Oleaginous yeast, cultured on second-generation lignocellulosic resources, has the potential to be a key part of the future energy sector. However, the multiple unit operations necessary to produce concentrated hydrolysates, with a minimum of fermentation inhibitors, limit the applicability to date. In this study, a simple microwave-assisted hydrothermal pre-treatment step of oak or beech sawdust was deployed to produce an oligosaccharide-rich hydrolysate. This was then catabolised by the oleaginous yeast, Metschnikowia pulcherrima, avoiding the need for costly enzymatic or further chemical steps in the processing. Up to 85% of the sawdust’s hemicelluloses could be solubilised under these conditions, and 8 g/L DCW yeast with a 42% lipid content produced. While a number of studies have demonstrated that oleaginous yeasts possess high inhibitor tolerance, using this real lignocellulosic hydrolysate, we demonstrate that lipid production is actually very sensitive to inhibitor and carbon availability, and the optimal system is not the one that gives the highest hydrolysate or cell biomass. Indeed, the yeast was shown to detoxify the inhibitors in the process, but at high inhibitor loading, this leads to very poor lipid production, especially at high furfural levels. These findings clearly highlight the importance of considering multiple variables when real, complex lignocellulosic media are involved, tuning process conditions based on the desired fermentation outcomes.

在第二代木质纤维素资源上培养的含油酵母菌有可能成为未来能源领域的重要组成部分。但是，生产浓缩水解产物所必需的多单元操作以及最少的发酵抑制剂限制了迄今为止的适用性。在这项研究中，部署了橡木或山毛榉木屑的简单微波辅助水热预处理步骤，以生产富含低聚糖的水解产物。然后，它被油性酵母Metschnikowia pulcherrima分解代谢，避免了加工过程中昂贵的酶促步骤或其他化学步骤。在这些条件下，最多可溶解木屑半纤维素的85％，并产生8 g / L DCW酵母，脂质含量为42％。尽管许多研究表明油质酵母具有很高的抑制剂耐受性，但使用这种真正的木质纤维素水解产物，我们证明脂质的产生实际上对抑制剂和碳的利用非常敏感，而最佳系统并不是提供最高水解产物或最佳水解能力的系统。细胞生物量。实际上，已显示酵母在该过程中使抑制剂解毒，但是在高抑制剂装载量下，这会导致脂质产生非常差，尤其是在高糠醛水平下。这些发现清楚地说明了在实际情况下考虑多个变量的重要性，