Gene expression and immunolocalization of chitin deacetylase BmCDA2 in silkworm / 生物工程学报

Deacetylation of chitin is closely related to insect development and metamorphosis. Chitin deacetylase (CDA) is a key enzyme in the process. However, to date, the CDAs of Bombyx mori (BmCDAs), which is a model Lepidopteran insect, were not well studied. In order to better understand the role of BmCDAs in the metamorphosis and development of silkworm, the BmCDA2 which is highly expressed in epidermis was selected to study by bioinformatics methods, protein expression purification and immunofluorescence localization. The results showed that the two mRNA splicing forms of BmCDA2, namely BmCDA2a and BmCDA2b, were highly expressed in the larval and pupal epidermis, respectively. Both genes had chitin deacetylase catalytic domain, chitin binding domain and low density lipoprotein receptor domain. Western blot showed that the BmCDA2 protein was mainly expressed in the epidermis. Moreover, fluorescence immunolocalization showed that BmCDA2 protein gradually increased and accumulated with the formation of larval new epidermis, suggesting that BmCDA2 may be involved in the formation or assembly of larval new epidermis. The results increased our understandings to the biological functions of BmCDAs, and may facilitate the CDA study of other insects.

Extraction of chitin from edible crab shells of Callinectes sapidus and comparison with market purchased chitin / Extração de quitina de cascas de caranguejo comestíveis de Callinectes sapidus e comparação com quitina adquirida no mercado

Chitin and its derived products have immense economic value due to their vital role in various biological activities as well as biomedical and industrial application. Insects, microorganism and crustaceans are the main supply of chitin but the crustaceans shell like shrimp, krill, lobsters and crabs are the main commercial sources. Chitin content of an individual varies depending on the structures possessing the polymer and the species. In this study edible crabs’ shells (Callinectes sapidus) were demineralized and deproteinized resulting in 13.8% (dry weight) chitin recovery from chitin wastes. FTIR and XRD analyses of the experimental crude as well as purified chitins revealed that both were much comparable to the commercially purchased controls. The acid pretreatment ceded 54g of colloidal chitin that resulted in 1080% of the crude chitin. The colloidal chitin was exploited for isolation of eighty five chitinolytic bacterial isolates from different sources. Zone of clearance was displayed by the thirty five isolates (41.17%) succeeding their growth at pH 7 on colloidal chitin agar medium. Maximum chitinolytic activity i.e. 301.55 U/ml was exhibited by isolate JF70 when cultivated in extracted chitin containing both carbon and nitrogen. The study showed wastes of blue crabs can be utilized for extraction of chitin and isolation of chitinolytic bacteria that can be used to degrade chitin waste, resolve environmental pollution as well as industrial purpose.

A quitina e seus produtos derivados têm imenso valor econômico devido ao seu papel vital em várias atividades biológicas, bem como em aplicações biomédicas e industriais. Insetos, microrganismos e crustáceos são o principal suprimento de quitina, mas a casca dos crustáceos como camarão, krill, lagosta e caranguejo são as principais fontes comerciais. O conteúdo de quitina de um indivíduo varia dependendo das estruturas que possuem o polímero e da espécie. Neste estudo, as cascas de caranguejos comestíveis (Callinectes sapidus) foram desmineralizadas e desproteinizadas, resultando em 13,8% (peso seco) de recuperação de quitina a partir de resíduos de quitina. As análises de FTIR e XRD do bruto experimental, bem como das quitinas purificadas, revelaram que ambas eram muito comparáveis aos controles adquiridos comercialmente. O pré-tratamento com ácido cedeu 54 g de quitina coloidal que resultou em 1.080% da quitina bruta. A quitina coloidal foi analisada para isolamento de 85 isolados bacterianos quitinolíticos de diferentes fontes. A zona de eliminação foi exibida pelos 35 isolados (41,17%) que sucederam seu crescimento a pH 7 em meio de ágar de quitina coloidal. A atividade quitinolítica máxima, ou seja, 301,55 U / ml, foi exibida pelo isolado JF70 quando cultivado em quitina extraída contendo carbono e nitrogênio. O estudo mostrou que resíduos de caranguejos azuis podem ser utilizados para extração de quitina e isolamento de bactérias quitinolíticas que podem ser usadas para degradar resíduos de quitina, resolver a poluição ambiental e também para fins industriais.

