Effects of nitrogen source and NaCl stress on oil production in Vischeria sp. WL1 (Eustigmatophyceae) isolated from dryland biological soil crusts in China.

A new strain of Eustigmatophyceae, Vischeria sp. WL1, which accumulates oil droplets in the cells, was isolated from a large biological soil crust in the arid steppes of north-western China. Its growth and oil productivity were explored using nitrate–N and peptone-N sources, as well as salt stress treatment. Compared to the commonly used ~ 18.0 mM nitrate–N, 4.5 mM nitrate–N was found to be relatively cost-effective for oil production, and 4.5 mM peptone-N was much more effective. After 24 days of cultivation, the biomass increased up to 7.5 times the initial biomass and the oil yield reached 1.13 g L−1 for the 4.5 mM peptone-N condition. In addition, supplementation of 0.3 M NaCl in the medium was found to enhance the oil productivity, while 3.0 M NaCl treatment facilitated the obtaining of relatively pure oil, removing more than 95% of the cellular pigments prior to oil extraction. The oils produced are characterized by high contents of C16:1 (~ 50%) and C20:5 (~ 10%) fatty acids, implying that they may serve as ideal biodiesel feedstocks or nutritional supplements. In general, this study reported a new dryland microalgal strain and its biotechnological potential in the production of oils with biofuel or edible value. [ABSTRACT FROM AUTHOR]