Pesquisa SciELO

Processos de desidratação e de rehidratação de cogumelos da espécie Pleurotus ostreatus foram avaliados neste trabalho. Os cogumelos foram desidratados a 40, 50 e 60 ºC, com umidade relativa do ar de 75 %. O processo de rehidratação foi avaliado para diferentes temperaturas de água de imersão (25, 55 e 85 ºC) e diferentes tempos de imersão (30, 75 e 120 minutos). A melhor temperatura de secagem foi 40 ºC, levando em consideração a melhor rehidratação dos (mais) cogumelos desidratados nesta temperatura. A rehidratação pode ser feita em água a temperatura ambiente, por 30 minutos. Isotermas de sorção de umidade de amostras foram determinadas a 30, 40 e 50 ºC.Tanto o modelo de GAB quanto o de BET representaram satisfatoriamente os dados experimentais de isoterma de sorção de umidade.

Dehydration and rehydration processes of Pleurotus ostreatus fruiting bodies were investigated in this work. Mushroom samples were dehydrated at 40, 50 and 60 ºC, using drying air with relative humidity of 75 %. The rehydration was investigated at different temperatures of immersion water (25, 55 and 85 ºC) and different immersion times (30, 75 and 120 minutes). The best rehydration occurred for the samples dried at 40 ºC. The rehydration could be done in water at room (mais) temperature, during 30 minutes. Water sorption isotherms of samples were determined at 30, 40 and 50 ºC. Both GAB and BET models satisfactorily represented the experimental data of moisture sorption of dried mushrooms.

OBJECTIVE: The objective of this study was to present special clinical and laboratory features of 294 cases of mushroom poisoning. MATERIALS AND METHODS: In this retrospective study, 294 patients admitted to the Pediatric and Adult Emergency, Internal Medicine and ICU Departments of Cumhuriyet University Hospital were investigated. RESULTS: Of 294 patients between the ages of 3 and 72 (28.97 ± 19.32), 173 were female, 121 were male and 90 were under the age of 16 years. (mais) One hundred seventy-three patients (58.8%) had consumed the mushrooms in the early summer. The onset of mushroom toxicity symptoms was divided into early (within 6 h after ingestion) and delayed (6 h to 20 d). Two hundred eighty-eight patients (97.9%) and six (2.1%) patients had early and delayed toxicity symptoms, respectively. The onset of symptoms was within two hours for 101 patients (34.3%). The most common first-noticed symptoms were in the gastrointestinal system. The patients were discharged within one to ten days. Three patients suffering from poisoning caused by wild mushrooms died from fulminant hepatic failure. CONCLUSION: Education of the public about the consumption of mushrooms and education of health personnel working in health centers regarding early treatment and transfer to hospitals with appropriate facilities are important for decreasing the mortality.

Foods with added physiologically-active food components (PAC) are receiving special attention by their potential in disease prevention and health promotion. Additional intake of any nutrient might be achieved by the application of vacuum impregnation technique to fruits and vegetables. Viability of mushroom as matrix for the incorporation of calcium was then evaluated. It was found that, due to the high impregnated liquid fraction observed (17 - 40 %), the calcium incorpo (mais) rated in 100 g of mushroom would satisfy about 24 - 32 % of the Adequate Intake (AI). Thus, there would seem to be much potential for the introduction of high Ca2+ concentration in mushroom tissue through vacuum impregnation, combating the widespread Ca2+ deficiencies that occur in human populations. Although mechanical properties are affected by the vacuum treatment, similar or greater mushroom softening is produced during post-harvest storage or commercial thermal processing.

From the ethyl acetate extract obtained from the methanol extract of the mushroom Pleurotus sajor-cajú, ten compounds conforming the triterpenic fraction were isolated by means of chromatographic techniques like CC and PTLC, and were identified by their MS as: Ergosta-2,5,7,9(1 l),22-pentaene, Ergosta-5,7,9(1 1),22-tetraen-ß-ol, Ergosta-5á,8á-epidioxy-6,22-dien-3R-ol (ergosteryl peroxide), Ergosta-5,7,22-trien-3R-ol (Ergosterol), Ergosta-7,22-dien-3R-ol, 19-Norergosta (mais) -5,7,9,22,tetraen-ß-ol (Neoergosterol), Ergosta-7-en-3R-ol, Ergosta-3ß-5á,6ß-trihydroxy-7,22-diene (Cerevisterol), Ergosta-4,6,8(14),22-tetraen-3-one and Ergosta-4,6,15(16),22-tetraen-3-one. Likewise, three fatty acids were found and identified as palmitic acid, linoleic acid and stearic acid.

