Metalloid resistance, utilization of organic substrates, variation in pH, level of aeration, and protein and ATP production were all examined in the presence of K2TeO3. Resistance was confirmed in RO liquid medium with varying concentrations of K2TeO3 (100, 250, 500, 750, 1000, and 1500 µg/mL). Growth was monitored spectrophotometrically at A950, an established method for estimating growth and reduction in the presence of tellurite, over 96 h . All growth for subsequent experiments was monitored at A950 with 500 µg/mL (strains E1, E4(1), E5, and KR99) or 100 µg/mL (RB3 and RB 16-17) K2TeO3 in liquid culture over 96 h, unless otherwise described. The effect of carbon sources on growth and reduction was investigated by transfer of actively growing cells to MS liquid medium, pH 7.8, with K2TeO3 containing one of: acetate, butyrate, citrate, ethanol, fructose, glucose, glutamate, L-glutamine, lactate, malate, pyruvate, or succinate at either 1.5 or 3.0 g/L. The solubility of K2TeO3, and therefore the availability in solution, changes with pH  that is why the effect of pH on resistance and reduction was tested. As the addition of K2TeO3 to the growth medium caused the formation of precipitates under acidic conditions and strains could not grow beyond pH 9.5, only pH range 7.0 to 9.0 was considered. Liquid medium was adjusted with 0.5 N NaOH to the desired pH. The role of oxygenation was analyzed in an incubator shaker set to 100 (low), 200 (typical) or 300 (high) rpm. Once optimal conditions were established, strains were grown at those parameters with 500 or 1000 µg/mL (strains E1, E4(1), E5, and KR99) or 100 or 500 µg/mL (RB3 and RB 16-17) K2TeO3. To observe the effect of tellurite on cellular protein and ATP levels, measurements were taken in its presence and absence over 48 h. Protein was assayed by the Bradford method  and ATP was monitored with an ATP Bioluminescence Kit from Sigma-Aldrich, following extraction from samples with perchloric acid .