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1.
Sci Rep ; 14(1): 6076, 2024 03 13.
Artículo en Inglés | MEDLINE | ID: mdl-38480751

RESUMEN

When onions are improperly stored, a post-harvest disease known as black mold of onion bulbs can result in considerable economic losses. Aspergillus section Nigri, one of many species, has been implicated in the development of black mold. In the present study, rot onion bulbs were collected from markets in Qena, Egypt. Thirteen Aspergillus section Nigri isolates were obtained and identified by morphological and molecular characterization. The ochratoxins potential of isolated A. section Nigri was tested, and three isolates were producers at the range of 1.5-15 ppm. For the presence of pks gene, no amplification product was detected. Using the fungal growth inhibition test, the isolates of A. niger were inhibited by eco-friendly materials Cement and Zeolite. Cement exhibited maximum percentage growth inhibition against the tested isolates at 74.7-86.7%. The pathogenicity activity of the A. niger isolates was tested by inoculation of healthy onion bulbs, other onion bulbs covered with Cement and Zeolite before inoculation by A. niger was used. The two treatments significantly reduced bulbs rot disease of onion than untreated bulbs. Seven and nine isolates showed 0% rot on covered bulbs by Cement and Zeolite, respectively as compared with inoculated onions, which exhibited rot ranging from 55 to 80%. Using eco-friendly materials with efficiency against post-harvest bulbs rot of onion was evaluated in this study.


Asunto(s)
Ocratoxinas , Zeolitas , Cebollas/microbiología , Aspergillus/genética , Egipto
2.
World J Microbiol Biotechnol ; 39(11): 295, 2023 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-37658165

RESUMEN

Aspergillus is a well-studied fungal genus that is widely used in the processing of plant biomass in industries. This study investigated the effects of space exposure on the ability of Aspergillus costaricaensis, a filamentous fungus isolated from rotten orange peel, to degrade pectin. These fungal spores were carried into space by the Long March 5B carrier rocket and exposed to cosmic radiation for 79 h. After the flight, these spores were resuscitated, and then the growing strains were screened with pectin as the sole carbon source, and the pectinase activity was evaluated. A mutant with increased biomass accumulation ability and pectin-degrading activity compared to the ground control strain was obtained. Comparative transcriptome analysis revealed that several CAZymes genes were significantly upregulated in the mutant, especially those related to pectin degradation. Among the 44 pectinases identified from the annotated genome, 42 were up-regulated. The activities of these pectinases are able to synergistically break down the structure of pectin. In addition, the expression of some genes involved in metabolism, sugar transport, and stress response was altered. These results imply that space exposure might serve as a potential mutagenesis breeding technique, offering the opportunity to acquire biomass-degrading microbial strains with potential for industrial application.


Asunto(s)
Pectinas , Fitomejoramiento , Aspergillus/genética , Biomasa , Poligalacturonasa/genética
3.
J Agric Food Chem ; 71(21): 8023-8037, 2023 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-37203140

RESUMEN

The intracellular polysaccharides of Aspergillus cristatus (IPSs) from Fuzhuan brick tea have been demonstrated to improve immune function linked to modulating the gut microbiota. Herein, to further investigate the efficacy of IPSs to maintain gut homeostasis, the protection of the purified fraction of IPSs (IPSs-2) on the mice with colitis induced by dextran sulfate sodium (DSS) and the underlying mechanisms were explored in this study. The results revealed that IPSs-2 alleviated the typical symptoms of colitis and suppressed the excessive inflammatory mediators, regulating the genes related to inflammatory responses in the colon at the mRNA level. Meanwhile, IPSs-2 treatment reinforced the intestinal barrier function by ameliorating the DSS-induced histological injury, facilitating the differentiation of goblet cells to enhance Mucin-2 generation, and enhancing the expression of tight junction proteins to alleviate colitis. In addition, IPSs protected against colitis by promoting the production of short-chain fatty acids (SCFAs), the activation of SCFAs receptors, and the leverage of the gut microbiota via the enrichment of Bacteroides, Parabacteroides, Faecalibacterium, Flavonifractor_plautii, and Butyricicoccus, linking with reducing inflammation and repairing intestinal barrier function. Overall, our research revealed the therapeutic potential of IPSs-2 as a prebiotic for attenuating inflammatory bowel disease and provided a rationale for future investigation.


