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1.
BMC Infect Dis ; 20(1): 697, 2020 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-32962658

RESUMO

BACKGROUND: The microbiota of the respiratory tract has an important role in maintaining respiratory health. However, little is known on the respiratory microbiota in asthmatic patients among Middle Eastern populations. This study investigated the respiratory microbiota composition and functionality associated with asthma in Emirati subjects. METHODS: We performed 16S rRNA and ITS2-gene based microbial profiling of 40 expectorated sputum samples from adult and pediatric Emirati individuals averaging 52 and 7 years of age, respectively with or without asthma. RESULTS: We report bacterial difference belonging to Bacteroidetes, Firmicutes, Fusobacteria and Proteobacteria phyla between asthmatic and non-asthmatic controls. Similarly, fungal difference belonging to Ascomycota, Basidiomycota phyla and other unclassified fungi. Differential abundance testing among asthmatic individuals with relation to Asthma Control Test show a significant depletion of Penicillium aethiopicum and Alternaria spp., among poorly controlled asthmatics. Moreover, data suggest a significant expansion of Malassezia spp. and other unclassified fungi in the airways of those receiving steroids and leukotriene receptor antagonists' combination therapy, in contrast to those receiving steroids alone. Functional profiling from 16S data showed marked differences between pediatric asthmatic and non-asthmatic controls, with pediatric asthmatic patients showing an increase in amino acid (p-value < 5.03 × 10- 7), carbohydrate (p-value < 4.76 × 10- 7), and fatty acid degradation (p-value < 6.65 × 10- 7) pathways, whereas non-asthmatic controls are associated with increase in amino acid (p-value < 8.34 × 10- 7), carbohydrate (p-value < 3.65 × 10- 7), and fatty acid (p-value < 2.18 × 10- 6) biosynthesis pathways in concordance with enterotype composition. CONCLUSIONS: These differences provide an insight into respiratory microbiota composition in Emirati population and its possible role in the development of asthma early in life. This study provides important information that may eventually lead to the development of screening biomarkers to predict early asthma development and novel therapeutic approaches.


Assuntos
Asma/microbiologia , Bactérias , Fungos , Microbiota/fisiologia , Sistema Respiratório/microbiologia , Adolescente , Adulto , Aminoácidos/metabolismo , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , Metabolismo dos Carboidratos , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Fungos/genética , Fungos/isolamento & purificação , Fungos/metabolismo , Humanos , Masculino , Microbiota/genética , Pessoa de Meia-Idade , RNA Ribossômico 16S/genética , Escarro/microbiologia , Emirados Árabes Unidos , Adulto Jovem
2.
Nat Commun ; 11(1): 4897, 2020 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-32994415

RESUMO

Soil microbial respiration is an important source of uncertainty in projecting future climate and carbon (C) cycle feedbacks. However, its feedbacks to climate warming and underlying microbial mechanisms are still poorly understood. Here we show that the temperature sensitivity of soil microbial respiration (Q10) in a temperate grassland ecosystem persistently decreases by 12.0 ± 3.7% across 7 years of warming. Also, the shifts of microbial communities play critical roles in regulating thermal adaptation of soil respiration. Incorporating microbial functional gene abundance data into a microbially-enabled ecosystem model significantly improves the modeling performance of soil microbial respiration by 5-19%, and reduces model parametric uncertainty by 55-71%. In addition, modeling analyses show that the microbial thermal adaptation can lead to considerably less heterotrophic respiration (11.6 ± 7.5%), and hence less soil C loss. If such microbially mediated dampening effects occur generally across different spatial and temporal scales, the potential positive feedback of soil microbial respiration in response to climate warming may be less than previously predicted.


Assuntos
Carbono/análise , Metagenoma/genética , Microbiota/fisiologia , Microbiologia do Solo , Solo/química , Aclimatação/genética , Archaea/genética , Archaea/isolamento & purificação , Archaea/metabolismo , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , Carbono/metabolismo , Ciclo do Carbono , Celulose/metabolismo , DNA Ambiental/genética , DNA Ambiental/isolamento & purificação , Fungos/genética , Fungos/isolamento & purificação , Fungos/metabolismo , Aquecimento Global , Pradaria , Temperatura Alta/efeitos adversos , Metagenômica , Modelos Genéticos , Raízes de Plantas/química , Poaceae/química
3.
Bull Environ Contam Toxicol ; 105(4): 645-649, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32870333

