Ratios of carbon, nitrogen and phosphorus in Pseudomonas fluorescens as a model for bacterial element ratios and nutrient regeneration

Bactena play a sign~ficant role in the nutnent dynamics of plankton~c systems, yet the11 nutrient demands are poorly known Heie, we charactenze the element latios of a common freshwater bactenum relative to growth rate and nutrient availability P s e ~~d o m o n a s fluorescens was grown in chemostats at dilution rates of 0 03 0 06, and 0 09 h ' Phosphorus (P) was supplied at approximately 5 ~.IM and nitrogen (N) was supphed at varylng concentlatlons to establish resource molar-N P ratios (SNP) ranglng between 5 1 and 117 1 Carbon was supplied In excess Chemostats were sampled at steady state the element composition of cells (Q) was determined and element ratlos (C& ,