Diversity of bacteria of the genus Bacillus on board of international space station.

From swabs of surfaces of equipment and air samples of the Russian segment of the International Space Station, nine strains of spore-forming bacteria of the genus Bacillus belonging to the species B. pumilus, B. licheniformis, B. subtilis, B. megaterium, and B. amyloliquefaciens were isolated. The last species of bacilli on the equipment of RS ISS was detected for the first time. For these species of bacilli, there are known strains that can be opportunistic to humans, and their metabolites can cause biodegradation of equipment and materials. B. pumilus found on ISS belongs to the group of bacteria that exhibits a particularly high resistance to adverse environmental conditions, such as dehydration, ultraviolet and gamma radiation, and chemical disinfection.

[Phenotypic properties of Sulfobacillus thermotolerans: comparative aspects].

The phenotypic characteristics of the species Sulfobacillus thermotolerans Kr1(T), as dependent on the cultivation conditions, are described in detail. High growth rates (0.22-0.30 h(-1)) and high oxidative activity were recorded under optimum mixotrophic conditions at 40 degrees C on medium with inorganic (Fe(II), S(0), or pyrite-arsenopyrite concentrate) and organic (glucose and/or yeast extract) substrates. In cells grown under optimum conditions on medium with iron, hemes a, b, and, most probably, c were present, indicating the presence of the corresponding cytochromes. Peculiar extended structures in the form of cylindrical cords, never observed previously, were revealed; a mucous matrix, likely of polysaccharide nature, occurred around the cells. In the cells of sulfobacilli grown litho-, organo-, and mixotrophically at 40 degrees C, the enzymes of the three main pathways of carbon utilization and some enzymes of the TCA cycle were revealed. The enzyme activity was maximum under mixotrophic growth conditions. The growth rate in the regions of limiting temperatures (55 degrees C and 12-14 degrees C) decreased two- and tenfold, respectively; no activity of 6-phosphogluconate dehydrogenase, one of the key enzymes of the oxidative pentose phosphate pathway, could be revealed; and a decrease in the activity of almost all enzymes of glucose metabolism and of the TCA cycle was observed. The rate of 14CO2 fixation by cells under auto-, mixo-, and heterotrophic conditions constituted 31.8, 23.3, and 10.3 nmol/(h mg protein), respectively. The activities of RuBP carboxylase (it peaked during lithotrophic growth) and of carboxylases of heterotrophic carbon dioxide fixation were recorded. The physiological and biochemical peculiarities of the thermotolerant sulfobacillus are compared versus moderately thermophilic sulfobacilli.

[The dependence of intracellular ATP level on the nutrition mode of the acidophilic bacteria Sulfobacillus thermotolerans and Alicyclobacillus tolerans].

The dynamics of the ATP pool in the aerobic spore-forming acidothermophilic mixotrophic bacteria Sulfobacillus thermotolerans Kr1T and Alicyclobacillus tolerans K1T were studied in the course of their chemolithoheterotrophic, chemoorganoheterotrophic, and chemolithoautotrophic growth. It was established that, during mixotrophic growth, the maximum ATP concentrations in the cells of S. thermotolerans Kr1 and A. tolerans K1 were 3.8 and 0.6 nmol/mg protein, respectively. The ATP concentrations in sulfobacilli and alicyclobacilli during organotrophic growth were 2.2 and 3.1 nmol/mg protein, respectively. In the cells of the obligately heterotrophic bacterium Alicyclobacillus cycloheptanicus 4006T, the maximum ATP concentration was several times higher and reached 12.3 nmol/mg protein. During lithotrophic growth, the maximum values of the ATP concentration in the cells of S. thermotolerans Kr1 and A. tolerans K1 were 0.3 and <0.1 nmol/mg protein, respectively; in the cells of the autotrophic bacterium Acidithiobacillus ferrooxidans TFBk, the ATP content was about 60-300 times higher (17.0 nmol/mg protein). It is concluded that low ATP content is among the possible causes of growth cessation of S. thermotolerans Kr1 and A. tolerans K1 under auto- and heterotrophic conditions after several culture transfers.

