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.

[Monitoring of microbial degraders in manned space stations].

Samples of microorganisms from the surface of constructions of Mir Space Station (Mir SS) were taken and examined after 13 years of operation. The following microorganisms were isolated and identified: 12 fungal species belonging to the genera Penicillium, Aspergillus, Cladosporium, and Aureobasidium; 3 yeast species belonging to the genera Debaryomyces, Candida, and Rhodotorula; and 4 bacterial species belonging to the genera Bacillus, Myxococcus, and Rhodococcus. The predominant species in all samples was Penicillium chrisogenum. It was shown that the fungi isolated could damage polymers and induce corrosion of aluminum-magnesium alloys. We commenced a study of microbial degraders on constructions of the Russian section of the International Space Station (RS ISS). Twenty-six species of fungi, bacteria, yeasts, and actinomycetes, known as active biodegraders, were identified in three sample sets taken at intervals. We founded a collection of microorganisms surviving throughout space flights. This collection can be used to test spacecraft production materials, in order to determine their resistance to biodegradation.

[Effect of cloned DNA fragment from Streptomyces chrysomallus No.2 on metabolism in Streptomyces strains]. / Vliianie klonirovannogo fragmenta DNK Streptomyces chrysomallus #2 na metabolizm riada shtammov streptomitsetov.

The effects on cloned DNA fragment carrying an actinomycin resistance determinant on physiological processes in streptomyces strains with various potencies in producing this antibiotic, their inactive mutants, and model strain of Streptomyces lividans 66 were studied. This fragment was shown to modulate bacterial resistance to actinomycin and biosynthesis of antibiotics.

[Biosynthes of polyketide antibiotics by various actinomycin producing Streptomyces species]. / Biosintez antibiotikov poliketidnoi prirody u razlichnykh vidov streptomitsetov--produtsentov aktinomitsinov.

A collection of actinomycin-producing Streptomyces strains, their variants with different levels of antibiotic biosynthesis, and recombinant strains were screened in order to select new strains that produce polyketide antibiotics. Screening with the use of the cloned act gene encoding a component of actinorhodin polyketide synthase (PKS) multienzyme complex from Streptomyces coelicolor revealed that many strains tested can synthesize polyketide antibiotics along with actinomycins. A relationship between biosynthetic pathways of actinomycins and polyketides is discussed.

[Activities of certain enzymes in blood of the Pleurodeles waltl newt]. / Aktivnosti nekotorykh fermentov v krovi tritona Pleurodeles waltli.

The goal of the study was to evaluate the physiological and biochemical status of Pleurodeles waltli (urodele amphibian) by monitoring enzymatic activity in blood plasma and/or lood cell components. The following enzymes were chosen: glutamate dehydrogenase (GDH), aspartate and alanine aminotransferases (GOT and GPT), superoxide dismutase, catalase, isocitrate dehydrogenase, and glucose-6-phosphate dehydrogenase. With the exception of GDH, GOT and GPT, enzymatic activity was noticeably higher in blood of females as compared to males. Reflecting destructive processes in organism, under normal conditions levels of GOT and GPT activity in plasma are very much equal in females and males. Differences in activities of the other enzymes were proportional to levels of steroid hormones in blood plasma of animals.

[An antibiotic complex produced by Streptomyces werraensis 1365T strain]. / Antibioticheskii kompleks, obrazuemyi shtammom Streptomyces werraensis 1365 T.

An antibiotic complex comprising four components (A, B, C, and X) was extracted from a native solution and mycelium of Streptomyces werraensis 1365T. The components were purified by column and thin-layer (TLC) chromatographic procedures to study their physicochemical and biological properties. The results were used to identify the substances isolated. The preliminary data allowed us to identify the components X, A, and B as the previously described compounds undecylprodigiosin, anisomycin, and copiamycin, respectively, whereas component C is a natural compound, which probably has never been described.

[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.

[Development of a system for cloning a DNA fragment, containing the determinant of resistance to actinomycin for Streptomyces chrysomallus No.2--a producer of actinomycin C]. / Razrabotka sistemy klonirovaniia fragmenta DNK, soderzhashchego determinat ustoichivosti k aktinomitsinu Streptomyces chrysomallus No. 2--produtsenta aktinomitsina C.

To study the modes of actinomycin biosynthesis and the mechanism responsible for resistance to the antibiotic producing S. chrysomallus No. 2, the authors undertook an examination and studies into the cloning system for gene(s) of resistance to actinomycin from a S. chrysomallus No. 2 actinomycin C producer and the cloning of a S. chrysomallus No. DNA fragment to the actinomycin-sensitive Streptomyces Sp. 26-115 H-I on the vector plasmid pIJ702. The cloning gave rise to actinomycin-resistant strains. The character of actinomycin resistance is inheritable in a steady fashion.

