White-rot Fungal Cultures Research Articles

Elucidating the role of media nitrogen in augmenting the production of lignin-depolymerizing enzymes by white-rot fungi.

Indigenous white-rot fungal isolates Schizophyllum commune, Phanerochaete chrysosporium, Ganoderma racenaceum, and Lentinus squarrosulus, demonstrating the ability to depolymerize lignin of the crop residues, were studied for their potential to produce ligninolytic enzymes using modified production media under conditions of limiting and excess nitrogen for higher enzymatic expressions. Secretome-rich media on the investigation confirmed the successful production of lignin-depolymerizing enzymes, viz. laccase, lignin peroxidase, manganese peroxidase, and versatile peroxidase. Production of laccases and peroxidases was statistically significant in nitrogen-limiting media with and without the substrate, across all white-rot fungal cultures at 95% confidence interval. Nitrogen-limiting media with the substrate on analysis extracellularly expressed 99.27 U of laccase and 68.48 U of manganese peroxidase in Schizophyllum commune, while 195.14 U of lignin peroxidase was produced by Phanerochaete chrysosporium. Lentinus squarrosulus expressed 455.34 U of laccase and 357.13 U of versatile peroxidase with 250.09 U of laccase and 206.95 U of manganese peroxidase produced by Ganoderma racenaceum for every milliliter of the media used. Nitrogen-limiting media triggered the production of laccase during the initial stages of growth while the expression of peroxidases was predominant at a later stage. Also, this media evinced increased enzymatic yields with low biomass content compared to nitrogen-excess conditions. The extant study confirmed the positive influence of nitrogen-limiting media in the efficient production of ligninolytic enzymes and their suggestive degradation potential for environmental pollutants, making these enzymes a safe, clean alternative to the use of chemicals and the media to be effective for large-scale production of ligninolytic enzymes. IMPORTANCE Lignin on account of its high abundance, complex polymeric structure, and biochemical properties is identified as a promising candidate in renewable energy and bioproduct manufacturing. However, depolymerization of lignin remains a major challenge in lignin utilization, entailing the employment of harsh treatments representing not only an environmental concern but also a waste of economic potential. Developing an alternative green technology to minimize this impact is imperative. Methods using enzymes to depolymerize lignin are the focus of recent studies. Current research work emphasized the efficient expression of the major lignin-depolymerizing enzymes: laccases, lignin peroxidases, manganese peroxidases, and versatile peroxidases from native isolates of white-rot fungus for several biotechnological applications as well as treatment of crop residues for use as ruminant feed in improving productivity. The importance of nitrogen in augmenting the expression of lignin-depolymerizing enzymes and providing a media recipe for the cost-effective production of ligninolytic enzymes is highlighted.

Evaluation of bioremediation strategies for treating recalcitrant halo-organic pollutants in soil environments

The aim of this study was to investigate the bioremediation potential of polychlorinated biphenyls (PCBs) in soil, mimicking three strategies: (a) mycoaugmentation: by the addition of Trametes sanguinea and Pleurotus sajor-caju co-cultures immobilized on sugarcane bagasse; (b) biostimulation: by supplementation of sugarcane bagasse; and (c) natural attenuation: no amendments. The experiments were done in microcosms using Ultisol soil. Remediation effectiveness was assessed based on pollutants content, soil characteristics, and ecotoxicological tests. Biostimulation and mycoaugmentation demonstrated the highest PCBs-removal (approx. 90%) with a significant toxicity reduction at 90 d. The studied strains were able to survive during the incubation period in non-sterilized soil. Laccase, manganese-peroxidase and endoxylanase activities increased significantly in co-cultures after 60 d. Sugarcane bagasse demonstrated to be not only a suitable support for fungal immobilization but also an efficient substrate for fungal colonization of PCBs-contaminated soils. Mycoaugmentation and biostimulation with sugarcane bagasse improved oxidable organic matter and phosphorous contents as well as dehydrogenase activity in soil. Therefore, biostimulation with sugarcane bagasse and mycoaugmentation applying dual white-rot fungal cultures constitute two efficient bioremediation alternatives to restore PCBs-contaminated soils.