RESUMO

Biosorption has gained increased attention as a reliable and proven technology for the remediation of industrial effluents rich in chromium. The present study was planned to isolate potential fungi from effluents contaminated sites and assess their efficiency for the absorption and reduction of chromium. Two species of Aspergillus and a species of Trichoderma which were isolated from contaminated sites and exhibited resistance to 10 mM of chromium on agar were chosen for the study. A biosorbent was designed by growing these fungal isolates on luffa sponge under shaken condition. The absorption and reduction of chromium, by the designed biosorbent was determined by Atomic Absorption Spectrophotometry and UV Visible Spectrophotometer. Actively growing fungi on luffa sponge showed better absorption (21%-25%) and reduction (28%-35%) capacity when compared to heat killed biosorbent in all fungi tested within 24 h of incubation. Interestingly, there was a liner increase in the absorption and reduction (85%-100%) of chromium by the biosorbent designed by using A. niger.


Assuntos
Cromo/metabolismo , Fungos/metabolismo , Adsorção
4.
Chemosphere ; 254: 126880, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32957287

RESUMO

Electro-bioremediation is a promising technology for remediation of soil contaminated with persistent organic compounds such as polycyclic aromatic hydrocarbons (PAHs). During electro-bioremediation, electrical fields have been shown to increase pollutant degradation. However, it remains unclear whether there is an optimal strength for the electrical field applied that is conductive to the maximum role played by microbes. This study aimed to determine the optimal strength of electric field through the analysis of the effects of different voltages on the microbial community and activity. Four bench-scale experiments with voltages of 0, 1, 2 and 3 V cm-1 were conducted for 90 days in an aged PAH-contaminated soil. The spatiotemporal changes of the soil pH, moisture content and temperature, microbial biomass and community structure, and the degradation extent of PAHs were researched over 90 days. The results indicated that the total microbial biomass and degradation activity were highest at voltages of 2 V cm-1. The concentration of total phospholipid fatty acids, used to quantify soil microbial biomass, reached 65.7 nmol g-1 soil, and the mean degradation extent of PAHs was 44.0%. Similarly, the maximum biomass of actinomycetes, bacteria and fungus also occurred at the voltage of 2 V cm-1. The Gram-positive/Gram-negative and (cy17:0+cy 19:0)/(16:1ω7+18:1ω7) ratios also showed that the intensity of electric field and electrode reactions strongly influenced the microbial community structure. Therefore, to optimize the electro-bioremediation of PAH-contaminated soil, the strength of electric field needs to be selected carefully. This work provides reference for the development of novel electrokinetically enhanced bioremediation processes.


Assuntos
Biodegradação Ambiental , Microbiota , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Bactérias/metabolismo , Biomassa , Fungos/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/análise , Solo/química , Microbiologia do Solo , Poluentes do Solo/análise
5.
Nat Commun ; 11(1): 4864, 2020 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-32978392

RESUMO

The synthesis of customized glycoconjugates constitutes a major goal for biocatalysis. To this end, engineered glycosidases have received great attention and, among them, thioglycoligases have proved useful to connect carbohydrates to non-sugar acceptors. However, hitherto the scope of these biocatalysts was considered limited to strong nucleophilic acceptors. Based on the particularities of the GH3 glycosidase family active site, we hypothesized that converting a suitable member into a thioglycoligase could boost the acceptor range. Herein we show the engineering of an acidophilic fungal ß-xylosidase into a thioglycoligase with broad acceptor promiscuity. The mutant enzyme displays the ability to form O-, N-, S- and Se- glycosides together with sugar esters and phosphoesters with conversion yields from moderate to high. Analyses also indicate that the pKa of the target compound was the main factor to determine its suitability as glycosylation acceptor. These results expand on the glycoconjugate portfolio attainable through biocatalysis.


