Characterisation of lactic acid bacteria from spoiled, vacuum-packaged, cold-smoked rainbow trout using ribotyping

Abstract

A total of 405 lactic acid bacteria (LAB) isolated from spoiled, vacuumpackaged, salted, sodium nitrite-or potassium nitrate-treated, cold-smoked rainbow trout stored at 4ºC or 8ºC were characterised and identified using a molecular method. The isolates were initially classified according to their restriction endonuclease profiles using HindIII and EcoRI restriction endonucleases and further characterised by rRNA gene restriction patterns (ribotypes). Numerical analysis of these ribopatterns was performed 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 asLactobacillus plantarum and no Carnobacterium strains were discovered. For both enzymes, the 35 isolates possessing six individual ribotypes and forming five clusters could not be identified further with the reference strains used. The relative proportion of Leuconostoc mesenteroides subsp. mesenteroides was higher in all samples stored at 4ºC. Most of the Leuconostoc citreum were found in the samples stored at 8ºC, and particularly in the nitritetreated samples.

Characterization and identification of lactic acid bacteria in “morcilla de Burgos”

“…Hitchener et al (1982) found a high level of heterofermentative bacteria (75%) although in this work most of the isolates were L-lactate producers and they called them as atypical Betabacteria, which were later identified as Carnobacterium species (Shaw and Harding, 1985). Björkroth et al (2000) found Leuconostoc gasicomitatum sp. nov. dominating (57% of the total LAB microflora) in a tomato-marinated, raw broiler meat strip product packaged under modified atmosphere.…”

“…gasicomitatum. The latest species has been recently described by Björkroth et al (2000) in spoiled raw tomato-marinated broiler meat strips packaged under modified-atmosphere conditions. Although isolates from group B1 (Lc.…”

“…Genomic blots were made using a vacuum device (Vacugene, Pharmacia, Uppsala, Sweeden) and rDNA probe for ribotyping was labelled by reverse transcription (AMV-RT, Promega, Madison, Wisconsin, USA) and Dig DNA Labelling Kit (Roche) as previously described by Blumberg et al (1991). Membranes were hybridised at 68ºC as described by Björkroth and Korkeala (1996a Korkeala, 1996bKorkeala, , 1997Lyhs et al, 2000;Björkroth et al, 1998Björkroth et al, , 2000Björkroth et al, , 2002. For numerical analysis, ribopatterns were scanned using a Hewlett Packard (Boise, Idaho, USA) ScanJet 4c/T scanner and analysed using the GelCompar II software package (Applied Maths, Kortrijk, Belgium).…”

“…Genotypic methods have a higher discriminatory power and in this sense the efforts of the current bacterial taxonomy are oriented to a polyphasic approach, which involves phenotypic and genotypic characterisation (Vandamme et al, 1996). Ribotyping technique that combines Southern hybridisation of chromosomal DNA fingerprints with the uses of Escherichia coli rRNA probes has revealed as a powerful tool in the classification of LAB (Rodtong and Tannock, 1993;Korkeala, 1996a, 1996b;Björkroth and Korkeala 1997;Björkroth et al, 1998;Lyhs et al, 2000;Björkroth et al, 2000, Satokari et al, 2000.…”

Developing microbial spoilage population in vacuum-packaged charcoal-broiled European river lamprey (Lampetra fluviatilis)

“…Jeppesen and Huss (1993) reported that all isolated LAB from samples of vacuum-packaged minced herring were Leuconostoc spp. Lyhs et al (1999) found Leuconostoc mesenteroides subsp. mesenteroides, Leuconostoc citreum, Lactobacillus sakei and Lactobacillus curvatus to be the main species associated with spoilage of vacuum-packaged cold-smoked rainbow trout.…”