The extracellular ligninolytic enzyme system of Pleurotus laciniatocrenatus, grown under different culture conditions, was characterized and the ability of this strain to degrade different components of Eucalyptus globulus wood was determined. In shaken liquid cultures grown on a C-limited medium supplemented with yeast extract (0.1%) and peptone (0.5%), the fungus produced extracellular aryl-alcohol oxidase (Aao), laccase (Lac), manganese-dependent peroxidase (MnP) and manganese-independent peroxidase (MiP) activities, their maximum levels being, respectively, about 600, 50, 1360, and 920 pkat/mL. The supplementation of 1 mmol/L vanillic acid and 150 micromol/L CuSO4 produced an increase of Lac activity levels up to 4-fold and 68.3-fold, respectively. No significant differences were found in the levels of the other ligninolytic enzyme activities when compared to the basal medium. Solid-state fermentation cultures on E. globulus wood chips revealed Lac and MiP activities. These cultures showed degradative activity on lignin and lipophilic wood extractives.

• MeSH
• Biotechnology methods   MeSH
• Wood MeSH
• Eucalyptus metabolism   MeSH
• Culture Media MeSH
• Laccase metabolism   MeSH
• Lignin metabolism   MeSH
• Peroxidase metabolism   MeSH
• Pleurotus enzymology   growth & development   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Argentina MeSH
• Names of Substances
• Culture Media MeSH
• Laccase MeSH
• Lignin MeSH
• Peroxidase MeSH

The effect of enhanced laccase (Lac) activity (obtained after copper addition to cultivation media) on decolorization of azo dye Orange G in two basidiospore-derived monokaryotic isolates of Pleurotus ostreatus was determined. The high Lac-producing isolate efficiently decolorized Orange G. The low-producing isolate showed only poor decolorization ability during cultivation in liquid medium and no decolorization on agar plates containing Orange G after a 25-d growth. A substantial enhancement of Lac activity caused by copper addition into cultivation media was detected in both isolates but, at the same time, the biomass production decreased and decolorization rate was reduced.

• MeSH
• Enzyme Activation drug effects   MeSH
• Azo Compounds metabolism   MeSH
• Laccase metabolism   MeSH
• Environmental Pollutants metabolism   MeSH
• Copper pharmacology   MeSH
• Peroxidases metabolism   MeSH
• Pleurotus classification   enzymology   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Azo Compounds MeSH
• Laccase MeSH
• Environmental Pollutants MeSH
• manganese peroxidase MeSH Browser
• Copper MeSH
• Orange G MeSH Browser
• Peroxidases MeSH

The production of laccase in liquid cultures of the white-rot fungus Pleurotus ostreatus was highly variable. During the first days of cultivation, the relative variability was as high as 80-100% and it decreased to 30% in the course of cultivation. The main source of variability was assumed to be the independent development of enzyme activity in individual cultures. Cultures with high laccase production showed also high production of the other ligninolytic enzyme--Mn-dependent peroxidase. The variability was probably due to the source of inoculum, deactivation of the enzyme in culture liquid and genetic variations among the cultures. Variability of laccase activities was lower during solid-state fermentation on wheat straw and during the growth in nonsterile soil.

• MeSH
• Fermentation MeSH
• Culture Media MeSH
• Laccase MeSH
• Mycology methods   MeSH
• Oxidoreductases biosynthesis   metabolism   MeSH
• Pleurotus enzymology   growth & development   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Culture Media MeSH
• Laccase MeSH
• Oxidoreductases MeSH

The ability to decolorize four synthetic dyes (Phenol Red, Evans Blue, Eosin Yellowish and Poly B411) in five Pleurotus ostreatus strains (a parental strain and four isolates derived from it) was determined. Two of the isolates had markedly higher and other two substantially lower production of ligninolytic enzymes and hydrogen peroxide than the parental strain. Like the parental strain, the higher-producing isolates were able to decolorize all the tested dyes, but not to a higher extent than the parental strain. In contrast, two lower-producing isolates exhibited slow decolorization, which was incomplete even at the end of cultivation. Evans Blue and Eosin Yellowish strongly suppressed the growth of the strains, while Phenol Red and Poly B411 induced none or only a very slight growth reduction.

• MeSH
• Color MeSH
• Coloring Agents metabolism   MeSH
• Laccase MeSH
• Oxidoreductases metabolism   MeSH
• Hydrogen Peroxide metabolism   MeSH
• Peroxidases metabolism   MeSH
• Pleurotus chemistry   enzymology   metabolism   MeSH
• Textile Industry MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Coloring Agents MeSH
• Laccase MeSH
• manganese peroxidase MeSH Browser
• Oxidoreductases MeSH
• Hydrogen Peroxide MeSH
• Peroxidases MeSH

The white-rot fungus Pleurotus ostreatus was able to degrade the polycyclic aromatic hydrocarbons (PAHs) benzo[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, dibenzo[a,h]anthracene, and benzo[ghi]perylene in nonsterile soil both in the presence and in the absence of cadmium and mercury. During 15 weeks of incubation, recovery of individual compounds was 16 to 69% in soil without additional metal. While soil microflora contributed mostly to degradation of pyrene (82%) and benzo[a]anthracene (41%), the fungus enhanced the disappearance of less-soluble polycyclic aromatic compounds containing five or six aromatic rings. Although the heavy metals in the soil affected the activity of ligninolytic enzymes produced by the fungus (laccase and Mn-dependent peroxidase), no decrease in PAH degradation was found in soil containing Cd or Hg at 10 to 100 ppm. In the presence of cadmium at 500 ppm in soil, degradation of PAHs by soil microflora was not affected whereas the contribution of fungus was negligible, probably due to the absence of Mn-dependent peroxidase activity. In the presence of Hg at 50 to 100 ppm or Cd at 100 to 500 ppm, the extent of soil colonization by the fungus was limited.

• MeSH
• Biodegradation, Environmental MeSH
• Cadmium pharmacology   MeSH
• Culture Media MeSH
• Soil Pollutants metabolism   MeSH
• Lignin metabolism   MeSH
• Pleurotus enzymology   growth & development   MeSH
• Polycyclic Aromatic Hydrocarbons metabolism   MeSH
• Soil Microbiology * MeSH
• Mercury pharmacology   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Cadmium MeSH
• Culture Media MeSH
• Soil Pollutants MeSH
• Lignin MeSH
• Polycyclic Aromatic Hydrocarbons MeSH
• Mercury MeSH