Numerical taxonomy of psychrotrophic lactic acid bacteria from prepacked meat and meat products

Ninety-four strains of lactic acid bateria isolated from refrigerated, prepacked meat and meat products were together with 59 reference strains of Brochothrix, Lactobacillus, Leuconostoc, Pediococcus and Streptococcus phenotypically classfied, using 96 unit characters. Data were examined using Simple Matching (S_SM) or Jaccard coefficient (S_J), and unweighted pair group algorithm with arithmetic averages. Twenty-three clusters with two or more members were defined at the 84% S_SM-similarity level which corresponded to the S_J-similarity level of 61%. Based on S_SM, most field strains were included in nine clusters, and with three unsignificant exceptions these contained no reference strains. The field clusters were designated Carnobacterium piscicola (cluster 1; 5% of field isolates), Carnobacterium divergens(cluster 2; 9% of field isolates), Leuconostoc (cluster 9; 18% of field isolates) and Lactobacillus (cluster 4, 10, 11, 12, 13 and 14; together 60% of field isolates). The Lactobacillus clusters had many features in common with cluster II of Shaw & Harding (1984). Phenotypical characteristics of major clusters are given. The S_SM and S_J based classifications basically coincided for the field strains; the exception was cluster 4 which now were split in two parts. Fourteen clusters were made up of mainly reference strains (S_SM). Most of them included more than one type strain on species level; exceptions were Brochothrix thermosphacta (cluster 3), Lactobacillus salivarius (cluster 17) and Leuconostoc mesenteroides (cluster 18). Several rearrangements were seen amongst the clusters of the reference strains when S_J, instead of S_SM, was used for clustering.