Asunto(s)
Colitis , Microbioma Gastrointestinal , Animales , Ratones , Colitis/inducido químicamente , Colitis/tratamiento farmacológico , Colitis/genética , Aspergillus/genética , Colon , , Sulfato de Dextran/efectos adversos , Ratones Endogámicos C57BL , Modelos Animales de Enfermedad
4.
Food Res Int ; 162(Pt A): 111981, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36461293

RESUMEN

Aspergillus fungi are extensively used in traditional food fermentation, so their functions, mechanisms, and safety risks are worth exploring. In this study, a dominant fungal strain (P1) was isolated from a fermented pu-erh tea and identified as A. luchuensis by phylogenetic analysis of fungal internally-transcribed spacer sequencing, partial ß-tubulin and calmodulin genes. A pure-strain fermentation of tea leaves was developed, and tea compounds were analyzed by widely-targeted metabolomics, using high-performance liquid chromatography (HPLC) and liquid chromatography mass spectrometry (LC-MS). The mycotoxins, aflatoxin (B1, B2, M1 and M2), fumonisin B1 and B2, ochratoxin A, citrinin, were not detected in fermented tea leaves using methods in the National Standard of the Peoples' Republic of China. The genome of 36.60 Mb with 11,836 protein-coding genes was sequenced by PacBio sequencing and annotated. Expression of fungal genes during fermentation was analyzed by Illumina HiSeq 2500; genes encoding enzymes including glycoside hydrolases, phenolic acid esterases, laccases, tyrosinases, dehydrogenases, peroxidases, dioxygenases, monooxygenases, decarboxylases and O-methyltransferases were identified. These enzymes catalyze hydrolysis, oxidation, ring cleavage, hydroxylation, decarboxylation and O-methylation of phenolic compounds , significantly (p < 0.05) changing the phenolic compound composition. While, phenolic compounds were degraded through degradation of aromatic compounds pathways and xenobiotics biodegradation and metabolism pathways. These findings advance knowledge of the functions and mechanisms of action of Aspergillus in traditional food fermentation.


Asunto(s)
Aspergillus , Fenoles , Fermentación , Filogenia , Aspergillus/genética , Monofenol Monooxigenasa ,
5.
J Appl Microbiol ; 132(1): 483-494, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34153147

RESUMEN

AIM: Potassium (K) is a key determinant for plant development and productivity. However, more than 90% of K in the soil exists in an insoluble form. K-solubilizing microbes play an important role in the transformation of insoluble K. Thus, the objective of this study was to evaluate K-dissolving ability of Aspergillus aculeatus (F) and growth-promoting properties in perennial ryegrass. METHODS AND RESULTS: Perennial ryegrass inoculated with A. aculeatus exhibited enhanced soluble K accompanied with higher growth rate and turf quality, compared with the noninoculated regimen. In addition, A. aculeatus also played a primary role in increasing chlorophyll content and photosynthetic capacity of the plant exposed to LK+F (K-feldspar plus A. aculeatus) treatment, compared with the CK (control, no K-feldspar and A. aculeatus), F (only A. aculeatus) and LK (only K-feldspar) groups. Furthermore, the antioxidase activities (CAT and POD) were significantly increased while the oxidative damage (EL and MDA) was dramatically decreased in the LK+F group compared to the LK (K-feldspar) group. Finally, in perennial ryegrass leaves, the genes expression levels of HAK8, HAK12 and HKT18 were obviously elevated in the LK+F group, compared to the CK, F and LK groups. CONCLUSION: We concluded that A. aculeatus could solubilize K from bound form and be considered as K-solubilizing biofertilizer through supplementing K in soil. SIGNIFICANCE AND IMPACT OF THE STUDY: Aspergillusaculeatus has the potential to be used as a biofertilizer in sustainable agriculture.


Asunto(s)
Lolium , Aspergillus/genética , Fotosíntesis , Potasio
6.
Biotechnol Prog ; 38(1): e3206, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34460147

RESUMEN

The application of biological nanoparticles (NPs) can be considered as a way to overcome the problem of antifungal resistance in pathogenic fungi. This study takes a new approach to biosynthesized NPs influence on the expression of CYP51A and HSP90 antifungal resistance genes in Aspergillus fumigatus and A. flavus, and comparison with antifungal agents. Selenium NPs (Se-NPs) were biosynthesized using Aspergillus strains and their production was proved by several methods including, UV-Vis, XRD, FTIR, FESEM, and EDX techniques. The minimum inhibitory concentrations (MICs) of Aspergillus strains were determined using the CLSI M38-A2 broth microdilution method. The differences in expression levels of CYP51A and HSP90 genes were examined between untreated and treated of A. fumigatus and A. flavus using itraconazole and amphotericin B and biosynthesized Se-NPs through real-time PCR. After confirming the results of NPs synthesis, the MIC of itraconazole and amphotericin B against A. fumigatus and A. flavus was 4 µg/ml. Based on the real-time PCR results, the obtained ∆∆CTs for these strains were -0.18, -1.46, and -1.14. Whereas the MIC values for treated samples with Se-NPs have decreased to 0.5 µg/ml, and the ∆∆CTs for these were -0.25, -1.76, and -1.68. The expression of CYP51A and HSP90 genes was significantly down-regulated through the use of Se-NPs against A. fumigatus and A. flavus.