Extraction of chitin from edible crab shells of Callinectes sapidus and comparison with market purchased chitin

Abstract Chitin and its derived products have immense economic value due to their vital role in various biological activities as well as biomedical and industrial application. Insects, microorganism and crustaceans are the main supply of chitin but the crustaceans shell like shrimp, krill, lobsters and crabs are the main commercial sources. Chitin content of an individual varies depending on the structures possessing the polymer and the species. In this study edible crabs shells (Callinectes sapidus) were demineralized and deproteinized resulting in 13.8% (dry weight) chitin recovery from chitin wastes. FTIR and XRD analyses of the experimental crude as well as purified chitins revealed that both were much comparable to the commercially purchased controls. The acid pretreatment ceded 54g of colloidal chitin that resulted in 1080% of the crude chitin. The colloidal chitin was exploited for isolation of eighty five chitinolytic bacterial isolates from different sources. Zone of clearance was displayed by the thirty five isolates (41.17%) succeeding their growth at pH 7 on colloidal chitin agar medium. Maximum chitinolytic activity i.e. 301.55 U/ml was exhibited by isolate JF70 when cultivated in extracted chitin containing both carbon and nitrogen. The study showed wastes of blue crabs can be utilized for extraction of chitin and isolation of chitinolytic bacteria that can be used to degrade chitin waste, resolve environmental pollution as well as industrial purpose.

Resumo A quitina e seus produtos derivados têm imenso valor econômico devido ao seu papel vital em várias atividades biológicas, bem como em aplicações biomédicas e industriais. Insetos, microrganismos e crustáceos são o principal suprimento de quitina, mas a casca dos crustáceos como camarão, krill, lagosta e caranguejo são as principais fontes comerciais. O conteúdo de quitina de um indivíduo varia dependendo das estruturas que possuem o polímero e da espécie. Neste estudo, as cascas de caranguejos comestíveis (Callinectes sapidus) foram desmineralizadas e desproteinizadas, resultando em 13,8% (peso seco) de recuperação de quitina a partir de resíduos de quitina. As análises de FTIR e XRD do bruto experimental, bem como das quitinas purificadas, revelaram que ambas eram muito comparáveis aos controles adquiridos comercialmente. O pré-tratamento com ácido cedeu 54 g de quitina coloidal que resultou em 1.080% da quitina bruta. A quitina coloidal foi analisada para isolamento de 85 isolados bacterianos quitinolíticos de diferentes fontes. A zona de eliminação foi exibida pelos 35 isolados (41,17%) que sucederam seu crescimento a pH 7 em meio de ágar de quitina coloidal. A atividade quitinolítica máxima, ou seja, 301,55 U / ml, foi exibida pelo isolado JF70 quando cultivado em quitina extraída contendo carbono e nitrogênio. O estudo mostrou que resíduos de caranguejos azuis podem ser utilizados para extração de quitina e isolamento de bactérias quitinolíticas que podem ser usadas para degradar resíduos de quitina, resolver a poluição ambiental e também para fins industriais.

Cicatrização da musculatura reto-abdominal em coelhos submetidos à laparorrafia com fios de sutura à base de quitosana, categute cromado e poliglactina 910 / [Healing of the rectus abdominis muscle in rabbits submitted to laparorrhaphy with suture-based chitosan, chromic catgut and polyglactin 910]

Objetivou-se, com este estudo, avaliar o processo de cicatrização da musculatura reto-abdominal em coelhos submetidos à laparorrafia, utilizando-se o fio de sutura à base de quitosana, comparando-o aos fios de categute cromado e poliglactina 910. Foram utilizados 24 coelhos adultos, divididos aleatoriamente em quatro grupos: quitosana e categute 15 dias (QC-15dias), quitosana e categute 30 dias (QC-30 dias), quitosana e poliglactina 910 15 dias (QP-15 dias) e quitosana e poliglactina 910 30 dias (QP-30 dias). Cada grupo foi composto por seis coelhos, nos quais foram realizadas duas incisões, uma do lado direito e outra do lado esquerdo e, posteriormente, a laparorrafia, com o fio de quitosana de um lado e o categute cromado ou poliglactina 910 do outro. Realizou-se análise clínico-cirúrgica, histológica e avaliação de achados de necropsia, além de testes de citotoxicidade e de mecânica no fio de quitosana. Ele apresentou baixa resistência mecânica e citotóxica. O fio de quitosana não proporcionou uma cicatrização satisfatória em coelhos, pois desencadeou uma resposta inflamatória acentuada.(AU)

The objective of this study was to evaluate the healing process of the recto-abdominal muscles in rabbits submitted to laparorrhaphy using chitosan-based suture yarn, comparing it to chrome catgut and polyglactin 910 yarns. Twenty-four adult rabbits were divided in to four random groups: chitosan and polyglactin 910 15 days (QP-15 days) and chitosan and polyglactin 910 30 days (QC-30 days), chitosan and polyglactin 910 15 days (QP-15 days) QP-30 days). Each group consisted of six rabbits, in which two incisions were made, one on the right side and one on the left side, and later the laparorraphy with the chitosan yarn on one side and chromed catgut or polyglactin 910 on the other. Clinical-surgical, histological and necropsy findings were evaluated, as well as cytotoxicity and mechanical tests on the chitosan wire. It presented low mechanical and cytotoxic resistance. Chitosan thread did not provide satisfactory healing in rabbits, as it triggered a marked inflammatory response.(AU)

