Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 32
Filter
1.
Arq. Inst. Biol ; 86: e0172019, 2019. tab
Article in English | LILACS, VETINDEX | ID: biblio-1045963

ABSTRACT

With the objective to evaluate the efficiency of essential oils of Citrus latifolia (Tahiti lemon) and Cinnamomum zeylanicum (cinnamon bark) in the control of plant pathogens Penicillium sp. and Aspergillus sp. and the quality of the bean seeds, two experiments were conducted. In the first one, the effect of essential oils of C. latifolia and C. zeylanicum was evaluated in vitro development of the fungi Penicillium sp. and Aspergillus sp. and, in the second one, the influence of essential oils on the physiological and sanitary quality of bean seeds. The variables mycelial growth, conidial germination and sporulation of Penicillium sp. and Aspergillus sp. were measured in the first experiment, while the seed germination test, first count of germination, germination speed index (GSI) and sanity test of bean seeds were measured in the second. The essential oil (EO) of C. zeylanicum was more efficient than C. latifolia in the control of Aspergillus sp. and Penicillium sp., but decreased the physiological quality of the beans seeds. The fungal diversity identified in the seed health test was composed by fungi of the genera Aspergillus, Penicillium, Cladosporium, Fusarium, Chaetomium and Rhizopus. The results indicate the potential of the use of these EOs in the seeds treatment.(AU)


Com o objetivo de avaliar a eficiência dos óleos essenciais de Citrus latifolia (limão taiti) e Cinnamomum zeylanicum (canela em casca) no controle dos fitopatógenos Penicillium sp. e Aspergillus sp. e na qualidade das sementes de feijão, foram conduzidos dois experimentos. No primeiro, avaliou-se o efeito dos óleos essenciais de C. latifolia e C. zeylanicum no desenvolvimento in vitro dos fungos Penicillium sp. e Aspergillus sp. e, no segundo, a influência dos óleos essenciais sobre a qualidade fisiológica e sanitária das sementes de feijão. As variáveis crescimento micelial, germinação de conídios e esporulação de Penicillium sp. e Aspergillus sp. foram aferidas no primeiro experimento, enquanto o teste de germinação de sementes, primeira contagem de germinação, índice de velocidade de germinação (IVG) e teste de sanidade de sementes de feijão foram aferidas no segundo. O óleo essencial (OE) de C. zeylanicum foi mais eficiente que C. latifolia no controle dos fungos Aspergillus sp. e Penicillium sp., mas diminuiu a qualidade fisiológica das sementes de feijão. A diversidade fúngica identificada no teste de sanidade de sementes foi composta por fungos dos gêneros Aspergillus, Penicillium, Cladosporium, Fusarium, Chaetomium e Rhizopus. Os resultados indicam o potencial do uso desses óleos essenciais no tratamento de sementes.(AU)


Subject(s)
Oils, Volatile , Cinnamomum zeylanicum , Citrus , Phaseolus/microbiology , Mitosporic Fungi/growth & development , Penicillium/growth & development , Aspergillus/growth & development , Food Quality , Germination , Phaseolus/physiology
2.
Braz. j. microbiol ; 49(4): 865-871, Oct.-Dec. 2018. tab, graf
Article in English | LILACS | ID: biblio-974297

ABSTRACT

ABSTRACT The ability of four Aspergillus strains for biosynthesis of kojic acid was evaluated among which Aspergillus terreus represented the highest level (2.21 g/L) of kojic acid production. Improvement kojic acid production ability of A. terreus by random mutagenesis using different exposure time to ultraviolet light (5-40 min) was then performed to obtain a suitable mutant of kojic acid production (designated as C5-10, 7.63 g/L). Thereafter, design of experiment protocol was employed to find medium components (glucose, yeast extract, KH2PO4 (NH4)2SO4, and pH) influences on kojic acid production by the C5-10 mutant. A 25-1 fractional factorial design augmented to central composite design showed that glucose, yeast extract, and KH2PO4 were the most considerable factors within the tested levels (p < 0.05). The optimum medium composition for the kojic acid production by the C5-10 mutant was found to be glucose, 98.4 g/L; yeast extract, 1.0 g/L; and KH2PO4, 10.3 mM which was theoretically able to produce 120.2 g/L of kojic acid based on the obtained response surface model for medium optimization. Using these medium compositions an experimental maximum Kojic acid production (109.0 ± 10 g/L) was acquired which verified the efficiency of the applied method.


Subject(s)
Pyrones/metabolism , Aspergillus/radiation effects , Aspergillus/metabolism , Aspergillus/growth & development , Aspergillus/genetics , Ultraviolet Rays , Mutagenesis , Culture Media/metabolism , Fermentation , Glucose/metabolism
3.
Braz. j. microbiol ; 49(2): 407-413, Apr.-June 2018. tab, graf
Article in English | LILACS | ID: biblio-889247

ABSTRACT

Abstract Fungal infections have become a concern for health professionals, and the emergence of resistant strains has been reported for all known classes of antifungal drugs. Among the fungi causing disease, we highlight those that belong to the genus Aspergillus. For these reasons, the search for new antifungals is important. This study examines the effects of a coumarin derivative, 4-acetatecoumarin (Cou-UMB16) both alone and together with antifungal drugs, and its mode of action against Aspergillus spp. Cou-UMB16 was tested to evaluate its effects on mycelia growth, and germination of Aspergillus spp. fungal conidia. We investigated its possible action on cell walls, on the cell membrane, and also the capacity of this coumarin derivative to enhance the activity of antifungal drugs. Our results suggest that Cou-UMB16 inhibits Aspergillus spp. virulence factors (mycelia growth and germination of conidia) and affects the structure of the fungal cell wall. When applying Cou-UMB16 in combination with azoles, both synergistic and additive effects were observed. This study concludes that Cou-UMB16 inhibits mycelial growth and spore germination, and that the activity is due to its action on the fungal cell wall, and that Cou-UMB16 could act as an antifungal modifier.