Assuntos
Tolerância a Medicamentos/fisiologia , Fungos/enzimologia , Fungos/metabolismo , Xilosidases/química , Xilosidases/metabolismo , Biocatálise , Domínio Catalítico , Fungos/efeitos dos fármacos , Glicoconjugados/metabolismo , Glicosídeo Hidrolases/metabolismo , Glicosídeos/química , Glicosilação , Concentração de Íons de Hidrogênio , Cinética , Modelos Moleculares , Mutagênese , Especificidade por Substrato , Talaromyces/enzimologia , Talaromyces/genética , Xilosidases/genética
6.
Int J Food Microbiol ; 334: 108808, 2020 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-32835995

RESUMO

Heat-stable mycotoxins are widely detected in flour and produced by Aspergillus spp., Fusarium spp. and Penicillium spp. Forty different flours purchased in Italy are used to assess potential risk factors via a systematically screening of a number of variables: the type of flour, organic, whole and white wheat, types of packaging (paper, plastic and weight). Fungal recovery and co-occurrence of specific mycotoxins was also assessed. The results showed that flour originated from fruits had a significant higher recovery of fungi, while seed/pseudocereals had the highest mycotoxins detection. Flours originating from organic agriculture are more prone to higher fungal recovery and mycotoxins detection when compared with not-organic flours. Packaging is also important: packaging weighting less than 376 g supports significantly more fungal recovery and the plastic packages was observed to retain more fungi and mycotoxins detection when compared with paper. Recovery measured as Log (CFU/g) of fungal genera is not directly proportional to the amount of mycotoxins. Finally, linear regression and mixed logit regression models show that the mean level of aflatoxins B1 (ng/g on the logarithmic scale) reduces by 0.485 when moving from an organic to a non-organic flour, while a significant increase of 0.369 when moving from paper to a plastic packaging.


Assuntos
Farinha/análise , Farinha/microbiologia , Contaminação de Alimentos/análise , Fungos/isolamento & purificação , Micotoxinas/análise , Embalagem de Alimentos , Fungos/classificação , Fungos/metabolismo , Itália , Agricultura Orgânica , Triticum/microbiologia
7.
Proc Natl Acad Sci U S A ; 117(36): 22061-22067, 2020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32839341

RESUMO

The correct distribution and trafficking of proteins are essential for all organisms. Eukaryotes evolved a sophisticated trafficking system which allows proteins to reach their destination within highly compartmentalized cells. One eukaryotic hallmark is the attachment of a glycosylphosphatidylinositol (GPI) anchor to C-terminal ω-peptides, which are used as a zip code to guide a subset of membrane-anchored proteins through the secretory pathway to the plasma membrane. In fungi, the final destination of many GPI-anchored proteins is their outermost compartment, the cell wall. Enzymes of the Dfg5 subfamily catalyze the essential transfer of GPI-anchored substrates from the plasma membrane to the cell wall and discriminate between plasma membrane-resident GPI-anchored proteins and those transferred to the cell wall (GPI-CWP). We solved the structure of Dfg5 from a filamentous fungus and used in crystallo glycan fragment screening to reassemble the GPI-core glycan in a U-shaped conformation within its binding pocket. The resulting model of the membrane-bound Dfg5•GPI-CWP complex is validated by molecular dynamics (MD) simulations and in vivo mutants in yeast. The latter show that impaired transfer of GPI-CWPs causes distorted cell-wall integrity as indicated by increased chitin levels. The structure of a Dfg5•ß1,3-glycoside complex predicts transfer of GPI-CWP toward the nonreducing ends of acceptor glycans in the cell wall. In addition to our molecular model for Dfg5-mediated transglycosylation, we provide a rationale for how GPI-CWPs are specifically sorted toward the cell wall by using GPI-core glycan modifications.


Assuntos
Parede Celular/metabolismo , Proteínas Fúngicas/metabolismo , Fungos/metabolismo , Glicoproteínas/metabolismo , Glicosilfosfatidilinositóis/metabolismo , Parede Celular/química , Parede Celular/genética , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Fungos/química , Fungos/classificação , Fungos/genética , Glicoproteínas/química , Glicoproteínas/genética , Glicosilfosfatidilinositóis/química , Transporte Proteico
8.
Nat Commun ; 11(1): 3870, 2020 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-32747621

RESUMO

Soils harbor a substantial fraction of the world's biodiversity, contributing to many crucial ecosystem functions. It is thus essential to identify general macroecological patterns related to the distribution and functioning of soil organisms to support their conservation and consideration by governance. These macroecological analyses need to represent the diversity of environmental conditions that can be found worldwide. Here we identify and characterize existing environmental gaps in soil taxa and ecosystem functioning data across soil macroecological studies and 17,186 sampling sites across the globe. These data gaps include important spatial, environmental, taxonomic, and functional gaps, and an almost complete absence of temporally explicit data. We also identify the limitations of soil macroecological studies to explore general patterns in soil biodiversity-ecosystem functioning relationships, with only 0.3% of all sampling sites having both information about biodiversity and function, although with different taxonomic groups and functions at each site. Based on this information, we provide clear priorities to support and expand soil macroecological research.


