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with two bands in the Triple Lake, 4m September community profile (Fig. 6.3b, Lane
13). Isolate 494 (Fig. 6.3b, Lane 7) showed three bands present within the community
profile of Ace Lake, 4m September (Fig. 6.3b, Lane 10), but was isolated from Pedant
Lake at Om during November. Isolate 583 (Fig 6.3b, Lane 9) matched with a single band
from the Pendant Lake, Om September community profile (Fig 6.3b, Lane 11), however.
it was isolated from Triple Lake at Om during September (Table 5.2). Isolate 213 (Fig
6.3a, Lane 4) matched with two bands from the Triple Lake. 4m September profile (Fig
6.3b, Lane 13). As previously stated, this is the only isolate which was identified as being
present within a community profile from the lake, depth and time from which it was
actually isolated.
The pure culture AFP profiles which were present within the community profiles
(Fig 6.3b) were not represented by high intensity bands, possibly indicating that the AFP
active isolates were generally not the dominant bacteria within the DGGE community
profiles, except isolate 213 which was represented by the most dominant bands in the
Triple Lake, 4m September profile (Fig 6.3b, Lane 13).
In figure 6.3a, there is a single band present in multiple lanes (Lanes 4.5,6,7,8,
9,10,11,13 & 14) which contain pure culture profiles. The presence of this band was
considered to be artefactual as it was not present in any of the replicate profiles
in figure
6.3b. It is possible that this band could represent a PCR contaminant that affected all
these isolates during PCR (Section 6.3.2.4.4).
6.2.1.1 -
Assessment of 16S rRNA operon heterogeneity in M. protea
Isolates 154,54,744,794 and Marinomonas protea (Fig 6.1, Lanes, 9-11 & 13 -
14
respectively) all demonstrated 100% 16S rDNA sequence similarity to each other
(Chapter 5), however, they show variation in the number of 16S rRNA genes. Isolates
154,744 and M. protea all showed four putative copies of the gene whereas, as already
stated, isolates 54 and 794 showed only a single copy.
A DGGE gel was run to compare isolates 154,54,744 and 794 against
Marinomonas protea (Fig 6.3a -
lanes 9-11.13 & 14 respectively). The resultant bands
for each isolate were excised from the DGGE gel, the DNA was extracted (by suspension
of the excised band in water, at 4°C, overnight) and the V3 region was then re-amplified
162