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 similar to 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 (similar to 50%) and C20:5 (similar to 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.

Automated summary

This study reported a new strain of Eustigmatophyceae, Vischeria sp. WL1, with high oil content suitable for oil production. Different nitrogen sources and salt stress treatments were explored, and it was found that 4.5 mM peptone-N and 0.3 M NaCl had positive effects on oil productivity.