Bioremediation of PAEs-contaminated saline soil: The application of a marine bacterial strain isolated from mangrove sediment

Phthalic acid esters (PAEs) are known as the most widely used plasticizer as well as one of the ubiquitously distributed emerging pollutants. Biodegradation and bioremediation via application of PAEs-degrading microbes is promising. In this study, a novel marine microbe, Gordonia hongkongensis RL-LY01, was isolated from mangrove sediment showing high di-(2-ethylhexyl) phthalate (DEHP) degradation capacity. Strain RL-LY01 could degrade a wide range of PAEs and the degradation kinetics of DEHP followed the first-order decay model. Meanwhile, good environmental adaptability, preference to alkaline conditions and good tolerance to salinity and metal ions was shown. Further, metabolic pathway of DEHP in strain RL-LY01 was proposed, with di- ethyl phthalate, phthalic acid, benzoic acid and catechol as intermediates. Additionally, one known mono-alkyl phthalate hydrolase gene (mehpH) was identified. Finally, the excellent performance during bioremediation of artificial DEHP-contaminated saline soil and sediment indicated strain RL-LY01 employs great application po- tential for the bioremediation of PAE-contaminated environments.

Automated summary

In this study, a novel marine microbe, Gordonia hongkongensis RL-LY01, was isolated from mangrove sediment and showed high di-(2-ethylhexyl) phthalate (DEHP) degradation capacity. The strain could degrade a wide range of phthalic acid esters (PAEs) and exhibited good environmental adaptability. The metabolic pathway of DEHP in strain RL-LY01 was proposed, and a known mono-alkyl phthalate hydrolase gene was identified. Additionally, the strain showed excellent performance during bioremediation of DEHP-contaminated environments.