[Degradation of the herbicide atrazine by the soil mycelial fungus INBI 2-26(-)--a producer of cellobiose dehydrogenase]. / Razlozhenie gerbitsida atrazina pochvennym mitselial'nym gribom INBI 2-26(-)--produtsentom tsellobiozodegidrogenazy.

Nonsporulating mycelial fungi producing cellobiose dehydrogenase (CDH) and isolated from soils of South Vietnam with high residual content of dioxins are capable of growing on a solid medium in the presence of high atrazine concentrations (to 500 mg/l). At 20 and 50 mg/l atrazine, the area of fungal colonies was 1.5-1.2-fold larger, respectively, compared with control colonies of the same age, whereas development of the colonies at 500 mg/l atrazine was delayed by 5 days, compared with controls grown in the absence of atrazine. Surface cultivation of the fungus on a minimal medium with glucose as a sole source of carbon and energy decreased the initial concentration of atrazine (20 mg/l) 50 times in 40 days; in addition, no pronounced sorption of atrazine by mycelium was detected. This was paralleled by accumulation in the culture medium of extracellular CDH; atrazine increased the synthesis of this enzyme two- to threefold. Accumulation of beta-glucosidase (a mycelium-associated enzyme) and cellulases preceded the formation of CDH.

[Fungal decomposition of oat straw during liquid and solid state fermentation]. / Razlozhenie ovsianoi solomy gribami pri zhidkofaznom i tverdofaznom kul'tivirovanii.

White rot fungi (Coriolus hirsutus, Coriolus zonatus, and Cerrena maxima from the collection of the Komarov Botanical Institute of the Russian Academy of Sciences) and filamentous fungi (Mycelia sterilia INBI 2-26 and Trichoderma reesei 6/16) were grown on oat straw-based liquid and solid media, as well as in a bench-scale reactor, either individually or as co-cultures. All fungi grew well on solid agar medium supplemented with powdered oat straw as the sole carbon source. Under these conditions, the mould Trichoderma reesei fully suppressed the growth of all basidiomycetes studied; conversely, Mycelia sterilia neither affected the development of any of the cultures, nor did it show any substantial susceptibility to suppression by their presence. Pure solid cultures of basidiomycetes, as well as the co-culture of Coriolus hirsutus and Cerrena maxima caused a notable bleaching of the oat straw during its consumption. When grown on the surface of oat straw-based liquid medium, the basidiomycetes consumed up to 40% polysaccharides without measurable lignin degradation (a concomitant process). Under these conditions, Mycelia sterilia decomposed no more than 25% lignin in 60 days, but this was observed only after polysaccharide exhaustion and biomass accumulation. In contrast, during solid state straw fermentation, white rot fungi consumed up to 75% cellulose and 55% lignin in 83 days (C. zonarus), whereas the corresponding consumption levels for co-cultures of Mycelia sterilia and Trichoderma reesei equaled 70 and 45%, respectively (total loss of dry weight ranged from 55 to 60%). Carbon dioxide-monitored solid-state fermentation of oat straw by the co-culture of filamentous fungi was successfully performed in an aerated bench-scale reactor.

[Effect of antioxidants on regeneration of protoplasts in the mycelial fungus Trichoderma reesei 6/16]. / Vliianie antioksidantov na regeneratsiiu protoplastov mitselial'nogo griba Trichoderma reesei 6/16.

The relative content of antioxidants in the mycelium of Trichoderma reesei 6/16 obtained by propagation of fungal protoplasts was shown to decrease (as compared to the initial culture taken for preparation of protoplasts) and restored only in the second generation of regenerated mycelium. In this respect, the effects of various antioxidants (beta-carotene, ascorbic acid, alpha-tocopherol, and ionol) on the frequency of regeneration of T. reesei 6/16 protoplasts were studied. beta-Carotene increased the viability of fungal protoplasts to the greatest extent. The effect of ascorbic acid depended on the presence of Fe ions. Ionol did not cause any measurable protective effect.

