Enhancement of laccase production by Cerrena unicolor through fungal interspecies interaction and optimum conditions determination.

The present study aimed to identify a pair of fungal strains that promote laccase production in the co-cultivation of white-rot basidiomycetes and to determine the optimum conditions to enhance enzyme synthesis under co-fermentation of mandarin peels. Co-cultivation of Cerrena unicolor with Trametes versicolor, Lenzites betulina, and Panus lecomtei led to up-regulation of laccase activity. Moreover, interspecific interaction of Cerrena unicolor and Trametes versicolor induced the production of two new laccase isoenzymes. By contrast, interactions of Cerrena unicolor with Trametes coccineus and Trametes hirsuta resulted in a multiple decreased ability of Cerrena unicolor to produce laccase. Co-cultivation of Cerrena unicolor with other fungi 3- to 12-fold down-regulated manganese peroxidase (MnP) activity. The outcomes of these fungal interactions are closely related to the initial concentration and availability of the nutrients, the partners' inoculum ratio, time, and sequence of their inoculation. Co-cultivation of Cerrena unicolor and Trametes versicolor in fermenter resulted in the accumulation of 476 U/mL laccase and 1.12 U/mL MnP.

Antifungal Activity of Medicinal Mushrooms and Optimization of Submerged Culture Conditions for Schizophyllum commune (Agaricomycetes).

The main goal of the present study was the exploration of the antifungal properties of Agaricomycetes mushrooms. Among twenty-three tested mushrooms against A. niger, B. cinerea, F. oxysporum, and G. bidwellii, Schizophyllum commune demonstrated highest inhibition rates and showed 35.7%, 6.5%, 50.4%, and 66.0% of growth inhibition, respectively. To reveal culture conditions enhancing the antifungal potential of Sch. commune, several carbon (lignocellulosic substrates among them) and nitrogen sources and their optimal concentrations were investigated. Presence of 6% mandarin juice production waste (MJPW) and 6% of peptone in nutrient medium promoted antifungal activity of selected mushroom. It was determined that, extracts obtained in the presence of MJPW effectively inhibited the grow of pathogenic fungi. Moreover, the content of phenolic compounds in the extracts obtained from Sch. commune grown on MJPW was several times higher (0.87 ± 0.05 GAE/g to 2.38 ± 0.08 GAE/g) than the extracts obtained from the mushroom grown on the synthetic (glycerol contained) nutrient medium (0.21 ± 0.03 GAE/g to 0.88 ± 0.05 GAE/g). Flavonoid contents in the extracts from Sch. commune varied from 0.58 ± 0.03 to 27.2 ± 0.8 mg QE/g. Identification of phenolic compounds composition in water and ethanol extracts were provided by mass spectrometry analysis. Extracts demonstrate considerable free radical scavenging activities and the IC50 values were generally low for the extracts, ranging from 1.9 mg/ml to 6.7 mg/ml. All the samples displayed a positive correlation between their concentration (0.05-15.0 mg/ml) and DPPH radical scavenging activity. This investigation revealed that Sch. commune mushroom has great potential to be used as a source of antifungal and antioxidant substances.

Lectin activity of species of genus Cerrena S.F. Gray (Aphyllophoromycetideae) in submerged fermentation of lignocellulosic materials.

The capability of 5 strains of 2 species of genus Cerrena (Aphyllophoromycetideae) to express hemagglutinating activity (HA) was evaluated in submerged fermentation of 7 lignocellulosic materials of different chemical compositions. Among the lignocellulosic substrates tested, walnut pericarp, followed by mandarin and kiwi peels provided the highest specific HA of C. unicolor IBB 300; walnut leaves and pericarp appeared to be the best substrates for the accumulation of lectin by C. unicolor IBB 301, whereas the fermentation of kiwi peels ensured the highest HA of C. unicolor IBB 302. The highest HA was detected in C. maxima IBB 402 cultivation in submerged fermentation of walnut leaves (64103 U/mg), mandarin (33333 U/mg) and kiwi peels (28571 U/mg). Moreover, the fermentation of walnut pericarp and leaves provided the secretion of high lectin levels in culture liquid (9143 U/mg). The carbohydrate specificity of tested preparations significantly depended on both fungus strain and lignocellulosic growth substrate. By substitution of lignocellulosic material, it is possible to regulate lectin production and to obtain a preparation with different specificity toward carbohydrates.

