Synergistic Degradation Of Pyrene Bypseudomonas Aeruginosapa06 Andachromobactersp. Ac15 With Sodium Citrate As The Co-Metabolic Carbon Source

Two pyrene-degrading strains,Pseudomonas aeruginosaPA06 andAchromobactersp. AC15 were co-incubated in equal proportions as a microbiological consortium and could enhance the degradation of pyrene. The enzymatic activities of the catechol 1,2-dioxygenase (C12O) and 2,3-dioxygenase activities (C23O) were produced complementary expression byP. aeruginosaPA06 andAchromobactersp. AC15, respectively. Meanwhile, results showed that pyrene degradation was sufficiently promoted in the presence of sodium citrate as a co-metabolic carbon source, likely a result of enhanced biomass and biosurfactant production. The optimized dosage and ideal initial pHs were 1.4 g L(-1)and 5.5, respectively. We also analyzed the rate constant of pyrene degradation, cell growth, and enzyme activity. Results show thatP. aeruginosaPA06 had a better effect thanAchromobactersp. AC15 in bacterial growth. However, the C23O or C12O activity produced byAchromobactersp. AC15 continued at a similar or even faster than that ofP. aeruginosaPA06. The mixed bacteria had a better effect than any single bacteria, suggesting the strains worked synergistically to enhance the degradation efficiency. In the co-metabolism system of 600 mg/L pyrene and 1.4 g/L sodium citrate, pyrene degradation reached 74.6%, was 1.57 times, 2.06 times, and 3.89 times that of the mix-culture strains, single PA06 and single AC15 without sodium citrate, respectively. Overall, these findings are valuable as a potential tool for the bioremediation of high-molecular-weight PAHs.