Study of Flavobacterium strains isolated from Antarctic aquatic and terrestrial samples
The microbial diversity on Antarctica is largely under-explored however these baseline data are necessary to observe future changes in biodiversity and taxonomic composition due to ecosystem change and/or human introduction. As part of the AMBIO-project that aims to explore bacterial distribution pa...
| Main Authors: | , , , , |
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| Format: | Conference Object |
| Language: | English |
| Published: |
2009
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| Subjects: | |
| Online Access: | https://biblio.ugent.be/publication/936641 http://hdl.handle.net/1854/LU-936641 |
| Summary: | The microbial diversity on Antarctica is largely under-explored however these baseline data are necessary to observe future changes in biodiversity and taxonomic composition due to ecosystem change and/or human introduction. As part of the AMBIO-project that aims to explore bacterial distribution patterns in Antarctica, nine samples, both terrestrial and aquatic, from different regions were investigated. Isolations were made using several conditions and strains were then subjected to rep-PCR fingerprinting as a fast screening to eliminate duplicate isolates. Cluster analysis of fingerprint patterns using BioNumerics software revealed a number of clusters (cut-off level 80%) of similar strains and a number of separate isolates. Representatives were used in partial 16S rRNA gene sequencing to obtain a first approximate identification. The results show a large diversity, distributed over the major phylogenetic groups and only little overlap between the samples. We focussed on the genus Flavobacterium because several of the isolated clusters and strains that were found in this genus show low similarity values with neighbouring sequences in the EMBL-database and thus may represent new species. The 16S rRNA gene sequence was completed and fatty acid analysis as well as some phenotypic tests (API® -20E, API®-20NE and a selection of biochemical growth and degradation tests) were performed. The obtained 16S rRNA gene dendrogram shows that some reference species are very closely related to each other. This makes it difficult to use the 16S rRNA gene to discriminate between potential new species and reference strains. Therefore a housekeeping gene, gyrB is being sequenced and, if required DNA-DNA hybridizations will be carried out, to establish whether these isolates can be described as new species. |
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