Evaluation of Sample Preparation Procedures for Determination of Cr(VI) in Cr2O3 Pigments by Vis Spectrophotometry

Abstract Six sample preparation procedures were evaluated for selective extraction of Cr(VI) from commercial samples of chromium oxide green (Cr2O3) pigments prior to formation of its diphenylcarbazone complex [CrDPCO]- for determination by visible spectrophotometry: (I) water-soluble chromium; (II) EPA method 3060A without Mg2+; (III) EPA method 3060A with Mg2+; (IV) Na3PO4 based extraction; (V) method IRSA16 based on acidic extraction and; (VI) Na2CO3 based extraction. Evaluation of the influence of concomitant Cr(III) ions, time and stability of the [CrDPCO]- complex was investigated. Recoveries of soluble and insoluble Cr(VI) species were 86% and 80%, respectively, using procedure (VI). Direct calibration against aqueous standards prepared in the extraction medium was successful for Cr(VI) in the concentration range 0.05-1.50 μg L-1. Limits of detection and quantitation were 0.3 µg g-1 and 1.0 µg g-1, respectively, for 250 mg subsamples/25 mL. Procedure (VI) was applied to the analysis of four commercial samples of Cr2O3 pigments, three determined to have Cr(VI) within compliance limits below 1.0 µg g-1, but one at 16.6 ± 0.6 µg g-1, prohibiting use of this pigment in cosmetic formulations. This sample was conveniently employed to evaluate the accuracy of the method. The recommended procedure is simple and accurate and has been adopted by Tecpar's laboratory of Parana Institute of Technology (Curitiba, Brazil).

Improvement of anther cultures conditions using the Taguchi method in three cereal crops

Background: Plant tissue cultures have the potential to reprogram the development of microspores from normal gametophytic to sporophytic pathway resulting in the formation of androgenic embryos. The efficiency of this process depends on the genotype, media composition and external conditions. However, this process frequently results in the regeneration of albino instead of green plants. Successful regeneration of green plants is affected by the concentration of copper sulfate (CuSO4) and silver nitrate (AgNO3) and the length of induction step. In this study, we aimed at concurrent optimization of these three factors in barley (Hordeum vulgare L.), wheat (Triticum aestivum L.), and triticale (x Triticosecale spp. Wittmack ex A. Camus 1927) using the Taguchi method. We evaluated uniform donor plants under varying experimental conditions of in vitro anther culture using the Taguchi approach, and verified the optimized conditions. Results: Optimization of the regeneration conditions resulted in an increase in the number of green regenerants compared with the control. Statistic Taguchi method for optimization of the in vitro tissue culture plant regeneration via anther cultures allowed reduction of the number of experimental designs from 27 needed if full factorial analysis is used to 9. With the increase in the number of green regenerants, the number of spontaneous doubled haploids decreased. Moreover, in barley and triticale, the number of albino regenerants was reduced. Conclusion: The statistic Taguchi approach could be successfully used for various factors (here components of induction media, time of incubation on induction media) at a one time, that may impact on cereals anther cultures to improve the regeneration efficiency

Spray Drying of Coloring Extracts Produced by Fungi Isolated from Brazilian Caves

Abstract Pigments produced by submerged fermentation of three filamentous fungi isolated from Brazilian caves, namely Aspergillus keveii, Penicillium flavigenum, and Epicoccum nigrum, were submitted to spray drying in presence of the adjuvants maltodextrin, modified starch or gum arabic. Yellow fine powders with low moisture content and water activity, and high color retention (> 70%) were successfully generated with a high product recovery ratio (> 50%), independently of the adjuvant used. The dried products have enhanced stability and potential to might be used as a natural colorant in food and pharmaceutical applications.

Responses of antioxidant enzymes, photosynthetic pigments and carbohydrates in micropropagated Pitcairnia encholirioides L.B. Sm. (Bromeliaceae) under ex vitro water deficit and after rehydration / Respostas de enzimas antioxidantes, pigmentos fotossintéticos e carboidratos em Pitcairnia encholirioides L.B. Sm. (Bromeliaceae) micropropagadas, sob déficit hídrico ex vitro e após reidratação

Abstract In this study, the activities of antioxidant enzymes, photosynthetic pigments, proline and carbohydrate contents in Pitcairnia encholirioides under ex vitro conditions of water deficit were evaluated. Results show that plants under progressive water stress, previously in vitro cultured in media supplemented with 30 g L-1 sucrose and GA3, accumulated more proline and increased peroxidase (POD) activity and the contents of photosynthetic pigments and carbohydrates. For plants previously in vitro cultured with 15 g L-1 sucrose and NAA, no differences were found for proline content and there were reductions in activities of peroxidase (POD), catalase (CAT) and poliphenoloxidase (PPO), and in contents of carbohydrates, with progress of ex vitro water deficit. After rehydration, plants showed physiological recovery, with enzymatic activities and contents of metabolites similar to those found in the controls not submitted to dehydration, regardless of the previous in vitro culture conditions. These results show that micropropagated P. encholirioides has high tolerance to dehydration once in ex vitro conditions, which can ensure the survival of plants from tissue culture when transferred to its natural environment, emphasizing the importance of such biotechnology for the propagation of endangered species.

