<![CDATA[Graphical Abstract Highlight Research 1. Production of Haematococcus microalgae using optimum Walne fertilizer media in snakehead fish farming waste. 2. Utilization of UV and/or ethanol to increase lipid production in Haematococcus. 3. Changes in the fatty acid composition of Haematococcus microalgae after UV and/or ethanol treatment. 4. Haematococcus protein levels decrease when treated with UV and/or ethanol. Abstract Haematococcus pluvialis is a single-celled green microalga that is a possible source of bioactive compound. H. pluvialis cultivation mostly employs pro-analysis media, with organic components frequently limited. The use of wastewater from snakehead fish rearing to cultivate H. pluvialis to produce necessary fatty acids and amino acids has never been investigated. Environmental stress-induced physical treatment is likely to boost lipid production. There have been very few investigations on fatty acid composition in lipid synthesis from H. pluvialis cultivated in fish-rearing effluent. The purpose of this work was to assess the potential of snakehead fish wastewater (SFWW) as a culture medium for H. pluvialis, as well as to examine the fatty acid and amino acid properties of the microalga after exposure to UV and ethanol stress during the stationary phase. The study consisted of two sequential experiments: optimizing growth to determine the optimal Walne medium supplementation for H. pluvialis growth in SFWW, and inducing stress to assess the effects of ethanol and UV irradiation on H. pluvialis biochemical. The results showed that the SFWW medium supports the growth of H. pluvialis, with addition of 0.75 ml L-1 Walne medium achieving the highest densities (28.13±0.38 ×106 cells mL−1). Ethanol and UV are excellent at inducing stress in H. pluvialis. The maximum lipid percentage was seen in the Ethanol-UV treatment, but this stress also reduced H. pluvialis protein content. SFWW can be used to cultivate H. pluvialis by supplementing Walne. Further research is needed on treatments that can increase long-chain unsaturated fatty acids.]]>
