The methylotrophic yeast Pichia pastoris (syn. Komagataella phaffii) is a successful host widely used in recombinant protein production. The widespread use of a methanol-regulated alcohol oxidase 1 (AOX1) promoter for recombinant protein production has directed studies particularly about methanol metabolism in this yeast. Although there is comprehensive knowledge about methanol metabolism, there are other mechanisms in P. pastoris that have not been investigated yet, such as ethanol metabolism. The gene responsible for the consumption of ethanol ADH2 (XM_002491337, known as ADH3) was identified and characterized in our previous study. In this study, the ADH genes (XM_002489969, XM_002491163, XM_002493969) in P. pastoris genome were investigated to determine their roles in ethanol production by gene disruption analysis. We report that the ADH900 (XM_002491163) is the main gene responsible for ethanol production in P. pastoris. The ADH2 gene, previously identified as the only gene responsible for ethanol consumption, also plays a minor role in ethanol production in the absence of the ADH900 gene. The investigation of the carbon source regulation mechanism has also revealed that the ADH2 gene exhibit similar expression behaviours with ADH900 on glucose, glycerol, and methanol, however, it is strongly induced by ethanol.

中文翻译：

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毕赤酵母乙醇代谢中主要ADH基因的鉴定。

甲基营养酵母巴斯德毕赤酵母（S. Komagataella phaffii）是成功用于重组蛋白生产的宿主。甲醇调节的醇氧化酶1（AOX1）启动子在重组蛋白生产中的广泛应用，尤其是针对该酵母中甲醇代谢的研究。尽管对甲醇代谢有全面的了解，但巴斯德毕赤酵母中还有其他机制尚未研究，例如乙醇代谢。在我们先前的研究中，鉴定并表征了负责消耗乙醇ADH2的基因（XM_002491337，称为ADH3）。在这项研究中，研究了巴斯德毕赤酵母基因组中的ADH基因（XM_002489969，XM_002491163，XM_002493969），以通过基因破坏分析确定其在乙醇生产中的作用。我们报告说ADH900（XM_002491163）是负责在巴斯德毕赤酵母中生产乙醇的主要基因。ADH2基因以前被认为是造成乙醇消耗的唯一基因，在缺少ADH900基因的情况下，在乙醇生产中也起着较小的作用。对碳源调节机制的研究还表明，ADH2基因在葡萄糖，甘油和甲醇上表现出与ADH900类似的表达行为，但是，乙醇强烈诱导了该基因的表达。