Screening of fungal metabolites in Brazil nuts using LC/MS/MS

The aim of this study was to evaluate quantitatively the occurrence of fungal metabolites in Brazil nuts. Nuts were collected from Agroforest production areas in Amazon basin region. A total of 235 mycotoxins were investigated/screened by a multi-mycotoxin method based on HPLC-MS/MS. The recovery was between 56 and 136%. Fifteen mycotoxins were detected and quantified, in at least one sample; namely, aflatoxins B1, B2, G1, and M1, kojic acid, sterigmatocystin, methyl-sterigmatocystin, citrinin, cyclosporin A, cyclosporin C, cyclosporin D, cyclosporin H, rugulosin, altenariol-methylether and emodin. Aflatoxins were detected in just 1 sample (20%), but above its legal limit in Brazil and EU. Ochratoxin A and Fusarium toxins were not detected. Alternariol-methylether (from 0.75 to 3.2 g.kg-1) was detected in all five samples. This is the first study dealing with the detection of kojic acid, citrinin, cyclosporin A, cyclosporin C, cyclosporin D, cyclosporin H, rugulosin, altenariol-methylether and emodin in Brazil nuts

Cloning, purification, and biochemical characterization of an esterase from Aspergillus nidulans

A large accumulation of agro-industrial waste from different segments is generated daily and is often not properly managed. There are now other fronts in research to give a destination to these residues; these studies are generally aimed at obtaining new and better enzymes and the formulation of enzymatic cocktails that contain (for example, cellulases and hemicellulases) responsible for the degradation of lignocellulosic material. The plant cell wall is mainly composed of cellulose, hemicellulose, and lignin, forming a complex structure. Xylan is one of the main constituents of hemicellulose. To degrade this structure, enzymatic hydrolysis must occur synergistically with xylanolytic enzymes, such as endo-beta-1,4-xylanases, -xylosidases, and acetyl xylan esterase (AXE). In the current work, we reported the purification and biochemical characterization of an acetyl xylan esterase (AxeCE3) from Aspergillus nidulans. The axeCE3 gene was cloned into the pEXPYR vector and transformed into A. nidulans A773 for protein expression. The enzyme AxeCE3 was purified and characterized for its biochemical properties. AxeCE3 showed activity over a wide range of pH (3.0-9.0) and temperature (30-70 °C), with maximum activity at 55 °C, pH 7.0. Regarding the stability at temperature, AxeCE3 showed values above 90% of residual activity after 24 h of incubation at 45 and 50 °C. In relation to stability at pH, AxeCE3 maintained more than 90% of its residual activity after being incubated at 25 °C for 24 h between the pH range 3.0 to 9.0. It was also verified the effect of possible inhibitors (ethylenediamine tetraacetic acid (EDTA), Furfural, and 5- Hydroxymethylfurfural (5-HMF)) on the enzyme activity. AxeCE3 maintained 88% of relative activity at 5 mM EDTA, 43% and 82% at 50 mM furfural and 5-HMF, respectively. The results showed that AxeCE3 has interesting properties to use in the development in the formulation of enzymatic cocktails for the hydrolysis of lignocellulosic residues.The work was supported by the following: FAPESP (São Paulo Research Foundation, grants: 2014/50884 and 2018/07522-6) and National Institute of Science and Technology of Bioethanol, INCT, CNPq (grant: 465319/2014-9) and process 301963/2017-7. Research scholarships were granted to RCA and DA by FAPESP (Grant No: 2020/00081-4 and No: 2020/15510-8), to GSA by CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Finance Code 001).info:eu-repo/semantics/publishedVersio

COMPARAÇÃO ENTRE OS TRATAMENTOS COM TANASE E COM GELATINA PARA CLARIFICAÇÃO DO SUCO DE CAJU ( Anacardium occidentale L.)

