RESUMEN
ABSTRACT The objective was to evaluate the inoculation with Aspergillus terreus and/or Trichoderma longibrachiatum on fermentation, chemical and microbiological composition of elephant grass 'Cameroon' silage (Cenchrus purpureus). Treatments were A. terreus at 105 colony forming units (CFU)/g (AT15), T. longibrachiatum at 105 CFU/g (TL20), a mixture of both at 105 CFU/g (MIX), and a control group without inoculation (CONTR). The design was completely randomized with seven replicates. The MIX silage was most stable, while CONTR, AT15, and TL20, had lower dry matter losses. There was no effect of inoculation in the chemical composition of silages. Only MIX silage (4.40) had pH above the minimum of 4.2 for humid grass silage and above the control (4.05). Bacteria from Diplococcus genus was identified at the opening of TL20 and CONTR silages. After air exposure, the population of rods, Lactobacillus, and total lactic acid bacteria was higher in theTL20 and MIX. The inclusion of a T. longibrachiatum and A. terreus mixture increases dry mater loss and silage pH. T. longibrachiatum was more efficient in maintaining populations of total lactic acid bacteria after opening; therefore, this strain has potential as an additive for elephant grass 'Cameroon' silage.
RESUMO O objetivo foi testar a inoculação com Aspergillus terreus e Trichoderma longibrachiatum sobre a fermentação, a composição bromatológica e microbiológica de silagem de capim-elefante cultivar 'Cameroon' (Cenchrus purpureus). Os tratamentos foram A. terreus a 105 unidades formadores de colônias (UFC)/g (AT15), T. longibrachiatum a 105 UFC/g (TL20), a mistura de ambos a 105 UFC/g (MIX), cada, e um controle não inoculado (CONTR). O delineamento foi inteiramente ao acaso, com sete repetições. A silagem MIX foi mais estável após abertura, enquanto CONTR, AT15 e TL20 apresentaram menor perda de massa seca. Não houve efeito de inoculação sobre a composição bromatológica das silagens. Apenas a silagem MIX (4,40) apresentou pH acima do mínimo de 4,2 para silagem de capim úmido e superior ao controle (4,05). Bactérias do gênero Diplococcus foram identificadas na abertura das silagens TL20 e CONTR. Após exposição ao ar, a população de bastonetes, Lactobacillus e bactérias láticas totais foram maiores em TL20 e MIX. A mistura de T. longibrachiatum e A. terreus aumenta a perda de matéria seca e o pH da silagem. T. longibrachiatum é mais eficiente em manter as populações de bactérias láticas totais após a abertura. Portanto, essa cepa tem potencial como aditivo para silagem de capim-elefante 'Cameroon'.
RESUMEN
Herbivorous insects are known to be resistant to fungal endophytes that asymptomatically inhabit plant tissues. The insecticidal ability of the endophytic fungus Aspergillus terreus isolated from Catharanthus roseus against Spodoptera litura (Fabricius) was assessed in the current study. The survival and growth of S. litura were adversely impacted by the ethyl acetate extract of endophytic A. terreus. Fungal extract supplemented diet caused 14 to 94% larval mortality in comparison to 2% in control. Additionally, retarded insect growth was observed after ingestion of supplemented diet. The fungal metabolites were also observed to have an inhibitory influence on the adult emergence and reproductive potential of adults. Phytochemical analysis revealed the presence of phenolic compounds in the crude extract of endophytic fungus which may be responsible for toxicity. It was also determined how endophyte-infected cauliflower plants affected S. litura's survival and growth. Endophyte-infected plants exhibited resistance to S. litura by causing 54% larval mortality and delaying development by 5.2 days. In comparison to uninfected plants, adult emergence, lifespan, fecundity and egg hatchability of insects was significantly decreased on infected plants. There was a significant decrease in relative growth and consumption rates as well as in the efficiency of food conversion, which indicates toxic and antifeedant effect of the fungus on S. litura. This suggests that endophyte-inoculated plants exhibit antibiosis against S. litura. In conclusion, the endophytic fungi having insecticidal activity could be used to develop alternative ecologically safe control strategies.
