Biodegradation of di-n-butyl phthalate by bacterial consortium LV-1 enriched from river sludge

PLoS One. 2017 May 25;12(5):e0178213. doi: 10.1371/journal.pone.0178213. eCollection 2017.

Abstract

A stable bacterial consortium (LV-1) capable of degrading di-n-butyl phthalate (DBP) was enriched from river sludge. Community analysis revealed that the main families of LV-1 are Brucellaceae (62.78%) and Sinobacteraceae (14.83%), and the main genera of LV-1 are Brucella spp. (62.78%) and Sinobacter spp. (14.83%). The optimal pH and temperature for LV-1 to degrade DBP were pH 6.0 and 30°C, respectively. Inoculum size influenced the degradation ratio when the incubation time was < 24 h. The initial concentration of DBP also influenced the degradation rates of DBP by LV-1, and the degradation rates ranged from 69.0-775.0 mg/l/d in the first 24 h. Degradation of DBP was best fitted by first-order kinetics when the initial concentration was < 300 mg/l. In addition, Cd2+, Cr6+, and Zn2+ inhibited DBP degradation by LV-1 at all considered concentrations, but low concentrations of Pb2+, Cu2+, and Mn2+ enhanced DBP degradation. The main intermediates (mono-ethyl phthalate [MEP], mono-butyl phthalate [MBP], and phthalic acid [PA]) were identified in the DBP degradation process, thus a new biochemical pathway of DBP degradation is proposed. Furthermore, LV-1 also degraded other phthalates with shorter ester chains (DMP, DEP, and PA).

MeSH terms

  • Biodegradation, Environmental*
  • Brucellaceae / metabolism
  • Dibutyl Phthalate / metabolism*
  • Environmental Pollutants / metabolism*
  • Geologic Sediments / microbiology
  • Sewage / chemistry*
  • Sewage / microbiology
  • Soil Microbiology

Substances

  • Environmental Pollutants
  • Sewage
  • Dibutyl Phthalate

Grants and funding

This work was supported by a grant from the National Natural Science Foundation of China (41430637); Program for Innovative Research Team (in Science and Technology) in University of Henan Province (16IRTSTHN012); Science and technology development project of Henan Province (152102310297); Opening Foundation of the Chinese National Engineering Research Center for Control and Treatment of Heavy Metal Pollution, Changsha, 410083, China (No. 2015CNERC-CTHMP-).