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

During an Antarctic expedition that took place in December 2010-January 2011 in the East Antarctic coastal region, soil samples were collected in aseptic conditions and stored for over a decade in freezers at -20 °C. Due to the shortly afterward passing of the Antarctic researcher in charge, Teodor Negoiță, the samples remained unintentionally frozen for a long period and were made available for research 13 years later. A chemical analysis of soil as well as screening for viable microbial presence was performed; soil analysis was conducted via inductively coupled plasma atomic emission spectroscopy (ICP-AES) and Fourier-transform infrared spectroscopy coupled with attenuated total reflection (FTIR-ATR). The presence of aerobic and facultative aerobic microbiotas was evaluated through a Biolog Ecoplates assay, and isolated strains were 16S sequenced for final taxonomic identification. The results obtained new insights into Antarctic soil characteristics from both chemical and microbiological aspects, even after over a decade of conservation.