Bioaugmentation of activated sludge with Acinetobacter sp. TW enhances nicotine degradation in a synthetic tobacco wastewater treatment system

Bioaugmentation (BA) using Acinetobacter sp. TW with high nicotine-degrading efficiency was applied in a bioreactor receiving a load of COD (3200 ± 50 mg/L) and nicotine (1.0 ± 0.1 g/L). The results showed that because of the colonization of strain TW, the COD removal was stable at 80-90%, while nicotine removal reached 98% in the BA system. Furthermore, according to PCR-DGGE fingerprinting, compared with the originally activated sludge, more bacteria existed in the BA systems while some bacteria disappeared from the non-BA system. In terms of the quorum sensing, short chain AHLs increased to assist colonization of strain TW, and long chain AHLs were secreted and helped to resist the nicotine toxicity. Compared with the non-BA system, the amounts of ROS, protein carbonyls and 8-OHdG were significant lower in the BA systems, which suggested that strain TW played an important role in eliminating the nicotine toxicity from the bioreactors.