Fig. 3: Onboard experiments for deliquescence events and microbial biomarker profiling under Antarctic freezing temperatures.
From: Microbial biogeography along a 2578 km transect on the East Antarctic Plateau
A Deliquescence experiment. A plastic container filled with NaCl and sensors for conductivity (C), relative humidity (RH) and temperature (T) inserted in the salt. B Values of RHice and T measured in the air (dotted lines) and within NaCl (solid lines) during the transect across the Antarctic Plateau from 12/21/2018 to 02/01/2019. Black areas show periods when RHice within the salt remained constant, and above the equilibrium RH of saturated NaCl brines. This could be due to the formation of thin briny films within the salt via deliquescence. During those periods, the temperature within the salt transiently rose above the eutectic (grey areas). Also indicated are the deliquescence RH and eutectic temperature of saturated NaCl brines. C On site fluorescence sandwich immunoassay (FSIA) with LDChip at M site, showing a portion of LDChip with several positive immunodetections on triplicate spot pattern. Cartoon shows a sandwich immunoassay with an immobilized antibody (Ab), the target biomarker captured (yellow figure), and the fluorescent tracer antibody (FTAb). Squares and numbers indicate the antibodies whose relative fluorescence units where plotted with the entire LDChip results after a single assay with each of 1 m section of M drill (0-1 m, 1-2 m, 2-3 m, 3-4 m) on the right (D), which correspond to: 1, Acidithiobacillus thiooxidans; 2, Tessaracoccus lapidicaptus (Actinobacteriota); 3, Bacillus subtilis spores (Firmicutes); 4, Bacillus subtilis biofilm (Firmicutes); 5, Leptolyngbya boryana (Cyanobacteria); 6, GroEL chaperonine; 7, NifD nitrogenase component; 8, DhnA drought, low temperature, high salinity protectant dehydrin from cyanobacteria; 9, Acidithiobacillus ferrooxidans; 10, NirS nitrite reductase protein; 11, environmental biofilm enriched in iron oxidizing bacteria; 12, Arcobacter sp.
