On the nature of the granules of the genus spirillum

Summary Chemical analyses of centrifugal fractions of cell-free extracts of three spirilla and Sacch. cerevisiae showed that the granular inclusions accumulated by these organisms do not contain significant amounts (if any) of polyphosphates. Further, no trichloroacetic acid extractable-barium precipitable polyphosphates could be isolated from the spirilla. Thus, the granules of spirilla, heretofore called volutin, are not identifiable with polyphosphates.The phase opaque bodies present in members of this genus are composed primarily of poly--hydroxybutyrate. It is recommended that the term volutin no longer be used to describe granules showing a metachromatic reaction.