Resumo Neste estudo, foram avaliadas as atividades de enzimas antioxidantes, pigmentos fotossintéticos, conteúdo de prolina e carboidratos em Pitcairnia encholirioides sob déficit hídrico em condições ex vitro. Os resultados mostraram que as plantas sob estresse hídrico progressivo, previamente cultivadas in vitro em meio de cultura suplementado com 30 g L-1 de sacarose e GA3 acumularam mais prolina e aumentaram a atividade da peroxidase (POD) e os teores de pigmentos fotossintéticos e carboidratos. Para plantas previamente cultivadas in vitro com 15 g L-1 de sacarose e ANA, não foram encontradas diferenças nos conteúdos de prolina e houve reduções nas atividades da peroxidase (POD), catalase (CAT) e polifenoloxidase (PPO), e no conteúdo de carboidratos, com o progresso do déficit hídrico ex vitro. Após a reidratação, as plantas apresentaram recuperação fisiológica, com atividades enzimáticas e conteúdo de metabólitos semelhantes aos encontrados nos controles não sujeitos à desidratação, independentemente das condições de cultivo in vitro. Estes resultados mostram que P. encholirioides micropropagada tem alta tolerância à desidratação uma vez em condições ex vitro, o que pode garantir a sobrevivência de plantas provenientes da cultura de tecidos quando transferidas para seu ambiente natural, enfatizando a importância desta biotecnologia para a propagação de espécies ameaçadas.

L-DOPA extradiol dioxigenase de amanita muscaria: revisão da sequência codificadora, expressão heteróloga, caracterização funcional e contextualização filogenética / Amanita muscaria L-DOPA extradiol dioxygenase: coding sequence review, heterologous expression, functional characterization, and phylogenetic context

Extradiol dioxigenases são enzimas que catalisam a clivagem oxidativa de ligações C-C entre grupos hidroxila fenólicos adjacentes utilizando catecóis como substratos. Esta classe de enzimas é bem caracterizada em bactérias, onde catalisam a degradação de compostos aromáticos. Na maioria das plantas Caryophyllales, como a beterraba, primavera e a maravilha, L-3,4-diidroxifenilalanina (L-DOPA) extradiol dioxigenases (DODAs) catalisam a clivagem oxidativa de L-DOPA na posição 4,5 gerando o ácido betalâmico, aldeído precursor das betalaínas, uma classe de pigmentos naturais que substitui as antocianinas na pigmentação dessas espécies. Alguns fungos basidiomicetos também produzem betalaínas, como o agário-das-moscas (Amanita muscaria). Nesse organismo, DODA é capaz de catalisar uma clivagem adicional na posição 2,3 da L-DOPA, formando muscaflavina, um isômero do ácido betalâmico que dá origem a uma outra classe de pigmentos naturais: as higroaurinas. Desde a caracterização do gene dodA, o qual codifica para a DODA de A. muscaria (AMAMU), não existem relatos na literatura que explorem a promiscuidade catalítica desta enzima, sua relação com outras linhagens de DODAs e a síntese quimioenzimática de betalaínas a partir desta enzima. Dessa forma, buscamos contextualizar as relações filogenéticas e funcionais entre AMAMU e diferentes linhagens de DODAs, bem como estabelecer um método que viabilize a clonagem, expressão heteróloga e caracterização funcional destaenzima. As análises filogenéticas revelaram que AMAMU possui uma evolução convergente com DODAs de plantas e bactérias e que, apesar de AMAMU ser funcionalmente homóloga à DODA da bactéria Escherichia coli, esta última apresenta homologia com DODAs de plantas. Logo, não há uma relação direta entre a sequência primária de DODAs e sua função. Nós também demonstramos que não há uma relação entre a expressão de transcritos de BvDODA1, e de seu parálogo BvDODA2, e a diferença de pigmentação entre variedades de beterrabas amarelas e vermelhas. A clonagem da sequência codificadora (CDS) publicada para o gene dodA de A. muscaria resultou na retenção do primeiro íntron, o que impedia a sua expressão. Então, uma nova CDS de 558 nucleotídeos foi proposta para este gene, a qual inclui um códon de início da tradução que se mantém na fase de leitura e codifica para uma proteína de 185 resíduos, 43 a menos que AMAMU. A expressão desta CDS resultou na proteína recombinante AmDODA, capaz de catalisar a síntese de ácido betalâmico e muscaflavina a partir de L-DOPA e D-DOPA. AmDODA possui um tamanho aproximado de 22 kDa, com um pH ótimo de atividade de 8,5 e uma constante de Michaelis (KM) de 3,7 ± 0,9 mmol L-1 e de velocidade máxima (Vmax) de 3,3 ± 0,4 µ mol min-1 mg-1. Sua utilização foi demonstrada na síntese quimioenzimática de betalaínas-modelo com potencial aplicação como sondas para microscopia confocal de fluorescência de dois fótons. Neste contexto, esta Tese explora os aspectos moleculares, bioquímicos e biológicos da DODA do fungo A. muscaria e traz importantes contribuições acerca da pigmentação por betalaínas na natureza