Subject(s)
Antifungal Agents/isolation & purification , Antifungal Agents/pharmacology , Aspergillus/drug effects , Coumarins/isolation & purification , Coumarins/pharmacology , Drug Synergism , Aspergillus/growth & development , Azoles/pharmacology , Cell Membrane/drug effects , Cell Wall/drug effects , Hyphae/drug effects , Hyphae/growth & development , Spores, Fungal/drug effects , Spores, Fungal/growth & development
4.
Braz. j. microbiol ; 49(supl.1): 229-235, 2018. tab, graf
Article in English | LILACS | ID: biblio-974342

ABSTRACT

ABSTRACT Gallesia integrifolia (Phytolaccaceae) is native to Brazil and has a strong alliaceous odor. The objective of this study was to identify the chemical composition of G. integrifolia fruit essential oil and evaluate fungicidal activity against the main food-borne diseases and food spoilage fungi. The essential oil was extracted by hydrodistillation and identified by GC-MS. From 35 identified compounds, 68% belonged to the organosulfur class. The major compounds were dimethyl trisulfide (15.49%), 2,8-dithianonane (52.63%) and lenthionine (14.69%). The utilized fungi were Aspergillus fumigatus, Aspergillus niger, Aspergillus ochraceus, Aspergillus versicolor, Penicillium funiculosum, Penicillium ochrochloron, Penicillium verrucosum var. cyclopium, and Trichoderma viride. Minimal fungicidal concentration for the essential oil varied from 0.02 to 0.18 mg/mL and bifonazole and ketoconazole controls ranged from 0.20 to 3.50 mg/mL. The lower concentration of the essential oil was able to control P. ochrochloron, A. fumigatus, A. versicolor, A. ochraceus and T. viride. This study shows a high fungicidal activity of G. integrifolia fruit essential oil and can support future applications by reducing the use of synthetic fungicides.


Subject(s)
Plant Oils/pharmacology , Oils, Volatile/pharmacology , Phytolaccaceae/chemistry , Fungicides, Industrial/pharmacology , Penicillium/growth & development , Penicillium/drug effects , Aspergillus/growth & development , Aspergillus/drug effects , Plant Oils/chemistry , Brazil , Oils, Volatile/chemistry , Microbial Sensitivity Tests , Fruit/chemistry , Fungicides, Industrial/chemistry , Gas Chromatography-Mass Spectrometry
5.
Bol. micol. (Valparaiso En linea) ; 31(1): 2-18, jun. 2016. tab, graf
Article in Spanish | LILACS | ID: biblio-868807

ABSTRACT

Las especies del género Aspergillus Link constituyen importantes agentes biodeteriorantes de objetos de valor constructivo, cultural y patrimonial. En ambientes laborales, sus propágulos y metabolitos pueden provocar afecciones a la salud humana. Los estudios aeromicológicos pueden contribuir a minimizar el impacto de Aspergillus spp. en el biodeterioro y la calidad de vida. Se han caracterizado de acuerdo a su potencial biodeterió- geno y patogénico representantes de Aspergillus spp. en el aire de depósitos de materiales en tres instituciones patrimoniales cubanas. Las muestras se tomaron empleando un biocolector SAS súper 100. Se evaluó cualitativamente la actividad celulolítica, amilolítica y proteolítica de los aislados; así como la excreción de pigmentos y ácidos orgánicos. Se evaluó el crecimiento a 37°C y la secreción de hemolisinas. Aspergillus spp. constituyó parte considerable de la micobiota aérea viable en los depósitos con 22 especies correspondientes a 12 secciones, las de mayor variabilidad fueron Flavi y Restricti, mientras la primera y la sección Aspergillus fueron las mejor representadas. El 74 por ciento de las cepas mostraron alta capacidad para degradar los compuestos orgánicos evaluados y secretar ácidos, mientras el 34 por ciento excretó pigmentos de amarillo a pardo oscuro, se evidenció un amplio potencial biodeteriorante en general. Más del 30 por ciento de los aislados mostraron ser patógenos oportunistas peligrosos para el hombre al crecer a 37°C, secretar hemolisinas, y presentar un tamaño conidial que posibilita la depositación en alvéolos pulmonares. Las cepas con mayor impacto biodeteriorante y patogénico fueron las correspondientes a las Secciones Flavi, Nigri y la especie Aspergillus fumigatus Fresen.


