Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.10.3.2 (laccase)
4,656 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Effect of various cultivation conditions and lignin preparations on the enzymes of ligninolytic enzyme complex of white-rot fungus Pleurotus floridae has been studied. The maximal Mn-peroxidase activity was revealed in the medium with low nitrogen content (1.2 mM); maximal values of cellobiose quinone oxidoreductase activity were observed in the media with high nitrogen content (7.2 mM); maximal values of laccase activity in the media with low content of glucose (2 g/l) during Pleurotus floridae cultivation in Kirk's stationary cultures have been shown. Employment of submerged cultivation under conditions of mycelium immobilization on polyurethane carriers allowed us to increase laccase activity twice as compared with cultivation in small stationary cultures, while had the crucial effect on the Mn-peroxidase activity. The selective effect of the studied lignin preparations on the components of ligninolytic complex and their isoenzymes has been stated. The dependence of laccase and Mn-peroxidase activities on high and low-molecular weight fractions balance in lignin preparations has been established.
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PMID:[Effect of lignin preparations and cultivation conditions on the ligninolytic complex of the fungus Pleurotus floridae, the wood white-rot pathogen]. 945 73

Fourteen strains of white-rot basidiomycetes belonging to eight species of two genera (Inonotus and Pholiota) were tested for their ability to maintain the production of laccase, peroxidase and manganese-dependent peroxidase (enzymes involved in lignin biodegradation) after a short-time preservation in liquid nitrogen with different cryoprotectives (glycerol, dimethyl sulfoxide). No negative effect of cryopreservation or the used cryoprotective on production of the ligninolytic enzymes was found in the fungi tested.
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PMID:Activities of ligninolytic enzymes in some white-rot basidiomycete strains after recovering from cryopreservation in liquid nitrogen. 980 64

A basidiomycetous fungus Flavodon flavus (Klotzsch) Ryvarden (strain 312), isolated from decaying sea grass from a coral lagoon off the west coast of India, mineralized nearly 24% of 14C-labeled synthetic lignin to 14CO2 in 24 days. When grown in low-nitrogen medium (2.4 mM N) this fungus produced three major classes of extracellular lignin-modifying enzymes (LMEs): manganese-dependent peroxidase (MNP), lignin peroxidase (LIP), and laccase. Low MNP and laccase activities were seen in high-nitrogen medium (24 mM N), but no LIP activity was seen. In media containing lignocellulosic substrates such as pine, poplar, or sugarcane bagasse as the sole source of carbon and nitrogen, relatively high MNP and moderate levels of laccases were seen, but LIP production either was not seen or was minimal. LME production was also seen in media prepared with artificial seawater. Fast protein liquid chromatography and isoelectric focusing resolved LMEs into four isozymes each of MNP and LIP, while laccase isozymes were resolved into two groups, one group containing seven isozymes (pIs 4 to 6) and the other group containing at least three isozymes (pIs < 3). The molecular masses of the different isozymes were 43 to 99 kDa for MNP, 40 and 41.5 kDa for LIP, and 43 and 99 kDa for laccase. F. flavus showed effective degradation of various dye pollutants in media prepared with or without artificial seawater. This is the first report on the production of all three major classes of LMEs by F. flavus and points to the bioremediation potential of this organism in terrestrial as well as marine environments.
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PMID:Lignin-modifying enzymes of flavodon flavus, a basidiomycete isolated from a coastal marine environment 1022 7

Wheat straw cultures of the brown rot fungi Gloeophyllum striatum and G. trabeum degraded 2,4-dichlorophenol and pentachorophenol. Up to 54% and 27% 14CO2, respectively, were liberated from uniformly 14C-labeled substrates within 6 weeks. Under identical conditions Trametes versicolor, a typical white rot species employed as reference, evolved up to 42% and 43% 14CO2 and expressed high activities of laccase, manganese peroxidase, and manganese-independent peroxidase. No such activity could be detected in straw or liquid cultures of Gloeophyllum. Moreover, G. striatum degraded both chlorophenols most efficiently under non-cometabolic conditions, i.e. on a defined mineral medium lacking sources of carbon, nitrogen and phosphate.
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PMID:Degradation of 2,4-dichlorophenol and pentachlorophenol by two brown rot fungi. 1036 17