Asunto(s)
Insecticidas , Mariposas Nocturnas , Animales , Spodoptera , Herbivoria , Aspergillus , Larva , Endófitos , Insecticidas/farmacologíaRESUMEN
Invasive infections caused by filamentous fungi have increased considerably due to the alteration of the host's immune response. Aspergillus terreus is considered an emerging pathogen and has shown resistance to amphotericin B treatment, resulting in high mortality. The development of fungal biofilm is a virulence factor, and it has been described in some cases of invasive aspergillosis. In addition, although the general composition of fungal biofilms is known, findings related to biofilms of a lipid nature are rarely reported. In this study, we present the identification of a clinical strain of A. terreus by microbiological and molecular tools, also its in vitro biofilm development capacity: (i) Biofilm formation was quantified by Crystal Violet and reduction of tetrazolium salts assays, and simultaneously the stages of biofilm development were described by Scanning Electron Microscopy in High Resolution (SEM-HR). (ii) Characterization of the organizational structure of the biofilm was performed by SEM-HR. The hyphal networks developed on the surface, the abundant air channels created between the ECM (extracellular matrix) and the hyphae fused in anastomosis were described. Also, the presence of microhyphae is reported. (iii) The chemical composition of the ECM was analyzed by SEM-HR and CLSM (Confocal Laser Scanning Microscopy). Proteins, carbohydrates, nucleic acids and a relevant presence of lipid components were identified. Some structures of apparent waxy appearance were highlighted by SEM-HR and backscatter-electron diffraction, for which CLSM was previously performed. To our knowledge, this work is the first description of a lipid-type biofilm in filamentous fungi, specifically of the species A. terreus from a clinical isolate.
Asunto(s)
Aspergillus , Biopelículas , Hongos , Encéfalo , LípidosRESUMEN
This work aimed to evaluate the lovastatin (Lv) production by solid-state fermentation (SSF) from selected crop residues, considering the post-fermented residues as feed supplements for ruminants. The SSF was performed with two substrates (wheat bran and oat straw) and two A. terreus strains (CDBB H-194 and CDBB H-1976). The Lv yield, proximate analysis, and organic compounds by GC-MS in the post-fermented residues were assessed. The combination of the CDBB H-194 strain with oat straw at 16 d of incubation time showed the highest Lv yield (23.8 mg/g DM fed) and the corresponding degradation efficiency of hemicellulose + cellulose was low to moderate (24.1%). The other three treatments showed final Lv concentrations in decreasing order of 9.1, 6.8, and 5.67 mg/g DM fed for the oat straw + CDBB H-1976, wheat bran + CDBB H-194, and wheat bran + CDBB H-1976, respectively. An analysis of variance of the 22 factorial experiment of Lv showed a strong significant interaction between the strain and substrate factors. The kinetic of Lv production adequately fitted a zero-order model in the four treatments. GC-MS analysis identified only a couple of compounds from the residues fermented by A. terreus CDBB H-194 (1,3-dipalmitin trimethylsilyl ether in the fermented oat straw and stearic acid hydrazide in the fermented wheat bran) that could negatively affect ruminal bacteria and fungi. Solid-state fermentation of oat straw with CDBB H-194 deserves further investigation due to its high yield of Lv; low dietary proportions of this post-fermented oat straw could be used as an Lv-carrier supplement for rumen methane mitigation.
