Natarajan et al. (1995b) measured the specific activity of PHA
degrading enzyme b-hydroxybutyrate dehydrogenase and found
decreased activity of the enzyme in Rhizobium DDSS 69 at 6% NaCl
concentration. Therefore, it is possible that at 3.5 and 6.5 g/l NaCl
concentrations, the PHA degradation was slower due to the
decreased activity of b-hydroxybutyrate dehydrogenase and hence
significant PHA degradation did start until after 36–38 h. But at
higher salt concentrations of 9, 12 and 15 g/l NaCl, significant