Biological Valorization of Methane and N2-derived Ammonia via Methanotrophic Bacteria for Gut-Beneficial Nutrients

Rational metabolic engineering strategies were employed to endow the methanotrophic bacterium with an enhanced ability to utilize ammonia. An optimized fed-batch fermentation process was further developed to minimize hydroxylamine-induced toxicity and efficiently produce nutritional cell mass containing essential amino acids and polysaccharides. Oral administration of nutritional cell mass maintains gut microbiota homeostasis and promotes the excretion of beneficial metabolites, thereby protecting the intestinal microenvironment.