Myrothecium Verrucaria Research Articles

Myrothecium verrucaria causing needle blight disease on Blue pine (Pinus wallichiana): molecular characterization and host range

Laboratory and nursery experiments were conducted to identify the causal agent of a needle blight of Pinus wallichiana, a species native to the Western Himalayas. The pathogen was identified as Myrothecium verrucaria, on the basis of morphological, cultural and molecular characterization. BLAST analysis of ITS sequences of the pathogen revealed maximum sequence identity of 99% with M. verrucaria. The sequence is the first of this fungus from P. wallichiana. Phylogenetic analysis grouped all M. verrucaria isolates in a single clade; M. roridum and M. inundatum clustered in separate clades. The pathogen grew optimally at 25 ± 1 °C on oat meal agar, pH 5.5. Inoculation experiments with M. verrucaria demonstrated pathogenicity on Pinus halepensis, Cedrus deodara and Cryptomeria japonica, in addition to Pinus wallichiana.

Removal of rhodamine B from wastewater with the myrothecium verrucaria or denitrifying bacteria which was loaded by zeolite

Removal of rhodamine B from wastewater with the myrothecium verrucaria or denitrifying bacteria which was loaded by zeolite

Transparent, mediator- and membrane-free enzymatic fuel cell based on nanostructured chemically modified indium tin oxide electrodes

We detail a mediator- and membrane-free enzymatic glucose/oxygen biofuel cell based on transparent and nanostructured conducting supports. Chemically modified indium tin oxide nanoparticle modified electrodes were used to substantially increase the active surface area without significantly compromising transparency. Two different procedures for surface nanostructuring were employed, viz. spray-coating and drop-coating. The spray-coated biodevice showed superior characteristics as compared to the drop-coated enzymatic fuel cell, as a result of the higher nanostructured surface area as confirmed by electrochemical characterisation, as well as scanning electron and atomic force microscopy. Subsequent chemical modification with silanes, followed by the immobilisation of either cellobiose dehydrogenase from Corynascus thermophiles or bilirubin oxidase from Myrothecium verrucaria, were performed to obtain the bioanodes and biocathodes, respectively. The optimised biodevice exhibited an OCV of 0.67V and power output of up to 1.4µW/cm2 at an operating voltage of 0.35V. This is considered a significant step forward in the field of glucose/oxygen membrane- and mediator-free, transparent enzymatic fuel cells.

Myrothecium verrucaria F-3851, a producer of laccases transforming phenolic compounds at neutral and alkaline conditions

The conditions of submerged cultivation of the ascomycete Myrothecium verrucaria strain F-3851 were optimized in order to increase the yield of laccase in the culture liquid using the natural sources of carbon and energy (fresh rubbed potato tuber or floured grains of buckwheat, barley, oat, wheat, rye, rice, pea, or haricot). The pH-optima of oxidation of a number of laccase substrates (ABTS, 2,6-dimethoxyphenol, syringaldazine, ferulic acid, p-coumaryl alcohol, and coniferyl alcohol) by laccases of the culture liquid as well as substrate selectivity of laccases were investigated. The intermediates of transformation of phenylpropanoids (ferulic acid, p-coumaryl alcohol and coniferyl alcohol) by laccases of the culture liquid at neutral conditions were purified and identified. The ability of laccases of the culture liquid of M. verrucaria strain F-3851 to catalyze polymer compound formation during phenylpropanoid transformation was shown that offers the prospects of application of the laccases of M. verrucaria strain F-3851 for production of pharmacologically valuable polymers in a number of cellular biotechnologies carried out in neutral or alkaline environments.

Production of Laccase by a New Myrothecium verrucaria MD-R-16 Isolated from Pigeon Pea [Cajanus cajan (L.) Millsp.] and its Application on Dye Decolorization.