Characterization and evaluation for wound healing of chitosan extracted from the exoskeleton of freshwater crab Potamonautes niloticus

The freshwater crab Potamonautes niloticus (Potamonautidae: Decapoda: Crustacea) is common in River Nile andits tributaries but has no commercial value as edible crab for human beings. Therefore, the present study aims toevaluate the role of chitosan extracted from its exoskeleton for wound healing process as a medical application. Thestructure of chitosan has been physically investigated by using fourier transformer infrared spectroscopy to reveal thevibrational frequencies of different structural functional groups, such as primary amine groups, hydroxyl groups andamide groups. The efficiency of the extracted chitosan was assessed by morphological and histological examinationof wound healing in albino rats. Sections of isolated wounds were stained with hematoxylin and eosin to evaluate thehistological changes during the wound healing process. Chitosan was yielded 30.64% from the crab shells and theresults of wound healing assessments showed that the chitosan treated group (Ch 1%) was more efficient and fasterthan other groups (Ch 2, 3%) versus control groups. Also, the total leucocyte counts showed shortened inflammatoryphase in chitosan-treated groups. The present results showed the efficiency of extracted chitosan in wound healingprocess and can be used in medical applications.

Benzophenyl urea insecticides – useful and eco-friendly options for insect pest control

Insecticides play a very important role in increasing production by protecting crops from destructive insect pests. But indiscriminate use of conventional and broad spectrum insecticides, leads to development of resistance, resurgence and environmental pollution. Therefore, it is necessary to select new, safe and less persistent products for ecofriendly and sustainable pest management. Benzophenyl urea based insecticides fit well in this aspect. These are basically inhibitors of the chitin synthesis in insects which make them strong candidate for the integrated pest management. Extensive research has been carried out on different aspects to assess the potentiality and environment friendliness of this group of insecticides. Thus, the aim of this review is to gather comprehensive information about benzophenyl urea insecticide related to its development, mode of action, bio-efficacy, environmental fate and eco-toxicity, which may be helpful for the researchers for future endeavour.

Biotechnological recovery of chitin from crustacean waste / Recuperación biotecnológica de quitina de residuos de crustáceos

Abstract Reviews on biotechnological recovery of chitin from crustacean waste and other sources are acknowledged in the present review. Most of the reviews conclude that although important results on chitin recovery have been achieved, there is still a need for better approaches to improve operational conditions of deproteinization and demineralization processes, such as time, carbon source, pH (initial and during fermentation), volume of inoculum, temperature, among others, in order to apply at industrial level, a bioprocess commercially and environmentally cost/effective viable. The present review aims to gather the most updated available information about research on biotechnological methods to recover chitin from crustacean waste, studied during the past 10 years, focussing on conditions applied to deproteinization (DP) and demineralization (DM), particularly on bioprocessing times and microbial species.

Resumen Revisiones sobre recuperación de quitina a partir de residuos de crustáceos y otras fuentes usando biotecnología son reconocidas en el presente artículo. La mayoría de las revisiones concluyen que aunque se han logrado resultados importantes en la recuperación de quitina, todavía existe la necesidad de mejorar las condiciones operativas de los procesos de desproteinización y desmineralización, tales como el tiempo, la fuente de carbono, el pH (inicial y durante la fermentación), el volumen de inóculo y la temperatura, entre otros, para aplicar a nivel industrial un bioproceso que sea comercial y ambientalmente costo-beneficio viable. La presente revisión tiene como objetivo reunir la información más actualizada disponible sobre la investigación en métodos biotecnológicos para recuperar la quitina de los residuos de crustáceos, estudiada durante los últimos 10 años, centrándose en las condiciones aplicadas a la desproteinización (DP) y la desmineralización (DM), particularmente en los tiempos de bioprocesamiento y las especies microbianas involucradas.

Chitosan level effects on fermentation profile and chemical composition of sugarcane silage / Efeitos de níveis de quitosana sobre o perfil fermentativo e a composição química da silagem de cana-de-açúcar