Cell-assisted synthesis of conducting polymer - polypyrrole - for the improvement of electric charge transfer through fungal cell wall.

In this research we report the biological synthesis of electrically conducting polymer - Polypyrrole (Ppy). Cell-assisted enzymatic polymerization/oligomerization of Ppy was achieved using whole cell culture and cell-free crude enzyme extract from two white-rot fungal cultures. The selected fungal strains belong to Trametes spp., known laccase producers, commonly applied in bioremediation and bioelectrochemical fields. The biocatalytic reaction was initiated in situ through the copper-containing enzymes biosynthesized within the cell cultures under submerged aerobe cultivation conditions. The procedure was inspired by successful reports of laccase-catalyzed pyrrole polymerization. The usage of whole culture and/or crude enzyme extract has the advantage of overcoming enzyme purification and minimizing the liability of enzyme inactivation through improved stability of enzymes in their natural environment. Spectral and electrochemical techniques (UV-vis spectroscopy, infrared spectroscopy; cyclic voltammetry (CV)) and pH measurements provided insight into the evolution of pyrrole polymerization/oligomerization and the electrochemical features of the final product. Microscopy techniques (optical microscopy and scanning electron microscopy (SEM)) were primary tools for visualization of the formed Ppy particles. The relevance of our research is twofold: Ppy prepared in crude enzyme extract results in enzyme encapsulated within Ppy and/or Ppy-modified fungal cells can be formed when polymerization occurs in whole cell culture. The route of biocatalysis can be chosen according to the desired bioelectrochemical application. The reported study focuses on the improvement of charge transfer through the fungal cell membrane and/or cell wall by modification of the fungal cells with conducting polymer - polypyrrole.

Effect of yeasts on biodegradation potential of immobilized cultures of white rot fungi

The aim was to investigate the effect of yeast organisms on the degradation process by immobilized cultures of ligninolytic fungi. Immobilization was accomplished by 7-day colonization of polyamide mesh with mycelial fragments. Irpex lacteus decolorized >90% of the initial concentration of 150mgl−1 of anthraquinone Remazol Brilliant Blue R dye in three subsequent decolorization cycles and the degradation capacity was not negatively affected by the presence of 106Saccharomyces cerevisiae cells per ml in the mixed culture. The yeast was not able to degrade the dye. I. lacteus biofilm was also resistant to bacterial infection with E. coli. Inoculation of the yeast to pre-formed I. lacteus biofilm culture resulted in a reduction of fungal biomass by 27%. Levels of LiP, MnP and laccase of I. lacteus were not much influenced by S. cerevisiae or E. coli. Similar resilience of P. ostreatus biofilms was observed after exposure to yeast Issatchenkia occidentalis when the fungal degradation capacity measured with Reactive Orange 16 azo dye was maintained over two decolorization cycles. I. occidentalis did not degrade the dye under the conditions used. Formation of densely packed fungal biofilms with abundant extracellular polysaccharide was not impeded by the yeast. Increase of MnP and laccase levels attributable to the presence of I. occidentalis was observed.

Stimulation of the activity of a novel tannase produced in white-rot fungi Phellinus pini, Fomes fomentarius, and Tyromyces pubescens by medium supplementation.