Effect of aromatic compounds on the production of laccase and manganese peroxidase by white-rot basidiomycetes.

Three white-rot fungi displayed a wide diversity in their response to supplemented aromatic compounds. Pyrogallol stimulated Cerrena unicolor laccase and manganese peroxidase (MnP) synthesis in synthetic medium 2.5- and 2-fold, respectively, whereas 2,4,6-trinitrotoluene (TNT) brought about a 2.8-fold increase in laccase yield by Trametes versicolor in submerged fermentation of ethanol production residue. No effect of the tested aromatic compounds on enzyme secretion by Ganoderma lucidum in mannitol-containing medium was detected. Nevertheless, G. lucidum is a potent producer of laccase in submerged fermentation of wheat bran and enzyme synthesis can be further increased by supplementation of medium with an appropriate inducer. The structure and the concentration of aromatic compounds play an important role in the regulation of enzyme synthesis. The supplementation of synthetic medium with 0.03-0.3 mM TNT or hydroquinone increased the differential rate of laccase synthesis by C. unicolor from 1,267 to 3,125-8,630 U mg biomass(-1) day(-1). Moreover, the same aromatic compound may function as either an inducer or a repressor, depending on the fungus and enzyme studied. Thus, hydroquinone increased 3-fold T. versicolor laccase activity decreasing 2- and 8-fold the yields of MnP and endoglucanase, respectively.

Elucidation of the Higher Basidiomycetes Enzyme Activity in Dependence on the Medicinal Mushroom Inoculum Form, Precultivation Medium, Age, and Size.

The impact of five mushroom inoculum form, age, size, and precultivation medium on the lignocellulose-deconstracting enzyme (LCDE) production was evaluated in the submerged fermentation of mandarin marc. The results obtained evidence that an adaptation of individual fungi to lignocellulose during maintenance in culture collection and inoculum cultivation may be useful for the production of individual LCDE. Homogenization of submerged mycelium was beneficial for all LCDE production by Cerrena unicolor 305 and Ganoderna lucidum 447 and for LME secretion by Coriolopsis gallica 142 and Trametes multicolor 511. Finely chopped mycelial agar favored CMCase and xylanase production by T. multicolor 511 and LiP secretion by C. unicolor 305 and G. lucidum 447 while homogenized mycelial agar proved to be the worst form of inoculum for the production of most enzymes. Four-days inoculum was the most appropriate for the laccase and MnP production by G. lucidum 447 and T. multicolor 511 while the 7-days mycelium provided the highest yields of these enzymes in the cultivation of C. unicolor 305. Use of the 12-days homogenized mycelium from the late stationary phase resulted in lowest laccase activity of all fungi but provided the highest cellulase activity. Overall, the study showed that the LCDE activity and their accumulation profiles in the cultures with different inoculum size was species dependent.

Recent Advances in the Physiology of Spore Formation for Bacillus Probiotic Production.

Spore-forming probiotic bacteria have received a wide and constantly increasing scientific and commercial interest. Among them, Bacillus species are the most studied and well-characterized Gram-positive bacteria. The use of bacilli as probiotic products is expanding especially rapidly due to their inherent ability to form endospores with unique survivability and tolerance to extreme environments and to produce a large number of valuable metabolites coupled with their bio-therapeutic potential demonstrating immune stimulation, antimicrobial activities and competitive exclusion. Ease of Bacillus spp. production and stability during processing and storage make them a suitable candidate for commercial manufacture of novel foods or dietary supplements for human and animal feeds for livestock, especially in the poultry and aquaculture industries. Therefore, the development of low-cost and competitive technologies for the production of spore-forming probiotic bacteria through understanding physiological peculiarities and mechanisms determining the growth and spore production by Bacillus spp. became necessary. This review summarizes the recent literature and our own data on the physiology of bacilli growth and spore production in the submerged and solid-state fermentation conditions, focusing on the common characteristics and unique properties of individual bacteria as well as on several approaches providing enhanced spore formation.

