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1.
Int J Food Microbiol ; 322: 108585, 2020 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-32179333

RESUMO

A total of 20 dried date samples, chosen as representative among those available on the Perugia (Umbria, Central Italy) market, were analyzed for the possible occurrence of fungal species and related contamination by fungal secondary metabolites. Twenty-six isolates, representative of the total mycobiota, were obtained and morphologically identified as belonging to the genera Aspergillus, Penicillium and Cladosporium. Inside each genus, molecular characterization (by partial sequencing of ITS region and/or ß-tubulin and calmodulin regions for Aspergillus and Penicillium isolates or actin region for Cladosporium isolates) and in vitro mycotoxigenic profile characterization (by LC-MS/MS analysis) showed the presence of the following species: A. flavus, A. tubingensis, P. brevicompactum, P. chrysogenum, P. crustosum, P. glabrum, P. solitum, P. venetum, C. cladosporioides, C. limoniforme and C. halotolerans, with A. tubingensis as the prevalent species and P. crustosum, P. solitum, P. venetum and C. limoniforme first reported here on dates. Date packaging and format showed an effect on the incidence of isolated fungi, with the lowest incidence recovered from whole dates and in hermetic bag packaging. These findings can be useful both for dried dates producers and consumers, guiding them towards choices of packaging and format with a lower risk of mycotoxigenic species presence. However, no fungal metabolites were detected in the dried date samples analyzed, which were therefore regarded as safe for human consumption, underlining the absence of correspondence between fungal isolation and mycotoxin contaminations.


Assuntos
Microbiologia de Alimentos , Alimentos em Conserva/microbiologia , Fungos/isolamento & purificação , Phoeniceae/microbiologia , Aspergillus/classificação , Aspergillus/genética , Aspergillus/isolamento & purificação , Aspergillus/metabolismo , Cladosporium/classificação , Cladosporium/genética , Cladosporium/isolamento & purificação , Cladosporium/metabolismo , Embalagem de Alimentos/métodos , Frutas/microbiologia , Fungos/classificação , Fungos/genética , Fungos/metabolismo , Humanos , Itália , Micotoxinas/análise , Penicillium/classificação , Penicillium/genética , Penicillium/isolamento & purificação , Penicillium/metabolismo
2.
Int J Food Microbiol ; 317: 108498, 2020 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-31918247

RESUMO

Aspergillus carbonarius consistently produces large amounts of ochratoxin A (OTA), a mycotoxin with nephrotoxic effects on animals and humans. In the present study, we analyzed the transcriptional changes associated to OTA production in three atypical non-ochratoxigenic strains of A. carbonarius. In addition, in vitro interactions between ochratoxigenic strains of A. carbonarius and A. niger and non-ochratoxigenic strains of A. carbonarius and A. tubingensis were studied in order to evaluate their potential for controlling OTA production. RNA-seq analysis revealed that there are 696 differentially expressed genes identified in the three non-OTA-producing strains, including 280 up-regulated and 333 down-regulated genes. A functional and gene ontology enrichment analysis revealed that the processes related to metabolic and oxidation processes, associated with functions such as oxidoreductase and hydrolase activity were down regulated. All the genes related with OTA biosynthesis in A. carbonarius were the most down-regulated genes in non-ochratoxigenic strains. We also showed that these strains possess a deleterious mutation in the AcOTApks gene required for OTA biosynthesis. Moreover, one of these strains gave the best control of OTA production resulting in an OTA reduction of 98-100% in co-inoculation with an ochratoxigenic strain of A. niger and an OTA reduction of 79-89% with an ochratoxigenic strain of A. carbonarius. Results of this study provided novel insights into the knowledge of the OTA biosynthetic pathway in these non-ochratoxigenic wild strains, and showed the biocontrol potential of these strains.


Assuntos
Aspergillus/genética , Aspergillus/metabolismo , Agentes de Controle Biológico/metabolismo , Interações Microbianas/fisiologia , Aspergillus/classificação , Perfilação da Expressão Gênica , Humanos , Hidrolases/metabolismo , Ocratoxinas/biossíntese , Oxirredutases/metabolismo , Vitis/microbiologia
3.
Food Chem ; 311: 125984, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31855773

RESUMO

Aflatoxin M1 (AFM1) in milk and milk products has been recognised as an issue for over 30 years. Controlling AFM1 in milk is important to protect human health and trade. Preventing contamination by avoiding fungal contamination of cattle feed is the best method of control, however this is hard to avoid in some countries. Treating milk containing AFM1 is an alternative control measure, however, there is no single approved method. The challenge is to select a treatment method that is effective but does not affect the organoleptic quality of milk. This study reviews the strategies for degrading AFM1 in milk including yeast, lactic acid bacteria, enzyme, peroxide, ozone, UV light and cold plasma. This review compares the efficacy, influencing factors, (possible) mechanisms of activity, advantages, limitations and potential future trends of these methods and provides some recommendations for the treatment of milk to reduce the risk of AFM1 contamination.


