Biochemical and X-ray micro-computed tomographic analyses of critical size bone defects grafted with autogenous bone and mercerized bacterial cellulose membranes salified with alendronate.

OBJECTIVES: This study aimed to evaluate the repair of critical-sized bone defects grafted with autogenous bone and mercerized bacterial cellulose membranes (BCm) salified with alendronate (ALN). METHODS: Forty-eight male Wistar rats underwent surgery to create a 5 mm-diameter bone defect in the calvarium. The removed bone was particularized, regrafted into the defect, and covered by a BCm according to the group: control group (CG), simply mercerized BCm; group 1 (G1), negatively charged BCm (BCm-CM-) salified with ALN; and group 2 (G2), positively charged BCm (BCm-DEAE+) salified with ALN. Serum samples were collected preoperatively and before euthanasia to analyze osteoprotegerin (OPG), parathyroid hormone (PTH), sclerostin (SOST), and fibroblast growth factor 23 (FGF23) levels. The animals were euthanized after 15 or 60 d. Calvaria were analyzed using quantitative microtomography (µCT). RESULTS: There was an increased level of PTH in the CG compared to the G2 group, at day 60 (p = 0.019). When analyzing the same group over time, G1 presented an increased FGF23 level on days 15 and 60 (p < 0.05). CG presented an increase in PTH (p = 0.037) at day 60. The µCT analysis detected increased trabecular separation on day 15 in G2 compared to G1 (p = 0.040). CONCLUSIONS: Salification of ionized BCm with ALN had no direct effect on bone repair; however, BCm-CM- increased the levels of FGF23 over time. BCm-DEAE+ decreased PTH levels compared to mercerized BCm. BCm-CM-salified with ALN-induced superior bone quality, with respect to trabecular separation, compared to BCm-DEAE+.

Accelerating the Morphogenetic Cycle of the Viral Vector Aedes aegypti Larvae for Faster Larvicidal Bioassays.

Any bioassay to test new chemically synthesized larvicides or phytolarvicides against Culicidae and more harmful mosquito species, such as Aedes aegypti and Aedes albopictus, which specifically transmit dengue, yellow fever, chikungunya viral fevers as well as Zika virus, or Anopheles gambiae, a vector for malaria and philariasis, requires thousands of well-developed larvae, preferably at the fourth instar stage. The natural morphogenetic cycle of Aedes spp., in the field or in the laboratory, may extend to 19 days at room temperature (e.g., 25°C) from the first permanent contact between viable eggs and water and the last stage of larval growth or metamorphosis into flying adults. Thus, accelerated sequential molting is desirable for swifter bioassays of larvicides. We achieved this goal in Aedes aegypti with very limited strategic and low-cost additions to food, such as coconut water, milk or its casein, yeast extract, and to a lesser extent, glycerol. The naturally rich coconut water was excellent for quickly attaining the population of instar IV larvae, the most advanced one before pupation, saving about a week, for subsequent larvicidal bioassays. Diluted milk, as another food source, allowed an even faster final ecdysis and adults are useful for mosquito taxonomical purpose.

Carotenoid Production by Halophilic Archaea Under Different Culture Conditions.

Carotenoids are pigments that may be used as colorants and antioxidants in food, pharmaceutical, and cosmetic industries. Since they also benefit human health, great efforts have been undertaken to search for natural sources of carotenoids, including microbial ones. The optimization of culture conditions to increase carotenoid yield is one of the strategies used to minimize the high cost of carotenoid production by microorganisms. Halophilic archaea are capable of producing carotenoids according to culture conditions. Their main carotenoid is bacterioruberin with 50 carbon atoms. In fact, the carotenoid has important biological functions since it acts as cell membrane reinforcement and it protects the microorganism against DNA damaging agents. Moreover, carotenoid extracts from halophilic archaea have shown high antioxidant capacity. Therefore, current review summarizes the effect of different culture conditions such as salt and carbon source concentrations in the medium, light incidence, and oxygen tension on carotenoid production by halophilic archaea and the strategies such as optimization methodology and two-stage cultivation already used to increase the carotenoid yield of these microorganisms.

Thermopressurized diluted phosphoric acid pretreatment of ligno(hemi)cellulose to make free sugars and nutraceutical oligosaccharides.

