show that increasing the phosphate buffer concentration increased the GABA production.
Maximal GABA production was found with 80 mM phosphate buffer.
GABA was produced at 6.36 mM (7.71 mg/g of bran).
However, when the concentration increased to more than 80 mM,
the GABA production decreased slightly.
This was possibly due to an increase in the ionic strength in the reaction system.
A higher ionic strength might reduce the activity of the enzyme