2-D PAGE images of samples treated with pyrene or pyrene-4,5-dione at a pI range of 4 to 7. The molecular mass marker is 14 to 97 kDa. (A) Mycobacterium sp. strain KMS with no PAH added; (B) with pyrene added; (C) with pyrene-4,5-dione added. ○, proteins induced at a more than twofold-higher level than for the control; □, newly detected proteins. P1 to P14, Q1, and Q2 were selected for further identification.