In recent years, tannase has gained increasing interest mainly because of its potential applications. One of the most important functions of tannic acid (TA) hydrolase is the release of gallic acid (GA) from complex tannins. The aim of the study was to determine the dynamic changes in tannase activity depending on the carbon source in the culture medium. An extracellular and intracellular tannase activity analysis was carried out with the use of spectrophotometric analysis and confirmed by capillary electrophoresis in cultures of white-rot fungi: Phellinus pini, Fomes fomentarius, and Tyromyces pubescens. The inducible potential of TA and rapeseed meal on the activity of tannin acyl hydrolase was confirmed during 14 days of culturing. Different effects of the tested compounds on stimulation of tannase activity in selected fungal strains have been demonstrated. We concluded that rapeseed meal was the best inducer of tannase activity in the case of P. pini. However, the highest concentrations of GA were observed after stimulation by the TA in the cultures of F. fomentarius and T. pubescens.

A fermentative approach to ameliorating solid waste challenges within food and hospitality industry

Microbial conversion of organic residues into resource often involves growth and development via modification of complex sugars inherent in the residues. Solid state bioconversion (SSB) process involving mixed culture of white rot fungi was conducted. Product synthesis by the microorganisms and bio-degradation of fruit peels' macromolecules were analyzed chemically and structurally. Protein enrichment was higher when fungal strains were mixed together (141.18 mg g−1) compared with when grown at 4 cm apart (115.62 mg g−1). Different mixtures of fruit peels raised fermentable sugar composition to 500.99 mg g−1 and protein enrichment increased to 160.68 mg g−1 while complex carbon was redistributed. Cellulase activity of 1.33 ± 0.04 units ml−1 and α-amylase activity of 112.46 ± 0.28 units ml−1 were recorded. Fourier transformation infrared (FT-IR) analysis revealed immense modification of complex sugars (cellulose, hemicellulose and lignin) and secretion of simple sugars by filamentous fungi.

Variation in the wood properties of coast redwood trees in New Zealand

There is wide variation in the wood properties of plantation-grown coast redwood (Sequoia sempervirens (D.Don) Endl.) in New Zealand. Contributing factors are the seed source, silviculture, growth rate and age of the trees in the plantation forests. Little is known about how these factors affect the variation of wood properties among and within the trees of New Zealand’s coast redwood forests. The wood of plantation-grown coast redwood trees from three forests in the North Island, New Zealand, was evaluated using butt log and breast height discs and cores, and in vitro decay tests with brown- and white-rot fungal cultures, to determine the variation in the heartwood content, basic density, and red colour and natural durability of the heartwood. The heartwood content of the coast redwood trees was strongly influenced by the age and size of the trees. The basic density of the wood varied widely among the trees in the forests. There were strong radial trends of heartwood colour and natural durability within the stems of trees, with differences among trees at the same growth rings. The heartwood showed a wide range of natural durability, with trees from the older forest stands having a higher proportion of durable heartwood. The diameter growth and age of the coast redwood trees, and the variation among and within the stems of trees will affect the wood properties. Faster diameter growth is likely to increase the heartwood content, and longer rotations will increase the quantity of durable heartwood. The variation among trees suggests there is potential for genetic improvement.

Production of Ligninolytic Enzymes by Cultures of White Rot Fungi

Some Basidiomycota were chosen for studies of key ligninases synthesis (25°C, 30 days) in modified medium (shaken or not cultures) with added wheat straw. Liquid Czapek medium with straw yielded a higher amount of laccase than peroxidase, ground straw induced enzyme worse than chopped straw. With peroxidase the reverse dependencies were observed. Laccase of Lentinus edodes synthesized two enzyme isoforms (ca 30 and 16 kDa). In T. versicolor culture active laccase protein with highest molecular mass ca 65 kDa was found. P. sajor-caju yielded three different peroxidase isoforms. Ligninase biosynthesis depended on strain, straw fragmentation extent, culture method and growth medium.