Assuntos
Biodiversidade , Ecossistema , Microbiologia do Solo , Solo/parasitologia , Animais , Bactérias/classificação , Bactérias/metabolismo , Biomassa , Clima , Fungos/classificação , Fungos/metabolismo , Geografia , Concentração de Íons de Hidrogênio , Nematoides/classificação , Nematoides/metabolismo , Oligoquetos/classificação , Oligoquetos/metabolismo , Solo/química , Temperatura
9.
Ecotoxicol Environ Saf ; 202: 110959, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32800231

RESUMO

Long-term field experiments were performed to evaluate the phytotoxic properties of fungal metabolites in oil-contaminated soil and to assess the impact of contamination on the allelopathic activity of soil mycobiota. Two contrasting soils of Northwest Russia (sandy and loamy podzols) exposed to oil contamination underwent changes in abundance and allelopathic activities of soil fungi. Shifts within the microbial community caused by oil contamination affected not only oil-decomposition rates but also ecotoxicity of contaminated soil. There were significant differences in soil toxicity dynamics between sandy and loamy podzols. Four years after contamination, ecotoxicity of loamy podzol decreased, whereas sandy podzol remained highly toxic even nine years after contamination. The abundance and allelopathic activity of fungi is correlated with hydrocarbon degradation dynamics. The soil fungal community demonstrated high allelopathic activity which decreased over time in fertile loamy podzolic soil, whereas in poor sandy podzolic soil it remained high over the nine-year monitoring period. The results illustrate how oil contamination may influence allelopathic interactions in soil and demonstrate the advantage of using fungal metabolite toxicity test for testing of oil-contaminated soil samples.


Assuntos
Fungos/efeitos dos fármacos , Hidrocarbonetos/toxicidade , Micotoxinas/toxicidade , Petróleo/toxicidade , Microbiologia do Solo , Poluentes do Solo/análise , Animais , Biodegradação Ambiental , Daphnia/efeitos dos fármacos , Daphnia/crescimento & desenvolvimento , Ecotoxicologia , Fungos/metabolismo , Hidrocarbonetos/análise , Micotoxinas/metabolismo , Petróleo/análise , Federação Russa , Solo/química , Testes de Toxicidade , Triticum/efeitos dos fármacos , Triticum/crescimento & desenvolvimento
10.
Nat Commun ; 11(1): 3897, 2020 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-32753587

RESUMO

Lipo-chitooligosaccharides (LCOs) are signaling molecules produced by rhizobial bacteria that trigger the nodulation process in legumes, and by some fungi that also establish symbiotic relationships with plants, notably the arbuscular and ecto mycorrhizal fungi. Here, we show that many other fungi also produce LCOs. We tested 59 species representing most fungal phyla, and found that 53 species produce LCOs that can be detected by functional assays and/or by mass spectroscopy. LCO treatment affects spore germination, branching of hyphae, pseudohyphal growth, and transcription in non-symbiotic fungi from the Ascomycete and Basidiomycete phyla. Our findings suggest that LCO production is common among fungi, and LCOs may function as signals regulating fungal growth and development.


Assuntos
Quitina/análogos & derivados , Quitina/metabolismo , Fungos/crescimento & desenvolvimento , Fungos/metabolismo , Transdução de Sinais/fisiologia , Ascomicetos/crescimento & desenvolvimento , Basidiomycota/crescimento & desenvolvimento , Ecologia , Ácidos Graxos/metabolismo , Micorrizas/fisiologia , Rhizobium/metabolismo , Esporos Fúngicos/crescimento & desenvolvimento , Simbiose/fisiologia
11.
PLoS One ; 15(8): e0237478, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32853208

