Physiological features of achromogenic species of genus pseudomonas in dynamic conditions of thermal cultivation

The dominant group of bacteria in microbial flora of Karelian water is Pseudomonas genus. This biocoenosis phenomenon is observed in Karelian water basins due to high adaptive ability of the microorganisms. The most important physical factor affecting adaptive characteristics of the studied microorganisms is external temperature. Therefore, the aim of this work is to reveal and study the effect of thermal actions on growth parameters and development of Pseudomonas alcaligenes and Pseudomonas cichoril. 25 achromogenic strains of Pseudomonas alcaligenes and Pseudomonas cichoril allocated from Karelian water reservoirs and autoflora of fish were researched. Microorganisms were cultivated in beef-extract broth (BCH) at temperatures ranging from 5 to 35 °C for 24-120 hours. Spectrophotometric analysis identified bacteria’s’ growth rate, time required to reach the maximum density, and generation rate. The research showed that the highest growth rate in Pseudomonas alcaligenes and Pseudomonas cichoril is observed when cultivatin temperature reaches 15 °C. The shortest time to reach the maximum density of Pseudomonas alcaligenes is achieved at the temperature of -15 °C, and Pseudomonas cichoril -20 °C.