RESUMEN
BACKGROUND Hydroxycinnamic acids and some of their derivatives are molecules with interesting biological activities; for instance, hydroxylated hydroxycinnamic esters have proved to have antifungal properties, and thus the generation of these molecules is of industrial importance. In this study, the direct esterification capacity of the pure recombinant type B feruloyl esterase from Aspergillus terreus (AtFAE B) was evaluated by its ability to catalyze the synthesis of isobutyl o-coumarate, an interesting antifungal molecule. A ternary solvent system (isooctane/isobutanol/water) was employed to improve the synthesis of isobutyl o-coumarate, assessing different substrate concentrations, enzyme load, water percentages and pH and temperature values. RESULTS AtFAE B showed the highest initial rate at 18% (v/v) isobutanol and 50 mM o-coumaric acid, 0.04 mg/ml of enzyme, 4% (v/v) water without buffer and 40C. AtFAE B half-lives at 30C, 40C and 50C were 16.5 h, 1.75 h and 3.5 min, respectively. Thus, we decided to evaluate the bioconversion yield at 30C, where the enzyme showed the highest operational stability. At this temperature, we obtained a yield of ~80% after only 8 h of reaction, using a 78:18:4 isooctane:isobutanol:water ternary solvent system, with 50 mM of o-coumaric acid.CONCLUSIONS Under these improved conditions, the productivity was 1.06 g isobutyl o-coumarate/L*h with a biocatalyst yield of 209.6 kg isobutyl o-coumarate/kg free AtFAE B, demonstrating the promising potential of AtFAE B to accept the non-canonical o-coumaric acid as the substrate and to achieve the synthesis of isobutyl o-coum
Asunto(s)
Aspergillus/metabolismo , Cumarinas/metabolismo , Antifúngicos/metabolismo , Aspergillus/enzimología , Solventes/metabolismo , Cumarinas/uso terapéutico , Antifúngicos/uso terapéuticoRESUMEN
The emergence of azole resistant Aspergillus spp., especially Aspergillus fumigatus, has been described in several countries around the world with varying prevalence depending on the country. To our knowledge, azole resistance in Aspergillus spp. has not been reported in the West Indies yet. In this study, we investigated the antifungal susceptibility of clinical and environmental isolates of Aspergillus spp. from Martinique, and the potential resistance mechanisms associated with mutations in cyp51A gene. Overall, 208 Aspergillus isolates were recovered from clinical samples (n = 45) and environmental soil samples (n = 163). They were screened for resistance to azole drugs using selective culture media. The Minimum Inhibitory Concentrations (MIC) towards voriconazole, itraconazole, posaconazole and isavuconazole, as shown by the resistant isolates, were determined using the European Committee on Antimicrobial Susceptibility Testing (EUCAST) microdilution broth method. Eight isolates (A. fumigatus, n = 6 and A. terreus, n = 2) had high MIC for at least one azole drug. The sequencing of cyp51A gene revealed the mutations G54R and TR34/L98H in two A. fumigatus clinical isolates. Our study showed for the first time the presence of azole resistance in A. fumigatus and A. terreus isolates in the French West Indies.
RESUMEN
Aspergillus terreus can produce different holocellulose-degrading enzymes when grown in sugarcane bagasse, with predominant pectinase activity. Thus, pectinase was selected for purification and immobilization studies. Ion exchange and molecular exclusion chromatography studies were performed, after which it was possible to semipurify the enzyme with a yield of 80%. The crude extract pectinase (PECEB) and the partially purified enzyme (PEC2) were immobilized on monoamino-N-aminoethyl (MANAE)-agarose with pectinase activity yields of 66% and 98%, respectively. After immobilization in MANAE-agarose, the pectinase showed higher activity at acidic pH (pH 4.0) when compared to the nonimmobilized enzyme. It was also found that after the immobilization process, there was a threefold improvement in the enzyme's thermostability. Also, it was possible to reuse the immobilized enzyme for up to five cycles of hydrolysis with effective production of reducing sugars (0.196 mg/g of substrate). The industrial application test revealed a significant decrease in the viscosity of guava juice when the immobilized enzyme was used. PECEB, immobilized on MANAE-agarose, was the enzyme sample that generated the highest pulp viscosity reduction (approximately 47%). Although additional studies are needed for practical industrial application, the results obtained herein reveal the potential of application of immobilized pectinase in the industry.
