Protein Adsorption Performance of a Novel Functionalized Cellulose-Based Polymer.

Dicarboxymethyl cellulose (DCMC) was synthesized and tested for protein adsorption. The prepared polymer was characterized by inductively coupled plasma atomic emission spectrometry (ICP-AES), attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR) and solid state nuclear magnetic resonance (ssNMR) to confirm the functionalization of cellulose. This work shows that protein adsorption onto DCMC is charge dependent. The polymer adsorbs positively charged proteins, cytochrome C and lysozyme, with adsorption capacities of 851 and 571 mg g-1, respectively. In both experiments, the adsorption process follows the Langmuir adsorption isotherm. The adsorption kinetics by DCMC is well described by the pseudo second-order model, and adsorption equilibrium was reached within 90 min. Moreover, DCMC was successfully reused for five consecutive adsorption-desorption cycles, without compromising the removal efficiency (98-99%).

DCMC as a Promising Alternative to Bentonite in White Wine Stabilization. Impact on Protein Stability and Wine Aromatic Fraction.

Protein haze in white wine is one of the most common non-microbial defects of commercial wines, with bentonite being the main solution utilized by the winemaking industry to tackle this problem. Bentonite presents some serious disadvantages, and several alternatives have been proposed. Here, an alternative based on a new cellulose derivative (dicarboxymethyl cellulose, DCMC) is proposed. To determine the efficiency of DCMC as a bentonite alternative, three monovarietal wines were characterized, and their protein instability and content determined by a heat stability test (HST) and the Bradford method, respectively. The wines were treated with DCMC to achieve stable wines, as shown by the HST, and the efficacy of the treatments was assessed by determining, before and after treatment, the wine content in protein, phenolic compounds, sodium, calcium, and volatile organic compounds (VOCs) as well as the wine pH. DCMC applied at dosages such as those commonly employed for bentonite was able to reduce the protein content in all tested wines and to stabilize all but the Moscatel de Setúbal varietal wine. In general, DCMC was shown to induce lower changes in the wine pH and phenolic content than bentonite, reducing the wine calcium content. Regarding which VOCs are concerned, DCMC produced a general impact similar to that of bentonite, with differences depending on wine variety. The results obtained suggest that DCMC can be a sustainable alternative to bentonite in protein white wine stabilization.

Playing the blues, the greens and the reds with cellulose-based structural colours.

Structural vivid colours can arise from the interference of light reflected from structures exhibiting periodicity on scales in the range of visible wavelengths. This effect is observed with light reflected from cell-walls of some plants and exoskeletons of certain insects. Sometimes the colour sequence observed for these structures consists of nearly circular concentric rings that vary in colour from Red, Orange, Yellow, Green, Cyan to Blue, from the periphery to the centre, similarly to the colour scheme sequence observed for the rainbow (ROYGB). The sequence of colours has been found for solid films obtained from droplets of aqueous cellulose nanocrystals (CNCs) suspensions and attributed to a "coffee ring" effect. In this work, coloured lyotropic solutions and solid films obtained from a cellulose derivative in the presence of trifluoroacetic acid (TFA), which acts as a "reactive solvent", are revisited. The systems were investigated with spectroscopy, using circularly and linearly polarised light, coupled with a polarised optical microscope (POM) and scanning electron microscopy (SEM). The lyotropic cholesteric liquid crystalline solutions were confined in capillaries to simplify 1D molecular diffusion along the capillary where an unexpected sequence of the structural colours was observed. The development and reappearance of the sequence of vivid colours seem consistent with the reaction-diffusion of the "reactive solvent" in the presence of the cellulosic chains. The strong TFA acts as an auto-catalyst for the chemical reaction between TFA and the hydroxyl groups, existing along the cellulosic chain, and diffuses to the top and bottom along the capillaries, carrying dissolved cellulosic chains. Uncovering the precise mechanism of colour sequence and evolution over time in cellulosic lyotropic solutions has important implications for future optical/sensors applications and for the understanding of the development of cellulose-based structures in nature.

A Novel Cellulose-Based Polymer for Efficient Removal of Methylene Blue.

