1. In growing cells of Mycobacterium phlei, phospholipids showed an appreciable turnover. 2. Among the components of phospholipids, cardiolipin had the highest turnover rate. 3. Phosphatidyl-inositol oligomannosides and phosphatidyl ethanolamine showed relatively low turnovers compared with that of cardiolipin. 4. Phosphatidic acid was also a metabolic precursor of phospholipids even in the cells of M. phlei.
