Purificação de toxinas produzidas por Clostridium perfringens: uma revisão

Clostridium perfringensé uma bactéria anaeróbia Gram-positiva, amplamente distribuída no meio ambiente e comumente encontrada no intestino de animais, incluindo o homem. As espécies de C. perfringensestão classificadas em cinco tipos toxigênicos (A, B, C, D, E) em função da produção de quatro toxinas (±, ², µ, ¹). Entretanto, as toxinas teta, delta, lambda e enterotoxina são também sintetizadas por outras espécies dessa bactéria. Muitas metodologias para purificação das toxinas produzidas por C. perfringens têm sido propostas e, portanto, nesta revisão foram apresentados e discutidos os métodos e resultados de purificação dessas toxinas relatados nas últimas quatro décadas.Clostridium perfringens, a Gram-positive anaerobic bacterium, is widespread in the environment and commonly found in the intestines of animals, including humans. C. perfringens strains are classified into five toxinotypes (A, B, C, D and E) based on the production of four major toxins (±, ², µ, ¹). However the toxins (theta, delta, lambda and enterotoxin) are also synthesized by C. perfringens strain. Many attempts to purify the toxins produced by C. perfringens have been proposed. In this review we discuss the purification methods used to isolate toxins from C. perfringens reported in last four decades

The use of poultry feather to produce keratinase by Aspergillus carbonarius

O objetivo deste trabalho foi estudar a produção de queratinase por Aspergillus carbonarius URM 1546, tendo-se como substrato penas de galinha, por meio de planejamento fatorial completo 23. Todos os parâmetros estudados e as interações de segunda ordem foram estatisticamente significativos. A maior atividade queratinolítica (48,9 U mL-1) foi obtida com 120 rpm, 0,5% (p/v) de penas de galinha e sete dias de cultivo.The objective of this work was to evaluate the keratinase production by Aspergillus carbonarius URM 1546, using as substrate poultry feather in a full experimental design 23. The studied parameters and the second-order interactions were statistically significant. The maximum keratinase activity (48.9 U mL-1) was obtained using 120 rpm, with 0.5% (w/v) poultry feather and seven culture days

Saccharomyces cerevisiae from Brazilian kefir-fermented milk: An in vitro evaluation of probiotic properties

The therapeutic use of probiotics for supporting the antibiotic action against gastrointestinal disorders is a current trend and emerging applications have gained popularity because of their support for various microbiological activities in digestive processes. Microorganisms isolated from kefir with great probiotic properties, in addition to high resistance to harsh environmental conditions, have been widely researched. Administration of probiotic yeasts offers a number of advantages, when compared to bacteria, because of particular characteristics as their larger cell size. In the present study, 28 strains of Saccharomyces cerevisiae were isolated, after in vitro digestion of kefir-fermented milk, and identified by molecular based approaches. A screening was performed to determine important quality requirements for probiotics including: antagonistic and antioxidant activities, -galactosidase synthesis, autoaggregation, surface hydrophobicity and adhesion to epithelial cells. The results showed strains: with antagonistic activity against microbial pathogens such as Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis; able to produce -galactosidase; with antioxidant activity levels higher than 90%; with hydrophobicity activity and autoaggregation ability (evaluated by adhesion test, where all the strains presented adhesion to mice ileal epithelial cells). These findings are relevant and the strains are recommended for further in vivo studies as well as for potential therapeutic applications.The authors thank the financial support of CAPES (National Council for the Improvement of Higher Education); the identification of yeast strains by Micoteca URM (Department of Mycology -UFPE); professor Daniela Marques and PhD student Rebeca Melo for providing the mice intestine and the laboratory of Histology (DMFA-UFRPE) for the histological pictures.info:eu-repo/semantics/publishedVersio

Process development for the production of prebiotic fructo-oligosaccharides by Penicillium citreonigrum

A new isolated P. citreonigrum URM 4459 was selected to produce fructooligosaccharides (FOS) in an efficient, economical and fast one-step fermentation. Optimal culture conditions were stablished by experimental design. Experiments run in bioreactor resulted in a high yield, content, productivity and purity of FOS (0.65 ± 0.06 gFOS.ginitial sucrose-1, 126.3 ± 0.1 g/L, 2.28 ± 0.08 g/L.h and 61 ± 0 %). The FOS mixture was purified up to 92 % (w/w) with an activated charcoal column. FOS produced were able to promote lactobacilli and bifidobacteria growth. Higher bacteria cell density was obtained for microbial-FOS mixtures than commercial Raftilose® P95. Some strains grew even faster in the FOS mixture produced than in all other carbon sources. FOS were resistant to the simulated gastrointestinal conditions. A high amount of a reducing trisaccharide was identified in the FOS produced mixture, possibly neokestose, which may explain the great prebiotic potential of the FOS.CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico, Brasília, Brazil) the approved project in network Renorbio – 140366/2014-8, Facepe (Fundação de Amparo à Ciência e Tecnologia do Estado de Pernambuco, Recife, Brasil, AMD-0273-2.00/14) and Capes (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Brasília, Brazil) for the 88881.119817/2016-01 funding. This study was also supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2019 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 – Programa Operacional Regional do Norte also, Project ColOsH 02/SAICT/2017 (POCI-01-0145-FEDER-030071). The authors acknowledge also University of Aveiro and FCT/MCT for the financial support for the QOPNA research Unit (FCT UID/QUI/00062/2019) through national founds and, where applicable, co-financed by the FEDER, within the PT2020 Partnership Agreement. Elisabete Coelho and Soraia P. Silva acknowledge FCT for the postdoctoral grant SFRH/BPD/70589/2010 and PhD grant SFRH/BD/136471/2018, respectively. This work was also funded by national funds (OE), through FCT, in the scope of the framework contract foreseen in the numbers 4, 5 and 6 of the article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19info:eu-repo/semantics/publishedVersio

