Adding a new dimension to the global carbon cycle

Glycolic acid is a direct by-product of photosynthesis and one of the most important compounds in the carbon cycle of the oceans. Though marine bacteria convert some of its carbon back into carbon dioxide, the exact metabolic pathways remained largely unknown. We rediscovered a long forgotten pathway, the BHA cycle. This cycle was overlooked so far, but actually represents the major pathway for glycolic acid degradation in ubiquitous marine Proteobacteria. Its detailed and multidisciplinary elucidation enables reassessment of the global carbon dioxide balance.