The cell walls of Pseudomonas aeruginosa. General composition.

1. Cell walls of Pseudomonas aeruginosa were prepared and analysed. 2. Separate preparations were found to be reproducible, e.g. the phosphorus contents of all batches lay in the range 2.0-2.1%. 3. Ninhydrin-positive compounds in hydrolysates accounted for 43-46% of the cell wall and 79-87% of the nitrogen of the cell wall. Examination of the results for individual ninhydrin-positive compounds showed that 5-15% of the cell wall was murein and about 30% protein. 4. Trypsin treatment of crude cell-wall preparations preferentially liberated arginine, lysine and leucine, but it was not clear whether these arose from cell-wall or cytoplasmic proteins.