Nadir ağır azot çiftleri mikrobiyal azot kaybını görünür kılıyor

Microbes help regulate water quality by converting biologically usable nitrogen compounds into nitrogen gas, yet scientists have struggled to measure how much gas they produce. Water already contains abundant nitrogen gas absorbed from the atmosphere, which can conceal the microbial contribution. Researchers led by UCLA found a natural fingerprint in the way nitrogen isotopes pair inside molecules. Atmospheric nitrogen contains pairs of two heavy nitrogen-15 atoms more often than chance would predict, whereas microbes assemble nitrogen atoms almost randomly. When microbial gas mixes with atmospheric gas, the excess of heavy pairs declines. Using a high-resolution mass spectrometer, the team detected this subtle signal in groundwater, lakes, coastal basins and deep-sea sediments. The method could reveal whether microbes remove nitrate pollution before it reaches rivers or coasts, improve assessments of fertilizer and wastewater impacts, and help scientists calculate regional and global nitrogen budgets more accurately.