The decline in fishery resources from the wild has led to an ever increasing focus on aquaculture in recent years. With increasing aquaculture of animal species, there is an increasing need for suitable microalgae in the production of these animals. However, cultivation of microalgae in expensive pure chemical media is one of the major challenges facing large-scale cultivation of microalgae. The present study investigated the suitability of aquaculture wastewater (AWW) supplemented with NPK (nitrogen:phosphorus:potassium) fertilizer as a cheap source of nutrient to cultivate a microalga Chlorella vulgaris (C. vulgaris). C. vulgaris with an initial cell density of 0.8 × 106 cells/mL was batch cultured in AWW supplemented with NPK at 0.1, 0.5, 1.0 g/L and BBM for 20 days under laboratory conditions using 2000 mL Erlenmeyer flasks. The proximate composition, chlorophyll, minerals, and vitamins analysis of C. vulgaris biomass were done using standard analytical methods. The highest values in optical density (4.872 ± 0.025), dry cell weight (2.858 ± 0.015 g/L), specific growth rate (0.2097 ± 0.0038 day–1), and biomass productivity (0.1701 ± 0.0007 g/L/day) were obtained in C. vulgaris grown in AWW + 1.0 NPK medium. The total chlorophyll, protein, lipid, and carbohydrate content of the microalgae biomass were in the range of 0.05–0.862%, 44.062–57.089%, 17.064–23.260%, and 15.217–21.896%, respectively. Furthermore, microalgae grown in AWW + 1.0 NPK showed good vitamin and mineral content compared to BBM grown alga. These findings indicated that the AWW + 0.1 NPK, AWW + 0.5 NPK, and AWW + 1.0 NPK are potential growth media for C. vulgaris cultivation and can replace the BBM medium, which is very expensive and less accessible to users.

中文翻译：

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用NPK肥料补充废水作为廉价养分活菜（小球藻）的来源。

野外渔业资源的减少导致近年来对水产养殖的关注日益增加。随着动物种类的水产养殖的增加，在这些动物的生产中对合适的微藻的需求增加。然而，在昂贵的纯化学介质中培养微藻是大规模培养微藻面临的主要挑战之一。本研究调查了补充NPK（氮：磷：钾）肥料作为廉价营养物来源的微藻小球藻（C. vulgaris）的水产养殖废水（AWW）的适用性。在实验室条件下，使用2000 mL锥形瓶，将初始细胞密度为0.8×106细胞/ mL的普通梭菌在补充有0.1、0.5、1.0 g / L NBP和BBM的AWW中分批培养20天。使用标准分析方法对寻常型梭状芽孢杆菌生物质的近成分，叶绿素，矿物质和维生素进行分析。光密度（4.872±0.025），干细胞重量（2.858±0.015 g / L），比生长速率（0.2097±0.0038天–1）和生物量生产率（0.1701±0.0007 g / L /天）的最大值分别为在AWW + 1.0 NPK培养基中生长的寻常梭状芽胞杆菌中获得。微藻生物量的总叶绿素，蛋白质，脂质和碳水化合物含量分别在0.05–0.862％，44.062–57.089％，17.064–23.260％和15.217–21.896％之间。此外，与BBM藻相比，在AWW + 1.0 NPK中生长的微藻显示出良好的维生素和矿物质含量。这些发现表明AWW + 0.1 NPK，AWW + 0.5 NPK和AWW + 1.0 NPK是C的潜在生长培养基。