Ligno(hemi)cellulosics (L(h)Cs) as sugarcane bagasse and loblolly pine sawdust are currently being used to produce biofuels such as bioethanol and biobutanol through fermentation of free sugars that are often obtained enzymatically. However, this bioconversion requires a pretreatment to solubilize the hemicellulose fractions, thus facilitating the action of the cellulolytic enzymes. Instead of the main free monosaccharides used in these current models, the modulation of thermopressurized orthophosphoric acid as a pretreatment, in the ranges of 3-12 atm and pH 1.5-2.5, can produce nondigestible oligosaccharides (NDOS) such as xylo-oligosaccharides (XOS) because heteroxylan is present in both types of hardwood and softwood hemicelluloses. A comparative thin-layer chromatographic analysis of the hydrolytic products showed the best conditions for NDOS production to be 7 atm/water, pH 2.25 and 2.50, and 8.5 atm/water for both sources. Particular hydrolysates from 7 atm (171 °C) at pHs 2.25 and 2.50 both for cane bagasse and pine sawdust, with respective oligosaccharide contents of 57 and 59 %, once mixed in a proportion of 1:1 for each plant source, were used in vitro as carbon sources for Bifidobacterium or Lactobacillus. Once both bacteria attained the stationary phase of growth, an unforeseen feature emerged: the preference of B. animalis for bagasse hydrolysates and, conversely, the preference of L. casei for pine hydrolysates. Considering the fact that nutraceutical oligosaccharides from both hemicelluloses correspond to higher value-added byproducts, the technology using a much diluted thermopressurized orthophosphoric acid pretreatment becomes an attractive choice for L(h)Cs.

Tyrosinase immobilized enzyme reactor: development and evaluation.

Immobilized enzyme reactors of tyrosinase (tyr-IMERs) for use on-line in HPLC system were prepared by different procedures and then compared. The enzyme, obtained from Agaricus bisporus, was immobilized on epoxy-silica which was prepared using different conditions. Enzyme immobilization was conducted by both in situ and in batch techniques. The different procedures were compared in terms of protein and activity retention, IMERs activity, kinetics and stability. The influence of immobilization procedure on enzyme activity and the behavior of the IMERs against a standard inhibitor were also investigated. In situ immobilization on epoxy-silica, synthesized using microwave assistance, provided the best conditions to prepare tyrosinase IMERs. The tyr-IMERs were successfully tested with known and potential inhibitors of tyrosinase, and the results showed that they can be used for the screening of inhibitors of that enzyme.

Fructo-oligosaccharide production from inulin through partial citric or phosphoric acid hydrolyses.

Purified inulin from Dahlia tubers was partially hydrolyzed to form fructo-oligosaccharides by using citric or phosphoric acids (pH, 2.0-2.5) as mild acid catalysts. The ideal kinetic conditions to ensure a high yield of fructo-oligosaccharides relative to free fructose were a temperature range of 85°C-95°C, a hydrolysis time of 15-25 minutes, and a catalyst pH of 2.5. At the higher temperature and the longest hydrolysis time, an inversion of the product ratio occurred. Under these conditions, co-generation of hydroxymethylfurfural occurred, and it was eliminated by activated charcoal. Unlike in classic hydrolysis with hydrochloric or sulfuric acid, deionization of the actual hydrolysates was not necessary because the catalyst neutralization with common bases results in the formation of co-nutrients with alternative uses as foods or fermentation substrates. These whole hydrolysates can be advantageously added as nutraceuticals to carbonated beverages and acidic foods, such as soft drinks and yogurts.

Biodiesel from uncommon fatty acids.

Ethyl esters from uncommon fatty acids, such as valproic, azelaic, and sorbic acids, were chemically synthesized and identified by gas chromatography or liquid chromatography coupled to mass spectrometry. Some properties were evaluated to determine their potential for use as biofuels or in other commercial applications. They have remarkable and pleasant odors and, in the case of ethyl ester in valproic acid, display marked resistance to clouding and crystallization.

Sound is involved in multimodal communication of Loxosceles intermedia Mello-Leitão, 1934 (Araneae; Sicariidae).

Signals of different modalities are involved during courtship of the brown spider Loxosceles intermedia. A spine on the pedipalp is rubbed against the grooves on the retrolateral region of the chelicerae producing stridulatory signals, which have a dominant frequency of the airborne component range around 770 Hz for females and around 170 Hz for males. These values are significantly lower for the substrate-borne component. The sound pressure level of stridulatory signals lies below 50 dB and the velocity values below 1mm/s. The copulation frequency does not depend on the presence of pedipalps in females; however, in males the removal of pedipalps decreases the courtship frequency. During courtship, females vibrate their abdomens after being touched by the courting male, producing tremulatory signals with the dominant frequency below 100 Hz, sound pressure level below 60 dB and velocity below 3mm/s. This vibration may function as a sign of the akinesia state since it precedes the introduction of the embolus. Cuticular compounds probably determine the recognition of the male by the female. Data from the present study corroborate the generalist nature of L. intermedia in which signals of different modalities are used during courtship.

