Saturday, October 3, 2009

Pink Polar Caps and Purple Snows of Olympus...

Concept thoughts....All about the bacteria...experiencing snow blindness.
Watermelon snow, also called snow algae, is snow
SnowSnow is a type of precipitation in the form of crystalline water ice, consisting of a multitude of snowflakes that fall from clouds. The process of this precipitation is called snowfall.... that is reddish or pink in color, with the slight scent of a fresh watermelon
This type of snow is common during the summer in alpine and coastal polar regions worldwide, such as the Sierra Nevada Here, at altitudes of 10,000 to 12,000 feet (3,000–3,600 m), the temperature is cold throughout the year, and so the snow has lingered from winter storms. Compressing the snow by stepping on it or making snowballs leaves it looking red. The first accounts of watermelon snow are in the writings of Aristotle
Watermelon snow has puzzled mountain climbers, explorers, and naturalist
for thousands of years, some speculating that it was caused by mineral deposits or oxidation products that were leached from rocks.In May 1818, four ships sailed from England to search for the Northwest Passage and chart the Arctic coastline of North America. Severe weather made them finally turn the ships back, but the expedition made valuable contributions to science. Captain John Ross noticed crimson snow that streaked the white cliffs like streams of blood as they were rounding Cape York Cape York (Greenland)Cape York is a headland on the northwestern coast of Greenland, in northern Baffin Bay. It was the one of many places visited in 1894 by Admiral Robert Peary during his second expedition to the Arctic.... on the northwest coast of Greenland
Bacterial cultures have been found in Siberian permafrost at an average temperature of around -10°C. The permafrost is estimated at between one thousand and one million years. The suggestion has been made that despite the low temperature, the bacteria must have been active, otherwise they could not have survived for so long. Supporting evidence for low-temperature activity is the recent discovery of bacteria in snow and ice in the surface layers of Antarctica, which indeed have metabolic activity at -12°C to -17°C. It is interesting to note that the Antarctica researchers discovered members of Deinococcus, a genus of bacteria that was already known in the preserved food industry for its ability to withstand ionizing radiation, including X-rays and radioactivity. This is remarkable, as such high irradiations are not present in the natural environment, and it was unclear what advantage this ability could give. The answer could be that in the Antarctica snowfields, Deinococcus species are subject to intensive UV irradiation which causes ionisation.12 This example again illustrates the remarkable ability of some bacteria to survive under extreme conditions.

