HPLC analysis of the production of TCA and related analogs from wild-type M. chalcea and recombinant strain TL3003. I, authentic standard; II, wild type; III, TL3003 (ΔtacA1, -A2, -A4, and -A5). The solid triangles indicate TCA. The numbers 1 to 6 indicate TCA analogs 1 to 6.