STRIVE - Environmental Protection Agency

N. Touzet (2008-FS-EH-3-S5)
Figure 3.35. Succession of spherical cyanobacteria inferred from denaturent gradient gel electrophoresis
(DGGE) analysis in Lough Corrib and Ballyquirke Lough (a) together with the grouping of samples based on
hierarchical clustering (b).
Figure 3.36. Segregation of the denaturent gradient gel electrophoresis (DGGE) bands for spherical
cyanobacteria (a) according to their maximum intensity and frequency of occurrence in both Lough Corrib
and Lough Ballyquirke. Segregation of stations in the two lakes based on their spherical cyanobacteria
richness and abundance (b).
with those from August significantly greater than those
from June and July (ANOVA, F = 13.02, p < 0.01).
Individual bands from groups B, C and D were
successfully excised from the gels and re-amplified
prior to purification and sequencing. The occurrence
of the indicator bands was assessed in relation to
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environmental descriptors using Fisher’s exact test
(Table 3.9). In particular, bands 15, 22, 28, 46, 49 and
52 for spherical cyanobacteria showed, for each lake,
significant correlations with the descriptors pertaining
to the time of the summer, surface chlorophyll-a
levels, light penetration and inorganic nitrogen levels.