[Consumption of the triazine herbicide atrazine by laccase and laccase-free variants of the soil fungus Mycelia sterilia INBI-2-26]. / Potreblenie triazinovogo gerbitsida atrazina lakkaznym i bezlakkaznym variatami pochvennogo griba Mycelia sterilia INBI 2-26.

Asporogenic fungus Mycelia sterilia INBI 2-26 isolated from tropical soils with high residual dioxin content (as a result of Agent Orange defoliant treatment during the Vietnamese-American war) and capable of atrazine decomposition was treated to obtain protoplasts. This technique resulted in isolation of laccase-positive and laccase-negative clones. Atrazine consumption by liquid surface cultures of Mycelia sterilia INBI 2-26 was monitored by using enzyme immune assay and reversed phase HPLC. Atrazine (20 micrograms/l) stimulated fungal growth. Laccase-positive clone consumed up to 80% of atrazine within four weeks. However, no correlation of atrazine consumption and laccase activity in the culture medium was observed. Moreover, the laccase-negative clone was also capable of consuming at least 60-70% of atrazine within three weeks. Surprisingly, in the corresponding control set (cultivation of laccase-negative clone without atrazine) an unidentified metabolite having a retention time and UV-spectrum similar to those of atrazine was also found. It was concluded that the presence of laccase was not a crucial factor in atrazine consumption by this fungus.

[Enzymatic hydrolysis of willow treated with a steam burst without preliminary water extraction with a high concentration of substrate]. / Fermentativnyi gidroliz obrabotannoi parovym vzryvom drevesiny ivy bez predvaritel'noi vodnoi ékstraktsii pri vysokoi kontsentratsii substrata.

A laboratory reactor equipped with a screw press was used for hydrolysis of steam-SO2 exploded willow Salix caprea by a composition of Trichoderma reesei and Aspergillus foetidus enzyme preparations at high substrate concentrations. Optimal conditions providing the maximal volume of hydrolysis syrup with maximal sugar concentrations were determined. Two different hydrolysis procedures were developed in order to exclude initial washing of steam-pretreated plant raw material by large volumes of water, which is necessary to eliminate the inhibitory effect of explosion by-products on enzymatic hydrolysis. The first procedure included a one-hour-long enzymatic prehydrolysis of the substrate, then separation of sugar syrup containing 40-60 g/l of glucose, 20-25 g/l of xylose, and up to 10% of disaccharides, as well as up to 35% of the initial enzymatic activity, then addition of a diluted acetate buffer (pH 4.5), and subsequent hydrolysis of the substrate by the adsorbed enzymes leading to the final accumulation of up to 140 g/l glucose and up to 15 g/l xylose. In the second scenario, the exploded willow was initially adjusted by alkali to pH 4.5 and then hydrolyzed directly by added enzymes for 24 hours. This procedure resulted in a nearly total polysaccharide hydrolysis and accumulation of up to 170 g/l glucose and 20 g/l xylose. The reasons of inhibition of enzymatic hydrolysis are discussed.

[The Ecology Department of the Russian University of the Friendship of Peoples--a scientific, pedagogical and social concept]. / Ekologicheskii fakul'tet Rossiiskogo universiteta druzhby narodov--nauchno-pedagogicheskaia i sotsial'naia kontseptsiia.

The paper is about the foundation of the Environmental Department in the Russian University of Friendship of Peoples with a scientific-educational center of environmental biology and advanced technologies, the faculties of system and industrial environmental biology, human and radiation environmentology with the purpose to boost environmentalism and eco-culture.

[Characteristics of adenosine triphosphatase activity in carp erythrocytes treated with saponin]. / Osobennosti aktivnosti adenozintrifosfataz v éritrotsitakh karpa, obrabotannykh saponinom.