Production of ligninolytic enzymes and degradation of 14C-ring labeled synthetic lignin by the white-rot fungus Cyathus stercoreus ATCC 36910 were determined under a variety of conditions. The highest mineralization rate for 14C dehydrogenative polymerizates (DHP; 38% 14CO2 after 30 days) occurred with 1 mM ammonium tartrate as nitrogen source and 1% glucose as additional carbon source, but levels of extracellular laccase and manganese peroxidase (MnP) were low. In contrast, 10 mM ammonium tartrate with 1% glucose gave low mineralization rates (10% 14CO2 after 30 days) but higher levels of laccase and manganese peroxidase. Lignin peroxidase was not produced by C. stercoreus under any of the studied conditions. Mn(II) at 11 ppm gave a higher rate of 14C DHP mineralization than 0.3 or 40 ppm, but the highest manganese peroxidase level was obtained with Mn(II) at 40 ppm. Cultivation in aerated static flasks gave rise to higher levels of both laccase and manganese peroxidase compared to the levels in shake cultures. 3,4-Dimethoxycinnamic acid at 500 microM concentration was the most effective inducer of laccase of those tested. The purified laccase was a monomeric glycoprotein having an apparent molecular mass of 70 kDa, as determined by calibrated gel filtration chromatography. The pH optimum and isoelectric point of the purified laccase were 4.8 and 3.5, respectively. The N-terminal amino acid sequence of C. stercoreus laccase showed close homology to the N-terminal sequences determined from other basidiomycete laccases. Information on C. stercoreus, whose habitat and physiological requirements for lignin degradation differ from many other white-rot fungi, expands the possibilities for industrial application of biological systems for lignin degradation and removal in biopulping and biobleaching processes.
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PMID:Production of ligninolytic enzymes and synthetic lignin mineralization by the bird's nest fungus Cyathus stercoreus. 1057 Aug 16

Ganoderma lucidum, a white rot basidiomycete widely distributed worldwide, was studied for the production of the lignin-modifying enzymes laccase, manganese-dependent peroxidase (MnP), and lignin peroxidase (LiP). Laccase levels observed in high-nitrogen (HN; 24 mM N) shaken cultures were much greater than those seen in low-nitrogen (2.4 mM N), malt extract, or wood-grown cultures and those reported for most other white rot fungi to date. Laccase production was readily seen in cultures grown with pine or poplar (100-mesh-size ground wood) as the sole carbon and energy source. Cultures containing both pine and poplar showed 5- to 10-fold-higher levels of laccase than cultures containing pine or poplar alone. Since syringyl units are structural components important in poplar lignin and other hardwoods but much less so in pine lignin and other softwoods, pine cultures were supplemented with syringic acid, and this resulted in laccase levels comparable to those seen in pine-plus-poplar cultures. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of concentrated extracellular culture fluid from HN cultures showed two laccase activity bands (M(r) of 40,000 and 66, 000), whereas isoelectric focusing revealed five major laccase activity bands with estimated pIs of 3.0, 4.25, 4.5, 4.8, and 5.1. Low levels of MnP activity ( approximately 100 U/liter) were detected in poplar-grown cultures but not in cultures grown with pine, with pine plus syringic acid, or in HN medium. No LiP activity was seen in any of the media tested; however, probing the genomic DNA with the LiP cDNA (CLG4) from the white rot fungus Phanerochaete chrysosporium showed distinct hybridization bands suggesting the presence of lip-like sequences in G. lucidum.
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PMID:Lignin-modifying enzymes of the white rot basidiomycete Ganoderma lucidum. 1058 81

In the present study we investigated the possibility of proteinases, intracellular and extracellular, being involved in the regulation of ligninolytic activities in cultures of Trametes versicolor during the shift from primary growth (i.e. trophophase) to idiophase triggered by nitrogen or carbon starvation. These studies were performed using specific inhibitors added to the cultures of T. versicolor. Addition of PMSF (irreversible inhibitor of serine proteinases) or chloroquine (the lysosomotropic agent inhibiting intralysosomal degradation of proteins) revealed distinct differences in the activity of ligninolytic enzymes between nutrient-deprived and non-starved cultures. The addition of PMSF during the transfer of mycelia to the nutrient limited media significantly enhanced the activities of laccase (2-7-fold) and of unspecified peroxidases (2-4-fold). The activity of lignin peroxidase decreased with PMSF, both in tropho- and in idiophasic cultures. The enhanced activities of laccase and general peroxidases (horseradish peroxidase-like, HRP-like) were accompanied by markedly altered patterns of both intracellular and extracellular proteolytic activities revealed by electrophoretic analysis with polyacrylamide gels containing the copolymerized substrate (haemoglobin or gelatin, respectively). The experiments with chloroquine added to nutrient-deprived cultures showed that inhibition of vacuolar proteolysis resulted in lowered activities of laccase and peroxidase. Electrophoretic analysis revealed altered patterns of intracellular proteinases upon chloroquine addition to nutrient-starved cultures. Moreover, chloroquine was found to enhance the activity of proteases secreted in carbon-starved cultures. From the results it is concluded that both intracellular (including vacuolar) and extracellular proteases are involved in the regulation of laccase and peroxidase activity in cultures of T. versicolor under nutrient limitation.
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PMID:Studies on the role of proteases in the white-rot fungus Trametes versicolor: effect of PMSF and chloroquine on ligninolytic enzymes activity. 1074 99

