Tellurite resistance and reduction by a Paenibacillus sp. isolated from heavy metal-contaminated sediment.

A gram-positive bacterium (designated as strain TeW) that is highly resistant to tellurite was isolated from sediment. The bacterium can grow in the presence of up to 2,000 micromol/L of potassium tellurite (K2TeO3). Reduction of K2TeO3 to tellurium was indicated by the blackening of the growth medium. No lag in growth was observed when cells unexposed to tellurite were transferred to the growth medium containing K2TeO3, indicating that resistance to tellurite was not inducible. Up to 50 and 90% of the metalloid oxyanion tellurite (TeO(3)(2-)) was removed from the medium by strain TeW during growth in nonstatic (shaking) and static (without shaking) conditions, respectively. The bacterium was identified as a Paenibacillus sp. according to its morphology, physiology, and 16S rDNA sequence homology.