Studies on the biochemistry and fine structure of silica shell formation in diatoms: Changes in concentration of nucleoside triphosphates during synchronized division of Cylindrotheca fusiformis Reimann and Lewin

Exponential cultures of the diatom Cylindrotheca fusiformis subjected to a single dark period of 24 hr, followed by re-illumination at a high light intensity, undergo a synchronized cycle of growth, which can be divided into three periods: (1) increase in carbon mass; (2) silicon uptake, nuclear division, cytokinesis, and wall formation; (3) cell separation. Marked changes in the concentration of nucleoside triphosphates were observed during transitions in illumination and during the synchronized growth cycle. A decrease in concentration of NTP/μg carbon was observed during the period of silicon uptake, whereas a subsequent increase in NTP/μg carbon occurred once silicon uptake from the medium ceased. These changes, differing from those reported for several non-siliceous organisms, suggest that in C. fusiformis NTP participates in the silicon metabolism of cell wall formation.