Extracellular beta-Glucosidase production by marine Aspergillus sydowii BTMFS 55

The beta-glucosidase enzyme purified from the marine fungus, Aspergillus sydowii BTMFS 55 showed a good yield of enzyme production under solid state fermentation. The statistical optimization of the media components revealed that moisture content, concentration of peptone and inoculum are the major parameters which supported the maximal enzyme production. The purified enzyme showed low pH activity and stability, glucose tolerance and activation by ethanol. It could produce ethanol from wheat bran and rice straw by simultaneous saccharification and fermentation with yeast.The glucosidase purified from Aspergillus sydowii BTMFS 55 shows great potential for several biotechnological applications such as the production of bio-ethanol from agricultural biomass and improvement in the aromatic character of wines and fruit juices through the hydrolysis of flavour glucosidic precursors. There is immense scope for the application of this marine fungus in the biofuel production besides in other industries provided further studies are pursued in exploiting this enzyme and the organism particularly scale up studies with respect to application. There is also ample scope for cloning of the gene encoding beta-glucosidase in domesticated hosts such as Pichia pastoris or S. cerevisiae that can produce ethanol directly from cellulosic biomass.

Extracellular β-glucosidase Production by a Marine Aspergillus sydowii BTMFS 55 under Solid State Fermentation Using Statistical Experimental Design

A potential fungal strain producing extracellular β-glucosidase enzyme was isolated from sea water and identified as ^ëéÉêJ Öáääìë=ëóÇçïáá BTMFS 55 by a molecular approach based on 28S rDNA sequence homology which showed 93% identity with already reported sequences of ^ëéÉêÖáääìë=ëóÇçïáá in the GenBank. A sequential optimization strategy was used to enhance the production of β-glucosidase under solid state fermentation (SSF) with wheat bran (WB) as the growth medium. The two-level Plackett-Burman (PB) design was implemented to screen medium components that influence β-glucosidase production and among the 11 variables, moisture content, inoculums, and peptone were identified as the most significant factors for β-glucosidase production. The enzyme was purified by (NH4)2SO4 precipitation followed by ion exchange chromatography on DEAE sepharose. The enzyme was a monomeric protein with a molecular weight of ~95 kDa as determined by SDS-PAGE. It was optimally active at pH 5.0 and 50°C. It showed high affinity towards éNPG and enzyme has a hã and sã~ñ of 0.67 mM and 83.3 U/mL, respectively. The enzyme was tolerant to glucose inhibition with a há of 17 mM. Low concentration of alcohols (10%), especially ethanol, could activate the enzyme. A considerable level of ethanol could produce from wheat bran and rice straw after 48 and 24 h, respectively, with the help of p~ÅÅÜ~êçãóÅÉë=ÅÉêÉîáëá~É in presence of cellulase and the purified β-glucosidase of ^ëéÉêÖáääìë=ëóÇçïáá BTMFS 55.

1.55 µm High-Speed QDs Lasers for Optical Telecommunication Applications

In this work investigation of the QDs formation and the fabrication of QD based semiconductor lasers for telecom applications are presented. InAs QDs grown on AlGaInAs lattice matched to InP substrates are used to fabricate lasers operating at 1.55 µm, which is the central wavelength for far distance data transmission. This wavelength is used due to its minimum attenuation in standard glass fibers. The incorporation of QDs in this material system is more complicated in comparison to InAs QDs in the GaAs system. Due to smaller lattice mismatch the formation of circular QDs, elongated QDs and quantum wires is possible. The influence of the different growth conditions, such as the growth temperature, beam equivalent pressure, amount of deposited material on the formation of the QDs is investigated. It was already demonstrated that the formation process of QDs can be changed by the arsenic species. The formation of more round shaped QDs was observed during the growth of QDs with As2, while for As4 dash-like QDs. In this work only As2 was used for the QD growth. Different growth parameters were investigated to optimize the optical properties, like photoluminescence linewidth, and to implement those QD ensembles into laser structures as active medium. By the implementation of those QDs into laser structures a full width at half maximum (FWHM) of 30 meV was achieved. Another part of the research includes the investigation of the influence of the layer design of lasers on its lasing properties. QD lasers were demonstrated with a modal gain of more than 10 cm-1 per QD layer. Another achievement is the large signal modulation with a maximum data rate of 15 Gbit/s. The implementation of optimized QDs in the laser structure allows to increase the modal gain up to 12 cm-1 per QD layer. A reduction of the waveguide layer thickness leads to a shorter transport time of the carriers into the active region and as a result a data rate up to 22 Gbit/s was achieved, which is so far the highest digital modulation rate obtained with any 1.55 µm QD laser. The implementation of etch stop layers into the laser structure provide the possibility to fabricate feedback gratings with well defined geometries for the realization of DFB lasers. These DFB lasers were fabricated by using a combination of dry and wet etching. Single mode operation at 1.55 µm with a high side mode suppression ratio of 50 dB was achieved.

Enganchados al saber : estudiar en la universidad a partir de los 55 años.

Se trata de un reportaje en el que se exponen las razones de un grupo de personas mayores de 55 años por las que, al término de su vida laboral, se ha matriculado en la Universitat Jaume I de Castelló de la Plana, con el fin de realizar nuevos estudios, La oferta educativa de esta universidad, que cuenta con un titulo universitario propio y unas enseñanzazas divididas en dos ciclos, ha sido considerada por la Unión Europea como un ejemplo de buenas prácticas.

Influencia de la natación sobre el bienestar psicológico en mujeres mayores de 55 años.

Resumen tomado de la publicación

Luther and the german Reformation, 1517-55.

Su contenido se adapta a las especificaciones AS de 2008 para OCR y Edexcel. Se examinan los antecedentes de la Reforma alemana y los factores que condujeron a ella, también se analizan las ideas y la influencia de Lutero, la difusión de estas ideas dentro y fuera de Alemania y el contexto político y religioso que originó estos cambios. Se destacan fechas clave, términos y temas e incluye perfiles biográficos, resúmenes esquemáticos, fuentes literarias y síntesis de los principales debates historiográficos.

The German reformation, 1517-55.

Ofrece una guía práctica para enseñar el tema a los estudiantes del nivel AS para la especificación OCR. El objetivo de este recurso es explicar de forma completa todos los acontecimientos de la Reforma alemana y poner énfasis en el análisis histórico pero, para ello los estudiantes deben tener una comprensión completa de los sucesos, personajes, cuestiones y controversias más relevantes de la época.

Ley de 17 de julio de 1946 por la que se conceden cuatro suplementos de crédito, importantes de 55.000.000 de pesetas, al Ministerio de Educación Nacional para continuación de obras e iniciación de otras nuevas, afectas a la Ciudad Universitaria y Plan Nacional de Cultura.

A través de esta Ley se concedían suplementos de crédito destinados a Educación. Las partidas destinatarias eran: 'gastos diversos', 'auxilios, subvenciones y subsidios', 'Dirección General de Enseñanza Universitaria', 'Universidades' y 'Junta de la Ciudad Universitaria de Madrid'.