S. Fujii et Ja. Hellebust, GROWTH AND OSMOREGULATION OF BOEKELOVIA-HOOGLANDII IN RELATION TO SALINITY, Canadian journal of botany, 72(6), 1994, pp. 823-828
The growth and osmoregulation of Boekelovia hooglandii Nicolai et Baas
Becking (Chrysophyceae) was investigated as a function of salinity. T
his chromophyte microflagellate was found to be euryhaline and also to
require sodium for growth. The optimum sodium chloride concentration
for growth was 0.2-0.4 M, and growth was severely inhibited in media w
ith sodium chloride concentrations above 1 M. Using gas chromatography
- mass spectroscopy analysis of cell extracts, it was established tha
t the alga contains D-mannitol, myo-inositol, as well as the inositol
derivative, cyclohexanetetrol. The content of cyclohexanetetrol and ma
nnitol increased with increased salinity, while the content of inosito
l remained almost constant. Potassium and magnesium were the major int
racellular cations. However, the content of cations and amino acids sh
owed only minor increases with salinity over a wide salinity range. Th
e contents of cyclohexanetetrol and mannitol increased rapidly when ce
lls were subjected to hypertonic shocks. It was concluded that B. hoog
landii utilizes cyclohexanetetrol and mannitol as osmoregulatory subst
ances.