Reevaluation of the manganese requirement for the biobleaching of kraft pulp by white rot fungi

Manganese dependent peroxidase (MnP) is the main enzyme implicated in the biobleaching of kraft pulps by white rot fungi. The goal of this study was to evaluate the Mn requirement for biobleaching of eucalyptus oxygen delignified kraft pulp (OKP) by various white rot fungi: Trametes versicolor, Phanerochaete sordida, Phlebia radiata, Stereum hirsutum and Bjerkandera sp. strain BOS55. All of the strains tested produced MnP and provided extensive bleaching of OKP when 33 μM Mn was included in the medium. Bjerkandera sp. strain BOS55 was the only strain that also displayed MnP production and biobleaching activity of EDTA-extracted OKP in the complete absence of Mn. However, MnP and biobleaching activity in the absence of Mn was dependent on the presence of organic acids in the medium. The fact the biobleaching was correlated to MnP activity irrespective of whether Mn was present or absent suggests that there may be roles for MnP in Bjerkandera under Mn-deficient conditions. Although manganese-independent peroxidase (MIP) and lignin peroxidase (LiP) were also detected, the titres were much smaller in comparison with those of MnP, so their relative role in biobleaching can be predicted to have a minor importance in comparison with MnP. Only in the case of Bjerkandera, was the expression of LiP stimulated in the presence of oxalate but final brightness was not substantially affected.     

Covalent immobilisation of manganese peroxidases (MnP) from Phanerochaete chrysosporium and Bjerkandera sp. BOS55

Manganese peroxidases (MnP) from Phanerochaete chrysosporium and Bjerkandera sp. BOS55 were immobilised in glutaraldehyde–agarose gels. Four different strategies were considered concerning the activation of the support (low or high density) and the ionic strength (low or high). In terms of immobilisation rate and yield, better results were obtained when low ionic strength conditions and high density activated support (75 μEq/ml) were used. Immobilisation proceeds initially with an ionic adsorption which facilitates the further covalent attachment of the enzyme to the support. An almost complete immobilisation has been attained in a very short period (0.5–2 h). Immobilisation maintained a high percentage of MnP activity for long periods of time (activity levels of 50–60% after more than 1 year at room temperature storage). Other desirable effects such as increased thermostability at 50–60 °C for MnP from Bjerkandera and higher resistance to high H₂O₂ concentrations for MnP for P. chrysosporium were also obtained. This latter is quite an interesting feature because it avoids the inactivation of the enzyme in the presence of an unbalanced concentration of H₂O₂. The improved characteristics of the immobilised MnP make its application in several fields such as the enzymatic oxidation of hardly degradable compounds more feasible.     

Fungal degradation of lipophilic extractives in eucalyptus globulus wood

Solid-state fermentation of eucalypt wood with several fungal strains was investigated as a possible biological pretreatment for decreasing the content of compounds responsible for pitch deposition during Cl2-free manufacture of paper pulp. First, different pitch deposits were characterized by gas chromatography (GC) and GC-mass spectrometry (MS). The chemical species identified arose from lipophilic wood extractives that survived the pulping and bleaching processes. Second, a detailed GC-MS analysis of the lipophilic fraction after fungal treatment of wood was carried out, and different degradation patterns were observed. The results showed that some basidiomycetes that decreased the lipophilic fraction also released significant amounts of polar extractives, which were identified by thermochemolysis as originating from lignin depolymerization. Therefore, the abilities of fungi to control pitch should be evaluated after analysis of compounds involved in deposit formation and not simply by estimating the decrease in the total extractive content. In this way, Phlebia radiata, Funalia trogii, Bjerkandera adusta, and Poria subvermispora strains were identified as the most promising organisms for pitch biocontrol, since they degraded 75 to 100% of both free and esterified sterols, as well as other lipophilic components of the eucalypt wood extractives. Ophiostoma piliferum, a fungus used commercially for pitch control, hydrolyzed the sterol esters and triglycerides, but it did not appear to be suitable for eucalypt wood treatment because it increased the content of free sitosterol, a major compound in pitch deposits.     

