Bio-Augmentation of Cupriavidus sp. CY-1 into 2,4-D Contaminated Soil: Microbial Community Analysis by Culture Dependent and Independent Techniques

PLoS One. 2015 Dec 28;10(12):e0145057. doi: 10.1371/journal.pone.0145057. eCollection 2015.

Abstract

In the present study, a 2,4-dichlorophenoxyacetic acid (2,4-D) degrading bacterial strain CY-1 was isolated from the forest soil. Based on physiological, biochemical and 16S rRNA gene sequence analysis it was identified as Cupriavidus sp. CY-1. Further 2,4-D degradation experiments at different concentrations (200 to 800 mg l(-1)) were carried out using CY-1. Effect of NaCl and KNO3 on 2,4-D degradation was also evaluated. Degradation of 2,4-D and the metabolites produced during degradation process were analyzed using high pressure liquid chromatography (HPLC) and GC-MS respectively. The amount of chloride ions produced during the 2,4-D degradation were analyzed by Ion chromatography (IC) and it is stoichiometric with 2,4-D dechlorination. Furthermore two different types of soils collected from two different sources were used for 2,4-D degradation studies. The isolated strain CY-1 was bio-augmented into 2,4-D contaminated soils to analyze its degradation ability. Culture independent methods like denaturing gradient gel electrophoresis (DGGE) and terminal restriction fragment length polymorphism (T-RFLP), and culture dependent methods like colony forming units (CFU) and most probable number (MPN) were used to analyze the survivability of strain CY-1 in contaminated soil. Results of T-RFLP were coincident with the DGGE analysis. From the DGGE, T-RFLP, MPN and HPLC results it was concluded that strain CY-1 effectively degraded 2,4-D without disturbing the ecosystem of soil indigenous microorganisms.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 2,4-Dichlorophenoxyacetic Acid / metabolism*
  • Biodegradation, Environmental*
  • Biodiversity
  • Chromatography, High Pressure Liquid
  • Cupriavidus / genetics
  • Cupriavidus / isolation & purification*
  • Cupriavidus / metabolism*
  • DNA, Bacterial / genetics
  • Denaturing Gradient Gel Electrophoresis
  • Ecosystem
  • Gas Chromatography-Mass Spectrometry
  • Herbicides / metabolism*
  • Nitrates / chemistry
  • Polymorphism, Restriction Fragment Length
  • Potassium Compounds / chemistry
  • RNA, Ribosomal, 16S / genetics
  • Sodium Chloride / chemistry
  • Soil / chemistry
  • Soil Microbiology
  • Soil Pollutants / metabolism*

Substances

  • DNA, Bacterial
  • Herbicides
  • Nitrates
  • Potassium Compounds
  • RNA, Ribosomal, 16S
  • Soil
  • Soil Pollutants
  • 2,4-Dichlorophenoxyacetic Acid
  • Sodium Chloride
  • potassium nitrate

Grants and funding

This work was supported by a Grant-in-Aid for Scientific Research (No. 26340067) from the Ministry of Education, Culture, Sports, Science and Technology of Japan and Research fund of Muroran Institute Technology, Japan.