Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino Moscow region. leont@ibpm.serpukhov.su
Abstract
The toxicity of thirteen isomers of mono-, di-, tri- and pentachlorophenols was tested in potato-dextrose agar cultures of the white rot fungi Panus tigrinus and Coriolus versicolor. 2,4,6-Trichlorophenol (2,4,6-TCP) was chosen for further study of its toxicity and transformation in liquid cultures of these fungi. Two schemes of 2,4,6-TCP addition were tested to minimize its toxic effect to fungal cultures: stepwise addition from the moment of inoculation and single addition after five days of growth. In both cases the ligninolytic enzyme systems of both fungi were found to be responsible for 2,4,6-TCP transformation. 2,6-Dichloro-1,4-hydroquinol and 2,6-dichloro-1,4-benzoquinone were found as products of primary oxidation of 2,4,6-TCP by intact fungal cultures and purified ligninolytic enzymes, Mn-peroxidases and laccases of both fungi. However, primary attack of 2,4,6-TCP in P. tigrinus culture was conducted mainly by Mn-peroxidase, while in C. versicolor it was catalyzed predominantly by laccase, suggesting a different mode of regulation of these enzymes in the two fungi.
Department of Science, Faculty of Education, Inonu University, 44069 Malatya, Turkey. sskahraman@inonu.edu.tr
Abstract
White-rot fungi, Coriolus versicolor and Funalia trogii, produced laccase on media with diluted olive-oil mill wastewater and vinasse. Addition of spent cotton stalks enhanced the laccase activity with a maximum after 12 d of cultivation.
Department of Biology, Science Faculty, Hacettepe University, Ankara, Turkey.
Abstract
Agitation, temperature, inoculum size, initial pH and pH of buffered medium affected the decolorization of Orange II dye by Coriolus versicolor and Funalia trogii. The optimum temperature and initial pH value for decolorization were 30 degrees C and 6.5-7.0, respectively; pH 4.5 was the most efficient in buffered cultures. High decolorization extents were reached at all agitation rates. At an inoculum size of more than 1 mL, the extent of decolorization changed only slightly. High extents were obtained using immobilized fungi at repeated batch mode.
Laboratoire d’Etudes et de Recherches sur le Matériau Bois, UMR INRA 1093, Equipe de Chimie Organique et Microbiologie, Université Henri Poincaré, Nancy I, Faculté des Sciences, BP 239, 54506 Vandoeuvre-lès-Nancy, France.
Abstract
The fungicidal activity of analogues of beta-thujaplicin, a natural product responsible for the durability of heartwood of several cupressaceous trees, was investigated in vitro on the growth of different white and brown rot fungi involved in wood biodegradation, Coriolus versicolor, Phanerochaete chrysosporium, Poria placenta and Gloephyllum trabeum. The study shows that 2-hydroxycyclohepta-2,4,6-trienone (tropolone), easily prepared according to a literature procedure, possesses interesting fungicidal activity when compared to beta-thujaplicin, azaconazole, tebuconazole and copper oxine, which suggests this compound should be examined further as a potential biocide for wood preservation.
Departamento de Biología Aplicada, CITE II-B, Universidad de Almeria, La Cañada de San Urbano, Spain. mllopez@ual.es
Abstract
The mineralisation and the humification of organic matter (OM) in sterile horticultural plant wastes inoculated with Coriolus versicolor or Phanerochaete flavido-alba was investigated under different aeration rates in order to determine their efficacy as potential inoculants for composting. The change in elemental composition, lignin content and OM fractions was analysed during a 90-day incubation. Both fungi degraded 30% of lignin at low aeration rates. Different aeration rates led to significant changes in OM mineralisation induced by C. versicolor, but did not have noticeable effect on P. flavido-alba activity. The mineralisation was more effectively carried out by P. flavido-alba than by C. versicolor. Lignin degradation and the linked humification process were equally achieved by the two fungi and were enhanced in aerated conditions. The fungi analysed may facilitate the composting of lignocellulosic wastes by means of an increase in substrate bioavailability and OM humification.
Faculty of Agriculture, Kyushu University, Fukuoka, Japan.
Abstract
The fungal conversions of sulfur-containing heterocyclic compounds were investigated using the lignin-degrading basidiomycete Coriolus versicolor. The fungus metabolized a series of sulfur compounds–25 structurally related thiophene derivatives–via several different pathways. Under primary metabolic conditions, C. versicolor utilized thiophenes, such as 2-hydroxymethyl-, 2-formyl-, and 2-carboxyl-thiophenes, as a nutrient sulfur source for growth; thus, the fungus degraded these compounds more effectively in a non-sulfur-containing medium than in conventional medium. The product analysis revealed that several redox reactions, decarboxylation reactions, and C-S cleavage reactions were involved in the fungal conversion of non-aromatic thiophenes. On the other hand, benzothiophene (BT) and dibenzothiophene (DBT) skeletons were converted to water-soluble products. All the products and metabolic intermediates were more hydrophilic than the starting substrates. These metabolic actions seemed to be a chemical stress response against exogenously added xenobiotics. These metabolic reactions were optimized under ligninolytic conditions, also suggesting the occurrence of a fungal xenobiotic response. Furthermore, the fungus converted a series of BTs and DBTs via several different pathways, which seemed to be controlled by the chemical structure of the substrates. DBT, 4-methylDBT, 4, 6-dimethylDBT, 2-methylBT, and 7-methylBT were immediately oxidized to their S-oxides. BTs and DBTs with the hydroxymethyl substituent were converted to their xylosides without S-oxidation. Those with carboxyl and formyl substituents were reduced to form a hydroxymethyl group, then xylosidated. These observations strongly suggested the involvement of a fungal substrate-recognition and metabolic response mechanism in the metabolism of sulfur-containing heterocyclic compounds by C. versicolor.