Comparison of Mono- and Dikaryotic Medicinal Mushrooms Lignocellulolytic Enzyme Activity.

Mono- and dikaryotic medicinal mushroom strains isolated from four wood-rotting basidiomycete fruiting bodies were comparatively evaluated for laccase, manganese peroxidase, cellulase, and xylanase activities in submerged cultivation in glucose or mandarin peel-containing media. Mandarin peels appeared to be the preferred growth substrate for laccase production by both mono- and dikaryotic Trametes multicolor 511 and T. versicolor 5 while glucose favored laccase activity secretion by Pleurotus ostreatus 2175. Lignocellulose-deconstructing enzyme profiles were highly variable between the studied monokaryotic and dikaryotic strains. A distinctive superiority of enzyme activity of the dikaryotic Trametes versicolor 5 and P. ostreatus 2175 over the same species monokaryotic isolates was revealed. By contrast, laccase, cellulase, and xylanase activities of the monokaryotic strain of T. multicolor 511 were rather higher than those in the dikaryotic culture. At the same time, hydrolases activity of Schizophyllum commune 632 was practically independent of the origin of the fungal culture. The results suggest that the monokaryotic isolates derived from the basidiomycetes fruiting bodies inherit parental properties but the capacity of individual monokaryotic cultures to produce lignocellulose-deconstructing enzymes can vary considerably.

Lentinus edodes and Pleurotus species lignocellulolytic enzymes activity in submerged and solid-state fermentation of lignocellulosic wastes of different composition.

Lentinus edodes and Pleurotus species from various origins were compared for the first time for their ability to produce lignocellulolytic enzyme in solid-state (SSF) and submerged (SF) fermentation of various plant raw material. Fungi cultivation in identical culture conditions revealed wide differences among both species and strains of the same species. The yields of CMCase (62.3Uml(-1)), xylanase (84.1 U ml(-1)), FPA (5.9 U ml(-1)), and laccase (4103 Ul(-1)) are the best so far obtained with the strains of oyster mushrooms. The study pointed out that the nature of lignocellulosic material and the method of fungi cultivation are factors determining the expression of lignocellulolytic potential of fungi as well as the ratio of individual enzymes in enzyme complex. SSF of tree leaves is favorable for laccase and MnP secretion by the majority L. edodes and Pleurotus strains, whereas SF provides better production of hydrolytic enzymes.

Evaluation of Lignin-Modifying Enzyme Activity of Trametes spp. (Agaricomycetes) Isolated from Georgian Forests with an Emphasis on T. multicolor Biosynthetic Potential.

In this study, a wide diversity in lignin-modifying enzyme (LME) secretion by 11 Trametes spp. strains isolated from the forests of Georgia was revealed in their submerged cultivation in both synthetic and lignocellulose-based media. Among them, T. multicolor BCC 511 was distinguished by simultaneous production of laccase, manganese peroxidase (MnP), and lignin peroxidase (LiP) in the presence of high carbon and nitrogen concentrations. Mannitol at the concentration of 15 g/L provided an accumulation of 23.7 U/mL laccase and 0.56 U/mL MnP. Significant modulation of LME activity by lignocellulosic substrates, metals, aromatic compounds, and their concentrations was established. Mandarin peels manifold increased the fungus laccase and LiP activities, while the ethanol production residue and banana peels activated manganese-oxidizing and Phenol Red-oxidizing manganese peroxidases, respectively. The addition of 2 mM of copper sulfate to the control medium induced the laccase production 28-fold and did not significantly affect the MnP and LiP activities. Fe2+ at a concentration of 0.1 mM enhanced the fungus volumetric and specific laccase activities almost 8-fold; at a concentration of 0.25-0.5 mM, there was a 2-fold increase in the MnP activity. Mn2+ appeared to be an effective inducer of the Mn-oxidizing MnP, increasing specific activity of the enzyme 14-fold. Supplementation of the copper-containing medium with 1 mM veratryl alcohol or guaiacol favored laccase and MnP production. The high yields of laccase (110 U/mL), MnP (0.62 U/mL), and LiP (0.71 U/mL) obtained in a laboratory fermenter make T. multicolor 511 useful for industrial and environmental applications.

