Solubilization of iron phosphate by free or immobilized spores and pellets of Aspergillus niger

The production of pellets by Aspergillus niger and the FePO 4 (FeP) solubilization through the use of free or immobilized spores and pellets were studied. The media Sabouraud, MS-FeP, MS-K 2HPO 4, Czapek and Malt were used for pellets yield. Enhanced growth and pellets production were found in the Sabouraud and MS-FeP than those produced by the other media. Pellets produced in Sabouraud were larger in size and formed well-defined spheres than those produced in MS-FeP. Pellets amounts varying from 2 to 8 mg mL, -1 were inoculated in the MS-FeP medium. The greatest quantity of solubilized FeP was found when 6 mg of pellets mL, -1 were used. While the free spores were the worst form used for FeP solubilization in culture medium, free pellets allowed for the production of the greatest quantities of soluble phosphate, even after repeated use of the pellets. In the soil, pellets solubilized similar quantities of FeP compared to the immobilized A. niger spores and can be used with advantage since they are easily produced. © 2010 Academic Journals Inc.

Glucose homeostasis in type 1 diabetic rats after acute physical activity

Physical activity is considered an extremely effective therapy in cases of type 1 diabetes (DM-1), as it promotes glucose uptake independent of insulin action. However, there are few studies on the effect of a single session of exercise on glucose uptake in DM-1 (i.e., in the absence of insulin). Therefore, the purpose of this study was to assess the effect of a single exercise session on glucose homeostasis in DM-1 rats. For this purpose, 30 male rats were divided into three groups: sedentary control (SC), sedentary diabetic (SD), and exercise diabetic (ED). DM was induced by administration of alloxan and identified by the value of fasting glucose. The physical activity consisted of a single swimming session at the anaerobic threshold intensity for diabetic rats (3.5% body weight overload) for 30 min. The oral glucose tolerance test (OGTT) was performed immediately after the physical activity. The animals were sacrificed 48 hr after the OGTT, and samples were taken from the blood, liver, gastrocnemius, and mesenteric and subcutaneous adipose tissue. We observed that DM caused significant reduction in body weight. A single session of physical activity did not modify the response to the OGTT or glucose. However, it resulted in increased HDL cholesterol and hepatic glycogen content. These results suggest that, despite not having an effect on glucose homeostasis, acute physical activity performed at anaerobic threshold intensity leads to beneficial changes in the context of type 1 diabetes.

Characterization of a glucose- and solvent-tolerant extracellular tannase from Aspergillus phoenicis

Tannases have attracted wider attention because of their biotechnological potential, especially enzymes from filamentous fungi and other microorganisms. However, the biodiversity of these microorganisms has been poorly explored, and few strains were identified for tannase production and characterization. This article describes the production, purification and characterization of a glucose- and solvent-tolerant extracellular tannase from Aspergillus phoenicis. High enzymatic levels were obtained in Khanna medium containing tannic acid up to 72 h at 30 °C under 100 rpm. The purified enzyme with 65% of carbohydrate content had an apparent native molecular mass of 218 kDa with subunits of 120 kDa and 93 kDa and was stable at 50 °C for 1 h. Optima of temperature and pH were 60 °C and 5.0-6.5, respectively. The enzyme was not affected significantly by most ions, detergents and organic solvents. While glucose did not affect the tannase activity, the addition of a high concentration of gallic acid did. The Km values were 1.7 mM (tannic acid), 14.3 mM (methyl-gallate) and 0.6 mM (propyl-gallate). The enzyme was able to catalyze the transesterification reaction to produce propyl-gallate. All biochemical properties suggest the biotechnological potential of the glucose- and solvent-tolerant tannase from A. phoenicis. © 2012 Elsevier B.V. All rights reserved.

Inoculation of salivary gland extracts obtained from female of Rhipicephalus sanguineus (Latreille, 1806) (Acari, Ixodidae) with 2, 4, and 6 days of feeding in rabbit: I - Histopathology of the feeding lesion

This study analyzed the histopathology of rabbit skin, previously immunized with SGE2, SGE4, and SGE6 gland extracts prepared from salivary glands of Rhipicephalus sanguineus female with 2, 4, and 6 days of feeding, at the region of the R. sanguineus female feeding lesion 2, 4, and 6 days after tick attachment. In this work, infestation-naïve New Zealand White rabbits were inoculated either with the extracts (test group (TG)) or with phosphate buffer and complete Freund's adjuvant mixture (control group 2 (CG2)). Each extract-inoculated- (TG and CG2) and non-inoculated (CG1) rabbit was subsequently infested with R. sanguineus. Skin biopsies were collected from the rabbit at the tick feeding lesion at 2, 4, and 6 days of feeding. Results revealed that rabbit immunization with gland extracts induced acquisition of resistance against this species. It should be stated that the SGE4 extract was the most effective in developing an immune-inflammatory response against ectoparasites, being this process characterized by the presence of an early and intense inflammatory cell infiltrate. On the other hand, SGE6 extract caused a later appearance of resistance with less infiltrate occurrence and intense edema at the feeding lesion site. As to the inflammatory process deriving from SGE2 extract inoculation, it was the less intense. It was concluded that immunization with different extracts from R. sanguineus female salivary glands did not change microscope features of the inflammatory process, although an earlier or more intense and later response, which was also dependent on the inoculate extract, was noticed. © 2012 Springer-Verlag Berlin Heidelberg.

