Efficient microalgal lipid production driven by salt stress and phytohormones synergistically

In this study, a novel method of coupling phytohormones with saline wastewater was proposed to drive efficient microalgal lipid production. All the six phytohormones effectively promoted microalgae growth in saline wastewater, and further increased the microalgal lipid content based on salt stress, so as to achieve a large increase in microalgal lipid productivity. Among the phytohormones used, abscisic acid had the most significant promoting effect. Under the synergistic effect of 20 g/L salt and 20 mg/L abscisic acid, the microalgal lipid productivity reached 3.7 times that of the control. Transcriptome analysis showed that differentially expressed genes (DEGs) of microalgae in saline wastewater were mainly up-regulated under the effects of phytohormones except brassinolide. Common DEGs analysis showed that phytohormones all regulated the expression of genes related to DNA repair and substance synthesis. In conclusion, synergistic effect of salt stress and phytohormones can greatly improve the microalgal lipid production efficiency.

Automated summary

A novel method of coupling phytohormones with saline wastewater was proposed to enhance microalgal lipid production. All six phytohormones effectively promoted microalgae growth and increased lipid content under salt stress, resulting in a significant increase in microalgal lipid productivity. Among the phytohormones, abscisic acid had the most prominent promoting effect. Synergistic effect of 20 g/L salt and 20 mg/L abscisic acid led to a 3.7-fold increase in microalgal lipid productivity compared to the control. Transcriptome analysis revealed that differentially expressed genes (DEGs) in microalgae were mainly up-regulated by phytohormones, except brassinolide. Common DEGs analysis showed that phytohormones regulated genes related to DNA repair and substance synthesis. In conclusion, the synergistic effect of salt stress and phytohormones greatly improves microalgal lipid production efficiency.