Production of Aminopeptidase from Skim Milk Whey Permeate Medium by Lactobacillus casei ssp. casei

¹ Research and Development, Ault Foods Limited, 75A Bathurst Street, London, ON, Canada N6B 1N8
² Faculté des Sciences de L'agriculture et de L'alimentation, Université Laval, Québec, QC, Canada G1K 7P4

Extracellular and intracellular aminopeptidases were produced from Lactobacillus casei ssp. casei grown in skim milk whey permeate, but those grown in MRS medium produced intracellular enzyme only. Extracellular enzyme was produced by intact cells rather than by cell lysis. The enzyme was highly unstable during storage at –20°C or –80°C or upon cell breakage. Aminopeptidase production from cells, regardless of their growth medium, was predominantly associated with growth. Cells released aminopeptidase on extraction with Triton X-100, phosphate buffer, or lysozyme in decreasing order of activity.

Key Words: Lactobacillus casei ssp. casei • skim milk whey permeate medium • MRS medium • aminopeptidase production

Submitted on February 13, 1995
Accepted on October 23, 1995