Assuntos
Aflatoxina M1/química , Contaminação de Alimentos/análise , Leite/química , Aflatoxina M1/metabolismo , Animais , Aspergillus/metabolismo , Lactobacillus/metabolismo , Ozônio/química , Gases em Plasma/química , Saccharomyces cerevisiae/metabolismo , Raios Ultravioleta
4.
Int J Food Microbiol ; 313: 108376, 2020 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-31731141

RESUMO

Maize is an important staple crop for the majority of the population in Uganda. However, in tropical and subtropical climates, maize is frequently contaminated with aflatoxins, a group of cancer-causing and immuno-suppressive mycotoxins produced by Aspergillus section Flavi fungi. In Uganda, there is limited knowledge about the causal agents of aflatoxin contamination. The current study determined both the aflatoxin levels in pre-harvest maize across Uganda and the structures of communities of aflatoxin-producing fungi associated with the maize. A total of 256 pre-harvest maize samples were collected from 23 major maize-growing districts in eight agro-ecological zones (AEZ). Maize aflatoxin content ranged from 0 to 3760 ng/g although only around 5% for Ugandan thresholds. For EU it is about 16% of the samples contained aflatoxin concentrations above tolerance thresholds. A total of 3105 Aspergillus section Flavi isolates were recovered and these were dominated by the A. flavus L morphotype (89.4%). Densities of aflatoxin-producing fungi were negatively correlated with elevation. Farming systems and climatic conditions of the AEZ are thought to have influenced communities' structure composition. Fungi from different AEZ varied significantly in aflatoxin-producing abilities and several atoxigenic genotypes were identified. The extremely high aflatoxin concentrations detected in some of the studied regions indicate that management strategies should be urgently designed for use at the pre-harvest stage. Atoxigenic genotypes detected across Uganda could serve as aflatoxin biocontrol agents to reduce crop contamination from fields conditions and throughout the maize value chain.


Assuntos
Aflatoxinas/análise , Aspergillus/metabolismo , Contaminação de Alimentos/análise , Zea mays/microbiologia , Agricultura , Aspergillus/genética , Aspergillus/isolamento & purificação , Ecologia , Uganda , Zea mays/química , Zea mays/crescimento & desenvolvimento
5.
Chemosphere ; 239: 124698, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31493753

RESUMO

Synthetic silver nanoparticles (AgNPs) are being extensively used in our daily lives; however, they may also pose a risk to public health and environment. Nowadays, biological AgNPs are considered an excellent alternative, since their synthesis occurs by a green technology of low cost and easy scaling. However, studies with these biological nanomaterials (NM) are still limited. Thus, a more careful assessment of their industrial application, economic feasibility and ecotoxicological impacts is crucial. The aim of this study was to investigate the effects of different concentrations of mangrove fungus Aspergillus tubingensis AgNPs on the aerobic heterotrophs soil microorganisms, rice seeds (Oryza sativa) and zebrafish (Danio rerio). Biogenic AgNPs were less harmful for soil microbiota compared to AgNO3. On rice seeds, the AgNPs displayed a dose-dependent inhibitory effect on germination and their subsequent growth and development. The percentage of inhibition of rice seed germination was 30, 69 and 80% for 0.01, 0.1 and 0.5 mM AgNPs, respectively. After 24 h of AgNPs exposition at a limit concentration of 0.2 mM, it did not induce mortality of the zebrafish D. rerio. Overall, A. tubingensis AgNPs can be considered as a suitable alternative to synthetic nanoparticles.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Nanopartículas Metálicas/química , Prata/farmacologia , Solo/química , Animais , Aspergillus/metabolismo , Germinação/efeitos dos fármacos , Oryza/efeitos dos fármacos , Oryza/crescimento & desenvolvimento , Oryza/fisiologia , Sementes/efeitos dos fármacos , Peixe-Zebra/crescimento & desenvolvimento
6.
Biosci Biotechnol Biochem ; 84(1): 198-207, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31566090

RESUMO

High glycosidase-producing strains of Aspergillus luchuensis were isolated from 2-deoxyglucose (2-DG) resistant mutants. α-Amylase, exo-α-1,4-glucosidase, ß-glucosidase and ß-xylosidase activity in the mutants was ~3, ~2, ~4 and ~2.5 times higher than the parental strain RIB2604 on koji-making conditions, respectively. Citric acid production and mycelia growth of the mutants, however, approximately halved to that of the parent. Compared to the parent, the alcohol yield from rice and sweet potato shochu mash of the mutant increased ~5.7% and 3.0%, respectively. The mutant strains showed significantly low glucose assimilability despite the fructose one was almost normal, and they had a single missense or nonsense mutation in the glucokinase gene glkA. The recombinant strain that was introduced at one of the mutations, glkA Q300K, demonstrated similar but not identical phenotypes to the mutant strain. This result indicates that glkA Q300K is one of the major mutations in 2-DG resistant strains.


