DETERMINATION OF PROKARYOTIC PERCENT SURVIVABILITY; EXAMINATION OF OXIDATIVE DAMAGE AS MECHANISM FOR VIABILITY OF MICROBIAL MAT TRANSITING MARS ANALOGOUS CONDITIONS

Examination of desiccation resistant bacteria are at the forefront of current microbial, astrobiological studies due to evolved adaptive capabilities. Bacteria were collected from sediment in Bad Water, California and prepared for high-altitude exposure via weather balloon launch. The extreme stresses this coupled microbial system experiences day to day in its natural habitat are a good analog for potential extremophilic communities on Mars. The transient stress introduced in this experiment includes a 90,000 ft altitude exposure during a two hour flight. Two flights were conducted on different sample sets from the same location. Environmental data were collected during the flight and the samples were examined pre- and post-flight. The transient stresses affecting/impacting microbial viability are pressure (0.01 atm), temperature (-80 degrees Celsius), ultraviolet radiation (UV) and were measured by the implementation of Arduino-based sensors.

Survivability of prokaryotic bacteria in the sample was determined through Baclight which is a live/dead assay that allows for accurate cell counts of live and dead cells through fluorescent dyes. Oxidative damage was assessed by CellRox Green which allows for the measurement of oxidative stress by examining the fluorescence of the cell-permeable dye when cell contents are oxidized. These two tests performed in tandem and analyzed through fluorescence microscopy in conjunction with flow-cytometry allow for a study of microbial viability as well as the mechanism for microbial death. We propose that a coupled microbial mat system may have evolved advantageous holistic adaptations to compelling environmental stress. We expect to observe strong microbial viability comparing pre and post flight samples in both sediment and culture, this viability we believe will be a function of the symbiotic relationship evident in the coupled microbial system.