A numerical taxonomic study of lactic acid bacteria isolated from irradiated pork and chicken packaged under various gas atmospheres

Abstract

Ninety-four Gram-positive, catalase-negative bacteria, isolated from pork and chicken that had been packed in modified atmospheres and irradiated to 1.75 and 2.5 kGy respectively, were studied. The majority of the strains were Lactobacillus saké. Numerical taxonomy, with the group average clustering strategy, revealed the existence of six clusters at the 85% similarity level. The largest, Cluster 1, contained 78 (83%) of the test strains along with three Lact. sak'e strains. Cluster 2 contained three test strains and the type strains of Carnobacterium piscicola and Carn. divergens. Cluster 3 contained two chicken strains and Lact. curvatus. Cluster 4 contained a pork strain and Leuconostoc dextranicum. Clusters 5 and 6 contained four pork and two chicken strains respectively and no type strains. Four test strains remained unclustered as did the other reference strains included in the study.