The use of microalgal biomass as feedstock for biofuels has been discussed for decades as it provides a sustainable approach to producing fuels for the future. Nonetheless, its feasibility has not been established yet and various aspects of biomass applications such as CO₂ biofixation should also be explored. Therefore, in this study, the CO₂ biofixation and lipid/carbohydrate production potential of Chlorella sp. ABC-001 were examined under various nitrogen concentrations. The highest biomass productivity and CO₂ biofixation rate of 0.422 g/l/d and 0.683 g/l/d, respectively, were achieved under a nitrogen-rich condition (15 mM nitrate). Carbohydrate content was generally proportional to initial nitrate concentration and showed the highest value of 41.5% with 15 mM. However, lipid content showed an inverse relationship with nitrogen supplementation and showed the highest value of 47.4% with 2.5 mM. In consideration as feedstock for biofuels (bioethanol, biodiesel, and biogas), the sum of carbohydrate and lipid contents were examined and the highest value of 79.6% was achieved under low nitrogen condition (2.5 mM). For lipid-based biofuel production, low nitrogen supplementation should be pursued. However, considering the lower feasibility of biodiesel, pursuing CO₂ biofixation and the production of carbohydrate-based fuels under nitrogenrich condition might be more rational. Thus, nitrogen status as a cultivation strategy must be optimized according to the objective, and this was confirmed with the promising alga Chlorella sp. ABC-001.

中文翻译：

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氮补充状态对有前途的微藻小球藻 CO2 生物固定和生物燃料生产的影响。ABC-001。

几十年来，人们一直在讨论使用微藻生物质作为生物燃料的原料，因为它为未来生产燃料提供了一种可持续的方法。尽管如此，其可行性尚未确定，还应探索生物质应用的各个方面，例如 CO _{2生物固定。}因此，在这项研究中，小球藻的 CO ₂生物固定和脂质/碳水化合物生产潜力。在各种氮浓度下对 ABC-001 进行了检查。最高的生物质生产率和 CO ₂在富氮条件（15 mM 硝酸盐）下，生物固定率分别达到 0.422 g/l/d 和 0.683 g/l/d。碳水化合物含量通常与初始硝酸盐浓度成正比，在 15 mM 时最高值为 41.5%。然而，脂质含量与氮的补充呈反比关系，最高值为 47.4%，为 2.5 mM。考虑作为生物燃料（生物乙醇、生物柴油和沼气）的原料，检查了碳水化合物和脂质含量的总和，在低氮条件下（2.5 mM）达到了 79.6% 的最高值。对于基于脂质的生物燃料生产，应追求低氮补充。但考虑到生物柴油可行性较低，追求CO ₂在富氮条件下进行生物固定和生产碳水化合物燃料可能更为合理。因此，作为栽培策略的氮状态必须根据目标进行优化，这一点在有前途的藻类小球藻中得到了证实。ABC-001。