Role of KLa on growth and enzyme production by Acetobacter tropicalis
The volumetric oxygen transfer coefficient (KLa) is one
of the most important scale up factors in fermentations.
KLa value affected the growth rate and enzyme activity in
A. tropicalis for the production of dextransucrase. In the
present study, the growth of A. tropicalis increased with
increase in KLa from 0.11 to 0.28 min-1 and thereafter
decreased suddenly with further increase in KLa (Figure
4). Maximum biomass (1.41 mg/ml) was obtained at
0.28 min-1 KLa. Similar pattern was observed in case of
dextransurase production by A. tropicalis. Initially enzyme
activity increased with increase in KLa upto a limit and
then decreased (Figure 4). Maximum dextransucrase
activity (15.77 U/ml) was obtained at 0.28 min-1 KLa.
This exactly coincides with the profile obtained for the
growth of A.tropicalis. So, it could be concluded from the
above data that higher oxygen transfer rate adversely
affect the growth of A. tropicalis which in turn result in
less dextransucrase production. Maximum production
of proteases (15.28 UP/ml) by Staphylococcus aureus
mutant RC128 was obtained when the bioreactor was