Therefore, maintaining one single environmental
condition throughout the fermentation process may not be optimal
for maximal carotenoid production. pH is one of the most important
environmental parameters affecting cell growth and product formation.
According to literature, the pH optimum for the cell growth
and -carotene production is not the same. Hence the fermentation
process is carried out at suboptimal conditions if a constant
pH stat approach is adapted [20,24,25].