Table 1.

Kinetic parameters for [14C]choline uptakea in estuarine waters and filtrate cultures from Mobile Bay, Ala.

Sample and dateSalinity (ppt)Temp (°C)Kt + Sn (nM)Vmax (nM · h−1)Turnover time of Sn (h)
Whole water
 14 Nov 199512151.70.53.2
 26 June 199615314.13.31.3
Filtrate culturesb
 5 Dec 199617222.93.30.9
 12 Sept 199724261.71.90.9
  • a Uptake rates were determined by using 5 to 20 min incubations depending on the experiment.

  • b 24-h-old filtrate cultures (<0.7 μm) composed mainly of bacteria were used for these experiments.