The present study was conducted to screen a laccase-producing fungal endophyte, optimize fermentation conditions, and evaluate the decolorization ability of the laccase. A new fungal endophyte capable of laccase-producing was firstly isolated from pigeon pea and identified as Myrothecium verrucaria based on a ITS-rRNA sequences analysis. Meanwhile, various fermentation parameters on the laccase production were optimized via response surface methodology (RSM). The optimal fermentation conditions were a fermentation time of five days, temperature 30 °C and pH 6.22. Laccase activity reached 16.52 ± 0.18 U/mL under the above conditions. Furthermore, the laccase showed effective decolorization capability toward synthetic dyes (Congo red, Methyl orange, Methyl red, and Crystal violet) in the presence of the redox mediator ABTS, with more than 70% of dyes decolorizing after 24 h of incubation. Additionally, the activity of laccase was relatively stable with pH (4.5–6.5) and a temperature range of 35–55 °C. Therefore, the high laccase production of the strain and the new fungal laccase could provide a promising alterative approach for industrial and environmental applications.

Bienzymatic mediatorless sensing of total hydrogen peroxide with catalase and multi-copper enzyme co-adsorbed at carbon nanotube-modified electrodes

The rapid, sensitive, and accurate determination of hydrogen peroxide (H2O2) is of practical importance in physiological, pathological, and environmental fields. In this work, we propose a highly sensitive and selective amperometric biosensor for the detection of hydrogen peroxide. The biosensor consists of a glassy carbon electrode (GCE) covered with multi-walled carbon nanotubes (MWCNTs) and adsorbed enzymes: catalase (Cat) and either laccase (Lac) or bilirubin oxidase (BOX). The stability and durability of the electrode was improved by using glutaraldehyde (GAD). The determination of H2O2 by cyclic voltammetry and chronoamperometry experiments proved the synergy of the laccase and catalase co-adsorbed on the carbon nanotubes. Catalase from bovine liver catalyzed the transformation of H2O2 into water and oxygen, which was further transformed into water by multi-copper enzymes (MCO), either laccase from Trametes versicolor or bilirubin oxidase from Myrothecium verrucaria. The unique property of such a bienzymatic sensing layer is the ability to detect oxygen originating both from catalase activity and from the self-decomposition of H2O2. This makes it possible to evaluate the initial concentration of H2O2 in the analyzed sample.

First Report of Myrothecium verrucaria Causing Leaf Spot of Maize in Pakistan

First Report of <i>Myrothecium verrucaria</i> Causing Leaf Spot of Maize in Pakistan

Verrucarin A and roridin E produced on spinach by Myrothecium verrucaria under different temperatures and CO2 levels.

The behavior of Myrothecium verrucaria, artificially inoculated on spinach, was studied under seven different temperature conditions (from 5 to 35°C) and under eight different combinations of temperature and CO2 concentration (14-30°C and 775-870 or 1550-1650mg/m3). The isolate used for this study was growing well on spinach, and the mycotoxins verrucarin A and roridin E were produced under all tested temperature and CO2 conditions. The maximum levels of verrucarin A (18.59ng/g) and roridin E (49.62ng/g) were found at a temperature of 26-30°C and a CO2 level of 1550-1650mg/m3. Rises in temperature as well as in temperature and CO2 concentrations had a significant effect by increasing Myrothecium leaf spots on spinach. The biosynthesis of verrucarin A was significantly increased at the highest temperature (35°C), while roridin E was influenced by the CO2 concentration. These results show that a positive correlation between climate condition and macrocyclic trichothecene production is possible. However, because of the ability of M. verrucaria to produce mycotoxins, an increase in temperature could induce the spread of M. verrucaria in temperate regions; this pathogen may gain importance in the future.