Bacillus amyloliquefaciens Spore Production Under Solid-State Fermentation of Lignocellulosic Residues.

This study was conducted to elucidate cultivation conditions determining Bacillus amyloliquefaciens B-1895 growth and enhanced spore formation during the solid-state fermentation (SSF) of agro-industrial lignocellulosic biomasses. Among the tested growth substrates, corncobs provided the highest yield of spores (47 × 1010 spores g-1 biomass) while the mushroom spent substrate and sunflower oil mill appeared to be poor growth substrates for spore formation. Maximum spore yield (82 × 1010 spores g-1 biomass) was achieved when 15 g corncobs were moistened with 60 ml of the optimized nutrient medium containing 10 g peptone, 2 g KH2PO4, 1 g MgSO4·7H2O, and 1 g NaCl per 1 l of distilled water. The cheese whey usage for wetting of lignocellulosic substrate instead water promoted spore formation and increased the spore number to 105 × 1010 spores g-1. Addition to the cheese whey of optimized medium components favored sporulation process. The feasibility of developed medium and strategy was shown in scaled up SSF of corncobs in polypropylene bags since yield of 10 × 1011 spores per gram of dry biomass was achieved. In the SSF of lignocellulose, B. amyloliquefaciens B-1895 secreted comparatively high cellulase and xylanase activities to ensure good growth of the bacterial culture.

Alteration of white-rot basidiomycetes cellulase and xylanase activities in the submerged co-cultivation and optimization of enzyme production by Irpex lacteus and Schizophyllum commune.

Mono and dual cultures of four white-rot basidiomycete species were evaluated for cellulase and xylanase activity under submerged fermentation conditions. Co-cultivation of Pycnoporus coccineus or Trametes hirsuta with Schizophyllum commune displayed antagonistic interactions resulting in the decrease of endoglucanase and total cellulase activities. In contrast, increases in cellulase and xylanase activity were revealed through the compatible interactions of Irpex lacteus with S. commune. Co-cultivation conditions were optimized for maximum enzyme production by I. lacteus and S. commune, the best producers of cellulase/xylanase and ß-glucosidase, respectively. An optimized medium for the target enzyme production by the mixed culture was established in a laboratory fermenter yielding 7U/mL total cellulase, 142U/mL endoglucanase, 104U/mL xylanase, and 5.2U/mL ß-glucosidase. The dual culture approach resulted in an enzymatic mixture with 11% improved lignocellulose saccharification potential compared to enzymes from a monoculture of I. lacteus.

Physiological Peculiarities of Lignin-Modifying Enzyme Production by the White-Rot Basidiomycete Coriolopsis gallica Strain BCC 142.

