Productivity and morphometric parameters of the microalga Dunaliella salina IBSS-2 under pilot cultivation in continental mid-latitude climate in spring

Abstract

In this study, we aimed to investigate the taxonomy and various characteristics of Dunaliella salina IBSS-2 strain and describe its cultivation potential in mid-latitude climate during springtime. In addition, our analysis confirmed the essentiality of combining morphological, physiological, and other characteristics when identifying new species and strains of the genus Dunaliella, along with the molecular marker (internal transcribed spacer (ITS) of rDNA gene). The pilot cultivation of microalgae during the springtime in the south of Russia demonstrated that the climatic conditions of this region allow D. salina cultivation for biomass accumulation during this season, highlighting light and temperature conditions as the main factors determining the growth rate of D.salina. A two-fold increase in daily insolation and, consequently, in temperature in April resulted in a more than three-fold increase in productivity of D.salina culture. The maximum productivity of D. salina both in April and May was comparable and reached 2gm-2day-1, and the total yield for 8-10days was about 14.5-16gm-2. The additional CO2 supply into the D. salina culture did not show any significant effect on its growth rate; however, it contributed to maintaining the diversity of morphometric characteristics over a longer period of time. Changes in the morphological and morphometric characteristics of algal cells, including size reduction, were observed during the batch cultivation. Thus, the production potential of the green carotenogenic microalga D. salina was determined in the springtime, which allows expanding the seasonal interval of its cultivation in temperate latitudes.