativa que permite la adaptación del individuo al medio social. Método: La muestra estuvo conformada por 81 menores de edad (48 que cumplían con uno o dos criterios del DSM-IV y 33 sin alteraciones de comportamiento). Se utilizó la Escala Muldimensional de la Conducta, el SNAP IV y el Check list para TDC como instrumentos de tamizaje para su selección, posteriormente se realizó la evaluación con la versión computarizada de la IGT (Iowa Gambling Task). Resultados: Se dan diferencias estadísticamente significativas entre el grupo estudio y de comparación para la selección de las barajas desventajosas B durante la ejecución de la tarea. Los menores en riesgo presentaron un desempeño menor para la prueba general de toma de decisiones. Discusión: Los resultados indican la presencia de alteraciones en los procesos de toma de decisiones de los menores que presentan uno o dos criterios clínicos para desarrollar el TDC.
Introduction: There is a hypothesis that proposes that emotions take part in the cognitive process related to decision-making behavior; such processes provide experience of a positive or negative quality that allows the adaptation of a human being to a social background. Methods: There were 81 minors participants (48 qualified with one or two standards of DSM-IV and 33 without conduct disorders). We used Multidimensional Scale of Conduct, SNAP IV, and checklist for CD as screening instruments for its selection, and later we performed the assessment with the online version of IGT (Iowa Gambling Task). Results: A statistically significant difference was present between study and control groups in the selection of unfavorable decks of cards. Those children affected by behavioral disorders presented lower results in the general decision-making test. Conclusions: Results suggest the presence of disorders in decision-making in minors that present one or two clinical criteria to develop CD. This could be due to difficulties in contingency processing for unfavorable decisions, which prevented them from generating somatic states based on the possible future consequences.
