Antarctic Soil and Viable Microbiota After Long-Term Storage at Constant −20 °C

Abstract

Soil samples taken from three locations in east continental Antarctica were airtight sealed and stored at −20 °C for over a decade before being analyzed. Interestingly, some microbial strains survived the long-term storage while isolated from the habitat. Soil organic and elemental contents were also analyzed and the results varied significantly, although Fe was the predominant element in all samples. Apostrophe Island presented particularly higher organic matter content, and higher levels of Co, Cr, Ni, Sr, Cu and P, as well as As, which was detected in significant quantities. The arsenic soil samples presented viable Pseudomonas arsenicoxydans, and other preserved and recovered strains included Pseudomonas graminis, Sporosarcina aquimarina, and Geomyces pannorum, extremophiles which we can now consider beyond any reasonable doubt to be facultative psychrophiles which can form dormant states.