Phorbol ester degradation in Jatropha seedcake using white rot fungi

White rot fungi are well known for their ability to degrade a wide range of xenobiotics due to their enzymatic systems. Therefore, the present investigation was aimed at screening ten different white rot fungi for degradation of phorbol esters from Jatropha seedcake (JSC). The JSC was fermented with pure cultures of white rot fungi for 20 days under solid state condition. All the white rot fungi tested exhibited degradation of phorbol ester during fermentation of JSC without adversely influencing the nutritional properties of the seedcake. Ganoderma lucidum and Trametes zonata were found to degrade phorbol ester in JSC to undetectable levels. This study demonstrates the potential of white rot fungi for degradation of phorbol esters, a major anti-nutritional factor, in JSC preventing its utilization as cattle feed.Electronic supplementary materialThe online version of this article (doi:10.1007/s13205-013-0174-9) contains supplementary material, which is available to authorized users.

Co-remediation of DDT-contaminated soil using white rot fungi and laccase extract from white rot fungi

2,2-Bis(p-chlorophenyl)-1,1,1-trichloroethane (DDT), one of the most widely used organochlorine pesticides in soil, was banned in the 1970s for agricultural use because of its detrimental impacts on wildlife and harmful effects on human health via the food chain. However, high levels of DDT are frequently detected in agricultural soils in China. Considering this situation, this study investigated the use of white rot fungi and laccase derived from white rot fungi to co-remediate DDT-contaminated soil. A culture of white rot fungi was used to inoculate soil samples and also to extract laccase from. Soil was contaminated with four components of DDT (p,p′-DDE, o,p′-DDT, p,p′-DDD, and p,p′-DDT). Individual DDT components and the sum of the DDT components (p,p′-DDE, o,p′-DDT, p,p′-DDD, and p,p′-DDT—collectively referred to as DDTs) were both analyzed by GC at various stages during the incubation period. The efficacy of co-remediating DDT-contaminated soil using white rot fungi and laccase was tested by investigating how degradation varied with varying amounts of white rot fungi, sterilizing soil, temperature, soil pH, concentrations of DDT, and concentration of the heavy metal ion Cd2+. “”It was concluded that the reduction of DDTs in soil using white rot fungi and laccase was higher than reduction using only white rot fungi or laccase by nearly 14 and 16 %, respectively. Five milliliters fungi per 15 g soil and 6 U laccase per gram soil were the optimal application rates for remediation, as shown by a reduction in DDTs of 66.82 %. The difference in the reduction of individual DDT components and DDTs between natural and sterilized soils was insignificant. The optimal temperature and pH in the study were 28 °C and 4.5, respectively. In addition, reduction of individual DDT components and DDTs increased with increasing concentrations of DDT and decreased with increasing concentrations of Cd2+. Compared with the remediation of DDT using only white rot fungi or laccase, the co-remediation of DDT using white rot fungi and laccase degraded DDT in soil more rapidly and efficiently; the highest reduction of DDTs was 66.82 %.

Removal of bisphenol A and diclofenac by a novel fungal membrane bioreactor operated under non-sterile conditions

Previous studies have confirmed significant removal of various trace organic contaminants (TrOCs) by white-rot fungal cultures under sterile batch test conditions. However, little is known about TrOC removal in continuous flow fungal reactors in a non-sterile environment. This study reports the removal of two TrOCs, namely, bisphenol A and diclofenac, by a fungal membrane bioreactor (MBR). Sterile batch tests with “active” (biosorption and biodegradation) and “chemically inactivated” (biosorption only) Trametes versicolor (ATCC 7731) confirmed biodegradation as the main mechanism for the removal of both compounds. An MBR inoculated with T. versicolor was operated in non-sterile conditions for a period of three months during which diclofenac and bisphenol A were continuously added to the synthetic wastewater. Relatively stable removal of bisphenol A (80–90%) and diclofenac (∼55%) was achieved by applying a hydraulic retention time of two days, at the bisphenol A and diclofenac loadings of 475 ± 25 and 345 ± 112 μg/L.d, respectively.

