FIG 2.

Measurement of UV₂₅₄ (dosages of 0, 200, and 500 J/m²) resistance from a large collection of ISS survivors and in-depth measurement of UV₂₅₄ resistance (dosages of 0 to 900 J/m²) of selected strains. (A) Vegetative cells of B. pumilus SAFR-032 that survived UV-Space were designated 55 series (2 strains) and 56 series (5 strains). Strains that survived UV-Mars were denoted as 183 series (5 strains). One parental ISS control strain kept on the ground and never flown was used for comparison. (B) Vegetative cells of B. pumilus SAFR-032 that survived Dark-Space were designated 40 series (5 strains). Strains that survived Dark-Mars were denoted as 167 series (10 strains) and 168 series (6 strains). (C) Quantitative measurement of UV₂₅₄ resistance of selected B. pumilus cells. Cells with the following designations were used to measure UV resistance by exposure to UV₂₅₄ at a dosage from 0 to 900 J/m²: Control (kept on the ground and never flown to space), UV-Space (56T-2), UV-Mars (183T-1), Dark-Space (40T-5), and Dark-Mars (168T-5). Measurements of two dilution series were plated and averaged.