[New antibiotics produced by Bacillus subtilis strains].

Two Bacillus subtilis strains isolated from the fruiting body of a basidiomycete fungus Pholiota squarrosa exhibited a broad range of antibacterial activity, including those against methicillin-resistant Staphylococcus aureus INA 00761 (MRSA) and Leuconostoc mes6nteroides VKPM B-4177 resistant to glycopep-> tide antibiotics, as well as antifungal activity. The strains were identified as belonging to the "B. subtilis" com- plex based on their morphological and physiological characteristics, as well as by sequencing of the 16S rRNA gene fragments. Both strains (INA 01085 and INA 01086) produced insignificant amounts of polyene antibiotics (hexaen and pentaen, respectively). Strain INA 01086 produced also a cyclic polypeptide antibiotic containing Asp, Gly, Leu, Pro, Tyr, Thr, Trp, and Phe, while the antibiotic of strain INA 01085 contained, apart from these, two unidentified nonproteinaceous amino acids. Both polypeptide antibiotics were new compounds efficient against gram-positive bacteria and able to override the natural bacterial antibiotic resistance.

[Extracellular glycosyl hydrolase activity of the clostridia producing acetone, butanol, and ethanol].

Production of acetone, butanol, ethanol, acetic acid, and butyric acid by three strains of anaerobic bacteria, which we identified as Clostridium acetobutylicum, was studied. The yield of acetone and alcohols in 6% flour medium amounted to 12.7-15 g/l with butanol constituting 51.0-55.6%. Activities of these strains towards xylan, beta-glucan, carboxymethylcellulose, and crystalline and amorphous celluloses were studied. C. acertobutylicum 6, C. acetoburylicum 7, and C. acertobutylicum VKPM B-4786 produced larger amounts of acetone and alcohols and displayed higher cellulase and hemicellulase activities than the type strain C. acetobutylicum ATCC 824. It was demonstrated that starch in the medium could be partially substituted with plant biomass.

[Pigmented basidiomycete yeasts are a promising source of carotenoids and ubiquinone Q10].

Strains of basidiomycete yeasts isolated from different sources were studied in order to determine the content of carotenoid pigments and ubiquinone Q10 for subsequent selection work to obtain producers of these substances. High specific productivity of carotenoids (600-700 mg/g) was revealed in the representatives of the following species: Cystofilobasidium capitatum. Rhodosporidium diobovatum, R. sphaerocarpum. Rhodotorula glutinis, Rh. minuta, and Sporobolomyces roseus. The ratio of the major pigments (torulene, torularhodine, and beta-carotene) in the representatives of different species was studied. Certain specific features of pigment formation in relation to the taxonomic position of the yeasts were determined. Eurybiont species with substantial ecological lability are the most active producers of carotenoids and ubiquinone Q10 among the epiphytes. It is the first time a comparative analysis of the coenzyme Q10 content in different taxa has been performed using several strains of the same species. The maximal coenzyme Q10 production (1.84 mg/g of dry biomass) was found in the yeast species R. sphaerocarpum.

[Features of lipoxygenase from cells of Mortierella species mushrooms]. / Osobennosti lipoksigenzay iz kletok gribov roda Mortierella.

The specific activity of lipoxygenase from several strains of the zygomycete Mortierella varied from 1.02 to 2.02 microMol diene per min per mg protein). The enzyme equally used linoleic or arachidonic acid as a substrate. An increase in lipoxygenase activity was observed after adding corn oil to the culture medium. Tests with inhibitors having different chemical structures revealed that the lipoxygenase activity from Mortierella cells was inhibited only by esculetin, ethanol and nordihydroguaiaretic acid (NDGA). NDGA inhibited the enzyme in vitro (IC50 = 142 microM), but its addition in the exponential phase of growth activated the enzyme.

[Cosmid libraries containing DNA from human chromosome 13]. / Issledovanie kosmidnykh bibliotek, soderzhashchikh DNK khromosomy 13 cheloveka.

