Bacteria as a Protein Source: What’s the Potential?

Bacteria as a Protein Source: What’s the Potential?

Building on earlier work with single-cell proteins (SCPs) and fungal fermentation, this phase of the InnoProtein project looks at how bacterial proteins can be efficiently produced, refined, and prepared for real-world use.

What makes bacterial protein a particularly promising alternative isn’t just how efficiently it can be grown, but what it can be grown from. InnoProtein partners Tecnalia and Biotrend identified bacterial strains capable of growing on methanol, a simple, renewable carbon source. 

The bacteria in question, known as methylotrophic bacteria, are well-suited to feeding on methanol, breaking it down and using it as fuel to grow and multiply. The result is a biomass-rich in protein, produced without the need for conventional agricultural inputs such as crops or land. 

This circular production model makes bacterial protein a promising candidate for more sustainable, resource-efficient ingredients1.


Optimizing Growth

While the bacteria used in this work can convert methanol into protein-rich biomass, getting consistent results requires careful management of several variables. For example, too much methanol can actually inhibit bacterial growth rather than support it, so feeding it into the fermentation process at the right rate is critical2. 

Additionally, nutrients and oxygen need to be kept at levels that support stable fermentation34. Maintaining a steady supply of these essentials sustains bacterial activity and leads to more reliable protein output.

These refinements matter especially as production scales beyond the lab. The result of this careful process is a biomass with a strong nutritional profile and protein content that is competitive with conventional sources, reinforcing the case for bacterial SCPs as a viable alternative5.


From Biomass to Ingredient

As previous InnoProtein work on protein extraction has shown, producing biomass is only part of the challenge. The next step is turning it into something usable. 

Extraction is what bridges the gap between growing protein-rich bacteria and actually putting them to work as an ingredient. In practice, this involves breaking open the bacterial cells to release the proteins inside, then separating and concentrating them into a usable form. 

The approach taken here directly affects how much protein is recovered, as well as its purity and functionality67. Downstream steps like precipitation and filtration refine the product further, helping tailor it for specific food and feed applications.


Connecting the Process


Taken together, these advances underscore the value of treating protein production as a connected system rather than a series of isolated steps. As with earlier stages of InnoProtein, progress here is cumulative, and each step, from cultivation to processing, builds toward the same goal: scalable, high-quality protein ingredients.

References

  1. Gundupalli MP, Ansari S, da Costa JPV, Qiu Fb, Anderson J, Luckert M, Bressler DC. 
    (2024) Bacterial single cell protein (BSCP): A sustainable protein source from 
    methylobacterium species. Trends in Food Science & Technology, 147:104426. 
    https://doi.org/10.1016/j.tifs.2024.104426 ↩︎
  2. Hӓggstrӧm MH, Dostálek M. (1981) Growth of Methylomonas methanolica: Factors 
    influencing growth yield. European Journal of Applied Microbiology and Biotechnology, 
    12:107-112. https://doi.org/10.1007/BF01970043 ↩︎
  3. Sarwar A, Lee EY. (2023) Methanol-based biomanufacturing of fuels and chemicals 
    using native and synthetic methylotrophs. Synthetic and Systems Biotechnology, 8:396–
    415. https://doi.org/10.1016/j.synbio.2023.06.001 ↩︎
  4. Schrader J, Schilling M, Holtmann D, Sell D, Filho MV, Marx A, Vorholt JA. (2008)
    Methanol-based industrial biotechnology: current status and future perspectives of 
    methylotrophic bacteria. Trends in Biotechnology, 27(2):107-115. 
    https://doi:10.1016/j.tibtech.2008.10.009 ↩︎
  5. Gundupalli MP, Ansari S, da Costa JPV, Qiu F, Anderson J, Luckert M, Bressler DC. (2024) Bacterial single cell protein (BSCP): A sustainable protein source from methylobacterium species. Trends in Food Science & Technology, 147:104426. https://doi.org/10.1016/j.tifs.2024.104426 ↩︎
  6. Hildebrand, G., Poojary, M. M., O’Donnell, C., Lund, M. N., Garcia-Vaquero, M., & Tiwari, B. K. (2020). Ultrasound-assisted processing of Chlorella vulgaris for enhanced protein extraction. Journal of Applied Phycology, 32(3), 1709–1718. https://doi.org/10.1007/s10811-020-02105-4 ↩︎
  7. Sela, K., Budhijanto, W., & Budiman, A. (2021). Protein extraction from spirulina platensis by using ultrasound assisted extraction: Effect of solvent types and extraction time. Key Engineering Materials, 872 KEM, 33–37. https://doi.org/10.4028/www.scientific.net/KEM.872.33 ↩︎