This study aimed to evaluate the effects of increasing levels of chitosan (CHI) on sugarcane fermentation profile and losses, chemical composition, and in situ degradation. Treatments were: 0, 1, 2, 4, and 8 g of CHI/kg of dry matter (DM). Twenty experimental silos (PVC tubing with diameter 28 cm and height 25 cm) were used. Sand (2 kg) was placed at the bottom of each silo to evaluate effluent losses, and silos were weighed 60 d after ensiling to calculate gas losses. Samples were collected from the center of the silo mass to evaluate silage chemical composition, in situdegradation, fermentation profile, and mold and yeast count. Data were analyzed as a completely randomized design, and the treatment effect was decomposed using polynomial regression. Chitosan linearly increased acetic acid and NH3-N concentration, while yeast and mold count, and ethanol concentration decreased. Intermediary levels of CHI (from 4.47 to 6.34 g/kg DM) showed the lower values of effluent, gas, and total losses. There was a quadratic effect of CHI on the content of non-fiber carbohydrates, neutral and acid detergent, and in situ DM degradation. The lowest fiber content was observed with levels between 7.01 and 7.47 g/kg DM, whereas the highest non-fiber carbohydrate content and in situ DM degradation were found with 6.30 and 7.17 g/kg DM of CHI, respectively. Chitosan linearly increased acetic acid and NH3-N concentration, whereas it linearly reduced ethanol concentration and count of yeast and mold. Thus, intermediary levels of CHI, between 4.47 and 7.47 g/kg of DM, decrease fermentation losses and improve the nutritional value of sugarcane silage.(AU)

Foram avaliados os efeitos do aumento dos níveis de quitosana (CHI) sobre o perfil e as perdas fermentativas, a composição química e degradação in situ da silagem de cana-de-açúcar. Os tratamentos foram: 0, 1, 2, 4 e 8 g de CHI / kg de matéria seca (MS). Foram utilizados vinte silos experimentais (tubos de PVC com 28 cm de diâmetro e 25 cm de altura). Areia (2 kg) foi adicionada na porção inferior de cada silo para avaliar as perdas por efluentes e os silos foram pesados 60 dias após a ensilagem para calcular as perdas por gases. Amostras foram coletadas do centro da massa do silo para avaliar a composição química, degradação in situ, perfil fermentativo e a contagem de fungos e leveduras da silagem. Os dados foram analisados como um delineamento inteiramente casualizado e o efeito do tratamento foi decomposto usando regressão polinomial. A CHI aumentou linearmente a concentração de ácido acético e N-NH3, enquanto diminuiu a contagem de leveduras e bolores e a concentração de etanol. Os níveis intermediários de CHI (de 4,47 a 6,34 g/kg MS) mostraram os menores valores de perdas por efluentes, gases e totais. Houve efeito quadrático da CHI sobre o teor de carboidratos não fibrosos, fibra em detergente neutro e ácido e sobre a degradação in situ da MS. Os menores teores de fibras foram observados com níveis de CHI entre 7,01 e 7,47 g/kg MS, enquanto que os maiores teores de carboidratos não fibrosos e degradação in situ da MS foram encontrados com 6,30 e 7,17 g/kg MS de CHI, repectivamente. A CHI aumentou linearmente as concentrações de ácido acético e N-NH3, enquanto reduziu linearmente a concentração de etanol e a contagem de fungos e leveduras. Desta forma, níveis intermediários de CHI, entre 4,47 e 7,47 g / kg de MS, diminuem as perdas fermentativas e melhoram o valor nutricional da silagem de cana-de-açúcar.(AU)

Susceptibility of soybean looper to lufenuron and spinosad / Susceptibilidade da lagarta falsa-medideira a lufenuron e espinosade

The soybean looper (Chrysodeixis includens) is an important defoliation pest in crops such as soybean and cotton in Brazil. Its main control tactic is chemical insecticides. Considering the importance of chemical control for this pest, monitoring the susceptibility of C. includens populations is strategic for an efficient Insect Resistance Management. Therefore, the objective of this study was to evaluate the susceptibility levels of C. includens populations in the state of Mato Grosso - Brazil to lufenuron and spinosad. Seven populations were collected in soybean fields around the state. For the bioassays, early L3 larvae were exposed to insecticides using the diet-overlay method. Although the compounds have distinct modes of action, Tangará da Serra population had the highest resistance ratios for lufenuron (11.62) and spinosad (7.84), compared to laboratory population (susceptibility reference). Even with low resistance levels, it is necessary to maintain regional monitoring of C. includens susceptibility to the evaluated insecticides, as well as to extend the range of molecules monitored.(AU)

A lagarta falsa-medideira (Chrysodeixis includens) é uma importante praga desfolhadora em culturas como soja e algodão no Brasil e seu principal método de controle é o uso de inseticidas químicos. Considerando a importância do controle químico para essa praga, o monitoramento da suscetibilidade de populações de C. includens é estratégico para um eficiente programa de Manejo da Resistência de Insetos. Portanto, objetivou-se com este estudo avaliar os níveis de suscetibilidade de populações de C. includens no estado de Mato Grosso, Brasil, aos inseticidas lufenurom e espinosade. Sete populações foram coletadas em cultivos de soja ao longo do estado. Para os bioensaios, lagartas em terceiro ínstar foram expostas aos inseticidas utilizando o método de contaminação superficial de dieta. Embora os compostos apresentem modos de ação distintos, a população de Tangará da Serra obteve as maiores razões de resistência para lufenurom (11,62) e espinosade (7,84) em relação à população de laboratório (referência de suscetibilidade). Apesar dos níveis de resistência terem sido baixos, é necessário manter a manutenção do monitoramento dos níveis de suscetibilidade aos inseticidas avaliados, assim como ampliar a gama de moléculas monitoradas.(AU)