Extradiol dioxigenases are enzymes that catalyze the oxidative cleavage of C-C bonds between adjacent phenolic hydroxyl groups using catechols as substrates. This class of enzymes is well characterized in bacteria, where they catalyze the degradation of aromatic compounds. In most plants of the Order Caryophyllales, such as beet, paperflower and four o'clock flower, L-3,4-dihydroxyphenylalanine (L-DOPA) extradiol dioxygenases (DODAs) catalyze the oxidative 4,5-cleavage of L-DOPA generating the betalamic acid, an aldehyde precursor of the betalains, a class of natural pigments that replaces anthocyanins in the pigmentation of these species. Some basidiomycete fungi also produce betalains, such as the fly agaric (Amanita muscaria). In this organism, DODA is able to catalyze an additional 2,3-cleavage of L-DOPA, yielding muscaflavine, an isomer of betalamic acid that gives rise to another class of natural pigments: the hygroaurins. Since the characterization of the dodA gene, which encodes the A. muscaria DODA (AMAMU), there are no reports in the literature that explore the catalytic promiscuity of this enzyme, its relation to other DODAs and the chemoenzymatic synthesis of betalains from this enzyme. Thus, we seek to contextualize the phylogenetic and functional relationships between AMAMU and different DODA lineages, as well as to establish a method that enable the cloning, heterologous expression and functional characterization of this enzyme. Phylogenetic analysis revealed that AMAMU has a convergent evolutionwith plant and bacterial DODAs and that although AMAMU is functionally homologous to the DODA of the Escherichia coli bacteria, this latter is homologous to the plant DODAs. Therefore, there is no direct relationship between the primary sequence of DODAs and their function. We have also shown that there is no relationship between the expression of BvDODA1 transcripts, and its BvDODA2 paralogue, and the pigment difference between yellow and red beet varieties. Cloning of the published coding sequence (CDS) for the dodA gene of A. muscaria resulted in the retention of the first intron, which prevented its expression. Then, a new CDS of 558 nucleotides was proposed for this gene, which includes a translation start codon that remains in the open reading frame and encodes for a protein 185 residues long, 43 less than AMAMU. Expression of this CDS resulted in the recombinant AmDODA protein, able to catalyze the synthesis of betalamic acid and muscaflavine from L-DOPA and D-DOPA. AmDODA has an approximate size of 22 kDa, with an optimum activity pH of 8.5 and a Michaelis constant (KM) of 3.7 ± 0.9 mmol L-1 and a maximum velocity (Vmax) of 3.3 ± 0.4 µmol min-1 mg-1. Its use was demonstrated in the chemoenzymatic synthesis of betalains-model with potential application as probes for confocal microscopy of two-photon fluorescence. In this context, this thesis explores the molecular, biochemical and biological aspects of the DODA of the fungus A. muscaria and brings important contributions about the pigmentation by betalains in nature

Influence of High Light Intensity and Nitrate Deprivation on Growth and Biochemical Composition of the Marine Microalgae Isochrysis galbana

Abstract Isochrysis galbana is a brown microalgae widely used as a feed for marine organism in aquaculture. The aim of present study is to investigate the growth, biochemical composition, fatty acid profile, photosynthetic parameters and antioxidant activity (radical scavenging activity) of Isochrysis galbana cells cultivated under different levels (sub-optimum; 50 ± 1.5,optimum; 125 ± 2.5 and supra-optimum; 325 ± 3.5 µmol photons m-2 s -1) of photosynthetic active radiation (PAR), and subsequently treated with different concentration of nitrate deprivation (8mM, 2mM and 0.5mM). The experiment was carried out under controlled conditions utilizing a factorial design 3x3 (light intensity and nitrate concentration). The result depicts that PAR positively influences the growth of Isochrysis galbana which is maximum under supra-optimum PAR. Nitrate deprivation (2mM & 0.5mM) induced decline in growth in terms of dry weight is observed as 60.1% & 61.9% in suboptimum and 26.5% and 34.9% in supra-optimum respectively over the values recorded in their respective controls. Supra-optimum PAR decreased primary photosynthetic pigment Chl a and Chl c by 15.7% and 8.5%, whereas carotenoid content increased by 45.9% in supra-optimum PAR which displays potential interest as antioxidant agent in addition to total phenolic content and radical scavenging activity. The results suggest that combined stress of high light and nitrogen deprivation shifts the metabolic physiology from protein synthesis to energy reserve (carbohydrate and lipid) and accumulation of saturated fatty acid on expense of unsaturated fatty acid except docosahexaenoic acid. These valuable compounds exhibit potential applications in mariculture, nutraceutical and biofuel industry.