Asunto(s)
Aspergillus/enzimología , Enzimas Inmovilizadas/química , Proteínas Fúngicas/química , Poligalacturonasa/química , Estabilidad de EnzimasRESUMEN
Proteases can be used in several biotechnological processes including detergent, food and leather industries. In the leather industry, dehairing is carried out by chemicals, which pollute the environment. Therefore, to make the hair removal process environmentally friendly, a protease produced by Aspergillus terreus has been purified, biochemically characterized and had an efficient ability to remove hair from bovine leather. The protease was produced using 1% wheat bran and was purified 2.3-fold using two chromatographic steps showing a molecular weight of 90 kDa. Optimal temperature and pH were 50 °C and 6.5, respectively. Thermal stability was up to 1 h at 50 °C. Protease was stable to detergents like Tween 80 and to organic solvents. The activity was activated by Ca2+ and inhibited by Hg2+ and Cu2+. The enzyme was classified as serine protease, by the inhibition by PMSF and was stable to reducing agents. It hydrolyzed casein, azocasein, BSA, egg albumin and BTpNA. The Km and Vmax values were 0.65 ± 0.03 mg/mL and 3.66 ± 0.18 µmol/min, respectively. Remarkable properties about temperature, pH, stability to detergents and reducing agents ensure that the protease from A. terreus can be an excellent candidate for industrial applications, particularly in the leather industry.
Asunto(s)
Aspergillus/enzimología , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Tecnología Química Verde/métodos , Remoción del Cabello/métodos , Serina Proteasas/química , Serina Proteasas/metabolismo , Animales , Biotecnología/métodos , Calcio/metabolismo , Bovinos , Cobre/metabolismo , Detergentes/química , Activación Enzimática , Estabilidad de Enzimas , Proteínas Fúngicas/aislamiento & purificación , Concentración de Iones de Hidrógeno , Hidrólisis , Mercurio/metabolismo , Peso Molecular , Sustancias Reductoras/química , Serina Proteasas/aislamiento & purificación , Solventes/química , TemperaturaRESUMEN
Lovastatin is a drug in the statin class which acts as a natural inhibitor of 3-hydroxy-3-methylglutaryl, a coenzyme reductase reported as being a potential therapeutic agent for several diseases: Alzheimer's, multiple sclerosis, osteoporosis and due to its anti-cancer properties. Aspergillus terreus is known for producing a cholesterol reducing drug. This study sets out to evaluate the production of lovastatin by Brazilian wild strains of A. terreus isolated from a biological sample and natural sources. Carbon and nitrogen sources and the best physicochemical conditions using factorial design were also evaluated. The 37 fungal were grown to produce lovastatin by submerged fermentation. A. terreus URM5579 strain was the best lovastatin producer with a level of 13.96 mg/L. Soluble starch and soybean flour were found to be the most suitable substrates for producing lovastatin (41.23 mg/L) and biomass (6.1 mg/mL). The most favorable production conditions were found in run 16 with 60 g/L soluble starch, 15 g/L soybean flour, pH 7.5, 200 rpm and maintaining the solution at 32 °C for 7 days, which led to producing 100.86 mg/L of lovastatin and 17.68 mg/mL of biomass. Using natural strains and economically viable substrates helps to optimize the production of lovastatin and promote its use.