Canna indica-chitin-alginate composite beads for the treatment of textile dye effluent containing Rose Bengal dye

Aim: To study the adsorption of Rose Bengal dye used in textile industries by Canna indica-chitin-alginate beads. Methodology: C. indica-chitin-alginate composite beads were prepared using root tubers of Canna indica, chitin from shrimp shells and sodium alginate. Batch adsorption of Rose Bengal dye was carried out with optimized parameters like pH, contact time, adsorbent dosage and dye concentrations. Characterization studies like SEM, FTIR and TGA and reusability of composite beads were also studied. Results: The maximum adsorption of 97.9% was obtained at pH 6, 80 min contact time with the optimized ratio of 1:1:0.05 C. indica-chitin-alginate towards 100 mg l-1 dye concentration. The SEM analysis showed a porous surface morphology whereas FTIR results exhibited the functional groups of Rose Bengal dye and composite beads, proving successful adsorption. Thermogravimetric analysis revealed that the composite beads could withstand a maximum temperature of 300oC. Interpretation: It is inferred from the study that a biosorbent prepared from a commonly available plant and shells of shrimp, which is considered as a waste, can be effectively used in the adsorption of harmful textile dyes from the effluent in an eco-friendly and cost-effective way.

Regulatory mechanism underlying mycelium aggregation during filamentous fungi submerged fermentation / 生物工程学报

Filamentous fungi are one of the platforms for producing fermented products. The specific characteristic of their submerged fermentation is the aggregation of mycelia that is affected by environmental conditions, leading to significantly different rheology for fermentation broth. Such a rheological change not only affects the transfer of mass, heat and momentum, but also the biosynthesis of target products and the efficiency of their production. In this article, strategies for morphological regulation of filamentous fungi are reviewed, and the impact of calcium signal transduction and chitin biosynthesis on apical growth of hyphae and branching of mycelia for their aggregation are further commented.

Otimização e padronização de processos para obtenção de quitosana purificada para uso farmacêutico e alimentício / Optimization and standardization of processes to obtain purified chitosan for pharmaceutical and food use

Quitosana é um biopolímero encontrado principalmente na parede celular de crustáceos e é obtida pela desacetilação da quitina. Como biopolímero a quitosana é utilizada como excipiente para medicamentos e composição de alimentos. No entanto a quitosana devidamente purificada para uso farmacêutico ou alimentício tem custo financeiro elevado. Outro fator que contribui para o uso limitado é a falta de procedimento padronizado para desacetilação, o que resulta em materiais com diferentes graus de qualidade, dificultando suas aplicações e controle de qualidade de matéria prima e produto. Este trabalho tem como principal objetivo estabelecer procedimento reprodutível para a extração da quitina e da quitosana, por meio da aplicação dos conceitos de Quality by Design e planejamento de experimentos. A quitosana foi obtida pela desacetilação da quitina de crustáceos pelas etapas de desmineralização, desproteinização e despigmentação. O procedimento técnico para purificação da quitosana foi definido a partir de planejamento fatorial com ponto central para as etapas otimizadas, por meio da aplicação dos conceitos de Quality by Design e planejamento de experimentos. O projeto definiu um procedimento padronizado para purificação da quitosana que pode ser empregado em escala industrial, e financeiramente vantajoso para produção de medicamentos ou alimentos

Chitosan is a biopolymer found mainly in the cell wall of crustaceans and is obtained by the deacetylation of chitin. As biopolymer chitosan is used as excipient for medicaments and food composition. However, chitosan duly purified for pharmaceutical or food use has a high financial cost. Another factor that contributes to the limited use is the lack of standardized procedure for deacetylation, which results in materials with different grades of quality, hindering their applications and quality control of raw material and product. This work has as main objective to establish a reproducible procedure for the extraction of chitin and chitosan, through the application of the concepts of Quality by Design and planning of experiments. Chitosan was obtained by the deacetylation of chitin from crustaceans through the demineralization, deproteinization and depigmentation stages. The technical procedure for purification of chitosan was defined from a factorial planning with a central point for the optimized steps, through the application of the concepts of Quality by Design and planning of experiments. The project defined a standard procedure for the purification of chitosan that can be used on industrial scale and financially advantageous for the production of medicines or foods

Evaluación preliminar del efecto del quitosano y cáscara de naranja en la coagulación-floculación de aguas residuales / Preliminary evaluation of the effect of chitosan and orange peel in the coagulation-flocculation of wastewater