Utilização de penas de galinha para produção de queratinase por Aspergillus carbonarius The use of poultry feather to produce keratinase by Aspergillus carbonarius

O objetivo deste trabalho foi estudar a produção de queratinase por Aspergillus carbonarius URM 1546, tendo-se como substrato penas de galinha, por meio de planejamento fatorial completo 2³. Todos os parâmetros estudados e as interações de segunda ordem foram estatisticamente significativos. A maior atividade queratinolítica (48,9 U mL-1) foi obtida com 120 rpm, 0,5% (p/v) de penas de galinha e sete dias de cultivo.The objective of this work was to evaluate the keratinase production by Aspergillus carbonarius URM 1546, using as substrate poultry feather in a full experimental design 2³. The studied parameters and the second-order interactions were statistically significant. The maximum keratinase activity (48.9 U mL-1) was obtained using 120 rpm, with 0.5% (w/v) poultry feather and seven culture days

Queijo de coalho artesanal: fonte alternativa de peptídeos antimicrobianos

Resumo O objetivo da pesquisa foi extrair, obter o perfil peptídico e avaliar a atividade antimicrobiana do extrato peptídico bruto de duas amostras de queijo de Coalho artesanal produzidos no município de Venturosa, localizado no Agreste de Pernambuco – Brasil. Nas eletroforeses realizadas, foram evidenciadas de 12 a 15 bandas. Na análise por espectrometria de massa, foram identificados 24 fragmentos peptídeos. O extrato peptídico bruto apresentou atividade antimicrobiana diante dos microrganismos Enterococcus faecalis ATCC 6057, Bacillus subtilis ATCC 6633, Escherichia coli ATCC 25922 e Pseudomonas aeruginosa ATCC 27853 na concentração de 225 mg/mL. Os presentes resultados sugerem que em aproximadamente 5 g do queijo são encontrados peptídeos capazes de inibir o crescimento dos microrganismos patogênicos testados. Sendo assim, pode-se indicar o caráter funcional do queijo de Coalho

Queijos artesanais: fonte de bactérias ácido láticas selvagens para formulação de fermentos tradicionais

O objetivo desse trabalho foi avaliar os aspectos tecnológicos de bactérias ácido láticas isoladas a partir de queijo de coalho artesanal para o desenvolvimento de um fermento. Sendo assim, foi realizado isolamento, identificação clássica, capacidade acidificante (pH e produção de ácido lático), proteolítica e antagonista de bactérias ácido-láticas. Os resultados obtidos mostraram que a população bacteriana encontrada foi composta em sua maioria por cocos, com presença dos gêneros Lactococcus, Leuconostoc, Enterococcus, e Streptococcus, além dos Lactobacillus, numa proporção aproximada de 1:3,5:13:2:1,5. Foram observadas bactérias classificadas como rápidas e lentas acidificantes, sendo esse equilíbrio importante para a formulação de um novo fermento. Em relação à capacidade proteolítica, no teste qualitativo de produção de proteases, poucas apresentaram halos, entretanto, todas produziram enzimas proteolíticas extracelulares, com pico de produção entre 24 e 48h de cultivo, chegando até 11,71 U/mL de atividade total. Um total de 42,2% das bactérias avaliadas apresentou atividade antagonista frente a Escherichia coli, Klebsiella pneumoniae e Staphylococcus aureus. Pode-se, então, concluir que as bactérias ácido láticas isoladas a partir dos queijos de coalho artesanais possuem características importantes para a indústria de produtos lácteos na utilização como culturas starters

Mannose-binding lectin 2 (MBL2) gene polymorphisms do not influence frequency of infections in chronic lymphocytic leukemia patients

Background: Infectious complications represent the main cause of morbidity and mortality in chronic lymphocytic leukemia. It has been reported that polymorphisms of the mannosebinding lectin 2 (MBL2) genes are correlated with MBL protein serum levels and, consequently, are associated with the development of infectious diseases. Objective: The purpose of this study was to investigate the possible association between MBL2 gene polymorphisms and risk of infection in chronic lymphocytic leukemia patients. Methods: Peripheral blood samples from 116 chronic lymphocytic leukemia patients were collected; after genomic DNA extraction, real time polymerase chain reaction was used to determine the polymorphisms of the promoter region and exon 1 of the MBL2 gene. Results: A high frequency of Binet stage A (p-value = 0.005) and absence of splenomegaly (p-value = 0.002) were observed in patients with no infection; however, variant alleles/ genotypes and haplotypes of this gene had no impact on the risk of infection. Conclusion: To the authors' knowledge, this is the first study describing the association between MBL2 polymorphisms and infectious disease in chronic lymphocytic leukemia. Although it was not possible to demonstrate any influence of MBL2 polymorphisms as a genetic modulator of infection in chronic lymphocytic leukemia, the authors believe that the present data are clinically relevant and provide the basis for future studies