Species of the genus Aspergillus Link cause damage to objects constructive, cultural and heritage value. In work environments, their propagules and metabolites may cause disorders to human health. Aerobiological studies can help minimize the impact of Aspergillus spp. in the biodeterioration and quality of life. Aspergillus spp. strains present in the air of the repositories in three Cuban heritage institutions were characterized according to their biodeteriogenic and pathogenic potential. Each isolated was classified taxonomically, cellulolytic, amylolytic and proteolytic activity as well as excretion of pigments and organic acids was evaluated. The capacity to grow at 37°C and secrete hemolysins was qualitatively evaluated. Aspergillus spp. was significant portion of viable air micobiota in the three repositories with 22 species corresponding to 12 sections, most variability were Flavi and Restricti, while the first section and Aspergillus were the best represented. The 74 percent of the strains showed high ability to degrade organic compounds evaluated and secrete acids, while 34 percent excreted pigments from yellow to dark brown, evidenced a broad biodeteriogenic potential in general. More than 30 percent of the isolates were shown to be dangerous opportunistic pathogens for humans to grow at 37°C, secrete hemolysin, and present a conidial size which enables the deposition pulmonary alveoli. Strains higher biodeteriogenic and pathogenic impact were those corresponding to the Flavi, Nigri sections and the species Aspergillus fumigatus Fresen.


Subject(s)
Humans , Aspergillus/classification , Aspergillus/growth & development , Aspergillus/pathogenicity , Biodegradation, Environmental , Cellulose , Hydrolysis , Cuba , Culture Media , Coloring Agents/toxicity , Mycobiome , Plant Components, Aerial
6.
Braz. j. microbiol ; 46(3): 937-941, July-Sept. 2015. ilus
Article in English | LILACS | ID: lil-755825

ABSTRACT

In this study, we evaluated the effect of low and high molecular weight polycyclic aromatic hydrocarbons (PAHs), i.e., Phenanthrene, Pyrene and Benzo[a]pyrene, on the radial growth and morphology of the PAH-degrading fungal strains Aspergillus nomius H7 and Trichoderma asperellum H15. The presence of PAHs in solid medium produced significant detrimental effects on the radial growth of A. nomius H7 at 4,000 and 6,000 mg L−1 and changes in mycelium pigmentation, abundance and sporulation ability at 1,000–6,000 mg L−1. In contrast, the radial growth of T. asperellum H15 was not affected at any of the doses tested, although sporulation was observed only up to 4,000 mg L−1 and as with the H7 strain, some visible changes in sporulation patterns and mycelium pigmentation were observed. Our results suggest that fungal strains exposed to high doses of PAHs significantly vary in their growth rates and sporulation characteristics in response to the physiological and defense mechanisms that affect both pigment production and conidiation processes. This finding is relevant for obtaining a better understanding of fungal adaptation in PAH-polluted environments and for developing and implementing adequate strategies for the remediation of contaminated soils.

.


Subject(s)
Aspergillus/growth & development , Benzo(a)pyrene/pharmacology , Mycelium/drug effects , Phenanthrenes/pharmacology , Polycyclic Aromatic Hydrocarbons/pharmacology , Pyrenes/pharmacology , Spores, Fungal/drug effects , Trichoderma/growth & development , Aspergillus/drug effects , Aspergillus/metabolism , Biodegradation, Environmental , Polycyclic Aromatic Hydrocarbons/metabolism , Soil Microbiology , Soil Pollutants , Trichoderma/drug effects , Trichoderma/metabolism
7.
Braz. j. microbiol ; 45(4): 1485-1492, Oct.-Dec. 2014. graf, tab
Article in English | LILACS | ID: lil-741304

ABSTRACT

Filamentous fungi are considered to be the most important group of microorganisms for the production of plant cell wall degrading enzymes (CWDE), in solid state fermentations. In this study, two fungal strains Aspergillus niger MS23 and Aspergillus terreus MS105 were screened for plant CWDE such as amylase, pectinase, xylanase and cellulases (β-glucosidase, endoglucanase and filterpaperase) using a novel substrate, Banana Peels (BP) for SSF process. This is the first study, to the best of our knowledge, to use BP as SSF substrate for plant CWDE production by co-culture of fungal strains. The titers of pectinase were significantly improved in co-culture compared to mono-culture. Furthermore, the enzyme preparations obtained from monoculture and co-culture were used to study the hydrolysis of BP along with some crude and purified substrates. It was observed that the enzymatic hydrolysis of different crude and purified substrates accomplished after 26 h of incubation, where pectin was maximally hydrolyzed by the enzyme preparations of mono and co-culture. Along with purified substrates, crude materials were also proved to be efficiently degraded by the cocktail of the CWDE. These results demonstrated that banana peels may be a potential substrate in solid-state fermentation for the production of plant cell wall degrading enzymes to be used for improving various biotechnological and industrial processes.