Assuntos
Aspergillus/genética , Aspergillus/isolamento & purificação , Separação Celular/métodos , Códon sem Sentido/genética , Genes Fúngicos/genética , alfa-Glucosidases/metabolismo , Aspergillus/classificação , Aspergillus/metabolismo , Catepsina A/metabolismo , Ácido Cítrico/metabolismo , Desoxiglucose/farmacologia , Farmacorresistência Fúngica , Etanol/metabolismo , Fermentação , Alimentos e Bebidas Fermentados/microbiologia , Frutose/metabolismo , Glucoquinase/genética , Glucose/metabolismo , Ipomoea batatas/química , Oryza/química , Fenótipo , Saccharomyces cerevisiae/classificação , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/isolamento & purificação , Saccharomyces cerevisiae/metabolismo , Xilosidases/metabolismo , alfa-Amilases/metabolismo , beta-Glucosidase/metabolismo
7.
Ecotoxicol Environ Saf ; 188: 109756, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31711776

RESUMO

Soil co-contaminated with heavy metals and organics is often difficult to remediate. In this study, pot experiments were conducted to investigate the concurrent removal of cadmium (Cd, two levels: CdL [10 mg kg-1] and CdH [50 mg kg-1]) and trichlorfon (TCF, 100 mg kg-1) from co-contaminated soil by comparing the following remediation methods: natural remediation (NR), soil inoculated with Aspergillus sydowii (AS), soil planted with Brassica juncea (BJ), and soil planted with B. juncea and inoculated with A. sydowii (BJ-AS). The physiological responses of B. juncea and soil enzyme activities after remediation were also studied. B. juncea grew well in co-contaminated soil at both Cd levels. The biomass and chlorophyll content of B. juncea in CdH soil were lower than those in CdL soil, whereas the malondialdehyde content and activities of catalase, peroxidase and superoxide dismutase of B. juncea in CdH soil were higher than those in CdL soil. Cd accumulation in B. juncea was high in CdH soil, whereas high Cd removal efficiency was observed in CdL soil. TCF could be thoroughly degraded within 35 days in NR at both Cd-level soils. AS, BJ and BJ-AS promoted TCF degradation and enhanced the activities of catalase, urease, sucrase and alkaline phosphatase in soil compared with the NR. BJ-AS showed the highest phytoextraction ratio (3.32% in CdL and 1.34% in CdH soil) and TCF degradation rate (half-life of 2.18 and 2.37 days in CdL and CdH soil, respectively). These results demonstrate that BJ-AS could effectively remove Cd and TCF from soil and is thus a feasible technology for the bioremediation of these co-contaminated soil.


Assuntos
Aspergillus/crescimento & desenvolvimento , Cádmio/análise , Mostardeira/crescimento & desenvolvimento , Poluentes do Solo/análise , Solo/química , Triclorfon/análise , Aspergillus/metabolismo , Biodegradação Ambiental , Biomassa , Cádmio/metabolismo , Catalase/metabolismo , Malondialdeído/metabolismo , Mostardeira/metabolismo , Microbiologia do Solo , Poluentes do Solo/metabolismo , Triclorfon/metabolismo
8.
Pak J Pharm Sci ; 32(4): 1679-1686, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31608890

RESUMO

Four fungal isolates were identified in this study of which three were Aspergillus species with Aspergillus flavus having the highest frequency followed by A. parasiticus. The result of high frequency of Aspergillus flavus and Aspergillus parasiticus in the Zea mays sample revealed production of aflatoxins. Maize sample in Awka was found to contain aflatoxin B1 (9.60ppb) and B2 (13.3ppb). Inhibition of A. flavus and A. parasiticus with Azadirachta indica and Garcinia kola seed extracts showed that the test plant extracts were effective for reducing mycelial growth on the test organism. Methanolic extract of G. kola showed antifungal inhibitory activity on the test organisms and the highest at 10% concentration. With ethanol extracts of G. kola, the antifungal activity was effective i.e. for inhibition of A. flavus and A. parasiticus, with A. parasiticus having the higher percentage inhibition at 10%. Inhibiting growth of Aspergillus flavus and Aspergillus parasiticus using methanolic and ethanolic extracts of neem seeds was effective in the inhibition of the test organism at 10%. The methanolic and ethanolic extracts of combined Garcinia kola and neem seeds revealed effective inhibition of A. flavus and A. parasiticus with ethanolic extracts of the combined test plants exerting the highest inhibition against A. flavus (80.43±3.62). The extracts from this plant show the ability to suppress growth of toxigenic A. flavus and A. parasiticus. Phytochemical analysis showed that the methanolic and ethanolic extracts of G. kola and neem seeds showed the presence of secondary metabolites and this may be a reason for the inhibitory activity on A. flavus and A. parasiticus. Results from this study will be important in planning a management strategy against aflatoxin-producing fungi and other fungi associated with spoilage of stored food products.


