Sucrose-Induced Transcriptomic Response in Ogataea polymorpha TBRC 4839 Reveals its Potential for Recombinant Protein Production.

The thermotolerant yeast Ogataea polymorpha TBRC 4839 is a promising host for heterologous protein expression using sucrose and molasses as low-cost carbon sources, making it suitable for industrial applications. This study analyzed the genome and transcriptome of O. polymorpha under sucrose-induced conditions. The nuclear genome of strain TBRC 4839 measures 8.9 Mbp with a GC content of 47.87%, consistent with other Ogataea species. The genome encodes 5184 protein-coding genes, comparable to related strains. Additionally, the mitochondrial genome spans 49.4 Kbp and has a low GC content of approximately 20%. Transcriptomic analysis revealed that sucrose induction triggers a metabolic shift characterized by increased carbohydrate metabolism and decreased amino acid biosynthesis, stress signaling, and cell division, enabling efficient energy utilization in sucrose-rich environments. Among the identified genes with up-regulated expression, five were notable: FUN_000066 (hypothetical protein), FUN_001144 (maltose permease), FUN_001145 (maltase), FUN_002060 (mitochondrial NAD-dependent malic enzyme), and FUN_002263 (hypothetical protein). The promoter efficiency was evaluated by expressing the fungal xylanase gene under sucrose-inducing conditions using these promoters. The maltase (MAL) promoter exhibited the highest xylanase production efficiency, outperforming other promoters. Furthermore, the MAL promoter proved effective for xylanase production when molasses was used as the carbon source. These findings underscore the potential of O. polymorpha TBRC 4839 and the MAL promoter for industrial protein production.