CASTDan:Abstract12
Kostov, Y., Tolosa, L., Harms P., Rao, G. (2002) Noninvasive Measurement of Dissolved Oxygen in Shake Flasks. Biotechnology and Bioengineering. 80, 594–597
Abstract
Shake flasks are ubiquitous in cell culture and
fermentation. However, conventional devices for measuring
oxygen concentrations are impractical in these
systems. Thus, there is no definitive information on the
oxygen supply of growing cells. Here we report the noninvasive,
nonintrusive monitoring of dissolved oxygen
(DO) in shake flasks using a low-cost optical sensor. The
oxygen-sensitive element is a thin, luminescent patch affixed
to the inside bottom of the flask. The sensitivity and
accuracy of this device is maximal up to 60% DO, within
the range that is critical to cell culture applications. By
measuring actual oxygen levels every 1 or 5 min
throughout the course of yeast and E. coli fermentations,
we found that a modest increase in shaker speed and a
decrease in culture volume slowed the onset of oxygen
limitation and reduced its duration. This is the first time
that in situ oxygen limitation is reported in shake flasks.
The same data is unattainable with a Clark type electrode
because the presence of the intrusive probe itself
changes the actual conditions. Available fiber optic oxygen
sensors require cumbersome external connections
and recalibration when autoclaved. © 2002 Wiley Periodicals,
Inc. Biotechnol Bioeng 80: 594–597, 2002.