RESUMEN Las aguas de desecho dispuestas en una corriente superficial, lagos, ríos, mar, sin ningún tratamiento, ocasionan graves inconvenientes de contaminación, que afectan la flora y la fauna. Estas aguas residuales, antes de ser vertidas en las masas receptoras, deben recibir un tratamiento adecuado, capaz de modificar sus condiciones físicas, químicas y microbiológicas, para evitar que su disposición cause la alteración y la degradación de los ecosistemas asociados y problemas de salud pública. La investigación tuvo como objetivo evaluar el efecto de mezclas de quitosano y extracto acuoso de la cáscara de naranja, a diferentes concentraciones, en el proceso de coagulación-floculación, de aguas residuales, para lo cual, se realizó una prueba de jarras con agitación rápida y lenta, para evaluar turbidez (NTU), demanda química de oxígeno (DQO), demanda bioquímica de oxígeno (DBO), sólidos suspendidos totales (SST) y SS (sólidos sedimentables). Los resultados mostraron que todos los tratamientos presentaron diferencias significativas (p<0,05), con la muestra control y fueron eficientes en la reducción de turbidez, DBO, DQO, SST, SS. El tratamiento que combinó quitosano y extracto acuoso de cáscara de naranja (50-50%), a un pH de 5,5, disminuyó significativamente (p<0,05) la turbidez, en 79%, demostrando, de manera preliminar, que el extracto acuoso de la cáscara de naranja acidifica la mezcla e incrementa la formación de flóculos aglomerados en una fase liviana de las muestras, convirtiéndose en un agente eficiente, para ser usado en el tratamiento de aguas residuales.

ABSTRACT Waste water disposed in a superficial current, lakes, rivers, the sea, without any treatment, causes great inconvenient pollution that affects the flora and fauna of a region. This wastewater, before being poured into the receiving body of water, must receive the appropriate treatment, in order to modify its physical, chemical and microbiological conditions, to avoid that its disposal causes the alteration and degradation of the associated ecosystems and problem with public health. This research had as an objective to assess the effect of chitosan and aqueous extract of orange peel shells at different concentrations on the coagulation-flocculation process of wastewater. In order to do this, a jar test with fast and slow pull was carried out, assessing turbidity (NTU), chemical oxygen demand (COD), biochemical oxygen demand (BOD), total suspended solids (TSS) and SS (solid sediments). The results showed that all the treatments presented significant differences (p<0.05) to the control sample, and were efficient in the decrease of NTU, DQO, DBO, SST, and SS. The treatment that combined chitosan and aqueous extract of orange peel (50-50%) at a pH or 5.5, decreased significantly (p<0.05) the turbidity in a 79%, showing in a preliminary way that the aqueous extract of orange peel shells acidifies the mix and increases the formation of agglomerated floccules in a light phase of the samples, becoming an efficient agent to be used in the treatment of wastewater.

In vivo effect of diflubenzuron, administered via mineral salt supplementation, against Haematobia irritans and Rhipicephalus microplus parasitizing cattle / Efeito in vivo do diflubenzuron, administrado via sal mineral, contra Haematobia irritans e Rhipicephalus microplus parasitando bovinos

Abstract This study involved two field trials with the aim of evaluating the efficacy of diflubenzuron, via mineral supplementation, against Haematobia irritans parasitizing cattle. Concomitantly with the main trial, a stall test was conducted to ascertain the effects of a different formulation with the same active ingredient against Rhipicephalus microplus, along with the action of diflubenzuron on the reproductive parameters of R. microplusfemales that had naturally detached from cattle. Against H. irritans, it was observed that the efficacy indexes fordiflubenzuron were low (≤ 31.3% or 44.6%) or null (0.0%) throughout the study. The anti- R. microplus efficacy of diflubenzuron, at weekly intervals, ranged from 0.0 to 13.7% over the entire experimental period. Null efficacy (0.0%) was registered for diflubenzuron in relation to the reproductive parameters of R. microplusfemales that had naturally detached from cattle. The different diflubenzuron formulations, administered via mineral salt supplementation, did not show satisfactory efficacy indexes against H. irritans and R. microplus parasitizing cattle, within the experimental design of the present study. In addition, this agent did not present any deleterious effects on the reproductive parameters of R. microplus females.

Resumo O objetivo deste estudo foi avaliar a eficácia do diflubenzuron, administrado via suplementação mineral, contra Haematobia irritans parasitando bovinos, em dois testes à campo. Concomitantemente, foi realizado testes em estábulo para determinar os efeitos de uma formulação diferente, com o mesmo princípio ativo, contra Rhipicephalus microplus , bem como a ação do diflubenzuron nos parâmetros reprodutivos de fêmeas de R. microplus recolhidas após desprendimento natural do hospedeiro bovino. Contra H. irritans, foi observado que foram baixos (≤ 31,3% ou 44,6%) ou nulos (0,0%) os índices de eficácia do diflubenzuron. A eficácia anti-R. microplus do diflubenzuron, observada em intervalos semanais, variaram de 0,0% a 13,7% durante todo o período experimental. Com relação aos parâmetros reprodutivos das fêmeas de R. microplus recolhidas, foi observada eficácia nula (0,0%) para o diflubenzuron. Conclui-se que as diferentes formulações administradas via sal mineral no atual estudo, contra H. irritans e R. microplus parasitando bovinos, não apresentaram eficácia satisfatória. Este agente também não mostrou efeito deletério sobre os parâmetros reprodutivos de fêmeas de R. microplus.