Subject(s)
Aspergillus/enzymology , Aspergillus/growth & development , Hydrolases/metabolism , Musa/metabolism , Musa/microbiology , Aspergillus/metabolism , Coculture Techniques , Fermentation
8.
Braz. j. microbiol ; 45(3): 885-892, July-Sept. 2014. ilus, graf, tab
Article in English | LILACS | ID: lil-727017

ABSTRACT

India is amongst the largest banana (Musa acuminata) producing countries and thus banana pseudo stem is commonly available agricultural waste to be used as lignocellulosic substrate. Present study focuses on exploitation of banana pseudo stem as a source for bioethanol production from the sugars released due to different chemical and biological pretreatments. Two fungal strains Aspergillus ellipticus and Aspergillus fumigatus reported to be producing cellulolytic enzymes on sugarcane bagasse were used under co-culture fermentation on banana pseudo stem to degrade holocellulose and facilitate maximum release of reducing sugars. The hydrolysate obtained after alkali and microbial treatments was fermented by Saccharomyces cerevisiae NCIM 3570 to produce ethanol. Fermentation of cellulosic hydrolysate (4.1 g%) gave maximum ethanol (17.1 g/L) with yield (84%) and productivity (0.024 g%/h) after 72 h. Some critical aspects of fungal pretreatment for saccharification of cellulosic substrate using A. ellipticus and A. fumigatus for ethanol production by S. cerevisiae NCIM 3570 have been explored in this study. It was observed that pretreated banana pseudo stem can be economically utilized as a cheaper substrate for ethanol production.


Subject(s)
Aspergillus/metabolism , Biofuels , Ethanol/metabolism , Industrial Waste , Musa/metabolism , Plant Stems/metabolism , Saccharomyces cerevisiae/metabolism , Aspergillus/growth & development , India , Saccharomyces cerevisiae/growth & development
9.
Afr. j. infect. dis. (Online) ; 8(1): 1-4, 2014. ilus
Article in English | AIM, AIM | ID: biblio-1257270

ABSTRACT

Background: It is important to find reliable and accessible methods for the diagnosis and identification of fungal species causing hospital acquired infections. Our main objective was using a rapid and accessible molecular method for the monitoring of Aspergillus infections and identification of causing agents in the level of species. Material and Methods: The study subjects were primarily clinical specimens collected from suspected HAI patients with clinical symptoms after hospitalization. Also some environmental specimens were collected from air and instruments of health care facilities for the investigation of Aspergillus sources in a university hospital of UMSU, Urmia. All specimens were transported to Medical Mycology Center for the detection and identification of Aspergillus species using morphological methods. Also molecular method, PCR-RFLP using single restriction enzyme as a rapid and available method was performed to investigate environmental sources of Aspergillus infections. Results: Total of 110 clinical fungal isolates included Candida and Aspergillus species and some other opportunistic fungi. Among the clinical Aspergillus findings, Aspergillus flavus (47%), Aspergillus fumigatus (29.4%) and Aspergillus niger (23.6%) were the most frequent species respectively and also Aspergillus niger (43.7%), Aspergillus flavus (41.8%), Aspergillus fumigatus (14.7%) were isolated as the most frequent species from environmental sources. Conclusion: Because of accessibility, speed and high sensitivity of diagnosis, the PCR-RFLP was very useful for the identification of medically important Aspergillus species and epidemiological approaches


Subject(s)
Aspergillus flavus , Aspergillus fumigatus , Aspergillus niger , Aspergillus/epidemiology , Aspergillus/growth & development , Epidemiological Monitoring , Molecular Diagnostic Techniques
10.
Braz. j. microbiol ; 45(1): 97-104, 2014. ilus, tab
Article in English | LILACS | ID: lil-709484

ABSTRACT

Polygalacturonase and α-amylase play vital role in fruit juice industry. In the present study, polygalacturonase was produced by Aspergillus awamori Nakazawa MTCC 6652 utilizing apple pomace and mosambi orange (Citrus sinensis var mosambi) peels as solid substrate whereas, α-amylase was produced from A. oryzae (IFO-30103) using wheat bran by solid state fermentation (SSF) process. These carbohydrases were decolourized and purified 8.6-fold, 34.8-fold and 3.5-fold, respectively by activated charcoal powder in a single step with 65.1%, 69.8% and 60% recoveries, respectively. Apple juice was clarified by these decolourized and partially purified enzymes. In presence of 1% polygalacturonase from mosambi peels (9.87 U/mL) and 0.4% α-amylase (899 U/mL), maximum clarity (%T660nm = 97.0%) of juice was attained after 2 h of incubation at 50 ºC in presence of 10 mM CaCl2. Total phenolic content of juice was reduced by 19.8% after clarification, yet with slightly higher %DPPH radical scavenging property.


Subject(s)
Aspergillus/enzymology , Beverages , Food Handling/methods , Polygalacturonase/isolation & purification , Polygalacturonase/metabolism , alpha-Amylases/isolation & purification , alpha-Amylases/metabolism , Aspergillus/growth & development , Culture Media/chemistry , Free Radical Scavengers/analysis , Phenols/analysis , Temperature , Time Factors
11.
Braz. j. microbiol ; 45(1): 313-321, 2014. ilus, tab
Article in English | LILACS | ID: lil-709491

