Our understanding of AAPs in general  and their interaction with tellurite in particular is still poor with many questions remaining. Obviously, the composition of the growth medium influences the level of resistance. Previous work has shown that in complex medium resistance to tellurite can be increased . In this study we found a similar trend, with E1, E4(1), RB3, and RB 16-17 favoring RO medium. However, E5 and KR99 preferred a defined medium containing glutamate, pyruvate, and malate. We do not know why such a difference was seen. Perhaps these carbon sources are involved with, or can be directly utilized by, the TCA cycle , providing an advantage in energy generation under the stress of K2TeO3 pressure. Therefore, with conditions conducive to easier growth, the negative impact of tellurite can be overcome. It is also likely that these compounds are acting similar to how acetate does in R. capsulatus, competing with tellurite for cellular entry, thereby increasing resistance .