G. Southam et Tj. Beveridge, EXAMINATION OF LIPOPOLYSACCHARIDE (O-ANTIGEN) POPULATIONS OF THIOBACILLUS-FERROOXIDANS FROM 2 MINE TAILINGS, Applied and environmental microbiology, 59(5), 1993, pp. 1283-1288
Net acid-generating capacities of 39.74 kg of H2SO4 per ton (ca. 0.05
kg/kg) (pH 2.68) for the Lemoine copper mine tailings (closed ca. 8 ye
ars ago; located 40 km west of Chibougamau, Quebec, Canada) and 16.07
kg of H2SO4 per ton (ca. 0.02 kg/kg) (pH 3.01) for the Copper Rand tai
lings (in current use and 50 km distant [east] from those of Lemoine)
demonstrate that these sulfide tailings can support populations of aci
dophilic thiobacilli. Oxidized regions in both tailings environments w
ere readily visible, were extremely acidic (Lemoine, pH 2.36; Copper R
and, pH 3.07), and provided natural isolates for our study. A 10% (wt/
vol) oxalic acid treatment, which solubilizes both ferric sulfate and
ferric hydroxide precipitates (B. Ramsay, J. Ramsay, M. deTremblay, an
d C. Chavarie, Geomicrobiol. J. 6:171-177, 1988), enabled the recovery
of intact bacterial cells from the tailings material and from liquid
synthetic medium for lipopolysaccharide analysis. No viable cells coul
d be cultured after this oxalic acid treatment. Sodium dodecyl sulfate
-polyacrylamide gel electrophoretic profiles of lipopolysaccharides ex
tracted from the Lemoine tailings were complex, indicating a heterogen
eous population of Thiobacillus ferrooxidans. Six T. ferrooxidans subs
pecies as identified by lipopolysaccharide analysis (i.e., lipopolysac
charide chemotypes) were eventually isolated from a total of 112 cultu
res from the Lemoine tailings. Using the same isolate and lipopolysacc
haride typing techniques, we identified only a single lipopolysacchari
de chemotype from 20 cultures of T. ferrooxidans isolated from the Cop
per Rand tailings. This homogeneity of lipopolysaccharide chemotype wa
s much different from what was found for the older Lemoine tailings an
d may reflect a progressive lipopolysaccharide heterogeneity of Thioba
cillus isolates as tailings leach and age.