Agaricus blazei Murrill, popularly known as the sun mushroom, is a native mushroom in SP, Brazil, that has been widely used in the treatment of cancer and many other pathologies in different parts of the world. A water-soluble protein-polysaccharide complex (1 -> 6)beta-D-glucan has been isolated from its fruiting body that showed immune-modulation activity. From organic extracts, linoleic acid has been isolated and determined to be the main substance with antimutagenic a (mais) ctivity. Using both the micronucleus (MN) and comet (single cell microgel electrophoresis) assays, this study determined the genotoxic and antigenotoxic potential of A. blazei (AB) obtained from commercial sources or the following strains: a) strains AB 97/29 (young and sporulated phases); b) a mixture taken from AB 96/07, AB 96/09 and AB 97/11 strains; and c) commercial mushrooms from Londrina, PR and Piedade, SP, designated as AB PR and AB SP, respectively. The extracts from these mushrooms were isolated in chloroform:methanol (3:1) and used in vitro at three different concentrations. V79 cells (Chinese hamster lung cells) were exposed to the extracts under pre-, simultaneous and post-treatment conditions, combined with methyl methanesulfonate (MMS). Under the circumstances of this study, these organic extracts did not show any genotoxic or mutagenic effects, but did protect cells against the induction of micronuclei by MMS.

Avaliou-se o efeito da substituição de um antibiótico por diferentes níveis do composto exaurido do cogumelo (CEC) Agaricus blazei sobre o desempenho de frangos de corte de 1 a 42 dias de idade. Foram avaliadas sete dietas, seis com adição de CEC (0,0; 0,2; 0,4; 0,6; 0,8 e 1,0%) e uma com antibiótico (avilamicina 10 ppm). Foram utilizados 588 pintos de 1 dia de idade, distribuídos em um delineamento inteiramente casualizado, com seis repetições por dieta (três (mais) por sexo) e 14 aves por unidade experimental. As aves que não receberam qualquer aditivo na dieta apresentaram os piores resultados de desempenho. Níveis de CEC superiores a 0,4% ocasionaram redução gradual no desempenho. O nível de 0,2% de CEC proporcionou o maior ganho de peso e o de 0,21%, a melhor conversão alimentar e o maior consumo de ração. À exceção do rendimento de peito e do rendimento de gordura abdominal, os aditivos não influenciaram os rendimentos de carcaça e dos cortes. O composto exaurido do cogumelo Agaricus blazei pode ser utilizado como aditivo alternativo ao antibiótico no nível de 0,2% da dieta, pois não prejudicou o desempenho produtivo e o rendimento de carcaça das aves.

The effect of the substitution of an antibiotic by different levels of spent mushroom substrate (SMS) of Agaricus blazei on the performance of broiler chicks from 1 to 42 days old was evaluated. Seven diets were evaluated, six with SMS addiction (0.0, 0.2, 0.4, 0.6, 0.8, and 1.0%) and one with antibiotic (avilamycin 10 ppm). A total of 588 one day old chicks was allotted to a complete randomized design, with six replications per diet (three per sex) and 14 birds per exper (mais) imental unit. The birds fed diet with any additive showed the worst performance results. Levels of SMS above 0.4% caused gradual reduction in the performance. The level of 0.2% of SMS provided the highest value of weight gain and of 0.21% promoted the best feed conversion and the highest value of feed intake. With exception of chest and abdominal fat yield, no additive effect on carcass and cuts yield was observed. The spent mushroom substrate of Agaricus blazei can be used as additive alternative to the antibiotic at the level of 0.2% of the diet; therefore it did not harm the productive performance and carcass yields of the birds.

The N-terminal amino acid sequence of an aminopeptidase from Japanese edible mushroom, Grifola frondosa, was reported to have high similarity with that of a serine proteinase from basidiomycete, Agaricus bisporous (Nishiwaki and Hayashi, 2001). The full-length cDNA and the corresponding genomic DNA of the enzyme were cloned, based on the reported N-terminal amino acid sequence. The predicted open reading frame (ORF) of the cloned cDNA, encoding a product of 379 amino acid (mais) s, was expressed in E. coli using pET expression vector. The expressed pro-enzyme (40 kDa) underwent autolysis to produce the mature protein (30 kDa) and a pro-peptide (10 kDa). The mature protein and the pro-peptide remained tightly bound to each other and could not be separated by Ni-NTA metal affinity chromatography or Q-Sepharose ion-exchange chromatography. The enzyme was inactive in the bound form. Upon treatment with subtilisin, the bound pro-peptide was further hydrolyzed and a high serine proteinase activity was recovered. No aminopeptidase activity was detected at any stage of the protein processing. These results clearly indicated that the N-terminal amino acid sequence and the function of the reported aminopeptidase were not derived from the same protein entity and hence caused the structure-function anomaly.

Cinco espécies de cogumelos comestíveis, Lentinula edodes, Pleurotus ostreatus, Pholiota nameko, Macrolepiota bonaerensis e Agaricus blazei foram avaliadas quanto ao seu potencial em inibir o crescimento "in vitro" da levedura patogênica Candida albicans. Apenas a espécie L. edodes apresentou efeito fungistático sobre este patógeno humano. O composto inibitório foi produzido intra e extracelularmente em cultivo submerso de L. edodes e também estava presente em bas (mais) idiocarpos frescos e desidratados do cogumelo. O composto fungistático é termossensível e perde sua atividade após 72 horas.

