[Biologically active metabolites of the marine actinobacteria].

This review systematically data on the chemical structure and biological activity of metabolites of obligate and facultative marine actinobacteria, published from 2000 to 2007. We discuss some structural features of the five groups of metabolites related to macrolides and compounds containing lactone, quinone and diketopiperazine residues, cyclic peptides, alkaloids, and compounds of mixed biosynthesis. Survey shows a large chemical diversity of metabolites actinobacteria isolated from marine environment. It is shown that, along with metabolites, identical to previously isolated from terrestrial actinobacteria, marine actinobacteria synthesize unknown compounds not found in other natural sources, including micro organisms. Perhaps the biosynthesis of new chemotypes bioactive compounds in marine actinobacteria is one manifestation of chemical adaptation of microorganisms to environmental conditions at sea. Review stresses the importance of the chemical study of metabolites of marine actinobacteria. These studies are aimed at obtaining new data on marine microorganisms producers of biologically active compounds and chemical structure and biological activity of new low-molecular bioregulators of natural origin.

[DNA, RNA, and protein biosynthesis in cells of Yersinia pseudotuberculosis at various cultivation temperatures]. / Biosintez DNK, RNK i belka v kletkakh Yersinia pseudotuberculosis pri raznykh temperaturakh kul'tivirovaniia.

Y. pseudotuberculosis cells cultivated at temperatures of 37 degrees C and 8 degrees C were found to be capable of incorporating exogenic precursors into DNA, RNA and protein. The linear growth of thymidine incorporation occurred during 8 hours of cultivation at 37 degrees C, then the amount of the incorporated label decreased. At 8 degrees C the level of thymidine incorporation into DNA gradually increased for 80 hours and longer, but not reaching the level of incorporation observed at 37 degrees C. The incorporation of uridine into RNA of Y. pseudotuberculosis cells reached its maximum after 4 hours of cultivation at 37 degrees C, at a lower temperature of cultivation the incorporation of uridine into bacterial cells was almost linear, though slower, and lasted for 20 hours. The content of radioactive alanine in Y. pseudotuberculosis protein increased during 16 hours of cultivation at a high temperature, while at 8 degrees C the growth of the incorporation level lasted for at least 40 hours. For all precursors under study the incorporation rate into the cell biopolymers at the initial stages of cultivation was higher at 37 degrees C, than at a lower temperature.