[Isolation of a plasmid from actinomycin C-producing Streptomyces chrysomallus and its characteristics]. / Vydelenie plazmidy iz Streptomyces chrysomallus--produtsenta aktinomitsina C--i ee kharakteristika.

Until now the identification of plasmids in streptomyces, the producers of actinomycins, has not been reported, although there exist the genetic data on the possible plasmid participation in biosynthesis of these antibiotics. In this paper the data are presented on plasmid identification in two variants of Streptomyces chrysomallus. Plasmids are shown to be identical in both variants differing in productiveness. The restriction map is constructed for this 7000 b. p. plasmid. Plasmid participation in actinomycin biosynthesis and its possible use for molecular cloning in streptomyces are discussed.

[Comparative biochemical study of 2 natural inactive variants of the actinomycin C producer Actinomyces sp. 26-115 with varying sensitivity to actinomycin]. / Sravnitel'noe biokhimicheskoe izuchenie dvukh estestvennykh neaktivnykh variantov produtsenta aktinomitsina C Actinomyces sp. 26-115 s razlichnoi chuvstvitel'nost'iu k aktinomitsinu.

Two natural variants of the actinomycin C-producing organism Actinomyces sp-26-115, i.e. H1 and H2 differ in their sensitivity to exogenic actinomycin, colony morphology, growth dynamics on the synthetic medium and stability to ultrasound and lysozyme. Both variants synthesize no actinomycin. Variant H1 is sensitive to exogenic actinomycin, while variant H2 is resistant to it. Variants H1 and H2 have some similarity in the composition of membrane proteins. Still, they differ in the protein molecular masses, which are equal to 600000--500000, 220000, 130000. The active variant A and nonactive variant H2 have the most similar compositions of membrane proteins. These variants are also close in their growth dynamics, colony morphology, sensitivity to ultrasound and lysozyme. The membranes of all the variants studied contain phosphatidyl ethanol amide as the main phospholipid component. Insignificant differences are observed only with respect to the minor components. The content of teichoic acids in the cell walls of variant H2 is very high, slightly changes during the developmental stage and insignificantly increases on addition of actinomycin to the medium. The cell wall of variant H1 contains less amounts of teichoic acids. During the developmental stage they are liberated from the wall at a higher rate than peptidoglycan. The sensitivity to actinomycin does not increase with an increase in the culture age. It is probable that teichoic acid of the cell wall is one of the factors providing resistance to actinomycin in variant H2. It may be considered as a barrier preventing transport of exogenic actinomycin into the cell.

[Membrane proteins of active and inactive variants of Actinomyces sp. 26-115, a producer of actinomycin C]. / Membrannye belki aktivnogo i neaktivnogo variantov Actinomyces sp. 26-115, produtsenta aktinomitsina C.

Some properties of the membrane proteins of Actinomyces sp. 26-115, i. e. its active variant and a variant not producing actinomycin C were studied comparatively. The membrane proteins of both variants of all ages tested represented a heterogenous fraction including about 30 protein components with a molecular mass of 17000 to 500000. There were differences in the protein component composition of the active and inactive variants. The membrane proteins of the active variant contained much more disulfide bonds than those of the inactive variant. It was shown in the model experiments on the protein binding of the phospholipid-lecithin membranes that the membrane proteins of the active variant bound higher amounts of lecithin during the whole developmental cycle than those of the inactive variant. It is suggested that the membrane proteins of the active variant had conformation differences as compared to those of the inactive variant.

[Characteristics of the active and inactive variants of Actinomyces sp. 26-115, a producer of actinomycin C]. / Nekotorye osobennosti aktivnogo i neaktivnogo variantov Actinomyces sp. 26-115, produtsenta aktinomitsina C.

