Engineered microbe offers promising high-quality protein from methanol

Facing urgent protein scarcity, sustainable alternatives are critical, with microbial protein derived from methanol being recognized as a promising solution. Derived from renewable sources like biogas, methanol surpasses traditional sugars, providing high-reduction power for efficient production.

Researchers have identified Methylophilus sp. HN238, a bacterium capable of efficiently converting methanol into high-quality protein. Optimization in shake flasks boosted protein yield by an impressive 387.3%. Scaling up to a 5 L bioreactor produced biomass with a high protein content of 57.3%. The protein meets WHO standards for quality, containing all 18 amino acids with essential amino acids making up 44.1% of the composition.

Crucially, the study revealed how high methanol concentrations affect the microbe. Transcriptome analysis showed these conditions cause an imbalance: increased activity of the methanol-digesting enzyme, but decreased activity of formaldehyde dehydrogenase and cytochrome c. This metabolic disruption leads to toxic formaldehyde buildup, oxidative stress, reduced energy production, and ultimately inhibits growth.

The work entitled “Screening and fermentation optimization of Methylophilus sp. HN238 for efficient microbial protein production using methanol” was published on Systems Microbiology and Biomanufacturing (published on June 11, 2025).