The influence of the nutrient medium on the morphological features and cell viability of the microalgae Chlorella vulgaris Beijer

This paper discusses morphological features and the nature of the viability of the cell groups of the microalgae Chlorella vulgaris Beijer., growing in an artificial nutrient medium. It has been found that in the morphological aspect, the microalgae have a unicellular cell structure of rounded or ellipsoidal shapes with a diameter of cell structures from 2 to 10 microns. The structure of the chlorella cell is represented as a thin shell, in the cytoplasm of which the nucleus with a decorated chloroplast is immersed. The optimal parameters for the intensive growth of chlorella microalgae were temperature values in the range of +27…+29°C. In such temperature values, chlorella microalgae showed the best results in terms of cell growth rate and in the values of its viability index. At the same time, the culture of chlorella cells, having the ability to outstrip cell growth, is able to maintain its systematic variety for a long time. In addition, it has been found that chlorella cells have a pronounced phototropism, expressed in responses to a light pulse and the ability to purposefully move towards it in the form of phototaxis. Further observations showed that the majority of chlorella cells in the visible field of micrometry were about 4–6 microns in size with an average quantitative content of about 4,5 million microalgae cell structures in one milliliter of nutrient (culture) medium. The indicator of the optical density of the studied chlorella cell culture after 14 days of growth in the nutrient medium increased by the end of observations by a little more than 2 times, which indicates a sufficiently high value of the viability of the cell structures of the Chlorella vulgaris Beijer. microalgae culture.