[Biotechnological Potential of the Bacillus subtilis 20 Strain].

Bacillus subtilis bacteria play an important role in veterinary medicine, medicine, and biotechnology, and the permanently growing demand for biotechnological products fuels the improvement of the properties of biotechnological strains. B. subtilis strains with improved characteristics maybe obtained by rational design and the directed evolution technologies, or be found among newly described strains. In the course of the long-term microbiome composition studies in the Russian segment of the International Space Station, the B. subtilis 20 strain was isolated, this strain shows the capacity for rapid growth and considerable biomass accumulation, as well as increased resistance to acidification of the environment in comparison to the "terrestrial" B. subtilis 168 strain. What is more, B. subtilis 20 is hyperresistant to the DNA and protein damaging factors that are linked to the overexpression of the genes controlling DNA repair, hydrogen sulfide production, and reactive oxygen species neutralization. The described properties of B. subtilis 20 are indicative of its considerable potential as a promising producer of biologically active compounds.

[Candida glabrata Rpn4-like Protein Complements the RPN4 Deletion in Saccharomyces cerevisiae].

Expression of Saccharomyces cerevisiae proteasomal genes is regulated in a coordinated manner by a system that includes the ScRpn4 transcription factor and its binding site known as PACE. Earlier we showed that, Rpn4-like proteins from the biotechnologically important yeast species Komagataella pfaffii (Pichia pastoris), Yarrowia lipolytica, and Debaryomyces hansenii are capable of complementing the RPN4 deletion in S. cerevisiae in spite of their low structural similarity to ScRpn4. The opportunistic yeast pathogen Candida glabrata has a gene coding for a Rpn4-like protein, which has not been characterized experimentally yet. The С. glabrata ortholog ScRpn4 was expressed heterologously and found to restore the stress resistance and expression of proteasomal genes in a mutant S. cerevisiae strain with a RPN4 deletion. This complementation required the unique N-terminal region of CgRpn4. The results indicate that CgRpn4 acts as a transcriptional activator of proteasomal genes. The S. cerevisiae model can be used for further structural and functional analyses of CgRpn4.