Sixteen white-rot Basidiomycota isolates were screened for production of lignin-modifying enzymes (LME) in glycerol- and mandarin peel-containing media. In the synthetic medium, Cerrena unicolor strains were the only high laccase (Lac) (3.2-9.4 U/mL) and manganese peroxidase (MnP) (0.56-1.64 U/mL) producers while one isolate Coriolopsis gallica was the only lignin peroxidase (LiP) (0.07 U/mL) producer. Addition of mandarin peels to the synthetic medium promoted Lac production either due to an increase in fungal biomass (Funalia trogii, Trametes hirsuta, and T. versicolor) or enhancement of enzyme production (C. unicolor, Merulius tremellosus, Phlebia radiata, Trametes ochracea). Mandarin peels favored enhanced MnP and LiP secretion by the majority of the tested fungi. The ability of LiP activity production by C. gallica, C. unicolor, F. trogii, T. ochracea, and T. zonatus in the medium containing mandarin-peels was reported for the first time. Several factors, such as supplementation of the nutrient medium with a variety of lignocellulosic materials, nitrogen source or surfactant (Tween 80, Triton X-100) significantly influenced production of LME by a novel strain of C. gallica. Moreover, C. gallica was found to be a promising LME producer with a potential for an easy scale up cultivation in a bioreactor and high enzyme yields (Lac-9.4 U/mL, MnP-0.31 U/mL, LiP-0.45 U/mL).

Elucidation of Bacillus subtilis KATMIRA 1933 Potential for Spore Production in Submerged Fermentation of Plant Raw Materials.

In this study, the effects of several key factors to increase spore production by Bacillus subtilis subsp. KATMIRA 1933 were evaluated in shake flask experiments. In a synthetic medium, glucose concentration played a crucial role in the expression of bacilli sporulation capacity. In particular, maximum spore yield (2.3 × 109 spores/mL) was achieved at low glucose concentration (2 g/L), and further gradual increase of the carbon source content in the medium caused a decrease in sporulation capacity. Substitution of glucose with several inexpensive lignocellulosic materials was found to be a reasonable way to achieve high cell density and sporulation. Of the materials tested, milled mandarin peels at a concentration of 40 g/L served as the best growth substrate. In these conditions, bacilli secreted sufficient levels of glycosyl hydrolases, providing slow hydrolysis of the mandarin peel's polysaccharides to metabolizable sugars, providing the bacterial culture with an adequate carbon and energy source. Among nitrogen sources tested, peptone was found to favor spore production. Moreover, it was shown that cheese and cottage cheese whey usage, instead of distilled water, significantly increases spore formation. After optimization of the nutrient medium in the shake flask experiments, the technical feasibility of large-scale spore production by B. subtilis KATMIRA 1933 was confirmed in a laboratory fermenter. The spore yield (7 × 1010 spores/mL) obtained using a bioreactor was higher than those previously reported.

Trinitrotoluene and mandarin peels selectively affect lignin-modifying enzyme production in white-rot basidiomycetes.

Five white-rot basidiomycetes (WRB) species have been evaluated for their potential to tolerate and to degrade 0.2 mM 2, 4, 6-trinitrotoluene (TNT) as well as to produce laccase and manganese peroxidase (MnP) in presence of this xenobiotic. The tested fungal strains produced laccase in both glycerol and mandarin peels-containing media, whereas in the glycerol-containing medium only Cerrena unicolor strains and Trametes versicolor BCC 775 secreted MnP. Replacement of glycerol by milled mandarin peels 3- to 45-fold increased laccase activity, promoted C. unicolor strains and T. versicolor MnP secretion and induced this enzyme production by Fomes fomentarius BCC 38 and Funalia trogii BCC 146. Differential response of the WRB strains to the TNT addition was observed. In particular, laccase activity of C. unicolor increased 2- to 3-fold in both media whereas no stimulation of the laccase production was revealed in cultivation of F. fomentarius. TNT practically did not affect the MnP activity. Two strains of C. unicolor followed by T. versicolor producing laccase and MnP almost completely removed 0.2 mM TNT from the synthetic medium. Increase of TNT concentration from 0 to 0.4 mM in the mandarin peels-based medium and from 0 to 0.3 mM in the glycerol-containing medium stimulated C. unicolor BCC 300 laccase production from 92.4 to 240.7 U/ml and from 17.1 to 48.6 U/ml, respectively. This strain has been resistant to the TNT high concentration and has ability to remove 85 % of initial 0.3 mM TNT content during 6 days of the submerged cultivation.

