Efficient biodegradation of acetoacetanilide in hypersaline wastewater with a synthetic halotolerant bacterial consortium

The high concentrations of salt and refractory toxic organics in industrial wastewater seriously restrict biological treatment efficiency and functional stability. However, how to construct a salt-tolerant biocatalytic community and realize the decarbonization coupled with detoxification toward green bio-enhanced treatment, has yet to be well elucidated. Here, acetoacetanilide (AAA), an important intermediate for many dyes and medicine synthesis, was used as the model amide pollutant to elucidate the directional enrichment of halotolerant degradative communities and the corresponding bacterial interaction mechanism. Combining microbial community composition and molecular ecological network analyses as well as the biodegradation efficiencies of AAA and its hydrolysis product aniline (AN) of pure strains, the core degradative bacteria were identified during the hy-persaline AAA degradation process. A synthetic bacterial consortium composed of Paenarthrobacter, Rhizobium, Rhodococcus, Delftia and Nitratireductor was constructed based on the top-down strategy to treat AAA wastewater with different water quality characteristics. The synthetic halotolerant consortium showed promising treatment ability toward the simulated AAA wastewater (AAA 100-500 mg/L, 1-5% salinity) and actual AAA mother li-quor. Additionally, the comprehensive toxicity of AAA mother liquor significantly reduced after biological treatment. This study provides a green biological approach for the treatment of hypersaline and high concen-tration of organics wastewater.

Automated summary

This study investigates the construction of a salt-tolerant biocatalytic community for the efficient treatment of industrial wastewater containing high concentrations of salt and toxic organics. A synthetic bacterial consortium was constructed and showed promising treatment ability for the simulated wastewater. The study provides a green biological approach for the treatment of hypersaline and high concentration of organics wastewater.