PONE-D-23-03510R3_FTC

Microalgae biomass is regarded as a promising feedstock for biodiesel production. The biomass lipid content and fatty acids composition are among the main selective criteria when screening microalgae strains for biodiesel production. In this study, three strains of Chlorella microalgae (C. kessleri, C. sorokiniana, C. vulgaris) were cultivated nutrient media with different nitrogen contents, and on a medium with the addition of dairy wastewater. Moreover, microalgae grown on dairy wastewater allowed the removal of azote and phosphorous. The removal efficiency of 90%, 53% and 95% of ammonium nitrogen, total nitrogen and phosphate ions, respectively, were reached. The efficiency of wastewater treatment from inorganic carbon was 55%, while the maximum growth of biomass was achieved. All four samples of microalgae had a similar fatty acid profile. Palmitic acid (C16:0) was the most abundant saturated fatty acid (SFA), and is suitable for the production of biodiesel. The main unsaturated fatty acids (UFA) present in the samples were oleic acid (C18:1 n9); linoleic acid (C18:2 n6) and alpha-linolenic acid (C18:3 n3), which belong to omega-9, omega-6, omega-3, respectively.

微藻生物质被视为生物柴油生产的极具潜力的原料。在筛选用于生物柴油生产的微藻菌株时，生物质脂质含量与脂肪酸组成是核心筛选指标之一。本研究选取3株小球藻属（Chlorella）微藻（分别为C. kessleri、C. sorokiniana、C. vulgaris），分别接种于不同氮浓度的培养基以及添加乳类废水的培养基中培养。此外，在乳类废水中培养的微藻可实现氮与磷的去除，对氨氮、总氮以及磷酸根离子的去除率分别达到90%、53%和95%；对废水中无机碳的去除率为55%，同时实现了生物质的最大生物量积累。所有4组微藻样本的脂肪酸组成谱均较为相似。棕榈酸（C16:0）是含量最高的饱和脂肪酸（SFA），适用于生物柴油的生产。样本中主要的不饱和脂肪酸（UFA）为油酸（C18:1 n9）、亚油酸（C18:2 n6）以及α-亚麻酸（C18:3 n3），分别隶属于ω-9、ω-6和ω-3系列脂肪酸。