Two natural variants, i.e. No. 1 and No. 2, not producing actinomycin were isolated from cultures of the actinomycin C-producing organism Actinomyces sp. 26-115. Variant No. 1 differed from the active variant by the growth dynamics and colony morphology. Variant No. 2 was close to the active variant by the growth dynamics. It was shown with electron microscopy that the cells of variant No. 1 differed from those of the active variant in the number and form of the mycelial septa, more even and compact structure of the cell walls and higher sensitivity to actinomycin. Still, they were more stable to the effect of lysozyme and ultrasound. The cell walls of the inactive variant No. 1 gradually lost teichoic acid during development, while the loss of peptidoglycan was observed only on transfer to the stationary phase. The cell walls of the active variant lost teichoic acid and peptidoglycan at the same time on transfer to the stationary phase. Peptidoglycans of both variants contained diaminopimelic acid (the configuration of which was not determined) and glycine (1:1) as differentiating amino acids. The two adjacent tetrapeptides were joined with one glycine radical. The peptidoglycan peptide chains of both variants contained muramic, glutamic and diaminopimelic acids and alanine (1:1:1:2). The peptidoglycans of the inactive variant No. 1 contained in addition valine and isoleucine. However, it is hardly probable that they are contained by the peptidoglycan peptide chains.

[Isolation of the membranes of Actinomyces sp. 26-115, a producer of actinomycin C]. / Poluchenie membran Actinomyces sp. 26-115, produtsenta.

A summation fraction of the membranes of Actinomyces sp. 26-115 was obtained as a result of lysis of its protoplasts in a hypotonic medium. The qualitative content of protein, lipids, phospholipids, nucleic acids, glucosamine and muramic acid was determined in the membranes at various stages of the organism development. Phosphatidylcholine is the main component of phospholipids in this organism. Intracellular actinomycin was found inside the protoplasts. Electrophoregrams of the microprotoplasts and membranes are presented. Actinomycin was also detected in the membranes. Still, it is not clear whether it is a component of the membrane or it is adsorbed on the membrane during the process of its isolation. The final conclusion on the relationship between the membrane and localization of actinomycin in the cell requires further investigation.

[Aspects of the biosynthesis of actinomycin C]. / Nekotorye aspekty biosinteza aktinomitsina C.

The protoplasts of Actinomyces sp. 26--115 producing actinomycin C were obtained by the action of lysozyme on the mycelial paste of a 48-hour microbial culture. The protoplast capacity for synthesizing actinomycin was decreased as compared to that of the intact mycelium. The transport of L-isoleucine, a precursor of actinomycin C biosynthesis in the protoplasts also decreased but this could not be the only cause of the decrease in the actinomycin biosynthesis capacity. The biosynthesis of actinomycin C by the protoplasts of Actinomycin sp. 26--115 did not require galactose and was not inhibited by glucose and exogenic actinomycin.

[Source of valine for protein V biosynthesis in a producer of actinomycin C]. / Istochnik valina dlia biosinteza belka v produtsente aktinomitsina C.

The specific activity of 14C-valine in valyl-tRNA formed during incubation of the actinomycin C-producing organism with 14C-valine was constant and lower than that of the whole cell pool. The constancy of the valyl-tRNA was indicative of the presence of a separate compartment for the valine pool used for protein biosynthesis. A lower specific activity of valine in valyl-tRNA as compared to that of the whole cell pool may be indicative of a low rate of valine metabolism in such separate compartment with exogenic 14-valine or a higher concentration of free valine in it as compared to the specific activity of this amino acid at average per cell.

[Heterogeneity of L-valine pool in Actinomyces sp. 26-115 producing actinomycin C]. / Geterogennost' pula L-valina Actinomyces sp. 28-115 produtsenta aktinomitsina C.

Free intracellular valine in Actinomyces sp. 26-115 producing actinomycin C its functionally heterogenous. There are at least 2 pools of free valine. One of them supplies valine for protein biosynthesis and the second for the antibiotic biosynthesis. The volume of the pools is estimated. Inadequate reaction of the pools to similar effects is indicative of differences in their properties. The pool participating in protein biosynthesis strives for preservation of its volume. The pool participating in the antibiotic biosynthesis is capable of enlarging its volume to various levels depending on the change in the volume of the common intracellular pool.

[L-valine transport by the actinomycete Actinomyces species 26-115, the producer of actinomycin C]. / Transport L-valina aktinomitsetom Actinomyces species 26-115--produtsentom aktinomitsina C

Transport of L-valine by Actinomyces species 26-115, an organism producing actinomycin C depended on L-valine concentration in the medium and temperature and required a source of intrinsic energy. Km for L-valine transport was 3.5.10(-6)--6.0.10(-6) M. It somewhat differed from experiment to experiment. The above system transported also other neutral amino acids. L-isoleucine was a competing inhibitor of L-valine transport. The transport of L-valine was stereospecific. The activity of the transport system was regulated by the intracellular content of L-valine. Probably because of this the amino acid transport depended on the culture age, so far as the level of free valine in the mycelium at various stages of development was different.