Asunto(s)
Aspergillus/metabolismo , Biotecnología/métodos , Lovastatina/biosíntesis , Biomasa , Brasil , Carbono , Colesterol/química , Cromatografía Líquida de Alta Presión , Fermentación , Concentración de Iones de Hidrógeno , Nitrógeno , Glycine max , Espectrofotometría Ultravioleta , Almidón/química , Temperatura , Factores de TiempoRESUMEN
Given the global abundance of plant biomass residues, potential exists in biorefinery-based applications with lignocellulolytic fungi. Frequently isolated from agricultural cellulosic materials, Aspergillus terreus is a fungus efficient in secretion of commercial enzymes such as cellulases, xylanases and phytases. In the context of biomass saccharification, lignocellulolytic enzyme secretion was analyzed in a strain of A. terreus following liquid culture with sugarcane bagasse (SB) (1% w/v) and soybean hulls (SH) (1% w/v) as sole carbon source, in comparison to glucose (G) (1% w/v). Analysis of the fungal secretome revealed a maximum of 1.017 UI.mL-1 xylanases after growth in minimal medium with SB, and 1.019 UI.mL-1 after incubation with SH as carbon source. The fungal transcriptome was characterized on SB and SH, with gene expression examined in comparison to equivalent growth on G as carbon source. Over 8000 genes were identified, including numerous encoding enzymes and transcription factors involved in the degradation of the plant cell wall, with significant expression modulation according to carbon source. Eighty-nine carbohydrate-active enzyme (CAZyme)-encoding genes were identified following growth on SB, of which 77 were differentially expressed. These comprised 78% glycoside hydrolases, 8% carbohydrate esterases, 2.5% polysaccharide lyases, and 11.5% auxiliary activities. Analysis of the glycoside hydrolase family revealed significant up-regulation for genes encoding 25 different GH family proteins, with predominance for families GH3, 5, 7, 10, and 43. For SH, from a total of 91 CAZyme-encoding genes, 83 were also significantly up-regulated in comparison to G. These comprised 80% glycoside hydrolases, 7% carbohydrate esterases, 5% polysaccharide lyases, 7% auxiliary activities (AA), and 1% glycosyltransferases. Similarly, within the glycoside hydrolases, significant up-regulation was observed for genes encoding 26 different GH family proteins, with predominance again for families GH3, 5, 10, 31, and 43. A. terreus is a promising species for production of enzymes involved in the degradation of plant biomass. Given that this fungus is also able to produce thermophilic enzymes, this first global analysis of the transcriptome following cultivation on lignocellulosic carbon sources offers considerable potential for the application of candidate genes in biorefinery applications.
RESUMEN
BACKGROUND: Central nervous system involvement due to aspergillosis is an extremely serious entity, particularly in patients with severe neutropenia, hematological diseases, or post-transplant cases. Immunocompetent patients can be infected by intense exposure, particularly iatrogenic after invasive procedures. CASE DESCRIPTION: We present the case of a 26-year-old male with a 1 year appendectomy background, which required epidural anesthesia. After that surgery, insidious headache presented, requiring mild analgesics for adequate control. In the following weeks, headaches increased and tomographic imaging revealed hydrocephalus. A ventriculoperitoneal shunt was placed, and empirical treatment for neurocysticercosis was established, but diagnosis was never confirmed. Sequentially, shunt dysfunction occurred twice, for which shunt replacement was performed. Cerebrospinal fluid and shunt's catheter were cultured. Some days later, a filamentous fungus was isolated and finally identified as Aspergillus sp. Intravenous amphotericin B and fluconazole at therapeutic dosage were administered; however, a torpid clinical evolution was observed. After a 2-week antifungal scheme, the fungus was identified as Aspergillus terreus. The patient developed sudden rostrocaudal deterioration. Computed tomography imaging was done, revealing a 70 cc hematoma in the right operculoinsular region, midline shift, and a 9 mm saccular aneurysm at the bifurcation of the middle cerebral artery. CONCLUSION: Cerebral aspergillosis is a serious disease with high mortality in patients, particularly those without identifiable risk factors. The iatrogenic forms are serious, due to the delay of clinical diagnosis. It is important to have a high index of suspicion in patients with a history of invasive procedures such as epidural anesthesia or surgery, and who develop a persistent chronic headache or chronic meningitis.