Efecto del Extracto de Maíz Morado "Chicha Morada" durante el blanqueamiento Dental. In vitro / Effect of Purple Corn Beverage "Chicha Morada" During Dental Bleaching. In vitro

RESUMEN: El resultado del tratamiento de blanqueamiento dental puede verse afectado en pacientes que consumen bebidas pigmentantes durante el tratamiento. El objetivo de este trabajo consistió en valuar el efecto in vitro de la exposición al extracto de maíz morado (chicha morada) sobre el color del esmalte humano, durante y después del tratamiento del blanqueamiento dental con peróxido de hidrógeno al 35 %. Se utilizaron 48 dientes humanos, divididos en grupos según la bebida a la que se expuso: Extracto de maíz morado peruano (MM), té verde (T) y agua destilada (A); la mitad de los especímenes expuestos a cada bebida fueron sometidos a blanqueamiento dental con peróxido de hidrógeno al 35 % durante los primeros días de exposición a la pigmentación, resultando en los siguientes grupos: Grupo A: Sin blanqueamiento + maíz morado, Grupo B: Sin blanqueamiento + té verde, Grupo C: Sin blanqueamiento + agua destilada, Grupo D: Con blanqueamiento + maíz morado, Grupo E: Con blanqueamiento + té verde, Grupo F: Con blanqueamiento + agua destilada. Los cambios de color se midieron con un espectrofotómetro digital (VITA Easyshade Advance 4.0, VITA, Alemania) antes del blanqueamiento, durante el blanqueamiento, finalizado el blanqueamiento y al final de los 36 días de exposición a los pigmentos. Según el ∆E, el extracto de maíz morado difiere significativamente con el agua destilada (p < 0,05). Con respecto al grado de luminosidad, el extracto de maíz morado con blanqueamiento presentó los menores valores de luminosidad (p < 0,05). En cuanto al croma, no hubo diferencias entre los grupos (p > 0,05). La exposición al extracto de maíz morado pigmenta los dientes, durante el blanqueamiento el extracto de maíz morado no afecta el tratamiento, pero si la exposición continúa luego del blanqueamiento dental, el color de los dientes se verá afectado.

ABSTRACT: The result of tooth whitening treatment may be affected in patients who consume staining drinks during treatment. The aim of this work was to evaluate the in vitro effect of the exposure to purple corn extract (chicha morada) on human enamel color, during and after the treatment of teeth whitening with 35 % hydrogen peroxide. Forty-eight human teeth were used, divided into groups according to the drink to which it was exposed: Peruvian purple corn extract (MM), green tea (T) and distilled water (A); half of the specimens exposed to each drink were subjected to tooth whitening with 35 % hydrogen peroxide during the first days of exposure to pigmentation, resulting in the following groups: Group A: Without bleaching + purple corn, Group B: Without whitening + green tea, Group C: No whitening + distilled water, Group D: With whitening + purple corn, Group E: With whitening + green tea, Group F: With whitening + distilled water. The color changes were measured with a digital spectrophotometer (VITA Easyshade Advance 4.0, VITA, Germany) before bleaching, during whitening, after whitening and at the end of 36 days of exposure to pigments. According to the ∆E, the purple corn extract differs significantly with the distilled water (p <0.05). Regarding the degree of luminosity, the purple corn extract with whitening presented the lowest luminosity values (p <0.05). As for the chroma, there were no differences between the groups (p> 0.05). Exposure to purple corn extract pigments the teeth, during whitening the purple corn extract does not affect the treatment, but if the exposure continues after tooth whitening, the color of the teeth will be affected.

O uso do gel de glicerina melhora a estabilidade de cor de resinas compostas? / Does the use of glycerin gel improve the color stability of composite resins?

Introdução: A camada superficial de resina composta não polimerizada, em função da presença do oxigênio, ocasiona problemas clínicos, como alteração de cor por absorção de pigmentos. Objetivo: Determinar o efeito de diferentes técnicas usadas no controle da formação da camada de dispersão sobre as propriedades ópticas de uma resina composta comercial. Material e método: Espécimes foram produzidos com a resina composta Estelite Sigma. A fotoativação foi conduzida com uma fonte de luz LED Bluephase G2 (1.200 mW/cm2 por 40 s). Os grupos foram determinados em função de três técnicas distintas: 1) sem tratamento (controle); 2) fotoativação com gel de glicerina; 3) polimento com lixa abrasiva após a fotoativação. A estabilidade de cor (ΔE) e o parâmetro de translucidez foram determinados pelo método de espectroscopia de reflectância (Easyshade Compac, Vita) empregando o parâmetro CIELab. As análises foram realizadas imediatamente após a fotoativação e repetidas após 7 dias de armazenamento em água ou em café. Os resultados foram submetidos à análise de variância e ao teste de Tukey (α = 0,05). Resultado: Não houve diferença para ΔE nos grupos envelhecidos em água. Quando armazenados em café, o grupo controle apresentou o maior valor de ΔE, enquanto o grupo polido gerou a menor alteração de cor. A aplicação do gel de glicerina produziu resultados intermediários. O parâmetro de translucidez não foi afetado pelos tratamentos testados. Conclusão: O uso do gel de glicerina minimiza a alteração de cor nas regiões de difícil acesso aos instrumentos de acabamento e de polimento.