Extending the Shelf-Life of &amp;lt;i&amp;gt;Myrothecium verrucaria&amp;lt;/i&amp;gt;, a Bioherbicide

The shelf-life of a bioherbicide product is an important factor with regard to its commercial potential. The bioherbicidal efficacy of freshly fermented Myrothecium verrucaria (strain IMI 368023) (MV) mycelia formulations and MV mycelia preparations that had been freeze-dried and then stored at -20°C for 8 years was compared. Two concentrations of each formulation (1.0x and 0.5x) were tested, utilizing bioassays on seedlings of the weed, hemp sesbania (Sesbania exaltata) under greenhouse conditions or in darkness utilizing hydroponically grown seedlings. Freeze drying of freshly prepared MV mycelium produced a light, brownish-colored powder. Efficacy tests of this reconstituted 8-year-old dried material showed that some bioherbicidal activity was lost during long-term storage, i.e., ~20% and ~60% seedling dry weight reduction at the 1.0x and 0.5x rate, respectively. Although plant mortality was greater in the fresh mycelial preparations treatments versus the freeze-dried and stored samples at all time points in the time-course, the stored material still caused >80% mortality, 15 days after treatment. Comparative disease progression ratings also showed a similar trend. Overall results show that freeze-drying MV is a useful method to reduce the bulk and cumbersomeness of storing heavy liquid fermentation product, while retaining bioherbicidal activity. These findings increase the utility of this bioherbicide and offer the potential to use the dried material in soil treatments or in a more concentrated form than attainable via the fermented product.

Immobilization of Redox Enzymes on Nanoporous Gold Electrodes: Applications in Biofuel Cells.

Nanoporous gold (NPG) electrodes were prepared by dealloying sputtered gold:silver alloys. Electrodes of different thicknesses and pore sizes areas were prepared by varying the temperature and duration of the dealloying procedure; these were then used as supports for FAD-dependent glucose dehydrogenase (GDH) (Glomorella cingulata) and bilirubin oxidase (BOx) (Myrothecium verrucaria). Glucose dehydrogenase was immobilized by drop-casting a solution of the enzyme with an osmium redox polymer together with a crosslinked polymer, whereas bilirubin oxidase was attached covalently through carbodiimide coupling to a diazonium-modified NPG electrode. The stability of the bilirubin-oxidase-modified NPG electrode was significantly improved in comparison with that of a planar gold electrode. Enzyme fuel cells were also prepared; the optimal response was obtained with a BOx-modified NPG cathode (500 nm thickness) and a GDH-modified anode (300 nm), which generated power densities of 17.5 and 7.0 μW cm-2 in phosphate-buffered saline and artificial serum, respectively.

Контамінація та ушкодження мікроміцетами зерна та кормів

Контамінація та ушкодження мікроміцетами зерна та кормів

Dual gas-diffusion membrane- and mediatorless dihydrogen/air-breathing biofuel cell operating at room temperature

Abstract A membraneless direct electron transfer (DET)-type dihydrogen (H2)/air-breathing biofuel cell without any mediator was constructed wherein bilirubin oxidase from Myrothecium verrucaria (BOD) and membrane-bound [NiFe] hydrogenase from Desulfovibrio vulgaris Miyazaki F (MBH) were used as biocatalysts for the cathode and the anode, respectively, and Ketjen black-modified water proof carbon paper (KB/WPCC) was used as an electrode material. The KB/WPCC surface was modified with 2-aminobenzoic acid and p-phenylenediamine, respectively, to face the positively charged electron-accepting site of BOD and the negatively charged electron-donating site of MBH to the electrode surface. A gas-diffusion system was employed for the electrodes to realize high-speed substrate supply. As result, great improvement in the current density of O2 reduction with BOD and H2 reduction with MBH were realized at negatively and postively charged surfaces, respectively. Gas diffusion system also suppressed the oxidative inactivation of MBH at high electrode potentials. Finally, based on the improved bioanode and biocathode, a dual gas-diffusion membrane- and mediatorless H2/air-breathing biofuel cell was constructed. The maximum power density reached 6.1 mW cm−2 (at 0.72 V), and the open circuit voltage was 1.12 V using 1 atm of H2 gas as a fuel at room temperature and under passive and quiescent conditions.

