Mitochondrial DNA haplogrouping of the brown bear,Ursus arctos (Carnivora: Ursidae) in Asia,based on a newly developed APLP analysis

Sequence analyses of the complete brown bear, Ursus arctos, mitochondrial DNA (mtDNA) genome have detected scattered single nucleotide polymorphisms (SNPs) that define distinct mtDNA haplogroups in phylogeographical studies. The degraded DNA in historical samples, such as stuffed or excavated specimens, however, is often not suitable for sequence analyses. To address this problem, we developed an amplified product length polymorphism (APLP) analysis for mtDNA‐haplogrouping U. arctos specimens by detecting haplogroup‐specific SNPs. We verified the validity and utility of this method by analysing up to 170‐year‐old skin samples from U. arctos specimens collected widely across continental Eurasia. We detected some of the same haplogroups as those occurring in eastern Hokkaido (Japan) and eastern Alaska in continental Eurasia (the Altai and the Caucasus). Our results show that U. arctos in eastern Hokkaido and eastern Alaska descended from a common ancestor in continental Eurasia, and suggest that U. arctos occupied several refugia in southern Asia during the Last Glacial Maximum. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 111 , 627–635.     

Comparison of changes in succinate dehydrogenase activity in blood lymphocytes and modification of radiosensitivity by exogenous hypoxia

Radioprotective efficiency of gas hypoxic mixtures (GHM) containing 5-12% of oxygen and the rate of the reaction of succinate dehydrogenase (VSDG) activity in peripheral blood lymphocytes upon breathing GHM were comparatively studied in rats and dogs. VSDG was 4393.5 (%O2)-2.58 and 130.76 (%O2)-1.42 in dogs and rats respectively. Taking into account that DMF in rats is a function of oxygen concentration in the mixture one can obtain a formula for determining a dose modifying factor (DMF) as a function of the rate of SDG activity reaction.     

Radiosensitivity during the irradiation of animals in an altered gaseous environment. A comparative study on mice and rats of the radiation-protective effect of oxygen-deficient gas mixtures

The radioprotective effect of gas hypoxic mixtures containing 5, 7, 8, 10 and 15% of oxygen on mice and rats was comparatively studied. The dependence of DMF upon oxygen concentration in the mixture was approximated by a hyperbolic function similar to the dependence of the radiomodifying effect of circulatory hypoxia caused by radioprotective agents of the indolylalkylamine series.     

Continuous stereospecific Δ-3-keto-steroid reduction by PAAH bead-entrapped Clostridium paraputrificum cells

The development of a continuous anaerobic process for stereospecific Δ⁴-3-keto-steroid reduction by immobilized Clostridium paraputrificum cells cells is described. Following a study on conditions for cell growth and sporulation, spores of C. paraputrificum were aseptically immobilized in PAAH beads. Conditions for cell growth and induction in the immobilized state were determined, as well as the medium composition required to maintain a stabilized immobilized cell population. The effect of the concentration of ethylene glycol added as selected cosolvent on reaction kinetics, substrate solubility, specific activity, and cell growth, was investigated. A 10% (v/v) cosolvent input provided maximal activity along with enhanced solubility of the steroidal substrate. It was shown that cell growth was enhanced in the presence of the added cosolvent in addition to its effect on substrate solubility and enzymic activity. The immobilized cells readily performed Δ⁴, as well as 3-keto steroid reduction of several steroids, including ADD, AD, 16-dehydroprogesterone, progesterone, and hydrocortisone. It was shown that repeated batch-wise reduction cycle—in the presence of the cosolvent—resulted in rapid loss of activity, while the continuous uninterrupted process permitted the attaining of full bioconversion level, maintained stable for at least the period of 5 days of continuous operation tested.     