Asunto(s)
Nanopartículas , Selenio , Anfotericina B/farmacología , Antifúngicos/farmacología , Aspergillus/genética , Aspergillus flavus , Aspergillus fumigatus/genética , Itraconazol/farmacología , Pruebas de Sensibilidad Microbiana , Selenio/farmacología , Triazoles/farmacología , Voriconazol/farmacología
7.
Braz J Microbiol ; 52(4): 1791-1805, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34339015

RESUMEN

Endophytes are regarded with immense potentials in terms of plant growth promoting (PGP) elicitors and mimicking secondary metabolites of medicinal importance. Here in the present study, we explored Bacopa monnieri plants to isolate, identify fungal endophytes with PGP elicitation potentials, and investigate secretion of secondary metabolites such as bacoside and withanolide content under in vitro conditions. Three fungal endophytes isolated (out of 40 saponin producing isolates) from leaves of B. monnieri were examined for in vitro biosynthesis of bacosides. On morphological, biochemical, and molecular identification (ITS gene sequencing), the isolated strains SUBL33, SUBL51, and SUBL206 were identified as Nigrospora oryzae (MH071153), Alternaria alternata (MH071155), and Aspergillus terreus (MH071154) respectively. Among these strains, SUBL33 produced highest quantity of Bacoside A3 (4093 µg mL-1), Jujubogenin isomer of Bacopasaponin C (65,339 µg mL-1), and Bacopasaponin C (1325 µg mL-1) while Bacopaside II (13,030 µg mL-1) was produced by SUBL51 maximally. Moreover, these aforementioned strains also produced detectable concentration of withanolides-Withaferrin A, Withanolide A (480 µg mL-1), and Withanolide B (1024 µg mL-1) respectively. However, Withanolide A was not detected in the secondary metabolites of strain SUBL51. To best of our knowledge, the present study is first reports of Nigrospora oryzae as an endophyte in B. monnieri with potentials of biosynthesis of economically important phytomolecules under in vitro conditions.


Asunto(s)
Bacopa , Endófitos , Hongos , Saponinas , Witanólidos , Alternaria/genética , Alternaria/aislamiento & purificación , Alternaria/metabolismo , Ascomicetos/genética , Ascomicetos/aislamiento & purificación , Ascomicetos/metabolismo , Aspergillus/genética , Aspergillus/aislamiento & purificación , Aspergillus/metabolismo , Bacopa/microbiología , Endófitos/genética , Endófitos/aislamiento & purificación , Endófitos/metabolismo , Hongos/genética , Hongos/aislamiento & purificación , Hongos/metabolismo , Hojas de la Planta/microbiología , Saponinas/biosíntesis , Witanólidos/metabolismo
8.
Sci Rep ; 11(1): 9347, 2021 04 30.
Artículo en Inglés | MEDLINE | ID: mdl-33931710

RESUMEN

A deep-sea fungus Aspergillus sydowii BOBA1 isolated from marine sediment at a depth of 3000 m was capable of degrading spent engine (SE) oil. The response of immobilized fungi towards degradation at elevated pressure was studied in customized high pressure reactors without any deviation in simulating in situ deep-sea conditions. The growth rate of A. sydowii BOBA1 in 0.1 MPa was significantly different from the growth at 10 MPa pressure. The degradation percentage reached 71.2 and 82.5% at atmospheric and high pressure conditions, respectively, within a retention period of 21 days. The complete genome sequence of BOBA1 consists of 38,795,664 bp in size, comprises 2582 scaffolds with predicted total coding genes of 18,932. A total of 16,247 genes were assigned with known functions and many families found to have a potential role in PAHs and xenobiotic compound metabolism. Functional genes controlling the pathways of hydrocarbon and xenobiotics compound degrading enzymes such as dioxygenase, decarboxylase, hydrolase, reductase and peroxidase were identified. The spectroscopic and genomic analysis revealed the presence of combined catechol, gentisate and phthalic acid degradation pathway. These results of degradation and genomic studies evidenced that this deep-sea fungus could be employed to develop an eco-friendly mycoremediation technology to combat the oil polluted marine environment. This study expands our knowledge on piezophilic fungi and offer insight into possibilities about the fate of SE oil in deep-sea.


