U. Lyhs et al., Characterisation of lactic acid bacteria from spoiled, vacuum-packaged, cold-smoked rainbow trout using ribotyping, INT J F MIC, 52(1-2), 1999, pp. 77-84
A total of 405 lactic acid bacteria (LAB) isolated from spoiled, vacuum-pac
kaged, salted, sodium nitrite- or potassium nitrate-treated, cold-smoked ra
inbow trout stored at 4 degrees C or 8 degrees C were characterised and ide
ntified using a molecular method. The isolates were initially classified ac
cording to their restriction endonuclease profiles using HindIII and EcoRI
restriction endonucleases and further characterised by rRNA gene restrictio
n patterns (ribotypes). Numerical analysis of these ribopatterns was perfor
med together with 19 reference LAB strain patterns in order to identify the
isolates to species level. The strains were divided with HindIII and EcoRI
ribopatterns into ten and nine clusters at the similarity level of 65% and
50%, respectively. The Leuconostoc-clusters and the Lb. sakei/Lb. curvatus
-clusters formed the two main groups. Only one isolate was identified as La
ctobacillus plantarum and no Carnobacterium strains were discovered. For bo
th enzymes, the 35 isolates possessing six individual ribotypes and forming
five clusters could not be identified further with the reference strains u
sed. The relative proportion of Leuconostoc mesenteroides subsp. mesenteroi
des was higher in all samples stored at 4 degrees C. Most of the Leuconosto
c citreum were found in the samples stored at 8 degrees C, and particularly
in the nitrite-treated samples. (C) 1999 Elsevier Science B.V. All rights
reserved.