Biodegradação de fenol por uma nova linhagem de A spergillus sp. isolada de um solo contaminado do sul do Brasil

The main goal of this work was to study the biodegradation of phenol in batch mode by a filamentous fungus isolated from a contaminated site in Southern Brazil. A better performance was obtained by previous adaptation of the microorganism to the toxic chemical. A 2³ experimental design was proposed and it could be observed total phenol degradation in 72 h using 500 mg L-1 glucose, inoculum of 20% and agitation of 200 rpm, resulting a biodegradation rate of 3.76 mg L-1 h-1. In relation to phenol tolerance, Aspergillus sp. LEBM2 was able to consume up to 989 ± 15 mg L-1.

Esteroides produzidos por Penicillium herquei, um fungo endofítico isolado dos frutos de Melia azedarach (Meliaceae)

Six compounds comprising the groups of steroids, the ergosterol, the ergosterol peroxide, the cerevisterol, the neociclocitrinols, the ergosta-4,6,8(14),22-tetraen-3-one, the 25-hydroxy-ergosta-4,6,8(14),22-tetraen-3-one, were isolated from Penicillium herquei fungus obtained from Melia azedarach. The structures were identified by spectral methods of RMN 1D and 2D and MS.

Uma visão sobre a estrutura, composição e biodegradação da madeira

Wood is the main raw material used in the pulp and paper industry. It is a material that presents heterogeneous structure and complex composition, which results in a relatively resistant material to the biodegradation process. In the present review, we attempted to summarize the structural characteristics of wood and describe the chemical nature of its major components to, afterwards, comment about its biodegradation. The role of the enzyme manganese peroxidase in the lignin degradation by a selective white-rot fungus, Ceriporiopsis subvermispora, was highlighted.

Antifungal iridoids, triterpenes and phenol compounds from Alibertia myrciifolia Sprunge Ex. Schum

The new iridoid glucoside 10-O-vanilloyl-geniposidic acid has been isolated from the aerial parts of Alibertia myrciifolia along with hydroxyhopanone, 3α,22-dihydroxyhopane, ursolic acid, luteolin-3´,4´-dimethyl ether, caffeic acid and geniposidic acid. The structures of the isolated compounds were determined by means of mass spectrometry and nuclear magnetic resonance spectral analyses. The antifungal activities of the iridoids 10-O-vanilloyl-geniposidic acid and geniposidic acid were evaluated against the phytopathogenic fungi strains Colletotrichum gloeosporioides, Fusarium solani and Aspergillus niger.

Citocalasinas produzidas por Xylaria sp., um fungo endofítico de Piper aduncum (piperaceae)

A chemical study on the EtOAc extract produced by Xylaria sp., an endophytic fungus from Piper aduncum, resulted in the isolation of a new cytochalasin 1, along with five known 19,20-epoxycytochalasin D (2), C (3), N (4), Q (5), and R (6). The 1-6 were evaluated against the fungi C. cladosporioides and C. sphaerospermum and only 5 showed weak activity. The cytotoxicity in vitro against HeLA and CHO cells lines were investigated and the cytochalasins 2-4, and 6 showed a strong activity against HeLA. The DNAdamaging activity of 1-6 were also investigated against mutant strains of S. cerevisiae.

Removal of high-molecular weight polycyclic aromatic hydrocarbons

Alternatives for the removal of high-molecular weight polycyclic aromatic hydrocarbons (HWM-PAH) from soil were tested by adding fertilizer or glycerol, as well as the combination of both. Experiments were carried out for 60 days in reactors containing a HWM-PAH-contaminated soil (8030 μg kg-1), accompanied by pH monitoring, humidity control and quantification of total heterotrophic bacteria and total fungus. Fertilizer addition removed 41.6% of HWM-PAH. Fertilizer and glycerol in combination removed 46.2%. When glycerol was added individually, degradation reached 50.4%. Glycerol also promoted the increase of degradation rate during the first 30 days suggesting the HMW-PAH removal occurred through cometabolic pathways.

Biodegradação de uma mistura de corantes têxteis usando o fungo Ganoderma sp: um estudo cinético

The kinetics of biodegradation by the fungus Ganoderma sp of textile dyes Yellow, Blue and Red Procion were studied in effluents using UV-Vis spectroscopy, Partial Least Squares Regression (PLS) and univariate analysis. The kinetic of the reactions were founded intermediate between first and second orders and the rate constants were calculated. The biodegradation after 72 h at 28 ºC were 33.6, 43.5 and 57.7% for the dyes Yellow, Blue and Red Procion, respectively. The quantitative analysis of the effluent by HPLC method can not be used without previous separation.

Pyrrolizidine alkaloids of senecio sp from Peru

Six pyrrolizidine alkaloids (PAs) (two saturated macrocyclic, three unsaturated macrocyclic and one unsaturated seco-macrocyclic) were isolated from native Peruvian Senecio species. The structures of these alkaloids were established by a complete NMR spectroscopic analysis, chemical transformations and comparison of their NMR data with those published for similar alkaloids. Three PAs were then tested for antifungal activity against Fusarium moniliforme, F. (Sheldon), F. oxysporum fs. lycopersici (Scheldt) and F. solani (Mart), no significant activity being observed.

