title: Axenic mass cultivation of the free-living soil amoeba, Acanthamoeba castellanii in a laboratory fermentor.
abstract: Axenic mass cultivation of Acanthamoeba castellanii in laboratory fermentors (141) yielded after 20 days approximately 3 g cells (wet weight). After a short lag phase amoebal cell numbers increased exponentially to a maximum of 3.5 x 10(5) cells per ml until cell death occurred after 20 days. Optical density and protein concentrations revealed identical patterns. During amoebal growth only 12-19% of the initially added glucose (100 mM) as sole carbon source was used. Large amounts of ammonia (1 g in 10.51 culture volume) were excreted into the medium which subsequently raised the pH from 6.6 to 7.7, and from 6.6 to 6.8 in 2 and 20 mM buffered media, respectively. Growth inhibition and cell death could not be explained by a depletion of glucose or oxygen limitations during growth. The production of ammonia had a growth inhibitory effect, however, the sudden termination of the exponential growth phase and cell death could not be explained by the toxic influence of ammonia only.
authors.affiliation: Department of Microbiology, Faculty of Science, University of Nijmegen, The Netherlands.
authors.forename: P H
authors.initials: PH
authors.lastname: Weekers
authors.forename: J P
authors.initials: JP
authors.lastname: Wijen
authors.forename: B P
authors.initials: BP
authors.lastname: Lomans
authors.forename: G D
authors.initials: GD
authors.lastname: Vogels
mesh_terms: D000048:Acanthamoeba / Q000254:growth & development* / Q000378:metabolism; D000641:Ammonia / Q000378:metabolism / Q000494:pharmacology; D000818:Animals; D005285:Fermentation; D005947:Glucose / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D010100:Oxygen / Q000378:metabolism; D012987:Soil
chemical_list: D012987:Soil; D000641:Ammonia; D005947:Glucose; D010100:Oxygen