ABSTRACT

Biosynthesis of active secondary metabolites by fungi occurs as a specific response to the different growing environments. Changes in this environment alter the chemical and biological profiles leading to metabolites diversification and consequently to novel pharmacological applications. In this work, it was studied the influence of three parameters (fermentation length, medium composition and aeration) in the biosyntheses of antimicrobial metabolites by the fungus Aspergillus parasiticus in 10 distinct fermentation periods. Metabolism modulation in two culturing media, CYA and YES was evaluated by a 2² full factorial planning (ANOVA) and on a 2³ factorial planning, role of aeration, medium composition and carbohydrate concentration were also evaluated. In overall, 120 different extracts were prepared, their HPLC profiles were obtained and the antimicrobial activity against A. flavus, C. albicans, E. coli and S. aureus of all extracts was evaluated by microdilution bioassay. Yield of kojic acid, a fine chemical produced by the fungus A. parasiticus was determined in all extracts. Statistical analyses pointed thirteen conditions able to modulate the production of bioactive metabolites by A. parasiticus. Effect of carbon source in metabolites diversification was significant as shown by the changes in the HPLC profiles of the extracts. Most of the extracts presented inhibition rates higher than that of kojic acid as for the extract obtained after 6 days of fermentation in YES medium under stirring. Kojic acid was not the only metabolite responsible for the activity since some highly active extracts showed to possess low amounts of this compound, as determined by HPLC.


Subject(s)
Anti-Infective Agents/metabolism , Aspergillus/metabolism , Aspergillus/drug effects , Aspergillus/growth & development , Candida albicans/drug effects , Culture Media/chemistry , Escherichia coli/drug effects , Fermentation , Microbial Sensitivity Tests , Staphylococcus aureus/drug effects
12.
Biol. Res ; 47: 1-5, 2014. ilus, graf, tab
Article in English | LILACS | ID: biblio-950731

ABSTRACT

BACKGROUND: The whitish tender leaves of Palmyrah are used for making handicrafts. The problem with these articles is discolouration with time and become more brittle due to fungal attack. This could be prevented by some protective coating. Instead of expensive and harmful chemicals we decided to test natural plant essential oils to control fungal attack. Palmyrah leaf article decay fungi were isolated from two different sites of Jaffna peninsula. In this investigation Antifungal Activity of different plant essential oils from neem (Azadirachta indica), castor (Ricinus communis), citronella (Cymbopogon sp) and camphor (Cinnamomum camphora) obtained from local market have been evaluated against isolated fungi. For screening of Antifungal activity, tests and controls were set to determine minimum inhibitory concentration (MIC) and Percentage of Growth Inhibition. RESULTS: Morphologically three different types of Palmyrah leaf decay fungi were isolated and characterized asAspergillus niger, Aspergillus flavus and Penicillium sp. Neem and castor oils have recorded no significant (0.05 > P) antifungal activity while citronella and camphor oils showed significantly different antifungal activity compared with control. Camphor oil and Citronella oil showed 100, 58.13% of average growth inhibition for A. niger. 96.38, 51.32% for A.flavus and 84.99, 72.76% forPenicillium sp respectively. Camphor oil showed highest percentage of growth inhibition at lowest minimum inhibitory concentration compared with citronella oil. Camphor oil was found to be highly antifungal and most effective against A niger, and A. flavus, compared with Penicillium sp and gave 100 percentage of growth inhibitions at 5, 1 and 15 ml/dl minimum inhibitory concentration respectively. CONCLUSION: Significantly higher broad-spectrum of antifungal activity was observed in camphor oil than other tested oils because it showed highest percentage of growth inhibition at lowest inhibitory concentration. Therefore it could be used for the development of new environmental friendly antifungal agent for the preservation of leafy handicrafts. Further formulation, field experiments are necessary to achieve this target.


Subject(s)
Penicillium/drug effects , Aspergillus/drug effects , Plant Oils/pharmacology , Oils, Volatile/pharmacology , Arecaceae/microbiology , Growth Inhibitors/pharmacology , Antifungal Agents/pharmacology , Penicillium/isolation & purification , Penicillium/growth & development , Aspergillus/isolation & purification , Aspergillus/growth & development , Aspergillus flavus/isolation & purification , Aspergillus flavus/growth & development , Aspergillus flavus/drug effects , Aspergillus niger/isolation & purification , Aspergillus niger/growth & development , Aspergillus niger/drug effects , Ricinus/chemistry , Microbial Sensitivity Tests/methods , Cinnamomum camphora/chemistry , Azadirachta/chemistry , Cymbopogon/chemistry
13.
Braz. j. microbiol ; 44(2): 569-576, 2013. graf, tab
Article in English | LILACS | ID: lil-688590

ABSTRACT

The production of xylanase, β-xylosidase, ferulic acid esterase and β-glucosidase by Aspergillus awamori 2B.361 U2/1, a hyper producer of glucoamylase and pectinase, was evaluated using selected conditions regarding nitrogen nutrition. Submerged cultivations were carried out at 30 ºC and 200 rpm in growth media containing 30 g wheat bran/L as main carbon source and either yeast extract, ammonium sulfate, sodium nitrate or urea, as nitrogen sources; in all cases it was used a fixed molar carbon to molar nitrogen concentration of 10.3. The use of poor nitrogen sources favored the accumulation of xylanase, β-xylosidase and ferulic acid esterase to a peak concentrations of 44,880; 640 and 118 U/L, respectively, for sodium nitrate and of 34,580, 685 and 170 U/L, respectively, for urea. However, the highest β-glucosidase accumulation of 10,470 U/L was observed when the rich organic nitrogen source yeast extract was used. The maxima accumulation of filter paper activity, xylanase, β-xylosidase, ferulic acid esterase and β-glucosidase by A. awamori 2B.361 U2/1 was compared to that produced by Trichoderma reesei Rut-C30. The level of β-glucosidase was over 17-fold higher for the Aspergillus strain, whereas the levels of xylanase and β-xylosidase were over 2-fold higher. This strain also produced ferulic acid esterase (170 U/L), which was not detected in the T. reesei culture.