Glucose homoeostasis in rats exposed to acute intermittent hypoxia

Aim: Chronic exposure to intermittent hypoxia commonly induces the activation of sympathetic tonus and the disruption of glucose homoeostasis. However, the effects of exposure to acute intermittent hypoxia (AIH) on glucose homoeostasis are not yet fully elucidated. Herein, we evaluated parameters related to glucose metabolism in rats exposed to AIH. Methods: Male adult rats were submitted to 10 episodes of hypoxia (6% O2, for 45 s) interspersed with 5-min intervals of normoxia (21%), while the control (CTL) group was kept in normoxia. Results: Acute intermittent hypoxia rats presented higher fasting glycaemia, normal insulinaemia, increased lactataemia and similar serum lipid levels, compared to controls (n = 10, P < 0.05). Additionally, AIH rats exhibited increased glucose tolerance (GT) (n = 10, P < 0.05) and augmented insulin sensitivity (IS) (n = 10, P < 0.05). The p-Akt/Akt protein ratio was increased in the muscle, but not in the liver and adipose tissue of AIH rats (n = 6, P < 0.05). The elevated glycaemia in AIH rats was associated with a reduction in the hepatic glycogen content (n = 10, P < 0.05). Moreover, the AIH-induced increase in blood glucose concentration, as well as reduced hepatic glycogen content, was prevented by prior systemic administration of the β-adrenergic antagonist (P < 0.05). The effects of AIH on glycaemia and Akt phosphorylation were transient and not observed after 60 min. Conclusions: We suggest that AIH induces an increase in blood glucose concentration as a result of hepatic glycogenolysis recruitment through sympathetic activation. The augmentation of GT and IS might be attributed, at least in part, to increased β-adrenergic sympathetic stimulation and Akt protein activation in skeletal muscles, leading to a higher glucose availability and utilization. © 2013 Scandinavian Physiological Society.

Purificação e caracterização bioquímica de tanases produzidas pelo fungo filamentoso Aspergillus phoenicis

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Interleucina 6 e proteinograma sérico de ovinos submetidos à endotoxemia experimental

Pós-graduação em Ciência Animal - FMVA

Intoxicação experimental de cães com folhas verdes de Nerium oleander e uso da frutose 1,6 difosfato e da glicose como tratamentos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Voltammetric determination of phosphate in brazilian biodiesel using two different electrodes

The presence of contaminants, such as phosphate, in biodiesel, has several drawbacks for instance: current engines perform poorly, fuel tanks deteriorate, catalytic conversion is damaged, and particles emission is increased. Therefore, biodiesel quality control is extremely important for biodiesel acceptance and commercialization worldwide. In this context, a bare glassy carbon electrode (GCE) and another chemically modified electrode with iron hexacyanoferrate (Prussian Blue – PB) were developed for determination of phosphate in biodiesel. The LODs of 6.44 and 1.19 mg kg−1, and LOQs of 21.43 and 3.97 mg kg−1 were obtained for the bare GCE and the PB-modified GCE, respectively. The methodology was employed for analysis of Brazilian biodiesel samples, and it led to satisfactory results, demonstrating its potential application for biodiesel quality control. Additionally, recovery and interference tests were conducted, which revealed that the developed methods are suitable for analysis of phosphate in biodiesel samples.

Desenvolvimento de sistem biomimético para análise de 3,5,6-Tricloro-2-piridinol, o principal metabólito do clorpirifós

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Square-wave voltammetric determination of rutin in pharmaceutical formulations using a carbon composite electrode modified with copper (II) phosphate immobilized in polyester resin

Descreve-se um eletrodo de carbono modificado com fosfato de cobre (II) imobilizado em uma resina de poliéster (Cu₃(PO₄)₂-Poly) para a determinação de rutina em amostras farmacêuticas por voltametria de onda quadrada. O eletrodo modificado permite a determinação de rutina em potencial (0.20 V vs Ag / AgCl (3,0 mol L^-1 KCl)) menor que o observado em um eletrodo não modificado. Verificou-se que a corrente de pico foi linear com a concentração de rutina na faixa de 9,9 × 10^-8 a 2,5 × 10^-6 mol L^-1, com um limite de detecção de 1,2 × 10^-8 mol L^-1. A resposta do eletrodo foi estável, sem variação significativa dentro de várias horas de operação contínua. A morfologia da superfície do eletrodo modificado foi caracterizada por microscopia eletrônica de varredura (MEV) e pelo sistema de energia dispersiva de raios-X (EDX). Os resultados obtidos foram precisos e exatos. Ademais, estes resultados estão de acordo com aqueles obtidos pelo método cromatográfico a um nível de confiança de 95%.

Otimização do cultivo de Lasiodiplodia theobromae para obtenção de EPS e caracterização física e química dos polissacarídeos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Amperometric glucose biosensor based on layer-by-layer films of microperoxidase-11 and liposome-encapsulated glucose oxidase

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

Stimuli-Responsive Biointerface Based on Polymer Brushes for Glucose Detection

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

EPR, optical absorption and luminescence studies of Cr3+-doped antimony phosphate glasses

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)