Bio-augmentation effect of Achromobacter sp. strain JWJ-09 on quinoline and real coking wastewater under methanol co-metabolism

Abstract

Quinoline is a refractory substance found in industrial wastewater. The biodegradation of quinoline by the novel Achromobacter sp. strain JWJ-09 in an inorganic salt medium was investigated over a wide range of initial quinoline concentrations (100–700 mg·l−1), with methanol as the co-metabolic substrate. Nearly complete degradation of 300 mg·l−1 quinoline was achieved at 32 h accompanied by bacterial growth when 100 mg·l−1 methanol was added to the quinoline-containing solution. Strain JWJ-09 showed strong quinoline degradability. Quinoline degradation was demonstrated through the 8-hydroxycoumarin metabolic pathway. The cell growth kinetics was evaluated by using the Haldane model. Both the maximum specific growth rate (μmax = 0.67 h−1) and the substrate inhibition coefficient (Ki = 795.02 mg·l−1) were higher than those observed by other researchers. This indicated that strain JWJ-09 grew faster and could tolerate higher quinoline concentrations. Furthermore, under methanol co-metabolizing, strain JWJ-09 together with the activated sludge was used to treat the real coking wastewater, quinolone could be degraded in only 24 h and TOC (total organic carbon) removal efficiency reached 90.75 %. High-throughput sequencing analysis showed that the biological enhancement effect of strain JWJ-09 and methanol was obvious, which could increase the abundance of the dominant bacteria in the activated sludge. The results confirmed that strain JWJ-09 could be used to treat the quinoline-containing wastewater.