Studies of the comparative physiology of the genus Dunaliella (Chlorophyta, Volvocales)

Abstract

Growth curves, yields and doubling-times of six Dunaliella isolates were measured at 26 and 36°C in batch-type cultures growing at NaCl concentrations from 0·5 to 4 m. Cultures had been pre-adapted to temperature and NaCl concentration and were inoculated from cultures that were themselves in the logarithmic phase of growth. Even so, in many cases the initial growth rate was slow. The doubling-time varied in one of three ways; either it increased with outside NaCl concentration, or it remained constant, or (most often) it had a minimum value at some intermediate NaCl concentration and rose at both extremes.