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4.2 -
Results
4.2.1 -
Sampling and bacterial isolation
During a two month sampling period over the 1999/2000 austral summer, 41
lakes were sampled with the aid of helicopter support. Two of these lakes, Ace and
Pendant, were depth sampled because they had sufficient ice cover thickness to support
the necessary
ice drilling/coring equipment,
depth sampling equipment and personnel.
The majority of other lakes did not have sufficient ice cover thickness to support depth
sampling activity. These were, Williams, Rookery, Club, Ekho, Triple, Deep, Shield,
Oval, Druzhby, Tassie, Trident, Pointed, Verenteno, Calendar, Stinear, Jabs, Hand,
Dingle, Crooked, Oblong, Lebed, Anderson, Scale, Collerson, Medusa, Pauk, Zve: da.
Braunsteffer, Abraxas, Organic, Cemetery, Laternula, and Angel 2. For a number of
lakes, i. e. Watts, Nicholson, Nottingham, the lakes from the Larsemann Hills region
(Larsemann 73 and Reid), and Beaver lake, samples were taken during other sampling
programmes and as such these were not targeted for depth analysis. Surface water (within
the top 1 meter from the surface) sampling provided a cursory analysis of bacterial AFl'
activity from each lake, a spot test from which a more thorough, focused study could be
developed on those lakes which demonstrated surface bacterial populations with a high
instance of AFP activity (Chapter 3).
Over the whole sampling period 866 bacterial cultures were isolated from surface
water samples of the 41 individual lakes and depth samples with replicate samples on five
detailed study lakes.
4.2.2 -
Gram staining and cellular/colony morphology
Approximately
87% of bacterial isolates were Gram negative. Colony
morphology was dominated by mucoid colonies. These polysaccharide rich colonies
could indicate a UV protective strategy. Noted morphologies included irregular. undulate,
dry colonies, and punctiform, entire, moist/dry colonies.
Gram negative cellular morphology was dominated by rods (-98%), however,
these rod morphologies did vary in length (actual sizes were not recorded) and type, such
as straight, club-shaped and long, thin curved rods. The remaining bacterial isolates were
reported as coccoid (Appendix BI). It was possible that some of the Gram positive
bacteria could have been contaminants.
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