RESUMO
Esfenvalerate biodegradation by marine-derived fungi is reported here. Esfenvalerate (S,S-fenvalerate) and its main metabolites [3-phenoxybenzaldehyde (PBAld), 3-phenoxybenzoic acid (PBAc), 3-phenoxybenzyl alcohol (PBAlc), and 2-(4-chlorophenyl)-3-methylbutyric acid (CLAc)] were quantitatively analyzed by a validated method in triplicate experiments. All the strains (Penicillium raistrickii CBMAI 931, Aspergillus sydowii CBMAI 935, Cladosporium sp. CBMAI 1237, Microsphaeropsis sp. CBMAI 1675, Acremonium sp. CBMAI 1676, Westerdykella sp. CBMAI 1679, and Cladosporium sp. CBMAI 1678) were able to degrade esfenvalerate, however, with different efficiencies. Initially, 100 mg L(-1) esfenvalerate (Sumidan 150SC) was added to each culture in 3 % malt liquid medium. Residual esfenvalerate (64.8-95.2 mg L(-1)) and the concentrations of PBAc (0.5-7.4 mg L(-1)), ClAc (0.1-7.5 mg L(-1)), and PBAlc (0.2 mg L(-1)) were determined after 14 days. In experiments after 7, 14, 21, and 28 days of biodegradation with the three most efficient strains, increasing concentrations of the toxic compounds PBAc (2.7-16.6 mg L(-1), after 28 days) and CLAc (6.6-13.4 mg L(-1), after 28 days) were observed. A biodegradation pathway was proposed, based on HPLC-ToF results. The biodegradation pathway includes PBAld, PBAc, PBAlc, ClAc, 2-hydroxy-2-(3-phenoxyphenyl)acetonitrile, 3-(hydroxyphenoxy)benzoic acid, and methyl 3-phenoxy benzoate. Marine-derived fungi were able to biodegrade esfenvalerate in a commercial formulation and showed their potential for future bioremediation studies in contaminated soils and water bodies.
Assuntos
Acremonium/metabolismo , Aspergillus/metabolismo , Cladosporium/metabolismo , Nitrilas/metabolismo , Penicillium/metabolismo , Praguicidas/metabolismo , Piretrinas/metabolismo , Poluentes Químicos da Água/metabolismo , Benzaldeídos/metabolismo , Benzoatos/metabolismo , Álcoois Benzílicos/metabolismo , Biodegradação Ambiental , Concentração de Íons de Hidrogênio , Hidrólise , Cinética , Poluentes do Solo/metabolismoRESUMO
Benzyl alcohol and other benzenoid-derived metabolites of particular importance in plants confer floral and fruity flavors to wines. Among the volatile aroma components in Vitis vinifera grape varieties, benzyl alcohol is present in its free and glycosylated forms. These compounds are considered to originate from grapes only and not from fermentative processes. We have found increased levels of benzyl alcohol in red Tannat wine compared to that in grape juice, suggesting de novo formation of this metabolite during vinification. In this work, we show that benzyl alcohol, benzaldehyde, p-hydroxybenzaldehyde, and p-hydroxybenzyl alcohol are synthesized de novo in the absence of grape-derived precursors by Hanseniaspora vineae. Levels of benzyl alcohol produced by 11 different H. vineae strains were 20-200 times higher than those measured in fermentations with Saccharomyces cerevisiae strains. These results show that H. vineae contributes to flavor diversity by increasing grape variety aroma concentration in a chemically defined medium. Feeding experiments with phenylalanine, tryptophan, tyrosine, p-aminobenzoic acid, and ammonium in an artificial medium were tested to evaluate the effect of these compounds either as precursors or as potential pathway regulators for the formation of benzenoid-derived aromas. Genomic analysis shows that the phenylalanine ammonia-lyase (PAL) and tyrosine ammonia lyase (TAL) pathways, used by plants to generate benzyl alcohols from aromatic amino acids, are absent in the H. vineae genome. Consequently, alternative pathways derived from chorismate with mandelate as an intermediate are discussed.
