Extreme spore UV resistance of Bacillus pumilus isolates obtained from an ultraclean Spacecraft Assembly Facility

Microb Ecol. 2004 Feb;47(2):159-63. doi: 10.1007/s00248-003-1029-4. Epub 2003 Sep 17.


Recent environmental microbial sampling of the ultraclean Spacecraft Assembly Facility at NASA Jet Propulsion Laboratory (JPL-SAF) identified spores of Bacillus pumilus as major culturable bacterial contaminants found on and around spacecraft. As part of an effort to assess the efficacy of various spacecraft sterilants, purified spores of 10 JPL-SAF B. pumilus isolates were subjected to 254-nm UV and their UV resistance was compared to spores of standard B. subtilis biodosimetry strains. Spores of six of the 10 JPL-SAF isolates were significantly more resistant to UV than the B. subtilis biodosimetry strain, and one of the JPL-SAF isolates, B. pumilus SAFR-032, exhibited the highest degree of spore UV resistance observed by any Bacillus spp. encountered to date.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Analysis of Variance
  • Bacillus / physiology*
  • Environment, Controlled*
  • Environmental Microbiology*
  • Radiation Tolerance / physiology*
  • Spacecraft*
  • Spores, Bacterial
  • Ultraviolet Rays*