Fixation and stabilization of Escherichia coli cells displaying genetically engineered cell surface proteins

A large biotechnological potential is inherent in the display of proteins (e.g., enzymes, single-chain antibodies, on the surface of bacterial cells) (Georgiou et al., 1993). Applications such as immobilized whole-cell biocatalysts or cellular adsorbents require cell fixation to prevent disintegration, stabilization of the anchored protein from leakage, denaturation or proteolysis, and total loss of cell viability, preventing medium and potential product contamination with cells. In this article we describe the adaptation of a simple two-stage chemical crosslinking procedure based on "bi-layer encagement" (Tor et al., 1989) for stabilizing Escherichia coli cells expressing an Lpp-OmpA (46-159)-beta-lactamase fusion that displays beta-lactamase on the cell surface. Bilayer crosslinking and coating the bacteria with a polymeric matrix is accomplished by treating the cells first with either glutaraldehyde or polyglutaraldehyde, followed by secondary crosslinking with polyacrylamide hydrazide. These treatments resulted in a 5- to 25-fold reduction of the thermal inactivation rate constant at 55 degrees C of surface anchored beta-lactamase and completely prevented the deterioration of the cells for at least a week of storage at 4 degrees C. The stabilization procedure developed paves the way to scalable biotechnological applications of E. coli displaying surface anchored proteins as whole-cell biocatalysts and adsorbents. (c) 1996 John Wiley & Sons, Inc.     

Intracellular proteinase of Bacillus subtilis.

An intracellular serine proteinase was isolated from Bacillus subtilis, strain A-50. The molecular weight of the enzyme is 30000 +/- 1000, its amino acid composition is enriched in glutamic acid residues, the isoelectric point is 4.3, the N-terminal sequence Glu-Leu-Pro-Glu-Gly-Ile-Gln-Val-Ile-Lys-Ala-Pro-Glu-Leu-Xxx-Ala-Gln-Gly-Phe-Lys Gly-Ser-Asx-Ile-Lys-Ile-Ala-Val-Leu-Asx. The enzyme is structuraly homologous with secretory subtilisins.     

Nucleotide sequence of the Yersinia pestis gene encoding F1 antigen and the primary structure of the protein. Putative T and B cell epitopes.

The plasmid-located gene caf1 encoding the capsular antigen fraction 1 (F1) of Yersinia pestis was cloned and sequenced. The gene codes for a 170 amino acid peptide with a deduced Mr of 17.6 kDa. The signal peptide sequence was highly homologous to the E. coli consensus signal sequence. The F1 was assumed to have beta-sheet structure for the most part. The region located between amino acids 100 and 150 was suggested to contain putative antigenic determinants and to stimulate T cells.     

Biodegradation of pollutants in the aerial discharges from antibiotic biosynthesis

Possible biodegradation of air pollution from antibiotic biosynthesis in the form of water condensates was studied in a 1000 ml laboratory bioreactor with using active sludge. The biodegradation of such a pollution was shown possible. The process kinetics was described by the Michaelis-Menten equation. The values of the equation constants were calculated.     

Mutation glass-like of Drosophila melanogaster Suppresses Expression of mini-white Transgenes Depending on Their Genomic Environment

Pleiotropic recessive mutation glass-like (gl-l) found in region 8C10–8E of the X chromosome was shown to cause glass-like eyes having no boundaries between facets and a nonuniform pigment distribution determined by the endogenous white. The gl-lmutation completely inhibited expression of the mini-white transgene contained in several constructs, but the effect depended on the site of construct insertion in the genome. The mutation had no effect on the expression of the white transgene having the enhancer and flanked by insulators. The gl-l mutation did not affect the extent of mosaic eye pigmentation when a construct with mini-white was inserted in the telomeric or pericentric region. However, in most cases it completely inhibited the mosaic mini-white expression when cloned heterochromatic repeats were adjacent to the reporter gene in a construct. The gl-l gene was assumed to play a role in the formation of the chromatin structure, because the effect of its mutation on expression of the white transgene depended on the transgene insertion site, the presence of insulators or an enhancer in the vicinity of the transgene, and on the adjacent heterochromatic repeats.