title: Differential increase in activity of acid phosphatase induced by phosphate starvation in Tetrahymena.
abstract: We have studied the effects of phosphate starvation on the levels and distributions of activities of acid phosphatase and beta-hexosaminidase in cultures of Tetrahymena thermophila. The cells were grown in synthetic nutrient medium and refed every day with fresh medium. After 4 days of growth in the complete medium, the cultures were divided into two portions. One received complete medium and the other phosphate-free, but otherwise complete, medium. Population densities and activities of acid phosphatase and beta-hexosaminidase in cells plus medium and in cell-free samples were determined in aliquots removed every day before medium replacement. In cultures having complete medium the enzyme levels remained fairly constant; in the phosphate-starved cultures both total and extracellular activities of acid phosphatase increased sixfold. beta-Hexosaminidase levels remained essentially unaltered in both cases. These results indicate that phosphate starvation can induce differential increase in acid phosphatase activity in cultures of Tetrahymena. Somewhat less than 50% of the total activities of both enzymes are found in the cell-free extracellular fluid at any time.
authors.affiliation: Department of Anatomy and Cytology, Odense University, Denmark.
authors.forename: L
authors.initials: L
authors.lastname: Rasmussen
authors.forename: M
authors.initials: M
authors.lastname: Florin-Christensen
authors.forename: J
authors.initials: J
authors.lastname: Florin-Christensen
authors.forename: T
authors.initials: T
authors.lastname: Kiy
authors.forename: A
authors.initials: A
authors.lastname: Tiedtke
mesh_terms: D000135:Acid Phosphatase / Q000096:biosynthesis*; D000818:Animals; D003470:Culture Media; D004790:Enzyme Induction; D010710:Phosphates / Q000172:deficiency; D016808:Tetrahymena thermophila / Q000201:enzymology*; D001619:beta-N-Acetylhexosaminidases / Q000096:biosynthesis
chemical_list: D003470:Culture Media; D010710:Phosphates; D000135:Acid Phosphatase; D001619:beta-N-Acetylhexosaminidases