Exploring the Fermentation Potential of <i>Kluyveromyces marxianus</i> NS127 for Single-Cell Protein Production

<i>Kluyveromyces marxianus</i> is a food-grade yeast known for its diverse beneficial traits, making it an attractive candidate for both food and biotechnology applications. This study explores the potential of <i>Kluyveromyces marxianus</i> as a promising alternative protein source for single-cell protein (SCP) production. Various <i>Kluyveromyces</i> strains were isolated and screened from traditional fermented dairy products, with <i>Kluyveromyces marxianus</i> NS127 identified as the most promising strain due to its superior growth characteristics, high SCP yield, and environmental tolerance. Notably, <i>Kluyveromyces marxianus</i> NS127 demonstrated significant substrate conversion capacity with a biomass yield of 0.63 g biomass/g molasses, achieving a dry biomass concentration of 66.64 g/L and a protein yield of 28.37 g/L. The protein extracted from the dry biomass exhibited excellent solubility (62.55%) and emulsification properties (13.15 m²/g) under neutral conditions, alongside high foaming stability (93.70–99.20%) across a broad pH range (3–11). These results underscore the potential of <i>Kluyveromyces marxianus</i> NS127 as a viable alternative protein source and provide a solid theoretical foundation for its industrial application.