AUTOLYSIS OF 57 STRAINS OF DAIRY PROPIONIBACTERIA

Dairy propionibacteria contribute to proteolysis and lipolysis of the curd in Swiss-type cheese technology by the release of intracellular e nzymes. Autolysis of 57 strains of dairy propionibacteria has been com pared in 0.1 mol/l potassium phosphate buffer (pH 6.2) and the rate an d extent of autolysis appeared to be strain-dependent. Two distinct cl usters were observed: cluster A containing 8 strains highly prone to l ysis and cluster B containing all the other strains. Genomic fingerpri nting of the 8 strains constituting cluster A revealed 7 distinct prof iles. Growth of 4 of these 7 strains showed a spontaneous autolysis in the growth medium just after the maximal growth, without any stationa ry phase.