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Spore-Forming Thermophilic Bacterium within Artificial Meteorite Survives Entry into the Earth's Atmosphere on FOTON-M4 Satellite Landing Module.

Slobodkin A, Gavrilov S, Ionov V, Iliyin V - PLoS ONE (2015)

Bottom Line: So far, all experimental proof of this possibility has been based on tests with sounding rockets which do not reach the transit velocities of natural meteorites.The identity of the strain was confirmed by 16S rRNA gene sequence and physiological tests.This is the first report on the survival of a lifeform within an artificial meteorite after entry from space orbit through Earth's atmosphere at a velocity that closely approached the velocities of natural meteorites.

View Article: PubMed Central - PubMed

Affiliation: Winogradsky Institute of Microbiology, Russian Academy of Sciences, Prospect 60-letiya Oktyabrya 7/2, 117312 Moscow, Russia.

ABSTRACT
One of the key conditions of the lithopanspermia hypothesis is that microorganisms situated within meteorites could survive hypervelocity entry from space through the Earth's atmosphere. So far, all experimental proof of this possibility has been based on tests with sounding rockets which do not reach the transit velocities of natural meteorites. We explored the survival of the spore-forming thermophilic anaerobic bacterium, Thermoanaerobacter siderophilus, placed within 1.4-cm thick basalt discs fixed on the exterior of a space capsule (the METEORITE experiment on the FOTON-M4 satellite). After 45 days of orbital flight, the landing module of the space vehicle returned to Earth. The temperature during the atmospheric transit was high enough to melt the surface of basalt. T. siderophilus survived the entry; viable cells were recovered from 4 of 24 wells loaded with this microorganism. The identity of the strain was confirmed by 16S rRNA gene sequence and physiological tests. This is the first report on the survival of a lifeform within an artificial meteorite after entry from space orbit through Earth's atmosphere at a velocity that closely approached the velocities of natural meteorites. The characteristics of the artificial meteorite and the living object applied in this study can serve as positive controls in further experiments on testing of different organisms and conditions of interplanetary transport.

No MeSH data available.


Related in: MedlinePlus

Schematic illustration of FOTON-M4 satellite showing the position of the METEORITE experiment payload.Modified from original drawing supplied by the Russian Federal Space Agency at http://roscosmos.ru/20669/.
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pone.0132611.g002: Schematic illustration of FOTON-M4 satellite showing the position of the METEORITE experiment payload.Modified from original drawing supplied by the Russian Federal Space Agency at http://roscosmos.ru/20669/.

Mentions: Six 1.4-cm-thick basalt (from the mineralogical collection of Lomonosov Moscow State University) discs with a diameter of 7.0 cm were used as a model of the artificial meteorite in this part of the METEORITE experiment (Fig 1). For the placement of the dried microbial cultures, 24 wells, 2 mm in diameter, were drilled on the back side of the disc to a depth of 6 mm. Twelve wells in each disc were filled with dried cultures of T. siderophilus, while the other 12 wells were filled with cultures of other microorganisms (this will be the subject of a separate report). Prior to inoculation, the discs were wrapped in aluminum foil and sterilized by autoclaving (135°C, 2 h). After loading with microbial cultures, four discs were inserted into the holders (annular discs of phenolic silica, i.e. the same material as was used for the ablative capsule heat shield) and fixed on the exterior of the FOTON-M4 capsule. Two discs were fixed near the stagnation point (test), and two discs were fixed on the reverse side of the landing module (orbital control) (Fig 2). Two other discs were kept in the laboratory at ambient temperature (ground control).


Spore-Forming Thermophilic Bacterium within Artificial Meteorite Survives Entry into the Earth's Atmosphere on FOTON-M4 Satellite Landing Module.

Slobodkin A, Gavrilov S, Ionov V, Iliyin V - PLoS ONE (2015)

Schematic illustration of FOTON-M4 satellite showing the position of the METEORITE experiment payload.Modified from original drawing supplied by the Russian Federal Space Agency at http://roscosmos.ru/20669/.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4494708&req=5

pone.0132611.g002: Schematic illustration of FOTON-M4 satellite showing the position of the METEORITE experiment payload.Modified from original drawing supplied by the Russian Federal Space Agency at http://roscosmos.ru/20669/.
Mentions: Six 1.4-cm-thick basalt (from the mineralogical collection of Lomonosov Moscow State University) discs with a diameter of 7.0 cm were used as a model of the artificial meteorite in this part of the METEORITE experiment (Fig 1). For the placement of the dried microbial cultures, 24 wells, 2 mm in diameter, were drilled on the back side of the disc to a depth of 6 mm. Twelve wells in each disc were filled with dried cultures of T. siderophilus, while the other 12 wells were filled with cultures of other microorganisms (this will be the subject of a separate report). Prior to inoculation, the discs were wrapped in aluminum foil and sterilized by autoclaving (135°C, 2 h). After loading with microbial cultures, four discs were inserted into the holders (annular discs of phenolic silica, i.e. the same material as was used for the ablative capsule heat shield) and fixed on the exterior of the FOTON-M4 capsule. Two discs were fixed near the stagnation point (test), and two discs were fixed on the reverse side of the landing module (orbital control) (Fig 2). Two other discs were kept in the laboratory at ambient temperature (ground control).

Bottom Line: So far, all experimental proof of this possibility has been based on tests with sounding rockets which do not reach the transit velocities of natural meteorites.The identity of the strain was confirmed by 16S rRNA gene sequence and physiological tests.This is the first report on the survival of a lifeform within an artificial meteorite after entry from space orbit through Earth's atmosphere at a velocity that closely approached the velocities of natural meteorites.

View Article: PubMed Central - PubMed

Affiliation: Winogradsky Institute of Microbiology, Russian Academy of Sciences, Prospect 60-letiya Oktyabrya 7/2, 117312 Moscow, Russia.

ABSTRACT
One of the key conditions of the lithopanspermia hypothesis is that microorganisms situated within meteorites could survive hypervelocity entry from space through the Earth's atmosphere. So far, all experimental proof of this possibility has been based on tests with sounding rockets which do not reach the transit velocities of natural meteorites. We explored the survival of the spore-forming thermophilic anaerobic bacterium, Thermoanaerobacter siderophilus, placed within 1.4-cm thick basalt discs fixed on the exterior of a space capsule (the METEORITE experiment on the FOTON-M4 satellite). After 45 days of orbital flight, the landing module of the space vehicle returned to Earth. The temperature during the atmospheric transit was high enough to melt the surface of basalt. T. siderophilus survived the entry; viable cells were recovered from 4 of 24 wells loaded with this microorganism. The identity of the strain was confirmed by 16S rRNA gene sequence and physiological tests. This is the first report on the survival of a lifeform within an artificial meteorite after entry from space orbit through Earth's atmosphere at a velocity that closely approached the velocities of natural meteorites. The characteristics of the artificial meteorite and the living object applied in this study can serve as positive controls in further experiments on testing of different organisms and conditions of interplanetary transport.

No MeSH data available.


Related in: MedlinePlus