Shiitake Medicinal Mushroom, Lentinus edodes (Higher Basidiomycetes) Productivity and Lignocellulolytic Enzyme Profiles during Wheat Straw and Tree Leaf Bioconversion.

Two commercial strains of Lentinus edodes have been comparatively evaluated for their productivity and lignocellulolytic enzyme profiles in mushroom cultivation using wheat straw or tree leaves as the growth substrates. Both substrates are profitable for recycling into shiitake fruit bodies. L. edodes 3715 gave the lowest yield of mushroom during tree leaves bioconversion with the biological efficiency (BE) 74.8% while the L. edodes 3721 BE achieved 83.4%. Cultivation of shiitake on wheat straw, especially in the presence of additional nitrogen source, increased the L. edodes 3721 BE to 92-95.3% owing to the high hydrolases activity and favorable conditions. Despite the quantitative variations, each strain of L. edodes had a similar pattern for secreting enzymes into the wheat straw and tree leaves. The mushrooms laccase and MnP activities were high during substrate colonization and declined rapidly during primordia appearance and fruit body development. While oxidase activity decreased, during the same period cellulases and xylanase activity raised sharply. Both cellulase and xylanase activity peaked at the mature fruit body stage. When mushrooms again shifted to the vegetative growth, oxidase activity gradually increased, whereas the hydrolases activity dropped rapidly. The MnP, CMCase, and FP activities of L. edodes 3721 during cultivation on wheat straw were higher than those during mushroom growth on tree leaves whereas the laccase activity was rather higher in fermentation of tree leaves. Enrichment of wheat straw with an additional nitrogen source rather favored to laccase, MnP, and FPA secretion during the vegetative stage of the L. edodes 3721 growth.

Isolation and Characterization of Lectins Formed by Cerrena unicolor (Higher Basidiomycetes) in Solid-State Fermentation of Sorghum and Wheat Straw.

The capability of Cerrena unicolor to produce fruiting bodies and lectins was studied in solid-state fermentation of a sorghum and wheat straw mixture. The first primordia appeared on day 48 and reached 6-10 mm; however, no formation of fruiting bodies occurred and these rudiments were harvested on day 55. The protein content in the rudiment extracts was significantly higher, whereas the specific hemagglutinating activity (HA) was sixfold lower as compared with those in extracts from mycelial biomass. Moreover, the specific HA of the 80-day mycelium increased to 16,667 U/mg, exceeding by sixfold that of 55-day-old mycelium. Four protein fractions (160, 105, 67, and 8 kDa) were detected by gel-chromatography of mycelial biomass crude extract; the highest specific HA was revealed in fraction III (26336 U HA/mg). Among sugars tested, galactose was the most potent inhibitor of HA of all protein fractions, with minimal inhibition concentrations of 0.095-0.780 mM. The galactose-specific lectins isolated from the fractions II and III by affinity chromatography ranged from 15 to 116 kDa and differed with kinetic parameters.

Modulation of Cerrena unicolor laccase and manganese peroxidase production.

Among seven carbon sources tested, glycerol and glucose favored the Cerrena unicolor laccase production (18.8-20.3 U/mL); in addition, glycerol ensured the highest manganese peroxidase (MnP) activity (2 U/mL). Substitution of glycerol with the ethanol production residue (EPR) gave the highest laccase (90.1 U/mL) activity, while the walnut pericarp provided the highest MnP activity (7.4 U/mL). Supplementation of medium with 1 mM copper and 1 mM xylidine at appropriate time caused significant additive effect on laccase expression (333.2 U/mL) in shake-flask experiments. Overproduction of laccase activity (507 U/mL) and secretion of MnP activity was obtained when C. unicolor was cultivated in stirred-tank fermenter. C. unicolor showed several distinctive and attractive technological features: it is capable to synthesize high levels of oxidases under high carbon and high nitrogen conditions and it secretes high laccase activity during trophophase.

Physiological regulation of laccase and manganese peroxidase production by white-rot Basidiomycetes.

