Bioenergy Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service,U.S. Department of Agriculture, 1815 N University Street, Peoria, IL, 61604, USA.
Appl Microbiol Biotechnol. 2020 Apr;104(8):3473-3492. doi: 10.1007/s00253-020-10434-0. Epub 2020 Feb 26.
The industrial yeast Saccharomyces cerevisiae has a plastic genome with a great flexibility in adaptation to varied conditions of nutrition, temperature, chemistry, osmolarity, and pH in diversified applications. A tolerant strain against 2-furaldehyde (furfural) and 5-hydroxymethyl-2-furaldehyde (HMF) was successfully obtained previously by adaptation through environmental engineering toward development of the next-generation biocatalyst. Using a time-course comparative transcriptome analysis in response to a synergistic challenge of furfural-HMF, here we report tolerance phenotypes of pathway-based transcriptional profiles as components of the adapted defensive system for the tolerant strain NRRL Y-50049. The newly identified tolerance phenotypes were involved in biosynthesis superpathway of sulfur amino acids, defensive reduction-oxidation reaction process, cell wall response, and endogenous and exogenous cellular detoxification. Key transcription factors closely related to these pathway-based components, such as Yap1, Met4, Met31/32, Msn2/4, and Pdr1/3, were also presented. Many important genes in Y-50049 acquired an enhanced transcription background and showed continued increased expressions during the entire lag phase against furfural-HMF. Such signature expressions distinguished tolerance phenotypes of Y-50049 from the innate stress response of its progenitor NRRL Y-12632, an industrial type strain. The acquired yeast tolerance is believed to be evolved in various mechanisms at the genomic level. Identification of legitimate tolerance phenotypes provides a basis for continued investigations on pathway interactions and dissection of mechanisms of yeast tolerance and adaptation at the genomic level.
工业酵母酿酒酵母具有可塑性基因组,能够在营养、温度、化学、渗透压和 pH 值等各种条件下灵活适应,在各种应用中具有很大的灵活性。之前,通过环境工程适应,成功获得了一种能够耐受 2-糠醛(糠醛)和 5-羟甲基-2-糠醛(HMF)的耐受菌株,以开发下一代生物催化剂。通过对糠醛-HMF 的协同挑战进行时间过程比较转录组分析,我们报告了耐受菌株 NRRL Y-50049 适应防御系统的基于途径的转录谱成分的耐受表型。新鉴定的耐受表型涉及硫氨基酸生物合成超级途径、防御氧化还原反应过程、细胞壁反应以及内源性和外源性细胞解毒。与这些基于途径的成分密切相关的关键转录因子,如 Yap1、Met4、Met31/32、Msn2/4 和 Pdr1/3 也存在。在整个糠醛-HMF 迟滞期,Y-50049 中的许多重要基因获得了增强的转录背景,并表现出持续增加的表达。这种特征表达将 Y-50049 的耐受表型与工业型菌株 NRRL Y-12632 的先天应激反应区分开来。获得的酵母耐受性被认为是在基因组水平上通过各种机制进化而来的。鉴定有效的耐受表型为进一步研究途径相互作用以及在基因组水平上解析酵母耐受和适应的机制提供了基础。