Phenotypic characteristics of Thiobacillus ferrooxidans strains

Phenotypic polymorphism of Thiobacillus ferrooxidans strains isolated from various ecological niches was studied. The strains differed both in rates of growth and oxidation of Fe(2+), S(0), FeS(2), and sulfide minerals contained in concentrate. Each strain, irrespective of its original environment, required a period of adaptation to a new substrate. Strains TFN-d, TFBk, TFO, and TFL-2, isolated from ores and concentrates rich in oxidizable substrates, showed an equal adaptation rate (five culture transfers) but differed in their adaptation efficiency. Strain TFV-1, isolated from low-grade ore and showing the lowest rates of growth and oxidation of all the substrates, required five culture transfers to adapt to S(0) and FeS(2) and seven culture transfers to adapt to the concentrate. It is concluded that the phenotypic properties of the strains correlate with their genotypic polymorphism and the environmental conditions under which their microevolution took place.