The negative effects of lignocellulose-derived inhibitors such as acetic acid and furaldehydes on microbial metabolism constitute a significant drawback to the usage of biomass feedstocks for the production of fuels and chemicals. The yeast Pichia pastoris has shown a great biotechnological potential for producing heterologous proteins and renewable chemicals. Despite its relevance, the performance of P. pastoris in presence of lignocellulose-derived inhibitors remains unclear. In this work, our results show for the first time the dose-dependent response of P. pastoris to acetic acid, furaldehydes (HMF and furfural), and sugarcane biomass hydrolysate, both at physiological and transcriptional levels. The yeast was able to grow in synthetic media with up to 6 g.L⁻¹ acetic acid, 1.75 g.L⁻¹ furaldehydes or hydrolysate diluted to 10% (v/v). However, its metabolism was completely hindered in presence of hydrolysate diluted to 30% (v/v). Additionally, the yeast was capable to co-consume acetic acid and glucose. At the transcriptional level, P. pastoris response to lignocellulose-derived inhibitors relays on the up-regulation of genes related to transmembrane transport, oxidoreductase activities, RNA processing, and the repression of pathways related to biosynthetic processes and central carbon metabolism. These results demonstrate a polygenetic response that involves detoxification activities, and maintenance of energy and cellular homeostasis. In this context, ALD4, OYE3, QOR2, NTL100, YCT1, and PPR1 were identified as target genes to improve P. pastoris tolerance. Altogether, this work provides valuable insights into the P. pastoris stress tolerance, which can be useful to expand its use in different bioprocesses.

木质纤维素衍生的抑制剂（例如乙酸和糠醛）对微生物代谢的负面影响构成了使用生物质原料生产燃料和化学品的重大缺陷。酵母巴斯德毕赤酵母已经显示出用于制造异源蛋白质和可再生的化学物质有很大生物技术的潜力。尽管具有相关性，但是在木质纤维素衍生的抑制剂存在下巴斯德毕赤酵母的性能仍不清楚。在这项工作中，我们的结果首次显示了巴斯德毕赤酵母的剂量依赖性反应。在生理和转录水平上均转化为乙酸，糠醛（HMF和糠醛）和甘蔗生物质水解产物。酵母能够在含有最多6 gL ^-1乙酸，1.75 gL ^-1糠醛或稀释至10％（v / v）的水解产物的合成培养基中生长。然而，在稀释至30％（v / v）的水解产物存在下，其代谢被完全阻碍。另外，酵母能够共同消耗乙酸和葡萄糖。在转录水平上，巴斯德毕赤酵母对木质纤维素衍生抑制剂的反应依赖于与跨膜转运，氧化还原酶活性，RNA加工以及与生物合成过程和中央碳代谢有关的通路的抑制相关基因的上调。这些结果证明了涉及排毒活动以及维持能量和细胞稳态的多基因反应。在这种情况下，ALD4，OYE3，QOR2，NTL100，YCT1和PPR1被鉴定为提高巴斯德毕赤酵母耐受性的靶基因。总之，这项工作提供了对巴斯德毕赤酵母胁迫耐受性的宝贵见解，这对于扩大其在不同生物过程中的用途可能是有用的。