Characterization of JEN family carboxylate transporters from the acid‐tolerant yeast Pichia kudriavzevii and their applications in succinic acid production

作者：Yongyan Xi, Tao Zhan, Hongtao Xu, Jing Chen, Changhao Bi, Feiyu Fan, Xueli Zhang · 发表于：Microbial Biotechnology · 年份：2021 · DOI：10.1111/1751-7915.13781 · 被引用次数：46 · 研究领域：Fungal and yeast genetics research、Microbial Metabolic Engineering and Bioproduction、Fermentation and Sensory Analysis

The unconventional yeast Pichia kudriavzevii is renowned for its ability to survive at low pH and has been exploited for the industrial production of various organic acids, especially succinic acid (SA). However, P. kudriavzevii can also utilize the di- and tricarboxylate intermediates of the Krebs cycle as the sole carbon sources for cell growth, which may adversely affect the extracellular accumulation of SA. Because the carboxylic acid transport machinery of P. kudriavzevii remains poorly understood, here, we focused on studying its SA transportation process from the perspective of mining and characterization of dicarboxylate transporters in a newly isolated acid-tolerant P. kudriavzevii strain CY902. Through genome sequencing and transcriptome analysis, two JEN family carboxylate transporters (PkJEN2-1 and PkJEN2-2) were found to be involved in SA transport. Substrate specificity analysis revealed that both PkJEN proteins are active dicarboxylate transporters, that can effectively import succinate, fumarate and L-malate into the cell. In addition, PkJEN2-1 can transport α-ketoglutarate, while PkJEN2-2 cannot. Since PkJEN2-1 shows higher transcript abundance than PkJEN2-2, its role in dicarboxylate transport is more important than PkJEN2-2. In addition, PKJEN2-2 is also responsible for the uptake of citrate. To our best knowledge, this is the first study to show that a JEN2 subfamily transporter is involved in tricarboxylate transport in yeast. A combination of model-based...