Department of Science, Faculty of Education, Inonu University, Malatya, Turkey. sskahraman@inonu.edu.tr
Abstract
Laccase is among the major enzymes of white rot fungi involved in lignocellulose degradation. The present paper reports its production by two white rot fungi (Coriolus versicolor, Funalia trogii) under different nutritional conditions. Various synthetic culture media and natural culture medium (molasses wastewater) were tested. Enzyme production in various synthetic culture media, molasses wastewater (vinasse) culture medium and in the absence or presence of cotton stalk supplements showed that vinasse culture medium was a better laccase-inducer medium than the synthetic culture medium. Addition of cotton stalk to various media enhanced the enzyme production. The highest laccase activity was obtained in vinasse culture medium with cotton stalk.
School of Biological & Chemical Sciences, Birkbeck College, University of London, United Kingdom.
Abstract
Adult females of Xestobium rufovillosum de Geer demonstrated anemotactic orientation when exposed to an odor plume containing volatiles generated by wood-decaying fungi (Coriolus versicolor, Donkioporia expansa) and decayed oak wood (Quercus petraea, Quercus robur). They did not orient towards undecayed oak wood, beech (Fagus sylvatica), or pine wood (Pinus sylvestris). Although all insects tested showed anemotactic orientation, responses were nonlinear with respect to insect age. Adult females more readily oriented upwind when they were between 10 and 16 days old. Oviposition choice bioassays showed that ovipositing females would preferentially oviposit on extract-treated cellulose paper discs that had been treated with various strains of the wood-decaying fungus, Donkioporia expansa. HPLC-fractionated mycelial extracts were attractive to ovipositing deathwatch beetles, whereas HPLC-fractionated fungal broth extracts were repellent to ovipositing females. The implications of these results are discussed in the context of timber pest management in historically important buildings.
Laboratory for Molecular Pharmacology, Department of Hygiology, First Military Medical University, Guangzhou 510515, China. songlc@fimmu.edu.cn
Abstract
AIM: To investigate the effect of Coriolus versicolor polysaccharide B (CVPS-B), a new water-soluble component of polysaccharides from the fungus Coriolus versicolor (Fr) L on monocyte chemoattractant protein-1 (MCP-1) gene expression in rat splenocytes.
METHODS: Expression of MCP-1 mRNA in rat splenocytes was examined by reverse transcription-polymerase chain reaction (RT-PCR) with beta- actin as an internal standard. Sequencing of RT-PCR products was performed to confirm their specificity in MCP-1 gene composition.
RESULTS: (1) Without pre-treatment of lipopolysaccharide (LPS), the relative MCP-1 mRNA expression ratios (MCP-1/beta-actin) for the saline control group and for CVPS-B groups in 3 different doses (10, 20, and 30 mg . kg-1 . d-1, ip, for 4 d) were 1.4 +/- 0.3, 1.6 +/- 0.4, 1.7 +/- 0.5, and 1.5 +/- 0.4, respectively (P > 0.05); (2) LPS (10 microg . kg-1, ip) enhanced the expression of MPC-1 mRNA by the ratio of 114 %; (3) pre-treatment with CVPS-B of 4 different doses (5, 10, 30, and 50 mg . kg-1 . d-1, ip, for 4 d) decreased the LPS induced expression of MPC-1 mRNA by the ratios of 51 %, 70 %, 84 %, and 99 %, respectively (n = 6).
CONCLUSION: In a dose-related fashion, CVPS-B inhibited the expression of MCP-1 mRNA induced by LPS in the rat splenocytes, but did not significantly affect the expression of MPC-1 mRNA in the normal rat.
Horticulture Research International, Wellesbourne, Warwick CV35 9EF, UK. gary.bending@hri.ac.uk
Abstract
The capacity of nine species of white rot fungus from a variety of basidiomycete orders to degrade contrasting mono-aromatic pesticides was investigated. There was no relationship between degradation of the dye Poly R-478, a presumptive test for ligninolytic potential, and degradation of the highly available pesticides diuron, metalaxyl, atrazine or terbuthylazine in liquid culture. However, there were significant positive correlations between the rates of degradation of the different pesticides. Greatest degradation of all the pesticides was achieved by Coriolus versicolor, Hypholoma fasciculare and Stereum hirsutum. After 42 days, maximum degradation of diuron, atrazine and terbuthylazine was above 86%, but for metalaxyl less than 44%. When grown in the organic matrix of an on-farm “biobed” pesticide remediation system, relative degradation rates of the highly available pesticides by C. versicolor, H. fasciculare and S. hirsutum showed some differences to those in liquid culture. While H. fasciculare and C. versicolor were able to degrade about a third of the poorly available compound chlorpyrifos in biobed matrix after 42 days, S. hirsutum, which was the most effective degrader of the available pesticides, showed little capacity to degrade the compound.