Assuntos
Aflatoxinas/metabolismo , Antifúngicos/farmacologia , Aspergillus/metabolismo , Azadirachta/química , Garcinia kola/química , Zea mays/microbiologia , Aflatoxinas/análise , Antifúngicos/química , Aspergillus/efeitos dos fármacos , Aspergillus/isolamento & purificação , Aspergillus/patogenicidade , Etanol/química , Microbiologia de Alimentos , Armazenamento de Alimentos , Metanol/química , Testes de Sensibilidade Microbiana , Nigéria , Compostos Fitoquímicos/análise , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Sementes/microbiologia
9.
Mar Drugs ; 17(10)2019 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-31614563

RESUMO

Four new compounds were isolated from the Vietnamese marine sediment-derived fungus Aspergillus flocculosus, one aspyrone-related polyketide aspilactonol G (2), one meroterpenoid 12-epi-aspertetranone D (4), two drimane derivatives (7,9), together with five known metabolites (1,3,5,6,8,10). The structures of compounds 1-10 were established by NMR and MS techniques. The absolute stereoconfigurations of compounds 1 and 2 were determined by a modified Mosher's method. The absolute configurations of compounds 4 and 7 were established by a combination of analysis of ROESY data and coupling constants as well as biogenetic considerations. Compounds 7 and 8 exhibited cytotoxic activity toward human prostate cancer 22Rv1, human breast cancer MCF-7, and murine neuroblastoma Neuro-2a cells.


Assuntos
Antineoplásicos/farmacologia , Organismos Aquáticos/metabolismo , Aspergillus/metabolismo , Produtos Biológicos/farmacologia , Fungos/metabolismo , Animais , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Sedimentos Geológicos/microbiologia , Humanos , Células MCF-7 , Espectroscopia de Ressonância Magnética/métodos , Biologia Marinha/métodos , Camundongos , Policetídeos/farmacologia , Sesquiterpenos/farmacologia
10.
Environ Monit Assess ; 191(10): 622, 2019 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-31494726

RESUMO

Bioleaching of heavy metals from industrial contaminated soil using metallotolerant fungi is the most efficient, cost-effective, and eco-friendly technique. In the current study, the contaminated soil samples from Hattar Industrial Estate revealed a total lead (Pb) and mercury (Hg) concentration of 170.90 mg L-1 and 26.66 mg L-1, respectively. Indigenous metallotolerant fungal strains including Aspergillus niger M1, Aspergillus fumigatus M3, Aspergillus terreus M6, and Aspergillus flavus M7 were isolated and identified by pheno- and genotyping. A. fumigatus and A. flavus of soil sample S1 showed higher efficiency for Pb removal (99.20% and 99.30%, respectively), in SDB medium. Likewise, A. niger and A. terreus of soil sample S2 showed higher efficiency for Hg removal (96% and 95.50%, respectively), in YPG medium. Furthermore, the maximum uptake efficiency for Pb removal (8.52 mg g-1) from soil sample S1 was noticed for A. fumigatus in YPG medium, while the highest uptake efficiency (4.23 mg g-1) of A. flavus M2 strain was observed with CYE medium. Similarly, the maximum uptake efficiency of 0.41 mg g-1 and 0.44 mg g-1 for Hg removal from soil sample S2 was found for A. niger and A. terreus strains, respectively, in CYE medium. Thus, in order to address the major issue of industrial waste pollution, indigenous fungal strains A. fumigatus (M1) and A. terreus (M7), isolated in this study, could be used (ex situ or in situ) to remediate soils contaminated with Pb and Hg.


Assuntos
Aspergillus/metabolismo , Chumbo/metabolismo , Mercúrio/metabolismo , Metais Pesados/metabolismo , Poluentes do Solo/metabolismo , Solo/química , Aspergillus/classificação , Aspergillus/genética , Monitoramento Ambiental , Recuperação e Remediação Ambiental , Genótipo , Resíduos Industriais , Chumbo/análise , Mercúrio/análise , Metais Pesados/análise , Fenótipo , Poluentes do Solo/análise
11.
BMC Complement Altern Med ; 19(1): 241, 2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31488109

RESUMO

BACKGROUND: Mulberry silkworm larvae (Bombyx mori) are known as the oldest resource of food and traditional medicine. Although silkworm larvae have been reported to treat various chronic diseases, the effect of fermentation by microorganisms improving the biological activities of silkworm larvae was not reported. In the present study, fermented silkworm larvae was developed via solid-state fermentation with Aspergillus kawachii and investigated its anti-cancer activity in human hepatocellular carcinoma cells. METHODS: We investigated the anti-cancer effects of unfermented (SEE) and fermented silkworm larva ethanol extract (FSEE) on HepG2 human hepatocellular carcinoma cells as well as compared changes in free amino acid, fatty acid, and mineral contents. Anti-cancer activities were evaluated by SRB staining, cell cycle analysis, Annexin V staining, Hoechst staining, DNA fragmentation analysis and western blot analysis. Fatty acid, free amino acid and mineral contents of SEE and FSEE were determined by gas chromatography, amino acid analyzer and flame atomic absorption spectrophotometer, respectively. RESULTS: Compared with SEE, treatment with FSEE resulted in apoptotic cell death in HepG2 cells characterized by G0/G1 phase cell cycle arrest, DNA fragmentation, and formation of apoptotic bodies. Furthermore, FSEE significantly up-regulated pro-apoptotic as well as down-regulated anti-apoptotic proteins in HepG2 cells. However, an equivalent concentration of SEE did not induce cell cycle arrest or apoptosis in HepG2 cells. Moreover, fermentation process by Aspergillus kawachii resulted in enhancement of fatty acid contents in silkworm larvae, whereas amino acid and mineral contents were decreased. CONCLUSION: Collectively, this study demonstrates that silkworm larvae solid state-fermented by Aspergillus kawachii strongly potentiates caspase-dependent and -independent apoptosis pathways in human hepatocellular carcinoma cells by regulating secondary metabolites.


