Division of Industrial Biotechnology, Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden.
Division of Systems and Synthetic Biology, Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden.
Appl Environ Microbiol. 2024 May 21;90(5):e0233023. doi: 10.1128/aem.02330-23. Epub 2024 Apr 8.
Improving our understanding of the transcriptional changes of during fermentation of lignocellulosic hydrolysates is crucial for the creation of more efficient strains to be used in biorefineries. We performed RNA sequencing of a CEN.PK laboratory strain, two industrial strains (KE6-12 and Ethanol Red), and two wild-type isolates of the LBCM collection when cultivated anaerobically in wheat straw hydrolysate. Many of the differently expressed genes identified among the strains have previously been reported to be important for tolerance to lignocellulosic hydrolysates or inhibitors therein. Our study demonstrates that stress responses typically identified during aerobic conditions such as glutathione metabolism, osmotolerance, and detoxification processes also are important for anaerobic processes. Overall, the transcriptomic responses were largely strain dependent, and we focused our study on similarities and differences in the transcriptomes of the LBCM strains. The expression of sugar transporter-encoding genes was higher in LBCM31 compared with LBCM109 that showed high expression of genes involved in iron metabolism and genes promoting the accumulation of sphingolipids, phospholipids, and ergosterol. These results highlight different evolutionary adaptations enabling to strive in lignocellulosic hydrolysates and suggest novel gene targets for improving fermentation performance and robustness.
The need for sustainable alternatives to oil-based production of biochemicals and biofuels is undisputable. is the most commonly used industrial fermentation workhorse. The fermentation of lignocellulosic hydrolysates, second-generation biomass unsuited for food and feed, is still hampered by lowered productivities as the raw material is inhibitory for the cells. In order to map the genetic responses of different strains, we performed RNA sequencing of a CEN.PK laboratory strain, two industrial strains (KE6-12 and Ethanol Red), and two wild-type isolates of the LBCM collection when cultivated anaerobically in wheat straw hydrolysate. While the response to inhibitors of has been studied earlier, this has in previous studies been done in aerobic conditions. The transcriptomic analysis highlights different evolutionary adaptations among the different and suggests novel gene targets for improving fermentation performance and robustness.
提高我们对木质纤维素水解物发酵过程中 转录变化的理解，对于创造更有效的菌株用于生物炼制厂至关重要。我们对 CEN.PK 实验室菌株、两个工业菌株（KE6-12 和 Ethanol Red）以及 LBCM 收集的两个野生型分离株进行了 RNA 测序，这些菌株在小麦秸秆水解物中进行厌氧培养。在菌株之间鉴定的许多差异表达基因以前曾被报道对木质纤维素水解物或其中的抑制剂的耐受性很重要。我们的研究表明，通常在好氧条件下识别的应激反应，如谷胱甘肽代谢、耐渗性和解毒过程，对于厌氧过程也很重要。总体而言，转录组反应在很大程度上取决于菌株，我们专注于 LBCM 菌株转录组的相似性和差异。与表现出高水平参与铁代谢和促进鞘脂、磷脂和麦角固醇积累的基因表达的 LBCM109 相比，LBCM31 中糖转运蛋白编码基因的表达更高。这些结果突出了不同的进化适应，使 能够在木质纤维素水解物中努力生长，并为改善发酵性能和稳健性提出了新的基因靶标。
无可争议的是，需要可持续的替代品来替代以石油为基础的生化和生物燃料生产。 是最常用的工业发酵工作马。木质纤维素水解物的发酵，第二代不适合食物和饲料的生物质，仍然受到生产力下降的阻碍，因为原材料对细胞具有抑制作用。为了绘制不同 菌株的遗传反应图谱，我们对 CEN.PK 实验室菌株、两个工业菌株（KE6-12 和 Ethanol Red）以及 LBCM 收集的两个野生型分离株进行了 RNA 测序，这些菌株在小麦秸秆水解物中进行厌氧培养。虽然 对抑制剂的反应已经在早期进行了研究，但在以前的研究中，这是在好氧条件下进行的。转录组分析突出了不同菌株之间的不同进化适应，并为提高发酵性能和稳健性提出了新的基因靶标。
