Fig. 6

Proposed substrate cross-feeding between BPA-degrading Sphingomonas sp. and non-degrading Pseudomonas sp. or Pusillimonas sp. A simplified pathway presentation of major substrates found in the bulk community environment (a); Sphingomonas sp. in the community transformed BPA to 1-BP, 4-DM, and 2-BP during the initial stage of biodegradation (b); then further transformed 1-BP and 4-DM to either 4-HBD or 4-HAP; 4-HBD was quickly converted to 4-HBZ; both of 4-HBD and 4-HBZ were used by Pseudomonas sp. and Pusillimonas sp. (c); and Sphingomonas started consuming 2-BP after 4-HBD/4-HBZ depletion, while Pseudomonas coverts 4-HAP to 4-HPAT and then HQN (d); HQN was degraded by the Pusillimonas. Lines with green arrow suggests the interaction was confirmed by experiment by using isolates