Antagonistic interactions between propionic acid bacteria and non-starter lactic acid bacteria

Abstract

5ummary -L rhamnosus JCL 1211 and L casei JCL 1227 isolated from hard cheese facultatively heterofermentative microflora were shown to negatively interfere with the growth of P freudenreichii in hard Swiss-type cheese. As the observed inhibition cou Id not be reproduced in batch cultures, the metabolism of inhibitory species was studied in cheese and in culture. Citrate appears to be the principal energy source for growth of facultatively heterofermentative microflora which metabolizes it to acetate, formate and carbonate. Small amounts of diacetyl are also produced during citrate fermentation. Diacetyl, acetate and formate can participate in the inhibitory ettect observed.