Odor-free chassis does not produce the fecal odor indole To verify our selection of
E. coli strain YYC912 as an odor-free chassis, we analyzed cultures of each strain for indole production using gas chromatography.
E. coli strain YYC912 had no detectable indole (A) whereas
E. coli strain TOP10 had high levels of indole (B). The retention time of the indole peak from
E. coli strain TOP10 is identical to that of the pure indole standard (C).