Methylotrophic Bacteria: Small Organisms Providing Proteins

Global protein demands are at an all-time high. However, using only animal-based proteins such as meat is not sufficient to meet this demand. In the quest for developing alternative proteins for animal-based foods, researchers are experimenting with algae, fungi, insects, and bacteria. Which bacteria should be used in this process? The InnoProtein project is on a mission to discover the best bacteria for protein purposes and make the process as efficient as possible.

Using Bacteria?

Scientists have long been looking at bacteria to produce single-cell proteins. Already in the 1970s, the industry experimented with bacteria to use as feedstock. However, due to high prices and the low cost of animal-based proteins, these experiments were stowed away for some time. In recent years, this interest has been on the rise once again. Various bacterial species have already been used to create single-cell proteins, such as Lactobacillus acidophilus (which feeds on stick water and glucose) and Purple non-sulfur bacteria (which feed on food waste)¹. So why choose methylotrophic bacteria?

When experimenting in the 70s, researchers used methylotrophic bacteria to produce single-cell proteins, which is the type of bacteria InnoProtein is focusing on as well. These types of bacteria are microorganisms that are capable of growing on methanol, which is a carbon source that can be produced sustainably from renewable sources [1]. Additionally, using bacteria to substitute other protein sources is not seasonally dependent, and it does not use arable land or a lot of water [2]. This makes them low-cost and low-impact [1, 2].

Protein Content

Methylotrophic bacteria are very efficient in converting the carbons described above into protein-rich biomass. The biomass that they produce can even contain up to 80% protein! This makes methylotrophic bacteria one of the most protein-dense microbial sources available for single-cell protein production. For comparison, while the methylotrophic bacteria contain 60-80% protein content, the protein content of meat is only about 45%, that of soybeans is about 35%, and the protein content of milk is around 35% [3].

Why is this important? Their high protein content makes methylotrophic bacteria a very efficient producer of protein, as they produce more protein per unit compared to both animal- and plant-based alternatives [3]. This also means that you need less biomass to achieve the same protein levels, which reduces overall production costs and resource use.

Amino Acids

Proteins are not just about quantity. While it is great that bacteria are very effective protein providers, scientists are also concerned about the right amino acid profiles in those proteins. With 20 different variants, amino acids are the building blocks used for making proteins. Some of these amino acids can be made by your own body, while the other amino acids are obtained through your diet [4].

Some Hiccoughs Along the Way

Based on the information above alone, methylotrophic bacteria seem like a perfect solution to manufacture single-cell proteins. However, there are some significant drawbacks that need to be taken into account. First of all, the methods to extract protein-rich biomass from bacteria is still an expensive process, especially compared to traditional protein alternatives [1]. Additionally, since the processes used are still fairly new and expensive, this brings several scale-up challenges, particularly if proteins made from bacteria are to be produced for human consumption on a large scale [1]. Furthermore, the InnoProtein partners defined other challenges as follows: there is a high demand for oxygen during the fermentation process of bacteria, and the production of single-cell proteins from bacteria might result in high nucleic acid content, which is not preferable for human consumption [5]. 

A lot of work is still needed to fully explore and understand the potential of transforming bacteria into single-cell proteins. The InnoProtein project will continue testing two different strains of methylotrophic bacteria. Stay tuned for the results!

References

[1] M. P. Gundupalli, S. Ansari, J. P. V. da Costa, F. Qiu, J. Anderson, M. Luckers en D. C. Bressler, „Bacterial single cell protein (BSCP): A sustainable protein source from methylobacterium species,” Trends in Food Science & Technology, vol. 147, 2024. 

[2] InnoProtein, „Bacteria: Sustainable Protein Production with Methylotrophic Bacteria,” InnoProtein, [Online]. Available: https://innoprotein.eu/infographics/bacteria/. [Geopend 7 April 2026].

[3] Y. Ghasemi, S. Rasoul-Amini en M. H. Horowvat, „Algae for the production of SCP,” in Bioprosess Sciences and Technology, New York, Huppage, 2011, pp. 163-184.

[4] S. A. Bates, „Amino acids,” National Human Genome Research Institute, 7 April 2026. [Online]. Available: https://www.genome.gov/genetics-glossary/Amino-Acids. [Geopend 7 April 2026].

[5] I. Farinha, „Development of cultivation processes for strains from the Methylomonas, Methylophillus and Methylobacterium,” 2024.