Fungal Degradation of Lipophilic Extractives in Eucalyptus globulus Wood

Solid-state fermentation of eucalypt wood with several fungal strains was investigated as a possible biological pretreatment for decreasing the content of compounds responsible for pitch deposition during Cl₂-free manufacture of paper pulp. First, different pitch deposits were characterized by gas chromatography (GC) and GC-mass spectrometry (MS). The chemical species identified arose from lipophilic wood extractives that survived the pulping and bleaching processes. Second, a detailed GC-MS analysis of the lipophilic fraction after fungal treatment of wood was carried out, and different degradation patterns were observed. The results showed that some basidiomycetes that decreased the lipophilic fraction also released significant amounts of polar extractives, which were identified by thermochemolysis as originating from lignin depolymerization. Therefore, the abilities of fungi to control pitch should be evaluated after analysis of compounds involved in deposit formation and not simply by estimating the decrease in the total extractive content. In this way, Phlebia radiata, Funalia trogii, Bjerkandera adusta, and Poria subvermispora strains were identified as the most promising organisms for pitch biocontrol, since they degraded 75 to 100% of both free and esterified sterols, as well as other lipophilic components of the eucalypt wood extractives. Ophiostoma piliferum, a fungus used commercially for pitch control, hydrolyzed the sterol esters and triglycerides, but it did not appear to be suitable for eucalypt wood treatment because it increased the content of free sitosterol, a major compound in pitch deposits.     

Widespread presence of hydrophobic paralytic shellfish toxins in Gymnodinium catenatum

The toxic dinoflagellate Gymnodinium catenatum Graham produces a newly discovered sub-class of paralytic shellfish toxins (PSTs, saxitoxins) that contain a hydroxybenzoate moiety in place of the carbamoyl group (GC toxins: GC1–GC3). GC toxins bind strongly to sodium channels and their lipophilic nature may increase their potential to bioaccumulate in marine organisms. Cultures Australian G. catenatum strains were found to contain 12–63 mol% GC toxins. The GC toxins were also detected in strains from China (38 mol%), Japan (1–2 mol%), Portugal (58 mol%), Spain (36–54 mol%), and Uruguay (10–16 mol%). A cluster analysis of molar proportions of saxitoxin derivatives produced by strains showed clear clustering by country/region of origin, indicating that GC toxins may be very useful markers to identify the source of G. catenatum in the case of new outbreaks. The GC toxins dominate the toxin profiles of many G. catenatum strains, and can contribute significantly to sample toxicity, yet these toxins may easily escape detection using conventional chromatography, resulting in significant underestimates of sample toxicity. This has significant implications for shellfish monitoring and safety.     

Degradation and detoxification of softwood extractives by sapstain fungi

Wood extractives (resin) cause pitch deposition problems and effluent toxicity in pulp and papermaking. The ability of six sapstaining fungi to degrade and detoxify extractive constituents in Scots pine sapwood was examined, and the results were compared with those obtained with the commercial depitching fungus Cartapip (Ophiostoma piliferum). Pestalotiopsis crassiuscula and O. piliferum were the best strains and they provided high reductions of total resin (50–60% in 6 weeks). Both strains were highly effective in the degradation of individual extractive components including triglycerides, diglycerides and free fatty acids. Although all strains displayed moderate to high pitch degradation, their detoxifying capacity was limited. Two important exceptions were Ceratocystis deltoideospora and O. piliferum that caused a 11–14-fold decrease in toxicity (Microtox bioassay). These results indicate the potential of wood pretreatment with the selected sapstain fungi for minimizing pitch problems and decreasing effluent toxicity in pulping.     

Hydrogen and polyhydroxybutyrate producing abilities of microbes from diverse habitats by dark fermentative process

Thirty five bacterial isolates from diverse environmental sources such as contaminated food, nitrogen rich soil, activated sludges from pesticide and oil refineries effluent treatment plants were found to belong to Bacillus, Bordetella, Enterobacter, Proteus, and Pseudomonas sp. on the basis of 16S rRNA gene sequence analysis. Under dark fermentative conditions, maximum hydrogen (H₂) yields (mol/mol of glucose added) were recorded to be 0.68 with Enterobacter aerogenes EGU16 followed by 0.63 with Bacillus cereus EGU43 and Bacillus thuringiensis EGU45. H₂ constituted 63–69% of the total biogas evolved. Out of these 35 microbes, 18 isolates had the ability to produce polyhydroxybutyrate (PHB), which varied up to 500 mg/l of medium, equivalent to a yield of 66.6%. The highest PHB yield was recorded with B. cereus strain EGU3. Nine strains had high hydrolytic activities (zone of hydrolysis): lipase (34–38 mm) – Bacillus sphaericus strains EGU385, EGU399 and EGU542; protease (56–62 mm) – Bacillus sp. strains EGU444, EGU447 and EGU445; amylase (23 mm) – B. thuringiensis EGU378, marine bacterium strain EGU409 and Pseudomonas sp. strain EGU448. These strains with high hydrolytic activities had relatively low H₂ producing abilities in the range of 0.26–0.42 mol/mol of glucose added and only B. thuringiensis strain EGU378 had the ability to produce PHB. This is the first report among the non-photosynthetic microbes, where the same organism(s) – B. cereus strain EGU43 and B. thuringiensis strain EGU45, have been shown to produce H₂ – 0.63 mol/mol of glucose added and PHB – 420–435 mg/l medium.     

