[Growth of phototrophic bacterium Rhodobacter sphaeroides and formation of carotenoids on mineral water "Dzhermuk"]. / Rost fototrofnoi bacterii Rhodobacter sphaeroides i obrazovanie eiu karotinoidov na mineral'noi vode "Dzhermuk".

A possibility to use thermal carbon sulphate-hydrocarbonate mineral waters "Dzhermuk" as the basis of nutrient medium for growing has been established. No distinct correlation was observed between biomass accumulation and carotenoids formation: maximum yields of the biomass is registered under microaetrophilic growth conditions, while that of carotenoids--under anaerobic conditions. Maximum synthesis of carotenoids is observed at illumination of 1000-1500 lx, more intensive illumination (3000 lx) results in the decrease of their synthesis. Spheroiden, which makes up about 40-45% of the total amount of carotenoids, is predominant. The biomass drying and storage period (2 yr.) affect inconsiderably the quantitative composition of pigments.

[Consumption of organic carbon sources and biosynthesis of lactic acid by the photosynthetic bacterium Rhodobacter sp. D-4]. / Usvoenie organicheskikh istochnikov ugleroda i biosintez molochnoi kisloty fotosinteziruiushchei bakteriei Rhodobacter sp., sht. D-4.

Nonsulfur photosynthetic purple bacteria isolated from the Dzhermuk mineral springs (Armenia) were grown on sugar-containing media and found to be capable of synthesizing L(+)-lactic acid. Various organic compounds were tested as possible sole sources of carbon and an electron donors required to support bacterial growth and biosynthesis of lactic acid under various growth conditions.

[Comparative characteristics of the ability to coagulate milk in different representatives of the order Actinomycetales]. / Sravitel'naia kharakteristika sposobnosti svertyvat' moloko u razlichnykh predstavitelei poriadka Actinomycetales

The ability to clot milk was studied among 482 cultures of Actinomycetales. The highest activity was manifested by thermophilic actinomycetes, the next come globisporous, white, and gray groups of the genus Actinomyces. Cultures belonging to the genera Mycobacterium and Mycococcus did not clot milk. The ability to clot milk can be used as an additional taxonomic index while studying ray fungi.