Comparative study on decolorization of reactive dye 222 by white rot fungi Pleurotus ostreatus IBL-02 and Phanerochaete chrysosporium IBL-03

White rot basidiomycetes have unique ability to decolorize synthetic industrial dyes. Initial experiment was performed with five locally isolated indigenous white rot species fungi S.commune IBL-01 (SC), P. ostreatus IBL-02 (PO) P. chrysosporium IBL-03 (PC), T.versicolor IBL-04 (TV) and G. lucidum IBL-05 (GL), for the selection of white rot fungal cultures based on their maximal decolorization potential. Based on the screening experiment, two white rot fungi P. ostreatus IBL-02 and P. chrysosporium IBL-03 (PC) showing maximum decolorization of dye under study were selected. A comparative study was conducted for the selected white rot fungi to get the maximum decolorization of synthetic azo dye. Different fermentation conditions and nutritional factors were optimized to enhance the efficiency of white rot fungal cultures for dye decolorization. Both cultures produced all the three major ligninolytic enzymes including lignin peroxidase (LiP), manganase peroxidase (MnP) and laccase which are responsible for decolorization process. Under optimum conditions fermentation conditions, P. ostreatus IBL-02 (PO)and P. chrysosporium IBL-03 (PC) decolorized the azo dye by 92.7 and 85.9%, respectively. Key words: Dye decolorization, white rot fungi, ligninolytic enzymes, process optimization

White-rot Fungal Cultures for Degradation of Water Soluble Pollutants: The Aspect of Bacterial Stress

Potential of ligninolytic fungi to degrade organopollutants including synthetic dyes has been proven and the use of immobilized fungal cultures in semisolid state-, trickling-bedand rotating disk reactors for efficient biodegradation of textile dyes repeatedly shown. The effect of bacteria on fungal biofilms and their biodegradation efficiency treated in this study is a factor important in application of fungal cultures under nonsterile conditions. The results will demonstrate tolerance of highly degradative fungi Pleurotus ostreatus, Dichomitus squalens and Irpex lacteus to growth inhibition by coliform and soil bacteria on solid agar media. In static, liquid-medium cultures of I. lacteus working at pH 4.5 and 6.0 for 10 days, the capacity of decolorization of anthraquinone dye Remazol Brilliant Blue R (RBBR) was significantly inhibited by 105106 CFU of Escherichia coli but not Pseudomonas aeruginosa. No specific effect on ligninolytic enzyme production was observed. The presence of 109 CFU of E. coli in semisolid-state cultures of I. lacteus during a 4-week cultivation did not negatively influence the capacity of the fungus to decolorize RBBR. Bacterial counts increased during cultivation but fungal growth was not affected by the presence of the bacterium. Manganesedependent peroxidase was the main enzyme present. The enzyme levels exhibited variations attributable to the presence of the bacterium. Electron microscopy showed that fungal biofilms were dense and stable during long-term runs even in the presence of E.coli. Sustainability and efficiency of fungal biofilms in long-term biodegradation experiments was demonstrated. The work was supported by the projects IAAX00200901 and AV0Z50200510. Biography C. Novotny obtained Ph.D. at Charles University, Prague (1976). He is senior scientist at the Institute of Microbiology of the ASCR, v.v.i., Prague (1976-2010). He was head of Laboratory of Yeast Physiology (19811990) and Laboratory of Experimental Mycology (2002-2006). Topics of research are: microbial physiology, bioremediation and environmental biotechnologies. He has published 53 papers in impacted journals and is assistant editor of Folia Microbiologica.