RESUMEN
The ability to produce second-generation itaconic acid by Aspergillus terreus, and the inhibitory effects of hydrolysis by-products on the fermentation were evaluated by cultivation in a synthetic medium containing components usually present in a real hydrolysate broth from lignocellulosic biomasses. The results showed that A. terreus NRRL 1960 can produce itaconic acid and consume xylose completely, but the conversion is less than the fermentation using only glucose. In addition, compared to fermentation of glucose, or even xylose, the mix of both sugars resulted in a lower itaconic acid yield. In the inhibitory test, the final itaconic acid titer was reduced by acetic acid, furfural, and 5-hydroxymethylfurfural concentrations of, respectively, 188, 175, and 700 mg L-1. However, the presence of any amount of acetic acid proved to be detrimental to itaconic acid production. This research sheds some light on doubts about the biorefinery implementation of itaconic acid production.
Asunto(s)
Aspergillus , Succinatos , Biomasa , FermentaciónRESUMEN
Filamentous fungi are well known for producing secondary metabolites applied in various industrial segments. Among these, lovastatin and itaconic acid, produced by Aspergillus terreus, have applications in the pharmaceutical and chemical industries. Lovastatin is primarily used for the control of hypercholesterolemia, while itaconic acid is a building block for the production of synthetic fibers, coating adhesives, among others. In this study, for the first time, 35 strains of Aspergillus sp. from four Brazilian culture collections were evaluated for lovastatin and itaconic acid production and compared to a reference strain, ATCC 20542. From an initial screening, the strains ATCC 20542, URM 224, URM1876, URM 5061, URM 5254, URM 5256, URM 5650, and URM 5961 were selected for genomic comparison. Among tested strains, the locus corresponding to the lovastatin genomic cluster was assembled, showing that all genes essential for lovastatin biosynthesis were present in producing URM 5961 and URM 5650 strains, with 100% and 98.5% similarity to ATCC 20542, respectively. However, in the no producing URM 1876, URM 224, URM 5254, URM 5061, and URM 5256 strains, this cluster was either fragmented or missing. Among the 35 strains evaluated for itaconic acid production in this study, only three strains had titers above 0.5 g/L, 16 strains had production below 0.5 g/L, and the remaining 18 strains had no production, with the highest production of itaconic acid observed in the URM 5254 strain with 2.2 g/L. The essential genes for itaconic acid production, mttA, cadA msfA were also mapped, where all three genes linked to itaconic acid production were found in a single contig in the assembly of each strain. In contrast to lovastatin loci, there is no correlation between the level of itaconic acid production and genetic polymorphisms in the genes associated with its biosynthesis.
Asunto(s)
Aspergillus , Lovastatina , Succinatos , Aspergillus/genética , Aspergillus/metabolismo , Biodiversidad , Brasil , Genes Fúngicos , Variación Genética , Genoma Fúngico , Lovastatina/biosíntesis , Lovastatina/genética , Filogenia , Succinatos/metabolismoRESUMEN
AIMS: The aim of this study was to find new eukaryotic sources of the l-asparaginase (l-ASNase), since the prokaryotic sources of the enzyme are well-reported as causing allergic hypersensitivity reactions in a significant number of patients. This report describes screening for l-ASNase production by filamentous fungi isolated from the Brazilian Caatinga, and the optimization of fermentation parameters to increase fungal growth and improve yield in the production of l-ASNase. METHODS AND RESULTS: Thirty-two filamentous fungi were investigated in this study. When Aspergillus terreus strain S-18 was cultured in a proline-enriched medium, intracellular l-ASNase was expressed in concurrence with reduced l-glutaminase (l-GLUase) and protease activities. Fermentation conditions were then optimized in a 5-l bioreactor system to produce a maximum volumetric yield of 108 U total of l-ASNase activity. CONCLUSIONS: The work reported here represents the first attempt to produce l-ASNase by filamentous fungi isolated from Brazil and offers a promising alternative eukaryotic source for l-ASNase production. SIGNIFICANCE AND IMPACT OF THE STUDY: In order to minimize the side effects caused by bacterial l-ASNase, the search of eukaryotic micro-organism for l-ASNase was carried out in fungi. This study demonstrates the diversity of filamentous fungi isolated from the Brazilian Caatinga Biome and the importance of knowledge of the microbial metabolism to obtain high concentrations of biotechnological products.
