Engineering Methylotrophic Yeasts as Cell Factories for Chemical Production Using Methanol as a Feedstock

Methanol, a sustainable and abundant one-carbon (C1) feedstock, has emerged as a promising raw material for green biomanufacturing, offering a pathway to carbon neutrality. Natural methylotrophic yeasts such as Pichia pastoris (syn. Komagataella phaffii) and Ogataea polymorpha are increasingly recognized as attractive hosts due to their high methanol utilization rates and established roles in industrial protein and chemical production. However, their large-scale application faces critical challenges, such as low methanol assimilation efficiency, carbon loss, and methanol toxicity. This review highlights recent progress in the engineering of natural methanol cell factories, with a focus on strategies to overcome these bottlenecks. Topics include engineering the methanol assimilation and dissimilation pathways, adaptive laboratory evolution, metabolic compartmentalization, and C1/Cn cosubstrate utilization. By addressing these challenges and exploring innovative approaches, natural methylotrophic yeasts can be further developed as efficient platforms for methanol-based biomanufacturing, thus accelerating progress toward sustainable and carbon-neutral industrial processes.