Growth parameters, ligninolytic enzyme activities and ability to degrade polycyclic aromatic hydrocarbons by the fungus Irpex lacteus were characterized and compared with those of other white rot fungi capable of rapid decolorization of poly R-478 and Remazol Brilliant Blue R dyes. I. lacteus was able to grow on mineral and complex media and efficiently colonized sterile and non-sterile soil by exploratory mycelium growing from a wheat straw inoculum. In shallow stationary cultures growing on high nitrogen mineral medium containing 45 mM ammonium as nitrogen source, the fungus produced lignin peroxidase (LIP), Mn-dependent peroxidase (MnP) and laccase simultaneously, the respective maximal activities of 70, 970 and 36 U/l being attained around day 18. Growing in nitrogen-limited medium (2.4 mM ammonium), no LIP was formed and levels of MnP and laccase decreased significantly. During growth in sterile soil, the fungus synthesized LIP and laccase but not MnP. I. lacteus efficiently removed three- and four-ringed PAHs from liquid media and artificially spiked soil. The variety of ligninolytic enzymes, robust growth, capability of soil colonization and resistance to inhibitory action of soil bacteria make I. lacteus a suitable fungal organism for use in bioremediation.
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PMID:Irpex lacteus, a white rot fungus applicable to water and soil bioremediation. 1115 80

Flavodon flavus (Klotzsch) Ryvarden, a basidiomycete (NIOCC strain 312) isolated from decomposing leaves of a sea grass, decolorized pigments in molasses spent wash (MSW) by 80% after 8 days of incubation, when used at concentrations of 10% and 50%. Decolorizing activity was also present in media prepared with half-strength seawater (equivalent to 15 ppt salinity). Decolorizing activity was seen in low-nitrogen medium, nutrient-rich medium and in sugarcane bagasse medium. The percentage decolorization of MSW was highest when glucose or sucrose was used as the carbon source in the low-nitrogen medium. The production of lignin-modifying enzymes, manganese-dependent peroxidase (MNP) and laccase decreased in a medium containing MSW. MNP production and MSW decolorization were inversely correlated, suggesting no role for MNP in MSW decolorization. The decolorization of MSW was not effective when F. flavus was immobilized in calcium alginate beads. Decolorization was achieved best in oxygenated cultures. Besides color, total phenolics and chemical oxygen demand were reduced by 50% in MSW treated with F. flavus, suggesting its potential in the bioremediation of effluents.
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PMID:Decolorization of molasses spent wash by the white-rot fungus Flavodon flavus, isolated from a marine habitat. 1139 35

Four laccase isozyme genes, Psc lac1, 2, 3 and 4 have been cloned from the edible mushroom, Pleurotus sajor-caju. The genes display a high degree of homology with other basidiomycete laccases (55-99%) at the amino acid level. Of the laccase genes isolated, Psc lac1 and 4 displayed the highest degree of similarity (85% at the amino acid level), while Psc lac3 showed the highest degree of divergence, exhibiting only 52-57% amino acid similarity to the other PL: sajor-caju laccase gene sequences. Laccase activity in PL: sajor-caju is affected by nutrient nitrogen and carbon, and by the addition of copper and manganese to the growth medium. In addition, 2,5-xylidine, ferulic acid, veratric acid and 1-hydroxybenzotriazole induced laccase activity in the fungus. Induction of individual laccase isozyme genes by carbon, nitrogen, copper, manganese and the two aromatic compounds, 2,5-xylidine and ferulic acid, occurred at the level of gene transcription. While Psc lac3 transcript levels appeared to be constitutively expressed, transcript levels for the other laccase isozyme genes, lac1, 2 and 4, were differentially regulated under the conditions tested.
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PMID:Differential regulation of laccase gene expression in Pleurotus sajor-caju. 1142 53


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