The activities of Ca-ATPase and Na,K-ATPase in saponin-treated erythrocytes of man, rat and carp were compared. It was shown that at free calcium concentrations lower than 1 microM the activity of Ca-ATPase in carp erythrocytes was by one order of magnitude lower than in rat erythrocytes and 3-4 times lower than in human red blood cells. At [Ca2+] = 0.4 microM the activities of Na,K-ATPase in all species under study were essentially the same. The increase in Ca2+ concentration up to 1 microM resulted in a 2-5-fold activation of Na,K-ATPase in rat and carp erythrocytes, respectively. In all cases studied a further elevation of free calcium concentration was accompanied by a decline of the Na,K-ATPase activity. It was shown that the Pi content in carp erythrocytes is 5-6 times as high as that in mammalian cells. This circumstance is a considerable obstacle to a detailed analysis of mechanisms of ATPase activity regulation in carp erythrocytes by methods used for determination of inorganic phosphate production.

[An immunochemical analysis of the induction of cytochrome P-450 isoforms in the liver of fresh-water fishes by 3-methylcholanthrene, beta-naphthoflavone and aroclor 1254]. / Immunokhimicheskii analiz induktsii izoform tsitokhrom P-450 v pecheni presnovodnykh ryb 3-metilkholantrenom, beta-naftoflavonom i arokhlorom 1254.

The cytochrome P-450 isoforms have been studied in liver microsomes of some fish species from Lake Baikal. Using the inhibitory analysis of microsomal monooxygenase activities carried out by the specific polyclonal antibodies it has been shown that 3-methylcholanthrene, beta-naphthoflavone and arochlor 1254 induce isoforms immunologically related to cytochrome P-488c but not to the rat cytochrome P-450b in fish liver microsomes. The immunologic identity in isoforms of fish and rat cytochromes induced by methylcholanthrene has not been revealed. A possibility to use the method of the inhibitory analysis of fish microsomal activities by specific antibodies to the rat cytochrome P-450 isoforms for biomonitoring and biotesting of polycyclic hydrocarbons and polychlorinated biphenyls in aquatic systems is discussed.

[Does alpha-tocopherol interact with the active center of cytochrome P-450 in liver microsomes?]. / Vzaimodeistvuet li al'fa-tokoferol s aktivnym tsentrom tsitokhroma P-450 v mikrosomakh pecheni?

The interaction of alpha-tocopherol (alpha-T) and its synthetic derivative 2,2,5,7,8-pentamethyl-6-hydroxy-chroman (PMC) with cytochrome P-450 system was studied in the rat liver microsomes. Spectral differentiations of type I, increase of NADPH oxidation rate and inhibition of 7-ethoxycoumarin deethylase in microsomes were observed only in the presence of PMC. The results obtained suggest that unlike alpha-T, PMC is effectively bound and metabolized by cytochrome P-450.

[Inhibition of the dealkylating activity of cytochrome P-450 isoforms in rat liver microsomes by the products of phospholipase A2-induced phospholipid hydrolysis]. / Ingibirovanie dealkiliruiushchei aktivnosti izoform tsitokhroma P-450 v mikrosomakh pecheni krysy produktami gidroliza fosfolipidov fosfolipazoi A2.

The effects of exogenous phospholipase A2, oleic acid and lysolecithines on oxidative NADPH-dependent O-dealkylation of 7-ethoxycumarin in liver microsomes of phenobarbital- and 3-methylcholanthrene-induced and non-induced rats were studied. Oleic acid up to the concentration of 100 micrograms/mg of protein did not inhibit this process. gamma-Myristoyl and gamma-palmitoyl lysolecithines decreased the reaction rate already at concentrations of 2-4 micrograms/mg of protein. Oleic acid was attached to cytochrome P-450 according to type I binding, whereas lysolecithines did not bind to the cytochrome. Thus, in the presence of phospholipase A2 in liver microsomes of non-induced rats, when the phospholipid hydrolysis products are accumulated at low concentrations, 7-ethoxycumarin deethylase is inhibited by lysophospholipids but not by free fatty acids. In 3-methylcholanthrene-induced microsomes the sensitivity of O-deethylation of 7-ethoxycumarin to the inhibiting effect of phospholipase A2 or lysolecithine is lower than that in non-induced or phenobarbital-induced microsomes.

