Invertase from a Candida stellata strain isolated from grape: production and physico-chemical characterization

Invertases are enzymes which hydrolyze the sucrose and are widely employed in food and pharmaceutical industries. In this work, the screening of autochthonous grape yeasts from Brazil was carried out in order to investigate their invertase production potential. Yeasts belonging to Saccharomyces, Hanseniaspora, Sporidiobolus, Issatchenkia, Candida, Cryptococcus and Pichia genera were analyzed by submerged fermentation (SbmF) using sucrose as substrate. Among them, Candida stellata strain (N5 strain) was selected as the best producer (10.6 U/ml after 48 hours of SbmF). This invertase showed optimal activity at pH 3.0 and 55°C, demonstrating appropriate characters for application in several industrial processes, which includes high temperatures and acid pHs. In addition, this invertase extract presented tolerance to low concentrations of ethanol, suggesting that it could also be suitable for application at the beginning of alcoholic fermentation. These data provide promising prospects of the use of this new invertase in food and ethanol industry.

Leuconostoc mesenteroides SJRP55: a potential probiotic strain isolated from Brazilian water buffalo mozzarella cheese

The probiotic potential of Leuconostoc mesenteroides subsp. mesenteroides SJRP55 isolated from water buffalo mozzarella cheese was evaluated. The microorganism presented resistance to stressful conditions that simulated the gastrointestinal tract, and to the best of our knowledge Leuconostoc mesenteroides SJRP55 was the first of this species with the ability to deconjugate bile salts. Tolerance to NaCl was temperature dependent, as well the results obtained by aggregation capacity. The strain presented good adhesion properties, β galactosidase activity, viability in fermented milk during storage, non-active against Streptococcus thermophilus and sensible to most of the tested antibiotics. Some analgesic medications inhibited the growth of the strain. Leuconostoc mesenteroides SJRP55 exhibited in vitro probiotic potential, and it can be better characterized through future in vivo tests. This bacterium presents higher functional properties compared to other studied strains, and therefore it is a potential candidate for the application as a probiotic strain, which could be used by industries in the manufacture of functional milk-based products.

Leuconostoc mesenteroides SJRP55: a bacteriocinogenic strain isolated from Brazilian water buffalo mozzarella cheese

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Mechanical strain induces the production of spheroid mineralized microparticles in the aortic valve through a RhoA/ROCK-dependent mechanism

Calcific aortic valve disease (CAVD) is a chronic disorder characterized by an abnormal mineralization of the leaflets, which is accelerated in bicuspid aortic valve (BAV). It is suspected that mechanical strain may promote/enhance mineralization of the aortic valve. However, the effect of mechanical strain and the involved pathways during mineralization of the aortic valve remains largely unknown. Valve interstitial cells (VICs) were isolated and studied under strain conditions. Human bicuspid aortic valves were examined as a model relevant to increase mechanical strain. Cyclic strain increased mineralization of VICs by several-fold. Scanning electron microscope (SEM) and energy dispersive X-ray (EDX) analyses revealed that mechanical strain promoted the formation of mineralized spheroid microparticles, which coalesced into larger structure at the surface of apoptotic VICs. Apoptosis and mineralization were closely associated with expression of ENPP1. Inhibition of ENPP1 greatly reduced mineralization of VIC cultures. Through several lines of evidence we showed that mechanical strain promoted the export of ENPP1-containing vesicles to the plasma membrane through a RhoA/ROCK pathway. Studies conducted in human BAV revealed the presence of spheroid mineralized structures along with the expression of ENPP1 in areas of high mechanical strain. Mechanical strain promotes the production and accumulation of spheroid mineralized microparticles by VICs, which may represent one important underlying mechanism involved in aortic valve mineralization. RhoA/ROCK-mediated export of ENPP1 to the plasma membrane promotes strain-induced mineralization of VICs.