RESUMO

Paclitaxel as a microtubule-stabilizing agent is widely used for the treatment of a vast range of cancers. Corylus avellana cell suspension culture (CSC) is a promising strategy for paclitaxel production. Elicitation of paclitaxel biosynthesis pathway is a key approach for improving its production in cell culture. However, optimization of this process is time-consuming and costly. Modeling of paclitaxel elicitation process can be helpful to predict the optimal condition for its high production in cell culture. The objective of this study was modeling and forecasting paclitaxel biosynthesis in C. avellana cell culture responding cell extract (CE), culture filtrate (CF) and cell wall (CW) derived from endophytic fungus, either individually or combined treatment with methyl-ß-cyclodextrin (MBCD), based on four input variables including concentration levels of fungal elicitors and MBCD, elicitor adding day and CSC harvesting time, using adaptive neuro-fuzzy inference system (ANFIS) and multiple regression methods. The results displayed a higher accuracy of ANFIS models (0.94-0.97) as compared to regression models (0.16-0.54). The great accordance between the predicted and observed values of paclitaxel biosynthesis for both training and testing subsets support excellent performance of developed ANFIS models. Optimization process of developed ANFIS models with genetic algorithm (GA) showed that optimal MBCD (47.65 mM) and CW (2.77% (v/v)) concentration levels, elicitor adding day (16) and CSC harvesting time (139 h and 41 min after elicitation) can lead to highest paclitaxel biosynthesis (427.92 µg l-1). The validation experiment showed that ANFIS-GA method can be a promising tool for selecting the optimal conditions for maximum paclitaxel biosynthesis, as a case study.


Assuntos
Técnicas de Cultura de Células/métodos , Corylus/química , Paclitaxel/biossíntese , Algoritmos , Corylus/metabolismo , Fungos/química , Fungos/metabolismo , Modelos Lineares , Células Vegetais/química , Células Vegetais/metabolismo , beta-Ciclodextrinas/química
12.
PLoS Genet ; 16(8): e1008996, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32841242

RESUMO

The utilization of different carbon sources in filamentous fungi underlies a complex regulatory network governed by signaling events of different protein kinase pathways, including the high osmolarity glycerol (HOG) and protein kinase A (PKA) pathways. This work unraveled cross-talk events between these pathways in governing the utilization of preferred (glucose) and non-preferred (xylan, xylose) carbon sources in the reference fungus Aspergillus nidulans. An initial screening of a library of 103 non-essential protein kinase (NPK) deletion strains identified several mitogen-activated protein kinases (MAPKs) to be important for carbon catabolite repression (CCR). We selected the MAPKs Ste7, MpkB, and PbsA for further characterization and show that they are pivotal for HOG pathway activation, PKA activity, CCR via regulation of CreA cellular localization and protein accumulation, as well as for hydrolytic enzyme secretion. Protein-protein interaction studies show that Ste7, MpkB, and PbsA are part of the same protein complex that regulates CreA cellular localization in the presence of xylan and that this complex dissociates upon the addition of glucose, thus allowing CCR to proceed. Glycogen synthase kinase (GSK) A was also identified as part of this protein complex and shown to potentially phosphorylate two serine residues of the HOG MAPKK PbsA. This work shows that carbon source utilization is subject to cross-talk regulation by protein kinases of different signaling pathways. Furthermore, this study provides a model where the correct integration of PKA, HOG, and GSK signaling events are required for the utilization of different carbon sources.


Assuntos
Proteínas Quinases Dependentes de AMP Cíclico/genética , Glucose/metabolismo , Quinases da Glicogênio Sintase/genética , Proteínas Quinases Ativadas por Mitógeno/genética , Aspergillus nidulans/enzimologia , Repressão Catabólica/genética , Fungos/genética , Fungos/metabolismo , Glicerol/metabolismo , Concentração Osmolar , Fosforilação/genética , Mapas de Interação de Proteínas/genética , Proteínas Repressoras/genética , Xilose/metabolismo
13.
Proc Natl Acad Sci U S A ; 117(34): 20932-20942, 2020 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-32778594

RESUMO

Many pathogenic fungi exploit stomata as invasion routes, causing destructive diseases of major cereal crops. Intensive interaction is expected to occur between guard cells and fungi. In the present study, we took advantage of well-conserved molecules derived from the fungal cell wall, chitin oligosaccharide (CTOS), and chitosan oligosaccharide (CSOS) to study how guard cells respond to fungal invasion. In Arabidopsis, CTOS induced stomatal closure through a signaling mediated by its receptor CERK1, Ca2+, and a major S-type anion channel, SLAC1. CSOS, which is converted from CTOS by chitin deacetylases from invading fungi, did not induce stomatal closure, suggesting that this conversion is a fungal strategy to evade stomatal closure. At higher concentrations, CSOS but not CTOS induced guard cell death in a manner dependent on Ca2+ but not CERK1. These results suggest that stomatal immunity against fungal invasion comprises not only CTOS-induced stomatal closure but also CSOS-induced guard cell death.


