The role of laccase and peroxidase of Lentinus (Panus) tigrinus fungus in biodegradation of high phenol concentrations in liquid medium

The possibility of the usage of Lentinus tigrinus fungus strain VKM F-3616D for biodegradation of high (up to 5%) phenol concentrations in liquid medium and the involvement of laccase and peroxidase in this process have been studied. L. tigrinus fungus was demonstrated to effectively digrade phenol with easy biomass separation from the liquid. Decrease in phenol concentration was accompanied by increased secretion level and laccase activity at the preliminary stages of biodegradation, while that of peroxidase was at the latest stages of biodegradation. These enzyme secretions in distinct ratios and consequences are necessary for effective phenol biodegradation. An effective approach for phenol concentration decrease in the waste water of smoking shops in meat-processing factories using L. tigrinus fungus was described.     

Effect of wood modification on lignin consumption and synthesis of lignolytic enzymes by the fungus Panus (Lentinus) tigrinus

Lignin consumption and synthesis of lignolytic enzymes by the fungus Panus (Lentinus) tigrinus cultivated on solid phase (modified and unmodified birch and pine sawdusts) were studied. The fungus grew better and consumed more readily the birch lignin than the pine wood. Peroxidase activity was higher in the case of pine sawdust; laccase and lignolytic activities, in the case of birth sawdust. Treatment with ammonia or sulfuric acid decreased lignin consumption by the fungus cultivated on either medium. Modification of sawdust by ultrasound increased lignin consumption and may be recommended for accelerating biodegradation of lignocellulose substrates.     

Modification of wood lignin by the fungus Panus tigrinus

The treatment of sawdust with the fungus Panus tigrinus VKM F-3616 D changed the contents of functional groups in lignin from wood raw material. These changes are accompanied by the release of carboxyl and phenyl hydroxyl groups involved in chemical bond formation between wood particles in pressed materials manufactured from wood wastes.     

Submerged and solid-state production of laccase and Mn-peroxidase by Panus tigrinus on olive mill wastewater-based media

The possible use of olive-mill wastewater (OMW) as a growth medium for the production of extracellular laccase and manganese peroxidase (MnP) from the white-rot fungus Panus tigrinus (P. tigrinus) CBS 577.79 was studied using a properly formulated OMW-based medium (2-fold diluted OMW supplemented with 0.5% sucrose and 0.1% yeast extract) either in a stirred-tank or an air-lift reactor. Solid-state fermentation (SSF) was also performed in a rotary drum reactor using maize stalks moistened with the OMW-based medium. Highest levels of laccase and manganese peroxidase activity were obtained in the stirred-tank reactor (4600+/-98 U l(-1) on day 13) and in the air-lift reactor (410+/-22 on day 7), respectively. Based on total enzyme activities, SSF appears to be more suitable than LSF but the latter exhibits better volumetric productivities.     

Isolation and properties of peroxidase produced by the fungus Panus tigrinus

Synthesis of peroxidase and laccase by the fungus Panus tigrinus was significantly stimulated by addition of the lignocellulose substrate to the culture media. Peroxidase was isolated from the culture liquid and some properties of the enzyme were investigated. P. tigrinus peroxidase belongs to a group of extracellular peroxidases similar to the plant type peroxidases.     

Effect of Wood Modification on Lignin Consumption and Synthesis of Lignolytic Enzymes by the Fungus Panus (Lentinus) tigrinus

Lignin consumption and synthesis of lignolytic enzymes by the fungus Panus (Lentinus) tigrinuscultivated on solid phase (modified and unmodified birch and pine sawdusts) were studied. The fungus grew better on and consumed more readily the birch lignin than the pine wood. Peroxidase activity was higher in the case of pine sawdust; laccase and lignolytic activities, in the case of birth sawdust. Treatment with ammonia or sulfuric acid decreased lignin consumption by this fungus cultivated on either medium. Modification of sawdust by ultrasound increased lignin consumption and may be recommended for accelerating biodegradation of lignocellulose substrates.     

New ways to increasing the yield of laccase from Panus tigrinus fungi

We optimized the conditions for production of laccase by lignolytic fungi Panus tigrinus 8/18. 2,4-Dimethylphenol was used as an aromatic inductor. The addition of 2,4-dimethylphenol and 2 mM CuSO4 to a rich medium was followed by a tenfold increase in the yield of this enzyme. Additional treatment of the medium with perftoran (oxygen-carrying agent) and immobilization of the fungus on polycaproamide fibers increased significantly laccase activity in the medium. The conditions for cultivation of P. tigrinus fungi were optimized. It allowed us to increase laccase activity in the medium by 25 times (compared to activity of the enzyme obtained with previously described methods).     

Wood Lignin Modification by the Fungus Panus tigrinus

The treatment of sawdust with the fungus Panus tigrinus VKM F-3616 D changed the contents of functional groups in lignin from wood raw material. These changes are accompanied by the release of carboxyl and phenyl hydroxyl groups involved in chemical bond formation between wood particles in pressed materials manufactured from wood wastes.     