Asunto(s)
Asparaginasa , Aspergillus , Reactores Biológicos/microbiología , Asparaginasa/análisis , Asparaginasa/metabolismo , Aspergillus/química , Aspergillus/enzimología , Aspergillus/metabolismo , Brasil , Microbiología Ambiental , Fermentación , Bosques , MicrobiotaRESUMEN
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 (540 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.(AU)
RESUMEN
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.
Asunto(s)
Pironas/metabolismo , Aspergillus/efectos de la radiación , Aspergillus/metabolismo , Aspergillus/crecimiento & desarrollo , Aspergillus/genética , Rayos Ultravioleta , Mutagénesis , Medios de Cultivo/metabolismo , Fermentación , Glucosa/metabolismoRESUMEN
Brasilanones A-F and asperterreusines A-C, undescribed brasilane sesquiterpenoids and dihydrobenzofuran derivatives, were isolated from the marine-derived fungus Aspergillus terreus [CFCC 81836]. Their structures with absolute configurations were elucidated on the basis of spectroscopic data, X-ray crystallographic analyses, and electronic circular dichroism (ECD) calculations. Brasilanones A-F are unusual brasilane sesquiterpenoids with an α,ß-unsaturated ketone unit, interestingly, brasilanones B-D are stereo isomers. All of the isolates were evaluated for their inhibitory activities against NO production and cytotoxic activities against five human cancer cell lines (HL-60, SW-480, A-549, MCF-7, and SMMC-7721). Brasilanones A and E showed moderate inhibitory effect with NO inhibition rates of 47.7% (pâ¯<â¯0.001) and 37.3% (pâ¯<â¯0.001) at the concentration of 40⯵M. Asperterreusines A showed cytotoxicity against HL-60 and SW-480â¯cell lines with IC50 values of 15.3 and 25.7⯵M, respectively.
Asunto(s)
Antiinflamatorios no Esteroideos/farmacología , Antineoplásicos Fitogénicos/farmacología , Aspergillus/química , Benzofuranos/farmacología , Óxido Nítrico/antagonistas & inhibidores , Sesquiterpenos/farmacología , Animales , Antiinflamatorios no Esteroideos/química , Antiinflamatorios no Esteroideos/aislamiento & purificación , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/aislamiento & purificación , Benzofuranos/química , Benzofuranos/aislamiento & purificación , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Cristalografía por Rayos X , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Lipopolisacáridos/antagonistas & inhibidores , Lipopolisacáridos/farmacología , Ratones , Modelos Moleculares , Conformación Molecular , Óxido Nítrico/biosíntesis , Células RAW 264.7 , Sesquiterpenos/química , Sesquiterpenos/aislamiento & purificación , Relación Estructura-ActividadRESUMEN
The ability of four Aspergillus strains for biosynthesis of kojic acid was evaluated among which Aspergillus terreus represented the highest level (2.21g/L) of kojic acid production. Improvement kojic acid production ability of A. terreus by random mutagenesis using different exposure time to ultraviolet light (5-40min) was then performed to obtain a suitable mutant of kojic acid production (designated as C5-10, 7.63g/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, 98.4g/L; yeast extract, 1.0g/L; and KH2PO4, 10.3mM which was theoretically able to produce 120.2g/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±10g/L) was acquired which verified the efficiency of the applied method.
