Primer caso descrito en España de infección por Wohlfahrtiimonas chitiniclastica / First case of infection by Wohlfahrtiimonas chitiniclastica described in Spain

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Primer caso de sepsis por Ignatzschineria en España asociada a miasis. Descripción de un caso y revisión de la literatura / First case of sepsis by Ignatzschineria in Spain associated with myiasis. Description of a case and review of the literatura

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Bacterial isolates from the bryozoan Membranipora membranacea: influence of culture media on isolation and antimicrobial activity

From specimens of the bryozoan Membranipora membranacea collected in the Baltic Sea, bacteria were isolated on four different media, which significantly increased the diversity of the isolated groups. All isolates were classified according to 16S rRNA gene sequence analysis and tested for antimicrobial properties using a panel of five indicator strains and six different media. Each medium featured a unique set of isolated phylotypes, and a phylogenetically diverse collection of isolates was obtained. A total of 96 isolates were assigned to 49 phylotypes and 29 genera. Only one-third of the members of these genera had been isolated previously from comparable sources. The isolates were affiliated with Alpha- and Gammaproteobacteria, Bacilli, and Actinobacteria. A comparable large portion of up to 22 isolates, i.e., 15 phylotypes, probably represent new species. Likewise, 47 isolates (approximately 50%) displayed antibiotic activities, mostly against grampositive indicator strains. Of the active strains, 63.8 % had antibiotic traits only on one or two of the growth media, whereas only 12.7 % inhibited growth on five or all six media. The application of six different media for antimicrobial testing resulted in twice the number of positive hits as obtained with only a single medium. The use of different media for the isolation of bacteria as well as the variation of media considered suitable for the production of antibiotic substances significantly enhanced both the number of isolates obtained and the proportion of antibiotic active cultures. Thus the approach described herein offers an improved strategy in the search for new antibiotic compounds (AU)

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Aislamiento de cepas del género Halomonas con interés biotecnológico en Rambla Salada (Murcia) / Isolaton of strains of the genus Halomonas with biotechnologycal interest from Rambla Salada (Murcia)

El género Halomonas es uno de los taxones bacterianos más representativos dentro de las bacterias halófilas moderadas. Se encuentra incluido en el Phyllum Proteobacteria, clase Gamma-Proteobacteria, familia Halomonadaceae1. Son en su mayoría de bacterias halófilas moderadas, con un requerimiento de NaCl para su óptimo crecimiento que oscila entre un 3-15% (p/v). Las especies de esta familia han demostrado ser un grupo de microorganismos extremófilos con un gran potencial biotecnológico, por la producción de solutos compatibles que les confiere capacidad para estabilizar y proteger enzimas así como aplicaciones en tecnología enzimática, en la industria cosmética y dermofarmacia, medicina y agricultura. Estas especies son capaces de producir también compuestos extracelulares como exopolisacáridos y enzimas extracelulares. Los primeros tienen gran interés industrial debido a sus propiedades viscosizantes, estabilizantes, emulgentes y formadoras de geles. Nuestro grupo de investigación a lo largo de estos años ha caracterizado una decena de estos polímeros destacando los de H. eurihalina y H. maura por sus propiedades viscosizantes y emulgentes 2,3 y los de H. stenophila por sus propiedades antitumorales 4. En cuanto a las enzimas extracelulares, tales como lipasas y amilasas, se mantienen estables en un amplio rango de concentraciones salinas y proporcionan así nuevas posibilidades en los procesos biocatalíticos. Otras aplicaciones biotecnológicas son la producción de polihidroxialcanoatos así como la degradación de compuestos tóxicos. Debido al gran interés biotecnológico de las bacterias halófilas moderadas, nuestro grupo de investigación lleva a cabo un estudio de biodiversidad de microorganismos halófilos en Rambla Salada (Murcia) con el fin de aislar nuevas especies de Halomonas productoras de compuestos de aplicación industrial y/o biotecnológica(AU)

Se han realizado cuatro muestreos durante dos años en Rambla Salada (Murcia, España). Las muestras han sido procesadas mediante las técnicas de microbiología clásicas y las bacterias aisladas han sido caracterizadas fenotípica y filogenéticamente. Las cepas pertenecientes al género Halomonas se sembraron en los medios adecuados para estudiar cada una de las funciones biológicas, y se seleccionaron aquellas cepas que dieron una actividad positiva. Se han aislado 164 cepas del género Halomonas, algunas de ellas con actividad lipasa, proteinasa y/odexosirribonucleasa y casi todas son productoras de exopolisacaridos. La presencia de estas cepas conactividad positiva para determinadas funciones biológicas con interés industrial y biotecnológico ponen de manifiesto la necesidad de seguir investigando en este sentido(AU)