Introduction: The resin composite superficial layer not polymerized due to the presence of oxygen leads to clinical problems as color alteration by the absorption of pigments. Objective: Evaluate the effect of different techniques to control the formation of the composite resin dispersion layer on the optical properties of a commercial composite. Material and method Resin composite Estelite Sigma specimens were made. The specimens were light-cured with the LED Bluephase G2 device (1200 mW/cm2 - 40 s). The groups were determined according to three different techniques: 1) no treatment (control); 2) light-curing through a glycerin gel layer on the surface; 3) polishing with abrasive discs after light-curing. The color stability (ΔE) and the translucency parameter were determined by the spectroscopy method (Easyshade Compact Vita) as a function of the CIELab parameter. The analyzes were performed immediately after photoactivation and repeated after 7 days of storage in water or 7 days in coffee. The results were submitted to ANOVA and Tukey test (α = 0.05). Result : No difference was found for ΔE in groups aged in water. When stored in coffee, the control group had the highest value of ΔE while the polished group generated the lowest color change. The glycerin gel groups promoted intermediated results. The translucency parameter was not affected by the treatments tested. Conclusion: The glycerin-based gel layer minimizes the color change in those regions that the finishing and polishing instruments are difficult to access.

Photoprotection enhanced by red cell wall pigments in three East Antarctic mosses

BACKGROUND: Antarctic bryophytes (mosses and liverworts) are resilient to physiologically extreme environmental conditions including elevated levels of ultraviolet (UV) radiation due to depletion of stratospheric ozone. Many Antarctic bryophytes synthesise UV-B-absorbing compounds (UVAC) that are localised in their cells and cell walls, a location that is rarely investigated for UVAC in plants. This study compares the concentrations and localisation of intracellular and cell wall UVAC in Antarctic Ceratodon purpureus, Bryum pseudotriquetrum and Schistidium antarctici from the Windmill Islands, East Antarctica. RESULTS: Multiple stresses, including desiccation and naturally high UV and visible light, seemed to enhance the incorporation of total UVAC including red pigments in the cell walls of all three Antarctic species analysed. The red growth form of C. purpureus had significantly higher levels of cell wall bound and lower intracellular UVAC concentrations than its nearby green form. Microscopic and spectroscopic analyses showed that the red colouration in this species was associated with the cell wall and that these red cell walls contained less pectin and phenolic esters than the green form. All three moss species showed a natural increase in cell wall UVAC content during the growing season and a decline in these compounds in new tissue grown under less stressful conditions in the laboratory. CONCLUSIONS: UVAC and red pigments are tightly bound to the cell wall and likely have a long-term protective role in Antarctic bryophytes. Although the identity of these red pigments remains unknown, our study demonstrates the importance of investigating cell wall UVAC in plants and contributes to our current understanding of UV-protective strategies employed by particular Antarctic bryophytes. Studies such as these provide clues to how these plants survive in such extreme habitats and are helpful in predicting future survival of the species studied.

Characterization and influence of subtropical persimmon cultivars on juice and jelly characteristics

ABSTRACT To increase the availability to consumers and add more value to persimmon (Diospyros kaki L.), which is a very perishable and seasonal fruit and in order to identify which cultivars grown in subtropical regions are more suitable for processing in the form of juice and jelly, as well as understand what the consumer profile is for these products, the objective of this study was to evaluate the influence of different persimmon cultivars (Rama Forte, Mel, Guiombo and Taubaté) grown in subtropical regions of Brazil on the physicochemical characteristics, rheological properties and sensory acceptance of the resulting juice and jelly in order to identify cultivars with the greatest potential for industrial use. The different studied persimmon cultivars had different physical and physicochemical characteristics which resulted in juices and jellies with different physicochemical, rheological and sensory characteristics. Based on sensory acceptance and productivity/adaptability of persimmon crop in Brazil, the most suitable persimmon cultivars for processing are Rama Forte and Guiombo. In this study it was found that the consumer prefers a more acidic persimmon juice and a less firm or softer, less sweet, clearer and more intense yellow color persimmon jelly.