We characterized two cosmid libraries constructed from flow-sorted chromosome 13 at the Imperial Cancer Research Fund (ICRF), UK (13,000 clones) and Los Alamos National Laboratory (LANL), USA (17,000 clones). After storage for two years, clones showed high viability (95%) and structural stability. EcoR I and Hind III restriction patterns were studied in more than 500 ICRF and 200 LANL cosmids. The average size of inserts was shown to be 35-37 kb in both the libraries. Most cosmids (83% and 93% of ICRF and LANL libraries, respectively) exceed the lower size limit of DNA fragments that can be packaged and represent a good source for physical mapping of chromosome 13. Total length of inserts is four and five genome equivalents in the ICRF and LANL libraries, respectively. ICRF cosmids showed hybridization to 22 of 24 unique probes tested, which corresponds to a 90% probability of having any DNA fragment represented in the library. More than 1 Mb of chromosome 13 is overlapped by 90 cosmids of 22 groups revealed. A chromosomal region of more than 150 kb, containing the ATP1AL1 gene for alpha-1 peptide of Na+, K(+)-ATPase, is covered by 12 cosmids forming a contig. The results of restriction and hybridization analyses are stored in a CLONE database. These data and all the cosmids described are publicly available.

[Cloning and complementation analysis of the Escherichia coli gpr locus, influencing DNA replication of certain lamdoid phages]. / Klonirovanie i komplemntatsionnyi analiz lokusa gpr Escherichia coli, bliiaiushchego na replikatsiiu DNK nekotorykh liambdoidnykh fagov.

Escherichia coli DNA fragments which suppressed gpr27 and gpr2 mutations in the earlier proposed gprA and gprB genes, respectively, were cloned within phage vectors. Mutations gpr2 and gpr27 restrict DNA replication of some lambdoid phages and are located in the region of dnaK, J genes. DNA-DNA hybridization showed that the cloned fragments correspond to the region where gpr mutations were genetically mapped and, in some cases, do not include dnaK, J genes. These results provide the evidence that gprA and gprB genes may be physically separated from dnaK, J genes.

[Genetic control of resistance of Escherichia coli K12 to phage C1]. / Geneticheskii kontrol' rezistentnosti Escherichia coli K12 k fagu C1.

The bacteriophage C1 isolated in production cycle lysis belongs to the most common group of bacteriophages wide spread in nature and having the long noncontractile motile tail. Bacterial cells sensitivity to bacteriophage C1 is determined by functioning of the three different loci mapped in different regions of Escherichia coli map at 89, 75 and 61 min. The possibility of existence of a complex receptor for bacteriophage C1 is discussed.

[Pleiotropic effect of the rpoC mutation in Escherichia coli K-12 reducing the frequency of lysogenization by phage lambda]. / Pleiotropnyi éffekt rpoC-mutatsii Escherichia coli K-12, snizhaiushchei chastotu lizogenizatsii kletok fagom lambda.

We described earlier the isolation of lfl25 mutation reducing the frequency of lysogenization of mutant cells by phage lambda (LycA phenotype). The mutation is mapped at present in the rpoC gene coding for the beta' subunit of bacterial RNA polymerase and named rpoC90. It is dominant and causes decrease in pools of some branched amino acids, pyrimidines and thiamine (vitamin B1) in mutant cells. Combination of rpoC90 mutation with some Rif-r mutations strengthens both the LycA phenotype and deficiency in metabolites mentioned above. Such combination was shown to also cause a defect in antitermination (or increases the efficiency of termination) of transcription on the DNA of lambdoid phage phi 434. This defect may indicate the possible mechanism of changes in the regulation of different bacterial operons induced by rpoC90 mutation.

[Escherichia coli phage receptors. Minor porins and proteins participating in the specific transport as phage receptors]. / Fagovye retseptory Escherichia coli. Neosnovnye poriny i belki, uchastvuiushchie v spetsificheskom transporte kak fagovye retseptory.

Except for the main porin proteins OmpC and OmpF there exist the membrane proteins participating in the transport of specific substrates: phosphates, nucleosides, iron, vitamin B12, maltose and maltodextrins, that also play the role of phage receptors. Some phages use as receptors the porins determined by the genes of lambdoid prophages. LamB protein that serves receptor for phage lambda exposes the amino acids sequence on the outer surface of membranes that participates in phage adsorption. The sequence is similar to tetrapeptide of fibronectin responsible for binding with the surface of cellular receptor in eucaryotes.

[Phage receptors of Escherichia coli. Basic components of the outer membrane of E. coli as phage receptors]. / Fagovye retseptory Escherichia coli. Osnovnye komponenty naruzhnoi membrany E. coli kak fagovye retseptory.