[Effect of stress on the cardiomyocyte transmembrane potential of the working heart and its recovery after hypothermia]. / Vliianie stressa na transmembrannyi potentsial kardiomiotsitov rabotaiushchego serdtsa i ego vosstanovlenie posle gipotermii.

Emotional-painful stress in rats was shown to decrease insignificantly transmembrane cardiomyocyte potential (TCP) measured in isolated hearts. The recovery of TCP following its depression due to the preparation cooling was twice slower in stress-exposed than in control animals. This is in keeping with the data on stress-induced disturbances of Na, K-ATPase activity (an enzyme playing a leading role in TCP maintenance). It is suggested that the disturbance in cation pump function activity plays a certain role in the onset of arrhythmias and cardiac fibrillation during stress.

[Release of Ca2+ ions from the sarcoplasmic reticulum of skeletal muscle induced by heparin. Relation between the Ca2+ release caused by Ca2+ ions and caffeine]. / Osvobozhdenie ionov Ca2+ iz sarkoplazmaticheskogo retikuluma skeletnykh myshts pod deistviem geparina. Sviaz' s osvobozhdeniem Ca2+ pod deistviem ionov Ca2+ i kofeina.

Using a Ca2+-selective electrode and Quin 2 and chlortetracycline fluorescence, a Ca2+ release from terminal cysterns of skeletal muscle sarcoplasmic reticulum under effects of heparin, caffeine and Ca2+ has been studied. It was shown that Ca2+ release induced by heparin is insensitive to the blockers of Mg2+-dependent system of Ca2+-induced Ca2+ release, i.e., Mg2+, tetracaine and dimethylsulfoxide. Preliminary release of Ca2+ in the presence of caffeine, which activates Mg2+-dependent Ca2+ release, does not prevent the heparin-induced Ca2+ release. At the same time, after Ca2+ release caused by Ca2+ in a Mg2+-independent system, heparin cannot cause additional efflux of Ca2+. It has been shown that the heparin-induced release of Ca2+ diminishes with a decrease in a decrease in Ca2+ concentration. This effect is less pronounced in the presence of Na+ than with K+. The data obtained suggest that sarcoplasmic reticulum terminal cysterns contain two systems of Ca2+-induced release of Ca2+, i.e., a Mg2+-dependent, caffeine-sensitive and a Mg2+-independent heparin-sensitive ones. The mechanism of activation of both systems by caffeine and heparin consists, in all probability, in their increased affinity for Ca2+.

[Non-antioxidative mechanism of cytochrome P-450 stabilization by alpha-tocopherol: the effectiveness in avitaminosis E]. / Neantioksidantnyi mekhanizm stabilizatsii tsitokhroma P-450 alpha-tokoferolom: éffektivnost' pri avitaminoze E.

The efficiency of alpha-tocopherol as a 7-etoxycumarine deethylase protector in rat liver microsomes damaged by phospholipase A2 at various levels of vitamin E was studied. No selective damage of cytochrome P-450 isoforms possessing a catalytic activity towards 7-etoxycumarine under vitamin E deficiency was observed. Phospholipase A2 decreased the deethylase activity of cytochrome P-450, the efficiency of the damaging action being dependent on vitamin E content in the liver. Exogenous alpha-tocopherol exerts an antiphospholipase effect and protects 7-etoxycumarine deethylase; the protective action is inversely proportional to vitamin E level in the liver. Under normal conditions the damaging effect of phospholipase A2 on cytochrome P-450 is mainly provided for by lysophospholipids, while under vitamin E deficiency both lysophospholipids and free fatty acids exert a damaging action. A possible mechanism of the stabilizing effect of alpha-tocopherol may consist in the interaction of the chromanol nucleus in the vitamin E molecyule both with lysophospholipids and with free fatty acids.

