Acid whey, a byproduct in cheese and yogurt production, demands high costs in disposal at large quantities. Nonetheless, it contains abundant sugars and nutrients that can potentially be utilized by microorganisms. Here we report a novel platform technology that converts acid whey into value-added products using Yarrowia lipolytica. Since wild type strains do not assimilate lactose, a major carbon source in whey, a secreted β-galactosidase was introduced. Additionally, to accelerate galactose metabolism, we overexpressed the relevant native four genes of the Leloir pathway. The engineered strain could achieve rapid total conversion of all carbon sources in acid whey, producing 6.61 g/L of fatty acids (FAs) with a yield of 0.146 g-FAs/g-substrates. Further engineering to introduce an omega-3 desaturase enabled the synthesis of α-linolenic acid from acid whey, producing 10.5 mg/gDCW within a short fermentation time. Finally, PEX10 knockout in our platform strain was shown to minimize hyphal formation in concentrated acid whey cultures, greatly improving fatty acid content. These results demonstrate the feasibility of using acid whey as a previously untapped resource for biotechnology.

奶酪和酸奶生产中的副产品酸乳清需要大量处置的高成本。但是，它含有丰富的糖和营养成分，可被微生物潜在利用。在这里，我们报告了一种新颖的平台技术，该技术利用解脂耶氏酵母将酸乳清转化为增值产品。由于野生型菌株不能吸收乳糖（乳清中的主要碳源），因此引入了分泌的β-半乳糖苷酶。此外，为了加速半乳糖代谢，我们过表达了Leloir途径的相关天然四个基因。该工程菌株可以实现酸乳清中所有碳源的快速总转化，产生6.61 g / L的脂肪酸（FAs），产量为0.146 g-FAs / g底物。引入omega-3去饱和酶的进一步工程设计可从酸乳清合成α-亚麻酸，在短发酵时间内产生10.5 mg / gDCW。最后，我们的平台菌株中的PEX10基因敲除被证明可以最大程度地减少浓酸乳清培养物中的菌丝形成，从而大大提高了脂肪酸含量。