To produce microbial lipids for biofuel production, carbohydrates and related compounds from biomass have been routinely utilized, yet amino acids (AA) from protein-rich wastes have been overlooked so far. We use the oleaginous yeast Cryptococcus curvatus ATCC 20509 as a lipid producer and evaluate the capacity for lipid production on proteinogenic AA individually or in designated blends under two-staged culture conditions. It was found that cellular lipid contents reached 48.8%, 44.5% and 29.0% when yeast cells were cultivated in media-contained AA blends with compositional profiles similar to those of sheep viscera, meat industry by-products and fish muscle, respectively, and that lipid coefficients were more than 0.10 g g⁻¹. Furthermore, cellular lipid contents were higher than 20% when most AA were used individually. High lipid coefficients of over 0.23 g g⁻¹ were observed when Pro, Trp or Leu were used as a substrate. Results also indicated that higher initial media pH or reduced phosphate concentration was beneficial for lipid production on AA. This work demonstrated the potential to use AA and related wastes as substrates for microbial lipid production by the yeast C. curvatus, which fit well with the protein-based biorefinery concept. Further efforts should be devoted to recognizing the metabolic features, identifying more robust lipid producer and optimizing lipid production processes.

为了生产用于生物燃料生产的微生物脂质，已经常规地利用了来自生物质的碳水化合物和相关化合物，但是迄今为止，来自富含蛋白质的废物中的氨基酸（AA）一直被忽视。我们使用产油酵母弯曲隐球菌ATCC 20509作为脂质生产商，并在两阶段培养条件下单独或以指定的混合物评估产蛋白AA的脂质生产能力。研究发现，在含有培养基的AA混合物中培养酵母细胞时，其细胞脂质含量分别达到48.8％，44.5％和29.0％，其组成特征分别类似于绵羊内脏，肉类副产品和鱼肉。脂质系数大于0.10 gg ^-1。此外，当大多数AA单独使用时，细胞脂质含量高于20％。当Pro，Trp或Leu用作底物时，观察到的高脂质系数超过0.23 g g ^-1。结果还表明，较高的初始培养基pH值或降低的磷酸盐浓度对AA上的脂质生产是有益的。这项工作证明了使用AA和相关废物作为曲霉酵母生产微生物脂质的底物的潜力，这与基于蛋白质的生物精炼概念非常吻合。应致力于识别新陈代谢特征，确定更健壮的脂质生产者并优化脂质生产过程。