Shotgun sequencing was employed to explore the community structure (phylotyping of rRNA genes) and functional potential of Cabernet Sauvignon grape must microbiome. A metagenomic library, representing 92.6 Mb of genetic information, was generated from DNA obtained from Cabernet Sauvignon grape must.. Fungi were identified as the dominant domain (59.5%) followed by Streptophyta (39%). Among the 84 fungal species, 22 were yeasts of various genera. Additionally, grapevine endophytes such as Davidiella sp., Botryotinia fuckeliana, Alternaria sp., and Cladosporium sp. were identified. An unusually high prevalence of Mucor spp. was evidenced. Functional annotation revealed sequences of genes involved in metabolism (35.6%), followed by poorly characterized categories (28.3%), cellular processes and signalling (18.4%), and finally information storage (17.8%). Among the former, glycosidases were abundant followed by glycogen debranching enzyme, 6-phosphofructokinase and trehalose-6-phosphate synthase. Furthermore, the taxonomic analysis of the functional sequence data exhibited the eukaryotic gene pool that predominantly contains sequences derived from Streptophyta (mainly Vitis vinifera) 60% > Ascomycota (32%) > Basidiomycota (5%) > Bacteria (2.5%). Finally, sequences of a variety of hydrolytic enzymes of potential oenological relevance were retrieved, thereby confirming that grape juice is a rich reservoir for valuable biocatalysts that should be explored further.

Abstract Staphylococcus aureus (S. aureus) is a highly versatile Gram-positive bacterium that is carried asymptomatically by up to 30% of healthy people, while being a major cause of healthcare-associated infections, making it a worldwide problem in clinical medicine. The adaptive evolution of S. aureus strains is demonstrated by its remarkable capacity to promptly develop high resistance to multiple antibiotics, thus limiting treatment choice. Nowadays, there is a continuous demand for an alternative to the use of antibiotics for S. aureus infections and a strategy to control the spread or to kill phylogenetically related strains. In this scenario, bacteriocins fit as with a promising and interesting alternative. These molecules are produced by a range of bacteria, defined as ribosomally synthesized peptides with bacteriostatic or bactericidal activity against a wide range of pathogens. This work reviews ascertained the main antibiotic-resistance mechanisms of S. aureus strains and the current, informative content concerning the applicability of the use of bacteriocins overlapping the use of conventional antibiotics in the context of S. aureus infections. Besides, we highlight the possible application of these biomolecules on an industrial scale in future work.

Abstract: Protonated titanate nanotubes (HTiNts) were synthesized using the hydrothermal method, followed by proton exchange with acid. Gold nanoparticles decorated titanate nanotubes (AuHTiNts) were obtained by the reduction of AuCl4- under vigorous stirring with an aqueous solution of HTiNts containing 1 wt% of ascorbic acid. To investigate the surface structural chemistry of the titanate and AuHTiNts, the following characterization methods were used: scanning and transmission electron microscopy, X-ray diffraction, UV-Vis diffuse reflectance spectroscopy, Raman spectroscopy and X-ray photo-electron spectroscopy. The mean internal and external diameters for titanate nanotubes were found to be 5.46 ± 0.08 nm and 8.42 ± 0.03 nm, respectively, whereas the mean diameter of gold nanoparticles was measured to be 9.68 nm ± 0.03 nm. The as-synthesized AuHTiNts was used as photocatalyst in hydrogen production from glycerol as a sacrificial agent. The enhancement in the production of hydrogen, using the heterogeneous AuHTiNts catalysts, can be attributed to the intrinsic catalytic potential of gold as well as its interactions with titanate nanostructure.

Resumo Nanopartículas (NPs) de TiO2 foram sintetizadas por métodos de sol-gel usando dois diferentes precursores, tetraisopropóxido de titânio e oxalato de potássio e titânio (KTO). Os precursores tiveram profunda influência nas propriedades estruturais, morfológicas, dielétricas e magnéticas das NPs de TiO2 sintetizadas, como evidenciado pelos estudos de DRX, FE-MEV, MET, LCR e VSM das amostras sintetizadas. As NPs de TiO2 derivadas de alcóxido apresentaram principalmente fases misturadas de anatásio e rutilo, enquanto que as NPs de TiO2 derivadas de KTO apresentaram fases anatásio e de Magnéli (TinO2n-1). Após tratamento térmico a 550 °C, o tamanho de cristalito das NPs derivadas de KTO foi menor do que o das NPs de TiO2 derivadas de alcóxido. As nanopartículas sintetizadas foram esféricas e aglomeradas com fases anatásio e rutilo em diferentes proporções na microestrutura da amostra de alcóxido. A constante dielétrica das NPs derivadas de KTO foi maior do que a das NPs derivadas de alcóxido. O comportamento diamagnético das NPs derivadas de KTO também foi maior do que o das NPs de TiO2 derivadas de alcóxido.

Abstract TiO2 nanoparticles (NPs) were synthesized by sol-gel methods using two different precursors, titanium tetraisopropoxide and potassium titanium oxalate (KTO). The precursors had a profound influence on the structural, morphological, dielectric and magnetic properties of synthesized TiO2 NPs, as evidenced by the XRD, FE-SEM, TEM, LCR and VSM studies in the synthesized samples. Alkoxide-derived TiO2 NPs contained mostly mixed phases of anatase and rutile, whereas KTO-derived TiO2 NPs contained anatase and Magnéli phases (TinO2n-1). After heat treatment at 550 °C, the crystallite size of KTO-derived NPs was lower than alkoxide-derived TiO2 NPs. The synthesized nanoparticles were spherical and agglomerated having anatase and rutile phases with different proportions in the microstructure of the alkoxide sample. Dielectric constant of the KTO-derived NPs was higher than the alkoxide-derived NPs. Diamagnetic behavior of KTO-derived NPs was also higher than the alkoxide-derived TiO2 NPs.