Assuntos
Benzaldeídos/metabolismo , Álcoois Benzílicos/metabolismo , Aromatizantes/metabolismo , Hanseniaspora/metabolismo , Vitis/microbiologia , Vinho/análise , Benzaldeídos/análise , Álcoois Benzílicos/análise , Fermentação , Aromatizantes/análise , Hanseniaspora/genética , Vitis/metabolismoRESUMO
Bacteria have evolved various mechanisms to extract utilizable substrates from available resources and consequently acquire fitness advantage over competitors. One of the strategies is the exploitation of cryptic cellular functions encoded by genetic systems that are silent under laboratory conditions, such as the bgl (β-glucoside) operon of E. coli. The bgl operon of Escherichia coli, involved in the uptake and utilization of aromatic β-glucosides salicin and arbutin, is maintained in a silent state in the wild type organism by the presence of structural elements in the regulatory region. This operon can be activated by mutations that disrupt these negative elements. The fact that the silent bgl operon is retained without accumulating deleterious mutations seems paradoxical from an evolutionary view point. Although this operon appears to be silent, specific physiological conditions might be able to regulate its expression and/or the operon might be carrying out function(s) apart from the utilization of aromatic β-glucosides. This is consistent with the observations that the activated operon confers a Growth Advantage in Stationary Phase (GASP) phenotype to Bgl+ cells and exerts its regulation on at least twelve downstream target genes.
Assuntos
Escherichia coli/enzimologia , Escherichia coli/genética , Regulação da Expressão Gênica , beta-Glucosidase/genética , beta-Glucosidase/metabolismo , Arbutina/metabolismo , Álcoois Benzílicos/metabolismo , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/metabolismo , Glucosídeos/metabolismo , ÓperonRESUMO
Bacteria have evolved various mechanisms to extract utilizable substrates from available resources and consequently acquire fitness advantage over competitors. One of the strategies is the exploitation of cryptic cellular functions encoded by genetic systems that are silent under laboratory conditions, such as the bgl (β-glucoside) operon of E. coli. The bgl operon of Escherichia coli, involved in the uptake and utilization of aromatic β-glucosides salicin and arbutin, is maintained in a silent state in the wild type organism by the presence of structural elements in the regulatory region. This operon can be activated by mutations that disrupt these negative elements. The fact that the silent bgl operon is retained without accumulating deleterious mutations seems paradoxical from an evolutionary view point. Although this operon appears to be silent, specific physiological conditions might be able to regulate its expression and/or the operon might be carrying out function(s) apart from the utilization of aromatic β-glucosides. This is consistent with the observations that the activated operon confers a Growth Advantage in Stationary Phase (GASP) phenotype to Bgl+ cells and exerts its regulation on at least twelve downstream target genes.
Assuntos
Escherichia coli/enzimologia , Escherichia coli/genética , Regulação da Expressão Gênica , beta-Glucosidase/genética , beta-Glucosidase/metabolismo , Arbutina/metabolismo , Álcoois Benzílicos/metabolismo , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/metabolismo , Glucosídeos/metabolismo , ÓperonRESUMO
KEY MESSAGE: An RNAseq-based analysis of the cassava plants inoculated with Xam allowed the identification of transcriptional upregulation of genes involved in jasmonate metabolism, phenylpropanoid biosynthesis and putative targets for a TALE. Cassava bacterial blight, a disease caused by the gram-negative bacterium Xanthomonas axonopodis pv. manihotis (Xam), is a major limitation to cassava production worldwide and especially in developing countries. The molecular mechanisms underlying cassava susceptibility to Xam are currently unknown. To identify host genes and pathways leading to plant susceptibility, we analyzed the transcriptomic responses occurring in cassava plants challenged with either the non-pathogenic Xam strain ORST4, or strain ORST4(TALE1 Xam ) which is pathogenic due to the major virulence transcription activator like effector TALE1 Xam . Both strains triggered similar responses, i.e., induction of genes related to photosynthesis and phenylpropanoid biosynthesis, and repression of genes related to jasmonic acid signaling. Finally, to search for TALE1 Xam virulence targets, we scanned the list of cassava genes induced upon inoculation of ORST4(TALE1 Xam ) for candidates harboring a predicted TALE1 Xam effector binding element in their promoter. Among the six genes identified as potential candidate targets of TALE1 Xam a gene coding for a heat shock transcription factor stands out as the best candidate based on their induction in presence of TALE1 Xam and contain a sequence putatively recognized by TALE1 Xam .
