Qualidade físico-química e atividades biológicas de caseinofosfopeptídeos obtidos por hidrólise tríptica de caseinato de sódio sob diferentes condições

<p>Muitos métodos têm sido empregados na produção de peptídeos bioativos para a promoção da saúde. O objetivo deste estudo foi produzir caseinofosfopeptídeos por hidrólise tríptica do caseinato de sódio usando diferentes temperaturas (37 e 50 °C) e tempos de reação (2 e 4 h), caracterizá-los e analisar sua influência nas atividades citotóxica, antimicrobiana e antioxidante. Caseinofosfopeptídeos foram caracterizados através da composição centesimal, eletroforese em gel de poliacrilamida, Espectrometria de Massas e Cromatografia Líquida de Alta Eficiência. Toxicidade para leucócitos humanos, atividade antimicrobiana utilizando o teste de microdiluição em caldo e determinação da capacidade antioxidante pelo método de espécies reativas ao ácido tiobarbitúrico foram os ensaios biológicos realizados. Os resultados mostraram que as quatro frações peptídicas obtidas apresentaram-se com baixo peso molecular e elevados teores proteico e mineral; quanto ao perfil aminoacídico, apresentaram elevadas e diferenciadas quantidades de ácido glutâmico e serina, que pouco variaram de acordo com o processo de obtenção; não se mostraram tóxicos para leucócitos humanos; demonstraram atividade antimicrobiana para Escherichia coli e Salmonella Enteritidis e elevada capacidade antioxidante. Os resultados físico-químicos das frações de caseinofosfopeptídeos demonstraram elevada composição nutricional em termos de proteína e, principalmente, cálcio. O conjunto de dados indicou que alterações no tempo e na temperatura de reação para a obtenção dos hidrolisados não interferem nas suas qualidades biológicas, mostrando serem seguros para a promoção da saúde e para a aplicação em situações especiais, que envolvem pacientes desnutridos, imunossuprimidos, com comprometimento ósseo ou gastrintestinal decorrentes de inflamações e infecções.</p><p>PALAVRAS-CHAVE: Caseinofosfopeptídeos. Caseinato de sódio. Citotoxicidade. Atividade antimicrobiana. Atividade antioxidante.</p><p> </p><p>ABSTRACT</p><p><br />Physico-chemical quality and biological activities of Casein phosphopeptides obtained by sodium caseinate tryptic hydrolysis under different conditions</p><p><br />Several methods have been employed for the production of bioactive peptides for health promotion. The aim of this study was to produce and characterize Casein phosphopeptides obtained by sodium caseinate tryptic hydrolysis under different temperatures (37 and 50 °C) and reaction times (2 and 4 h), and evaluate their biological capabilities. They have been characterized by assessing their centesimal composition, by polyacrylamide gel electrophoresis, Mass Spectrometry, and High-Performance Liquid Chromatography. The biological activities tested included toxicity for human leukocytes, antimicrobial assay using the microdilution test, and determination of the antioxidant capacity by the thiobarbituric acid reactive species method. The results showed that the four fractions obtained were of low molecular weight with high protein and mineral contents; their amino acid profile showed high and differentiated amounts of glutamic acid and serine independent of the methodological procedures. The results also showed no toxicity for human peripheral leukocytes, demonstrated antimicrobial activity against Escherichia coli and Salmonella Enteritidis as well as high antioxidant capacity. The results of the physico- chemical Casein phosphopeptides’ fractions showed high nutritional composition in terms of protein and, particularly, calcium. The biological assays indicated that time and temperature changes in the process for obtaining casein hydrolysates have not interfered with their biological qualities. In addition, they have proven safe in promoting health in special conditions involving malnourished and/or, immunocompromised patients or those with bone and/or gastrointestinal impairment due to inflammations and infections.</p><p><br />Keywords: Casein phosphopeptides. Sodium caseinate. Cytotoxicity. Antimicrobial activity. Antioxidant activity.</p

A prospective study on Aeromonas in outpatients with diarrhea in the central region of Rio Grande do Sul State

Aeromonas spp. were identified in five (2,7%) of 182 diarrheal stool cultures, A. caviae was predominant, resistant mainly to ampicillin and cephalotin. This is the first study showing the presence of Aeromonas spp. in diarrheal stools of outpatients in the central region of Rio Grande do Sul State, Brazil

Utilization of carbon sources by clinical isolates of Aeromonas

Bacteria in the genus Aeromonas are primarily aquatic organisms; however, some species can cause diseases in humans, ranging from wound infections to septicemia, of which diarrhea is the most common condition. The ability to use a variety of carbon substrates is advantageous for pathogenic bacteria. Therefore, we used Biolog GN2 microplates to analyze the ability of 103 clinical, predominantly diarrheal, isolates of Aeromonas to use various carbon sources and verified whether among the substrates metabolized by these strains there were some endogenous to the human intestine. Results indicate that Aeromonas present great diversity in the utilization of carbon sources, and that they preferentially use carbohydrates and amino acids as carbon sources. Among the carbon sources metabolized by Aeromonas in vitro, some were found to be components of intestinal mucin including aspartic acid, glutamic acid, L-serine, galactose, N-acetyl-glucosamine, and glucose, which were used by all strains tested. Additionally, mannose, D-serine, proline, threonine, and N-acetyl-galactosamine were used by several strains. The potential to metabolize substrates endogenous to the intestine may contribute to Aeromonasâ capacity to grow in and colonize the intestine. We speculate that this may help explain the ability of Aeromonas to cause diarrhea.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

MOLECULAR IDENTIFICATION OF AEROMONAS SPP ISOLATED FROM PATIENTS WITH DIARRHEA AT SANTA MARIA-RS, BRAZIL

Objective: The aim of the study was to determine the frequency of Aeromonas spp. in stool samples of outpatients with gastroenteritis attended by clinical laboratories at Santa Maria-RS, Brazil.Methods: In order to evaluate this frequency, 767 clinical stool samples were processed by conventional methods as preconized, and suspected Aeromonas strains were submitted to molecular characterization by 16SrRNA PCR-RFLP method.Results: Aeromonas spp. were isolated from 14 (1.8%) of stool cultures and identified as A. caviae (04), A. hydrophila (03), and A. veronii biovar sobria (01) by molecular method. Six strains presented atypical PCR-RFLP patterns, and therefore were identified as Aeromonas spp.Conclusion: Aeromonas is part of the bacteria associated with diarrhea in Santa Maria-RS, and results indicates that at least 3 Aeromonas species are involved with the disease.Â

Morphological and molecular identification of filamentous fungi isolated from cosmetic powders

Seven fungi were isolated from 50 samples of cosmetic powders. Morphological analyses and ribosomal DNA Internal Transcribed Spacers sequencing were performed which allowed the discrimination of the isolated fungi as Aspergillus fumigatus, Penicillium sp., and Cladosporium sp. which could have, among their species, potentially pathogenic microorganisms