Comparative study on using carbon or nitrogen limited medium to culture white rot fungi for reactive brilliant red dye K-2BP decolotization under non-sterile conditions

In order to explore ways for the application of white rot fungus in dye effluent treatment under non-sterile conditions, experiment on decolorization of reactive brilliant red was carried out, employing nitrogen-limited and carbon-limited medium with C/N ratio of 56/2.2 and 28/44 (in mmol/L), respectively. The results showed that the decolorization rate reached 92% while culturing white rot fungus with nitrogen-limited medium; however, the decolorization process ended in carbon-limited medium (n(C)/n(N) = 28/44) because of bacterial contamination. In addition, pH rose up to 9.31 after 4 d of decolorization, which was caused by bacterial contamination in the carbon-limited system. Therefore, it is concluded that nitrogen-limited medium can inhibit bacterial growth to some extent while carbon-limited medium is more easily contaminated by bacteria. Nitrogen-limited medium is more suitable in culture of white rot fungus for decolorization of reactive dye. Medium with the ability of inhibiting yeast growth should be developed by adjusting other components of nitrogen-limited medium.

Study of biodegradation products from azo dyes in fungal degradation by capillary electrophoresis/electrospray mass spectrometry

Biodegradation products from four model sulfonated azo dyes Orange II, Acid Orange 8, Food Yellow 3, and 4-[(4-hydroxyphenyl)azo]-benzenesulfonic acid, sodium salt (4HABA), during fungal degradation were determined by capillary electrophoresis coupled with ion trap mass spectrometry (CE–MS) with electrospray ionization and a coaxial sheath flow interface. The development and optimization of this analytical method including the sheath liquid composition and flow rate, nebulizing gas flow rate, carrier electrolyte, and MS voltage are described herein. Detection of unknown biodegradation products was carried out under negative ion mode with base peak electrophorogram (BPE) or extractive ion electrophorogram (EIE) monitoring. A volatile ammonium acetate buffer (10 mM) without organic modifier and a shealth liquid made from 2-propanol and water (80:20, v/v) were suited for the separation and ESI interface. The sulfonated ion was the base peak for model azo dyes and their metabolites containing sulfonic group. Results showed that the tested azo dyes were degraded quickly in the culture of white rot fungus, Pleurotus ostreatus in 3 days with the major biodegradation products being 4-hydroxy-benzenesulfonic acid, 3-methyl-4-hydroxy-benzenesulfonic acid, benzenesulfonic acid, 1,2-naphthoquinone-6-sulfonic acid and 3-methyl-benzenesulfonic acid.

Removal of estrogenic activity of natural steroidal hormone estrone by ligninolytic enzymes from white rot fungi

Natural steroidal hormone estrone (E 1) was treated with the white rot fungus Phanerochaete sordida YK-624 under ligninolytic condition with low-nitrogen and high-carbon culture medium. E 1 decreased by 98% after 5 d of treatment and the activities of ligninolytic enzymes, manganese peroxidase (MnP) and laccase, were detected during treatment, which suggested that the disappearance of E 1 is related to ligninolytic enzymes produced extracellularly by white rot fungus. Therefore, E 1 was treated with MnP and laccase prepared from the culture of white rot fungi. HPLC analysis demonstrated that E 1 disappeared completely in the reaction mixture after 1 h of treatment with either MnP or laccase. Using the yeast two-hybrid assay system, it was also confirmed that both enzymatic treatments completely removed the estrogenic activity of E 1 after 2 h. These results strongly suggest that ligninolytic enzymes are effective in removing the estrogenic activity of E 1.

Relationship of Phenol Oxidase Activity and Hydroxyl-Radical Generation to Wood Degradation by White-Rot Basidiomycetes

Wood degradation, phenol oxidase activity, and the generation of hydroxyl radicals were examined in cultures of eight basidiomycetes that are usually regarded as white-rot fungi. Six of the fungi degraded Japanese beech wood to a significant extent under the conditions used. These six basidiomycetes also had measurable phenol oxidase activity after 1wk in woodcontaining cultures. With two of the six fungi, phenol oxidase activity peaked after 1wk of incubation. One of the six fungi had the highest activity after 6wk. The other three fungi had relatively constant phenol oxidase activities throughout the 8 wk incubation period. The six basidiomycetes that significantly degraded Japanese beech wood also generated significant amounts of hydroxyl radicals in the wood-containing cultures. The combined production of phenol oxidase and hydroxyl radicals in intact cultures of the eight basidiomycetes correlated roughly with the degree of wood degradation in the cultures. Most of the hydroxyl radicals were produced by agents other than phenol oxidase in cultures of white-rot fungi.

