ISSN:
1420-9071
Keywords:
Oxygen gradients
;
Ca-alginate
;
pO2-microelectrodes
;
immobilized microorganisms
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary Oxygen concentrations were measured in single Ca-alginate beads using polarographic microneedle electrodes. To obtain reliable results the effects of mechanical pressure on the electrode as well as the influence of free Ca2+-ions had to be compensated. No oxygen gradients were detectable in cell-free alginate beads, whereas in beads with entrapped cells ofEnterobacter cloacae steep oxygen gradients were observed. The steepness of these gradients depended on the bacterial growth in the gel. At the end of the logarithmic phase of growth the maximum depth of oxygen penetration into a bead of about 3 mm in diameter was in the range of 150 μm; i.e. nearly 70% of the volume of the alginate beads was free of oxygen.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01950156
