Lignin is a major component of perennial plants and is probably the second most abundant organic polymer on earth, next to cellulose. It is a widespread potential carbon source for both parasitic and saprophytic fungi. Lignin is a term given to a group of closely related, high molecular weight compounds, that are branched polymers of three substitued alcohols: p-coumaryl alcohol, coniferyl alcohol and sinapyl alcohol. Degradation of wood is slow process in which may participate bacteria and fungi. Nevertheless, wood-rotting fungi are the only organisms that have been clearly demonstrated to extensively degrade lignin to carbon dioxide. White-rot fungi produce extracellular enzymes responsible for oxidative degradation of lignin.The most important enyzmes are Mn-dependent peroxidase, laccase or aryl alcohol oxidase. Earlier investigations showed, that some white-rot fungi are able to decompose aromatic organopollutants, like PAH's or some industrial dyes. The aim of research is to prepare fungal mutants with enhanced degradation ability and the study of their possible use in bioremediation processes.

Our collection of basidiomycetes is the only integral collection of hymenomycetes in this country, the treasury of some preserved and rare species, the protector of patented strains. It is a basis for screening of strains possessing important metabolic activities, the supplier of cultures to different institutions in this and foreign countries. The Culture Collection of Basidiomycetes (CCBAS) is a member of the Federation of Czechoslovak Culture Collections and the World Federation of Culture Collections and it is listed under the number 558 in the World Center for Culture Collections of Microorganisms.

The ability of fungi to accumulate metals is well-known phenomenon that is studied from various viewpoints. In our research team, two main problems are studied: distribution of heavy metals in fruit bodies of wood-rotting fungi collected in both polluted and unpolluted regions and, responses of cultures of wood-rotting fungi to exposure of heavy metal salts.

In practice, wood-rotting fungi may take up heavy metals from substrate or from atmosphere. As the wood-inhabiting fungi have limited contact with the soil and content of most heavy metals in wood is negligible, the main source of anthropogenic metals in these fungi is dry or wet atmospheric deposition. Fruit bodies of six wood-rotting fungal species are collected in areas with different level of atmospheric pollution by heavy metals in the Czech Republic. Stastitically significant differences were obtained e.g. between samples from the National Park Sumava and samples from the capital Prague. The aim of research is the monitoring of atmospheric pollution by heavy metals with fungi.

Wood-rotting fungi similarly to other filamentous fungi form branching mycelium. Metals are bound to structures of outer layer of the cell wall. A key role of polysaccharides in the process is generally accepted, although sorption to peptides or pigments may also occurre. When cultivated submergedly, wood-rotting fungi give pellets with good mechanical properties and diameter ranging from 2 mm to 2 cm. Our previous experiments with equimolar solutions of different metals showed that there are differences in biosorption among fungi. The aim of research is to develope good biosorbent for removal of cadmium and other toxic metals from waste or industrial water.

Long time exposure of cultures of higher fungi in the presence of heavy metals increases content of metals in the mycelium. Relationship between Cd concentration in the culture liquid and Cd content in mycelium of Daedalea quercina was well demonstrated. Heavy metals are translocated through cell wall into the mycelium where they influence metabolism and morphology of the fungal culture. We described for example inhibition of activity of Mn-dependent and Mn-independent peroxidases of Stereum hirsutum, enzymes participating in biodegradation of lignin, and delayed decolorization of polymeric dye Poly R-478 by cultures of several basidiomycetes. Hyphae of cadmium-treated cultures of Daedalea quercina were shorter and thicker than those in control samples. Limited branching and changes in hyphae orientation, and in some cases changes in color of fungal cultures were found as well. The aim of this research is to investigate changes in physiology and metabolic activities of wood-rotting fungi caused by stress concentrations of cadmium.