Relation between ligninolytic and phospholipase activities in the fungus Lentinus tigrinus

Effect of hydrocortisone, NaF, and FeSO₄ on ligninolytic and phosphatase activity of the fungus Lentinus (Panus) tigrinus VKM F-3616D was investigated. Hydrocortisone and NaF were shown to inhibit the enzymes of the ligninolytic complex—laccase (EC 1.10.3.2), secretory peroxidase (EC 1.11.1.7), and Mn peroxidase (EC 1.11.1.13). FeSO₄ exhibited no significant effect on the activity of these enzymes. Decreased activity of the enzymes of the ligninolytic complex was associated with inhibition of the activity and changes in the substrate specificity of phospholipase A₂ (EC 3.1.1.4) in the presence of hydrocortisone of NaF. Cultivation of L. tigrinus in the presence of these compounds resulted in higher affinity of this enzyme to saturated fatty acids, while in the control and in the presence of FeSO₄ affinity to unsaturated fatty acids was higher.     

Interrelation between the composition of lipids and their peroxidation products and the secretion of ligninolytic enzymes during growth of Lentinus (Panus) tigrinus

Lipid composition, intracellular products of lipid peroxidation (LPO), and the activities of extracellular enzymes were studied during submerged cultivation of the xylotrophic fungus Lentinus (Panus) tigrinus VKMF-3616D. The maximum secretion of ligninolytic enzymes during the phase of active mycelium growth correlated with increased content of readily oxidized phospholipids and unsaturated fatty acids and with low content of the LPO products. In the idiophase, which was characterized by lower excretion of extracellular ligninolytic enzymes, the content of more stable phospholipids, saturated fatty acids, and LPO products increased. A relationship between the composition of mycelial lipids and the secretion of ligninolytic enzymes was revealed.     

Effect of agitation and aeration on the reduction of pollutant load of olive mill wastewater by the white-rot fungus Panus tigrinus

The white-rot fungus Panus tigrinus CBS 577.79 was cultivated both in mechanical (stirred tank, STR) and pneumatically (bubble column, BCB) agitated bioreactors and investigated for its ability to reduce the polluting load of olive-mill wastewater (OMW). Both aeration and agitation strongly influenced treatment efficiency. Best pollutants biodegradation performances were achieved in the bubble column bioreactor. Using this bioreactor, COD reduction, dephenolization and decoloration were 60.9, 97.2 and 75%, respectively. In contrast, lower depollution efficiency was generally observed in STR due to the possible occurrence of shear stress.     

Interrelation between the composition of lipids and products of their peroxidation and the secretion of ligninolytic enzymes during growth of Lentinus (Panus) tigrinus

Lipid composition, intracellular products of lipid peroxidation (LPO), and the activities of extracellular enzymes were studied during submerged cultivation of the xylotrophic fungus Lentinus (Panus) tigrinus VKM F-3616D. The maximum secretion of ligninolytic enzymes during the phase of active mycelium growth correlated with increased content of readily oxidized phospholipids and unsaturated fatty acids and with low content of the LPO products. In the idiophase, which was characterized by lower excretion of extracellular ligninolytic enzymes, the content of more stable phospholipids, saturated fatty acids, and LPO products increased. A relationship between the composition of mycelial lipids and the secretion of ligninolytic enzymes was revealed.     

Uptake of cadmium ions in white-rot fungus Trametes versicolor: effect of cd (II) ions on the activity of laccase

The effects of cadmium Cd (II) ions on the physiology and biological activity of Trametes versicolor, a strain belonging to white-rotting Basidiomycetes, were examined. Cd (II) ions were added to 10-day-old cultures grown on a liquid medium, or at the time of inoculation. Our experiments showed that T. versicolor is a good cadmium biosorbent from aqueous solution, this strain removing almost all the Cd (ll) ions over the first 2h of incubation by what appears to be a rapid, energy-independent surface binding phenomenon, at the rate of approximately 2mg Cd per g mycelial dry weight. An additional slower and energy-dependent transport mechanism was also present, taking in approximately 0.3mg Cd (II) perg dry weight. It is also shown that these Cd (II) ions significantly stimulate the activity of extracellular laccase when added to 10-day-old cultures.     

The character of endogenous growth regulators in the course of development in the fungus Lentinus tigrinus

The character of endogenous growth regulators in different stages of growth and development ofLentinus tigrinus was followed by means of bioassays. The methanolic extract of differently old mycelium and fruiting body was chromatographically separated and tested for auxins by means of Avena coleoptile segments, for gibberellins by using lettuce seedlings and for cytokinins by measuring the content of chlorophyl in leaf segments of barley. Auxins were found only in young vegetative mycelium and in the growing young stalk. The level of gibberellins is more significant and it reaches the highest values in the vegetative mycelium, in the growing young stalk and in the differentiated cap. The content of auxin and gibberellin substances did not increase even in the medium after cultivation of mycelium. Bioassays of cytokinins show a slight stimulation in the vegetative mycelium and in the primordia of caps. Significant inhibition was ascertained in the fully developed stalk. The high quantities of cytokinins were found in caps when basidiospores were formed. The results show a close connection of endogenous growth substances with the growth and the development of the fungus and indicate their participation in differentiation processes.     