A novel cellulose-based cross-linked polymer, dicarboxymethyl cellulose (DCMC), has been synthesized and used for methylene blue (MB) removal. Inductively coupled plasma atomic emission spectrometry (ICP-AES), Fourier-transform infrared spectroscopy (FTIR), nitrogen porosimetry, and optical microscopy were employed to characterize the structure of the cellulose-based adsorbent. The number of carboxylate groups per gram of polymer (CG) was calculated with sodium content determined by ICP-AES. Systematic equilibrium and kinetic adsorption studies were performed to assess the polymer suitability for dye removal. The effect of pH on its adsorption capacity was also studied and the equilibrium adsorption data was analyzed using Langmuir, Freundlich, and Sips isotherms. At pH = 3, the adsorption isotherms followed the Langmuir model with a maximum adsorption capacity of 887.6 mg/g. At pH = 6.4, the adsorption isotherms produced S-shape curves and were best fitted with the Sips model. The maximum MB uptake increased to 1354.6 mg/g. Pseudo first-order and second-order models were used to fit the kinetic data. A pseudo second-order kinetic model provided the best correlation for the adsorption of MB onto DCMC. Adsorption coupled with membrane filtration achieved 95% methylene blue removal and DCMC can be successfully regenerated and reused in consecutive experiments.

Freshwater fishes of the Bahia State, Northeastern Brazil / Peixes de água doce do Estado da Bahia, Nordeste do Brasil

Abstract: This work was carried out from the assessment of the conservation status of the freshwater ichthyofauna from Bahia State. The inventory data and species distribution were obtained from the specialized scientific literature and representative ichthyological collections. A total of 281 native species was recorded in Bahia State, distributed in the Northeastern Mata Atlantica (NMA) and São Francisco (SFR) freshwater ecoregions. There was a larger number of species in the NMA (187 spp.), composed by several coastal basins, than in the SFR (134 spp.), composed by São Francisco river basin. Among the 30 families recorded, Characidae and Rivulidae were the most representative, with 53 and 48 species, respectively. The conservation status of 214 species was assessed and 33 of them (15%) were included in the IUCN threat categories. Of these, 11 species were classified as vulnerable (VU), 12 as endangered (EN), and 10 as critically endangered (CR). Most threatened species (n = 14) belongs to the family Rivulidae. The larger number of threatened species in the NMA: (n = 23) is mainly related to the high endemism of restricted-range species associated with the human occupation impacts along the coastal regions. In the SFR, most of threatened species are annual killifishes, which are locally disappearing due to increasing degradation of their temporary habitats.

Resumo: Este trabalho foi realizado a partir da avaliação do estado de conservação da ictiofauna de água doce do Estado da Bahia. Os dados de inventário e distribuição das espécies foram obtidos a partir da literatura científica especializada e de coleções ictiológicas representativas. Um total de 281 espécies nativas foi registrado no Estado da Bahia, distribuídas nas ecorregiões de água doce Mata Atlântica Nordeste (NMA) e São Francisco (SFR). A riqueza de espécies foi maior na NMA (187 spp.), composta por diversas bacias costeiras, do que na SFR (134 spp.), composta pela bacia do rio São Francisco. Das 30 famílias registradas, as mais representativas foram Characidae e Rivulidae, com 53 e 48 espécies, respectivamente. O estado de conservação de 214 espécies foi avaliado e 33 (15%) destas foram classificadas em alguma categoria de ameaça da IUCN. Destas, 11 foram classificadas como vulneráveis (VU), 12 em perigo (EN) e 10 criticamente em perigo (CR). A maioria das espécies ameaçadas (n = 14) pertence à família Rivulidae. O elevado número de espécies ameaçadas na NMA: (n = 23) está associado ao alto endemismo das espécies com distribuição restrita e aos impactos da ocupação humana ao longo da região costeira. Na SFR, a maioria das espécies ameaçadas é de peixes anuais, que estão localmente desaparecendo devido à degradação crescente de seus habitats temporários.

Sulfur dioxide induced aggregation of wine thaumatin-like proteins: Role of disulfide bonds.

