Microalga Chlorella vulgaris 211/11j as a promising strain for low temperature climate

Microalgae are regarded as a promising source of renewable energy and high-value compounds. To date most large-scale microalgae cultivation is located in hot low-latitude regions; however, high temperature and high solar intensity create a risk of overheating during summer days. Here we explore the option of microalgae cultivation in low temperature regions. The impact of low temperature on microalgae growth is rarely considered in studied species and strains. To assess the optimum temperature and to test the ability to grow in low temperatures, we tested the effect of environmental temperatures ranging from 8 to 32 °C on the growth of the green microalga Chlorella vulgaris 211/11j. This strain was selected as a candidate strain for outdoor cultivation after an extensive literature review. The results indicate that C. vulgaris 211/11j has a lower optimal growth temperature than some other strains of C. vulgaris and exhibits optimal growth over a wide temperature range from 20 to 28 °C. Moreover, we demonstrate that the strain can grow successfully at low environmental temperatures that are below the optimum of this strain. Therefore, we suggest C. vulgaris 211/11j as a potential strain for cultivation in outdoor open ponds exposed to changing environmental temperatures in cooler climate regions.