Survival of microbial cultures on mineral while passing dense layers of the atmosphere
Abstract
The purpose of the experiment is to study the possibility of extremophilic microorganisms survival in meteorite-like mineral while passing through the dense layers of the atmosphere. For this purpose cultures of bacteria were placed into the holes made in basalt pieces fixed to the outer wall of the spacecraft Bion M1. Control: similar materials placed in the outer container, prevented from overheating in the dense layers of the atmosphere by lid. In the flight experiment five strains of thermophilic bacteria and 2 strains of hyperthermophilic archaea from the collection of the Institute of Microbiology, RAS were used. In addition, microorganisms were selected from the collection of the Institute of Biomedical Problems, isolated from the environment objects of ISS: 10 fungal cultures and a culture of bacteria Bacillus pumilus. For thermophiles and hyperthermophiles the ability to redox interactions with minerals is considered as a priority physiological property. Ability of thermophiles to anaerobic growth also meets the conditions of the experiment - testing cell survival of microorganisms in the conditions of extraterrestrial space and ancient anaerobic atmosphere of the Earth. After 30-days flight in orbit control all spore-forming microorganisms have been successfully survived. Hyperthermophilic archaea growth in all control was significantly less intensive. Meanwhile, in one experimental samples there was obtained signs of survival of spore forming bacteria culture Carboxydocella ferrireducens. However, the maximum concentration of cells was 2 orders of magnitude below the values characteristic of an actively growing culture of the microorganism. Due to damage of holes in the stone, this result was obtained only in one replicate and for final prove of survival of C. ferrireducens when returning through the dense layers of the atmosphere it is necessary to repeat the experiment It should be noted that an important indicator of the possibility of survival of C. ferrireducens was the consumption of CO and the stoichiometric formation of hydrogen grown experimental culture because of hydrogen carboxidotrophy, which is distinctive physiological property of this group of microorganisms. Consumption of micromolar amounts of CO were also recorded for Archaeoglobus fulgidus. However, we failed to detect growth in the culture. In addition, as a result of the experiment, one culture of B.pumilus from IBMP collection survived. Its identity with original culture studies was confirmed by 16S RNA testing.
- Publication:
-
40th COSPAR Scientific Assembly
- Pub Date:
- 2014
- Bibcode:
- 2014cosp...40E3512V