Asunto(s)
Aspergillus/metabolismo , Aspergillus/efectos de la radiación , Pironas/metabolismo , Aspergillus/genética , Aspergillus/crecimiento & desarrollo , Medios de Cultivo/metabolismo , Fermentación , Glucosa/metabolismo , Mutagénesis , Rayos UltravioletaRESUMEN
La aspergilosis invasora es una infección oportunista causada por hongos del género Aspergillus spp, considerándose la con peor pronóstico producida por este organismo. Presenta una elevada tasa de mortalidad a pesar del avance en los tratamientos antifúngicos, afectando principalmente a pacientes inmunosuprimidos. Dentro de las formas clínicas se encuentra la que sucede posterior a una cirugía conllevando una elevada morbi-mortalidad. Presentamos un caso clínico del Hospital Roberto Del Río. Recién nacido de término diagnosticado de transposición de grandes vasos, quien a los 9 días de vida es sometido a cirugía correctora. Egresa de pabellón con tórax abierto y con requerimiento de drogas vasoactivas. Al décimo día postoperatorio presenta deterioro hemodinámico, se realiza ecocardiograma que muestra líquido con ecorefringencias y se realiza aseo quirúrgico, extrayendo muestra para cultivo que resulta positivo para Aspergillus terreus. Por consiguiente, se inicia tratamiento con voriconazol con buena respuesta clínica...
Invasive aspergillosis is an opportunistic infection caused by fungi of the genus Aspergillus spp, considered the worst prognosis produced by this organism. It has a high mortality despite progress in antifungal treatments, affecting mainly immunocompromised patients. Clinically can occur following surgery , leading to high morbidity and mortality. We report a case of Roberto Del Río Hospital. Term newborn diagnosed with transposition of the great vessels, who at 9 days of life undergoes corrective surgery. Leaves the pavilion with open chest and requirement of vasoactive drugs. On the tenth day after surgery presents hemodynamic deterioration, the echocardiogram shows refringence and surgical cleaning is performed, a sample is removed and cultured resulting positive for Aspergillus terreus. Therefore, treatment with voriconazole starts with good clinical response...
Asunto(s)
Humanos , Masculino , Recién Nacido , Aspergilosis/diagnóstico , Aspergilosis/tratamiento farmacológico , Complicaciones Posoperatorias/microbiología , Procedimientos Quirúrgicos Cardíacos/efectos adversos , Aspergillus/aislamiento & purificaciónRESUMEN
Filamentous fungi are attractive hosts for heterologous protein expression due to their capacity to secrete large amounts of enzymes into the extracellular medium. Xyloglucanases, which specifically hydrolyze xyloglucan, have been recently applied in lignocellulosic biomass degradation and conversion in many other industrial processes. In this context, this work aimed to clone, express, and determine the functional properties of a recombinant xyloglucanase (AtXEG12) from Aspergillus terreus, and also its solid-state (SSF) and submerged (SmF) fermentation in bioreactors. The purified AtXEG12 showed optimum pH and temperature of 5.5 and 65 °C, respectively, demonstrating to be 90 % stable after 24 h of incubation at 50 °C. AtXEG12 activity increased in the presence of 2-mercaptoethanol (65 %) and Zn+2 (45 %), while Cu+2 and Ag+ ions drastically decreased its activity. A substrate assay showed, for the first time for this enzyme's family, xylanase activity. The enzyme exhibited high specificity for tamarind xyloglucan (K M 1.2 mg mL-1) and V max of 17.4 µmol min-1 mg-1 of protein. The capillary zone electrophoresis analysis revealed that AtXEG12 is an endo-xyloglucanase. The heterologous xyloglucanase secretion was greater than the production by wild-type A. terreus cultivated in SmF. On the other hand, AtXEG12 activity reached by SSF was sevenfold higher than values achieved by SmF, showing that the expression of recombinant enzymes can be significantly improved by cultivation under SSF.