| 1. |
- Olsson, Crister, et al.
(författare)
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The bacterial flora of fresh and chill-stored pork: analysis by cloning and sequencing of 16S rRNA genes.
- 2003
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Ingår i: International Journal of Food Microbiology. - 0168-1605. ; 83:3, s. 245-252
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Tidskriftsartikel (refereegranskat)abstract
- The composition of the initial bacterial flora of pork and the development of the flora after storage at +4 °C for 4 days were analysed by amplification, cloning and sequencing of 16S rDNA. A total of 122 clones were obtained, with lengths of ≥400 nucleotides and ≥95% similarity to database sequences. Nineteen clones were similar to sequences in database not assigned to any genera. Fourteen different genera were represented in clones from fresh meat, with 36.5% of the clones most resembling Acinetobacter and 17.3% resembling Staphylococcus and Macrococcus. After storage, the clones were composed of six different genera, with 44.3% resembling Pseudomonas, 17.1% resembling Aeromonas and only 14.3% resembling Acinetobacter. This study shows that the overall pattern of the initial and chill-stored pork flora, as shown by a molecular approach, was in agreement with results obtained in previous studies using traditional cultivation methods.
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| 2. |
- Olofsson, Tobias, et al.
(författare)
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Composition of the bacterial population of refrigerated beef identified with direct 16S rRNA gene analysis and pure culture technique
- 2007
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Ingår i: International Journal of Food Microbiology. - : Elsevier BV. - 0168-1605. ; 118:3, s. 233-240
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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