## 1 Introduction  
The modern biotechnology of microalgae is developing along with the concept of integrated production systems, the interconnection of which ensures the efficient use of resources and the reduction of anthropogenic pressure on the environment [1]. The results of many studies prove that various microalgae successfully purify both wastewater and flue gases while simultaneously producing valuable metabolic products [2, 3]. Although the environmental aspects of microalgae cultivation deservedly occupy a place among promising \"green\" technologies [4], the scalability of algal biomass production models is limited by technical and economic factors. The most important tasks in developing cost-effective cultivation models are the improvement of the designs of cultivation systems and the optimization of growth parameters in accordance with the physiological characteristics of different strains [5]. The main obstacles to growing microalgae are associated with a low biomass density, which increases cultivation costs, increases the risk of contamination, and leads to low yields of the targeted metabolic products. For microalgae as photosynthetic microorganisms, the intensity and duration of light, as well as the CO\({}_{2}\) concentration, are the main environmental parameters that significantly affect the cultures' growth [6]. It has been noted that the optimization of both parameters should be considered in combination [7, 8]. Microalgae species adapt to different light conditions; however, to ensure optimal growth, it is important to establish several basic light parameters, including intensity, frequency, and emitted spectrum [9]. The intensity and duration of light influence the rate of photosynthesis, as well as the specific growth rate of an algal culture [10], the synthesis of commercially important products [11], and the removal of nutrients from the medium [12]. At the same time, providing the algal cells with light of sufficient intensity depends on the surface-to-volume ratio of a photobioreactor and the efficiency of the mixing devices [13]. Equipping reactors with artificial light sources increases production costs, but at the same time stabilizes biomass production, making it independent of external factors [14]. Under natural conditions, the duration of light is determined by seasonal and daily fluctuations, while application of artificial light sources makes it possible to control the light and dark cycles or to cultivate microalgae under continuous light [12]. In a liquid medium, gaseous inorganic carbon passes into a dissolved form, available to algal cells in the form of CO\({}_{2}\)(aq) or HCO\({}_{3}\)\({}^{-}\)[15]. The degree of dissolution, and hence the efficiency of CO\({}_{2}\) fixation by algal cells, depends on the size of the gas bubbles and the residence time in the liquid. The degree of CO\({}_{2}\) biofxation is determined by the difference between the concentration of gas entering and exiting a photobioreactor, by the amount of carbon in the biomass, and by other methods using sophisticated analytical equipment [16; 17]. Parameters such as light intensity, temperature, and pH have a significant impact on photosynthetic carbon fixation degree [18]. Studies on the ability to utilize CO\({}_{2}\) and the effect of the CO\({}_{2}\) concentration on biomass production have been studied for several microalgae of the genera _Chlorella_[19; 20], _Scenedesmus_[20; 21; 22], _Chlorococcus_[23], and other microalgae, which are characterized by rapid growth and high tolerance of stress factors. However, most studies are conducted to find evidence for the use of microalgae from different geographic regions for CO\({}_{2}\) sequestration, and the optimal light requirements of the microalgae are often not considered. Species with high CO\({}_{2}\) tolerance have great potential in carbon dioxide sequestration technologies [24; 25].