Nyo. Muyima et Te. Cloete, GROWTH AND PHOSPHATE-UPTAKE OF IMMOBILIZED ACINETOBACTER CELLS SUSPENDED IN ACTIVATED-SLUDGE MIXED LIQUOR, Water research, 29(11), 1995, pp. 2461-2466
Immobilization of Acinetobacter cells can provide a method which could
possibly be used to explain the mechanism of biological phosphorus re
moval from AS systems since this may allow the study of pure cultures
in their natural habitat. Pure cultures of Acinetobacter johnsonii and
Acinetobacter calcoaceticus cells were therefore immobilized within a
lginate beads (3% and 3.5% alginate) to assess their behaviour and par
ticularly, their survival, leakage, growth and phosphate uptake abilit
ies. Both species survived immobilization conditions, however, the eff
ects on viability, leakage rate, growth and phosphate uptake were depe
ndent upon the alginate concentration and the strain. Notwithstanding
leakage, cell densities within alginate beads over 24 h were higher th
an initial densities due to growth. The growth rate of A. calcoaceticu
s immobilized cells was twice that of free cells, while A. johnsonii s
howed similar growth rates between immobilized and free cells. Non gro
wing immobilized cells showed higher phosphate uptake ability than gro
wing cells. After 24 h, A. calcoaceticus immobilized cells removed mor
e phosphate per cell than A. johnsonii cells while both species showed
higher phosphate uptake ability when immobilized in 3% alginate than
in 3.5% alginate.