BACTERIAL COMMUNITY CHARACTERIZATION OF AN ABANDONED SEMI-ARID LEAD-ZINC MINE TAILINGS SITE

Department of Soil, Water and Environmental Science, The University of Arizona, 429 Shantz Building #38, Tucson, Arizona 85721

^* To whom correspondence should be addressed. Email: rmaier{at}ag.arizona.edu.

	Abstract

Bacterial diversity in mine tailings microbial communities has not been thoroughly investigated despite the correlations that have been observed between relative microbial diversity and the success of revegetation efforts at tailings sites. This study employed phylogenetic analysis of 16S rRNA genes to compare the bacterial communities present in highly disturbed extremely (pH 2.7) and moderately (pH 5.7) acidic lead-zinc mine tailings samples from a semi-arid environment with a vegetated off-site control sample (pH 8). Phylotype richness in these communities decreased from 42 in the off-site control to 24 in the moderately acidic and 8 in the extremely acidic tailings samples. The clones in the extremely acidic tailings sample were most closely related to acidophiles, none of which were detected in the off-site control sample. The comparison generated by this study between bacteria present in extremely and moderately acidic tailings communities with those in an off-site control soil, provides a reference point from which to evaluate the successful restoration of mine tailings disposal sites by phytostabilization.