vol·u·tin 
(vŏlyə-tĭn, və-ltn)
(vŏlyə-tĭn, və-ltn)n.
A granular substance that stains easily with a basic dye and is often rich in phosphorus, found in the cytoplasm of various bacterial and fungal cells.
[German, from New Latin (Spirillum) volūtāns, species of bacterium in which it was first found, from Latin volūtāns, present participle of volūtāre, to roll around, frequentative of volvere, to roll; see wel-2 in the Appendix of Indo-European roots.]