Assuntos
Quitina/metabolismo , Estômatos de Plantas/imunologia , Estômatos de Plantas/metabolismo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/fisiologia , Cálcio/metabolismo , Morte Celular/efeitos dos fármacos , Quitina/fisiologia , Quitosana/metabolismo , Fungos/metabolismo , Proteínas Quinases/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Serina-Treonina Quinases/fisiologia , Transdução de Sinais/efeitos dos fármacos
14.
Toxicon ; 186: 141-150, 2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-32795459

RESUMO

The aim of this study is to determine the best aflatoxin B1 degradation conditions which was optimized using a combination of the Plackett-Burman and Box-Behnken methods with Panus neostrigosus culture filtrate. Panus neostrigosus was grown in a modified Kirk Broth medium to determine optimal degradation conditions. As a result, aflatoxin B1 was degraded under varying culture conditions. The Plackett-Burman method was designed after sixteen different experiments with fifteen variables. The three most effective variables (Sucrose, yeast extract, wheat bran) were chosen for the Box-Behnken methodology. The aflatoxin B1 degradation rate was 49% in just 1 h exposure to culture filtrate which was obtained under optimal growth conditions; (g-ml/L) sucrose 10, yeast extract 3, wheat bran 3, soytone 5, KH2PO4 2, MgSO4.7H2O 0.5, CaCl2.H2O 0.1, ammonium tartrate 2, trace element solution 10; 28 °C of incubation temperature, medium pH 5, 7.5% inoculum rate, 125 rpm of agitation speed, and a twelve-day incubation period. The SDS-PAGE studies show that the enzyme responsible for AFB1 degradation has 38 kDa molecular weight and has no laccase or MnP activity. To the best of our knowledge, this is the first report for AFB1 degradation by Panus neostrigosus.


Assuntos
Aflatoxina B1/metabolismo , Fungos/metabolismo , Biodegradação Ambiental , Temperatura
15.
Arch Microbiol ; 202(10): 2779-2789, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32743668

RESUMO

Endophytes are considered one of the most important microbial resources for obtaining biomolecules of therapeutic use. Passiflora incarnata, widely employed by the pharmaceutical industry, shows therapeutic effects on anxiety, nervousness, constipation, dyspepsia and insomnia based on their antioxidant compounds. In this study, from 315 endophytic fungi isolated from P. incarnata leaves, 60 were selected to determinate presence of chemical constituents related with antioxidant activity, based on their production of soluble pigments. The promising fungi were evaluated specifically on their potential to produce phenolic compounds, flavonoids and for antioxidant activity. Five isolates significantly produced flavonoids and phenolic compounds in the ethyl acetate and n-Butanol extracts, also saponins and high antioxidant activity against the DPPH (2.2-diphenyl-1-picrylhydrazyl) free radical. A strain of Aspergillus nidulans var. dentatus (former Emericella dentata) was able to produce tannins as well; its butanolic extract was very similar than the BHT (butylated hydroxytoluene) (94.3% × 94.32%) and Rutin (95.8%) reference substances in the DPPH radical scavenging. Similarly, a Chaetomium strain exhibited 93.6% and 94.7% of antioxidant activity in their ethyl acetate and butanolic fractions, respectively. The chromatographic analysis of the ethyl acetate fraction from the Aspergillus strain revealed the production of orcinol (3.19%). Four-methoxymethylphenol (4.79%), sorbicillin (33.59%) and ergosterol (23.08%) was produced by Trichoderma longibrachiatum and isopropenyl-1,4-dimethyl-1,2,3,3a,4,5,6,7-octahydroazulene were found in two Fusarium oxysporum strains. The phytochemical screening showed that all analyzed fungi were able to produce a kind of secondary metabolite (phenols, flavonoids, tannins and/or saponins). The study shows a great underexplored potential for industrial application of P. incarnata endophytes.


