From genetic constraints to process hurdles: A review of Kluyveromyces marxianus for efficient bio-manufacturing and bio-processing in food industry

Kluyveromyces marxianus ( K . marxianus ) has emerged as a prominent microbial platform owing to its exceptional intrinsic properties, demonstrating significant potential for biomanufacturing. A literature search with the keyword ‘ Kluyveromyces marxianus ’ in title in the PubMed database indicated that the yeast has been developed as a microbial cell factory for lignocellulosic biomass valorization, heterologous protein production, flavor and fragrance molecule synthesis during the past 10 years. However, the most recent review of K . marxianus application in food industry was 5 years ago. The relatively slow progression is partially due to the paucity of molecular tools and the lagging advancements in process optimization strategies. This review summarizes the physiological characteristics of K. marxianus and its potential industrial applications. Addressing the requirements of industrial-scale production, key limiting factors in high-cell-density fermentation,including carbon source utilization efficiency, dissolved oxygen regulation, and inhibition by metabolic byproducts were analyzed. An integrated approach combining dynamic feeding, metabolic pathway engineering, and fermentation parameter optimization was proposed. Considering the previous reviews, the present work updated the application of K. marxianus in the food industry, including the production of enzymes, sugars, aromatic compounds, single-cell protein, and transformation of food waste, as well as the treatment of wastewater during food processing, and aims to make a comprehensive discussion. Through the systematic construction of the research paradigm from molecular constraints to process hurdles, the work may help the transition of K . marxianus for efficient manufacturing and processing in the food industry. • The specific advantages of K. marxianus are presented • The high-density fermentation of K. marxianus and optimization strategies are summarized • Biological toolkits for constructing K. marxianus cell factories are proposed • Emerging applications of K. marxianus in food are summarized