Assuntos
Antineoplásicos/farmacologia , Aspergillus/metabolismo , Bombyx/microbiologia , Carcinoma Hepatocelular/tratamento farmacológico , Larva/química , Neoplasias Hepáticas/tratamento farmacológico , Animais , Antineoplásicos/química , Antineoplásicos/metabolismo , Apoptose/efeitos dos fármacos , Bombyx/química , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/fisiopatologia , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Fragmentação do DNA , Fermentação , Células Hep G2 , Humanos , Larva/microbiologia , Neoplasias Hepáticas/fisiopatologia
12.
Artigo em Inglês | MEDLINE | ID: mdl-31535946

RESUMO

Infestation of food crops by fungi has led to serious economic losses in the international market. There is a paucity of information on the multi-mycotoxin profile of cashew nuts from different geographical locations in Nigeria and South Africa. This work aims at comparing the fungal metabolite profile of cashew nut from two African countries using HPLC-FLD and LC-MS/MS. The differences in distribution of the fungal metabolites across the two countries were also examined. A total of 75 (39; Nigeria, 36; South Africa) roasted cashew nuts were purchased from 14 different locations in Nigeria and 10 major supermarkets in South Africa. The samples were subjected to HPLC analysis for aflatoxin and zearalenone and LC-MS/MS analysis for multiple metabolite profiling. Total aflatoxins (0.03-0.77 µg/kg and 0.01-0.28 µg/kg) and zearalenone (123.2 and 788.6 µg/kg) were quantified in nut samples from South Africa and Nigeria, respectively. In contrast, LC-MS/MS analysis showed that none of the major fungi metabolites except for one (citrinin) was present in detectable amount in Nigerian cashew nuts (31.3 µg/kg). Other microbial metabolites present in the nuts were; Aspergillus metabolites (< LOD to 398 × 104 µg/kg and < LOD to 1760 µg/kg); flavoglaucin (5.4-177.4 µg/kg and 45.5-18,368 µg/kg), 7-hydroxykaurenolide (5.5-45.8 µg/kg and 3.5-33.7 µg/kg), chloramphenicol (0.3-4.5 µg/kg) for South African and Nigerian cashew nuts, respectively. The incidence rate of the fusarium toxins beauvericin and bikaverin were higher in Nigerian cashew nut (100% and 17%) than the South African nuts (8% and 8%), 7-Hydroxykaurenolide and chloramphenicol were found in all the cashew nut samples. A total of 15 unspecific metabolites (17-100%) were recorded in the nuts from both countries. Information on the metabolite profile of cashew nuts will provide useful information for policy makers, border agencies and other health-related Institutes.


Assuntos
Anacardium/química , Aspergillus/química , Aspergillus/metabolismo , Contaminação de Alimentos/análise , Micotoxinas/análise , Anacardium/metabolismo , Nigéria , África do Sul
13.
J Agric Food Chem ; 67(38): 10660-10666, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31479263

RESUMO

Two new indolyl diketopiperazines, gartryprostatins A and B (1 and 2), with an unusual 2,3-furan-fused pyrano[2,3-g]pyrrolo[1″,2″:4',5']pyrazino[1',2':1,5]pyrrolo[2,3-b]indole nucleus, along with a new naturally occurring compound (gartryprostatin C, 3) were isolated from the solid culture of Aspergillus sp. GZWMJZ-258, an endophyte from Garcinia multiflora (Guttiferae). The structures of compounds 1-3 were determined by nuclear magnetic resonance, mass spectrometry, Marfey's analysis of amino acids, and chemical calculation. Compounds 1-3 displayed selective inhibition on human FLT3-ITD mutant AML cell line, MV4-11, with IC50 values of 7.2, 10.0, and 0.22 µM, respectively.