Desempenho, sanidade animal e qualidade de filés de tilápias alimentadas com ração suplementada com biomassa bacteriana / Performance, animal health and fillets quality of tilapia fed diets supplemented with bacterial biomass

A aquicultura moderna é um dos setores de produção de alimentos que mais cresce no mundo. A tilápia, além de possuir grandes vantagens produtivas, origina produtos com grande aceitação pelo mercado. Em sua nutrição, podem ser utilizados aditivos com finalidades zootécnicas, pigmentantes ou antioxidantes. Este estudo objetivou avaliar o efeito da suplementação da dieta de tilápias com biomassa de Rubrivivax gelatinosus sobre o desempenho zootécnico e a saúde dos animais (histologia e hematologia) e sobre as características de qualidade dos filés (pH, composição químico-bromatológica, cor e rancidez). O experimento contou com seis tratamentos, compostos de um grupo controle, sem aditivos, um grupo contendo pigmentante comercial e quatro grupos com a biomassa nas concentrações de 175, 350, 700 e 1400mg/kg. Peixes pesando 21,42±5,65g foram criados por 74 dias em sistema com recirculação de água e, posteriormente, foram abatidos para a realização das análises. Não foram encontradas diferenças para os resultados das análises de desempenho, histológicas e hematológicas. Os filés dos grupos alimentados com os aditivos apresentaram menor umidade que o grupo controle, e os filés dos grupos alimentados com biomassa apresentaram as maiores teores proteicos. Não houve diferenças entre os tratamentos para os valores de pH, lipídeos e cinzas. Quanto à cor dos filés, todos os tratamentos com aditivos aumentaram a intensidade de vermelho. Em todos os tratamentos, a rancidez dos filés foi crescente durante o armazenamento, embora em menores valores nos filés dos grupos tratados com as maiores concentrações de biomassa. A biomassa de R. gelatinosus não promoveu alterações no desempenho nem na saúde animal e mostrou-se capaz de melhorar os aspectos de qualidade e conservação dos filés.

Modern aquaculture is one of the fastest growing food sectors in the world. Beyond having productivity advantages, tilapia fish yields products with great market acceptance. For its nutrition, additives aiming at increasing zootechnical, pigmenting or antioxidant features may be used. This study aimed to evaluate the effect of the supplementation of tilapia diets with Rubrivivax gelatinosus biomass on the performance and the health of animals (histology and hematology), and on the quality of fillets (pH, proximate composition, color and rancidity). The experiment comprised six treatments, made of a control group with no additives, a group containing commercial pigments and four groups with biomass at 175, 350, 700 and 1400 mg/kg. Fish weighing 21.42±5.65g were reared for 74 days in a system with water recirculation and slaughtered for analyzes. No differences were detected for performance, histological and hematological analyzes. Fillets of the groups fed additives had lower moisture content than the control group while the fillets of the groups fed the biomass had the highest protein percentages. No differences were detected among treatments for pH​, lipids and ash values. Regarding to the color of the fillets, all treatments with additives increased redness. For all treatments, rancidity in the fillets increased during storage, although the groups treated with the highest biomass concentrations had the lowest values. R. gelatinosus biomass did not change performance and animal health, and proved to be capable of improving fillets quality features and conservation.

Detection of seasonal asymptomatic dermatophytes in Van cats

Abstract The Van cat is a domestic landrace found in the Van province of eastern Turkey. In this study, we aimed to determine the seasonal carriage of dermatophytes in Van cats without clinical lesions. A total of 264 hair specimens were collected from clinically healthy cats in and around the Van Province. Of these samples, 30.3% were obtained in spring, 30.6% in summer, 16.6% in autumn, and 22.3% in winter; 45.1% of samples were from male cats and the rest from female ones. Of the studied cats, 118 were younger than 1 year, 78 were 1–3 years old, and 68 were older than 3 years. The specimens were subjected to direct microscopic examination with 15% potassium hydroxide and cultured on Sabouraud dextrose agar and dermatophyte test medium supplemented with cycloheximide and chloramphenicol. Dermatophyte identification was carried out based on macroscopic and microscopic colony morphology, urease activities, in vitro hair perforation test, growth at 37 °C, and pigmentation on corn meal agar. Dermatophytes were isolated from 19 (7.1%) of the 264 specimens examined. The most frequently isolated fungi were Trichophyton terrestre (4.1%), followed by Microsporum gypseum (1.1%), M. nanum (1.1%), and T. mentagrophytes (0.7%), and these fungi may represent a health risk for humans in contact with clinically healthy Van cats. M. canis was not isolated from any of the specimens. Our results show no significant (p > 0.05) association between carriage of dermatophytes and the gender of cats. The carriage rate of dermatophytes was high in spring and winter, and the only possible risk factor for infection was age of the animal.

