Vol 54, No 7 (2018)

A stepwise screening of bacterial xylanase producers isolated from forest soil in Moscow oblast has been performed, and the taxa of the microorganisms have been identified based on an analysis of the 16S RNA gene sequences. An approach to the selection of the most active producers is suggested, and this selection has been carried out, resulting in four producing strains. Interestingly, the species of two of the selected strains (Paenibacillus jamilae and P. brasilensis) are described as producers of xylanolytic enzymes for the first time, and the characteristics of those xylanases have not yet been studied. The new strains can serve as a source of genes for the construction of high-efficient xylanase producers.

The paper reports on the search for the superfamily of divergent species-specific PGU genes in ascomycetous yeasts in the GenBank (http://www.ncbi.nlm.nih.gov/genbank/) and the Sanger Institute (http://www.sanger.ac.uk) databases. It has been demonstrated that the species within the Eremothecium, Galactomyces, Geotrichum, Kluyveromyces, and Lachancea genera contain divergent pectinase genes. Within these genera, we observed the following levels of similarity between the nucleotide sequences of the PGU genes: 64.5–98.2% in Kluyveromyces, 72.7–81.3% in Galactomyces/Geotrichum, and 69–87.9% in Eremothecium. Polymeric PGU genes capable of interspecies transfer were found in Galactomyces citri-aurantii, Geotrichum klebahnii, and Galactomyces candidus. The importance of PGU genes for the diagnosis and selection of yeasts is discussed.

The recombinant B. anthracis strain 55ΔTPA-1Spo^– was used for the development and trial of a method for the simultaneous production of immunogenic anthrax antigens, a protective antigen, and the EA1 protein of the S layer, which are components of a prototype anthrax vaccine. The proposed method includes inoculum preparation, cultivation in liquid medium without antibiotics, sterilizing filtration, concentration, diafiltration, and chromatographic purification on various carriers. This method provides for a high yield of both target products. The purified antigens (alone or in combination with each other) were shown to have no toxic effect on organs and tissues of vaccinated laboratory animals in amounts that were several times higher than immunizing doses. The minor changes revealed by histological examination reflect the adaptation-compensatory reactions of the macroorganism and tend to normalize. The response of immune-competent organs corresponded to moderate development of immunogenesis. The addition of EA1 protein to the recombinant protective antigen resulted in an increase in the expression of the genes determining TLR of innate immunity. Immunization of laboratory animals with the combined preparation caused more pronounced immunobiological alterations in lymphoid organs than the use of only the protective antigen.