Indigo production from indole by microbial communities.
A. Indigo production by three activated sludge systems. B. Indole consumption by three activated sludge systems. G1, non-augmented AS; G2, AS plus Comamonas sp. MQ; G3, AS plus E. colinagAc. The concentrations of indole and indigo were measured by HPLC at the end of SBR operation cycle.