Natural vinegar is one of the fermented products which has some potentiality with respect to a nutraceutical standpoint. The present study is an optimization of the fermentation conditions for palm juice vinegar production from palm juice (Borassus flabellifer) wine, this biochemical process being aided by Acetobacter aceti (NCIM 2251). The physical parameters of the fermentation conditions such as temperature, pH, and time were investigated by Response Surface Methodology (RSM) with 2³ factorial central composite designs (CCD). The optimum pH, temperature and time were 5.5, 30 °C and 72 hrs for the highest yield of acetic acid (68.12 g / L). The quadratic model equation had a R² value of 0.992. RSM played an important role in elucidating the basic mechanisms in a complex situation, thus providing better process control by maximizing acetic acid production with the respective physical parameters. At the optimized conditions of temperature, pH and time and with the help of mathematical kinetic equations, the Monod specific growth rate ( µ max= 0.021 h-1), maximum Logistic specific growth rate ( µ 'max = 0.027 h-1) and various other kinetic parameters were calculated, which helped in validation of the experimental data. Therefore, the established kinetic models may be applied for the production of natural vinegar by fermentation of low cost palm juice.

In the present study, an attempt is made to propose a new operational technique for weather forecasting at Kolkata (22.53° N, 88.33° E), India, during the pre-monsoon season (March, April and May). The technique is based on fuzzy membership roster method. It can handle inherent non-linearity in a physical phenomenon. To establish the new method, a comparative study is performed between the existing multivariate technique, the linear discriminant analysis and the newly suggested technique based on fuzzy membership roster method. It is interesting to note that for the prediction of weather of next 12 hours based on Radio/Rawin Sonde observation at 1200 UTC of a day, the fuzzy membership roster method is better than the multivariate technique. Both the methods are however almost equally suitable to predict the weather of the next 12 hours based on Radio/ Rawin Sonde observation at 0000 UTC. So, the fuzzy logic based technique, adopted here, is as efficient as the linear statistical rules, but computationally simpler. The degrees of compatibility and the discriminant functions are defined using a training data set for the period 1985-1996 and validated for the period 1997-1999.

En este trabajo se hace un intento para proponer una nueva técnica operacional para la predicción del tiempo en Calcuta (22.53° N, 88.33° E), India, durante la temporada premonzónica (marzo, abril y mayo). La técnica se basa en el método de listado de funciones de pertenencia difusa que maneja la linealidad no inherente de un fenómeno físico. Para establecer este nuevo método se realizó un estudio comparativo entre las técnicas multivariadas existentes, el análisis lineal discriminante y la nueva técnica basada en el método de listado de funciones de pertenencia difusa. Es interesante observar que para la predicción del tiempo a 12 horas con base en las observaciones de la sonda Radio/Rawin de un día, el método de listado de funciones de pertenencia difusa es mejor que las técnicas multivariadas. Sin embargo, ambos métodos son casi igualmente efectivos para predecir el tiempo de las siguientes 12 horas conbase en las observaciones de la sonda Radio/Rawin a las 0000 UTC. Así, la técnica basada en la lógica difusa adoptada aquí es igual de eficiente que las de la estadística lineal pero computacionalmente más sencilla. Los grados de compatibilidad y de funciones discriminantes se definen utilizando un conjunto de datos de entrenamiento para el período 1985-1996 validado para el período 1997-1999.

The two sophisticated applied multivariate techniques, ‘Principal Component Analysis’ and ‘Two-group Linear Discriminant Analysis’ have been applied in the present work to analyze the pre-monsoon weather in Calcutta (India) and hence to forecast the pre-monsoon thunderstorms there. The work has been performed in the following two stages: i) Analysis with 20 thermodynamic and dynamic parameters derived from daily radiosonde data in Calcutta; ii) Analysis with 10 newly formed parameters which are actually the first 10 principal components formed with the 20 original parameters. The study indicates that an index known as ‘Linear Discriminant Function’ (LDF) may be constructed to predict the pre-monsoon weather in Calcutta. Not only that, the study also reveals that if the dimensionalities of the data matrices are reduced, then the accuracy of the results may improve.

En el presente trabajo se aplicaron dos técnicas multivariadas sofisticadas, el “Análisis de componente principal” y el “Análisis lineal discriminante de dos grupos”, para analizar el clima pre-monzónico de Calcuta (India) y predecir las tormentas pre-monzónicas de ese lugar. El trabajo se desarrolló en las siguientes etapas: i) Análisis con 20 parámetros dinámicos y termodinámicos derivados de los datos diarios de la radiosonda de Calcuta, ii) Análisis con 10 parámetros nuevos que son los 10 componentes principales formados con los 20 parámetros originales. El estudio indica que se puede construir un índice conocido como “Función lineal discriminante” (FLD), para predecir el clima pre-monzónico de Calcuta. Además, la investigación revela que si se reducen las dimensionalidades de las matrices de datos, la exactitud de los resultados se mejora.