Aggregation of heat unstable wine proteins is responsible for the economically and technologically detrimental problem called wine protein haze. This is caused by the aggregation of thermally unfolded proteins that can precipitate in bottled wine. To study the influence of SO2 in this phenomenon, wine proteins were isolated and thaumatins were identified has the most prone to aggregate in the presence of this compound. Isolated wine thaumatins aggregation was followed by dynamic light scattering (DLS), circular dichroism (CD), fluorescence spectroscopy and size exclusion chromatography (SEC). Our experimental results demonstrate that protein thermal unfolding after exposure of the protein to 70 °C does not present differences whether SO2 is present or not. Conversely, when the protein solution is cooled to 15 °C (after heat stress) significant analytical changes can be observed between samples with and without SO2. A remarkable change of circular dichroism spectra in the region 220-230 nm is observed (which can be related to S-S torsion angles), as well as an increase in tryptophan fluorescence intensity (absence of fluorescence quenching by S-S bonds). Formation of covalently-linked dimeric and tetrameric protein species were also detected by SEC. The ability to dissolve the aggregates with 8 M urea seems to indicate that hydrophobic interactions are prevalent in the formed aggregates. Also, the reduction of these aggregates with tris (2-carboxyethyl) phosphine (TCEP) to only monomeric species reveals the presence of intermolecular S-S bonds.

Is caffeic acid, as the major metabolite present in Moscatel wine protein haze hydrolysate, involved in protein haze formation?

This work was conducted to identify the major low molecular weight compounds present in the wine precipitate and to assess their potential contribution to wine protein haze formation. The heat-induced protein precipitate from a white Moscatel of Alexandria wine was subjected to alkaline hydrolysis. The major compound present was found to be caffeic acid among other minor, unidentified compounds. Caffeic acid was identified by both UV-vis and 1H NMR spectra. The concentration of caffeic acid in the original wine sample was 1.1mg/L, as quantified by HPLC following SPE. Heat stability tests were performed using two different concentrations of caffeic acid and its ester caftaric acid in model wine solution added of isolated wine protein. No correlation was found between caffeic or caftaric acid concentration and haze forming potential in wine model solution. This work shows that caffeic acid is present in considerable amounts in Moscatel wine protein haze, but does not seem to trigger or participate in the protein aggregation mechanism upon heating.

Molecular Identification and Traceability of Illegal Trading in Lignobrycon myersi (Teleostei: Characiformes), a Threatened Brazilian Fish Species, Using DNA Barcode.

Lignobrycon myersi is a threatened freshwater fish species and endemic of a few coastal rivers in northeastern Brazil. Even though the Brazilian laws prohibit the fisheries of threatened species, L. myersi is occasionally found in street markets, being highly appreciated by local population. In order to provide a reliable DNA barcode dataset for L. myersi, we compared mitochondrial sequences of cytochrome c oxidase subunit I (COI) from fresh, frozen, and salt-preserved specimens. Phylogenetically related species (Triportheus spp.) and other fish species (Astyanax fasciatus) commonly mixed with L. myersi in street markets were also included to test the efficiency of molecular identification. In spite of the differences in conservation processes and advanced deterioration of some commercial samples, high-quality COI sequences were obtained and effective in discriminating L. myersi specimens. In addition, while populations from Contas and Almada River basins seem to comprise a single evolutionary lineage, the specimens from Cachoeira River were genetically differentiated, indicating population structuring. Therefore, DNA barcoding has proved to be useful to trace the illegal trading of L. myersi and to manage threatened populations, which should focus on conservation of distinct genetic stocks and mitigation on human impacts along their range.

Is Nematocharax (Actinopterygii, Characiformes) a monotypic fish genus?