[Activation of calcium transport in synaptosomes by phosphatidylinositol-specific phospholipase C]. / Aktivatsiia transporta kal'tsiia v sinaptosomakh fosfolipazoi C, spetsifichnoi k fosfatidilinozitam.

The isotope labeling method was used to study the influence of phospholipases C of different origin and specificity on Ca2+ accumulation in rat brain synaptosomes. It was found that phospholipases C specific to phosphatidylinositides (PI) stimulate Ca2+ transport into synaptosomes, while non-specific phospholipase C, which hydrolyzes different membrane lipid fractions, decreases the Ca2+ content in synaptosomes. It is supposed that the stimulating effect of PI-specific phospholipases C is determined by the activation of PI metabolism, which results in an increase in the content of some PI metabolism products serving as Ca2+ ionophores in synaptosomal membranes. The inhibition of Ca2+ uptake by synaptosomes treated with non-specific phospholipase C is thought to result from partial disruption of synaptosomal membranes.

[Ecological and toxicological control over the status of the environment by the methods of physicochemical biology]. / Ekologo-toksikologicheskii kontrol' za sostoianiem okruzhaiushchei sredy metodami fiziko-khimicheskoi biologii.

Xenobiotic metabolism in the fish liver has been investigated with a view of developing test-system for biomonitoring based on multienzyme membrane-bound complexes. Extraction methods of xenobiotics from harmful pollutants and some biological tissue have been described using various sorbents and solvents. The own and literary data on the study of mutagenic effect of this contaminants and carcinogens in the Ames test-system in the presence of postmitochondrial fraction S9 from fish liver with 3-methylcholanthrene induced by microsomal oxidation system have been demonstrated.

[Effect of caffeine on the Ca2+-transport function of sarcoplasmic reticulum vesicles in the rat myocardium]. / Vliianie kofeina na Ca2+-transportiruiushchuiu funktsiiu puzyr'kov sarkoplazmaticheskogo retikuluma iz miokarda krysy.

The effects of caffeine on active transport of Ca2 by heavy and light fractions of rat myocardial microsomes were investigated with the use of a Ca2+-selective electrode and nephelometry. It was found that under the effect of caffeine (5 mM) the rate of Ca2 transport in the presence of oxalate decreased by 30 to 40%. The caffeine-induced inhibition was prevented by ruthenium and tetracaine, thus suggesting the inhibitor specificity. Since caffeine is a specific blocker of Ca2 transport to the terminal cisterns of the skeletal muscle sarcoplasmic reticulum, it is assumed that the microsomal fraction of rat myocardium contains terminal cistern fragments.

[Prevention of stress-induced disorders of myocardial contractile function by using sparing adaptation to short-term stress effects]. / Preduprezhdenie stressornykh narushenii funktsii miokarda putem primeneniia shchadiashchei adaptatsii k korotkim stressornym vozdeistviiam.

Adaptation to repeated short-term stress is known to prevent to a considerable extent the depression of the myocardial contractile function which usually develops under long-term stress. But the adaptation itself has a "cost", i. e. it results in limited but significant disturbances of myocardial contractile function. The present review documents the method of adaptation involving few actions with prolonged intervals between them. It has been established that such an adaptation per se does not induce any disturbances of contractile function. At the same time it prevents completely the depression of contractile function caused by stress.

[Iron accumulation by saccharomycete yeasts growing on media with an elevated iron content]. / Akkumuliatsiia zheleza drozhzhami-sakharomitsetami pri roste na sredakh s povyshennym soderzhaniem zheleza.

In the absence of the artificial complexons of iron the intracellular iron content in yeast Saccharomyces cerevisiae are determined by the concentration of ions Fe(II) in medium. As iron is accumulated by yeast mainly in threevalency state the principal internal factor determining the intracellular iron content with existing concentration of Fe(II) in medium can be supposed to be redaction-oxidation state of yeast cell.