Further refs on life surviving at or nearly at saturation levels of salts:

Brine organisms and the question of habitat-specific adaptation.
Origins of Life and Evolution of Biospheres.
Volume 14, Numbers 1-4 / December, 1984
"Abstract Among the well-known ultrasaline terrestrial habitats, the Dead Sea in the Jordan Rift Valley and Don Juan Pond in the Upper Wright Valley represent two of the most extreme. The former is a saturated sodium chloride-magnesium sulfate brine in a hot desert, the latter a saturated calcium chloride brine in an Antarctic desert. Both Dead Sea and Don Juan water bodies themselves are limited in microflora, but the saline Don Juan algal mat and muds contain abundant nutrients and a rich and varied microbiota, includingOscillatoria,Gleocapsa,Chlorella, diatoms,Penicillium and bacteria.
In such environments, the existence of an array of specific adaptations is a common, and highly reasonable, presumption, at least with respect to habitat-obligate forms. Nevertheless, many years of ongoing study in our laboratory have demonstrated that lichens (e.g.Cladonia), algae (e.g.Nostoc) and fungi (e.g.Penicillium,Aspergillus) from the humid tropics can sustain metabolism down to –40°C and growth down to –10°C in simulated Dead Sea or Don Juan (or similar) media without benefit of selection or gradual acclimation. Non-selection is suggested in fungi by higher growth rates from vegetative inocula than spores. The importance of nutrient parameters was also evident in responses to potassium and reduced nitrogen compounds.
In view of the saline performance of tropicalNostoc, and its presence in the Antarctic dry valley soils, its complete absence in our Don Juan mat samples was and remains a puzzle.
We suggest that adaptive capability is already resident in many terrestrial life forms not currently in extreme habitats, a possible reflection of evolutionary selection for wide spectrum environmental adaptability."
http://www.springerlink.com/content/r0565304t64835nv/

Reports
The Enigma of Prokaryotic Life in Deep Hypersaline Anoxic Basins.
"Evidence that microbial life is possible at 5 M MgCl2 widens the picture of microbial adaptation to salinity. It has been suggested that primordial life on earth started in hyper-saline water (28, 29); furthermore, extra-terrestrial objects are known to contain brines exposed to evaporation, which results in an increase of divalent cations (30, 31). Our results indicate that microbial metabolism can proceed at significant levels in some of the most extreme terrestrial hyper-saline environments and lend further support to the possibility of extraterrestrial life."
Science 7 January 2005: Vol. 307. no. 5706, pp. 121 - 123.
http://www.sciencemag.org/cgi/content/full/307/5706/121

Interestingly, the first says fungi might survive in brines at the maximum temperature range that might appear at the Mars Phoenix landing site. Of course, the temperatures would fall to lower than this during the polar night and Winter. But perhaps they could go into suspended spore-like form then.
And the second gives references that argue life might have originated in hypersaline environments, in contrast to the Knoll view that it could not have started there.

Bob Clark