Asunto(s)
Aspergillus/genética , Aspergillus/metabolismo , Biodegradación Ambiental , Genoma Fúngico , Sedimentos Geológicos/microbiología , Peroxidasas/metabolismo , Petróleo/metabolismo , Aspergillus/crecimiento & desarrollo , Petróleo/microbiología , Hidrocarburos Policíclicos Aromáticos/metabolismo
9.
Curr Microbiol ; 78(2): 590-603, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33392668

RESUMEN

Sinai's important geographical and strategic position is attracting researchers to explore opportunities to maximize exploitation of its treasures, especially in the area of sustainable development. One of the fields of exploitation is extracting valuable metals from low-grade ores using green technologies. In this study, we examined the possibility of microbial leaching of uranium (U) from a rock sample collected from Wadi Naseib, Sinai, Egypt. Twenty previously isolated and tentatively identified native microorganisms, 10 Streptomyces and 10 Aspergillus, were used to make U-bioleaching using cells (direct) and cell metabolites (indirect). The tested isolates showed variable U-bioleaching efficiencies and the highest results was attained via the indirect method (57.2 ± 9.2% and 83.6 ± 2.3%) using two isolates that were identified genotypically as Streptomyces sp. EGY1 and Aspergillus niveus EGY2 respectively. TEM images showed that cells of A. niveus EGY2 made biomineralization, biosorption and bioaccumulation of U. The present study revealed that neither high acid production nor high phosphatase activities guarantees a high U-bioleaching efficiency. Many factors affecting the process were also studied using A. niveus EGY2. The highest U-bioleaching efficiency (87.8 ± 8.7%) was attained using pH 9, 160 rpm of both culturing and bioleaching steps, rock particle size of above 700 µm and 1% pulp density. U was recovered from leach liquor after optimization experiments using NaOH and its concentration was 64.35%. Our study revealed that Aspergillus niveus EGY2 could be promising in future scaling-up studies and pilot trials using the tested rock sample.


Asunto(s)
Streptomyces , Uranio , Aspergillus/genética , Egipto , Streptomyces/genética
10.
Int Microbiol ; 24(2): 169-181, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33389217

RESUMEN

L-Glutaminase is an amidohydrolase which can act as a vital chemotherapeutic agent against various malignancies. In the present work, L-glutaminase productivity from Aspergillus versicolor Faesay4 was significantly increased by 7.72-fold (from 12.33 ± 0.47 to 95.15 ± 0.89 U/mL) by optimizing submerged fermentation parameters in Czapek's Dox (CZD) medium including an incubation period from 3 (12.33 ± 0.47 U/mL) to 6 days (23.36 ± 0.58 U/mL), an incubation temperature from 30 °C (23.36 ± 0.49 U/mL) to 25 °C (31.08 ± 0.60 U/mL), initial pH from pH 5.0 (8.49 ± 0.21 U/mL)  to pH 7.0 (32.18 ± 0.57 U/mL), replacement of glucose (30.19 ± 0.52 U/mL) by sucrose (48.97 ± 0.67 U/mL) as the carbon source at a concentration of 2.0% (w/v), increasing glutamine concentration as the nitrogen source from 1.0% (w/v, 48.54 ± 0.48 U/mL) to 1.5% (w/v, 63.01 ± 0.60 U/mL), and addition of a mixture of KH2PO4 and NaCl (0.5% w/v for both) to SZD as the metal supplementation (95.15 ± 0.89 U/mL). Faesay4 L-glutaminase was purified to yield total activity 13,160 ± 22.76 (U), specific activity 398.79 ± 9.81 (U/mg of protein), and purification fold 2.1 ± 3.18 with final enzyme recovery 57.22 ± 2.17%. The pure enzyme showed a molecular weight of 61.80 kDa, and it was stable and retained 100.0% of its activity at a temperature ranged from 10 to 40 °C and pH 7.0. In our trials, to increase the enzyme activity by optimizing the assay conditions (which were temperature 60 °C, pH 7.0, substrate glutamine, substrate concentration 1.0%, and reaction time 60 min), the enzyme activity increased by 358.8% after changing the assay temperature from 60 to 30 °C and then increased by 138% after decreasing the reaction time from 60 to 40 min. However, both pH 7.0 and glutamine as the substrate remain the best assay parameters for the L-glutaminase activity. When the glutamine in the assay as the reaction substrate was replaced by asparagine, lysine, proline, methionine, cysteine, glycine, valine, phenylalanine, L-alanine, aspartic acid, tyrosine, and serine, the enzyme lost 23.86%, 29.0%, 31.0%, 48.3%, 50.0%, 73.6%, 74.51%, 80.42%, 82.5%, 83.43%, 88.36%, and 89.78% of its activity with glutamine, respectively. Furthermore, Mn2+, K+, Na+, and Fe3+ were enzymatic activators that increased the L-glutaminase activity by 25.0%, 18.05%, 10.97%, and 8.0%, respectively. Faesay4 L-glutaminase was characterized as a serine protease enzyme as a result of complete inhibition by all serine protease inhibitors (PMSF, benzamidine, and TLCK). Purified L-glutaminase isolated from Aspergillus versicolor Faesay4 showed potent DPPH scavenging activities with IC50 = 50 µg/mL and anticancer activities against human liver (HepG-2), colon (HCT-116), breast (MCF-7), lung (A-549), and cervical (Hela) cancer cell lines with IC50 39.61, 12.8, 6.18, 11.48, and 7.25 µg/mL, respectively.