The combination of DNA barcodes and geometric morphometrics is useful to discriminate taxonomically controversial species, providing more precise estimates of biodiversity. Therefore, our goal was to assess the genetic and morphometric diversity in Nematocharax, a controversial monotypic and sexually dimorphic genus of Neotropical fish, based on sequencing of cytochrome c oxidase subunit I (COI) and morphometric analyses in seven populations of N. venustus from coastal rivers in Brazil. The average pairwise intrapopulation divergence in COI ranged from 0 to 2.2%, while the average pairwise interpopulation divergence varied from 0 to 7.5%. The neighbour-joining (NJ) tree resulted in five genetic groups (bootstrap ≥ 97%), which correspond to the five clusters delimited by the BIN System, GMYC, and bPTP, indicating that there might be at least five species (or OTUs) within Nematocharax. Morphometric differences among these genetic lineages were also identified. Apparently, sexual selection, restricted dispersal, and geographic isolation might have acted synergistically to cause the evolutionary split of populations. These data challenge the current view that Nematocharax is a monotypic genus inasmuch as evolutionarily significant units or even distinguished species were identified. Therefore, we recommend that the highly impacted coastal basins in northeastern Brazil should be prioritized in conservation plans.

The challenging SO2-mediated chemical build-up of protein aggregates in wines.

Despite the extensive research performed during the last decades, the multifactorial mechanism responsible for white wine protein haze formation is not fully characterized. A model is proposed, which is essentially based on two postulates: the experimental identification of sulfur dioxide as the non-proteinaceous factor, and the inference from reliable data available in the literature of the dynamic chemistry played by wine protein sulfhydryl groups. Unlike other reducing agents, addition of SO2 to must/wine upon heating cleaves intraprotein disulfide bonds, hinders thiol-disulfide exchange during protein interactions, and leads to formation of novel interprotein disulfide bonds. These bonds are ultimately responsible for wine protein aggregation following a nucleation-growth kinetic model, as shown by Dynamic Light Scattering experiments. The model was tested in wine model solution (using total and fractionated wine proteins) and validated under real wine conditions. The results achieved may open the way to develop techniques that will find wide application in the wine industry.

Ictiofauna do Ribeirão Limoeiro, Bacia do Rio Cachoeira, BA / Ichthyofauna of the Ribeirão Limoeiro, Cachoeira River Basin, BA

Os riachos da Bacia do Leste caracterizam-se por serem pequenos, pouco complexos e com ictiofauna endêmica decorrente do isolamento geográfico. Neste contexto, foi realizado um estudo da distribuição das espécies e estrutura da comunidade de peixes do Ribeirão Limoeiro, BA ao longo de um gradiente espacial no período de um ano, utilizando-se a pesca elétrica como método de coleta. Foram coletadas 21 espécies totalizando 2264 indivíduos em quatro pontos: dois próximos da cabeceira (P1A e P1M), um no médio curso (P2) e outro próximo à sua foz (P3). Characiformes e Siluriformes foram as ordens mais representativas dentre as quatro registradas. Algumas espécies ocorreram exclusivamente na cabeceira (Astyanax sp. e Trichomycterus cf. bahianus) e outras próximo da foz (Leporinus sp. e Callichthys callichthys). Por outro lado, Characidium zebra, Parotocinclus cf. cristatus, Poecilia vivipara, Astyanax sp.1, Rhamdia sp. e Poecilia reticulata ocorreram em todos os pontos amostrados. Foi coletada uma espécie com "status" de vulnerável (Nematocharax venustus) e duas exóticas (Tilapia rendalli e Poecilia reticulata). Quanto à estrutura da comunidade, os valores dos índices de riqueza de "Margalef" e de diversidade de "Shannon" foram significativamente maiores no ponto P3, por outro lado, este ponto apresentou valores significativamente menores do índice de dominância de "Berger-Parker". O ponto com vegetação ripária preservada (P1M) apresentou menor valor médio da temperatura da água e os pontos de cabeceira (P1A e P1M) apresentaram os maiores valores médios de oxigênio dissolvido e velocidade superficial. Condutividade, largura e profundidade médias aumentaram da cabeceira para a foz. Vários resultados encontrados estão de acordo com a literatura atual que trata de ecologia de comunidades de peixes de riachos neotropicais.