The genus Halomonas is one of the most representative taxa amongst the moderately halophilicbacteria. This genus is included into the family Halomonadaceae, class Gamma-Proteobacteria, Phyllum Proteobacteria1. It requires NaCl concentrations 3-15% w/v for optimum growth. Halomonas species have aroused interest amongst biotechnologists because of their ability to accumulate organic compatible solutes which provide stability and protection of enzymes and other molecules and have interest in enzymatic technology, cosmetic, medicine and agriculture. They also produce extracellular compounds, such as exoenzymes and exopolysaccharides (EPS). The extracellular enzymes, such as lipase and amylase, are stable within a wide salt concentration range; this property is important in biocatalytic processes. Other biotechnological applications of the Halomonas species are the production of polyhydroxyalkanoates and the degradation of aromatic compounds. The halophilic EPS are commercially valuable products because of their biotechnology applications as viscosifying, stabilizers and gelling agents. Our research group has characterized to date tenexopolysaccharides-producing halophilic species. Two of them, H. eurihalina and H. maura produce polymers with viscosifying and emulsifying properties 2,3 and H. stenophila synthesizes and EPS with antitumoral properties 4. Isolate new species of the genus Halomonas with industrial and/or medical applications from Rambla Salada (Murcia, Spain)(AU)

Samples of saline soils, sediments and waters were taken periodically from Rambla Salada (Murcia, Spain) along two years. The samples were processed by classical methods and the isolated strains were identified by mean of phenotypic and phylogenetic techniques. The species belonging to the genus Halomonas were analyzed in order to find compounds of biotechnological interest. We have isolated 164 strains of the genus Halomonas. Some of them have lipases protease and/ordeoxyribonuclease activities and most of them are exopolysaccharide-producing bacteria. The results presented in this work show that extreme environments, such as Rambla Salada, constitute anunexplorable resource of discovering new bacteria and biomolecules(AU)

Massive presence of insertion sequences in the genome of SOPE, the primary endosymbiont of the rice weevil Sitophilus oryzae

Bacteria that establish an obligate intracellular relationship with eukaryotic hosts undergo an evolutionary genomic reductive process. Recent studies have shown an increase in the number of mobile elements in the first stage of the adaptive process towards intracellular life, although these elements are absent in ancient endosymbionts. Here, the genome of SOPE, the obligate mutualistic endosymbiont of rice weevils, was used as a model to analyze the initial events that occur after symbiotic integration. During the first phases of the SOPE genome project, four different types of insertion sequence (IS) elements, belonging to well-characterized IS families from gamma-proteobacteria, were identified. In the present study, these elements, which may represent more than 20% of the complete genome, were completely characterized; their relevance as a source of gene inactivation, chromosomal rearrangements, and as participants in the genome reductive process are discussed herein (AU)

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Polygenic analysis of ammonia-oxidizing bacteria using 16S rDNA, amoA, and amoB genes / Análisis poligénico de cepas de bacterias oxidadoras de amoníaco por medio de los genes 16S rDNA, amoA y amoB

Finding a unique molecular marker capable of quickly providing rigorous and useful phylogenetic information would facilitate assessing the diversity of ammonia-oxidizing bacteria in environmental samples. Since only one of several available markers can be used at a time in these kinds of studies, the 16S rDNA, amoA and amoB genes were evaluated individually and then compared in order to identify the one that best fits the information provided by the composite dataset. Distance-based neighbor-joining and maximum parsimony trees generated using the sequences of the three mentioned genes were analyzed with respect to the combined polygenic trees. Maximum parsimony trees were found to be more accurate than distance-based ones, and the polygenic topology was shown to best fit the information contained in the sequences. However, the taxonomic and phylogenetic information provided by the three markers separately was also valid. Therefore, either of the functional markers (amoA or amoB) can be used to trace ammonia oxidizers in environmental studies in which only one gene can be targeted (AU)

Encontrar un marcador molecular único capaz de proporcionar rápidamente información filogenética rigurosa y útil facilitaría evaluación de la diversidad de las bacterias oxidadoras de amoníaco en muestras ambientales. En esta clase de estudios no se puede utilizar simultáneamente más que uno de los marcadores disponibles. Los genes 16S rDNA, amoA y amoB se evaluaron individualmente para identificar el que se ajusta mejor a la información proporcionada por el conjunto de datos de los tres genes. Se compararon los árboles de Neighbor-Joining, basados en las distancias, y los árboles de máxima parsimonia basados en las secuencias conocidas de los tres genes mencionados, y se analizaron en relación con los árboles poligénicos construidos con la información combinada proporcionada por los tres genes. Los árboles de máxima parsimonia resultaron más fieles que los basados en las distancias, y la topología poligénica era la que mejor se ajustaba a la información contenida en las secuencias. Sin embargo, la información taxonómica y filogenética proporcionada por los tres marcadores por separado también resultó válida. Por tanto, cualquiera de los dos marcadores funcionales (amoA o amoB) se puede utilizar para detectar los oxidantes del amoníaco en estudios ambientales en los que solamente puede usarse un gen (AU)