New Papiliotrema laurentii UFV-1 strains with improved acetic acid tolerance selected by adaptive laboratory evolution
New Papiliotrema laurentii UFV-1 strains with improved acetic acid tolerance selected by adaptive laboratory evolution
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DOI：
10.1016/j.fgb.2022.103765
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发表时间：
2022-12-19
影响因子：
3
通讯作者：
Silveira, W. B.
中科院分区：
文献类型：
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作者：
Almeida, E. L. M.;Ventorim, R. Z.;Silveira, W. B.
从木质纤维素生物质生产酵母油会受到预处理步骤中形成的抑制剂（主要是乙酸）的影响。在此，我们应用适应性实验室进化（ALE）来选择P. laurentii UFV-1的三个耐乙酸菌株（ATS）。随着进化出现了不同的表型。 ATS II 在没有乙酸的情况下表现出权衡，表明它表现出对有机酸生长的特殊表型耐受性。另一方面，ATS I 和 ATS III 呈现与通才行为相关的表型。 ATS I 被认为是最有前途的进化菌株，因为它在所有测试条件下都显示出产油表型。因此，我们应用全基因组测序来检测该菌株在 ALE 期间出现的突变。我们发现编码涉及不同细胞功能的蛋白质的基因发生了改变，包括多药耐药性（MDR）转运蛋白、能量代谢、解毒、辅酶回收和细胞包膜重塑。为了评估乙酸应激反应，在不存在和存在乙酸的情况下以恒化器模式培养亲本菌株和 ATS I 菌株。与 ATS I 相比，亲本菌株在乙酸胁迫条件下呈现出细胞包膜和细胞大小的变化。此外，亲本菌株和 ATS I 在乙酸同化方面存在差异。与亲本菌株相反，无论乙酸胁迫如何，ATS I 的不饱和脂肪酸含量均有所增加，这可能与对乙酸的耐受性提高有关。总而言之，这些结果提供了对 ATS I 所表现出的乙酸耐受性的机制以及 P. laurentii 对这种应激条件的反应的深入了解。
The production of yeast oil from lignocellulosic biomasses is impaired by inhibitors formed during the pre-treatment step, mainly acetic acid. Herein, we applied Adaptive Laboratory Evolution (ALE) to select three Acetic acid Tolerant Strains (ATS) of P. laurentii UFV-1. Different phenotypes emerged alongside evolution. The ATS II presented trade-offs in the absence of acetic acid, suggesting that it displays a specialized phenotype of tolerance to growth on organic acids. On the other hand, ATS I and ATS III presented phenotypes associated with the behavior of generalists. ATS I was considered the most promising evolved strain as it displayed the oleaginous phenotype in all conditions tested. Thus, we applied whole-genome sequencing to detect the mutations that emerged in this strain during the ALE. We found alterations in genes encoding proteins involved in different cellular functions, including multidrug resistance (MDR) transporters, energy metabolism, detoxification, co-enzyme recycling, and cell envelope remodeling. To evaluate acetic acid stress responses, both parental and ATS I strains were cultivated in chemostat mode in the absence and presence of acetic acid. In contrast to ATS I, the parental strain presented alterations in the cell envelope and cell size under acetic acid stress conditions. Furthermore, the parental strain and the ATS I presented differences regarding acetic acid assimilation. Contrary to the parental strain, the ATS I displayed an increase in unsaturated fatty acid content irrespective of acetic acid stress, which might be related to improved tolerance to acetic acid. Altogether, these results provided insights into the mechanisms involved with the acetic acid tolerance displayed by ATS I and the responses of P. laurentii to this stressful condition.