Alternative splicing originates different domain structure organization of Lutzomyia longipalpis chitinases

BACKGROUND The insect chitinase gene family is composed by more than 10 paralogs, which can codify proteins with different domain structures. In Lutzomyia longipalpis, the main vector of visceral leishmaniasis in Brazil, a chitinase cDNA from adult female insects was previously characterized. The predicted protein contains one catalytic domain and one chitin-binding domain (CBD). The expression of this gene coincided with the end of blood digestion indicating a putative role in peritrophic matrix degradation. OBJECTIVES To determine the occurrence of alternative splicing in chitinases of L. longipalpis. METHODS We sequenced the LlChit1 gene from a genomic clone and the three spliced forms obtained by reverse transcription polymerase chain reaction (RT-PCR) using larvae cDNA. FINDINGS We showed that LlChit1 from L. longipalpis immature forms undergoes alternative splicing. The spliced form corresponding to the adult cDNA was named LlChit1A and the two larvae specific transcripts were named LlChit1B and LlChit1C. The B and C forms possess stop codons interrupting the translation of the CBD. The A form is present in adult females post blood meal, L4 larvae and pre-pupae, while the other two forms are present only in L4 larvae and disappear just before pupation. Two bands of the expected size were identified by Western blot only in L4 larvae. MAIN CONCLUSIONS We show for the first time alternative splicing generating chitinases with different domain structures increasing our understanding on the finely regulated digestion physiology and shedding light on a potential target for controlling L. longipalpis larval development.

Preparation and biocompatibility of nano polypyrrole/chitin composite membrane / 中国修复重建外科杂志

Objective: To prepare nano polypyrrole (PPy)/chitin composite membrane and observe their biocompatibility. Methods: The nano PPy was synthesized by microemulsion polymerization, blended with chitosan and then formed membranes. The membranes were then modified by acetylation to get the experimental membranes (nano PPy/chitin composite membranes, group A). The chitosan membranes (group B) and chitin ones (group C) modified by acetylation acted as control. Scanning electron microscopy and FT-IR spectra were used to identify the nano PPy and the membranes of each group. And the conductivity of membranes of each group was measured. Schwann cells were co-cultured in vitro with each group membranes to observe the biocompatibility by inverted microscope observing, living cell staining, cell counting, and immunofluorescence staining. The lysozyme solution was used to evaluate the degradation of the membranes in vitro. Results: The FT-IR spectra showed that the characteristic vibrational absorption peaks of C=C from nano PPy appeared at 1 543.4 cm -1 and 1 458.4 cm -1. Scanning electron microscopy observation revealed that the size of nano PPy particles was about 100-200 nm. The nano PPy particles were synthesized. It was successful to turn chitosan to chitin by the acetylation, which was investigated by FT-IR analysis of membranes in groups A and C. The characteristic peaks of the amide Ⅱ band around 1 562 cm -1 appeared after acetylated modification. Conductivity test showed that the conductivity of membranes in group A was about (1.259 2±0.005 7)×10 -3 S/cm, while the conductivity of the membranes in groups B and C was not detected. The nano PPy particles uniformly distributed on the surface of membranes in group A were observed by scanning electron microscope; the membranes in control groups were smooth. As a result, the nano PPy/chitin composite membranes with electrical conductivity were obtained. The cultured Schwann cells were found to survive with good function by fluorescein diacetate live cell staining, soluble protein-100 immunofluorescence staining, and inverted microscope observing. The cell counting showed that the proliferation of Schwann cells after 2 days and 4 days of group A was more than that of the two control groups, and the differences were significant ( P<0.05). It indicated that the nano PPy/chitin composite membranes had better ability of adhesion and proliferation than those of chitosan and chitin membranes. The degradation of membranes in vitro showed that the degradation rates of membranes in groups A and C were significantly higher than those in group B at all time points ( P<0.05). In a word, the degradation performance of the membranes modified by acetylation was better than that of chitosan membranes under the same condition. Conclusion: The nano PPy and chitosan can be blended and modified by acetylation successfully. Nano PPy/chitin composite membranes had electrical conductivity, degradability, and good biocompatibility in vitro.

