Fig. 3

Functional verification of the 4-chlorophenol degradation pathway. (a) the proposed 4-chlorophenol degradation pathway. I, 4-chlorophenol; II, 4-chlorocatechol; III, 4-chloromuconic acid; IV, (R)-2-(2-chloro-5-oxo-2,5-dihydrofuran-2-yl) acetic acid; V, 2-(5-oxo-2,5-dihydrofuran-2-yl) acetic acid; VI, (E)-2-(5-oxofuran-2(5 H)-ylidene) acetic acid. (b) the degradation of phenol, 4-chlorophenol, 2,3-dichlorophenol by recombinant strain with PheA1A2. (c) the degradation of phenol, 4-chlorophenol, 2,3-dichlorophenol by recombinant strain with TfdB. (d) the degradation ratio of 4-chlorophenol by different recombinant E. coli BL21 strains. pheA1A2, E. coli BL21 harboring pET28a-pheA1A2; pheA + catA, E. coli BL21 harboring pET28a-pheA1A2 and pYB1s-catA; pheA1A2 + catABC, E. coli BL21 harboring pET28a-pheA1A2 and pYB1s-catABC; the cell growth of different strains were also indicated; (e) HPLC data and mass spectra of the identified metabolic products. All the experiments were performed in triplicate and data shown are mean ± SD. Some derivations were too small to be shown