Activation-independent capture of free fatty acids at the bacterial cell envelope by BrtB.

BrtB enables cyanobacteria to incorporate exogenous free fatty acids directly onto glycolipids without prior activation, occurring at or near the cell envelope in vivo.

• Why it matters: Understanding how bacteria utilize environmental fatty acids is crucial for insights into membrane dynamics and metabolic flexibility, yet the mechanisms bypassing activation are poorly known.
• What they did: Researchers studied the cyanobacterium Synechocystis salina LEGE 06099 and found that supplemented FFAs are converted into esterified forms within minutes by BrtB, with minimal gene expression changes, indicating a pre-existing pathway.
• The result: This activation-independent FFA incorporation expands knowledge of bacterial lipid metabolism and suggests glycolipids may transiently sequester FAs in response to environmental availability.