Comprehensive Lipidomic Analysis of Streptomyces by NPLC-HRMS Reveals a Previously Unknown Phospholipid Class

Studies on lipids in Streptomyces bacteria are limited and primarily rely on thin-layer chromatography (TLC) and off-line mass spectrometry. In this article, we present an in-depth analysis of Streptomyces lipids, performed using normal-phase liquid chromatography coupled with high-resolution mass spectrometry (NPLC-HRMS), applied to various Streptomyces strains in recent collaborations. All identified lipid classes detected in the extracts are described. Numerous mass spectra are provided, offering a detailed view of the distribution of molecular species and their structural characteristics. Above all, HRMS analyses allowed us to elucidate the structure of a new class of phospholipids that had never been described before. This new phospholipid, called PIPA, was shown to result from the condensation of phosphatidylinositol (PI) and phosphatidic acid (PA) and is detected at a specific time in the Streptomyces cell cycle.