Keerthiraju Ethiraju, Du Chenyu, Tucker Gregory, Greetham Darren
Sutton Bonington Campus, University of Nottingham, School of Biosciences, Loughborough LE12 5RD, UK.
School of Applied Sciences, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, UK.
Microorganisms. 2019 Nov 18;7(11):575. doi: 10.3390/microorganisms7110575.
Industrial production of bioethanol from lignocellulosic materials (LCM's) is reliant on a microorganism being tolerant to the stresses inherent to fermentation. Previous work has highlighted the importance of a cytochrome oxidase chaperone gene () in improving yeast tolerance to acetic acid, a common inhibitory compound produced during pre-treatment of LCM's. The presence of acetic acid has been shown to induce oxidative stress and programmed cell death, so the role of in oxidative stress was determined. Analysis using flow cytometry revealed that COX20 expression was associated with reduced levels of reactive oxygen species (ROS) in hydrogen peroxide and metal-induced stress, and there was a reduction in apoptotic and necrotic cells when compared with a strain without COX20. Results on the functionality of COX20 have revealed that overexpression of COX20 induced respiratory growth in Δimp1 and Δcox18, two genes whose presence is essential for yeast respiratory growth. COX20 also has a role in protecting the yeast cell against programmed cell death.
从木质纤维素材料（LCM）工业生产生物乙醇依赖于一种能够耐受发酵固有应激的微生物。先前的研究强调了细胞色素氧化酶伴侣基因（）在提高酵母对乙酸耐受性方面的重要性，乙酸是LCM预处理过程中产生的一种常见抑制性化合物。已表明乙酸的存在会诱导氧化应激和程序性细胞死亡，因此确定了该基因在氧化应激中的作用。使用流式细胞术分析表明，在过氧化氢和金属诱导的应激中，COX20的表达与活性氧（ROS）水平降低相关，与没有COX20的菌株相比，凋亡和坏死细胞减少。关于COX20功能的结果表明，COX20的过表达诱导了Δimp1和Δcox18中的呼吸生长，这两个基因的存在对酵母呼吸生长至关重要。COX20在保护酵母细胞免受程序性细胞死亡方面也发挥作用。