Assuntos
Perfilação da Expressão Gênica , Manihot/genética , Doenças das Plantas/genética , Xanthomonas axonopodis/crescimento & desenvolvimento , Álcoois Benzílicos/metabolismo , Análise por Conglomerados , Genes de Plantas/genética , Interações Hospedeiro-Patógeno , Manihot/microbiologia , Análise de Sequência com Séries de Oligonucleotídeos , Fotossíntese/genética , Doenças das Plantas/microbiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Análise de Componente Principal , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Virulência , Xanthomonas axonopodis/patogenicidade , Xanthomonas axonopodis/fisiologiaRESUMO
Bacteria have evolved various mechanisms to extract utilizable substrates from available resources and consequently acquire fitness advantage over competitors. One of the strategies is the exploitation of cryptic cellular functions encoded by genetic systems that are silent under laboratory conditions, such as the bgl (ß-glucoside) operon of E. coli. The bgl operon of Escherichia coli, involved in the uptake and utilization of aromatic ß-glucosides salicin and arbutin, is maintained in a silent state in the wild type organism by the presence of structural elements in the regulatory region. This operon can be activated by mutations that disrupt these negative elements. The fact that the silent bgl operon is retained without accumulating deleterious mutations seems paradoxical from an evolutionary view point. Although this operon appears to be silent, specific physiological conditions might be able to regulate its expression and/or the operon might be carrying out function(s) apart from the utilization of aromatic ß-glucosides. This is consistent with the observations that the activated operon confers a Growth Advantage in Stationary Phase (GASP) phenotype to Bgl(+) cells and exerts its regulation on at least twelve downstream target genes.
Assuntos
Escherichia coli/enzimologia , Escherichia coli/genética , Regulação da Expressão Gênica , beta-Glucosidase/genética , beta-Glucosidase/metabolismo , Arbutina/metabolismo , Álcoois Benzílicos/metabolismo , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/metabolismo , Glucosídeos/metabolismo , ÓperonRESUMO
The neolignan, burchellin, a natural compound that reduces urine excretion in larvae of the bloodsucking bug, Rhodnius prolixus, a vector of Chagas' disease, is rapidly degraded in the hemolymph of the insect. The main product that accumulates in this tissue has been shown to be piperonyl alcohol. Other catabolites have been identified by GC-MS analysis.
Assuntos
Benzofuranos/sangue , Hemolinfa/metabolismo , Lauraceae , Praguicidas/farmacologia , Extratos Vegetais/metabolismo , Rhodnius/metabolismo , Animais , Benzofuranos/metabolismo , Álcoois Benzílicos/metabolismo , Doença de Chagas/prevenção & controle , Relação Estrutura-AtividadeRESUMO
Molecular typing and virulence markers were used to evaluate the genetic profiles and virulence potential of 106 Yersinia enterocolitica strains. Of these strains, 71 were bio-serotype 4/O : 3, isolated from human and animal clinical material, and 35 were of biotype 1A or 2 and of diverse serotypes, isolated from food in Brazil between 1968 and 2000. Drug resistance was also investigated. All the strains were resistant to three or more drugs. The isolates showed a virulence-related phenotype in the aesculin, pyrazinamidase and salicin tests, except for the food isolates, only two of which were positive for these tests. For the other phenotypic virulence determinants (autoagglutination, Ca(++) dependence and Congo red absorption), the strains showed a diverse behaviour. The inv, ail and ystA genes were detected in all human and animal strains, while all the food isolates were positive for inv, and 3 % of them positive for ail and ystA. The presence of virF was variable in the three groups of strains. The strains were better discriminated by PFGE than by enterobacterial repetitive intergenic consensus PCR (ERIC-PCR). A higher genomic similarity was observed among the 4/O : 3 strains, isolated from human and animal isolates, than among the food strains, with the exception of two food strains possessing the virulence genes and grouped close to the 4/O : 3 strains by ERIC-PCR. Unusually, the results revealed the virulence potential of a bio-serotype 1A/O : 10 strain, suggesting that food contaminated with Y. enterocolitica biotype 1A may cause infection. This also suggests that ERIC-PCR may be used as a tool to reveal clues about the virulence potential of Y. enterocolitica strains. Furthermore, the results also support the hypothesis that animals may act as reservoirs of Y. enterocolitica for human infections in Brazil, an epidemiological aspect that has not been investigated in this country, confirming data from other parts of the world.