Assuntos
Antioxidantes/análise , Flavonoides/análise , Fungos/isolamento & purificação , Fungos/metabolismo , Passiflora/microbiologia , Fenóis/análise , Compostos de Bifenilo/análise , Endófitos/classificação , Endófitos/isolamento & purificação , Endófitos/metabolismo , Radicais Livres/análise , Fungos/classificação , Extratos Vegetais/química , Folhas de Planta/microbiologia , Taninos
16.
Nat Commun ; 11(1): 3684, 2020 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-32703952

RESUMO

Empirical evidence for the response of soil carbon cycling to the combined effects of warming, drought and diversity loss is scarce. Microbial carbon use efficiency (CUE) plays a central role in regulating the flow of carbon through soil, yet how biotic and abiotic factors interact to drive it remains unclear. Here, we combine distinct community inocula (a biotic factor) with different temperature and moisture conditions (abiotic factors) to manipulate microbial diversity and community structure within a model soil. While community composition and diversity are the strongest predictors of CUE, abiotic factors modulated the relationship between diversity and CUE, with CUE being positively correlated with bacterial diversity only under high moisture. Altogether these results indicate that the diversity × ecosystem-function relationship can be impaired under non-favorable conditions in soils, and that to understand changes in soil C cycling we need to account for the multiple facets of global changes.


Assuntos
Biomassa , Ciclo do Carbono , Microbiota/fisiologia , Microbiologia do Solo , Solo/química , Bactérias/metabolismo , Fungos/metabolismo
17.
Food Chem ; 332: 127417, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32629332

RESUMO

The use of UHPH sterilization in the absence of SO2 has been used to eliminate wild microorganisms and inactivate oxidative enzymes. A white must of the Muscat of Alexandria grape variety was continuously processed by UHPH at 300 MPa (inlet temperature: 23-25 °C). The initial microbial load of the settled must was 4-log CFU/mL for both yeast and moulds, and slightly lower for bacteria. After UHPH processing, no microorganisms were detected in 1 mL. UHPH musts remain without fermentative activity for more than 60 days. Concentrations of the thermal markers indicated the absence of thermal damage in the UHPH-treated musts, since 5-hydroxymethylfurfural was not detected. In addition, the must treated by UHPH keeps terpene concentrations similar to those of the untreated controls. A strong inactivation of the oxidative enzymes was observed, with no browning at room temperature for more than 3 days. The antioxidant value of the UHPH-treated must was 156% higher than the control.


Assuntos
Bactérias/crescimento & desenvolvimento , Microbiologia de Alimentos/métodos , Fungos/crescimento & desenvolvimento , Esterilização/métodos , Vinho/análise , Bactérias/enzimologia , Bactérias/metabolismo , Fermentação , Manipulação de Alimentos , Fungos/enzimologia , Fungos/genética , Fungos/metabolismo , Humanos , Dióxido de Enxofre/análise , Paladar , Temperatura , Vitis/química
18.
PLoS One ; 15(6): e0234870, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32569317

RESUMO

Mucoromycota fungi possess a versatile metabolism and can utilize various substrates for production of industrially important products, such as lipids, chitin/chitosan, polyphosphates, pigments, alcohols and organic acids. However, as far as commercialisation is concerned, establishing industrial biotechnological processes based on Mucoromycota fungi is still challenging due to the high production costs compared to the final product value. Therefore, the development of co-production concept is highly desired since more than one valuable product could be produced at the time and the process has a potentially higher viability. To develop such biotechnological strategy, we applied a high throughput approach consisting of micro-titre cultivation and FTIR spectroscopy. This approach allows single-step biochemical fingerprinting of either fungal biomass or growth media without tedious extraction of metabolites. The influence of two types of nitrogen sources and different levels of inorganic phosphorus on the co-production of lipids, chitin/chitosan and polyphosphates for nine different oleaginous Mucoromycota fungi was evaluated. FTIR analysis of biochemical composition of Mucoromycota fungi and biomass yield showed that variation in inorganic phosphorus had higher effect when inorganic nitrogen source-ammonium sulphate-was used. It was observed that: (1) Umbelopsis vinacea reached almost double biomass yield compared to other strains when yeast extract was used as nitrogen source while phosphorus limitation had little effect on the biomass yield; (2) Mucor circinelloides, Rhizopus stolonifer, Amylomyces rouxii, Absidia glauca and Lichtheimia corymbifera overproduced chitin/chitosan under the low pH caused by the limitation of inorganic phosphorus; (3) Mucor circinelloides, Amylomyces rouxii, Rhizopus stolonifer and Absidia glauca were able to store polyphosphates in addition to lipids when high concentration of inorganic phosphorus was used; (4) the biomass and lipid yield of high-value lipid producers Mortierella alpina and Mortierella hyalina were significantly increased when high concentrations of inorganic phosphorus were combined with ammonium sulphate, while the same amount of inorganic phosphorus combined with yeast extract showed negative impact on the growth and lipid accumulation. FTIR spectroscopy revealed the co-production potential of several oleaginous Mucoromycota fungi forming lipids, chitin/chitosan and polyphosphates in a single cultivation process.