Exotic flora dependence of an unusual Brazilian propolis: the pinocembrin biomarker by capillary techniques.

Significant amounts of pinocembrin (>10%), a dihydroxy-flavanone, was found in the composition of an unusual brand of a subtropical Brazilian propolis. Incidentally, this sealing material was obtained from hives surrounding a large forestry site based on a single exotic flora, namely poplar (Populus sp.). Examination of the different botanical parts of poplar revealed the buds as the main source of the flavanone. Techniques used for the establishment of the chemical correlation between the propolis brand and the poplar buds were TLC/densitometry, capillary GC-MS in the e.i. mode, and CZE with DAD monitoring. Since color enhancement after Al3+ complexation applies just for more hydroxylated flavonoids, the alternative techniques herein applied were of value for pinocembrin detection and estimation. Analytical data indicated the dominance of the main phenolic pinocembrin biomarker as well as the presence of other related flavonoids in the botanical source and in the propolis derived thereof.

Cytotoxic limonoids from Brazilian Melia azedarach.

Three new C-seco limonoids (1-3) and one new tetracyclic limonoid (4) were isolated from a methanol extract of the ripe fruits of Melia azedarach collected in Curitiba, Brazil, and their structures were elucidated by spectroscopic data analysis and comparison of spectral data with those of the previously known compounds. Among the limonoids isolated in the present study, compounds 3 and 4 exhibited significant inhibitory activity against HeLa S3 cancer cells, whereas 1 and 2 showed weak cytotoxicity.

Effect of feeding methods on the astaxanthin production by Phaffia rhodozyma in fed-batch process

O efeito da alimentação na produção de astaxantina pela levedura Phaffia rhodozyma ATCC 24202 foi estudado, utilizando processos descontínuo alimentado com alimentação contínua e intermitente, e matérias-primas de baixo custo como substratos (caldo de cana de açúcar e uréia). Em processos descontínuo alimentado com alimentação contínua, uma concentração celular de astaxantina de 383,73 µg/g biomassa foi obtida. Entretanto, em processos descontínuo alimentado com alimentação intermitente, uma redução na concentração celular de astaxantina (303,34 µg/g biomassa) foi observada. Desta forma, processos descontínuo alimentado com alimentação contínua poderiam ser uma alternativa na produção industrial de astaxantina, permitindo um aumento na produtividade de biomassa sem perdas na produção de astaxantina pela levedura.

New ring C-seco limonoids from Brazilian Melia azedarach and their cytotoxic activity.

A methanol extract of the ripe fruits of Melia azedarach collected in Curitiba, Parana, Brazil, afforded seven new ring C-seco limonoids (1-7) together with three known limonoids (8-10). The structures of the new compounds were elucidated by NMR and MS analysis and comparison of spectral data with those of previously known compounds. Compounds 4 and 5 exhibited significant inhibitory activity against HeLa S3 cancer cells, whereas 1, 2, 3, and 8 showed weak cytotoxicity.

Optimization of biomass and astaxanthin production by the yeast Phaffia rhodozyma

The combination of fed-batch processes and low cost substrates (sugar cane juice and urea) was studied in view of the optimization of biomass and astaxanthin production by the yeast Phaffia rhodozyma ATCC 24202. In the optimized process, a biomass and astaxanthin productivity of 0.327 g/l/h and 0.124 mg/l/h was achieved, respectively. Compared to the batch process studied, an increase of approximately 4.55-fold in the biomass productivity and 4.73-fold in the astaxanthin productivity was found

Cultivo da levedura Phaffia rhodozyma (Xanthophyllomyces dendrorhous) em processo descontínuo alimentado para produção de astaxantina / Cultivation of Phaffia rhodozyma (Xanthophyllomyces dendrorhous) yeast in discontinuous system to obtain astaxanthin

A levedura Phaffia rhodozyma, produtora de astaxantina, pigmento carotenóide largamente empregado na aqüicultura de peixes e crustáceos, pode ser eficientemente cultivada num meio de cultura de baixo custo, à base de caldo de cana diluído 1:10 e uréia a 1 g/L. No entanto, a produção de biomassa e a formação do carotenóide sofrem a inibição pelo substrato (efeito "Crabtree"), limitando desta forma a utilização do caldo de cana com concentrações da fonte de carbono superiores a 20 g/L, importante consideração na produção industrial de astaxantina. No presente trabalho, o cultivo da levedura P. rhodozyma foi realizado em processo descontínuo alimentado...