O Wortmannin reverte a hiporreatividade de aortas à fenilefrina associada à fase final da prenhez de ratas espontaneamente hipertensas (SHR)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Caracterização de osteoblastos diferenciados de células-tronco mesenquimais da medula óssea de ratos espontâneamente hipertensos (SHR)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Bone stress and strain after use of a miniplate for molar protraction and uprighting: a 3-dimensional finite element analysis

The aim of this study was to use the finite element method to evaluate the distribution of stresses and strains on the local bone tissue adjacent to the miniplate used for anchorage of orthodontic forces. Methods: A 3-dimensional model composed of a hemimandible and teeth was constructed using dental computed tomographic images, in which we assembled a miniplate with fixation screws. The uprighting and mesial movements of the mandibular second molar that was anchored with the miniplate were simulated. The miniplate was loaded with horizontal forces of 2, 5, and 15 N. A moment of 11.77 N.mm was also applied. The stress and strain distributions were analyzed, and their correlations with the bone remodeling criteria and miniplate stability were assessed. Results: When orthodontic loads were applied, peak bone strain remained within the range of bone homeostasis (100-1500 mu m strain) with a balance between bone formation and resorption. The maximum deformation was found to be 1035 mu m strain with a force of 5 N. At a force of 15 N, bone resorption was observed in the region of the screws. Conclusions: We observed more stress concentration around the screws than in the cancellous bone. The levels of stress and strain increased when the force was increased but remained within physiologic levels. The anchorage system of miniplate and screws could withstand the orthodontic forces, which did not affect the stability of the miniplate.

Overproduction and properties of lipase by wild strain of Burkholderia lata LBBIO-BL02 using chicken fat

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Load-application devices: a comparative strain gauge analysis

In view of the low loading values commonly employed in dentistry, a load-application device (LAD) was developed as option to the universal testing machine (UTM), using strain gauge analysis. The aim of this study was to develop a load-application device (LAD) and compare the LAD with the UTM apparatus under axial and non-axial loads. An external hexagonal implant was inserted into a polyurethane block and one EsthetiCone abutment was connected to the implant. A plastic prosthetic cylinder was screwed onto the abutment and a conical pattern crown was fabricated using acrylic resin. An impression was made and ten identical standard acrylic resin patterns were obtained from the crown impression, which were cast in nickel-chromium alloy (n=10). Four strain gauges were bonded diametrically around the implant. The specimens were subjected to central (C) and lateral (L) axial loads of 30 kgf, on both devices: G1: LAD/C; G2: LAD/L; G3: UTM/C; G4: UTM/L. The data (με) were statistically analyzed by repeated measures ANOVA and Tukey's test (p<0.05). No statistically significant difference was found between the UTM and LAD devices, regardless of the type of load. It was concluded that the LAD is a reliable alternative, which induces microstrains to implants similar to those obtained with the UTM.

Papel das espécies reativas de oxigênio na hiporreatividade de aortas à fenilefrina observada no final da prenhez de Ratas Espontaneamente Hipertensas (SHR)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Axial loads on implant-supported partial fixed prostheses for external and internal hex connections and machined and plastic copings: strain gauge analysis

The aim of this in vitro study was to use strain gauge (SG) analysis to compare the effects of the implant-abutment joint, the coping, and the location of load on strain distribution in the bone around implants supporting 3-unit fixed partial prostheses. Three external hexagon (EH) implants and 3 internal hexagon (IH) implants were inserted into 2 polyurethane blocks. Microunit abutments were screwed onto their respective implant groups. Machined cobalt-chromium copings and plastic copings were screwed onto the abutments, which received standard wax patterns. The wax patterns were cast in a cobalt-chromium alloy (n = 5): group 1 = EH/machined. group 2 = EH/plastic, group 3 = IH/machined, and group 4 = IH/plastic. Four SGs were bonded onto the surface of the block tangentially to the implants. Each metallic structure was screwed onto the abutments and an axial load of 30 kg was applied at 5 predetermined points. The magnitude of microstrain on each SG was recorded in units of microstrain (mu epsilon). The data were analyzed using 3-factor repeated measures analysis of variance and a Tukey test (alpha = 0.05). The results showed statistically significant differences for the type of implant-abutment joint, loading point, and interaction at the implant-abutment joint/loading point. The IH connection showed higher microstrain values than the EH connection. It was concluded that the type of coping did not interfere in the magnitude of microstrain, but the implant/abutment joint and axial loading location influenced this magnitude.

Strain rates estimated by geodetic observations in the Borborema Province, Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Interaction between recrystallization and strain-induced precipitation in a high Nb- and N-bearing austenitic stainless steel: influence of the interpass time

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Influence of environmental factors in the adherence of an atypical enteropathogenic Escherichia coli strain to epithelial cells

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)