Brzozowski, Bartosz, and Małgorzata Lewandowska. 2014. “Prolyl Endopeptidase - Optimization of Medium and Culture Conditions for Enhanced Production by Lactobacillus Acidophilus”. Electronic Journal of Biotechnology 17 (5). Valparaíso, Chile. https://preprints.pucv.cl/index.php/ejbiotechnology/article/view/2014.07.003.