Desert truffle mycorrhizosphere harbors organic acid releasing plant growth-promoting rhizobacteria, essentially during the truffle fruiting season.

Desert truffle is becoming a new crop in semiarid areas. Climatic parameters and the presence of microorganisms influence the host plant physiology and alter desert truffle production. Desert truffle plants present a typical summer deciduous plant phenology divided into four stages: summer dormancy, autumn bud break, winter photosynthetic activity, and spring fruiting. We hypothesize that the bacterial community associated with desert truffle plants will show a seasonal trend linked to their plant growth-promoting rhizobacteria (PGPR) traits. This information will provide us with a better understanding about its potential role in this symbiosis and possible management implementations. Bacteria were isolated from root-adhering soil at the four described seasons. A total of 417 isolated bacteria were phenotypically and biochemically characterized and gathered by molecular analysis into 68 operational taxonomic units (OTUs). They were further characterized for PGPR traits such as indole acetic acid production, siderophore production, calcium phosphate solubilization, and ACCD (1-amino-cyclopropane-1-carboxilatedeaminase) activity. These PGPR traits were used to infer functional PGPR diversity and cultivable bacterial OTU composition at different phenological moments. The different seasons induced shifts in the OTU composition linked to their PGPR traits. Summer was the phenological stage with the lowest microbial diversity and PGPR functions, whereas spring was the most active one. Among the PGPR traits analyzed, P-solubilizing rhizobacteria were harbored in the mycorrhizosphere during desert truffle fruiting in spring.

Beneficial native bacteria improve survival and mycorrhization of desert truffle mycorrhizal plants in nursery conditions.

Sixty-four native bacterial colonies were isolated from mycorrhizal roots of Helianthemum almeriense colonized by Terfezia claveryi, mycorrhizosphere soil, and peridium of T. claveryi to evaluate their effect on mycorrhizal plant production. Based on the phylogenetic analysis of the 16S rDNA partial sequence, 45 different strains from 17 genera were gathered. The largest genera were Pseudomonas (40.8 % of the isolated strains), Bacillus (12.2 % of isolated strains), and Varivorax (8.2 % of isolated strains). All the bacteria were characterized phenotypically and by their plant growth-promoting rhizobacteria (PGPR) traits (auxin and siderophore production, phosphate solubilization, and ACC deaminase activity). Only bacterial combinations with several PGPR traits or Pseudomonas sp. strain 5, which presents three different PGPR traits, had a positive effect on plant survival and growth. Particularly relevant were the bacterial treatments involving auxin release, which significantly increased the root-shoot ratio and mycorrhizal colonization. Moreover, Pseudomonas mandelii strain 29 was able to considerably increase mycorrhizal colonization but not plant growth, and could be considered as mycorrhiza-helper bacteria. Therefore, the mycorrhizal roots, mycorrhizosphere soil, and peridium of desert truffles are environments enriched in bacteria which may be used to increase the survival and mycorrhization in the desert truffle plant production system at a semi-industrial scale.

Hiperparatiroidismos debidos a glándulasparatiroides de localización torácica / Hyperparathyroidism due to thoracic parathyroid glands

Introducción. El objetivo de este estudio es el de revisar nuestra experiencia en el manejo de los hiperparatiroidismos (HPT) debidos a glándulas paratiroides de localización torácica. Pacientes y método. Se han revisado retrospectivamente las historias clínicas y los protocolos operatorios de los pacientes con HPT primario (HPT1) o secundario (HPT2) que precisaron un abordaje torácico para la exéresis de una glándula paratiroides patológica. Se recogieron las variables demográficas, la realización o no de una paratiroidectomía previa, el resultado de las técnicas de imagen, la situación de la glándula, el abordaje realizado, el número de glándulas identificadas y las complicaciones postoperatorias. Resultados. Se han identificado 7 casos de glándula paratiroides torácica que representan un 3 por ciento de las 239 paratiroidectomías (190 por HPT1 y 49 por HPT2) realizadas por nuestro grupo; cinco eran varones y 2 mujeres, con edades comprendidas entre 36 y 67 años. Cuatro pacientes presentaban HPT1 y 3, HPT2. En 6 pacientes con identificación paratiroidea completa, la paratiroides torácica fue supernumeraria. Todos los casos fueron intervenidos con dos técnicas de imagen (TC y Tc-mibi/SPECT) positivas. Se realizaron tres esternotomías medias totales, una esternotomía parcial, dos mediastinotomías anteriores izquierdas y una toracotomía izquierda. Las glándulas patológicas se localizaron en el mediastino anterior (5), sobre el borde izquierdo del cayado aórtico (1) y en la ventana aortopulmonar (1).Conclusiones. El hiperparatiroidismo por glándula patológica torácica es debido a una glándula supernumeraria, se diagnostica a menudo antes de la primera intervención, es más frecuente en el mediastino anterior y puede tratarse de forma selectiva obviando el acceso transesternal (AU)