Assuntos
Aspergillus/química , Dicetopiperazinas/farmacologia , Endófitos/química , Garcinia/microbiologia , Plantas Medicinais/microbiologia , Aspergillus/genética , Aspergillus/isolamento & purificação , Aspergillus/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Dicetopiperazinas/química , Dicetopiperazinas/metabolismo , Endófitos/genética , Endófitos/isolamento & purificação , Endófitos/metabolismo , Humanos , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Estrutura Molecular
14.
Int J Food Microbiol ; 306: 108273, 2019 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-31382055

RESUMO

Ochratoxin A (OTA) is a nephrotoxic mycotoxin naturally found in a wide range of food commodities throughout the world. Aspergillus carbonarius is the most important source of OTA in food commodities such as wine, grapes and dried vine fruits and is also responsible for the formation of OTA in coffee. The aim of this study was to determine the simultaneous effect of three culture media (Czapek Yeast Extract Broth (CYB); Synthetic Grape Juice Medium (SGM) and White grape juice (WGJ)) at three water activity (aw) levels (0.90; 0.95 and 0.98-0.99), and three incubation temperatures (15 °C, 25 °C and 35 °C) on the growth and OTA production by 16 strains of A. carbonarius. The strains were mainly isolated from grapes from areas with a Mediterranean climate. All the strains were confirmed for identity by sequencing of the calmodulin gene. The assay was performed in microtiter plates, determining the absorbance at 530 nm and the concentration of OTA after 1, 2, 4 and 10 days of incubation. No significant differences were observed in absorbance values between the strains. The highest absorbance values were recorded in CYB at 0.99 aw and at 0.95 aw after 10 days of incubation at 25 °C and 35 °C. None of the strains were able to grow at 0.90 aw and 15 °C in any culture media after 10 days of incubation. OTA concentration was statistically higher at 15 °C than at 25 °C or 35 °C. The highest significant OTA values were obtained at 0.98-0.99 aw and the best culture media for OTA production was CYB, followed by WGJ and SGM. While strains isolated from Mediterranean climate foods had a similar behavior despite being isolated from different geographical areas, OTA concentration produced by one Robusta coffee strain from Thailand was statistically higher at 25 °C than at 15 °C. This would suggest that the type of food matrices and consequently the adaptation of A. carbonarius strains to different climatic conditions would have a greater influence on the ecophysiology of the strains than only their geographical origin.


Assuntos
Aspergillus/crescimento & desenvolvimento , Aspergillus/metabolismo , Meios de Cultura/farmacologia , Micotoxinas/biossíntese , Ocratoxinas/biossíntese , Aspergillus/patogenicidade , Clima , Meio Ambiente , Microbiologia de Alimentos , Temperatura , Tailândia , Vitis/microbiologia , Água/análise , Vinho/microbiologia
15.
Plant Physiol Biochem ; 142: 342-350, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31382176

RESUMO

Aspergillus aculeatus has been shown to stimulate plant growth, but its role in plants abiotic stress tolerance and the underlying mechanisms are not fully documented. In this study, we investigated the mechanisms of A.aculeatus-mediated drought, heat and salt stress tolerance in tall fescue. The results showed that A.aculeatus inoculation improved drought and heat stress tolerance in tall fescue as observed from its effect on turf quality (TQ) and leaf relative water content (LWC). In the same stress conditions, A.aculeatus alleviated reactive oxygen species (ROS) induced burst and cell damage, as indicated by lower H2O2, electrolyte leakage (EL) and malondialdehyde (MDA) levels. Additionally, the A.aculeatus inoculated plants exhibited higher photosynthetic efficiency than uninoculated plants under drought, heat and salt stress conditions. The fungus reduced the uptake of Na+, and inoculated plants showed lower Na+/K+, Na+/Ca2+and Na+/Mg2+ ratios compared to uninoculated ones under salt stress. Furthermore, comparative metabolomic analysis showed that A.aculeatus exclusively increased amino acid (such as proline and glycine) and sugar (such as glucose, fructose, sorbose, and talose) accumulation under drought and heat stress. However, there were no differences between inoculated and uninoculated plants except for changes in H2O2 level, Na+ in the root and photosynthetic efficiency under salt stress. Taken together, this study provides the first evidence of the protective roles of A.aculeatus in the tall fescue response to abiotic stresses, partially via protection of photosynthesis and modulation of metabolic homeostasis.


Assuntos
Aspergillus/metabolismo , Festuca/microbiologia , Aspergillus/crescimento & desenvolvimento , Aspergillus/fisiologia , Clorofila/metabolismo , Desidratação , Festuca/metabolismo , Festuca/fisiologia , Resposta ao Choque Térmico , Homeostase , Peróxido de Hidrogênio/metabolismo , Malondialdeído/metabolismo , Metabolômica , Fotossíntese , Folhas de Planta/metabolismo , Folhas de Planta/fisiologia , Estresse Salino , Equilíbrio Hidroeletrolítico
16.
Ecotoxicol Environ Saf ; 183: 109484, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31398583

