Fig. 2.

Growth of 100 isolates from Siberian permafrost samples on TSBYS plates. Isolates are from permafrost sample 5 (colonies 1–25), 4 (colonies 26–50), 8 (colonies 51–75), and 9 (colonies 76–100). (A–C) All isolates were cultivated for 30 d at 0 °C under the following conditions: (A) Earth atmosphere and pressure. (B) Simulated Mars atmosphere, Earth pressure. (C) Simulated Mars atmosphere and pressure. Colony 43 from permafrost sample 4 was designated strain WN1359. (D) Same plate as in C, but after 1 additional day of incubation on the laboratory bench (i.e., at room temperature, Earth atmospheric composition and pressure).