[Effect of cultivation conditions on the growth and activities of sulfur metabolism enzymes and carboxylases of Sulfobacillus thermosulfidooxidans subsp. asporogenes strain 41]. / Vliianie uslovii kul'tivirovaniia na rost, aktivnost' fermentov metabolizma sery i karboksilaz u Sulfobacillus thermosulfidooxidans subsp. asporogenes, shtamm 41.

The moderately thermophilic acidophilic bacterium Sulfobacillus thermosulfidooxidans subsp. asporogenes strain 41 is capable of utilizing sulfides of gold-arsenic concentrate and elemental sulfur as a source of energy. The growth in the presence of S0 under auto- or mixotrophic conditions was less stable compared with the media containing iron monoxide. The enzymes involved in oxidation of sulfur inorganic compounds--thiosulfate-oxidizing enzyme, tetrathionate hydrolase, rhodonase, adenylyl sulfate reductase, sulfite oxidase, and sulfur oxygenase--were discovered in the cells of Sulfobacillus grown in the mineral medium containing 0.02% yeast extract and either sulfur or iron monoxide and thiosulfate. Cell-free extracts of the cultures grown in the medium with sulfur under auto- or mixotrophic conditions displayed activity of the key enzyme of the Calvin cycle--ribulose bisphosphate carboxylase--and several other enzymes involved in heterotrophic fixation of carbonic acid. Activities of carboxylases depended on the composition of cultivation media.

[Sulfur metabolism enzymes in thermoacidophilus bacteria Sulfobacillus sibiricus]. / Fermenty metabolizm sery u termoatsidofil'noi bakterii Sulfobacillus sibiricus.

Sulfur oxygenase, sulfite oxidase, adenylyl sulfate reductase, rhodanase, sulfur:Fe(III) oxidoreductase, and sulfite:Fe(III) oxidoreductase were found in cells of aerobic thermoacidophilic bacteria Sulfobacillus sibiricus strains N1 and SSO. Enzyme activity was revealed in cells grown on the medium with elemental sulfur or in the presence of various sulfide elements and concentrates of sulfide ores. The activity of sulfur-metabolizing enzymes depended little on the degree of aeration during bacterial growth.

[Activity of the enzymes of carbon metabolism in Sulfobacillus sibiricus under various conditions of cultivation]. / Aktivnost' fermentov uglerodnogo obmena u Sulfobacillus sibiricus v razlichnykh usloviiakh kul'tivirovaniia.

The thermoacidophilic iron-oxidizing chemolithotroph Sulfobacillus sibiricus N1T is characterized by steady growth and amplified cell yield when grown in vigorously aerated medium containing Fe2+, glucose, and yeast extract as energy sources. In this case, carbon dioxide, glucose, and yeast extract are used as carbon sources. Glucose is assimilated through the fructose-bisphosphate pathway and the pentose-phosphate pathway. Glyoxylate bypass does not function in S. sibiricus, and the tricarboxylic acid cycle is disrupted at the level of 2-oxoglutarate dehydrogenase. The presence of ribulose-bisphosphate carboxylase indicates that carbon dioxide fixation proceeds through the Calvin cycle. The activity of ribulose-bisphosphate carboxylase is highest in autotrophically grown cells. The cells also contain pyruvate carboxylase, phosphoenolpyruvate carboxylase, phosphoenolpyruvate carboxykinase, and phosphoenolpyruvate carboxytransphosphorylase.

[The enzyme of carbon metabolism in the thermotolerant sulfobacillus strain K1]. / Fermenty metabolizma ugleroda u termotolerantnoi sul'fobatsilly, shtamm K1.

To determine enzymatic activities in the thermotolerant strain K1 (formerly "Sulfobacillus thermosulfidooxidans subsp. thermotolerans"), it was grown in a mineral medium with (1) thiosulfate and Fe2+ or pyrite (autotrophic conditions), (2) Fe2+, thiosulfate, and yeast extract or glucose (mixotrophic conditions), and (3) yeast extract (heterotrophic conditions). Cells grown mixo-, hetero-, and autotrophically were found to contain enzymes of the tricarboxylic acid (TCA) cycle, as well as malate synthase, an enzyme of the glyoxylate cycle. Cells grown organotrophically in a medium with yeast extract exhibited the activity of the key enzymes of the Embden-Meyerhof-Parnas and Entner-Doudoroff pathways. An increased content of carbon dioxide (up to 5 vol%) in the auto- and mixotrophic media enhanced the activity of the enzymes involved in the terminal reactions of the TCA cycle and the enzymes of the pentose phosphate pathway. Carbon dioxide was fixed in the Calvin cycle. The highest activity of ribulose bisphosphate carboxylase was detected in cells grown autotrophically at the atmospheric content of CO2 in the air used for aeration of the growth medium. The activities of pyruvate carboxylase, phosphoenolpyruvate carboxylase, phosphoenolpyruvate carboxykinase, and phosphoenolpyruvate carboxytransphosphorylase decreased with the increasing content of CO2 in the medium.