基底颜色对两种沙蜥体色变异的影响

生存在不同基底颜色环境下的爬行动物种群通常表现出丰富的体色地理变异, 其体色变化的潜在机制具有多样性。变色沙蜥(Phrynocephalus versicolor)和草原沙蜥(P. frontalis)具有较近的遗传关系, 曾被认为与荒漠沙蜥(P. przewalskii)组成同一系统发育种组。本文应用光纤光谱仪(AvaSpec-2048), 通过记录沙蜥背部体表12个部位的皮肤光反射率, 定量比较在黑化环境下的深色变色沙蜥与非黑化环境下的浅色草原沙蜥自然体色变异, 研究其种群体色变异是否具有时间可逆性, 并探讨基底颜色对沙蜥体色的影响机制。研究结果表明, 黑化生境下的变色沙蜥体色显著深于非黑化枯黄色生境下的草原沙蜥。此外, 对黑化与非黑化样本开展的生境互换移植围栏实验, 即把枯黄色生境中非黑化的草原沙蜥移植于黑色的基底环境中饲养, 把黑化生境中黑化的变色沙蜥移植于枯黄色生境中饲养。结果表明, 饲养1周后黑化群体背部6个检测部位的光反射率显著变大, 其他部位均无显著变化; 而非黑化群体只有左后肢和背部右上方2个部位的皮肤光反射率发生显著变化, 其他部位反射率无显著变化。结果表明, 变色沙蜥体色变异能力比草原沙蜥强, 体色表型可能已经在两个近缘沙蜥物种中稳定遗传, 基底生境颜色的短期变化在统计学上能引起肉眼难以识别的轻微的体色变异, 个体发育相关的一些遗传因素可能对体色变异起控制 作用。     

Detection, quantification and identification of fungal extracellular laccases using polyclonal antibody and mass spectrometry

This study presents a combined method to analyze extracellular fungal laccases using a new anti-laccase antibody together with the identification of tryptic laccase peptides by mass spectrometry (nanoLC–ESI–MS/MS). The polyclonal anti-laccase antibody LccCbr2 was raised against peptides designed from the copper binding region II of fungal laccases using in silico data obtained from GenBank database. As a consequence, detection requires denaturation of the enzymes due to the stable conformation of the copper binding region II. The specificity of the antibody was shown with denatured laccase Lcc1 of Coprinopsis cinerea and laccase of Hypholoma fasciculare. LccCbr2 detected amounts as low as 5 ng of highly purified laccase, indicating a possible use of the antibody for quantification of laccase proteins. Denatured extracellular laccases from culture supernatants of the basidiomycetes C. cinerea, H. fasciculare, Lentinula edodes, Mycena sp., Piriformospora indica, Pleurotus cornucopiae, Pleurotus ostreatus, Pycnoporus cinnabarinus, Trametes versicolor and furthermore the ascomycete Verpa conica were detected with apparent molecular masses between 60 and 70 kDa by LccCbr2. The identity of extracellular laccases from C. cinerea, H. fasciculare, P. ostreatus, P. cinnabarinus and T. versicolor were verified by tryptic peptides using nanoLC–ESI–MS/MS.     

The effect of phenolic acids and molasses spent wash concentration on distillery wastewater remediation by fungi

The effect of gallic acid, vanillic acid, and molasses spent wash (MSW) concentration on growth and decolourizing capability of four fungi (Geotrichum candidum, Coriolus versicolor, Phanerochaete chrysosporium and Mycelia sterilia) was studied. Fungal growth was inhibited to a varying extent in the presence of gallic and vanillic acid, except for G. candidum, which was unaffected by gallic acid. G. candidum and P. chrysosporium growth rates increased in the presence of increasing concentrations of MSW (up to 50% v/v), however, growth of M. sterilia and C. versicolor was inhibited at spent wash concentrations above 5% (v/v). Increasing the concentration of MSW from 6·25% (v/v) to 12·5% (v/v) increased the decolourizing ability of each fungus, except for M. sterilia. C. versicolor exhibited greatest colour removal with a reduction of 0·43 units at A₄₇₅ (equivalent to 53% colour reduction) after 10 days growth in 12·5% (v/v) MSW.     

