[Proteolytic activities of Ps. fluorescens in milk: determination with azocasein in comparison with HPA].
Proteolytic activity of psychotrophie bacteria in milk can be measured in a practical and comparatively sensitive manner using Azocasein as a substrate. The necessary parameters were exemplarily developed and demonstrated with a typical, strongly proteolytic strain of Pseudomonas fluorescens (No. 112). Comparison of the improved Azocasein method with a modified version of the HPA method of Cliffe and Law--they had proposed it for predicting the stability of UHT milk--showed nearly the same sensitivity with six test strains of Pseudomonas fluorescens. The first significant detection of proteolytic activity could be made approximately at the same time except with one strain of the biotype II (miscellaneous strains). It is discussed, whether the demonstrated methods can be judged (by the bacterial counts of detection) as sufficiently sensitive for to prediction of term spoilage during storage of UHT products.
D000818:Animals; D002364:Caseins / Q000378:metabolism*; D002417:Cattle; D003094:Collagen / Q000378:metabolism*; D010450:Endopeptidases / Q000378:metabolism*; D005519:Food Preservation; D006863:Hydrogen-Ion Concentration; D008892:Milk / Q000378:metabolism*; D011551:Pseudomonas fluorescens / Q000201:enzymology*; D013379:Substrate Specificity; D013696:Temperature
D002364:Caseins; C026018:azocasein; D003094:Collagen; D010450:Endopeptidases
Proteolytische Aktivitäten von Ps. fluorescens in Milch: Bestimmung mit Azocasein und vergleichsweise mit HPA.