[Effects of exogenous factors on the activity of enzymes involved in carbon metabolism in thermoacidophilic bacteria of the genus Sulfobacillus]. / Vliianie ékzogennykh faktorov na aktivnost' fermentov metabolizma ugleroda u termoatsidofil'nykh bakterii roda Sulfobacillus.

Aerobic thermoacidophilic chemolithotrophic bacteria Sulfobacillus thermosulfidooxidans 1269T and Sulfobacillus thermosulfidooxidans subsp. asporogenes 41 were shown to be resistant to stress factors, including high concentrations of Zn2+ (0.8 M) and H+ (pH 1.2) that exceeded the optimum values. The growth and biomass gain rates decreased, but bacteria retained their functions. The activity of nearly all enzymes involved in carbon metabolism decreased. Glucose was primarily metabolized via the Entner--Doudoroff pathway. The activity tricarboxylic acid cycle enzymes decreased compared to that in cells grown under normal conditions. After saturation of the growth medium with 5 vol % CO2, sulfobacteria utilized glucose by the Embden-Meyerhof and pentose phosphate pathways under mixotrophic conditions.

[Growth and carbohydrate metabolism of sulfobacilli]. / Rost i uglevodnyi metabolizm sul'fobatsill.

The moderately thermophilic acidophilic bacteria Sulfobacillus thermosulfidooxidans, strain 1269, S. thermosulfidooxidans subsp. "asporogenes," strain 41, and the thermotolerant strain S. thermosulfidooxidans subsp. "thermotolerans" K1 prefer mixotrophic growth conditions (the concomitant presence of ferrous iron, thiosulfate, and organic compounds in the medium). In heterotrophic and autotrophic growth conditions, these sulfobacilli can grow over only a few culture transfers. In cell-free extracts of these sulfobacilli, key enzymes of the Embden-Meyerhof-Parnas, pentose-phosphate, and Entner-Doudoroff pathways were found. The role of a particular pathway depended on the cultivation conditions. All of the enzymes assayed were most active under mixotrophic conditions in the presence of Fe2+ and glucose, suggesting the operation of all of the three major pathways of carbohydrate metabolism under these conditions. However, the operation of the Entner-Doudoroff pathway in strain 41 was restricted under mixotrophic conditions. After the first culture transfer from mixotrophic to heterotrophic conditions, the utilization of glucose occurred only via the Embden-Meyerhof-Parnas and Entner-Doudoroff pathways. After the first culture transfer from mixotrophic to autotrophic conditions, the activity of carbohydrate metabolism enzymes decreased in all of the strains studied; in strain K1, only the glycolytic pathway remained operative. The high activity of fructose-bisphosphate aldolase, remaining in strain 41 cells under these conditions, suggests the involvement of this enzyme in the reactions of the Calvin cycle or of gluconeogenesis.

[The activity of the carbon metabolism enzymes in Chromatium minutissimum after long-term preservation]. / Aktivnost' fermentov uglerodnogo metabolizma u Chromatium minutissimum posle dlitel'nogo khraneniia.

The activity of the enzymes of the tricarboxylic acid cycle and glyoxylate shunt, as well as of some enzymes involved in carbohydrate metabolism, were determined in the purple sulfur bacterium Chromatium minutissimum, either maintained by subculturing in liquid medium or stored in the lyophilized state for 36 years. In cultures stored in the lyophilized state, the activities of the key enzymes of the tricarboxylic acid cycle, glyoxylate shunt, and Embden-Meyerhof-Parnas pathway were higher, whereas the activities of glucose-6-phosphate dehydrogenase, pyruvate kinase, and ribulose bisphosphate carboxylase were somewhat lower than in cultures maintained by regular transfers.

