Chemical composition of the spore sheath of Streptomyces griseus.

The fibrillar sheath surrounding spores of Streptomyces griseus was separated from spores and partially purified by differential centrifugation. The reaction of isolated sheath material to various solvents and enzymes was monitored by electron microscopy. Fibrilar elements (rodlets) were apparently resistant to most solvents and enzymes used; only acetone induced any change in their appearance. Analysis of sheath material showed that its composition differed considerably from that of spore walls, having a low content of nitrogen (1.7% w/w), amino sugars (0.067% w/w) and carbohydrate (0.036% w/w). It was suggested that the sheath may be at least partially inorganic in nature.