ASSESSMENT OF TOLERANCE OF MICROALGAE TO DIFFERENT TEMPERATURE REGIMES

Abstract

Today there is a serious environmental problem - global climate change, and one of the main reasons for this change is the release of so-called greenhouse gases, and primarily raw carbon dioxide. One strategy to reduce the concentration of carbon dioxide in the atmosphere is to capture carbon dioxide from industrial emissions, since this is where the gas is found in high concentrations. In addition to physical and chemical methods, carbon dioxide capture is possible with the help of biological methods, for example, using microalgae. However, the optimal growth temperatures for microalgae are in the range of 20-30 degrees Celsius, and the emission temperature is much higher. In general, heat-resistant species can be distinguished, for example, from hot springs. But, as a rule, such species require specific growing conditions, which on an industrial scale will lead to an increase in the cost of equipment. The purpose of this work was to carry out adaptation to semi-high temperatures of microalgae species selected from local conditions. We conducted an experiment in which we compared the growth of three types of green microalgae isolates at room temperature and elevated temperature. The isolates were used in their initial state and after adaptation at gradually elevated temperatures. It was demonstrated that temperature adoption led to higher yield of the isolates when they were cultivated at 36 -C. Thus, for strain 2 the Dopt of the previously adapted variant 2e was 1.9-fold higher as compared with that of the initial variant 2i. For the other two strains such a difference was less, but still significant. The results obtained demonstrate the potential of the green algal species to be adopted to elevated temperature which is important for their future use in the biotechnologies of carbon capturing from the industrial emissions.