[Carbon metabolism in Sulfobacillus thermosulfidooxidans subsp. asporogenes, strain 41]. / Metabolizm ugleroda u Sulfobacillus thermosulfidooxidans subsp. Asporogenes, shtamm 41.

The activities of carbon metabolism enzymes were determined in cellular extracts of the moderately thermophilic, chemolithotrophic, acidophilic bacterium Sulfobacillus thermosulfidooxidans subsp. asporogenes, strain 41, grown either at an atmospheric content of CO2 in the gas phase (autotrophically, heterotrophically, or mixotrophically) or autotrophically at a CO2 content increased to 5-10%. Regardless of the growth conditions, all TCA cycle enzymes (except for 2-oxoglutarate dehydrogenase), one glyoxylate cycle enzyme (malate synthase), and some carboxylases (ribulose bisphosphate carboxylase, pyruvate carboxylase, and phosphoenolpyruvate carboxylase) were detected in the cellular extracts of strain 41. During autotrophic cultivation of strains 41 and 1269, the increase in the CO2 content of the supplied air to 5-10% resulted in the activation of growth and iron oxidation, a 20-30% increase in the cellular content of protein, enhanced activity of the key TCA enzymes (citrate synthase and aconitase), and, in strain 41, a decrease in the activity of carboxylases.

[The effect of heat shock on the formation and composition of actinomycins]. / Vliianie teplovogo shoka na obrazovanie i sostav aktinomitsinov.

The effect of various conditions of heat shock on production of actinomycins by Streptomyces chrysomallus 2 and their composition was studied. The actinomycin biosynthesis was shown to be the function of the growing mycelium and changed in accordance with changes in the volume of the mycelium and its morphological features after heat shock at various suboptimal temperatures. The temperature shock had a specific action on the antibiotic synthesis: the index of the actinomycin maximum quantity increased after the heat shock at 35 and 38 degrees C and lowered more sharply than that of the biomass volume after the heat shock at the temperatures of 40, 42, 45 and 50 degrees C for 1 hour. After the shock at 38 degrees C the component composition of the actinomycin complex did not significantly change while with addition of exogenic amino acids such as L-valine, L-leucine and L-isoleucine the shock effect on the component composition of the actinomycin complex was marked.

[The effect of heat shock on the growth and mycelial morphology of Streptomyces chrysomallus]. / Vliianie teplovogo shoka na rost i morfologiiu mitseliia Streptomyces chrysomallus.

The effect of various conditions of heat shock (1 hour at 35, 38, 40, 42, 45 and 50 degrees C) on the growth and morphological features of Streptomyces chrysomallus, an organism producing actinomycin, was studied. A definite regularity in the mycelium morphological changes at high temperatures was observed. After the shock at 35 and 38 degrees C the biomass volume and morphological features of the streptomycete did not markedly differ from those in the control. The shock at 40 degrees C induced the growth inhibition with decreasing the biomass volume by 50 per cent and appearance of submerged spores. When the shock conditions were more rigid (42, 45 and 50 degrees C) the mycelium growth lacked. It is of interest that the temperature of 42 degrees C induced abundant formation of the spores. With further increasing of the temperature to 45 and 50 degrees C the spore formation was not so abundant. The changes in the growth and development of the streptomycete are discussed in relation to the molecular mechanism of the cell protection from temperature shock.

[Effect of heat shock on biosynthesis of antibiotics by three strains of Streptomyces]. / Vliianie teplovogo shoka na biosintez antibiotikov tremia shtammami Streptomyces.

Effects of heat shock on the biosynthesis of antibiotics, actinomycin C (in cultures of Streptomyces sp. 26-115 and S. chrysomallus 23209) and antibiotics of the nonactin group (in the culture of S. werraensis 1365) were studied. After heat shock, the formation of antibiotics of the nonactin group and actinomycin C were shown to increase by 30% and 27%, respectively, in comparison to control values. Thus, heat shock stimulates the biosynthesis of antibiotics in all three strains of streptomyces studied.

