This paper presents the quantification, antioxidant and antimicrobial activity of capsaicin, dihydrocapsaicin and the flavonoid chrysoeriol isolated from different extracts (hexane and acetonitrile extracts from whole fruit, peel and seed) of Capsicum frutescens (pimenta malagueta). The acetonitrile extract of the seeds, peel and whole fruits contained capsaicin as a major component, followed in abundance by dihydrocapsaicin and chrysoeriol. The antimicrobial activity of the isolated compounds against seven microorganisms showed chrysoeriol was the most active compound. In the antioxidant test, the acetonitrile extract from the whole fruit showed the highest activity. The antioxidant activity of pimenta malagueta may be correlated with its phenolic content, principally with the most active compound, capsaicin.

BackgroundThe cotton boll weevil (Anthonomus grandis) is a serious insect-pest in the Americas, particularly in Brazil. The use of chemical or biological insect control is not effective against the cotton boll weevil because of its endophytic life style. Therefore, the use of biotechnological tools to produce insect-resistant transgenic plants represents an important strategy to reduce the damage to cotton plants caused by the boll weevil. The present study focuses on the identification of novel molecules that show improved toxicity against the cotton boll weevil. In vitro directed molecular evolution through DNA shuffling and phage display screening was applied to enhance the insecticidal activity of variants of the Cry8Ka1 protein of Bacillus thuringiensis.ResultsBioassays carried out with A. grandis larvae revealed that the LC50 of the screened mutant Cry8Ka5 toxin was 3.15-fold higher than the wild-type Cry8Ka1 toxin. Homology modelling of Cry8Ka1 and the Cry8Ka5 mutant suggested that both proteins retained the typical three-domain Cry family structure. The mutated residues were located mostly in loops and appeared unlikely to interfere with molecular stability.ConclusionsThe improved toxicity of the Cry8Ka5 mutant obtained in this study will allow the generation of a transgenic cotton event with improved potential to control A. grandis.

Bacillus thuringiensis (Bt) is a gram-positive spore-forming soil bacterium that is distributed worldwide. Originally recognized as a pathogen of the silkworm, several strains were found on epizootic events in insect pests. In the 1960s, Bt began to be successfully used to control insect pests in agriculture, particularly because of its specificity, which reflects directly on their lack of cytotoxicity to human health, non-target organisms and the environment. Since the introduction of transgenic plants expressing Bt genes in the mid-1980s, numerous methodologies have been used to search for and improve toxins derived from native Bt strains. These improvements directly influence the increase in productivity and the decreased use of chemical insecticides on Bt-crops. Recently, DNA shuffling and in silico evaluations are emerging as promising tools for the development and exploration of mutant Bt toxins with enhanced activity against target insect pests. In this report, we describe natural and in vitro evolution of Cry toxins, as well as their relevance in the mechanism of action for insect control. Moreover, the use of DNA shuffling to improve two Bt toxins will be discussed together with in silico analyses of the generated mutations to evaluate their potential effect on protein structure and cytotoxicity.

*Autor correspondente RESUMO: Estudos sobre morfologia floral e biologia reprodutiva de uma cultura contribuem para o desenvolvimento de técnicas de castração e polinização. Com este propósito, estudaram-se a estrutura e a biologia floral em cinco genótipos de aceroleira (Malpighia emarginata), em Jaboticabal, SP; no período de dezembro/97 a janeiro/99. Foi avaliada a morfologia floral, por caracterização e quantificação, e a biologia reprodutiva, desde o aparecimento dos primórdios do botão floral até a abertura. As flores da aceroleira são monóclinas, com cálice composto por seis a sete sépalas, corola de cinco pétalas, nove a dez glândulas presentes na base, androceu com dez estames e gineceu com três a quatro pistilos e distribuem-se em cimeiras axilares com 3 a 13 flores nos ramos do ano anterior e do mesmo ano. Verificaram-se de 6 a 7 floradas por ano, principalmente de janeiro a maio e de agosto a dezembro, registrando-se que desde o aparecimento do botão floral à antese decorrem 6,9 a 7 dias, com abertura floral entre 5h00 e 8h00 e das 14h00 às 16h00, com floração de 22,1 a 29,4 dias, decorrendo do florescimento à maturação do fruto 22 dias e duração da colheita de 19,7 a 28,8 dias. Palavras chave: Malpighia emarginata, floração, morfologia FLOWER MORPHOLOGY AND REPRODUCTIVE BIOLOGY OF WEST INDIAN CHERRY GENOTYPESABSTRACT: Flower morphology and reproductive biology knowledge of fruit crops may contribute to the development of castration and pollination tecniques. With this objective, flower structure and the biology of West Indian cherry genotypes were studied at Jaboticabal, SP, Brazil. Flower morphology was evaluated by characterization, quantification and reproductive biology, from flower bud beginning until opening. West Indian Cherry flower is hermaphrodite with a calix of six or seven sepals, corolla of five petals, nine or ten glands in the lower region, ten stamen androecium and gyneceum with three or four pistils. The flowers are distributed in bunches of 3 to 13 units each, on the same year or on the latest year branches. Plants flower 6 to 7 times per year, mainly from January to May and August to December periods, with about 7 days elapsed from flower bud appearance to anthesis, wich occurs from 5h00 to 8h00 AM and from 2h00 to 4h00 PM. The flowering period endures from 22.1 to 29.4 days. The fruit ripeness occurs 22 days after flowering and the crop lasts 19.7 to 28.8 days.

