Interestingly, strains E1, E5, KR99, RB3, and RB 16-17 appear to possess similar strategies for tellurite reduction, in both expression and location. While this may imply they are alike, the ability of each strain to reduce and resist tellurite is different , which suggests they may actually have different sets of physiological reactions to interact with the oxyanion. Also, one can see reduction profiles in strains RB3 and RB 16-17 differ from the others, with whole cells having a higher rate than fractions even though activity is present in membranes. It is possible more than one mechanism is employed for reducing tellurite and/or some other cellular component is required for maximal effectiveness. Further research is needed to elucidate the exact approach utilized here. Strain E4(1) was the only one requiring a fully functional intact cell, as well as de novo protein preparations, for reduction. Other studied species capable of tellurite reduction/resistance at very high levels have been reported to possess a similar requirement , and may share a comparable physiology. Possibly, E4(1) has an operational membrane electron transport system similar to Shewanella oneidensis MR-1 developed for Fe(III), Mn(IV), and V(V) reduction .