Methylococcus capsulatus

Technical Data

Type of microorganism	Bacterium
Microorganism name	Methylococcus capsulatus
Temperature range	40-45°C (Stegantseva et al., 2021) 37°C-47°C (Harwood & Pirt, 1972)
pH range	pH 6.5 (Stegantseva et al., 2021)
Carbon and nitrogen source	Methane, ammonia (Stegantseva et al., 2021)
Growth rate (µ)	0.103/hour on methane in lab scale in bubble column reactor (Henard et al., 2018) 0.140/hour in optimal conditions in lab scale in batch fermentor (Harwood & Pirt, 1972)
Companies (product)	Calystra (Feedkind) UniBio (Uniprotein) StringBio
Wild-type or GMO	Wild-type
Feedstock case studies (suitable substrates)	Natural or unconventional natural methane gas (Stegantseva et al., 2021)
% SCP (w/w percentage of protein in dried biomass)	87-88% (Stegantseva et al., 2021) 70% for Uniprotein (Ritala et al., 2017)
cell biomass dry weight (CDW) = biomass yield? (g/L or g/g?) (weight of biomass/total weight or volume)	85% (w/w) on methane on lab scale in bubble column reactor (Henard et al., 2018) 2.82% (w/v) on methane on lab scale in biofermentor (Jang et al., 2023)
Protein content in final product	75.14% for Feedkind fish feed (Xu et al., 2021)
Protein titer (g/L or g/g?) grams of protein / total weight or volume	0.28% (w/v) (own calculation for production of Uniprotein based on Ritala et al., 2017))
Productivity (g/Lh)	4 for the production of Uniprotein on industrial scale (Ritala et al., 2017)
Protein yield on C-source (% w/w)	NA
Scale	Done on industrial scale (Uniprotein, Feedkind)
Downstream purification processing complexity	Flocculation step to reduce RNA content, followed by centrifugation (Stegantseva et al., 2021)
Nucleic acid content	9% (Lieven et al., 2018) 2.5-2.9% at the end of the processing procedure (Stegantseva et al., 2021)
Techno-functional and/or nutritional properties (e.g. meat-like texture, amino acid profile, digestibility)	High protein content (all amino acids present). Almost all amino acids present in higher amounts than standard fish feed. High digestibility in fish. (Xu et al., 2021)
Target application (Food, feed, other)	Used in feed (pigs, fish), but also as pet food and is being explored for human consumption
Advantages	Rich in proteins, all amino acids present. Use in fish feed enhaces the growth (Xu et al., 2021).
Challenges (Key limitations, risk factors)	No regulatory framework for use in food yet. Substrate (methane as a gas) is hard to work with.
Regulatory status in Europe	Allowed for use in feed Europe. Not allowed in food
Regulatory status in other parts of the world	Allowed for feed and pet food market in the US No information found for Canada and Singapore
Extra/remark	Extra bacterial consortium nedded to support the growth in industrial SCP setting (Bothe et al., 2002)
Publications/references	Stegantseva, Y., Newman, L. M., Kwan, W., Hwang, J., Giver, L. J., & Schiff-Deb, C. (2021, April). WO2021071966A1 - Methods for culturing methanotrophic bacteria and isolating proteins from bacterial biomass - Google Patents. https://patents.google.com/patent/WO2021071966A1/en Henard, C. A., Franklin, T. G., Youhenna, B., But, S., Alexander, D., Kalyuzhnaya, M. G., & Guarnieri, M. T. (2018). Biogas Biocatalysis: Methanotrophic Bacterial Cultivation, Metabolite Profiling, and Bioconversion to Lactic Acid. Frontiers in Microbiology, 9. https://doi.org/10.3389/fmicb.2018.02610 Bothe, H., Jensen, K. M., A, M., J, L., C, J., Bothe, H., & L, J. (2002). Heterotrophic bacteria growing in association with Methylococcus capsulatus (Bath) in a single cell protein production process. Applied Microbiology and Biotechnology, 59(1), 33–39. https://doi.org/10.1007/s00253-002-0964-1 Harwood, J. H., & Pirt, S. J. (1972). Quantitative Aspects of Growth of the Methane Oxidizing Bacterium Methylococcus capsulatus on Methane in Shake Flask and Continuous Chemostat Culture. Journal of Applied Bacteriology, 35(4), 597–607. https://doi.org/10.1111/j.1365-2672.1972.tb03741.x Xu, B., Liu, Y., Chen, K., Wang, L., Sagada, G., Tegomo, A. F., Yang, Y., Sun, Y., Zheng, L., Ullah, S., & Shao, Q. (2021). Evaluation of Methanotroph (Methylococcus capsulatus, Bath) Bacteria Meal (FeedKind®) as an Alternative Protein Source for Juvenile Black Sea Bream, Acanthopagrus schlegelii. Frontiers in Marine Science, 8. https://doi.org/10.3389/fmars.2021.778301 Jang, N., Jeong, J., Ko, M., Song, D., Emelianov, G., Kim, S. K., Rha, E., Kwon, K. K., Kim, H., Lee, D., Lee, H., & Lee, S. (2023). High Cell-Density Cultivation of Methylococcus capsulatus Bath for Efficient Methane-Derived Mevalonate Production. Journal of Agricultural and Food Chemistry, 71(12), 4924–4931. https://doi.org/10.1021/acs.jafc.3c00286 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 Lieven, C., Petersen, L. a. H., Jørgensen, S. B., Gernaey, K. V., Herrgard, M. J., & Sonnenschein, N. (2018). A Genome-Scale Metabolic Model for Methylococcus capsulatus (Bath) Suggests Reduced Efficiency Electron Transfer to the Particulate Methane Monooxygenase. Frontiers in Microbiology, 9. https://doi.org/10.3389/fmicb.2018.02947