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Cell Size, Macromolecular Composition, and O 2 Consumption During Agitated Cultivation of Naegleria gruberi *
Author(s) -
WEIK R. R.,
JOHN D. T.
Publication year - 1977
Publication title -
the journal of protozoology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.067
H-Index - 77
eISSN - 1550-7408
pISSN - 0022-3921
DOI - 10.1111/j.1550-7408.1977.tb05306.x
Subject(s) - growth rate , biology , naegleria , bacterial growth , composition (language) , carbohydrate , zoology , food science , saturation (graph theory) , chemistry , biochemistry , microbiology and biotechnology , protozoa , bacteria , linguistics , philosophy , geometry , mathematics , genetics , combinatorics
SYNOPSIS. Cell size, macromolecular composition, carbohydrate utilization patterns, and O 2 concentrations were measured throughout the growth stages of Naegleria gruberi in agitated cultures in a complex medium. Biphasic logarithmic growth occurred during the initial 83 hr of growth and the mean generation time was 7.0 hr and 19 hr during initial and secondary log growth stages, respectively. The maximum yield was 5 × 10* amebaeJml. The pH rose rapidly (1 pH unit) during the secondary log growth phase (52‐83 hr) and continued into the stationary growth phase (83‐120 hr). Dry weight, total protein, carbohydrate, and RNA per ameba increased just before the secondary log growth phase. RNA increased 31% to 35% per ameba at the end of each phase of log growth. DNA increased ∼ 2‐fold throughout the different growth phases. Average cell size increased 90% during biphasic log growth then decreased during stationary phase. O 2 tension decreased from 100% to 18% of saturation during the biphasic growth phase, then increased during stationary growth to near 100% saturation. Glucose and total carbohydrate assays showed little utilization of those substrates throughout the growth stages. Naegleria gruberi presumably has a predominantly aerobic metabolism, also its metabolism may change during the different growth phases.