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Variation in the Growth Medium During the Culture Cycle of Tetrahymena: With Special Reference to Ammonia (NH 3 ), Ammonium (NH 4 +), and pH 1
Author(s) -
LARSEN JØRGEN,
SVENSMARK BO,
NILSSON JYTTE R.
Publication year - 1988
Publication title -
the journal of protozoology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.067
H-Index - 77
eISSN - 1550-7408
pISSN - 0022-3921
DOI - 10.1111/j.1550-7408.1988.tb04148.x
Subject(s) - tetrahymena pyriformis , tetrahymena , ammonia , ammonium , growth medium , cell growth , stationary phase , biology , cell cycle , ciliate , growth rate , biophysics , biochemistry , chemistry , cell , chromatography , ecology , bacteria , genetics , organic chemistry , geometry , mathematics
The ciliate Tetrahymena pyriformis was grown in a peptone medium without added glucose. The interrelationship between increasing cell density and pH of the growth medium was studied from mid‐log to the stationary phase, i.e. from 50,000 to 1,000,000 cells/ml, by continuous registration of the pH of the growth medium. The present findings correlate with the known physiological, biochemical, and structural changes occurring in Tetrahymena as it passes through the culture cycle. The ammonia production of the cells and the buffer capacity of the growth medium were determined throughout the growth cycle. The results revealed that the ammonia excreted by the cells can explain the increase in pH of the medium from 6.8 to about 8.3 normally seen during the culture cycle. Moreover, neither the increased pH nor the raised level of ammonia were found to be the responsible factor for cessation of cell proliferation in the stationary growth phase although these factors may affect cell proliferation in concentrations well beyond the range found in normal cultures.