Asunto(s)
Antineoplásicos/química , Antineoplásicos/aislamiento & purificación , Antioxidantes/aislamiento & purificación , Aspergillus/enzimología , Proteínas Fúngicas/química , Proteínas Fúngicas/aislamiento & purificación , Glutaminasa/química , Glutaminasa/aislamiento & purificación , Antineoplásicos/farmacología , Antioxidantes/química , Antioxidantes/farmacología , Aspergillus/química , Aspergillus/genética , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Estabilidad de Enzimas , Proteínas Fúngicas/farmacología , Glutaminasa/farmacología , Humanos , Concentración de Iones de Hidrógeno , Cinética , Peso Molecular , Especificidad por Sustrato
11.
Int J Food Microbiol ; 337: 108958, 2021 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-33176225

RESUMEN

The occurrence of black aspergilli in onions has been reported as frequent, and this group of fungi harbors potentially toxigenic species. In addition, Aspergillus niger has been reported as the causative agent of black mold rot, an important postharvest disease that causes damage throughout the world. Brazil stands out as one of the world's largest onion producers. However, few studies have been conducted to investigate the mycobiota in Brazilian onions. For this reason, we investigated the mycobiota of 48 market (n = 25) and field (n = 23) onion bulb samples. Nineteen soil samples were collected from the same fields and evaluated. In field onions and soil samples, Penicillium spp. was the prevalent fungal group, whereas in market samples A. section Nigri was the most frequent group. Due to the taxonomic complexity of this group, species identification was supported by phylogenetic data (CaM gene). A. welwitschiae was the most prevalent species in market samples. Black aspergillus strains were evaluated for fumonisin B2 (FB2) and ochratoxin A (OTA) production. Overall, 53% and 2.2% of the strains produced FB2 and OTA, respectively. The occurrence of FB2 and OTA was also investigated in onion bulb samples but none showed contamination with these mycotoxins.


Asunto(s)
Aspergillus/aislamiento & purificación , Microbiología de Alimentos , Cebollas/microbiología , Microbiología del Suelo , Aspergillus/clasificación , Aspergillus/genética , Aspergillus/metabolismo , Brasil , Humanos , Micobioma/genética , Micotoxinas/análisis , Micotoxinas/metabolismo , Cebollas/química , Penicillium/clasificación , Penicillium/genética , Penicillium/aislamiento & purificación , Filogenia
12.
Molecules ; 25(19)2020 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-32987627

RESUMEN

The aim of this project was to improve the Aspergillus terreus strain and pretreatment of sugarcane bagasse as carrier substrate for bulk production of lovastatin, a cholesterol-lowering drug, in solid state fermentation. Sugarcane bagasse was treated with alkali (1-3% NaOH) for the conversion of complex polysaccharides into simple sugars for better utilization of carrier substrate by microorganism for maximum lovastatin production. Ethidium bromide (time of exposure 30-180 min) was used to induce mutation in Aspergillus terreus and the best mutant was selected on the basis of inhibition zone appeared on petri plates. Fermented lovastatin was quantified by high-performance liquid chromatography. The fermented lovastatin, produced by parent and mutant Aspergillus terreus strain, was checked on body weight, blood glucose and serum cholesterol, ALT, AST, HDL-C, LDL-C, TG and TC levels of rats for their cholesterol lowering capacity. Our results indicate that selected strain along with 2% NaOH treated sugar cane bagasse was best suitable for bulk production of lovastatin by fermentation and fermented lovastatin effectively lower the cholesterol level of rats.