The role of laccase and peroxidase of <Emphasis Type=Italic>Lentinus (Panus) tigrinus</Emphasis> fungus in biodegradation of high phenol concentrations in liquid medium

The possibility of the usage of Lentinus tigrinus fungus strain VKM F-3616D for biodegradation of high (up to 5%) phenol concentrations in liquid medium and the involvement of laccase and peroxidase in this process have been studied. L. tigrinus fungus was demonstrated to effectively degrade phenol with easy biomass deletion from the liquid. Decrease in phenol concentration was accompanied by increased secretion level and laccase activity at the preliminary stages of biodegradation, while that of peroxidase was at the latest stages of biodegradation. These enzyme secretions in distinct ratios and consequences are necessary for effective phenol biodegradation. An effective approach for phenol concentration decrease in the waste water of smoking shops in meat-processing factories using L. tigrinus fungus was described.     

Effect of nutrient nitrogen and manganese on manganese peroxidase and laccase production by Lentinula (Lentinus) edodes

Abstract Lentinula (Lentinus) edodes , strain LS4, produces manganese-dependent peroxidase (MnP) and laccase, but not lignin peroxidase, when grown on a defined medium with glucose as sole carbon source. MnP production is suppressed by nitrogen whereas highest levels of laccase were observed when the fungus was grown under high nitrogen (26 mM) conditions. Both the titre and time of appearance of MnP were affected by the concentration of Mn in the culture medium with highest enzyme levels recorded in cultures supplemented with 1.1 ppm Mn. Purified MnP from L. edodes LS4 has an apparent M _r of 59000 and a p I of 5.6, and differs in several respects from a MnP isolated from L. edodes grown on a commercial wood substrate.     

Influence of lignin and oxygen on the growth and the lipid formation of the fungus Lentinus tigrinus

During cultivation of the filamentous fungus Lentinus tigrinus on a medium containing lignin, a high oxygen content stimulated the growth of the fungus and contributed to the yield of lipids. A high content of phosphatidic acid and a reduction in the level of phosphatidylethanolamine and phosphatidylserine were first detected in the composition of phospholipids. Changes in the composition of neutral lipids, such as variation in the ratio of esterified and free sterols, have occurred; thus, the amount of sterol esters reduced simultaneously with a decrease in the content of free fatty acids. Based on the obtained results, the possible role of phosphatidic acid as a second messenger in the process of the consumption of lignin by the fungus Lentinus tigrinus is discussed.     

Effect of culturing processes and copper addition on laccase production by the white-rot fungus Fomes fomentarius MUCL 35117

Aim:  To produce high laccase activities from the white-rot fungus Fomes fomentarius .
Methods and Results:  Different culturing methods, viz, cell immobilization on stainless steel sponges and plastic material and solid-state fermentation (SSF) using wheat bran as substrate were used for laccase production by the white-rot fungus F. fomentarius . The SSF study expresses the highest laccase activities, nearly to 6400 U l⁻¹ after 13 days of laboratory flasks cultivation. When the wheat bran medium was supplemented with 2 mmol l⁻¹ copper sulfate, laccase activity increased by threefold in comparison to control cultures, reaching 27 864 U l⁻¹. With the medium thus optimized, further experiments were performed in a 3 l fixed-bed bioreactor (working volume 1·5 l) leading to a laccase activity of about 6230 U l⁻¹ on day 13.
Conclusions:  The results obtained clearly showed the superiority of wheat bran for laccase production over stainless steel sponges and plastic material. Supplementing the wheat bran solid medium with 2 mmol l⁻¹ copper sulfate allowed obtaining high activities at flask scale. The system was scaled to fixed-bed laboratory reactor.
Significance and Impact of the Study:  The high enzyme production along with the low-cost of the substrate, showed the suitability of the system F. fomentarius – SSF for industrial purposes.     

Use of Panus tigrinus fungi for production of pressed materials from cotton plant waste

Changes in the chemical composition of cotton plant stems used as a substrate for solid-phase cultivation of the fungus Panus tigrinus were studied as well as the effect of these changes on properties of the pressed materials made of these stems. During the first 3 days of growth, the fungus better consumed cellulose; then, the rate of cellulose consumption was comparable with that of lignin. Intensity and pattern of these changes depended on the age of inoculum. The rate of cotton plant waste biodegradation was higher when a 3-day-old incoculum was used. The pressed materials made of the raw stuff treated with a 3-day-old inoculum of P. tigrinus for 2-3 days displayed better characteristics. Annually, large amounts of lignocellulose stuff is lost while processing of agricultural waste: straw, awn, plant stems, etc. In the countries with developed cotton growing, the annual amount of only guza-paya (dry cotton plant stems) reaches several million tons. To solve this problem, bioconversion of these wastes is studied to manufacture useful products and materials.