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

ABSTRACT

Ninety-four strains of lactic acid bacteria isolated from refrigerated, prepacked meat and meat products were together with 59 reference strains of Brochothrix, Lactobacillus, Leuconostoc, Pediococcus and Streptococcus phenotypically classified, using 96 unit characters. Data were examined using Simple Matching (SSM) or Jaccard coefficient (SJ), and unweighted pair group algorithm with arithmetic averages. Twenty-three clusters with two or more members were defined at the 84% SSM-similarity level which corresponded to the SJ-similarity level of 61%. Based on SSM, 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 SSM and SJ 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 (SSM). 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 SJ, instead of SSM, was used for clustering.