Chemical characterization of pitch deposits produced in the manufacturing of high-quality paper pulps from hemp fibers

The composition of pitch deposits occurring in pulp sheets and mill circuits during soda/anthraquinone pulping and elemental chlorine-free pulp bleaching of bast fibers of industrial hemp (Cannabis sativa) was studied. Pitch deposits were extracted with acetone, and the extracts analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). Acetone extracts (15-25% of pitch deposits) were constituted by the defoamers used at the mill and by lipophilic extractives from hemp fibers. Acetone-insoluble residues (75-85% of pitch deposits) were analyzed by pyrolysis-GC/MS in the presence and absence of tetramethylammonium hydroxide. These residues were constituted by salts of fatty acids (arising from hemp fibers) with calcium, magnesium, aluminum and other cations that were identified in the deposits. It was concluded that inappropriate use of defoamer together with the presence of multivalent ions seemed to be among the causes of hemp extractives deposition in the pitch problems reported here.     

Lactobacillus harbinensis sp. nov., consisted of strains isolated from traditional fermented vegetables 'Suan cai' in Harbin, Northeastern China and Lactobacillus perolens DSM 12745

Taxonomical analysis of two genetically distinguished Lactobacillus strains isolated from traditional Chinese fermented vegetables ‘Suan cai’ was performed. They formed l-lactate from glucose, were facultatively heterofermentative, and had a DNA G+C content of 53–54 mol%. They fermented d- and l-arabinose. They produced lactate, ethanol and acetate from gluconate at a molar ratio of 1.1:0.4:0.7. Phylogenetic analysis of 16S rDNA revealed that the two strains were closely related to L. perolens. DNA–DNA hybridization analysis revealed that the two strains were different from L. perolens type strain DSM 12744 and formed a separate cluster with L. perolens DSM 12745. G+C molar content of DNA of the former is 51%, whereas those of the latter strains were in the range of 53–54%. Based on the results, we propose that the new species be named L. harbinensis sp. nov. and that L. perolens DSM 12745 be reclassified as L. harbinensis DSM 12745. The type strain of L. harbinensis DSM 16991^T (=AHU 1762^T=SBT 10908^T).     

Characterization of Desulfomicrobium salsuginis sp. nov. and Desulfomicrobium aestuarii sp. nov., two new sulfate-reducing bacteria isolated from the Adour estuary (French Atlantic coast) with specific mercury methylation potentials

Three strains of sulfate-reducing bacteria (ADR21, ADR26 and ADR28) were isolated from Adour estuary sediments (French South Atlantic coast). Cells of these isolates were rod-shaped, motile and stained Gram-negative. The 16S rRNA and dsrAB genes sequence analyses indicated that these three strains belonged to the genus Desulfomicrobium within the delta Proteobacteria, with Desulfomicrobium escambiense strain DSM10707^T as their closest relative. According to phenotypic characteristics, strains ADR21 and ADR28 could be considered as members of the same species. The relatedness values, based on DNA–DNA hybridization studies, between strains ADR21/DSM10707^T, ADR26/DSM10707^T and ADR21/ADR26 ranged between 30.6–40.8%, 45.2–43.0% and 19.0–26.4%, respectively. Strains ADR21 and ADR28 grew well on lactate, fumarate, malate, formate, ethanol and H₂/acetate in the presence of sulfate as an electron acceptor. Thiosulfate, nitrate, fumarate and DMSO were alternative electron acceptors. Malate was well fermented but pyruvate and fumarate only poorly. Strain ADR26 could not grow on ethanol or fumarate and was unable to use DMSO or fumarate as electron acceptors. The three new strains exhibited differences compared to the type strain of D. escambiense, such as temperature optima, substrate utilization and mercury methylation capacities. On the basis of both genetic and phenotypic evidences, strain ADR21 is proposed as the type strain of the species Desulfomicrobium salsuginis sp. nov., and strain ADR26 as the type strain of the species Desulfomicrobium aestuarii sp. nov.     

