A Novel and Native Microcystin-Degrading Bacterium of Sphingopyxis sp. Isolated from Lake Taihu

Int J Environ Res Public Health. 2017 Oct 6;14(10):1187. doi: 10.3390/ijerph14101187.


A native, highly efficient microcystin-LR (MC-LR)-degrading bacterium named a7 was isolated from Lake Taihu and identified as Sphingopyxis sp. by 16S rDNA sequence analysis. The strain a7 could totally degrade MC-LR at a rate of 3.33 mg/(L•h), as detected by high-performance liquid chromatography (HPLC). The mlrA, mlrC, and mlrD genes were detected in the strain a7 by sequence analysis. Tetrapeptide and Adda-which are the middle metabolites of MC-LR-were analyzed via liquid chromatography time-of-flight mass spectrometry (LC-TOF-MS) during degradation. These metabolites were degraded completely, which suggested that the native Sphingopyxis sp. a7 was highly efficient in MC-LR degradation under bench conditions. Thus, strain a7 exhibited a significant potential application for bioremediation in water bodies contaminated by MC-LR produced by harmful cyanobacterial blooms.

Keywords: Lake Taihu; Sphingopyxis sp.; biodegradation; microcystin.

MeSH terms

  • Biodegradation, Environmental
  • China
  • Chromatography, High Pressure Liquid
  • DNA, Bacterial / genetics
  • DNA, Ribosomal / genetics
  • Harmful Algal Bloom
  • Lakes / microbiology*
  • Marine Toxins
  • Mass Spectrometry
  • Microcystins / metabolism*
  • Sphingomonadaceae / genetics
  • Sphingomonadaceae / isolation & purification
  • Sphingomonadaceae / metabolism*
  • Water Pollutants, Chemical / metabolism*


  • DNA, Bacterial
  • DNA, Ribosomal
  • Marine Toxins
  • Microcystins
  • Water Pollutants, Chemical
  • cyanoginosin LR