Comparou-se o tratamento da polpa do caju com tanase e com gelatina, visando à redução da turbidez e do teor de taninos. Os resultados indicaram que a redução das concentrações de taninos totais, hidrolisáveis, proantocianidinas e turbidez ficaram em 39%, 50%, 32% e 94% para sucos tratados com gelatina e 46%, 88%, 2% e 88% para a polpa tratada com tanase, respectivamente. Deste modo, o tratamento com gelatina foi eficiente para remoção de proantocianidinas, enquanto que o tratamento enzimático foi mais eficiente na redução de taninos hidrolisáveis. Os produtos obtidos não apresentaram diferenças visuais. Estudo comparativo de pré-viabilidade econômica mostrou que o investimento de capital para obtenção do suco de caju clarificado com enzima é menor que para o suco clarificado com gelatina. Entretanto, o custo de produção do suco de caju clarificado com gelatina é menor devido ao preço elevado da enzima tanase. COMPARISION OF THE CASHEW APPLE (Anacardium occidentale L.) JUICE CLARIFICATION WITH TANNASE AND GELATIN Abstract Tannase and gelatin were compared for treatment of cashew apple pulp aiming to reduce turbidity and tannin content. The results indicated that the decrease in concentrations of total tannin, hydrolysable tannin, proanthocyanidin, and turbidity was 39%, 50%, 32% and 94% for juices treated with gelatin and 46%, 88%, 2% and 88% for pulp treated with tannase, respectively. In this way the treatment with gelatin was more efficient to remove proanthocyanidin, whereas enzymatic ones was better for hydrolysable tannin decrease. The obtained products didnt present visual differences. The comparative economic analysis for the cashew-apple juice production showed that the capital investment for the enzymatic clarification is lower than for the conventional clarification process, using gelatin. Although, the cost of clarified cashew apple juice using gelatin is lower due to the high cost of the enzyme tannase

Immobilization and stabilization of the endo-1,4-beta-xylanase of Malbranchea pulchella for production of the xylooligosaccharides

Over the last few years, the lignocellulosic biorefinery concept has been extended beyond the application of biofuel production. Innovative and efficient technologies for lignin, cellulose, and hemicellulose fractionation allow the implementation of integrated processes for the co-production of bioenergy and higher value-added bioproducts. Among the different approaches, the use of Endo-1,4--xylanases (EC 3.2.1.8) in the hydrolysis of rich-xylan feedstocks has increased in the integrated process to produce fermentable and xylooligosaccharides (XOS). Nowadays, XOS has been preferentially used as prebiotic components in the development of new functional foods for presenting additional biological benefits such as antioxidant, inflammatory, and immunomodulatory activities. In the current work, we immobilized an endo-1,4-beta-xylanase of Malbranchea pulchella (Mpxyn10) and evaluated its potential in the production of XOS from xylan from various sources. Mpxyn10 was immobilized on agarose-activated supports (Glyoxyl-, MANAE-, GLUT- and PEI-agarose) and commercial Purolite support. Values >90% of immobilization yield were obtained on aminoactivated supports (Purolite, MANAE, and PEI-agarose) after 120 min, and the highest values of activity recovery were obtained for MANAE-MpXyn10 (137%) and Purolite-MpXyn10 (142%) derivatives. MANAE- and Purolite-MpXyn10 derivatives maintained more than 90% of their activity after 24 h of incubation at 70 °C, while the residual activity of free MpXyn10 was only 11%. MpXyn10 derivatives were also active and stable over a wide range of pH (4.0-6.0) and in the presence of furfural and HMF compounds. MpXyn10 derivatives were tested to produce XOS from xylan from various sources. Maximum values of XOS (xylobiose and xylotriose) were found for xylan beechwood at 8.1 mg mL-1, birchwood at 8.6 mg mL-1, and wheat arabinoxylan at 8.9 mg mL-1 after 3 h of reaction, at 50 °C, using Purolite-MpXyn10. This derivative was reused in various reaction cycles, maintaining more than 80% of yield XOS after 6 cycles of reaction. The results obtained in this work provide a basis for the development of applications of immobilized MpXyn10 to XOS production and other high value-added product in the lignocellulosic biorefinery field.The work was supported by the following: FAPESP (São Paulo Research Foundation, grants: 2014/50884 and 2018/07522-6; Process 2020/00081-4) and National Institute of Science and Technology of Bioethanol, INCT, CNPq (grant: 465319/2014-9) and Process 301963/2017-7.info:eu-repo/semantics/publishedVersio

