The Effects of Nutrient Deficiencies and Analogs on the Cell and Nuclear Volume of Tetrahymena pyriformis*

Abstract

SYNOPSIS. Cell volume and nuclear volume measurements were made on Tetrahymena pyriformis strain E cells that had been either (a) suspended in a medium deficient in some nutrient or (b) suspended in a medium containing a metabolic inhibitor. Media deficient in a nucleotide or containing nucleotide analogs did not significantly inhibit growth. However, cell volume changes were observed for cells grown on nucleotidedeficient medium. Amino acid deficient medium inhibited growth completely and both cell and nuclear volume decreased significantly. The minimal volumes attained were 2/3 of the control volume. Media containing amino acid analogs did not completely inhibit growth nor did appreciable volume changes occur. Both cell and nuclear volumes were closely intercorrelated throughout the results.

Cultivation of the Peritrich Telotrochidium henneguyi in Axenic and Non‐Axenic Media*

“…The nucleotide mix in T-3 demands analysis: when it was omitted the medium allowed survival, but the telas were Jh to smaller than robust organisms in T-broth or in T-3 containing the nucleotide mix. These results seem to support the view of Summers (31,32) that cell volume is affected in ciliates grown in nucleotide-deficient media.…”

“…The osmotic-shock method utilizing distilled water(4) was moderately successful in that it induced excystment of 50 to 70% oi the populations in 24 to 48 hr. Mechanical agitation induced excystmcnt of 90 to IMl% of the populations within [30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45] min: telas (encysted in a culture tube) were agitated by holding the tube in a I'ortex Jr. mixer (Scientific Industries, Inc.. Springfield. Mass.)…”