Most bacteria find it difficult to survive when subjected to high temperature, radiation (including UV irradiation), acidic or basic environments, oxidizing agents (including oxygen), certain inorganic compounds, mechanical stress and wet conditions.10 Nevertheless, many of these conditions can be favourable for bacteria if they occur in a water inclusion in an evaporite, even if water is present. Although salt is detrimental to most bacteria, some such as B. marismortui can survive as spores or even flourish under saline conditions below 25% w/v.
Microbial growth or metabolic activity has been reported in permafrost bacteria at 10°C (11) and in the antarctic cryptoendolithic microbial community at temperatures between 5 and 10°C (7, 28), and the temperature limit of bacterial growth in frozen food is generally considered to be 8°C (9). In arctic and antarctic lichens, photosynthetic activity has been observed in a similar temperature range (12) and, more recently, at 17°C (23). However, no quantitative measurements of the dynamics of metabolic activity or of growth have been described. We attempted to quantify metabolic activity at subzero temperatures in the native bacterial population of Siberian permafrost by measuring the incorporation of sodium acetate into lipids over a 550-day period.
Ref:Applied and Environmental Microbiology, August 2000, p. 3230-3233, Vol. 66, No. 80099-2240/00/Metabolic Activity of Permafrost Bacteria below the Freezing Point E. M. Rivkina,1, E. I. Friedmann,1,* C. P. McKay,2 and D. A. Gilichinsky3
Abstract:The carbon metabolism of the cryptoendolithic microbiota of sandstones from the Ross Desert of Antarctica was studied in situ and in vitro. Organic and inorganic carbon compounds were metabolized by the microbiota, with bicarbonate incorporation into community lipids occurring primarily in the light. Photosynthesis was also affected by temperature, with a minimum activity at -5 degrees C, an optimum activity at 15 degrees C, and complete inhibition at 35 degrees C, indicating that the cryptoendolithic community was psychrophilic. The primary source of CO2 for photosynthesis in situ was the atmosphere. CO2 may also be photometabolized by using the carbon produced from respiration within the endolithic community. Photosynthesis occurred maximally when the microbiota was wet with liquid water and to a lesser extent in a humid atmosphere. This simple microbial community, therefore, exists under extremes of water, light, and temperature stress which affect and control its metabolism.
Ref: Appl Environ Microbiol. 1988 April; 54(4): 960-965 Carbon metabolism of the cryptoendolithic microbiota from the Antarctic desert. J R Vestal
Olympus Mons
The purple nonsulfur bacteria Rhodospirillum rubrum SMG 107, Rhodopseudomonas capsulata SMG 155, Rps. sphaeroides SMG 158 and Rps. palustris SMG 124 were tested for a possible utilization of sulfide. The first three strains were found to oxidize sulfide to extracellular elemental sulfur only, whereas Rps. palustris SMG 124 converted sulfide into sulfate without intermediate accumulation of elemental sulfur. Growth ceased at lower sulfide concentrations than usually found with purple sulfur bacteria. In consequence of the low sulfide tolerance information on the specific growth rates obtainable with sulfide as photosynthetic electron donor could not be provided by cultivation in batch cultures. Sulfide-limited chemostat cultures of Rps. capsulata SMG 155 showed that the maximum specific growth rate was close to 0.14 h-1 (doubling time 5 h). Sulfide was converted into extracellular elemental sulfur at all dilution rates tested. The maximum specific growth rate of Rps. palustris SMG 124 was found to be much lower (less than 0.03 h-1). Sulfate was the only product of the conversion of sulfide.
Theo A. Hansen1 and Hans van Gemerden, Laboratory for Microbiology, University of Groningen, The Netherlands Received: 16 June 1972
Prokaryotes are abundant and active in polar environments (3, 18). Antarctic lakes are particularly interesting in this respect because they are exclusively microbial ecosystems (28, 42). Several permanently ice-covered lakes exist in the McMurdo Dry Valleys, Antarctica. The major Taylor Valley lakes, Hoare, Bonney, and Fryxell, were formed by glacial deepening and have a permanent ice cover that varies from 2 to 6 m thick (10, 28). Among Taylor Valley lakes, the ice cover of Lake Hoare is the most rugged (Fig. (Fig.1A).1A). Lake Hoare is also the most oligotrophic and oxic of Taylor Valley lakes; dissolved organic carbon (DOC) levels are below 0.5 mg/liter, salt is present in only trace amounts, and the water column is supersaturated with oxygen to a depth of 24 m

Appl Environ Microbiol. 2007 May; 73(9): 3077–3083.
Published online 2007 March 16. doi: 10.1128/AEM.00085-07.
PMCID: PMC1892853
Cold-Active Chemoorganotrophic Bacteria from Permanently Ice-Covered Lake Hoare, McMurdo Dry Valleys, Antarctica
Kate M. Clocksin, Deborah O. Jung, and Michael T. Madigan

Schlegel, H.G., General Microbiology, 7th Edition, Cambridge, 1993.
Shi, T., Reever, R.H., Gilchinsky, D.A. and Friedman, E.I., Characterisation of viable bacteria from Siberian Permafrost by 16S rDNA sequencing, Microb. Ecol., 33:169–179, 1997.
Carpenter, E.J., Lin, S. and Capone, D.G., Bacterial Activity in South Pole Snow, Appl. Env. Microb., 66:4514–4517, 2000.
Makarova, K.S., Aravind, L., Wolf, Y.I., Tatusov, R.L., Minton, K.W., Koonin, E.V. and Daly, M.J., Genome of the extremely radiation-resistant bacterium Deinococcus radiodurans viewed from the perspective of comparative genomics, Microbiol. Molec. Biol. Rev., 65:44–79, 2001.