Mota Marta N, Martins Luís C, Sá-Correia Isabel
iBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisbon, Portugal.
Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisbon, Portugal.
J Fungi (Basel). 2021 Jan 27;7(2):90. doi: 10.3390/jof7020090.
Methanol is a promising feedstock for metabolically competent yeast strains-based biorefineries. However, methanol toxicity can limit the productivity of these bioprocesses. Therefore, the identification of genes whose expression is required for maximum methanol tolerance is important for mechanistic insights and rational genomic manipulation to obtain more robust methylotrophic yeast strains. The present chemogenomic analysis was performed with this objective based on the screening of the Euroscarf haploid deletion mutant collection to search for susceptibility phenotypes in YPD medium supplemented with 8% (/) methanol, at 35 °C, compared with an equivalent ethanol concentration (5.5% (/)). Around 400 methanol tolerance determinants were identified, 81 showing a marked phenotype. The clustering of the identified tolerance genes indicates an enrichment of functional categories in the methanol dataset not enriched in the ethanol dataset, such as chromatin remodeling, DNA repair and fatty acid biosynthesis. Several genes involved in DNA repair (eight genes, identified as specific for methanol toxicity, were previously reported as tolerance determinants for formaldehyde, a methanol detoxification pathway intermediate. This study provides new valuable information on genes and potential regulatory networks involved in overcoming methanol toxicity. This knowledge is an important starting point for the improvement of methanol tolerance in yeasts capable of catabolizing and copying with methanol concentrations present in promising bioeconomy feedstocks, including industrial residues.
甲醇是基于代谢能力强的酵母菌株的生物精炼厂一种很有前景的原料。然而，甲醇毒性会限制这些生物过程的生产力。因此，鉴定那些其表达对于最大程度的甲醇耐受性是必需的基因，对于获得更强大的甲基营养型酵母菌株的机理洞察和合理的基因组操作很重要。基于对欧洲酵母保藏中心单倍体缺失突变体文库的筛选，为了寻找在补充了8%（体积分数）甲醇的YPD培养基中，于35℃下与同等乙醇浓度（5.5%（体积分数））相比的敏感性表型，进行了本次化学基因组学分析。鉴定出了大约400个甲醇耐受性决定因素，其中81个表现出明显的表型。所鉴定的耐受性基因的聚类表明，甲醇数据集中功能类别的富集在乙醇数据集中未富集，如染色质重塑、DNA修复和脂肪酸生物合成。几个参与DNA修复的基因（八个基因，被鉴定为对甲醇毒性具有特异性，先前被报道为甲醛（一种甲醇解毒途径中间体）的耐受性决定因素）。本研究提供了关于参与克服甲醇毒性的基因和潜在调控网络的新的有价值信息。这些知识是提高能够分解代谢并耐受有前景的生物经济原料（包括工业废渣）中存在的甲醇浓度的酵母甲醇耐受性的重要起点。