Five species of edible mushrooms, Lentinula edodes, Pleurotus ostreatus, Pholiota nameko, Macrolepiota bonaerensis and Agaricus blazei, were tested for their potential to inhibit the in vitro growth of the pathogenic yeast Candida albicans. Only L. edodes had a fungistatic effect on this human pathogen. The inhibitory compound was produced intra and extracellularly in submersed L. edodes culture, and was also present in fresh and dehydrated mushroom basidiocarps. The fungistatic compound was heat sensitive and lost activity after 72 hours.

Agaricus blazei Murill is a native Brazilian mushroom which functions primarily as an anticancer substance in transplanted mouse tumors. However, the mechanism underlying this function of A. blazei Murill remains obscure. The present study was carried out to investigate the effect of fraction FA-2-b-ß, an RNA-protein complex isolated from A. blazei Murill, on human leukemia HL-60 cells in vitro. Typical apoptotic characteristics were determined by morphological methods u (mais) sing DNA agarose gel electrophoresis and flow cytometry. The growth suppressive effect of fraction FA-2-b-ß on HL-60 cells in vitro occurred in a dose- (5-80 µg/mL) and time-dependent (24-96 h) manner. The proliferation of HL-60 cells (1 x 10(5) cells/mL) treated with 40 µg/mL of fraction FA-2-b-ß for 24-96 h and with 5-80 µg/mL for 96 h resulted in inhibitory rates ranging from 8 to 54.5%, and from 4.9 to 86.3%, respectively. Both telomerase activity determined by TRAP-ELISA and mRNA expression of the caspase-3 gene detected by RT-PCR were increased in HL-60 cells during fraction FA-2-b-ß treatment. The rate of apoptosis correlated negatively with the decrease of telomerase activity (r = 0.926, P < 0.05), but correlated positively with caspase-3 mRNA expression (r = 0.926, P < 0.05). These data show that fraction FA-2-b-ß can induce HL-60 cell apoptosis and that the combined effect of down-regulation of telomerase activity and up-regulation of mRNA expression of the caspase-3 gene could be the primary mechanism of induction of apoptosis. These findings provide strong evidence that fraction FA-2-b-ß could be of interest for the clinical treatment of acute leukemia.

O gene que codifica uma quitinase (EC 3.2.1.14) foi isolado de Ewingella americana, recentemente descrita como patógeno do cogumelo Agaricus bisporus. Este gene, denominado chiA (EMBL/Genebank/DDBJ número de acesso X9061), foi clonado e selecionado a partir de livraria genômica construída por digestão do DNA de E. americana com HindIII e ligação em plasmídio de expressão em E. coli, utilizando meio seletivo contendo quitina carboximetilada, corada com "remazol br (mais) illiant violet'' para seleção de clones. O gene chiA apresenta uma ORF de 918 bp, código terminador TAA, tendo o tamanho do polipeptídeo sido calculado como 33,2 kDa, o qual corresponde ao tamanho de 33 kDa da endoquitinase previamente purificada de E. americana. A seqüência deduzida de aminoácidos apresenta 33% de identidade com a quitinase II de Aeromonas sp. No. 10S-24 e 7,8% de identidade com quitinase de Saccharopolyspora erythraeus. Baixa homologia com outras quitinases foi observada. A seqüência deduzida de aminoácidos de chiA não apresenta sinal típico de N-terminal e também não apresenta típico sítio de ligação com quitina nem unidades de homologia à fibronectina do tipo III, comuns a muitas quitinases bacterianas. Existe a possibilidade de que esta quitinase não seja primariamente adaptada para mineralização de quitina pré-formada no ambiente, sendo discutida a digestão e quebra de quitina nascente, no contexto de doenças de cogumelos.

We have isolated a gene encoding a chitinase (EC 3.2.1.14) from Ewingella americana, a recently described pathogen of the mushroom Agaricus bisporus. This gene, designated chiA (EMBL/Genbank/DDBJ accession number X90562), was cloned by expression screening of a plasmid-based E. americana HindIII genomic library in Escherichia coli using remazol brilliant violet-stained carboxymethylated chitin incorporated into selective medium. The chiA gene has a 918-bp ORF, terminated (mais) by a TAA codon, with a calculated polypeptide size of 33.2 kDa, likely corresponding to a previously purified and characterised 33-kDa endochitinase from E. americana. The deduced amino acid sequence shares 33% identity with chitinase II from Aeromonas sp. No. 10S-24 and 7.8% identity with a chitinase from Saccharopolyspora erythraeus. Homology to other chitinase sequences was otherwise low. The peptide sequence deduced from chiA lacks a typical N-terminal signal sequence and also lacks the chitin binding and type III fibronectin homology units common to many bacterial chitinases. The possibility that this chitinase is not primarily adapted for the environmental mineralisation of pre-formed chitin, but rather for the breakdown of nascent chitin, is discussed in the context of mushroom disease.