Numerous studies have investigated the effect of CO, and 0, concentrations on Pseudomonas growth and have observed that CO, was an effective growth inhibitor at certain concentrations
and temperatures (Clark and Burki, 1972; Wells. 1974; Gill and Tan, 1979; Enfors and Molin,
1980; Moir et al., 1993; Willocx et al., 1993). All of these reports have shown that as temperature fell, the inhibitory power of COz increased.