Immobilized white-rot fungal biodegradation of phenol and chlorinated phenol in trickling packed-bed reactors by employing sequencing batch operation

The biodegradation of phenol and 2,4,6-trichlorophenol (2,4,6-TCP) by immobilized white-rot fungal cultures was studied in pinewood chip and foam glass bead-packed trickling reactors. The reactors were operated in sequencing batch format. Removal efficiency increased over time and elevated influent phenol and 2,4,6-TCP (800 and 85 mg l −1) concentrations were removed by greater than 98% in 24–30 h batch cycles. Comparable performance between the packing materials was shown. Increased lignin peroxidase (LiP) activity was detected with the introduction of the compounds and optimum activity corresponded to optimum removal periods. Higher LiP activity (16.7–19 U l −1) was detected in glass bead-packed reactor compared to wood chip reactor (0.2–5 U l −1). The presence of Mn 2+ in the wood material possibly effected elevated manganese peroxidase (MnP) activity (0.3–5.8 U l −1) compared to low to negligible activity in the glass bead reactor. Reactor performances are discussed in relation to sequencing batch operation and nutrient requirements necessary to induce and sustain fungal enzyme activity in inert vs. organic material packed systems.

Decolorization of dyes using white-rot fungi and radical-generating reactions

Decolorization of synthetic dyes was performed using cultures of white-rot fungi producing ligninolytic enzymes and radical-generating reactions that could be involved in the mechanism of fungal decolorization. Among the white-rot fungi tested, Pleurotus ostreatus exhibited the highest decolorization rates, and also the highest production of laccase and Mn-peroxidase. P. ostreatus strain f6 gave 69% decolorization of Eosin Yellowish, 96% of Evans Blue, 75% of Phenol Red (all at 1 mM) and 88% of Poly B-411 (20 ppm) during a 14-day treatment. Treatment with Cu/succinic acid/H2O2 resulted in 96% decolorization of Evans Blue and Poly B-411 within 24 h. However, only 48% and 2% decolorization was achieved with Phenol Red and Eosin Yellowish, respectively. Similar decolorization rates were also obtained when Cu was replaced with Co. The results show that treatment of dye-containing solutions with both fungal cultures and biomimetic catalytic reactions results in decolorization.

Mycoremediation of PAH-contaminated soil.

Out of a number of white-rot fungal cultures, strains of Irpex lacteus and Pleurotus ostreatus were selected for degradation of 7 three- and four-ring unsubstituted aromatic hydrocarbons (PAH) in two contaminated industrial soils. Respective data for removal of PAH in the two industrial soils by I. lacteus were: fluorene (41 and 67%), phenanthrene (20 and 56%), anthracene (29 and 49%), fluoranthene (29 and 57%), pyrene (24 and 42%), chrysene (16 and 32%) and benzo[a]anthracene (13 and 20%). In the same two industrial soils P. ostreatus degraded the PAH with respective removal figures of fluorene (26 and 35%), phenanthrene (0 and 20%), anthracene (19 and 53%), fluoranthene (29 and 31%), pyrene (22 and 42%), chrysene (0 and 42%) and benzo[a]anthracene (0 and 13%). The degradation of PAH was determined against concentration of PAH in non-treated contaminated soils after 14 weeks of incubation. The fungal degradation of PAH in soil was studied simultaneously with ecotoxicity evaluation of fungal treated and non-treated contaminated soils. Compared to non-treated contaminated soil, fungus-treated soil samples indicated decrease in inhibition of bioluminescence in luminescent bacteria (Vibrio fischerii) and increase in germinated mustard (Brassica alba) seeds.