Microbial Metabolism of Amino Acids—Biologically Induced Removal of Glycine and the Resulting Fingerprint as a Potential Biosignature

The identification of reliable biomarkers, such as amino acids, is key for the search extraterrestrial life. A large number microorganisms metabolize, synthesize, take up and excrete acids part acid metabolism during aerobic and/or anaerobic respiration or in fermentation. In this work, we investigated whether microbial could leave a secondary biosignature indicating biological activity environment around cells. observed fingerprints would reflect physiological capabilities specific community under investigation. metabolic processing an mixture by two distinct communities collected from Islinger Mühlbach (ISM) Sippenauer Moor (SM), Germany was examined. contained L-alanine, β-alanine, L-aspartic acid, DL-proline, L-leucine, L-valine, glycine, L-phenylalanine L-isoleucine. parallel, spiked medium without used control to determine abiotic changes over time. Liquid chromatography mass spectrometry (LC-MS) track When comparing samples that did not show significant concentrations time, found glycine almost completely depleted both less than 3% after first weeks- This results indicates preferential use simple these communities. Although degradation can be caused processes, its depletion consistent with presence We most other varied between communities, suggesting complex dynamics no clear universal pattern might signature However, marked increases cellular synthesis release into extracellular (e.g., alanine), were considered activity. conclude, substantial anomalous enhancements some against expected background concentration may agnostic processes.