D. A. Kadimaliev

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.

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 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.

Increased Secretion of Lignolytic Enzymes by the Lentinus tigrinus Fungus after Addition of Butanol and Toluene in Submerged Cultivation

We studied the effects of butanol and toluene on secretion of lignolytic enzymes by the Lentinus tigrinus fungus during submerged cultivation. Addition of butanol and toluene during the trophophase was followed by an increase in laccase and peroxidase activity of the culture and change in the composition of phospholipids and fatty acids. The ratio of phosphatidylcholine and phosphatidic acid decreased, while the amount of lysophosphatidylcholine, phosphatidylethanolamine, phosphoinositides, phosphatidylserine, and unsaturated fatty acids decreased. These changes resulted in an increase in the unsaturation index.

Use of the Fungus Panus tigrinus in the Manufacture 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 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. The intensity and pattern of these changes depended on the age of the inoculum. The rate of cotton plant waste biodegradation was higher when a 3-day-old inoculum was used. Pressed materials made of the raw material treated with a 3-day-old inoculum of P. tigrinus for 2–3 days displayed better characteristics.

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.

Change in Phospholipid Composition and Phospholipase Activity of the Fungus Lentinus tigrinus VKM F-3616D during Growth in the Presence of Phenol and Lignocellulosic Substrates

Changes in phospholipid composition, phospholipase activity, and accumulation of lipid peroxidation products in mycelium of the lignindegrading fungus Lentinus (Panus) tigrinus VKM F-3616D in the presence of phenol and lignocellulosic substrates in the cultivation medium are reported. It is shown that in fungal mycelium in the presence of both substrates the share of lysophosphatidylcholine sharply increases. The parity between separate groups of phosphatidylinositols also changes. The lysophosphatidylcholine content increase during cultivation is connected with activation of phospholipase A2 (EC 3.1.1.4), and phosphatidylinositol parity change is associated with distinctions in affinity of phosphoinositidespecific phospholipase C (EC 3.1.4.11) to them.

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.

Wood Lignin Modification by the Fungus Panustigrinus

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.