Asunto(s)
Anticolesterolemiantes , Aspergillus , Colesterol/sangre , Lovastatina , Animales , Anticolesterolemiantes/aislamiento & purificación , Anticolesterolemiantes/farmacocinética , Anticolesterolemiantes/farmacología , Aspergillus/genética , Aspergillus/crecimiento & desarrollo , Celulosa/química , Evaluación Preclínica de Medicamentos , Lovastatina/biosíntesis , Lovastatina/aislamiento & purificación , Lovastatina/farmacocinética , Lovastatina/farmacología , Masculino , Ratas , Saccharum/química
13.
Carbohydr Polym ; 248: 116752, 2020 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-32919555

RESUMEN

Rhamnogalaturonans I (RGI) pectins, which are a major component of the plant primary cell wall, can be recalcitrant to digestion by commercial enzymatic cocktails, in particular during fruit juice clarification process. To overcome these problems and get better insights into RGI degradation, three RGI degrading enzymes (RHG: Endo-rhamnogalacturonase; ABF: α-Arabinofuranosidases; GAN: Endo-ß-1,4-galactanase) from Aspergillus aculeatinus were expressed in Pichia pastoris, purified and fully biochemically characterized. All three enzymes showed acidic pH optimum, and temperature optima between 40-50 °C. The Km values were 0.5 mg.ml-1, 1.64 mg.ml-1 and 3.72 mg.ml-1 for RHG, ABF, GAN, respectively. NMR analysis confirmed an endo-acting mode of action for RHG and GAN, and exo-acting mode for ABF. The application potential of these enzymes was assessed by measuring changes in viscosity of RGI-rich camelina mucilage, showing that RHG-GAN enzymes induced a decrease in viscosity by altering the structures of the RGI backbone and sidechains.


Asunto(s)
Aspergillus/enzimología , Proteínas Fúngicas/metabolismo , Pectinas/metabolismo , Aspergillus/genética , Aspergillus/metabolismo , Pared Celular/química , Estabilidad de Enzimas , Proteínas Fúngicas/genética , Glicósido Hidrolasas/genética , Glicósido Hidrolasas/metabolismo , Concentración de Iones de Hidrógeno , Cinética , Espectroscopía de Resonancia Magnética , Pichia/genética , Polisacárido Liasas/genética , Polisacárido Liasas/metabolismo , Proteínas Recombinantes/metabolismo , Temperatura
14.
Int J Food Microbiol ; 333: 108795, 2020 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-32721627

RESUMEN

In recent times green tea (GT) consumption has increased, due to the numerous studies that indicate a wide variety of health benefits following its regular consumption. The aim of this study was to assess the bioburden (bacteria and fungi) of bulk and bags of GT marketed in Lisbon and to obtain a more refined fungal burden characterization, including azole resistance profile. The bacteriota in tea bags before boiling ranged from lower than the detection limit to 1770 CFU.g-1, whereas in brew samples ranged from lower than the detection limit to 54.55 CFU.mL-1. In bulk samples before boiling ranged from lower than the detection limit to 2636 CFU.g-1, while after boiling ranged from lower than the detection limit to 72.73 CFU.mL-1. Fungal contamination on tea bags before boiling ranged from lower than the detection limit to 66.67 CFU.g-1 and after boiling, all samples presented results lower than the detection limit. Concerning bulk samples before boiling ranged from lower than the detection limit to 96.97 CFU.g-1, whereas after boiling ranged from lower the detection limit to 30.3 CFU.mL-1. Before boiling, the most common fungal species in the bagged tea (90.91 CFU.g-1; 45.45%) and bulk samples (66.67 CFU.g-1; 91.67%) was Aspergillus section Nigri. Fungal diversity was higher on bulk samples than in tea bags. Aspergillus section Nigri and Rhizopus sp. growth was observed mostly on itraconazole-supplemented Sabouraud dextrose agar media, which require further investigation. Aspergillus sections Fumigati and Nidulantes were detected by using real time PCR, but not in the GT samples in which they were identified through culture-based methods. A significantly reduction of bacterial contamination after boiling was observed, however fungal contamination with toxigenic potential was observed before and after boiling. Future research work needs to characterize in detail the mycotoxins contamination to allow a risk-benefit assessment to estimate the human health benefits and risks following tea consumption and to support policy-actions, if and when needed. The results also suggest that the conditions how tea is packed can influence the fungal diversity and this variable should be further investigated.


Asunto(s)
Antiinfecciosos/farmacología , Aspergillus/aislamiento & purificación , Azoles/farmacología , Bacterias/aislamiento & purificación , Farmacorresistencia Bacteriana/fisiología , Farmacorresistencia Fúngica/fisiología , Té/microbiología , Aspergillus/efectos de los fármacos , Aspergillus/genética , Bacterias/efectos de los fármacos , Bacterias/genética , Contaminación de Alimentos/análisis , Humanos , Pruebas de Sensibilidad Microbiana , Micotoxinas/análisis , Portugal , Reacción en Cadena en Tiempo Real de la Polimerasa
15.
Prep Biochem Biotechnol ; 50(9): 915-924, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32496968

