%0 Journal Article %A Gotham, Ivan J. %A Rhee, G-Yull %T Effects of Nitrate and Phosphate Limitation on Cyclostat Growth of Two Freshwater Diatoms %D 1982 %J Microbiology, %V 128 %N 1 %P 199-205 %@ 1465-2080 %R https://doi.org/10.1099/00221287-128-1-199 %I Microbiology Society, %X The effects of N and P limitation on cell division and on cellular contents of limiting and non-limiting nutrients were examined in cyclostat cultures of the freshwater diatoms Asterionella formosa and Fragilaria crotonensis. Nutrient-limited cell cycles of both species were readily entrained by a 14 h/10 h light/dark cycle. In F. crotonensis, the maxima relative to the onset of the light phase of the photocycle occurred at approximately − 1 to +1 h for cell division, +11 to 13 h for cell N, and +21 to 23 h for cell P. In A. formosa the maxima occurred at approximately +3 to 10 h for cell division and +2 to 4 h for cell N and cell P. Changes in culture dilution rate (integrated growth) and in the type of nutrient limiting growth did not significantly alter these times for either species. The cell-number oscillations can be explained by a simple exponential function for the instantaneous population growth rate, which occurs after a single modal transition time τ, which is characteristic for each species. The consistency of phase relations between N and P limitations and culture dilution rates suggests that the temporal organization for events within the cell cycle of each organism is independent of the nutrient-limited status of the cell populations. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-128-1-199