Diversity in cyclic sesquiterpene production by Gossypium hirsutum

Major sesquiterpene components of oil of Texas Race Stock 810 of Gossypium hirsutum were - and β-selinene. This is the seventh cyclic terpene type found to date in this genus. Both - and β-selinene, along with aromadendrene, were found but only as minor components of extracts of several domestic cultivars of G. hirsutum.     

Acetic acid bacteria as enantioselective biocatalysts

Acetic acid bacteria (five strains of Acetobacter and five strains of Gluconobacter) were used for the biotransformation of different primary alcohols (2-chloropropanol and 2-phenylpropanol) and diols (1,3-butandiol, 1,4-nonandiol and 2,3-butandiol). Most of the tested strains efficiently oxidized the substrates. 2-Chloropropanol and 1,3-butandiol were oxidized with good rates and low enantioselectivity (enantiomeric excess=18–46% of the S-acid), while microbial oxidation of 2-phenylpropanol furnished (S)-2-phenyl-1-propionic acid with enantiomeric excess (e.e.) >90% with 10 strains. The dehydrogenation of 2,3-butandiol was strongly dependent on the stereochemistry of the substrate; the meso form gave S-acetoin with all the tested strains, the only exception being a Gluconobacter strain. The formation of diacetyl was observed only by using R,R-2,3-butandiol with Acetobacter strains. Oxidation of 1,4-nonandiol gave γ-nonanoic lactone in one step, although with moderate enantioselectivity.     

Deinococcus misasensis and Deinococcus roseus, novel members of the genus Deinococcus, isolated from a radioactive site in Japan

Two gamma- and UV-radiation resistant, Gram-positive, red- or pink-pigmented, rod-shaped, strictly aerobic, oxidase- and catalase-positive bacterial strains, TDMA-25^T and TDMA-uv51^T, were isolated from fresh water collected at Misasa, a radioactive site in Japan. Phylogenetic analysis based on 16S rRNA gene sequences placed both in a distinct lineage in the family Deinococcaceae, and the highest degrees of sequence similarity determined belonged to Deinococcus maricopensis LB-34^T (88.8–89.3%), Deinococcus pimensis KR-235^T (86.4–86.7%) and Deinococcus yavapaiensis KR-236^T (86.1%). The DNA G+C content of the strains was 53–58 mol%. The major respiratory quinone was MK-8. The predominant fatty acids were C_15:0 iso, C_16:0 iso, C_13:0 iso, C_17:0 iso, C_16:0, C_13:0 anteiso, C_15:0 and C_12:0 iso. The strains degraded gelatin, casein, starch and Tween 80. Unique physiological characteristics, differences in their fatty acid profiles, and genotypic and phylogenetic features, differentiated strains TDMA-25^T and TDMA-uv51^T from closely related Deinococcus species. Hence, the two strains are described as novel species of the genus Deinococcus. The names Deinococcus misasensis sp. nov. (type strain TDMA-25^T=JCM 14369=NBRC 102116=CCUG 53610) and Deinococcus roseus sp. nov. (type strain TDMA-uv51^T=JCM 14370=NBRC 102117=CCUG 53611) are proposed.     

Immobilization of wood-rotting fungi laccases on modified cellulose and acrylic carriers

Extracellular laccases produced by three different wood-rotting fungi, Cerrena unicolor, Heterobasidion annosum and Trametes versicolor, were immobilized via covalent bonds formation on DEAE-Granocel 500, CM-Granocel 500, and acrylic carriers. Out of the tested carriers, only the DEAE-Granocel 500, which was activated by divinyl sulphone appeared to be a suitable matrix for the expression of enzymic activity. Only one laccase of all the tested enzymes produced by C. unicolor showed the best binding to the carrier and a satisfactory enzymic activity. The immobilized laccase exhibited the highest enzymic activity at pH 5.2 and it was more resistant to thermal denaturation than the native enzyme. At 90 °C, it retained 75% activity compared to the free enzyme. It was also more stable during storage at 4 °C: after 4 months the immobilized laccase retained 98% of initial activity. Immobilized C. unicolor laccase was active in 10–60% concentration of methanol, acetone, isopropanol or acetonitrile. The best enzymic activity was observed in 20% solution of acetonitrile in buffer.     

