Aqueous extracts of a Mars analogue regolith that mimics the Phoenix landing site do not inhibit spore germination or growth of model spacecraft contaminants Bacillus subtilis 168 and Bacillus pumilus SAFR-032

Germination of Spores of Astrobiologically RelevantBacillusSpecies in High-Salinity Environments

“…Especially under sub-optimal conditions, which will likely prevail in much more extreme extent on extraterrestrial planets or moons, germination responses and salt sensitivity of germination can be expected to be very variable among different species, hampering forward contamination risk assessment. What is more, extraterrestrial brines or salt oceans are almost certainly composed of a mixture of different salts (Marion et al, 2003;Sohl et al, 2010;Nicholson et al, 2012;Ojha et al, 2015;Stevenson et al, 2015), which will affect spore germination in a different, more complex way than NaCl . However, Nicholson et al (2012) showed that germination of B. subtilis 168 and B. pumilus SAFR-032 spores is, in principle, possible in aqueous extracts of a Mars analog regolith that mimics the Phoenix landing site.…”

“…Its spores have an outstandingly high resistance against UV radiation and H 2 O 2 , enabling this strain to withstand decontamination procedures (Link et al, 2004;Tirumalai et al, 2013). Bacillus pumilus SAFR-032 spores have previously been used for astrobiological experiments including prolonged exposure to real space conditions on board the International Space Station Nicholson et al, 2012;Vaishampayan et al, 2012). Although germination of B. pumilus has been investigated in complex media or when triggered by high pressure (Clouston and Wills, 1969;Nicholson et al, 2012), to our knowledge, no chemically defined nutrient germinant has been identified so far.…”

“…Bacillus pumilus SAFR-032 spores have previously been used for astrobiological experiments including prolonged exposure to real space conditions on board the International Space Station Nicholson et al, 2012;Vaishampayan et al, 2012). Although germination of B. pumilus has been investigated in complex media or when triggered by high pressure (Clouston and Wills, 1969;Nicholson et al, 2012), to our knowledge, no chemically defined nutrient germinant has been identified so far. However, L-alanine was reported to be conductive for germination when used in combination with Spizizen salts and tryptophan (Fajardo-Cavazos et al, 2008).…”

Survivability of Soil and Permafrost Microbial Communities after Irradiation with Accelerated Electrons under Simulated Martian and Open Space Conditions

“…Moreover, it is shown that econiches with liquid water and positive temperatures can occur on the current Mars [88,[90][91][92][93]. Terrestrial microorganisms can grow under combined low pressure, temperature, and anoxic atmosphere conditions [94], it can withstand the impact of Martian salts and strong oxidizers [95][96][97][98], and can survive in subzero brines [99,100]. If even slow repairing of cells' damages occurs, it can be of great effect during geological time.…”

Uso de soro de leite para obtenção de esporos de Bacillus atrophaeus ATCC 9372 e de biossurfactantes

“…Esporos de Bacillus atrophaeus são amplamente utilizados como indicadores biológicos para esterilização, em estudos de biodefesa e astrobiologia, métodos e desinfecção, extração de DNA, avaliação no tratamento de resíduos e potencial adjuvante ou veículo para vacinas e outras biopartículas (NICHOLSON et al, 2012;BERENDSEN et al;SELLA et al, 2014 …”