RESUMEN

This paper addresses the issue of combining the usage of waste frying oil (WFO), as a feedstock, and a lipase produced in solid-state fermentation (SSF), as a biocatalyst, for semi-pilot scale production of biodiesel as fatty acid methyl esters (FAME). Two fungal mutants namely; Rhizopus stolonifer 1aNRC11 mutant F (1F) and Aspergillus tamarii NDA03a mutant G (3G) were used as a cocatalyst. The two mutants were cultivated separately by SSF in a tray bioreactor. The dried fermented solid of 1F and 3G mutants were used in a ratio of 3:1, respectively, for WFO transesterification. Optimization of several semi-pilot process stages including SSF and WFO transesterification reaction conditions resulted in 92.3% conversion of WFO to FAME. This FAME yield was obtained after 48 h using 10% cocatalyst (w/w of WFO), 10% water (w/w of WFO) and 3:1 methanol/ WFO molar ratio at 30 °C and 250 rpm. A preliminary economic evaluation of produced biodiesel price (190 $/Ton) is less than half the price of petroleum diesel in Egypt (401$/Ton) and is about 40.3% the price of biodiesel produced using a pure enzyme, which is a promising result. This strategy makes the biodiesel synthesis process greener, economical and sustainable.


Asunto(s)
Aspergillus/metabolismo , Biocombustibles , Proteínas Fúngicas/metabolismo , Lipasa/metabolismo , Aceites de Plantas/metabolismo , Rhizopus/metabolismo , Aspergillus/genética , Aspergillus/crecimiento & desarrollo , Biocombustibles/análisis , Biocombustibles/microbiología , Reactores Biológicos/microbiología , Esterificación , Fermentación , Proteínas Fúngicas/genética , Lipasa/genética , Mutación , Rhizopus/genética , Rhizopus/crecimiento & desarrollo
16.
Curr Microbiol ; 77(7): 1150-1158, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32060767

RESUMEN

The garlic contains sulfur bioactive compounds responsible for medicinal properties. The decrease of these compounds due to inadequate storage conditions reduces the beneficial properties and favors infection by microorganisms. Several studies have shown high frequency of garlic infected with Aspergillus section Nigri that potentially produce mycotoxin. Garlic samples were collected in markets of Brazil and a total of 32 samples (of 36) had the fungal infection with predominant genus Aspergillus (50.3%), Penicillium (34.7%), and Fusarium (11%). A total of 63% (649/1031) of infection with Aspergillus section Nigri, of which 60 isolates were selected for analysis of genetic variability that resulted in 4 clusters. Representatives of clusters were identified by the calmodulin gene. Isolates from cluster I were subdivided into A-I and identified as A. niger (16 isolates) and the isolates of clusters B-I, II, and III were identified as A. welwitschiae (43 isolates). Besides, an isolate of the IV-cluster was identified by A. luchuensis. Further, we used the multiplex PCR to verify genotypes of 59 isolates, and none of these had OTA production-associated genotype. Moreover, 19 A. welwitschiae and 15 A. niger were FB2 production-associated genotype. Our study is the first report to the incidence of garlic infection in Brazil and to show that A. welwitschiae causes most of these infections.


Asunto(s)
Aspergillus , Fumonisinas/metabolismo , Ajo/microbiología , Ocratoxinas/metabolismo , Aspergillus/genética , Aspergillus/metabolismo , Aspergillus/patogenicidad , Brasil , Microbiología de Alimentos , Genotipo
17.
Mycoses ; 63(4): 376-381, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31981256

RESUMEN

BACKGROUND: Chronic pulmonary aspergillosis (CPA) is a progressive respiratory disease, caused most commonly by A fumigatus, with significant morbidity and mortality. Azole resistance in A fumigatus is a growing concern worldwide, with resistance to itraconazole reported in up to 50% of patients. AIM: The aim of this study was to determine whether a positive Aspergillus PCR (polymerase chain reaction) is a marker of resistance in CPA patients on azole therapy. METHODS: Patients were selected via a consecutive database search for the first 50 CPA patients with a positive Aspergillus PCR from January to September 2016. Data were collected regarding concurrent and subsequent culture results, current therapy and serum antifungal levels. PCR-positive patients not on therapy were included as the control group. RESULTS: Twenty-three patients were on therapy (15 itraconazole, 4 voriconazole and 4 posaconazole). Cycle threshold (Ct) values ranged from 20.8 to 37.9; no significant difference was found between each treatment and the control group (P = .47). In treated patients, concurrent azole-resistant A fumigatus was found in 75% of A fumigatus-positive cultures (6/8). All of the resistant isolates in the itraconazole group showed therapy resistance. Twenty per cent of all itraconazole levels were sub-therapeutic. No significant difference was found in serum itraconazole levels for patients on itraconazole with a positive PCR versus negative PCR (P = .44). CONCLUSION: Positive sputum, Aspergillus-specific PCR can be associated with azole resistance in CPA patients on therapy.