Nanoporous Gold Electrodes with Tuneable Pore Sizes for Bioelectrochemical Applications

AbstractNanoporous gold (NPG) fabricated by sputtering is a material of versatile morphology with pores whose size can be tailored to accommodate enzymes. The process of pore formation and the size of the pores in NPG are influenced by the composition of Au and Ag in the alloy used to prepare the electrodes together with the temperature and time period of the dealloying process. On increasing the time from 1 to 60 min and the temperature from 0.5 °C to 60.5 °C in concentrated HNO3, significant increases in the average pore diameters from 4.4 to 78 nm were observed with simultaneous decreases in the roughness factor (Rf). The pores of NPG were fully addressable regardless of the diameter, with Rf increasing linearly up to an alloy thickness of 500 nm. The influence of the pore size on the bioelectrochemical response of redox proteins was evaluated using cytochrome c as a model system. The highest current densities of ca. 30 µA cm−2 were observed at cytochrome c modified NPG electrodes with an average pore size of ca. 10 nm. The pores in NPG were also tuned for the mediatorless immobilization of Myrothecium verrucaria bilirubin oxidase. High current densities of ca. 65 µA cm−2 were observed at MvBOD modified NPG electrodes prepared by dealloying at 0.5 °C for 5 min with an average pore size of 8 nm, which is too small to accommodate the enzyme into the pores, indicating that the response was from enzyme adsorbed on the electrode surface.

How the Intricate Interactions between Carbon Nanotubes and Two Bilirubin Oxidases Control Direct and Mediated O2 Reduction.

Due to the lack of a valid approach in the design of electrochemical interfaces modified with enzymes for efficient catalysis, many oxidoreductases are still not addressed by electrochemistry. We report in this work an in-depth study of the interactions between two different bilirubin oxidases, (from the fungus Myrothecium verrucaria and from the bacterium Bacillus pumilus), catalysts of oxygen reduction, and carbon nanotubes bearing various surface charges (pristine, carboxylic-, and pyrene-methylamine-functionalized). The surface charges and dipole moment of the enzymes as well as the surface state of the nanomaterials are characterized as a function of pH. An original electrochemical approach allows determination of the best interface for direct or mediated electron transfer processes as a function of enzyme, nanomaterial type, and adsorption conditions. We correlate these experimental results to theoric voltammetric curves. Such an integrative study suggests strategies for designing efficient bioelectrochemical interfaces toward the elaboration of biodevices such as enzymatic fuel cells for sustainable electricity production.

Osmium(II) Complexes Bearing Chelating N-Heterocyclic Carbene and Pyrene-Modified Ligands: Surface Electrochemistry and Electron Transfer Mediation of Oxygen Reduction by Multicopper Enzymes

We report the synthesis of original osmium(II) complexes bearing chelating N-heterocyclic (NHC) and bipyridine ligands. The pincer ligand 1,1′-dimethyl-3,3′-methylenediimidazole-2,2′-diylidene was used to tune the redox properties of osmium complexes. Bipyridine ligands modified with pyrene groups were chosen to study the electrosynthesis of OsII-NHC-based metallopolymers as well as the noncovalent immobilization of these complexes on carbon-nanotube (CNT) electrodes. Poly-[OsII-NHC] polypyrene polymer was electrogenerated on a GC electrode, whereas the pyrene-modified [OsII-NHC] could interact with the CNTs’ sidewalls through π–π interactions, allowing the immobilization of the NHC complexes at the surface of π-extended nanostructured electrodes. Furthermore, an OsII-NHC complex was studied in water, showing electron transfer mediation with multicopper enzymes. UV–visible and electrochemical experiments demonstrate that redox properties of the OsII-NHC complex provide sufficient driving force for electron transfer with bilirubin oxidase from Myrothecium verrucaria while achieving high potential electroenzymatic oxygen reduction at E = +0.45 V vs Ag/AgCl at pH 6.5.

A new quinolinone from freshwater lake-derived fungus Myrothecium verrucaria

One new quinolinone, 7-hydroxy-3-methoxyviridicatin (1), along with eight known compounds (2–9) was isolated from the fungus Myrothecium verrucaria, which was collected from lake water of Chenghai, Yunnan Province, China. Their structures were elucidated by detailed analysis of spectroscopic data and comparison with related known compounds. Compounds 1 and 2 exhibited weak antibacterial activity. To the best of our knowledge, this is the first report on quinolinones (1–4) as the secondary metabolites of M. verrucaria.