Avaliação biomecânica e dimensional do fio de sutura à base de quitosana / Biomechanics and dimensional evaluation of the suture based on chitosan

A resistência à tração e o diâmetro são características de grande importância na avaliação da qualidade de fios de sutura, estando relacionados à capacidade destes de suportar o estresse promovido pelas forças atuantes em determinados tecidos. Desta forma, objetivou-se com este estudo avaliar as propriedades mecânica e dimensional de fios de sutura à base de quitosana, comparando-as com as preconizadas pela norma NBR 13904/2003. Tais propriedades foram avaliadas usando-se uma máquina de ensaio universal e um micrômetro digital. Os parâmetros mecânico e dimensional analisados foram a resistência quanto à tração, a deformação, bem como o diâmetro, respectivamente. O valor médio do diâmetro dos fios de quitosana apresentou variação e observou-se resistência à tração ligeiramente abaixo da norma preconizada, com rápida deformação. O fio de quitosana, na forma em que foi produzido, apresentou variabilidade dimensional e baixa resistência à tração, havendo a necessidade de melhorias no método de fabricação dele.(AU)

Tensile strength and diameter are very important characteristics in assessing the quality of suture, being related to their ability to withstand the stress caused by forces acting in certain tissues. Thus, the aim of this study was to evaluate the mechanical and dimensional properties of chitosan-based suture, comparing them with those recommended by the NBR 13904/2003. These properties were evaluated by using a universal testing machine and a digital micrometer. The mechanical and dimensional parameters analyzed were resistance to traction, deformation and diameter, respectively. The average diameter of the chitosan showed variation and yarn tensile strength was observed slightly below the recommended standard, with rapid deformation. The chitosan yarn in the form in which it was produced, presented dimensional variability and low tensile strength, there is a need for improvements in the method of manufacturing the same.(AU)

Sequencing and de novo assembly of the Asian gypsy moth transcriptome using the Illumina platform

Abstract The Asian gypsy moth (Lymantria dispar) is a serious pest of forest and shade trees in many Asian and some European countries. However, there have been few studies of L. dispar genetic information and comprehensive genetic analyses of this species are needed in order to understand its genetic and metabolic sensitivities, such as the molting mechanism during larval development. In this study, high-throughput sequencing technology was used to sequence the transcriptome of the Asian subspecies of the gyspy moth, after which a comprehensive analysis of chitin metabolism was undertaken. We generated 37,750,380 high-quality reads and assembled them into contigs. A total of 37,098 unigenes were identified, of which 15,901 were annotated in the NCBI non-redundant protein database and 9,613 were annotated in the Swiss-Prot database. We mapped 4,329 unigenes onto 317 pathways using the Kyoto Encyclopedia of Genes and Genomes Pathway database. Chitin metabolism unigenes were found in the transcriptome and the data indicated that a variety of enzymes was involved in chitin catabolic and biosynthetic pathways.

Studies on site-directed mutagenesis of BmK AngM1 from scorpion venom and its anti-inflammatory activity / 药学学报

Scorpion toxin BmK AngM1 has been reported to have a strong analgesic effect. However, its anti-inflammatory activity was unknown. In this study, the recombinant BmK AngM1 (rBmK AngM1) was expressed in Escherichia coli BL21 trxB (DE3). The purified rBmK AngM1 was obtained efficiently through the IMPACTTM-TWIN system. The anti-inflammatory activity of the recombinant protein was investigated. In order to improve the anti-inflammatory activity of rBmK AngM1, the potential active sites (Y5, Y42, R58) were substituted with different amino acids. The results showed that rBmK AngM1 and its mutants all have significant anti-inflammatory activity. The activities were significantly increased in the single mutant R58N and mutants Y5F/R58N, Y42F/R58N over the wild type protein. The data suggest that position 58 in BmK AngM1 plays a functional role in the anti-inflammatory activity. This study lays a foundation for the protein engineering design of BmK AngM1 to improve its pharmacological activity.

Study on theimmediate separation feasibility of PLT preparation by adding to carboxylation chitosan / 中国输血杂志

Objective To investigate the use of chitin derivatives-carboxylation chitosan immediate separation feasibility of PLT preparation,and to look for a new direction in separation feasibility of blood components.Methods 40 samples of blood donors were divided into the experimental group,natural sedimentation control group and centrifugal control group randomLy in Dalian.2 mL of whole blood were mixed with different concentrations of carboxylation chitosan which were diluted by blood preservation solution Ⅱ by according to the ratio of 1 ∶4.plasma precipitation amount were surveyed after 4 hours,with numbers of red blood cells,white blood cell and platelet,PLT aggregation and the changes of red blood cell morphology were observed.Finally,suitable amount of MAP were added into the optimal chitosan in preservation,and hemolysis of red blood cells were tested in 35 days.Results Suitable amount of chitin experimental group blood sedimentation rate were significantly faster than static device control group,and plasma remaining trace red blood cells,PLT-rich,and 35 days no obvious hemolysis.Conclusion carboxylation chitosan could be used in PLT preparation.