Several types of green photosynthetic microalgae can grow through the process of heterotrophic growth in the dark with the help of a carbon source instead of the usual light energy. Heterotrophic growth overcomes important limitations in the production of valuable products from microalgae, such as the reliance on light, which complicates the process, raises costs, and lowers the yield of potentially useful products. The present study was conducted to explore the potential growth of green microalga Scenedesmus obliquus under mixotrophic and heterotrophic conditions utilizing Disperse orange 2RL Azo dye as a carbon source to produce a high lipid content and the maximum dye removal percentage. After 7 days of algal growth with dye under mixotrophic and heterotrophic conditions with varying pH levels (5, 7, 9, and 11), KNO₃ concentrations (1, 1.5, 2, and 3 g/L), and dye concentrations (20, 40, and 60 ppm); dye removal percentage, algal dry weight, and lipid content were determined. The results showed that the highest decolorization of Disperse orange 2RL Azo dye (98.14%) was attained by S. obliquus in heterotrophic medium supplemented with glucose at the optimal pH 11 when the nitrogen concentration was 1 g/L and the dye concentration was 20 ppm. FT-IR spectroscopy of the dye revealed differences in peaks position and intensity before and after algal treatment. S. obliquus has a high concentration of oleic acid, which is enhanced when it is grown with Disperse orange 2RL Azo dye, making it ideal for production of high-quality biodiesel. In general, and in the vast majority of instances, heterotrophic cultivation is substantially less expensive, easier to set up, and requires less maintenance than mixotrophic cultivation. Heterotrophic cultivation allows for large-scale applications such as separate or mixed wastewater treatment along with biofuel production.

几种类型的绿色光合微藻可以在碳源而不是通常的光能的帮助下通过黑暗中的异养生长过程生长。异养生长克服了微藻生产有价值产品的重要限制，例如对光的依赖，这使过程复杂化，增加了成本，并降低了潜在有用产品的产量。本研究旨在探索绿色微藻斜生栅藻的潜在生长在混养和异养条件下，利用分散橙 2RL 偶氮染料作为碳源以产生高脂质含量和最大染料去除百分比。在不同 pH 水平（5、7、9 和 11）、KNO ₃浓度（1、1.5、2 和 3 g/L）和染料浓度（20 、40 和 60 ppm）；测定染料去除百分比、藻类干重和脂质含量。结果表明， S. obliquus对分散橙 2RL 偶氮染料的脱色率最高 (98.14%)当氮浓度为 1 g/L 且染料浓度为 20 ppm 时，在最佳 pH 11 下补充葡萄糖的异养培养基中。染料的 FT-IR 光谱揭示了藻类处理前后峰位置和强度的差异。S. obliquus具有高浓度的油酸，当它与分散橙 2RL 偶氮染料一起生长时，油酸会得到增强，非常适合生产高质量的生物柴油。总的来说，在绝大多数情况下，异养栽培比混合营养栽培成本低得多，更容易建立，需要的维护也更少。异养培养允许大规模应用，例如单独或混合废水处理以及生物燃料生产。