The complete genome sequence of Chromobacterium violaceum reveals remarkable and exploitable bacterial adaptability

Chromobacterium violaceum is one of millions of species of free-living microorganisms that populate the soil and water in the extant areas of tropical biodiversity around the world. Its complete genome sequence reveals (i) extensive alternative pathways for energy generation, (ii) ≈500 ORFs for transport-related proteins, (iii) complex and extensive systems for stress adaptation and motility, and (iv) wide-spread utilization of quorum sensing for control of inducible systems, all of which underpin the versatility and adaptability of the organism. The genome also contains extensive but incomplete arrays of ORFs coding for proteins associated with mammalian pathogenicity, possibly involved in the occasional but often fatal cases of human C. violaceum infection. There is, in addition, a series of previously unknown but important enzymes and secondary metabolites including paraquat-inducible proteins, drug and heavy-metal-resistance proteins, multiple chitinases, and proteins for the detoxification of xenobiotics that may have biotechnological applications

Impacts of the nitrogen application on productivity and nutrients concentrations of the corn-Congo grass intercropping system in the dry season

The corn-grass intercropping system began to be used in the dry season, as it provides increased straw production for the no-tillage system. However, corn and grass are plants demanding in nitrogen. The corn cultivated in the dry season is called out-of-season corn in Brazil. The objective of this study was to evaluate the productivity and nutrients concentrations of out-of-season corn and Congo-grass intercropped in the no-tillage system, as a function of the nitrogen rates applied in sidedressing. The treatments were four nitrogen rates, 0, 30, 60 and 90 kg ha−1. The experimental design was randomised complete blocks with four replicates. The experimental period corresponded to the harvests of 2015 and 2016. There were evaluated: corn grain yield, dry mass production and nutrient concentration in the shoots of the plants intercropped. The evaluations were carried out at the physiological maturity stage of the corn and at the time of desiccation of the grass. Nitrogen increased grain yield and dry mass production of the plants intercropped. Nitrogen maximised the magnesium concentration in out-of-season corn and the nitrogen, calcium, magnesium and sulphur concentrations in Congo grass. Excess nitrogen promoted reduction of the phosphorus in the Corn-Congo grass intercropping system in the dry season

The influence of phosphorus and calcium application rates on the mineral composition of the perennial legume Macrotyloma axillare

The response of legumes to the supply of either phosphorus (P) or calcium (Ca) alone has been extensively investigated but no prior studies have evaluated their combinations in the perennial legume Macrotyloma axillare (Macrotyloma legume). This study assessed the mineral composition of Macrotyloma legume in response to the combined application of P and Ca in an Ultisol. The experiment was conducted in a greenhouse in Nova Odessa city, São Paulo, Brazil. Five rates of P and Ca, respectively, were combined in a 52 incomplete fractional factorial design. Thus, the treatments consisted of 13 P and Ca combination rates (respectively, in mg dm−3): 0‒0, 0‒40, 0‒80, 15‒20, 15‒60, 30‒0, 30‒40, 30‒80, 45‒20, 45‒60, 60‒0, 60‒40 and 60‒80 arranged in a randomised block design with four replications. Mineral composition was evaluated after two harvests (53 d after sowing and 34 d after the first harvest). During the initial growth of the Macrotyloma legume, P × Ca interactions occurred. The P supply antagonistically influenced the nitrogen content. The excess P supply reduced nitrogen accumulation in the shoots and caused a lack of nitrogen in the leaves. The Ca supply synergistically impacted the magnesium content and caused a ‘Viets effect’ in potassium content.Keywords: antagonistic effect, macronutrient status, plant nutrition, sustainable livestock, synergistic effec

The Deposition of a Lectin from <i>Oreochromis niloticus</i> on the Surface of Titanium Dioxide Nanotubes Improved the Cell Adhesion, Proliferation, and Osteogenic Activity of Osteoblast-like Cells

Titanium and its alloys are used as biomaterials for medical and dental applications, due to their mechanical and physical properties. Surface modifications of titanium with bioactive molecules can increase the osseointegration by improving the interface between the bone and implant. In this work, titanium dioxide nanotubes (TiO2NTs) were functionalized with a lectin from the plasma of the fish Oreochromis niloticus aiming to favor the adhesion and proliferation of osteoblast-like cells, improving its biocompatibility. The TiO2NTs were obtained by anodization of titanium and annealed at 400 °C for 3 h. The resulting TiO2NTs were characterized by high-resolution scanning electron microscopy. The successful incorporation of OniL on the surface of TiO2NTs, by spin coating, was demonstrated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIE), and attenuated total reflection-Fourier transform infrared spectrum (ATR-FTIR). Our results showed that TiO2NTs were successfully synthesized in a regular and well-distributed way. The modification of TiO2NTs with OniL favored adhesion, proliferation, and the osteogenic activity of osteoblast-like cells, suggesting its use to improve the quality and biocompatibility of titanium-based biomaterials

Characterization and application of nanostructured films containing Au and TiO2 nanoparticles supported in bacterial cellulose

In the last several years, the use of renewable energy sources has increased; consequently, the number of studies regarding their efficiency has also increased. It is well known that fossil and atomic fuels will not last forever and that their use contributes to environmental pollution. Thus, nanostructured thin films have attracted attention due to numerous applications, including construction of photovoltaic energy generating and photoluminescence materials. Therefore, in this study, we prepared and characterized thin films supported on bacterial cellulose that were produced using the layer-by-layer (LbL) technique. The weak polyelectrolytes, such as poly(allylamine hydrochloride) (PAH) and poly(acrylic acid) (PAA), combined with titanium dioxide (TiO2) and gold nanoparticles (Au NPs) were used to produce flexible devices capable of producing hydrogen gas (H-2) by photocatalysis. The presence of the Au NPs and TiO2 in the films was confirmed using UV-vis spectroscopy, Rutherford backscattering spectrometry, and X-ray diffraction. Scanning electron microscopy was used to evaluate the surface morphology of the films, and the distribution and average size of the Au NPs were analyzed using transmission electron microscopy, which revealed sizes in the nanometer range. Finally, the thin films were analyzed using gas chromatography to evaluate the H-2 production by photocatalysis. Overall, the system with (PAH + TiO2) and PAA solutions at pH = 4.0 in the presence of gold salt that were reduced with ultraviolet light were more efficient due to their greater interactions with the TiO2 during multilayer deposition.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES