Changes in Oxygen Uptake Rates, Enzyme Activities, Cytochrome Amounts and Adenine Nucleotide Pool Levels during Growth of Acanthamoeba castellanii in Batch Culture

Abstract

Summary: Complex changes in the activities of cytochrome c oxidase, succinate dehydrogenase, catalase, alkaline phosphatase and acid hydrolases, and in the levels of cytochromes were observed during the growth cycle of Acanthamoeba castellanii in a proteose peptone/glucose/yeast extract medium. A transition occurred at the mid-exponential phase of growth without any change in the growth rate. A second transition corresponded with the cessation of growth; the specific activities of cytochrome c oxidase, succinate dehydrogenase and alkaline phosphatase declined during the stationary phase of growth whereas the specific activities of catalase and the acid hydrolases increased. Glucose was not utilized during the first 30 h of growth and the respiration rate was low, AMP levels were high and some AMP appeared extracellularly. After 30 h, values for the adenylate charge rose from less than 0.1 to more than 0.7, although ATP levels per cell did not vary. When cells were grown in conditioned medium (obtained by removing cells from a 48 h culture) the characteristics of a normal culture observed before 30 h were lost.