The cell wall of Bacillus subtilis was shown to lie externally to the Gram-positive staining area of the cell. Conversion of these bacteria to the Gram-negative state, whether natural or induced, did not necessarily result in a decrease in cell size. When a decrease occurred it was correlated with the disappearance of an ‘ectoplasm’ staining area and with the inability of the residual cell substance to be converted to the Gram-positive state with magnesium ribonueleate.
Cell autolysis proceeded as follows. First the cell lost magnesium ribonucleate and was therefore Gram-negative, the ectoplasm and cell wall staining areas were retained, and the cell could be reconverted to the Gram-positive state by exposure to magnesium ribonueleate. The size of the cell was normal. Next, the ectoplasm and cell wall staining areas disappeared. This was correlated with an inability to be re-converted to the Gram-positive state and with a smaller size. Finally, cell autolysis was completed and the cell disappeared.
Gram-negative species were shown to possess an ectoplasm staining area which differed from that of normal Gram-positive cells since it could not be made to stain Gram-positive by exposure to magnesium ribonucleate. The ectoplasm staining area of Gram-positive cells was shown not to be in itself the reason for Gram-positive staining. However, the presence of this area correlated with the cells ability to be reconverted to the Gram-positive state by magnesium ribonucleate, and thus it is probably important in the Gram reaction.
EisenbergP.1909; Studien zur Ektoplasmatheorie. II. Teil. Ueber das Ekto- plasma und seine Veranderungen im infizierten Tier. Zbl. Bakt 1. Abt. Orig. 49:465
GutsteinM.1924; Das Ektoplasma der Bakterien. I. Ueber eine allgemeine Methode zur Darstellung des Ektoplasmas der Grampositiven Bakterien. Zbl. Bakt 1. Abt. Orig. 93:393
GutsteinM.1925; Das Ektoplasma der Bakterien. II. Mitt. Ueber farberische Verscheidenheiten zwischen Grampositiven und Gramnegativen Bakterien. Ein Beitrag zur Theorie der Gramschen Farbung. Zbl. Bakt 1. Abt. Orig. 94:145
JonesA. S.,
StaceyM.,
WebbM.1949; Studies on the autolytic systems of Gram-positive micro-organisms. I. The lytic system of staphylococci. Biochim, Biophys. Acta 3:383