Asunto(s)
Aspergillus fumigatus/aislamiento & purificación , Azoles/uso terapéutico , Farmacorresistencia Fúngica , Aspergilosis Pulmonar/tratamiento farmacológico , Antifúngicos/uso terapéutico , Aspergillus/efectos de los fármacos , Aspergillus/genética , Aspergillus/aislamiento & purificación , Aspergillus fumigatus/efectos de los fármacos , Femenino , Proteínas Fúngicas/genética , Humanos , Masculino , Reacción en Cadena de la Polimerasa , Estudios Retrospectivos
18.
Int J Food Microbiol ; 319: 108496, 2020 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-31911209

RESUMEN

Cassiae Semen (CS) has been widely used as roasted tea and traditional Chinese medicine for decades. However, CS is easily contaminated by fungi and mycotoxins during pre-harvest and post-harvest process, thus posing a potential threat to consumer health. In this study, we used the Illumina MiSeq PE300 platform and targeted the internal transcribed spacer 2 sequences to survey the occurrence of fungi in raw and roasted CS samples. Results showed the fungal contamination in all 12 test samples. Ascomycota was the prevailing fungus at the phylum level, with the relative abundance of 66.50%-99.42%. At the genus level, Aspergillus, Cladosporium, and Penicillium were the most dominant genera, accounting for 0.66%-85.51%, 0.20%-29.11%, and 0.11%-32.92% of the fungal reads, respectively. A total of 68 species were identified, among which six potential toxigenic fungi belonging to Aspergillus, Penicillium, Candida, and Schizophyllum genera were detected. Moreover, differences in fungal communities were observed in raw and roasted CS samples. In conclusion, amplicon sequencing is feasible for analyzing fungal communities in CS samples, which provides a new approach to investigate the fungal contamination in edible-medicinal herb, thereby ensuring food safety and drug efficacy.


Asunto(s)
Cinnamomum aromaticum/microbiología , Hongos/clasificación , Hongos/genética , Polen/microbiología , Aspergillus/genética , Candida/genética , Cladosporium/genética , ADN Intergénico/genética , Contaminación de Alimentos/análisis , Inocuidad de los Alimentos/métodos , Hongos/aislamiento & purificación , Secuenciación de Nucleótidos de Alto Rendimiento , Medicina Tradicional China , Micobioma , Micotoxinas/análisis , Penicillium/genética , Té/microbiología
19.
J Environ Sci Health B ; 55(3): 210-219, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31653182

RESUMEN

In the present study, ethanolic extract from Heliopsis longipes roots and affinin/spilanthol against Aspergillus parasiticus growth and aflatoxins production were studied in relation to the expression of aflD and aflR, two key genes of aflatoxins biosynthetic pathway. Phytochemical analysis of the ethanolic extract by GC-EIMS identified affinin/spilanthol (7.84 ± 0.27 mg g-1) as the most abundant compounds in H. longipes roots. The antifungal and anti-aflatoxigenic assays showed that affinin/spilanthol at 300 µg mL-1 produced the higher inhibition of radial growth (95%), as well as, the higher aflatoxins production inhibition (61%) in comparison to H. longipes roots (87% and 48%, respectively). qRT-PCR revealed that the expression of aflD and aflR genes showed a higher downregulation in affinin/spilanthol at 300 µg mL-1. The expression ratio of alfD was suppressed by affinin/spilanthol in 79% and aflR in 84%, while, a lower expression ratio suppressed by H. longipes was obtained, alfD (55%) and aflR (59%). Affinin/spilanthol possesses higher antifungal and anti-aflatoxigenic activity against A. parasiticus rather than H. longipes roots, and this anti-aflaxotigenic activity occurring via downregulation of the aflD and aflR genes. Thus, H. longipes roots and affinin/spilanthol can be considered potent antifungal agents against aflatoxigenic fungus, especially, affinin/spilanthol.


Asunto(s)
Antifúngicos/farmacología , Aspergillus/efectos de los fármacos , Asteraceae/química , Extractos Vegetales/farmacología , Alcamidas Poliinsaturadas/farmacología , Aflatoxinas/biosíntesis , Aflatoxinas/genética , Antifúngicos/química , Aspergillus/genética , Aspergillus/metabolismo , Vías Biosintéticas , Proteínas de Unión al ADN/genética , Regulación hacia Abajo , Proteínas Fúngicas/genética , Regulación Fúngica de la Expresión Génica/efectos de los fármacos , Extractos Vegetales/química , Raíces de Plantas/química , Alcamidas Poliinsaturadas/análisis , Factores de Transcripción/genética
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