a Pathway of a penta-BDE mixture mediated by D. mccartyi strains CG1, CG4 and 11a5; b Pathway of hepta-BDE 183 carried by D. mccartyi 11a5. Removal of ortho-, meta-, and para- bromines are indicated with green, blue, and purple lines, respectively. Red and black color font indicate PBDE congeners used as substrates and those formed as metabolites, respectively.