Major outer membrane components which determine the structure and the barrier function of membrane Gram-negative bacteria are receptors for many bacteriophages. LPS--the major component of the outer membrane of Enterobacteria can be used by some phages with wide host range specificity. The other component of the outer membrane frequently include phage receptor component is OmpA protein. OmpA protein different areas can be used as receptors for different phages T--even group. A large group of phage receptors compose porin proteins, which are discovered in 32 species of bacteria. The synthesis of major porin proteins, which a receptor for several phages, are regulated by sufficiently complex system of some genes. These genes are sensitive to the changes of environment.

[Use of sensitivity to antibiotics produced by representatives of the genera Williopsis and Zygowilliopsis in the identification of yeasts]. / Ispol'zovanie chuvstvitel'nosti k antibiotikam, obrazuemym predstaviteliami rodov Williopsis i Zygowilliopsis, v identifikatsii drozhzhei.

Yeast strains belonging to the genera Candida and Hansenula were shown to differ in their susceptibility to the action of protein antibiotics produced by the yeasts Williopsis and Zygowilliopsis. This finding can be used as an additional criterion for yeast identification.

[Isolation and genetic analysis of bacterial mutations gpr blocking the replication of various lambda phages]. / Vydelenie i geneticheskoe izuchenie bakterial'nykh mutatsii gpr, blokiruiushchikh replikatsiiu nekotorykh liambdoidnykh fagov.

Bacterial mutations affecting phi 80 DNA replication have been isolated and designated gpr2, 27. The main difference between gpr2, 27 and groP, grp mutations described earlier is that mutations gpr2, 27 are not essential for lambda replication. The mutations have been mapped between thr and leu loci in the vicinity of mutations groPC756 (dnaK gene) and groPC259 (dnaJ gene), their order being: thr-gpr2-groPC756-groPC259-gpr27. Complementation analysis using transducing phages suggested that mutations gpr2, 27 are localized in genes unknown earlier, outside dnaK and dnaJ genes.

[Isolation of Escherichia coli K-12 mutants that affect the development of phage phi m173 (imm phi 80)]. / Vydelenie mutantov Escherichia coli K-12, vliiaiushchikh na razvitie faga fi m173 (imm fi 80).

Escherichia coli mutants which block the development of a number of lambdoid phages, particularly, phi m173 and phi 80 were selected. These mutants have different phenotypes, being resistant to different groups of lambdoid phages. There are also differences between new mutants and gro mutants of E. coli studied earlier. The results obtained support the suggestion that no replication of different lambdoid phages takes place in these mutants.

[Direct method of selecting LycA mutants of Escherichia coli K-12]. / Priamoi metod otbora LycA-mutantov Escherichia coli K-12.

Lambdoid phage form clear plaques and show reduced ability to establish immunity in LycA mutants of Escherichia coli. This study was undertaken to isolate new LycA mutants. For this purpose, a selective method for isolation of LycA mutants was developed. Two groups of LycA mutants have been isolated and analyzed. It was shown that lysogenization with lambdoid phages may depend on the different bacterial genes.

[Regulation of int gene expression in phage phi 81]. / Reguliatsiia vyrazheniia gena int faga phi 81.

Phi 81 phage, like lambda, was shown to possess, in addition to cI (repressor) gene, two other genes--cII and cIII, essential for immunity establishment. Expression of phi 81 int gene is positively controlled by cII and cIII gene products. The products of cII and cIII genes of phi 81 phage do not complement analogous lambda genes functions.

[Hybrid plasmid pSD1 containing the immunity region of bacteriophage lambda]. / Gibridnaia plazmida pSD1, soderzhashchaia oblast' immuniteta bakteriofaga lambda.

Hybrid plasmid pSD1 carrying the immunity region of the coliphage lambda and bio operon have been obtained by means of studying the efficiency of transcription DNA fragments in the plasmid RSF2124. The molecular weight of this plasmid is 17.2 Md. The growth inhibition of phage lambdavir has been observed in cells carrying the new hybrid plasma. The properties of the plasmid pSD1 and probable reasons of the growth inhibition of phage lambdavir are discussed. The hybrid plasmid pSD2 carrying genes R, A and J of phage lambda has been constructed on the basis of the plasmid RSF2124. There are cohesive ends in this plasmid which make possible its packing in the phage lambda head. Hybrid plasmid pSD3 carrying genes P and Q of phage lambda has also been constructed.