The role of virulence factors in the outcome of staphylococcal peritonitis in CAPD patients

<p>Abstract</p> <p>Background</p> <p>Peritonitis continues to be the most frequent cause of peritoneal dialysis (PD) failure, with an important impact on patient mortality. Gram-positive cocci such as <it>Staphylococcus epidermidis</it>, other coagulase-negative staphylococci (CoNS), and <it>Staphylococcus aureus </it>are the most frequent etiological agents of PD-associated peritonitis worldwide. The objective of the present study was to compare peritonitis caused by <it>S. aureus </it>and CoNS and to evaluate the factors influencing outcome.</p> <p>Methods</p> <p>Records of 86 new episodes of staphylococcal peritonitis that occurred between 1996 and 2000 in the Dialysis unit of a single university hospital were studied (35 due to <it>S. aureus</it>, 24 to <it>S. epidermidis </it>and 27 to other CoNS). The production of slime, lipase, lecithinase, nuclease (DNAse), thermonuclease (TNAse), α- and β-hemolysin, enterotoxins (SEA, SEB, SEC, SED) and toxic shock syndrome toxin-1 (TSST-1) was studied in <it>S. aureus </it>and CoNS. Antimicrobial susceptibility was evaluated based on the minimal inhibitory concentration determined by the E-test. Outcome predictors were evaluated by two logistic regression models.</p> <p>Results</p> <p>The oxacillin susceptibility rate was 85.7% for <it>S. aureus</it>, 41.6% for <it>S. epidermidis</it>, and 51.8% for other CoNS (p = 0.001). Production of toxins and enzymes, except for enterotoxin A and α-hemolysin, was associated with <it>S. aureus </it>episodes (p < 0.001), whereas slime production was positive in 23.5% of CoNS and 8.6% of <it>S. aureus </it>strains (p = 0.0047). The first model did not include enzymes and toxins due to their association with <it>S. aureus</it>. The odds of resolution were 9.5 times higher for <it>S. epidermidis </it>than for <it>S. aureus </it>(p = 0.02) episodes, and were similar for <it>S. epidermidis </it>and other CoNS (p = 0.8). The resolution odds were 68 times higher for non-slime producers (p = 0.001) and were not influenced by oxacillin resistance among vancomycin-treated cases (p = 0.89). In the second model, the resolution rate was similar for <it>S. aureus </it>and <it>S. epidermidis </it>(p = 0.70), and slime (p = 0.001) and α-hemolysin (p = 0.04) production were independent predictors of non-resolution.</p> <p>Conclusion</p> <p>Bacterial species and virulence factors rather than antibiotic resistance influence the outcome of staphylococcal peritonitis.</p

Uso de árvores nativas em pastagens agroecológicas

O conhecimento tradicional tem sido a base da parceria entre o Centro de Tecnologias Alternativas, as organizações dos agricultores familiares da Zona da Mata de Minas Gerais e as Universidades Federais de Viçosa e, mais recentemente, de Lavras. O objetivo desse trabalho foi identificar o conhecimento tradicional sobre os usos comuns de árvores nativas em pastagens de famílias agricultoras dos municípios de Divino e Araponga, aplicando metodologias participativas (observação participante e entrevista semi-estruturada). O principal uso da terra na região é com café e pastagens. Foi observado pelas famílias que os animais comem ramos de Solanum mauritianum, Senna macranthera, Aegiphila sellowiana e Inga edulis. De acordo com as famílias, a maioria das árvores já estava na pastagem antes do capim. É necessário aprofundamento que dialogue com o aprendizado de famílias agricultoras.Traditional knowledge has been the main base of the partnership among the Center of Alternative Technologies, the organizations of family farmers of Zona da Mata of Minas Gerais and the Federal Universities of Viçosa and, more recently, of Lavras. The objective was to identify the traditional knowledge about the common uses of native trees in the pastures of the properties of family farmers in the municipalities of Divino and Araponga, applying qualitative methodologies (participant observation and semi-structured interviews). The land use in the region is mainly coffee and pastures. Was observed by the families that the animals feed themselves with branches of Solanum mauritianum, Senna macranthera, Aegiphila sellowiana and Inga edulis. According to the families the majority of the trees was already in the field before the grass. It is necessary to deep the dialogue to keep leaning and exchange knowledge with smallholders families.Eje A1 Sistemas de producción de base agroecológica (Trabajos científicos)Facultad de Ciencias Agrarias y Forestale

