Screening methods for the proteolytic breakdown of gluten by lactic acid bacteria and enzyme preparations.

摘要

Proteolytic activity of lactic acid bacteria derived from starter cultures used in sourdough or meat fermentation was tested on gluten as a substrate. Activities of commercial enzyme preparations, derived from bacterial or fungal sources, were alsoevaluated. Proteolytic breakdown of gluten in an agar medium by either bacterial culture or enzymes was evident by a clear zone around wells after staining with Coomassie blue. The increase in TCA-soluble material due to gluten breakdown was measuredspectrophotometrically. A third test evaluated the release of free amino acids due to exoproteolytic activity. The agar based test showed positive results for the commercial enzyme preparations and one Micrococcus strain. All sourdough strains were positive in the enzyme test, whereas some starters from the meat fermentation process were not able to break down gluten under test conditions. Variations in the release of free amino acid indicated differences in the enzyme systems of the lactic acid bacteria tested.