Temporal profiling of the microbial community from the lime-treated abandoned mine tailing ?Relave Viejo? in Neuquén, Argentina

HAROLD NUÑEZ; ALEJANDRA GIAVENO; JOSÉ RICARDO ULLOA; ANA MOYA-BELTRÁN; FRANCISCO ISSOTTA; RAQUEL QUATRIN

Montreal

Simposio; 16th International Symposium on Microbial Ecology; 2016

ISME Society

p { margin-bottom: 0.25cm; direction: ltr; color: rgb(0, 0, 10); line-height: 120%; text-align: left; }p.western { font-family: "Cambria",serif; font-size: 12pt; }p.cjk { font-family: "ＭＳ 明朝"; font-size: 12pt; }p.ctl { font-family: "Arial"; font-size: 12pt; }a:link { color: rgb(0, 0, 255); }Minetailings are a serious threat to the environment and public health.Water-exposed sulfur-bearing ore tailings can be the source ofmetal-loaded acidic waters that drain to the environment withdeleterious consequences.Acidificationis further accelerated bytheactivity of iron and sulfur oxidizing bacteria inhabiting the ores.Although a number of mitigation strategies exist, lime neutralizationremains by far the most popular treatment method. However, thepolluting potential of naturally occurring microbes associated tomost mine tailings remains largely unexplored and routinesurveillance programs still need to be developed. Thus, it is key tobetter understand the structural and temporal dynamics of the nativebacterial communities within both untreated and lime-treated minetailings.Inthis work, we have applied a 16S rRNA gene-targeted metagenomicapproach to profile the microbial community of an abandoned minetailing from Neuquén (Argentina) and to asses the effects of limetreatment on the microbial population, over a 3-year period. In spiteof achieving post-treatment pH control (~ 7), after 3 years the siteis characterized by high levels of heavy metals and a communitydominated by extreme acidophiles. Our data show that the overallmicrobial diversity estimates and relative abundances of the dominantgenera, Acidithiobacillus,Leptospirillum,Acididiphillumdecreased in time, while the richness steadily increased. Theseresults suggest that lime?based neutralization had transient andmild effects, and that routine surveillance of the microbialpopulations is an absolute requirement to improve management ofabandoned mine tailings.