Assuntos
Microbiologia de Alimentos , Yersiniose/microbiologia , Yersinia enterocolitica/classificação , Testes de Aglutinação , Amidoidrolases , Animais , Álcoois Benzílicos/metabolismo , Brasil/epidemiologia , Vermelho Congo/metabolismo , DNA Bacteriano/química , DNA Bacteriano/genética , Eletroforese em Gel de Campo Pulsado , Esculina/metabolismo , Glucosídeos , Humanos , Testes de Sensibilidade Microbiana , Reação em Cadeia da Polimerase , Virulência , Fatores de Virulência/química , Fatores de Virulência/genética , Yersiniose/epidemiologia , Yersinia enterocolitica/genética , Yersinia enterocolitica/isolamento & purificação , Yersinia enterocolitica/patogenicidadeRESUMO
Four strains of a novel yeast species were isolated from laboratory nests of the leaf-cutting ant Atta sexdens in Brazil. Three strains were found in older sponges and one was in a waste deposit in the ant nests. Sequencing of the D1/D2 region of the large-subunit rRNA gene showed that the novel species, named Sympodiomyces attinorum sp. nov., is phylogenetically related to Sympodiomyces parvus. Unlike Sympodiomyces parvus, Sympodiomyces attinorum can ferment glucose, assimilate methyl alpha-D-glucoside, salicin and citrate, and grow at 37 degrees C, thus enabling these two species to be distinguished. Differentiation from other related species is possible on the basis of other growth characteristics. The type strain of Sympodiomyces attinorum is UNESP-S156T (= CBS 9734T = NRRL Y-27639T).
Assuntos
Formigas/microbiologia , Saccharomycetales/classificação , Saccharomycetales/isolamento & purificação , Animais , Álcoois Benzílicos/metabolismo , Brasil , Ácido Cítrico/metabolismo , Impressões Digitais de DNA , DNA Fúngico/química , DNA Fúngico/isolamento & purificação , DNA Ribossômico/química , DNA Ribossômico/isolamento & purificação , Fermentação , Genes de RNAr/genética , Glucose/metabolismo , Glucosídeos , Metilglucosídeos/metabolismo , Dados de Sequência Molecular , Filogenia , RNA Fúngico/genética , Saccharomycetales/citologia , Saccharomycetales/fisiologia , Análise de Sequência de DNA , TemperaturaRESUMO
Strains (105) of Yersinia pseudotuberculosis isolated in Brazil between 1982 and 1990 were bio-serotyped. They were also studied for plasmid profile, autoagglutination and calcium dependence at 37 degrees C, Congo red uptake, pyrazinamidase activity, esculin hydrolysis, salicin fermentation and drug sensitivity: 95.24% were biotype 2, serogroup O:3; 2.86% were biotype 1, serogroup O:1; and 1.90% were biotype 2, non-agglutinable. Plasmids were found in 77.14% of the strains (one in each strain). There was total correlation between the presence of the virulence plasmid and autoagglutination, calcium dependence at 37 degrees C and Congo red uptake. The esculin, salicin and pyrazinamidase tests were not efficient in differentiating pathogenic from non-pathogenic Y. pseudotuberculosis isolates. All strains were highly sensitive to the drugs used. These results indicate that Y. pseudotuberculosis is a potential pathogen for humans in Brazil, especially because the bio-serogroups detected among animals are those most frequently associated with human diseases.