Subject(s)
Aspergillus/enzymology , Carboxylic Ester Hydrolases/metabolism , Xylosidases/metabolism , beta-Glucosidase/metabolism , Aspergillus/genetics , Aspergillus/growth & development , Carbon/metabolism , Culture Media/chemistry , Nitrogen/metabolism , Temperature
14.
Braz. j. microbiol ; 44(2): 649-655, 2013. ilus, tab
Article in English | LILACS | ID: lil-688596

ABSTRACT

This study aims at evaluating the effects of Zataria multiflora (Z. multiflora) essential oil (EO) on growth, aflatoxin production and transcription of aflatoxin biosynthesis pathway genes. Total RNAs of Aspergillus parasiticus (A.parasiticus) ATCC56775 grown in yeast extract sucrose (YES) broth medium treated with Z. multiflora EO were subjected to reverse transcription-polymerase chain reaction (RT-PCR). Specific primers of nor-1, ver-1, omt-A and aflR genes were used. In parallel mycelial dry weight of samples were measured and all the media were assayed by high-pressure liquid chromatography (HPLC) for aflatoxinB1 (AFB1), aflatoxinB2 (AFB2), aflatoxinG1 (AFG1), aflatoxinG2 (AFG2) and aflatoxin total (AFTotal) production. The results showed that mycelial dry weight and aflatoxin production reduce in the presence of Z. multiflora EO (100 ppm) on day 5 of growth. It was found that the expression of nor-1, ver-1, omt-A and aflR genes was correlated with the ability of fungus to produce aflatoxins on day 5 in YES medium. RT-PCR showed that in the presence of Z.multiflora EO (100 ppm) nor-1, ver-1 and omtA genes expression was reduced. It seems that toxin production inhibitory effects of Z. multiflora EO on day 5 may be at the transcription level and this herb may cause reduction in aflatoxin biosynthesis pathway genes activity.


Subject(s)
Aflatoxins/biosynthesis , Antifungal Agents/metabolism , Aspergillus/drug effects , Biosynthetic Pathways/drug effects , Lamiaceae/chemistry , Oils, Volatile/metabolism , Transcription, Genetic/drug effects , Antifungal Agents/isolation & purification , Aspergillus/genetics , Aspergillus/growth & development , Aspergillus/metabolism , Biosynthetic Pathways/genetics , Chromatography, High Pressure Liquid , Gene Expression Profiling , Oils, Volatile/isolation & purification , Reverse Transcriptase Polymerase Chain Reaction
15.
Iranian Journal of Public Health. 2012; 41 (6): 72-79
in English | IMEMR | ID: emr-124848

ABSTRACT

The effect of curcumin as a natural safe compound with different biological activities was examined on fungal growth and aflatoxin production in Aspergillus parasiticus NRRL 2999. The fungus was cultured in presence of serial two-fold concentrations of curcumin [125-2000 micro g/ml] in yeast extract sucrose broth for 3 days at 28°C. Mycelia dry weight was determined as an index of fungal growth, while aflatoxin production was assessed by high performance liquid chromatography [HPLC]. The expression of ver-1, nor-1, pksA, omtA and aflR genes in aflatoxin biosynthetic pathway was evaluated by real time PCR. Curcumin strongly inhibited aflatoxin B1 production in the range of 26.6 to 94.9% by serial two-fold concentrations from 125 to 2000 micro g/ml. Fungal growth was also inhibited by the compound in the range of 34.0 to 60.8%. Analysis of the expression of aflatoxin pathway genes by real time PCR showed that curcumin inhibited the expression of ver-1, nor-1, pksA, omtA and aflR genes at concentrations of 250 and 1000 micro g/ml. In concentration of 1000 micro g/ml, gene expression was reduced by 31.3%, 44.6%, 57.1% 110.9% and 286.7% accordingly. Reduction in the expression of aflatoxin biosynthesis genes was significant only for aflR. In ferric reducing ability of plasma [FRAP] assay, curcumin showed strong antioxidant activity at all concentrations tested. Curcumin may be employed successfully as a good candidate in controlling of toxigenic fungal growth on food and feed and subsequent contamination with aflatoxins in practice


Subject(s)
Aspergillus/growth & development , Aflatoxins/biosynthesis , Gene Expression , Chromatography, High Pressure Liquid
16.
IJB-Iranian Journal of Biotechnology. 2011; 9 (1): 50-55
in English | IMEMR | ID: emr-122388