First Report of Leaf Spot of Spinach (Spinacia oleracea) Caused by Myrothecium verrucaria in Italy

HomePlant DiseaseVol. 100, No. 8First Report of Leaf Spot of Spinach (Spinacia oleracea) Caused by Myrothecium verrucaria in Italy PreviousNext DISEASE NOTES OPENOpen Access licenseFirst Report of Leaf Spot of Spinach (Spinacia oleracea) Caused by Myrothecium verrucaria in ItalyA. Garibaldi, G. Gilardi, S. Franco-Ortega, and M. L. GullinoA. GaribaldiSearch for more papers by this author, G. GilardiSearch for more papers by this author, S. Franco-OrtegaSearch for more papers by this author, and M. L. GullinoSearch for more papers by this authorAffiliationsAuthors and Affiliations A. Garibaldi G. Gilardi S. Franco-Ortega M. L. Gullino , Centre of Competence for the Agro-Environmental Sector (AGROINNOVA) and DISAFA, Largo P. Braccini 2, 10095 Grugliasco, Italy. Published Online:24 May 2016https://doi.org/10.1094/PDIS-01-16-0012-PDNAboutSections ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat During the spring of 2015, plants of spinach (Spinacia oleracea L.) ‘Donkey’ were grown using conventional control strategies in plastic houses in the Lumbardy Region near Brescia (Northern Italy). The plants showed symptoms of a previously unknown foliar disease on 15- to 20-day-old plants that consisted of small, circular, sunken, gray-brown spots (1 to 2 mm in diameter) with a well-defined border. As the lesions expanded (up to 30 mm in diameter) they developed concentric rings, coalesced, and then the affected tissues became water-soaked. Creamy to black sporodochia appeared on the affected leaves. Roots were asymptomatic. Five hectares of plastic houses irrigated with well water by overhead sprinklers were affected, with 5 to 10% of plants exhibiting symptoms. Affected plants showed 30 to 60% incidence of diseased leaves. Isolations were carried out on symptomatic leaf-tissue sections (each 1 mm2) dipped in 1% sodium hypochlorite for 1 min, rinsed in sterilized water, dried on sterilized filter paper, and then placed on potato dextrose agar (PDA) amended with 25 mg/liter of streptomycin sulfate. A white slow-growing fungus was obtained that developed black sporodochia 7 to 10 days after plating, similar to those present on the affected leaves. Conidia were cylindrical, nonseptate, without appendages, measuring 5.8 to 9.2 and 1.9 to 2.8 (avg. of 30 conidia, 7.6 ± 1.14 × 2.4 ± 0.22) µm. The morphological characteristics of the isolated pathogen corresponded to those of Myrothecium spp. (Domsch et al. 1980). The Internal Transcribed Spacer (ITS) region of rDNA was amplified using the primers ITS1/ITS4 and sequenced. BLAST analysis (Altschul et al. 1997) of the 516-bp segment showed a 100% similarity with M. verrucaria KR708633.1. A GenBank Accession No. KT354922 was assigned. To confirm pathogenicity, 15-day-old leaf spinach plants cv. Donkey were transplanted in 2-liter pots, filled with a steamed peat, perlite, and sand substrate in a ratio of 60:20:20 vol/vol and maintained in a growth chamber between 20 and 24°C. Five pots per treatment were used with five plants per pot. The artificial inoculation was carried out by spraying leaves with a spore suspension (1 × 105 conidia/ml) prepared from 15-day-old PDA cultures of one representative isolate of the pathogen grown under 12 h of photoperiod at 20°C. Control plants were inoculated with distilled water. Plants were kept covered with plastic bags for 5 days. Spots similar to those of the original plants developed 7 days after the inoculation, with a disease incidence ranging from 60 to 70% of the plants affected. All the noninoculated plants remained asymptomatic. A fungus morphologically identified as M. verrucaria was consistently isolated from all the symptomatic plants. The pathogenicity test was conducted twice, showing the same results. This is the first report of M. verrucaria on S. oleracea in Italy as well as worldwide. The cultivation of spinach for the fresh market is increasing in recent years in northern Italy. Currently, this disease has spread to several farms in the Lumbardy Region, causing limited crop losses.

