Composition of the bacterial population of refrigerated beef identified with direct 16S rRNA gene analysis and pure culture technique
Författare
Summary, in English
The composition of the dominating population of freshly cut beef, and beef stored at 4 degrees C for 8 d, was studied by direct analysis of the 16S rRNA gene (PCR amplification, cloning and sequencing) and compared with pure culture technique where the isolates picked from the viable plate count were identified by sequencing of the 16S rRNA gene. The composition of the bacterial population was recorded at two different time points, at the start when the viable plate count of the meat was 4 x 102 colony forming unit (cfu) per cm(2) and when it was 5 x 107 cfu per cm(2). Direct gene analysis by PCR amplification generated 30 clones, and 79 isolates were picked from the plate count, and identified by 16S rRNA gene sequencing. At the low initial bacterial load of the beef, the two sampling strategies showed variations in the composition of species. Direct 16S rRNA gene analysis revealed a domination of Bacillus-like sequences while no such sequences were found in isolates from the viable plate count. Instead the population of the plate count was dominated by Chryseobacterium spp. In contrast, the two sampling strategies matched on the multiplying beef population, where both methods indicated Pseudomonas spp. as the dominating group (99% of the population-sequences), irrespectively of sampling strategy. Pseudomonas panacis/Pseudomons brennerii was the dominating taxon (99% similarity to type strain), but sequences with highest similarity to Pseudomonas lundensis (99%), Pseudomonas beteli (99%) and Pseudomonas koreensis (100%) were also found. (C) 2007 Elsevier B.V. All rights reserved.
Avdelning/ar
- Avdelningen för medicinsk mikrobiologi
- Avdelningen för livsmedel och läkemedel
- Department of Food Technology, Engineering and Nutrition
Publiceringsår
2007
Språk
Engelska
Sidor
233-240
Publikation/Tidskrift/Serie
International Journal of Food Microbiology
Volym
118
Issue
3
Länkar
Dokumenttyp
Artikel i tidskrift
Förlag
Elsevier
Ämne
- Food Engineering
Nyckelord
- beef
- Pseudomonas
- 16S rDNA cloning
- cultivation
- bacterial population
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 0168-1605