ABSTRACT

The continuous production of polygalacturonases [PGases] that Exo-polygalacturonase [exo-PGase] and Endo-polygalacturonase [endo-PGase] are two members of this group by a strain of Aspergillus awamori in surface culture fermentation was investigated. Surface culture fermentation is usually done in batch mode. Wheat flour acted as a good substrate for the cultivation of the fungus and production of PGases in surface culture fermentation. Fermentation started in batch mode until mycelia completely occupied the medium following growth of the microorganism, after which it was turned to the continuous mode by the introduction of fresh feed. The process continued for 34 days, and the thickness of the microbial layer on the surface of the liquid medium became almost constant after approximately one week. The production of PGases, however, continued throughout the experiment, and maximum activities of 1.2 U/ml and 0.014 U/ml were obtained for exo-polygalacturonase [exo- PGase] and endo-polygalacturonase [endo-PGase], respectively. An increase in production was observed when a similar system was used with a line for medium recycling. Lowering the residence time to 12 h decreased the exo-PGase and endo-PGase activities. Reducing the residence time from 24 h to 12 h almost halved the concentrations of the enzymes at the outlet


Subject(s)
Aspergillus/enzymology , Aspergillus/growth & development , Fermentation , Triticum/metabolism , Biotechnology/methods , Culture Media/chemistry
17.
Rev. bras. anal. clin ; 43(1): 42-45, 2011. graf, tab
Article in Portuguese | LILACS | ID: lil-695626

ABSTRACT

Com o intuito de caracterizar a freqüência de fungos anemófilos do gênero em ambiente hospitalardurante o período de reformas, coletou-se o ar interno e externo do Centro de Terapia Intensivo (CTI) adulto e, o ar do centro cirúrgico, em dois diferentes pontos. O primeiro, há cerca de um metro da reforma e, o segundo ponto, há 10 metros de distância. As coletas foram realizadas em um hospital do oeste do estado de Santa Catarina, durante o mês de fevereiro de2008, nos períodos da manhã e da tarde, três vezes por semana. Foram coletadas 52 amostras, onde houve o isolamento de 323 colônias de fungos anemófilos, sendo que destes, 11 amostras (21%) continham colônias típicas de Aspergillus , dos quais nenhum era da espécie A. niger ou A. flavus , ou seja, as 32 colônias (10%) isoladas pertenciam exclusivamente à espécie A. fumigatus. A caracterização dos fungos de ambientes internos de áreas críticas de hospitais tem sido mundialmente reconhecida como importante medida visando reduzir substancialmente a morbidade, mortalidade e os altos custos hospitalares. O monitoramento de contaminantes ambientais em hospitais deve ser frequentemente realizado, principalmente em área especiais com pacientes imunocomprometidos, sujeitos à exposição de patógenos do meioambiente.


With the intention of characterizing the frequency of airborne spoilage fungi from Aspergillus genus in hospitalatmosphere during the period of reforms, was collected the internal and external air of adult Intensive Therapy Center (ITC) and the air of the surgical center, in two different places. The first, about a meter of the reform and the second point, there are 10 meters away. The collections were accomplished in the west hospital from Santa Catarina state, during the month of February of 2008, in the period of the morning and of the afternoon, three times a week. Starting from 52 samples, there was the isolation of 323 colonies of airborne fungi, and of these, 11 samples (21%) had typical colonies of Aspergillus genus, noneof which was the species A. niger or A. flavus, ie, the 32 colonies (10%) isolates belonged exclusively to the species A. fumigatus. The characterization of the moulds of internal atmospheres of critical areas of hospitals has globally been recognized as important measure seeking to reduce the morbidity, mortality and the high hospital costs substantially. This way, the environmental sources monitory should be realized, mainly in special rooms with immunosuppressed patient,subjects to the exhibition of pathogen environment.


Subject(s)
Air Monitoring , Air Samples , Aspergillus/growth & development , Aspergillus/isolation & purification , Cross Infection , Hospital Design and Construction
18.
Bol. micol ; 23: 49-66, dic. 2008. ilus, tab
Article in Spanish | LILACS | ID: lil-585733

ABSTRACT

Se condensan los principales alcances en el género Aspergillus y las metodologías de diagnóstico morfo-taxonómico de las especies más comunes de utilidad para el micólogo en áreas clínicas y ambientales. Se aporta información bibliográfica actualizada para las determinaciones polifásicas de las especies y algunas claves morfofisiológicas tentativas en ciertos taxa de importancia médica, con énfasis en la Sección Fumigati.


The main information about the Aspergillus genus together with methodologies for the morphotaxonomic diagnosis of the most common species useful for the mycologist in clinical and environmental areas are here condensed. An updated bibliography is forwarded in order to carry out polyphasic identification of the species as well as tentative morphophysiological keys in some taxa having medical significance with emphasis in Section Fumigati.


