Background: Lactic acid bacteria are able to reduce the immunoreactivity of proteins of cereal grains duringwheat
dough fermentation ormay be a source of proteolytic preparations added during bread making. The key enzyme
in prolamin degradation is prolyl endopeptidase. This studywas aimed at optimizing the composition of a culture
medium and culture conditions that would enhance the synthesis of intracellular prolyl endopeptidase (PEP) by
Lactobacillus acidophilus
5e2.
Results: The application of Plackett–Burman screening plans enabled demonstrating that the concentration of a
nitrogen source in the culture and the initial pH value of the culture medium were significant for PEP
synthesis. Further optimization conducted with the method of central composite designs (CCD) confirmed
both the linear and square impact of nitrogen concentration and initial pH value of the culture medium on PEP
production. In turn, the response surface method (RSM) allowed determining the optimal nitrogen
concentration and pH value at 26.88 g/l and pH 4.85, respectively.
Conclusions: Validation of the resultant model enabled over 3-fold increase in the quantity of the synthesized
enzyme.