Black stains and dental caries in Brazilian schoolchildren: a cross-sectional study

Abstract The aim of this study was to assess the prevalence of black stains (BS) and factors associated with their occurrence and to investigate the association of BS with caries experience after adjusting for other risk indicators. A school-based, cross-sectional study using multistage sampling of children aged 10-12 years from 20 private and public schools in Pelotas/Southern Brazil was conducted (n = 706). Children were evaluated for BS and dental caries (DMFT/dmft index) and socioeconomic information was collected by questionnaire. Univariate and multivariate Poisson regressions were used to assess variables associated with the prevalence of BS and with caries experience. The prevalence of BS was 5.81%. The mean DMFT/dmft was 1.54 (±1.91), with a maximum value of 10. Among the children with BS, mean dmft/DMFT was 1.22 (SD 1.68), with a maximum value of 6. After adjustments for demographics and socioeconomic variables, dental plaque and tooth brushing habits, prevalence of BS was associated with lower caries experience (RR 0.67; 95%CI 0.49-0.92). In conclusion, the presence of BS showed an association with lower dental caries experience in the evaluated population. Future studies should investigate the mechanisms behind this association.

A new species of Panaqolus (Siluriformes: Loricariidae) from the rio Madeira basin with remarkable intraspecific color variation

The rio Madeira is the largest white-water tributary of the Amazon, and is currently the river drainage with the highest fish species diversity in the world. A new species of Panaqolus was recognized from the middle Madeira and Mamoré rivers (Brazil) and from the Madre de Dios drainage (Peru) and it is described herein. This new species is readily distinguished from its congeners by the large number of white dots distributed all over the body and by its remarkable amplitude of color pattern variation, ranging from a pale, light brown, to dark brown and almost black background coloration. The new species closely resembles P. albomaculatus but has more and smaller dots on the body, a smaller orbital diameter (12.5-16.8% head length vs. 16.0-20.0%) and longer maxillary barbels (9.7-19.6% head length vs. 1.6-8.9%). The new species is the second of the genus Panaqolus described for a Brazilian location after nearly 80 years of the description of P. purusiensis.

O rio Madeira é o maior afluente de água branca do rio Amazonas e é atualmente o rio com o maior número de espécies do mundo. Uma nova espécie de Panaqolusfoi reconhecida do médio rio Madeira, do rio Mamoré (ambos no Brasil) e da bacia do Río Madre de Dios (Peru) e é descrita aqui. Esta nova espécie se distingue de suas congêneres pela grande quantidade de pontos brancos espalhados pelo corpo e grande variabilidade na sua coloração, variando de um fundo branco a marrom claro até marrom escuro e quase preto. A espécie se assemelha a P. albomaculatus da qual se distingue por ter mais manchas de menor tamanho no corpo, olhos menores (12,5-16,8% do comprimento da cabeça vs. 16,0-20,0%) e barbilhões maxilares mais compridos (9,7-19,6% comprimento da cabeça vs. 1,6-8,9%). A nova espécie é a segunda de Panaqolus descrita para uma localidade no Brasil, aproximadamente 80 anos após a descrição de P. purusiensis.

Enhanced production of prodigiosin by Serratia marcescens MO-1 using ram horn peptone

This work addresses the production of prodigiosin from ram horn peptone (RHP) using MO-1, a local isolate in submerged culture. First, a novel gram-negative and rod-shaped bacterial strain, MO-1, was isolated from the body of the grasshopper (Poecilemon tauricola Ramme 1951), which was collected from pesticide-contaminated fields. Sequence analysis of 16S rDNA classified the microbe as Serratia marcescens. The substrate utilization potential (BIOLOG) and fatty acid methyl ester profile (FAME) of S. marcescens were also determined. The effect of RHP on the production of prodigiosin by S. marcescens MO-1 was investigated, and the results showed that RHP supplementation promoted the growth of MO-1 and increased the production of prodigiosin. A concentration of 0.4% (w/v) RHP resulted in the greatest yield of prodigiosin (277.74 mg/L) after 48 h when mannitol was used as the sole source of carbon. The pigment yield was also influenced by the types of carbon sources and peptones. As a result, RHP was demonstrated to be a suitable substrate for prodigiosin production. These results revealed that prodigiosin could be produced efficiently by S. marcescens using RHP.

Epiphytic marine pigmented bacteria: A prospective source of natural antioxidants

Awareness on antioxidants and its significance in human healthcare has increased many folds in recent time. Increased demand requisite on welcoming newer and alternative resources for natural antioxidants. Seaweed associated pigmented bacteria screened for its antioxidant potentials reveals 55.5% of the organisms were able to synthesize antioxidant compounds. DPPH assay showed 20% of the organisms to reach a antioxidant zone of 1 cm and 8.3% of the strains more than 3 cm. Pseudomonas koreensis (JX915782) a Sargassum associated yellowish brown pigmented bacteria have better activity than known commercial antioxidant butylated hydroxytoluene (BHT) against DPPH scavenging. Serratia rubidaea (JX915783), an associate of Ulva sp. and Pseudomonas argentinensis (JX915781) an epiphyte of Chaetomorpha media, were also contributed significantly towards ABTS (7.2% ± 0.03 to 15.2 ± 0.09%; 1.8% ± 0.01 to 15.7 ± 0.22%) and FRAP (1.81 ± 0.01 to 9.35 ± 0.98; 7.97 ± 0.12 to 18.70 ± 1.84 μg/mL of AsA Eq.) respectively. 16S rRNA gene sequence analysis revealed bacteria that have higher antioxidant activity belongs to a bacterial class Gammaproteobacteria. Statistical analysis of phenolic contents in relation with other parameters like DPPH, ABTS, reducing power and FRAP are well correlated (p < 0.05). Results obtained from the current study inferred that the seaweed associated pigmented bacteria have enormous potential on antioxidant compounds and need to be extracted in a larger way for clinical applications.