RESUMO -As medidas de variabilidade fenotípica, correlações, efeitos diretos e indiretos na aceroleira (Malpighia emarginata DC.) da região de Itápolis, SP, objetivaram direcionar o processo seletivo de genótipos. Os parâmetros comprimento e largura média de folhas, altura de planta, diâmetro de copa, peso médio de fruto, peso médio de polpa/fruto, peso médio de 20 frutos e peso médio de polpa por 20 frutos mostraram diferenças quanto a genótipos e épocas. Em acidez, tamanho e largura média de fruto, as diferenças são exclusivas em relação a épocas, sugerindo ações de condições climáticas. A altura é um bom parâmetro tipificador na diferenciação e seleção de genótipos. As condições meteorológicas podem influenciar marcadamente em caracteres tecnológicos (acidez) e em medidas dos frutos. Destacaram-se as associações positivas entre comprimento de folhas com tamanho e peso de frutos e as correlações negativas destes com vitamina C; seguida de correlações positivas e significativas de tamanho com largura de frutos. Dos efeitos diretos sobre vitamina C, relacionam-se os efeitos de Brix e diâmetro de copa como positivos. Contudo, nas condições estudadas, as medidas das folhas estão associadas positivamente com tamanho e peso dos frutos e negativamente com vitamina C. Além disso, observa-se que as medidas dos frutos associam-se positivamente com os caracteres de peso e rendimento, que estão negativamente associados com vitamina C. A seleção sobre Brix pode direcionar ganhos em polpa e em vitamina C.Termos para indexação: Malpighia emarginata, métodos de melhoramento, seleção, critérios de seleção, ganho genético, condições meteorológicas, melhoramento de plantas. PHENOTYPIC VARIABILITY IN WEST INDIAN CHERRY GENOTYPESABSTRACT -The measures in the phenotypic variability, correlation, direct and indirect effects in the West Indian cherry (Malpighia emarginata DC.), from Itápolis, São Paulo State, Brazil, aimed to subsidize the management of the selective process in the genotypes. The parameters length and width of leaves, height of plant, diameter of canopy, weight medium of fruit, weight of pulp/fruit, weight medium of 20 fruits and weight medium of pulp of 20 fruits, showed differences for genotypes and date of evaluation. The differences of acidity, size and width medium of fruit are exclusive for dates, suggesting actions of climatic conditions. The height is a good parameter leading to the differentiation for selection of genotypes. The meteorological conditions can influence remarkably the acidity and dimensions of the fruit. Positive associations among leaf length and the parameters that define size and weight of fruits and negative correlation of these parameters with vitamin C were observed; so as positive correlation of size and width of fruits. Brix and canopy diameter were positively correlated with vitamin C. Measures of the leaves are associated positively with size and weight of the fruits and negatively with vitamin C in the studied conditions. The measures of the fruits are directly associated with the c...

Of the many reported applications for xylanase, its use as a food supplement has played an important role for monogastric animals, because it can improve the utilisation of nutrients. The aim of this work was to produce xylanase by extractive fermentation in an aqueous two-phase system using Aspergillus tamarii URM 4634, increasing the scale of production in a bioreactor, partially characterising the xylanase and evaluating its influence on monogastric digestion in vitro. Through extractive fermentation in a bioreactor, xylanase was obtained with an activity of 331.4 U mL(-1) and 72% yield. The xylanase was stable under variable pH and temperature conditions, and it was optimally active at pH 3.6 and 90 °C. Xylanase activity potentiated the simulation of complete monogastric digestion by 6%, and only Mg2+ inhibited its activity. This process provides a system for efficient xylanase production by A. tamarii URM 4634 that has great potential for industrial use.

No abstract

Acremonium sp. L1-4B isolated from lichen in Antarctica was used to produce extracellular proteases through submerged fermentation using cactus pear extract (Opuntia ficus-indica Mill.). A 2 3 factorial design was applied to optimize the protease production using three independent variables, namely temperature, pH and concentration of yeast extract, was also used a Central Composite Design (CCD) under Response Surface Methodology (RSM). All variables and interactions analyzed in the factorial design were significant or marginally significant, a Central Composite Design was developed, and the Response Surface Methodology towards the highest point it was established. The experimental model was validated under 14°C, pH 7.54, and 0.55% yeast extract, showing a protease activity of 447.65 7 2.6 U/mL by a prediction model of 445.48 U/mL. The enzyme showed a molecular weight of 59 kDa; it was inhibited in the presence of PMSF (serine protease); it presented optimal conditions at pH 8.0 and 50°C; it remained stable at pH in the 3.0-9.0 range and between 10 and 40°C; it showed a tolerance to 3000 mM NaCl as well as to surfactants, hydrogen peroxide and urea at 5%. This paper presents a proposal for an economically attractive production methodology using cactus pear as a primary source of carbon. In addition, the protease secreted by Acremonium sp. L1-4B presented a combination of biochemical characteristics that grants a promising variability of biotechnological applications.