RESUMO

This work evaluated the degradation of the Acid Blue 161 and Procion Red MX-5B dyes in a binary solution by the filamentous fungus Aspergillus terreus and the yeast Saccharomyces cerevisiae in systems with and without electrochemical oxidation as the pretreatment process. UV-Vis spectrophotometry, high-performance liquid chromatography with (HPLC), Fourier transform infrared (FT-IR) spectroscopy and Salmonella/microsome assay (Ames test) were applied towards the degradation analysis of the dyes. Adsorption tests with white clay immobilized on alginate were also conducted after the discoloration treatments to remove intermediate metabolites formed during the degradation of the dye molecules. The discoloration treatments led to the complete color removal of the solutions in all the systems tested. The clay demonstrated affinity for the metabolites formed after discoloration treatments, the removal rates were variable, but the all systems has proved efficient. The Salmonella/microsome assay (Ames test) with strains TA98 and TA100 in the absence and presence of exogenous metabolism (S9 microsomal system, Moltox) revealed that the initial molecules and by-products of the metabolism of the dyes were direct mutagens. The electrochemical/A. terreus/clay system was able to discolor the solutions and transform the direct mutagens into non-mutagenic compounds in addition to reducing the mutagenic potency of the pro-mutagens to the Salmonella strain TA100/S9, which demonstrates the high efficiency of this system with regard to discoloring and degrading azo dye molecules and their by-products. Therefore, this study showed that although not having standard treatment system for this type of pollutant, the combination of treatments can be considered promising. The use of electrochemical oxidation along with microbiological treatment may lead to the degradation and mineralization of these compounds, reducing or eliminating the environmental impact caused by the improper disposal of these dyes in aquatic environments.


Assuntos
Compostos Azo/metabolismo , Compostos Azo/toxicidade , Corantes/metabolismo , Corantes/toxicidade , Mutagênicos/metabolismo , Mutagênicos/toxicidade , Aspergillus/metabolismo , Cromatografia Líquida de Alta Pressão , Complexos de Coordenação/metabolismo , Complexos de Coordenação/toxicidade , Naftalenossulfonatos/metabolismo , Naftalenossulfonatos/toxicidade , Oxirredução , Estresse Oxidativo , Saccharomyces cerevisiae/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier
17.
Int J Food Microbiol ; 308: 108303, 2019 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-31437694

RESUMO

Environmental conditions during ripening of dry-cured meat products favour growth of fungal population on their surface. Some of these moulds can produce mycotoxins. Paprika is one of the ingredients usually used in the formulation of raw-cured sausages, and its addition could influence the growth and production of mycotoxins of the moulds present in these products. In this work the effect of Spanish smoked paprika "Pimentón de la Vera" on growth of Aspergillus parasiticus and Penicillium nordicum and production of aflatoxins B1 (AFB1), G1 (AFG1) and ochratoxin A (OTA) respectively, was evaluated. Moulds were grown in a culture medium made from lyophilized fresh pork meat added with 4% salt and different concentrations of Spanish smoked paprika (1, 2 and 3%) at several water activity values (0.98, 0.94 and 0.87) and temperature (20-25 °C), to simulate conditions usually found during ripening of dry-cured meat products. Mould growth was evaluated by measuring the diameter of the colony every 24 h, and the production of mycotoxins by UHPLC-MS/MS every 2 days, during 10 days of incubation. Addition of paprika favours growth of the two mould species tested. However, the synthesis of mycotoxins was reduced at 0.94 and 0.98 aw when at least a 2% of paprika was added. Therefore, the addition of Spanish smoked paprika at 2-3% in the formulations may help to minimize AFs and OTA production in dry-cured meat products such as loins or "chorizo" sausages.


Assuntos
Aflatoxina B1/biossíntese , Aspergillus/crescimento & desenvolvimento , Capsicum/química , Produtos da Carne/microbiologia , Ocratoxinas/biossíntese , Penicillium/crescimento & desenvolvimento , Animais , Aspergillus/metabolismo , Microbiologia de Alimentos , Penicillium/metabolismo , Fumaça , Cloreto de Sódio/análise , Suínos , Espectrometria de Massas em Tandem , Temperatura , Água
18.
Int J Food Microbiol ; 306: 108265, 2019 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-31325815

RESUMO

The use of yeast-derived volatile organic compounds (VOCs) represents a promising strategy for the biological control of various plant pathogens, including mycotoxin-producing fungi. Previous studies demonstrated the efficacy of the low-fermenting yeast Candida intermedia isolate 253 in reducing growth, sporulation, and ochratoxin A biosynthesis by Aspergillus carbonarius MPVA566. This study aimed to investigate whether the inhibitory effect of the yeast volatilome is solely attributable to 2-phenylethanol, its major component, or if a synergistic effect of all volatilome components is required to achieve an effective control of the fungal growth and metabolism. Microbiological methods, HPLC measurements and a UPLC-MS/MS approach were used to investigate the metabolic profile of A. carbonarius MPVA566 at different growing conditions: standard incubation (control), exposed to C. intermedia 253 volatilome, and incubation in the presence of 2-phenylethanol. Both yeast volatilome and 2-phenylethanol succeeded in the macroscopic inhibition of the radial mycelial growth, along with a significant reduction of ochratoxin A production. Functional classification of the fungal proteome identified in the diverse growing conditions revealed a different impact of both yeast VOCs and 2-phenylethanol exposure on the fungal proteome. Yeast VOCs target an array of metabolic routes of fungal system biology, including a marked reduction in protein biosynthesis, proliferative activity, mitochondrial metabolism, and particularly in detoxification of toxic substances. Exposure to 2-phenylethanol only partially mimicked the metabolic effects observed by the whole yeast volatilome, with protein biosynthesis and proliferative activity being reduced when compared with the control samples, but still far from the VOCs-exposed condition. This study represents the first investigation on the effects of yeast-derived volatilome and 2-phenylethanol on the metabolism of a mycotoxigenic fungus by means of proteomics analysis. CHEMICAL COMPOUNDS STUDIED OR USED IN THIS ARTICLE: 2-Phenylethanol (PubChem CID: 6054); ochratoxin-A (PubChem CID: 442530); sodium dodecyl sulfate (PubChem CID: 3423265); dithiothreitol (PubChem CID: 446094); phenylmethylsulfonyl fluoride (PubChem CID: 4784); iodoacetamide (PubChem CID: 3727); ammonium bicarbonate (PubChem CID: 14013); acetic acid (PubChem CID: 176); and acetonitrile (PubChem CID: 6342).


