Kluyveromyces marxianus

Technical Data

Type of microorganism	Yeast
Microorganism name	Kluyveromyces marxianus
Temperature range	30°C (Dong et al., 2025) 40°C (Yadav et al., 2013)
pH range	pH 4.5-5.5 (Dong et al., 2025) pH 3.5 (Yadav et al., 2013)
Carbon and nitrogen source	Molasses, corn steep liqour & NH4Cl (Dong et al., 2025) Lactose, urea (Koukoumaki et al., 2024)
Growth rate (µ)	0.20-0.44/hour (Dong et al., 2025) 0.2/hour (P. J. Anderson et al., 1988)
Companies (product)	Provesteen in the past? (Ritala et al., 2017) No comapnies found that use it for boimass fermentation today.
Wild-type or GMO	Wild-type
Feedstock case studies (suitable substrates)	Cheese whey (Yadav et al., 2013) Orange pulp, molasses, spent grain from brewery, pulp of potato (Amara & El-Baky, 2023)
% SCP (w/w percentage of protein in dried biomass)	42.60% on molasses on lab scale in bioreactor (Dong et al., 2025) 37% on cheese whey on lab scale in bioreactor (Koukoumaki et al., 2024)
cell biomass dry weight (CDW) = biomass yield? (g/L or g/g?) (weight of biomass/total weight or volume)	6.664% (w/v) on molasses on lab scale in bioreactor (Dong et al., 2025) 19% (w/w) on lab scale in bioreactor with cheese whey as substrate (Yadav et al., 2013)
Protein content in final product	No product available
Protein titer (g/L or g/g?) grams of protein / total weight or volume	2.837% (w/v) on molasses on lab scale in bioreactor (Dong et al., 2025) 0.135% (w/v) on cheese whey on lab scale in bioreactor (Koukoumaki et al., 2024)
Productivity (g/Lh)	4.81 for continuous fermentation on lab scale in bioreactor with fructose as substrate (Kim et al., 1998) 0.26 for continuous fermentation with cell recycle on lab scale in bioreactor with cheese whey as substrate (Yadav et al., 2013)
Protein yield on C-source (% w/w)	63% (w/w) on molasses on lab scale in bioreactor (Dong et al., 2025)
Scale	Only done on lab scale
Downstream purification processing complexity	No info about downstream proces, most likely similar processing as other yeast products.
Nucleic acid content	4.82% (Paul et al., 2002)
Techno-functional and/or nutritional properties (e.g. meat-like texture, amino acid profile, digestibility)	High protein content (all amino acids present). Low levels of sulphur containing amino acids (Koukoumaki et al., 2024) High amount of folic acid (Paul et al., 2002)
Target application (Food, feed, other)	Shows potential for use in fish feed. (Øverland et al., 2013)
Advantages	Rich in proteins, all amino acids present. High vitamin and mineral content.
Challenges (Key limitations, risk factors)	Not all amino acids present at high enough level for FAO reccomendations (methionine and cysteine not). No meat-like texture. Not approved as biomass fermentation product.
Regulatory status in Europe	No approval for biomass fermenation product, but a live strain as probiotic is approved (Turval)
Regulatory status in other parts of the world	No approval for biomass fermenation product, but a live strain as probiotic is approved in the US & Canada (Turval)
Extra/remark
Publications/references	Dong, L., Wu, Y., Li, M., Zhang, C., Cao, J., Ledesma-Amaro, R., Zhao, W., & Kang, D. (2025). Exploring the Fermentation Potential of Kluyveromyces marxianus NS127 for Single-Cell Protein Production. Fermentation, 11(2), 70. https://doi.org/10.3390/fermentation11020070 Yadav, J. S. S., Bezawada, J., Elharche, S., Yan, S., Tyagi, R. D., & Surampalli, R. Y. (2013). Simultaneous single-cell protein production and COD removal with characterization of residual protein and intermediate metabolites during whey fermentation by K. marxianus. Bioprocess and Biosystems Engineering, 37(6), 1017–1029. https://doi.org/10.1007/s00449-013-1072-6 Koukoumaki, D. I., Papanikolaou, S., Ioannou, Z., Mourtzinos, I., & Sarris, D. (2024). Single-Cell Protein and Ethanol Production of a Newly Isolated Kluyveromyces marxianus Strain through Cheese Whey Valorization. Foods, 13(12), 1892. https://doi.org/10.3390/foods13121892 Anderson, P. J., McNeil, K. E., & Watson, K. (1988). Thermotolerant single cell protein production byKluyveromyces marxianus var.marxianus. Journal of Industrial Microbiology, 3(1), 9–14. https://doi.org/10.1007/bf01569436 Kim, J. K., Tak, K., & Moon, J. (1998). A continuous fermentation of Kluyveromyces fragilis for the production of a highly nutritious protein diet. Aquacultural Engineering, 18(1), 41–49. https://doi.org/10.1016/s0144-8609(98)00021-1 Amara, A. A., & El-Baky, N. A. (2023). Fungi as a Source of Edible Proteins and Animal Feed. Journal of Fungi, 9(1), 73. https://doi.org/10.3390/jof9010073 Ritala, A., Häkkinen, S. T., Toivari, M., & Wiebe, M. G. (2017). Single Cell Protein—State-of-the-Art, Industrial Landscape and Patents 2001–2016. Frontiers in Microbiology, 8. https://doi.org/10.3389/fmicb.2017.02009 Paul, D., Mukhopadhyay, R., Chatterjee, B. P., & Guha, A. K. (2002). Nutritional Profile of Food Yeast Kluyveromyces fragilis Biomass Grown on Whey. Applied Biochemistry and Biotechnology, 97(3), 209–218. https://doi.org/10.1385/abab:97:3:209 Øverland, M., Karlsson, A., Mydland, L. T., Romarheim, O. H., & Skrede, A. (2013). Evaluation of Candida utilis, Kluyveromyces marxianus and Saccharomyces cerevisiae yeasts as protein sources in diets for Atlantic salmon (Salmo salar). Aquaculture, 402–403, 1–7. https://doi.org/10.1016/j.aquaculture.2013.03.016