Subject(s)
Aspergillus fumigatus , Aspergillus/isolation & purification , Aspergillus/classification , Aspergillus/growth & development , Aspergillus/physiology , Aspergillus/pathogenicity
19.
Braz. j. microbiol ; 39(2): 362-367, Apr.-June 2008. graf, tab
Article in English | LILACS | ID: lil-487719

ABSTRACT

Origanum vulgare L. (Lamiaceae) has been currently known for their interesting antimicrobial activity being regarded as alternative antimicrobial for use is food conservation systems. This study aimed to evaluate the effectiveness of O. vulgare essential oil in inhibiting the growth of some food-related Aspergillus species (A. flavus, A. parasiticus, A. terreus, A. ochraceus, A. fumigatus and A. niger). The essential oil revealed a strong anti-Aspergillus property providing an inhibition of all assayed mould strains. MIC values were between 80 and 20 µL/mL being found a MIC50 of 40 µL/mL. The essential oil at concentration of 80 and 40 µL/mL provided a fungicidal effect on A. flavus, A. fumigatus and A. niger noted by a total inhibition of the radial mycelial growth along 14 days of interaction. In addition, the essential oil was able to inhibit the mould spores germination when assayed at concentrations of 80 and 40 µL/mL. Our results showed the interesting anti-Aspergillus activity of O. vulgare essential oil supporting their possible use as anti-mould compound in food conservation.


Origanum vulgare L. (Lamiaceae) tem sido atualmente reconhecido por sua intensa atividade antimicrobiana sendo considerado como fonte de compostos antimicrobianos alternativos para uso em sistemas de conservação de alimentos. Este estudo objetivou avaliar a efetividade do óleo essencial de O. vulgare em inibir o crescimento de algumas espécies de Aspergillus (A. flavus, A. parasiticus, A. terreus and A. fumigatus) de interesse em alimentos. O óleo essencial revelou uma forte atividade atni-Aspergillus provocando a inibição de todas as cepas fúngicas ensaiadas. Os valores de MIC estiveram entre 80 e 20 µL/mL sendo encontrado uma MIC50 de 40 µL/mL. O óleo essencial nas concentrações de 80 e 40 µL/mL causou um efeito fungicida sobre A. flavus, A. fumigatus e A. niger notado por uma total inibição do crescimento micelial radial ao longo de 14 dias de interação, bem como foi capaz de inibir a germinação de esporos destas cepas fúngicas. Nossos resultados mostram a intensa atividade anti-Aspergillus do óleo essencial de O. vulgare suportando o seu possível uso como antifúngico em sistemas de conservação de alimentos.


Subject(s)
Antifungal Agents , Aspergillus/growth & development , Aspergillus/isolation & purification , Food Preservation , In Vitro Techniques , Lamiaceae , Oils, Volatile/analysis , Origanum/analysis , Origanum/isolation & purification , Food Microbiology , Food Samples , Methods
20.
Braz. j. microbiol ; 39(1): 91-97, Jan.-Mar. 2008. graf, tab
Article in English | LILACS | ID: lil-480682

ABSTRACT

Cinnamomum zeylanicum Blume is known for a wide range of medicinal properties. This study aimed to assess the interference of C. zeylanicum essential oil on the growth and morphogenesis of some potentially pathogenic Aspergillus species. The essential oil presented strong antifungal effect causing the growth inhibition of the assayed strains and development of large growth inhibition zones. MIC50 and MIC90 values were 40 and 80 µL/mL, respectively. 80, 40 and 20 µL/mL of the oil strongly inhibited the radial mycelial growth of A. niger, A. flavus and A. fumigatus along 14 days. 80 and 40 µL/mL of the oil caused a 100 percent inhibition of the fungal spore germination. Main morphological changes observed under light microscopy provided by the essential oil in the fungal strains were decreased conidiation, leakage of cytoplasm, loss of pigmentation and disrupted cell structure indicating fungal wall degeneration. It is concluded that C. zeylanicum essential oil could be known as potential antifungal compound, particularly, to protect against the growth of Aspergillus species.


Cinnamomum zeylanicum Blume é uma planta conhecida por apresentar ampla variedade de propriedades medicinais. Portanto, este estudo teve por objetivo avaliar a interferência do óleo essencial C. zeylanicum sobre o crescimento e morfogênese de algumas espécies de Aspergillus potencialmente patogênicas. O óleo essencial testado apresentou potente efeito antifúngico demonstrado pela visualização de grandes zonas de inibição de crescimento de todas as linhagens testadas. Os valores de CIM50 e de CIM90 foram 40 e 80 µL/mL, respectivamente. Nas concentrações de 80, 40 e 20 µL/mL o óleo demonstrou um potente efeito fumigante, inibindo o crescimento micelial radial de A. niger, A. flavus e A. fumigatus ao longo de 14 dias de exposição. A 80 e 40 µL/mL o óleo essencial promoveu inibição de 100 por cento da germinação de esporos, das três espécies de Aspergillus citadas anteriormente. Além disso, alterações morfológicas no crescimento fúngico foram observadas sob microscopia óptica após exposição ao óleo essencial, como diminuição da conidiação, perda citoplasmática, perda de pigmentação e rompimento da estrutura fúngica (hifa) indicando degeneração da parede celular. Diante do exposto, conclui-se que o óleo essencial de C. zeylanicum poderia ser empregado como potente composto antifúngico, particularmente, prevenindo crescimento de espécies de Aspergillus.


Subject(s)
Antifungal Agents , Aspergillus/growth & development , Aspergillus/isolation & purification , Aspergillus/pathogenicity , Cinnamomum zeylanicum/growth & development , In Vitro Techniques , Oils, Volatile/classification , Methods , Morphogenesis , Virulence
SELECTION OF CITATIONS
SEARCH DETAIL