Subzero Soils with Metabolic Microbes

By Grabiel Valdez

Microbes have proven to show metabolic activity between 0-20oC and scientists theorize further activity at lower temperatures in permafrost environments. The bacterial genome replication proved to be more productive at a narrow range of temperatures below -6oC . Different microbes showed to prefer different ranges of temperatures which proved vital in understanding the present polar microbial community as temperatures begin to change and certain microbes become dormant in using frozen organic carbon. Further study is needed to support these findings on their metabolic activity in frozen soils; therefore, the notion that life on planets with frozen terrains is possible.  

Figure from Tuorto et al. 2013 showing segregation of ¹²C and ¹³C-DNA in a cesium gradient allow the identification of present microbes (blue profile) and active microbes (red profile) of the bacterial community from the samples taken. There was the use of the experimental use of 13c-acetate and the control of ¹²C -acetate to indicate ¹³C -DNA synthesis at subzero temperatures. The 13c-carrier bands showed no reaction to the control of ¹²C -acetate however the experimental ¹³C -acetate showed enrichment in the ¹³C -carrier bands correlated to the ¹²C top-bands counterpart to show activity of the microbes and rule out contamination.

Original Article: Tuorto S, Darias P, McGuinness L, Panikov N, Zhang T, Häggblom M and Kerkhof L (2013). Bacterial genome replication at subzero temperatures in permafrost. ISME J doi: 10.1038/ismej.2013.140