Assuntos
Aspergillus/crescimento & desenvolvimento , Aspergillus/metabolismo , Álcool Feniletílico/metabolismo , Compostos Orgânicos Voláteis/metabolismo , Aspergillus/genética , Candida/metabolismo , Cromatografia Líquida , Fermentação , Micotoxinas/metabolismo , Ocratoxinas/metabolismo , Proteoma , Proteômica , Espectrometria de Massas em Tandem
19.
World J Microbiol Biotechnol ; 35(7): 109, 2019 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-31280382

RESUMO

Echinocandin B (ECB) is an important lipohexapeptide used for chemical manufacture of the antifungal agent anidulafungin. Sterigmatocystin (ST) is a polyketide mycotoxin produced by certain species of Aspergillus such as Aspergillus delacroxii SIPIW15, which could produce both ECB and ST. However, the presence of the potent carcinogen ST will greatly affect the quality and safety of ECB production. Therefore, it is essential to eliminate the ST biosynthesis and increase ECB titers in Asp. delacroxii SIPIW15. In this study, the polyketide synthase gene (stcA) required for biosynthesis of ST and its flanking region in Asp. delacroxii SIPIW15 were cloned, sequenced and analyzed firstly. Based on Agrobacterium-mediated transformation, the ΔstcA mutant AMT-1 was obtained and its yield of ECB was increased by 40% without ST detected at the same time as compared to the original strain. The results of the fed-batch experiments showed that the ECB yield of the ΔstcA strain AMT-1 was increased to 2163 ± 31 mg/l and no ST was detected in the 50 l bioreactor. This work suggested that the ΔstcA strain AMT-1 has the potential for application in ECB production improvement, and more importantly, to eliminate ST-related environmental pollution in ECB fermentation industry.


Assuntos
Aspergillus/genética , Aspergillus/metabolismo , Equinocandinas/biossíntese , Equinocandinas/genética , Proteínas Fúngicas/biossíntese , Proteínas Fúngicas/genética , Genes Fúngicos/genética , Policetídeo Sintases/genética , Esterigmatocistina/biossíntese , Agrobacterium/genética , Anidulafungina , Antifúngicos , Sequência de Bases , Técnicas de Cultura Celular por Lotes , Reatores Biológicos , DNA Fúngico/isolamento & purificação , Fermentação , Engenharia Metabólica , Redes e Vias Metabólicas/genética , Metabolismo Secundário/genética , Transformação Genética
20.
Environ Sci Pollut Res Int ; 26(26): 26844-26854, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31300993

RESUMO

Co-contamination with heavy metals and pesticides is a severe environmental problem, but little information is available regarding the simultaneous removal of these pollutants. In this study, we showed that Aspergillus sydowii strain PA F-2 isolated from soil contaminated with heavy metal and pesticides can simultaneously degrade trichlorfon (TCF) and adsorb Cd(II) from mineral salt medium. The maximum removal rates for TCF and Cd(II) were 55.52% and 57.90%, respectively, in the treatment containing 100 mg L-1 TCF and 2 mg L-1 Cd(II). As the initial Cd(II) concentration increased (2, 5, and 10 mg L-1), the PA F-2 biomass, TCF degradation rate, and Cd(II) adsorption efficiency decreased, whereas the Cd(II) adsorption capacity by PA F-2 increased. The addition of exogenous glucose and sucrose significantly increased the PA F-2 biomass as well as the removal of TCF and Cd(II). Moreover, the TCF degradation pathway and Cd(II) adsorption mechanism were investigated by gas chromatography-mass spectrometry, scanning electron microscopy, and Fourier transform infrared spectroscopy. These results suggest that PA F-2 has potential applications in the bioremediation of TCF and Cd(II) co-contamination.


Assuntos
Aspergillus/metabolismo , Cádmio/metabolismo , Triclorfon/metabolismo , Adsorção , Aspergillus/isolamento & purificação , Biodegradação Ambiental , Cádmio/isolamento & purificação , Cromatografia Gasosa-Espectrometria de Massas , Glucose/metabolismo , Microscopia Eletrônica de Varredura , Microbiologia do Solo , Poluentes do Solo/isolamento & purificação , Poluentes do Solo/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Poluentes Químicos da Água/metabolismo
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