title: Axenic Paramecium caudatum. I. Mass culture and structure.
abstract: To establish and grow Paramecium caudatum in mass axenic culture the culture medium of Soldo, Godoy & van Wagtendonk was modified by substituting phosphatidylethanolamine (PE) for TEM-4T and by a 10-fold increase in folic acid. Population densities of 4000 to 6000 cells/ml and a generation time of 20-26 h are regularly obtained. Optimal growth is obtained with PE-stigmasterol ratios between 40:1 to 400:1. Cells from 1-day-old axenic cultures have many lipid bodies aggregated in clumps (which disappear in 2 to 3 days) as well as foci of rough endoplasmic reticulum bordered by dictyosomes. The latter suggests a very active metabolism. Crystalline sheets found in both food vacuoles and lysosomes presumably play a role in digestion. Axenically grown cells also have abundant Golgi bodies (dictyosomes) and by late log phase become filled with lysosomes.
mesh_terms: D000818:Animals; D003470:Culture Media; D009940:Organoids / Q000648:ultrastructure; D010247:Paramecium / Q000254:growth & development* / Q000378:metabolism / Q000648:ultrastructure; D010714:Phosphatidylethanolamines / Q000378:metabolism; D013265:Stigmasterol / Q000378:metabolism
chemical_list: D003470:Culture Media; D010714:Phosphatidylethanolamines; D013265:Stigmasterol