The streams of the Eastern Basin are characterized by being small, somewhat complex and endemic fish fauna due to geographical isolation. In this context, a study of species distribution and community structure of stream fish Limoeiro, BA along a spatial gradient in one year, using electrofishing as the collection method. Twenty one fish species were collected totalizing 2264 specimens in four points: two points near the head (P1A and P1M), one in the middle course (P2) and another near the mouth (P3). Characiformes and Siluriformes were the orders more important among the four registered. Some species occurred exclusively at the head (Astyanax sp. and Trichomycterus cf. bahianus) and other near the mouth (Leporinus sp. and Callichthys callichthys). On the other hand, Characidium zebra, Parotocinclus cf. cristatus, Poecilia vivipara, Astyanax sp.1, Rhamdia sp. and Poecilia reticulata occurred all sampling points. Was collected one specie the "status" of vulnerable (Nematocharax venustus) and two exotics (Tilapia rendalli and Poecilia reticulata). About the community structure, the values of the index of richness of "Margalef" and of the index of diversity of "Shannon" were greater in this point P3, then this point were significantly lower value of "Berger-Parker" dominance index. The point with riparian vegetation preserved (P1M) showed a lower average water temperature and the points near the head (P1A and P1M) showed the highest values of dissolved oxygen and surface velocity. Conductivity, width and depth of the medium increased toward the mouth. Several results are in accordance with the current literature dealing with community ecology of neotropical stream fish.

Diet of two serrasalmin species, Pygocentrus piraya and Serrasalmus brandtii (Teleostei: Characidae), along a stretch of the rio de Contas, Bahia, Brazil

Serrasalmus brandtii and Pygocentrus piraya are two common piranha species in the Barragem da Pedra Reservoir, rio de Contas. In order to identify the diet composition of the two species, monthly collections were performed at three sites between May 2001 and April 2003, using two gill nets of different mesh sizes cast at the beginning of the day and visited after 6, 12 and 24 h. The qualitative composition of the diet was analyzed by determining the frequency of occurrence. Comparison of the two species showed a higher relative abundance of S. brandtii (151) compared to P. piraya (55). The food items most frequently found in the stomachs of the two species were fins, fish and shrimp. Serrasalmus brandtii showed a greater feeding plasticity than P. piraya.

Serrasalmus brandtii e Pygocentrus piraya são duas espécies de piranhas comuns no reservatório da Barragem da Pedra, rio de Contas. Com o objetivo de identificar a composição da dieta das duas espécies, foram realizadas coletas mensais em três pontos no período de maio de 2001 a abril de 2003, tendo em cada ponto duas redes de espera com malhas distintas, colocadas no início do dia e visitadas após 6, 12 e 24 horas. A composição qualitativa da dieta foi analisada com uso do método de freqüência de ocorrência. A comparação realizada entre as duas espécies descritas revelou haver uma maior abundância relativa de S. brandtii (151) em relação à P. piraya (55). Os resultados indicaram que os itens: nadadeira, peixes e camarões foram os itens encontrados com maior freqüência nos estômagos de ambas as espécies. Serrasalmus brandtii mostrou uma maior plasticidade alimentar do que a P. piraya.

Toxicidade de extratos de Piper nigrum, piperina e piperamidas para o diplópodo Orthoporus fuscipes em condições de laboratório / Toxicity of extracts from Piper nigrum, piperine and piperamides to the millipede Orthoporus fuscipes under laboratory conditions

The toxicity of an ethanolic extract of black pepper (Piper nigrum), of piperine and of the synthetic amides adamantylpiperamide, sopentylpiperamide and diisopropylpiperamide was evaluated using the millipede Orthoporus fuscipes. For the experiments, the test organism was exposed to a diet of wheat bran and sugar (9:1) supplemented with the test substance in solution and mortality was monitored over a period of 17 days. Mortality was 100 percent for 0.3 g of the ethanolic extract of black pepper fruits and for diisopropylpiperamide after 4 and 14 days of exposure, respectively. Piperine at a concentration of 0.3 g resulted in 70 percent mortality after 4 days and remained at this rate until the end of the exposure period. Thus, among the compounds tested the ethanolic extract of black pepper fruit was the most effective and most promising for the control of Orthoporus fuscipes populations since it promoted a higher rate of mortality of the test organism within a shorter period of exposure.