Caracterización de la biomasa inactiva de Aspergillus niger O-5 como sorbente de Pb (II)

The inactive biomass of fungus Aspergillus niger O-5 obtained in Cuba was characterized as sorbent of Pb2+ by several structural analysis and others techniques. In addition, the biomass was studied for the separation / preconcentration of Pb2+ from aqueous solution. The maximum biosorption capacity was obtained for the contact time of 30 min and pH 5. The kinetic of sorption process occurred according to the model of Ho. The Freundlich or Langmuir models suitably described the experimental adsorption isotherms. The biomass can be used as sorbent for Pb2+ with a maximum capacity of 4.7 - 6.2 mg g-1. The pretreatment with NaOH solution improved its sorption capacity.

Synthesis and antifungal activity of halogenated aromatic bis-γ-lactones analogous to avenaciolide

Here we describe the total syntheses and characterization by elemental analyses, infrared and NMR spectroscopy of three new compounds analogous to avenaciolide, a bis-γ-lactone isolated from Aspergillus avenaceus that possesses antifungal activity, where the octyl group of the natural product was replaced by aromatic groups containing chlorine and fluorine atoms. The effects of the avenaciolide, the novel compounds and their synthetic precursors on mycelia development and conidia germination of Colletotrichum gloeosporioides and Fusarium solani were evaluated in vitro. The title compounds were almost as active as avenaciolide. The absolute structures of the chlorinated analogs were determined by X-ray diffraction analysis.

Uso de aditivos na biodegradação de madeira pelo fungo Ceriporiopsis subvermispora: efeito na peroxidação de lipídios dependente de manganês-peroxidase

Ceriporiopsis subvermispora is a selective fungus in the wood delignification and the most promising in biopulping. Through the lipid peroxidation initiated by manganese peroxidase (MnP), free radicals can be generated, which can act in the degradation of lignin nonphenolic structures. This work evaluated the prooxidant activity (based in lipid peroxidation) of enzymatic extracts from wood biodegradation by this fungus in cultures containing exogenous calcium, oxalic acid or soybean oil. It was observed that MnP significant activity is required to promote lipid peroxidation and wood delignification. Positive correlation between prooxidant activity x MnP was observed up to 300 IU kg-1 of wood.

Sesquiterpenos produzidos pelo fungo endofítico Phomopsis cassiae com atividade antifúngica e inibidora de acetilcolinesterase

SESQUITERPENES PRODUCED BY ENDOPHYTIC FUNGUS Phomopsis cassiae WITH ANTIFUNGAL AND ACETYLCHOLINESTERASE INHIBITION ACTIVITIES. Two new diastereoisomeric cadinanes sesquiterpenes 3,9-dihydroxycalamenene (1-2), along with the known 3-hydroxycalamen-8-one (3) and aristelegone-A (4), were isolated from ethyl acetate extract of Phomopsis cassiae, an endophytic fungus in Cassia spectabilis. Their structures, including relative stereochemistry, were determined on the basis of detailed interpretation of 2D NMR spectra and comparison with related known compounds. Compounds 1-4 displayed antifungal activity against the phytopathogenic fungi Cladosporium cladosporioides and C. sphaerospermum, as well as inhibition of acetylcholinesterase.

Phytotoxic effects of metabolites from Alternaria euphorbiicola against its host plant Euphorbia heterophylla

A bioassay-guided fractionation of culture filtrates of the fungus Alternaria euphorbiicola, a pathogen of the weed Euphorbia heterophylla, led to the isolation of anhydromevalonolactone (1), tyrosol (2), (R)-( - )-mevalonolactone (3), and cycloglycylproline (4). When tested on the punctured leaves of the host plant, these compounds produced bleached lesions with dark brown margins at concentrations as low as 80 µM. When tested on the leaves of other relevant weeds, only cycloglycylproline showed selective activity against E. heterophylla. This is the first report on the isolation of phytotoxins from A. euphorbiicola and on the phytotoxicity of anhydromevalonolactone, (R)-( - )-mevalonolactone, and cycloglycylproline.

Influência de parâmetros de processo na obtenção de sílica a partir de cinza da casca de arroz pela ação de Fusarium oxysporum

In this work, an experimental design was used to analyze the influence of process parameters on the production of extracellular enzymes such as β-glucosidase and peroxidase, and their possible effect on the obtention of soluble and nanostructured silica from rice husk ash by the action of the fungus Fusarium oxysporum. Specifically, pH, fermentation time and glucose concentration in the culture medium were varied. Statistical analysis indicated that the silica synthesis in the aqueous medium was strongly dependent on pH and time. Although the glucose concentration does not exert a direct influence on the biosynthesis of silica, it is an important parameter in the production of extracellular enzymes. To prevent enzyme inhibition and provide higher dissolution of silica, it is recommended to work at a pH close to neutral with a glucose concentration of 3 g L-1 for at least 144 h.

Development and validation of a RP-HPLC method to determine the xanthyletin content in biodegradable polymeric nanoparticles

Xanthyletin is used as an inhibitor of the symbiotic fungus (Leucoagaricus gongylophorus) of the leaf-cutting ant (Atta sexdens rubropilosa), one of the most significant agricultural plague insects. The incorporation of this compound into nanoparticles is a promising approach to effectively control leaf-cutting ants. This study presents the development and validation of a specific analytical method using high-performance liquid chromatography (HPLC) for quantification of the xanthyletin content in biodegradable polymeric nanoparticles. The analytical methodology developed was specific, linear, accurate, precise, and robust. The absolute recovery of xanthyletin in colloidal suspensions was nearly 100%. The HPLC method proved reliable for the quantification of xanthyletin content in nanoparticle formulations.