Assuntos
Biotecnologia/métodos , Técnicas de Cultura de Células/métodos , Quitina/biossíntese , Fungos , Lipídeos/biossíntese , Polifosfatos/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Meios de Cultura , Fungos/crescimento & desenvolvimento , Fungos/metabolismo , Nitrogênio/metabolismo , Fósforo/metabolismo
19.
Arch Microbiol ; 202(8): 2033-2058, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32506150

RESUMO

Polyaromatic hydrocarbons (PAHs) are considered as hazardous organic priority pollutants. PAHs have immense public concern and critical environmental challenge around the globe due to their toxic, carcinogenic, and mutagenic properties, and their ubiquitous distribution, recalcitrance as well as persistence in environment. The knowledge about harmful effects of PAHs on ecosystem along with human health has resulted in an interest of researchers on degradation of these compounds. Whereas physico-chemical treatment of PAHs is cost and energy prohibitive, bioremediation i.e. degradation of PAHs using microbes is becoming an efficient and sustainable approach. Broad range of microbes including bacteria, fungi, and algae have been found to have capability to use PAHs as carbon and energy source under both aerobic and anaerobic conditions resulting in their transformation/degradation. Microbial genetic makeup containing genes encoding catabolic enzymes is responsible for PAH-degradation mechanism. The degradation capacity of microbes may be induced by exposing them to higher PAH-concentration, resulting in genetic adaptation or changes responsible for high efficiency towards removal/degradation. In last few decades, mechanism of PAH-biodegradation, catabolic gene system encoding catabolic enzymes, and genetic adaptation and regulation have been investigated in detail. This review is an attempt to overview current knowledge of microbial degradation mechanism of PAHs, its genetic regulation with application of genetic engineering to construct genetically engineered microorganisms, specific catabolic enzyme activity, and application of bioremediation for reclamation of PAH-contaminated sites. In addition, advanced molecular techniques i.e. genomic, proteomic, and metabolomic techniques are also discussed as powerful tools for elucidation of PAH-biodegradation/biotransformation mechanism in an environmental matrix.


Assuntos
Bactérias , Biodegradação Ambiental , Microbiologia Ambiental , Poluentes Ambientais/metabolismo , Fungos , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Bactérias/genética , Bactérias/metabolismo , Biotransformação , Fungos/genética , Fungos/metabolismo , Engenharia Genética , Genoma Bacteriano/genética , Genoma Fúngico/genética
20.
Food Chem ; 330: 127252, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32585587

RESUMO

Mycoprotein is a food ingredient from filamentous fungi rich in protein and fibre. This study investigated the protein bioaccessibility from the fungal cells by colourimetric assays in different mycoprotein formulations, following extraction methods and in vitro gastrointestinal digestion. The methods effects were further analysed by static laser light scattering, SDS-PAGE and optical-fluorescence microscopy. The extraction methods released a comparable proportion of protein (30 wt%) independent of sample concentration (10 wt% and 25 wt%), whereas the simulated digestions endpoints released a higher proportion of protein from the less concentrated (46 wt%). Furthermore, mechanical/physical processing had only a minor impact. Intestinal proteases promoted the most efficient protein release but without causing any apparent damage to the cell walls when viewed by microscopy. This suggested that the enzymes can diffuse through the cell walls, due to its porosity/permeability, and are the main factors responsible for the hydrolysis and bioaccessibility of protein from mycoprotein.


Assuntos
Proteínas Fúngicas/metabolismo , Animais , Disponibilidade Biológica , Parede Celular/química , Parede Celular/metabolismo , Fibras na Dieta/metabolismo , Digestão , Proteínas Fúngicas/química , Fungos/química , Fungos/metabolismo
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