Efficiency of Enzymatic O2 Reduction by Myrothecium verrucaria Bilirubin Oxidase Probed by Surface Plasmon Resonance, PMIRRAS, and Electrochemistry

Deciphering which parameters control the immobilization of enzymes on solid supports is essential for the development of biotechnological devices such as biosensors, bioreactors, and enzymatic fuel cells. In this work, we used surface plasmon resonance (SPR) coupled with electrochemistry and polarization modulated infrared reflection absorption spectroscopy (PMIRRAS) to correlate the loading, the conformation, and the activity of Myrothecium verrucaria bilirubin oxidase (Mv BOD) enzymes immobilized on two oppositely charged self-assembled monolayers (SAMs) on gold electrodes. The SPR signal showed that an enzyme layer close to a monolayer was formed by spontaneous adsorption on both negatively and positively charged SAMs. A different catalytic process for O2 reduction was obtained, however, being a direct catalysis at negative interfaces and a mediated catalysis at positive interfaces, in relation to the charge of the amino acids surrounding the surface of the Cu T1 and the dipole moment direction of Mv B...

Control biológico In Vitro de nematodos agalladores (Meloidogyne sp.) a base de quitosano y fluensulfone

El nematodo agallador (Meloidogyne sp.) tiene importancia económica potencial en diversos cultivos, en su combate casi siempre se han utilizado diferentes productos de agroquímicos, por lo que se necesita evaluar nuevos productos que sean una mejor alternativa en su manejo y en el cuidado al medio ambiente. En el presente trabajo se evaluó la eficacia biológica de diferentes extractos del quitosano un biopolímero natural con efecto nematicida y regulador de poblaciones de estos fitonematodos y Fluensulfone un nematicida de amplio espectro, el estudio se realizó In vitro, se colectaron muestras de suelo y se extrajeron los nematodos mediante el método de embudo de Baermann, se colocaron en cajas petri en diluciones con 30-35 nematodos por unidad experimental, en donde para su control se utilizó quitosano extraído de langostino de rio y quitosano comercial a diferentes concentraciones (0. 25, 0.50, 0.75), así mismo un nematicida comercial con extracto de quitosano Nematrol Plus , esto comparado con otros nematicidas comerciales Ditera (Myrothecium verrucaria ), Nemover (Extracto de pino) y Nimitz (Fluensulfone) .Se encontró que el efecto nematicida del quitosano en dosis media (0.50) fue mejor posterior a las 24 horas después de la aplicación con una mortalidad de 95.83 a 100 % de nematodos, y una eficacia del 100 %, esto comparado con los nematicidas comerciales.

Rapid kudzu eradication and switchgrass establishment through herbicide, bioherbicide and integrated programmes

ABSTRACTAmong the most important and visible weeds in the Southeastern USA is the exotic invasive vine, kudzu (Pueraria montana var. lobata). Efforts to eradicate it typically involve many years of application of restricted-use pesticides. Recent availability of effective, non-restricted-use pesticides and developments with the application of the bioherbicide Myrothecium verrucaria has made possible new control programmes for kudzu management. Field trials at three sites over two years with aminocyclopyrachlor, aminopyralid, fluroxypyr, metsulfuron methyl and combinations of these herbicides achieved 99–100% reduction in aboveground kudzu biomass. Additionally, programmes were developed that eradicated kudzu while simultaneously establishing native vegetation. One of these successful programmes integrated bioherbicide application, mechanical removal of kudzu biomass and planting switchgrass (Panicum virgatum) in an entirely chemical herbicide-free system. These field tests demonstrate a variety of methods that can be used independently or in an integrated approach for rapid kudzu eradication.