To meet the increasing demands of the growing population and to cope with the challenges of global change, both the production of biological feedstock and the recovery of recyclable natural resources play a critical role. Microalgal biomass is a promising source of renewable multifunctional feedstock, but the production is costly and requires large amounts of water. Here, we explored the potential of using wastewater as culture medium to lower the economic and environmental costs of microalgae biomass production and evaluated its valorization opportunities for animal feed production. As a proof of principle, we show that Chlorella sorokiniana can be cultivated on poultry wastewater, with a 83% and 113% increase in productivity when wastewater was first 50% diluted with tap water or standard growth medium, respectively. Wastewater sterilization before use enhanced algal growth with 36-118%, but only when wastewater was 25-50% diluted with standard medium. In contrast, it offered no additional benefits when dilutions were made with tap water or when wastewater was not diluted. At the end of the 22-days experiment, a maximum biomass of 0.8-1.9 g L-1 was reached for algae grown on wastewater. The produced biomass had a high macronutrient content, and the heavy metal content was below maximum limits for use in animal feed. Likewise, the tested pathogen groups were reduced until below safety norms for feed production after algal growth in unsterilized 50% wastewater (diluted with tap water). Overall, these findings add to our growing knowledge on the cultivation of microalgae on wastewater and its valorization opportunities, paving the way for a more sustainable use and reuse of resources.

中文翻译：

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废物是新财富——从家禽废水中回收资源用于多功能微藻原料

为了满足不断增长的人口日益增长的需求并应对全球变化的挑战，生物原料的生产和可回收自然资源的回收都发挥着至关重要的作用。微藻生物质是一种很有前途的可再生多功能原料来源，但生产成本高昂且需要大量水。在这里，我们探索了使用废水作为培养基降低微藻生物质生产的经济和环境成本的潜力，并评估了其在动物饲料生产中的增值机会。作为原理证明，我们表明，当废水首先用自来水或标准生长培养基稀释 50% 时，可以在家禽废水中培养 Chlorella sorokiniana，生产力分别提高 83% 和 113%。使用前对废水进行灭菌可促进藻类生长 36-118%，但仅当废水用标准培养基稀释 25-50% 时。相比之下，当用自来水稀释或不稀释废水时，它没有提供额外的好处。在为期 22 天的实验结束时，在废水中生长的藻类达到了 0.8-1.9 g L-1 的最大生物量。生产的生物质具有高常量营养素含量，重金属含量低于用于动物饲料的最大限值。同样，在未消毒的 50% 废水（用自来水稀释）中藻类生长后，测试的病原体组减少，直到低于饲料生产的安全标准。总体而言，这些发现增加了我们对废水中微藻培养及其增值机会的日益增长的知识，