Cultivation and preservation of vinegar bacteria

Ten strains of acetic acid bacteria were investigated for their characteristics of growth and metabolism. The strains were identified as those presently in use for industrial vinegar production in southern Germany. At the time of isolation from industrial acetators the total concentrations, i.e. acetic acid (w/v) plus ethanol (v/v), of the fermenting vinegars were 6.1–14.9%. The applicability of a previously described method for starter preparation was examined for the various isolates as well as for the type strains of species of the genera Gluconobacter and Acetobacter. Isolates from cider or wine vinegar fermentations grew readily in RAE-medium to total counts of >1×10⁹ cells ml⁻¹. For the cultivation of strains isolated from spirit vinegar fermentations AE-medium proved most suitable. Cultures of these strains exhibited lag phases of 2–5 days and grew up to total counts of <1×10⁹ cells ml⁻¹. All type strains could be grown on RAE-agar. The use of 20% malt extract as cryo-protectant was effective for the preservation of all strains. Upon revitalization the cultures were suitable as inoculum for starting fermentations in pilot acetators. 16S rRNA-targeted oligonucleotide probes were constructed which were species specific for Gluconobacter oxydans or Acetobacter aceti or group specific for Acetobacter europaeus/Acetobacter xylinum. The probes hybridized with the DNA of the respective type strains. Four isolates were allotted to A. europaeus/A. xylinum applying the group specific probe. The DNA of six of the Acetobacter sp. hybridized with none of the probes.     

一株新分离的云芝栓孔菌Z-1应用于木质素降解及染料脱色

木质素是一种非结晶性的复杂三维网状酚类高分子聚合物,被认为是木质纤维素生物质抗降解的天然屏障。探索并开发高效降解木质素的微生物资源已成为近些年来的研究焦点。本研究对新分离的一株具有潜在木质素降解能力的菌株Z-1开展了系列研究。首先通过形态学和系统发育分析将菌株Z-1鉴定为云芝栓孔菌Trametes versicolor。平板定性检测初步表明云芝栓孔菌T. versicolor Z-1具有较强的产过氧化物酶和漆酶能力。以木质素为唯一碳源时,T. versicolor Z-1对木质素的降解率和脱色率分别可达13.38%和26.43%。酶活检测分析表明该菌主要是通过分泌漆酶和锰过氧化物酶（manganese peroxidase,MnP）降解木质素。利用傅里叶变换红外光谱（fourier transform-infrared spectroscopy,FT-IR）、扫描电镜（scanning electron microscope,SEM）及气相色谱-质谱联用（gas chromatography-mass spectroscopy,GC-MS）对云芝栓孔菌T. versicolor Z-1降解后木质素残渣结构以及代谢物的鉴定分析结果证实了该菌对木质素的强降解能力,并表明该菌对木质素的降解途径包括酚醚键的断裂、芳香环侧链氧化裂解以及芳香环开环反应等。此外,该菌还对多种芳香类染料展现出了强的脱色能力,其中对刚果红、孔雀石绿和考马斯亮蓝R-250 3种染料的脱色率达到100%。本研究表明云芝栓孔菌T. versicolor Z-1具有应用于工业化木质素降解与芳香化合物类染料脱色的开发前景。     

Time course of fungal removal of lipophilic extractives from Eucalyptus globulus wood

Free and esterified sitosterol, the main lipophilic constituents of eucalypt wood extractives, have been associated with the formation of pitch deposits during manufacturing of environmentally-sound paper pulp from Eucalyptus globulus wood. These, and other lipophilic compounds, were analyzed by gas chromatography-mass spectrometry in the course of wood treatments (up to 7 weeks) with four extractive-degrading fungi in order to optimize biotechnological control of pitch deposition in eucalypt pulp (with moderate loss of wood weight). In contrast to commercialized fungi used in pitch control, which are not able to degrade sitosterol, the fungi investigated in this paper produced a rapid decline of both free and esterified sterols in wood. The degradation rate of steroid hydrocarbons and squalene was moderate, and the amount of steroid ketones (probably formed during oxidative degradation of steroids) and triglycerides increased at different stages of wood treatment. Up to 95% removal of total steroids (including free and esterified sterols, steroid ketones and steroid hydrocarbons) by fungi was obtained at the end of wood treatment under the solid-state fermentation conditions used. The most promising results from the point of view of industrial applicability, however, were obtained after 1-2 weeks of treatment with either Phlebia radiata or Poria subvermispora, which enabled 70% steroid removal with a moderate wood weight loss of 1-4%.