[Physiological, biochemical, and cytological characteristics of a halotolerant and alkalitolerant methanotroph grown on methanol]. / Fiziologo-biokhimicheskie i tsitologicheskie osobennosti galoalkalotolerantnogo matanotrofa pri roste na metanole.

The halotolerant alkaliphilic methanotroph Methylomicrobium buryatense 5B is capable of growth at high methanol concentrations (up to 1.75 M). At optimal values of pH and salinity (pH 9.5 and 0.75% NaCl), the maximum growth rate on 0.25 M methanol (0.2 h-1) was twice as high as on methane (0.1 h-1). The maximum growth rate increased with increasing medium salinity and was lower at neutral than at alkaline pH. The growth of the bacterium on methanol was accompanied by a reduction in the degree of development of intracytoplasmic membranes, the appearance of glycogen granules in cells, and the accumulation of formaldehyde, formate, and an extracellular glycoprotein at concentrations of 1.2 mM, 8 mM, and 2.63 g/l, respectively. The glycoprotein was found to contain 23% protein and 77% carbohydrates, the latter being dominated by glucose, mannose, and aminosugars. The major amino acids were glutamate, aspartate, glycine, valine, and isoleucine. The glycoprotein content rose to 5 g/l when the concentration of potassium nitrate in the medium was augmented tenfold. The activities of sucrose-6-phosphate synthase, glycogen synthase, and NADH dehydrogenase in methanol-grown cells were higher than in methane-grown cells. The data obtained suggest that the high methanol tolerance of M. buryatense 5B is due to the utilization of formaldehyde for the synthesis of sucrose, glycogen, and the glycoprotein and to the oxidation of excess reducing equivalents through the respiratory chain.

[Synthesis of osmoprotectors by halophilic and alkalophilic methanotrophs]. / Sintez osmoprotektorov galofil'nymi i aklalofil'nymi metanotrofami.

The 1H-NMR analysis of methanol extracts of halophilic and halotolerant alkaliphilic methanotrophs isolated from the soda lakes of Southern Transbaikal and Tuva showed that bacterial cells grown at an optimum salinity accumulated mainly sucrose and 5-oxo-1-proline, whereas cells adapted to 0.5-1.0 M NaCl additionally synthesized ectoine. A more detailed study showed that nitrogen deficiency in the growth medium of Methylobacter alcaliphilus 20Z decreased the synthesis of nitrogen-containing osmoprotectants, ectoine and 5-oxo-1-proline. M. alcaliphilus 20Z cells exhibited activities of UDP-glucose pyrophosphorylase and sucrose-phosphate synthase involved in sucrose synthesis. Glutamine synthetase in vitro did not require NH4+ ions, which implies that this enzyme is involved in 5-oxo-1-proline synthesis. Cells grown at high salinity exhibited elevated levels of aspartate kinase, aspartate-semialdehyde dehydrogenase, and ectoine synthase. This suggests that ectoine is synthesized via aspartate and aspartate-semialdehyde, i.e., via the route earlier established for extremely halophilic bacteria.

[Utilization of detoxification products of yperite-lewisite mixtures]. / Utilizatsiia produktov detoksikatsii ipritno-liuizitnoi smesi.

An approach to developing an ecologically safe technology for disposal of yperite-lewisite mixtures has been developed. The technology includes three sequential stages: (1) detoxification by alkaline hydrolysis (resulting in the loss of toxic properties); (2) electrochemical treatment of detoxification products (electrocoagulation, to eliminate arsenic salts, and electrochemical oxidation, to convert all organic components into bioutilizable matter); and (3) degradation of the compounds obtained at the two preceding stages by a bred microbial association.

[Scientific principles of complex ecologically-safe technology of mustard gas destruction]. / Nauchnye osnovy kompleksnoi ékologicheski bezopasnoi tekhnologii unichtozheniia iprita.

The principles of complex, ecologically-safe technology for the destruction of battle gas mustard were worked out. This technology was based on the reaction alkaline detoxication of mustard; the major component of reaction mixture obtained after detoxication was thiodiglycol. Thorough thiodiglycol mineralization was achieved by electrochemical treatment. Electrolysis products were biologically utilized in biosorber.

[Effect of heavy water on the growth, glucose assimilation and stability of Escherichia coli to freezing-thawing]. / Vliianie tiazheloi vody na rost, assimiliatsiiu gliukozy i ustoichivost' Escherichia coli k zamorazhivaniiu-ottaivaniiu.

Growth and resistance to freezing--thawing of Escherichia coli B-1640 were investigated during cultivation in synthetic media prepared with H2O and D2O. It is found that during cultivation in D2O the maximum specific growth rate decreases and the duration of the exponential growth phase increases. During the growth in D2O the glucose consumption rate drops in the exponential growth phase, the lactate content in the culture liquid is lower by two orders than that in H2O; the resistance to freezing--thawing is lower than that in H2O. After leaving the exponential phase the culture in D2O restores specific growth rate, glucose consumption rate and resistance to freezing--thawing up to the values obtained during the growth in H2O. The translation ability of ribosomes isolated from cells grown in D2O and H2O is the same. We conclude that the culture adapts to D2O during the exponential growth phase. It is suggested that during the adaptation the second carbon source is used which compensates the consequences of the disturbances of glucose metabolism and transport caused by deuteration of the cell content in the adaptation to D2O.

[Intracellular and extracellular alkaloids of Penicillium roqueforti]. / Vnutri-i Vnekletochnye alkaloidy Penicillium roqueforti.

The alkaloid composition of mycelium and culture liquid filtrate of the fungus Penicillium roqueforti IBPM-F-141 was studied. The new metabolite--3,12-dihydroroquefortine, a derivative of roquefortine, the main component of the alkaloid fraction of this culture, has been isolated for the first time. The structure of 3,12-dihydroroquefortine was determined by chemical and physico-chemical methods. In addition to roquefortine and 3,12-dihydroroquefortine, representatives of a new alkaloid group, the clavine alkaloids, e. g. isofumigaclavine A, isofumigaclavine B and festuclavine, were also isolated and identified. The data on the content of these compounds in mycelium and culture medium are presented.