Composition, anti-quorum sensing and antimicrobial activity of essential oils from Lippia alba

Many Gram-negative pathogens have the ability to produce N-acylhomoserine lactones (AHLs) as signal molecules for quorum sensing (QS). This cell-cell communication system allows them to coordinate gene expression and regulate virulence. Strategies to inhibit QS are promising for the control of infectious diseases or antibiotic resistant bacterial pathogens. The aim of the present study was to evaluate the anti-quorum sensing (anti-QS) and antibacterial potential of five essential oils isolated from Lippia alba on the Tn-5 mutant of Chromobacterium violaceum CV026, and on the growth of the gram-positive bacteria S. aureus ATCC 25923. The anti-QS activity was detected through the inhibition of the QS-controlled violacein pigment production by the sensor bacteria. Results showed that two essential oils from L. alba, one containing the greatest geranial:neral and the other the highest limonene:carvone concentrations, were the most effective QS inhibitors. Both oils also had small effects on cell growth. Moreover, the geranial/neral chemotype oil also produced the maximum zone of growth inhibition against S. aureus ATCC 25923. These data suggest essential oils from L. alba have promising properties as QS modulators, and present antibacterial activity on S. aureus.

Morphology and mycelial growth rate of Pleurotus spp. strains from the Mexican mixtec region

Two native Pleurotus spp. strains (white LB-050 and pale pink LB-051) were isolated from rotten tree trunks of cazahuate (Ipomoea murucoides) from the Mexican Mixtec Region. Both strains were chemically dedikaryotized to obtain their symmetrical monokaryotic components (neohaplonts). This was achieved employing homogenization time periods from 60 to 65 s, and 3 day incubation at 28 °C in a peptone-glucose solution (PGS). Pairing of compatible neohaplonts resulted in 56 hybrid strains which were classified into the four following hybrid types: (R1-n xB1-n, R1-n xB2-1, R2-n xB1-n and R2-n xB2-1). The mycelial growth of Pleurotus spp. monokaryotic and dikaryotic strains showed differences in texture (cottony or floccose), growth (scarce, regular or abundant), density (high, regular or low), and pigmentation (off-white, white or pale pink). To determine the rate and the amount of mycelium growth in malt extract agar at 28 °C, the diameter of the colony was measured every 24 h until the Petri dish was completely colonized. A linear model had the best fit to the mycelial growth kinetics. A direct relationship between mycelial morphology and growth rate was observed. Cottony mycelium presented significantly higher growth rates (p < 0.01) in comparison with floccose mycelium. Thus, mycelial morphology can be used as criterion to select which pairs must be used for optimizing compatible-mating studies. Hybrids resulting from cottony neohaplonts maintained the characteristically high growth rates of their parental strains with the hybrid R1-n xB1-n being faster than the latter.

Improvement of submerged culture conditions to produce colorants by Penicillium purpurogenum

Safety issues related to the employment of synthetic colorants in different industrial segments have increased the interest in the production of colorants from natural sources, such as microorganisms. Improved cultivation technologies have allowed the use of microorganisms as an alternative source of natural colorants. The objective of this work was to evaluate the influence of some factors on natural colorants production by a recently isolated from Amazon Forest, Penicillium purpurogenum DPUA 1275 employing statistical tools. To this purpose the following variables: orbital stirring speed, pH, temperature, sucrose and yeast extract concentrations and incubation time were studied through two fractional factorial, one full factorial and a central composite factorial designs. The regression analysis pointed out that sucrose and yeast extract concentrations were the variables that influenced more in colorants production. Under the best conditions (yeast extract concentration around 10 g/L and sucrose concentration of 50 g/L) an increase of 10, 33 and 23% respectively to yellow, orange and red colorants absorbance was achieved. These results show that P. purpurogenum is an alternative colorants producer and the production of these biocompounds can be improved employing statistical tool.

A case of extensive chromoblastomycosis from North India

A case of extensive chromoblastomycosis of the right leg and thigh with verruciform to nodular lesions evolving rapidly over five years duration is reported. The diagnosis was confirmed by visualizing pathognomonic pigmented muriform bodies with unique septate hyphae and mycological culture yielding Fonsecaea pedrosoi.