Seasonal variation and antimicrobial activity of Myrcia myrtifolia essential oils

This work reports the seasonal variation of the composition of leaf volatile oils and the composition of volatile oils from flowers and fruits of Myrcia myrtifolia DC harvested in the sand dunes of Salvador, Bahia, northeastern region of Brazil between 2002 and 2003. The oils were analyzed by GC-FID and GC-MS so that 28 components were identified. alpha-Pinene was predominant in a range from 61.5 to 90.9% in all samples analyzed. The leaf oil collected in October 2002 had their antimicrobial properties tested against six bacteria, two yeasts and five filamentous fungi being active against Staphylococcus aureus, methicilin-resistant Staphylococcus aureus, Candida albicans, Cryptococcus neoformans and Aspergillus fumigatus, and showed strongest activity against Microsporum canis and Trichophyton rubrum. The oil displayed moderate toxicity against Artemia salina showing a LC50 of 479.16 µg mL-1

H1N1pdm Influenza Infection in Hospitalized Cancer Patients: Clinical Evolution and Viral Analysis

BACKGROUND: The novel influenza A pandemic virus (H1N1pdm) caused considerable morbidity and mortality worldwide in 2009. The aim of the present study was to evaluate the clinical course, duration of viral shedding, H1N1pdm evolution and emergence of antiviral resistance in hospitalized cancer patients with severe H1N1pdm infections during the winter of 2009 in Brazil. METHODS: We performed a prospective single-center cohort study in a cancer center in Rio de Janeiro, Brazil. Hospitalized patients with cancer and a confirmed diagnosis of influenza A H1N1pdm were evaluated. The main outcome measures in this study were in-hospital mortality, duration of viral shedding, viral persistence and both functional and molecular analyses of H1N1pdm susceptibility to oseltamivir. RESULTS: A total of 44 hospitalized patients with suspected influenza-like illness were screened. A total of 24 had diagnosed H1N1pdm infections. The overall hospital mortality in our cohort was 21%. Thirteen (54%) patients required intensive care. The median age of the studied cohort was 14.5 years (3-69 years). Eighteen (75%) patients had received chemotherapy in the previous month, and 14 were neutropenic at the onset of influenza. A total of 10 patients were evaluated for their duration of viral shedding, and 5 (50%) displayed prolonged viral shedding (median 23, range=11-63 days); however, this was not associated with the emergence of a resistant H1N1pdm virus. Viral evolution was observed in sequentially collected samples. CONCLUSIONS: Prolonged influenza A H1N1pdm shedding was observed in cancer patients. However, oseltamivir resistance was not detected. Taken together, our data suggest that severely ill cancer patients may constitute a pandemic virus reservoir with major implications for viral propagation

Interaction of leptospira elongation factor tu with plasminogen and complement factor h: a metabolic leptospiral protein with moonlighting activities

The elongation factor Tu (EF-Tu), an abundant bacterial protein involved in protein synthesis, has been shown to display moonlighting activities. Known to perform more than one function at different times or in different places, it is found in several subcellular locations in a single organism, and may serve as a virulence factor in a range of important human pathogens. Here we demonstrate that Leptospira EF-Tu is surface-exposed and performs additional roles as a cell-surface receptor for host plasma proteins. It binds plasminogen in a dose-dependent manner, and lysine residues are critical for this interaction. Bound plasminogen is converted to active plasmin, which, in turn, is able to cleave the natural substrates C3b and fibrinogen. Leptospira EF-Tu also acquires the complement regulator Factor H (FH). FH bound to immobilized EF-Tu displays cofactor activity, mediating C3b degradation by Factor I (FI). In this manner, EF-Tu may contribute to leptospiral tissue invasion and complement inactivation. To our knowledge, this is the first description of a leptospiral protein exhibiting moonlighting activitiesFAPESP, 00/11624-