A toxicidade do extrato etanólico da pimenta-do-reino (Piper nigrum), da piperina e amidas sintéticas: adamantilpiperamida, isopentilpiperamida e diisopropilpiperamida foi avaliada para o diplópodo Orthoporus fuscipes. Os experimentos consistiram na exposição dos organismos-teste a uma dieta de farelo de trigo e açúcar (9:1) a qual foi adicionada a substância teste em solução observando-se a mortalidade por um período de 17 dias. Verificou-se na dose contendo 0,3 g do extrato etanólico de frutos da pimenta-do-reino e da diisopropilpiperamida, 100 por cento de mortalidade após 04 e 14 dias de exposição, respectivamente. A piperina na concentração de 0,3 g causou 70 por cento de mortalidade após 4 dias, mantendo-se até o final do período de exposição. Dessa forma, dentre os compostos testados, o extrato etanólico do fruto da pimenta-do-reino foi considerado o mais eficiente e promissor no controle de populações de Orthoporus fuscipes, pois foi o que promoveu maior porcentagem de exposição.

The air-breathing cycle of Hoplosternum littorale (Hancock, 1828)(Siluriformes: Callichthyidae)

Hoplosternum littorale is a continuous air breather, which uses a portion of its intestine to extract oxygen from inspired air. Its air-breathing behavior occurs in four phases: 1) ascent to the water surface; 2) mouth emergence with expansion of the oral cavity for air inspiration; 3) downward swimming and oral cavity compression resulting in air swallowing and the expiration of old air from the anus; 4) return to bottom. The time required to complete the air-breathing cycle was significantly shorter for small fish compared to large fish.

Hoplosternum littorale é um peixe de respiração aérea contínua que utiliza parte de seu intestino para a extração do oxigênio do ar. Este comportamento de respiração aérea realiza-se em quatro etapas: 1) Subida para a superfície da água; 2) Emergência da boca com a simultânea expansão da cavidade oral e inspiração; 3) Giro do corpo para baixo com compressão da cavidade oral e expiração do ar pelo ânus; 4) Retorno ao fundo. O tempo necessário para a realização do ciclo respiratório aéreo completo foi significativamente mais curto em indivíduos de menor tamanho quando comparados aos de maior massa corpórea.

Effects of deltamethrin pyrethroid on the respiratory metabolism of the neotropical spirostreptid millipedes Gymnostreptus olivaceus and Plusioporus setiger

The effects of deltamethrin on the respiratory metabolism of Gymnostreptus olivaceus and Plusioporus setiger were investigated. Acetone solutions corresponding to half the LD50 values, i.e., 20 mg.g-1 for G. olivaceus and 4.40 mg.g-1 for P. setiger, were used. Metabolism was determined with a Warburg respirometer at 25ºC. Respirometric measurements were performed 1, 3 and 6 hours after administration of the pyrethroid to the same groups of millipedes. After 24 hours, daily respirometric measurements lasting 1 hour each were made on different millipede groups for a period of 10 days. Significant differences were detected only between the groups treated with the pyrethroid and the two control groups. In G. olivaceus, respiratory rates increased by about 1.65-fold compared to normal immediately after administration of the pyrethroid, followed by a gradual decrease up to 72 hours and a return to normal levels thereafter. In P. setiger the increase was about 1.1-fold compared to normal, with a decrease up to 96 hours and a return to normal thereafter. Although increased oxygen consumption was observed, a detoxification process occurred in both species, so that the possible metabolism of the pyrethroid may justify the low toxicity of deltamethrin for G. olivaceus and P. setiger

Consideraçöes para elaboraçäo do código sanitário municipal / Considerations for elaboration of municipal sanitary code

O artigo apresenta algumas consideraçöes para os municípios do Estado de Mato Grosso, elaborarem seus códigos sanitários municipais, previsto pela Constituiçäo do Estado, e nas Leis Orgânicas Municipais

Projeto de cooperaçäo técnica pró-organizaçäo dos sistemas municipais de saúde / Technical cooperation project for the organization of the municipal health systems

O projeto de cooperaçäo técnica para a organizaçäo dos Sistemas Municipais de Sáude é resultante de um convênio celebrado entre a Secretaria Estadual de Saúde-MT, a Associaçäo Matogrossense dos municípios e a Universidade Federal de Mato Grosso. Este projeto surgiu da necessidade de fornecer subsídios técnicos e operacionais às Secretarias Municipais de Saúde no processo de descentralizaçäo dos serviços de saúde