UVA treatment increases the degree of unsaturation in microalgal fatty acids and total carotenoid content in Nitzschia closterium(Bacillariophyceae)and Isochrysis zhangjiangensis(Chrysophyceae)
Regulation of carotenoid biosynthetic genes expression and carotenoid accumulation in the green alga Haematococcus pluvialis under nutrient stress conditions