ISSN:
1432-072X
Keywords:
Acidic compartments
;
Chlorella vulgaris
;
Chloroquine
;
Compartmentation
;
Inorganic phosphate
;
Intracellular pH
;
in vivo nuclear magnetic resonance
;
Neutral red
;
Unicellular algae
;
Vacuoles
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Acidic inorganic phosphate (Pi) pool (pH around 6) was detected besides the cytoplasmic pool in intact cells of Chlorella vulgaris 11h by 31P-in vivo nuclear magnetic resonance (NMR) spectroscopy. It was characterized as acidic compartments (vacuoles) in combination with the cytochemical technique; staining the cells with neutral red and chloroquine which are known as basic reagents specifically accumulated in acidic compartments. Under various conditions, the results obtained with the cytochemical methods were well correlated with those obtained from in vivo NMR spectra; the vacuoles were well developed in the cells at the stationary growth phase where the acidic Pi signal was detected. In contrast, cells at the logarithmic phase in which no acidic Pi signal was detected contained only smaller vesicles that accumulated these basic reagents. No acidic compartment was detected by both cytochemical technique and 31P-NMR spectroscopy when the cells were treated with NH4OH. The vacuolar pH was lowered by the anaerobic treatment of the cells in the presence of glucose, while it was not affected by the external pH during the preincubation ranging from 3 to 10. Possible vacuolar functions in unicellular algae especially with respect to intracellular pH regulation are discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00425353
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