School of Chemical Engineering and Technology, Hebei University of Technology, No.5340 Xiping Road, Beichen District, Tianjin, 300401, People's Republic of China.
World J Microbiol Biotechnol. 2024 Oct 15;40(11):349. doi: 10.1007/s11274-024-04150-4.
Isobutanol represents a promising second-generation biofuel. Saccharomyces cerevisiae can produce minor quantities of isobutanol as a byproduct. Increasing yeast tolerance to isobutanol is a crucial step toward achieving higher production levels. Previously, we discovered that expression of the srp40 gene could increase S. cerevisiae isobutanol tolerance. In this study, we explored the impact of overexpressing srp40 on isobutanol production. We used the CEN/ARS plasmid YCplac22-srp40 to overexpress srp40 in S. cerevisiae strain W303-1A. The resulting strain was named W303-1A-srp40. We subsequently performed metabolic engineering of isobutanol synthesis by overexpressing ILV2, ILV3 and ARO10 in W303-1 A-srp40. The resulting strain was named 303V2V3A10-22-srp40. Our findings revealed that, compared with the control strain, the 303V2V3A10-22-srp40 strain amplified isobutanol production by 50%. A transcriptome analysis revealed that upregulated genes associated with aminoacyl-tRNA biosynthesis or downregulated genes associated with phenylalanine, tyrosine, and tryptophan biosynthesis might yield increased isobutanol production in 303V2V3A10-22-srp40. Moreover, the decreases in the biosynthesis of amino acids and oxidative phosphorylation might play pivotal roles in the increased isobutanol tolerance of strain W303-1A-srp40. In summary, the overexpression of srp40 could increase isobutanol production and tolerance in S. cerevisiae. This study offers novel insights regarding strategies for increasing isobutanol production.
异丁醇是一种很有前途的第二代生物燃料。酿酒酵母可以少量生产异丁醇作为副产物。提高酵母对异丁醇的耐受性是实现更高生产水平的关键步骤。以前，我们发现 srp40 基因的表达可以提高酿酒酵母对异丁醇的耐受性。在这项研究中，我们探讨了过表达 srp40 对异丁醇生产的影响。我们使用 CEN/ARS 质粒 YCplac22-srp40 在酿酒酵母菌株 W303-1A 中过表达 srp40。得到的菌株命名为 W303-1A-srp40。随后，我们通过过表达 ILV2、ILV3 和 ARO10 对异丁醇合成进行代谢工程改造，在 W303-1A-srp40 中。得到的菌株命名为 303V2V3A10-22-srp40。我们的研究结果表明，与对照菌株相比，303V2V3A10-22-srp40 菌株的异丁醇产量增加了 50%。转录组分析表明，与苯丙氨酸、酪氨酸和色氨酸生物合成相关的上调基因或与亮氨酸、异亮氨酸和缬氨酸生物合成相关的下调基因可能导致 303V2V3A10-22-srp40 中异丁醇产量增加。此外，氨基酸生物合成和氧化磷酸化的减少可能在 W303-1A-srp40 菌株异丁醇耐受性增加中发挥关键作用。总之，srp40 的过表达可以提高酿酒酵母中异丁醇的产量和耐受性。这项研究为提高异丁醇产量提供了新的策略。
