organism: hydrocarbon metagenome
description: In the current study, we evaluated the effect of anaerobic storage (90% N2, 10% CO2) on the microbial population from this same active tailings pond. DNA was isolated from selected depths from tailings samples stored under anaerobic conditions for 1.5 years. Analysis of 16S genes by pyrosequencing indicated an increase in fermentative bacteria capable of reducing nitrate (Delftia, Acidovorax, Thauera, Pseudomonas) at most of the depths along with a high abundance of methanogens (Methanosaeta, Methanobacterium, Methanolobus) at a depth of 18 m below the surface. No syntrophs or SRB were detected. UniFrac clustering analysis indicated this community profile to be similar to that of another tailings pond that no longer receives input of fresh tailings. The results indicate that tailings pond microbial communities are dynamic and change rapidly when input of fresh tailings and/or gypsum are stopped.