“…Using this 15 N-NMR approach, nitrogen metabolism was characterized in live microorganisms such as the fungus Neurospora crassa [873,874], C. glutamicum, a bacterium used for industrial production of amino acids [875,876], Pseudomonas [758], or cyanobacteria [877], and even once in mammalian cells [878]. From the late 1980's, most 15 N-NMR studies on living organisms were concerned with nitrogen assimilation by plants, focusing on symbiotic bacteria [879] or fungi [880][881][882], algae [883], spruce buds [884] or cell cultures [885], maize root [886][887][888], duckweed [889], invasive weed [890,891] and even carrot cell suspensions [892,893]. 15 Ndetected solid-state NMR spectra were also carried out on lyophilized soybean cotyledon or leaves to determine nitrogen fluxes from ammonium, nitrate, N 2 , asparagine, glutamine, allantoin or methionine [894][895][896][897][898][899].…”