The Open UniversitySkip to content
 

Diverse microbial species survive high ammonia concentrations

Kelly, Laura C.; Cockell, Charles S. and Summers, Stephen (2012). Diverse microbial species survive high ammonia concentrations. International Journal of Astrobiology, 11(2) pp. 125–131.

DOI (Digital Object Identifier) Link: https://doi.org/10.1017/S147355041200002X
Google Scholar: Look up in Google Scholar

Abstract

Planetary protection regulations are in place to control the contamination of planets and moons with terrestrial micro-organisms in order to avoid jeopardizing future scientific investigations relating to the search for life. One environmental chemical factor of relevance in extraterrestrial environments, specifically in the moons of the outer solar system, is ammonia (NH3). Ammonia is known to be highly toxic to micro-organisms and may disrupt proton motive force, interfere with cellular redox reactions or cause an increase of cell pH. To test the survival potential of terrestrial micro-organisms exposed to such cold, ammonia-rich environments, and to judge whether current planetary protection regulations are sufficient, soil samples were exposed to concentrations of NH3 from 5 to 35% (v/v) at−80 °C and room temperature for periods up to 11 months. Following exposure to 35% NH3, diverse spore-forming taxa survived, including representatives of the Firmicutes (Bacillus, Sporosarcina, Viridibacillus, Paenibacillus, Staphylococcus and Brevibacillus) and Actinobacteria (Streptomyces). Non-spore forming organisms also survived, including Proteobacteria (Pseudomonas) and Actinobacteria (Arthrobacter) that are known to have environmentally resistant resting states. Clostridium spp. were isolated from the exposed soil under anaerobic culture. High NH3 was shown to cause a reduction in viability of spores over time, but spore morphology was not visibly altered. In addition to its implications for planetary protection, these data show that a large number of bacteria, potentially including spore-forming pathogens, but also environmentally resistant non-spore-formers, can survive high ammonia concentrations.

Item Type: Journal Item
Copyright Holders: 2012 Cambridge University Press
ISSN: 1475-3006
Keywords: Actinobacteria; ammonia; Clostridium; Firmicutes; Proteobacteria; spores
Academic Unit/School: Faculty of Science, Technology, Engineering and Mathematics (STEM)
Item ID: 41346
Depositing User: Stephen Summers
Date Deposited: 18 Nov 2014 16:52
Last Modified: 10 Apr 2019 10:01
URI: http://oro.open.ac.uk/id/eprint/41346
Share this page:

Metrics

Altmetrics from Altmetric

Citations from Dimensions

Actions (login may be required)

Policies | Disclaimer

© The Open University   contact the OU