This review integrates recent literature and our own data on the physiology of laccase and manganese peroxidase synthesis, focusing on the common characteristics and unique properties of individual fungi as well as on several approaches providing enhanced enzyme secretion. Firstly, the enzyme yield is species-dependent and strain-dependent and selection of new organisms with tremendous synthesis of these enzymes is possible. For example, in screening program the laccase activity of tested basidiomycetes varied from 0.5Uml(-1) to 75Uml(-1). Secondly, the carbon source and lignocellulosic substrate play a crucial role in enzyme production. Thus, laccase activity of Pseudotrametes gibbosa varied from 0.3Uml(-1) (Avicel) to 13.7Uml(-1) (lactose), while the substitution of wheat bran with walnut pericarp increased Cerrena unicolor manganese peroxidase yield from 0.7Uml(-1) to 8.3Uml(-1). Thirdly, aromatic compounds regulate the ligninolytic enzyme synthesis although their effect is very specific depending on fungi physiological peculiarities. 2,4,6-trinitrotoluene (TNT) supplemented to the medium at appropriate concentration significantly accelerated C. unicolor laccase production and 4-fold increased laccase specific activity. Fourthly, co-cultivation of appropriate fungi shows considerable promise as a strategy to highly enhance the enzyme production. For example, pairing of C. unicolor and Phellinus robustus 2-fold increased the total laccase yield.

Effect of growth substrate, method of fermentation, and nitrogen source on lignocellulose-degrading enzymes production by white-rot basidiomycetes.

The exploration of seven physiologically different white rot fungi potential to produce cellulase, xylanase, laccase, and manganese peroxidase (MnP) showed that the enzyme yield and their ratio in enzyme preparations significantly depends on the fungus species, lignocellulosic growth substrate, and cultivation method. The fruit residues were appropriate growth substrates for the production of hydrolytic enzymes and laccase. The highest endoglucanase (111 U ml(-1)) and xylanase (135 U ml(-1)) activities were revealed in submerged fermentation (SF) of banana peels by Pycnoporus coccineus. In the same cultivation conditions Cerrena maxima accumulated the highest level of laccase activity (7,620 U l(-1)). The lignified materials (wheat straw and tree leaves) appeared to be appropriate for the MnP secretion by majority basidiomycetes. With few exceptions, SF favored to hydrolases and laccase production by fungi tested whereas SSF was appropriate for the MnP accumulation. Thus, the Coriolopsis polyzona hydrolases activity increased more than threefold, while laccase yield increased 15-fold when tree leaves were undergone to SF instead SSF. The supplementation of nitrogen to the control medium seemed to have a negative effect on all enzyme production in SSF of wheat straw and tree leaves by Pleurotus ostreatus. In SF peptone and ammonium containing salts significantly increased C. polyzona and Trametes versicolor hydrolases and laccase yields. However, in most cases the supplementation of media with additional nitrogen lowered the fungi specific enzyme activities. Especially strong repression of T. versicolor MnP production was revealed.

Lignocellulolytic enzymes profile during growth and fruiting of Pleurotus ostreatus on wheat straw and tree leaves.

Cultivation of two commercial Pleurotus ostreatus (oyster mushroom) strains was performed in plastic bags. Tree leaves appeared to be an excellent growth substrate for the conversion into fruiting bodies with biological efficiency of 108-118%. The level of enzyme activity was strongly regulated during the life cycle of mushrooms. However, despite the quantitative variations, each strain had a similar pattern of enzyme accumulation in fermentation of both substrates. Laccase and MnP activities were high during substrate colonization and declined rapidly during fruiting body development. On the contrary, in substrate colonization P. ostreatus expressed comparatively low activity of hydrolases. When primordia appeared, the activity of these enzymes sharply increased. Both cellulase and xylanase activity peaked at the mature fruiting body stage. When mushrooms shifted to the vegetative growth, the activity of ligninolytic enzymes again gradually increased, whereas the activity of hydrolases decreased.