Enhanced Biodegradation of Anthracene by Multi-Substrate Progressive Domestication of a Mixed Microbial Consortium With Pseudomonas_Aeruginosa DM3

Abstract

The degradation of polycyclic aromatic hydrocarbons has attracted much attention. Based on toluene-catechol-anthracene multi-substrate progressive domestication, a mixed microbial consortium with synergistic metabolic activity was screened from the activated sludge of coking wastewater. High-throughput sequencing showed that the consortium was dominated by Flavobacteriia at the class level, with the proportion increasing from 8.88% to 56.41% after domestication, and that Myroides and Brevundimonas dominated at the genus level, increasing from less than 1% to 55.53% and 12.28%, respectively. Under temperature conditions of 30 °C, a pH of 7, and an initial anthracene concentration of 40 mg L-1, the degradation ratio reached 85.7% just 16 days after inoculation. Degradation ratio of Anthracene (40 mg L-1) via the consortium plus an indigenous strain Pseudomonas_aeruginosa DM3 on the sixth day (83%) equated to that in the control group without DM3 on the 12th day. The first-order rate constant (k=0.240 and 0.159 d-1) was calculated for the anthracene degradation within 10 days, with a corresponding half-life by the consortium of 2.9 days with DM3 and 4.4 days without DM3. The metabolites 1-naphthol, dibutyl phthalate, and 1,2-benzene dicarboxylic acid, mono (2-ethylhexyl) ester were presented in the reaction, inferring the metabolic pathway of phthalic acid. Our work revealed that inoculating the mixed microbial consortium with indigenous Pseudomonas aeruginosa DM3 has the potential for removing polycyclic aromatic hydrocarbons.