[Propionate metabolism of Ectothiorhodospira shaposhnikovii during growth in the dark]. / Metabolizm propionata u Ectothiorhodospira shaposhnikovii pri roste v temnote.

Assimilation of propionate by Ectothiorhodospira shaposhnikovii growing under the aerobic conditions in the dark, like in the light involves carboxylation of propionyl-CoA with the participation of biotin-dependent carboxylase. The succinate being formed is transformed in the reactions of the citric acid cycle and the glyoxylate shunt. This is corroborated by the determination of the enzyme activity manifested by cell extracts, by the composition and kinetics of labeled products, as well as by the action of the inhibitors of the citric acid cycle (fluoroacetate, malonate) and avidin on the assimilation of 14C-propionate and 14CO2 by the cells.

[Acetate metabolism in Ectothiorhodospira shaposhnikovii growing in the dark]. / Metabolizm atsetata u Ectothiorhodospira shaposhnikovii pri roste v temnote.

When the cells of Ectothiorhodospira shaposhnikovii assimilated 1- and 2-14C-acetate for a short period of time in the dark under aerobic conditions, the greatest amount of 14C was found after 5 sec in malate, succinate and aspartate. The content of 14C in these compounds decreased in due time, but increased in phosphoglyceric acid and in phosphoric esters of sugars, citrate, alanine and glutamate. The composition and kinetics of labeled products formed during the assimilation of 14C-acetate by the cells in the dark did not depend on the presence of thiosulfate. The cells of Ectothiorhodospira shaposhnikovii grown in the dark, like those grown in the light, contained all enzymes of the citric acid cycle with an exception of alpha-ketoglutarate dehydrogenase. Moreover, they produced enzymes of the glyoxylate shunt, malate synthase and isocitrate lyase, whose activity was higher than that in cells grown in the light. The activity of ribulosediphosphate carboxylase in cells grown in the dark was much lower than in cells grown under phototrophic conditions in a medium with acetate. Cells grown either in the dark or in the light displayed also the activity of phosphopyruvate carboxylases (E.C. 4.1.1.3.1 and 4.1.1.38) and pyruvate carboxylase (E.C. 6.4.1.1). The results suggest that the utilization of acetate in the dark under aerobic conditions by the cells of E. shaposhnikovii is related to the operation of the glyoxylate cycle and the citric acid cycle.

[Growth of Ectothiorhodospira mobilis in the dark]. / Rost v temnote Ectothiorehodospira mobilis.

The purple photosynthetic bacterium Ectothiorhodospira mobilis, like E. shaposhnikovii, can grow in the dark in the presence of oxygen on organic media, in particular, containing acetate or malate. The source of sulfur may be sulfate or thiosulfate. The two bacteria grown in the light and in the dark display the activity of all the enzymes of the citric acid cycle, with the exception of alpha-ketoglutarate dehydrogenase, and possess the enzymes of the glyoxylate shunt (isocitrate lyase and malate synthase). Irrespective of the conditions of the cultural growth, active fixation of carbon dioxide by the cells of E. mobilis was found only in the light.

[Relationship between growth conditions and assimilation of acetate and bicarbonate by Ectothiorhodospira shaposhnikovii]. / Usvoenie atsetata i bikarbonata Ectothiorhodospira shaposhnikovii v zavisimosti ot uslovii rosta.

The cells of Ectothiorhodospira shaposhnikovii grown under the anaerobic conditions in the light and in the dark under the aerobic conditions in a medium with acetate can fix considerable amounts of CO2 only in the presence of light. Incorporation of 14C from the labeled acetate into the cells in the dark does not depend on the presence of bicarbonate and inorganic electron donors through assimilation of 14C-acetate in the light increases significantly in the presence of bicarbonate and sulfide or thiosulfate. Fluoroacetate (5.0 . 10(-3) M) completely inhibits assimilation of 14C-acetate by the cells and formation of 14CO2 from it in the dark under the aerobic conditions, regardless of the growth conditions and the presence of inorganic electron donors. In the light, fluoroacetate produces a similar effect on 14C-acetate assimilation by the cells only in the absence of bicarbonate and inorganic electron donors. Therefore, carbon metabolism in Ectothiorhodospira shaposhnikovii differs in the light and in the dark.