ý.,,: V. ý ýý . - Nottingham eTheses - University of Nottingham

phylogeny. This same relationship was demonstrated by the Alu I ARDRA analysis.
where isolate 732 (Enterobacter) demonstrated a close relationship with isolates 39 and
86 (Pseudoalteromonas; Fig 5.2c). Bowman et al. (2000) identified the species
Enterobacter aerogenes from a clone library of the hypersaline sediment community of
Deep Lake (Vestfold Hills), but it was suggested that this clone might be a PCR
contaminant (Bowman et al., 2000; as with Stenotrophomonas maltophilia. section
5.3.2.4, isolates 492 & 47). However, the isolation of E. agglomerans. which has a 9411/o
homology with E. aerogenes, from the nearby Ace Lake in the current study adds further
precedent to the presence of this genus in the Antarctic environment. Further to this, the
PCR preparations in the current study were made from high quality genomic DNA, and
therefore were not subject to the same level of PCR contamination probability as with the
Bowman et al. (2000) study where PCR preparations where made from `very low yield'
DNA (Bowman et al., 2000). Enterobacter agglomerans or as it is now known Pantoea
agglomerans, is more commonly found in associations with plant materials, animals and
humans (Lindh et al., 1991), however it has been shown to be ice-nucleation active and
be cold adapted, showing a wide range of cold acclimation protein changes (Kozloff et
al., 1983; Deininger et al., 1988; Koda et al., 2000; Koda et al., 2001). It is also known to
have been isolated from a saline pond (Francis et al., 2000) and therefore has shown the
ability to be halotolerant as well as psychrotrophic. Therefore, this identification is not
remarkable, as E. agglomerans has shown the ability to adapt to such an environment as
Ace Lake. However, there is also a possibility that this isolate could be a PCR
contamination but there is nothing to support this.
5.3.2.8 -
The Idiomarina loihiensis group, isolate 53
Isolate 53 was identified as being 99.3% related to Idiomarina loihiensi. s'. a
bacterial isolate which was first isolated from the hydrothermal fluids of a submarine
volcano in Hawaii (Donachie et al., unpublished). Isolate 53 was isolated from Triple
Lake on September 7t" 2000 at 8m. The water temperature was -13.3°C and the salinity
was 185ppt. Although the sequence relationship between isolate 53 and I. loihiensi. s
suggests they are the same species it is almost certain that they are different strains as
they exhibit an ability to survive in two very different extreme environments.
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