A new method for rapid construction of a Pseudomonas sp. HF-1 bioaugmented system: Accelerating acylated homoserine lactones secretion by pH regulation

• pH control efficiently regulated release of autoinducers.
• Auto-inducer induced EPS benefited strain HF-1 colonization.
• pH regulation of quorum sensing facilitated sludge granulation.
• pH regulation of quorum sensing is a feasible method for HF-1 bioaugmentation.

Pseudomonas sp. HF-1 bioaugmented systems were operated to treat tobacco wastewater under pH 5.5 for three cycles and pH 8.0 for the rest, which was suitable for HF-1 biofilm formation. The results showed that, under pH control, the contents of 3-oxo-C6-HSL, C6-HSL and 3-oxo-C8-HSL were significantly higher than HF-1 thresholds for biofilm formation. Compared with non-pH controlled reactors, HF-1 showed greater colonization in pH controlled reactors, primarily owing to the high extracellular polymeric substances secretion induced by quorum sensing. Accordingly, high indigenous community activity and granular sludge were observed. Sludge granulation occurred from the seventh cycle, and the average diameter was greater than 400 μm. These systems were also highly efficient with nearly 100% nicotine degradation and 60% total organic carbon removal. Overall, the results indicate that pH regulation is a new and feasible method for acceleration of releasing of auto-inducers, which is beneficial to construction of HF-1 bioaugmented systems.