An experimental device is developed and approved for biological degradation of toxic substances in waste water using acid-troph immobilized mycelium. It is established that use of lignocellulose waste products as a medium for immobilizing makes it possible to utilize them and exclude formation of new weakly degraded waste products of treated medium.Development of contemporary industry leads to an increase in the amount of toxic and nontoxic waste products. Many of these compounds (xenobiotics) have high resistance to chemical and biological decomposition, a capacity to stay in the environment for tens of years and be carried through the food chain, leading to a reduction in biodiversity, disruption of the ecological balance within living nature and development of serious human illnesses. In view of this, there is an urgent requirement for developing methods of degrading these waste products, although it is very important to use ecologically clean methods, excluding situations when utilization of one waste product produces another, less toxic, but weakly decomposed xenobiotic waste product. In particular, this relates to polymer media used extensively for immobilization.The aim of the research was development of a method for biocatalytic degradation of toxic substances in waste water using a mycelium of higher basidial acid-troph fungus immobilized in a biodegradable medium, i.e., an industrial producer of laccase enzyme, capable of biotransformation of a broad range of xenobiotics. Laccase exhibits a broad substrate specificity with respect to various compounds, having high activity and stability, which makes it possible to use it for practical purposes, in particular, for cleaning waste water. The producer of high-potential laccase Trametes hirsuta 56 (Wulfen.) pilat (RF patent No. 2345135, C 12 N 9/58, C 12 N 1/14, C 12 R 1/645) is related to a number of nontoxic wood polypore fungi, enriching lignocellulose substrates with albumin and biologically active substances. Thus, the spent medium of a biofiltration module will not only be a material easily decomposed in nature, but it may also be used as a fertilizer, soil improver or feeding addition.Laccase activity is determined with respect to total oxidase activity, measured spectrophotometrically at 410 nm using pyrocatechol as a substrate. For the selected producer strain it has been established that up to 80% of the oxidase fermentative complex is laccase.As a result of these experiments, it has been established that lignocellulose waste products, such as oak sawdust, pine sawdust, flax woody fiber, considerably increase synthesis of biocatalytic enzyme (laccase), which increases the efficiency of xenobiotic biodegradation.Experiments using different types of medium, such as oak sawdust, flax woody fiber, steel sponge and luffa vegetable sponge, showed that the most effective method for immobilizing laccase producer fungus is accomplished in media