Fungal pellets immobilized bacterial bioreactor for efficient nitrate removal at low C/N wastewater

Bioresour Technol. 2021 Jul:332:125113. doi: 10.1016/j.biortech.2021.125113. Epub 2021 Apr 7.

Abstract

In this study, fungal pellets immobilized denitrifying Pseudomonas stutzeri sp. GF3 was cultivated to establish a bioreactor. The denitrification effect of fixed bacteria with fungal pellets was tested by response surface methodology (RSM). Analysis of the bioreactor showed that the denitrification efficiency reached 100% under the optimal conditions and the denitrification efficiency of the actual wastewater treatment in the stable phase reached 95.91%. Moreover, the organic matter and functional groups in the bioreactor under different C/N conditions were analyzed by fluorescence excitation-emission matrix (EEM) spectra and Fourier transform infrared spectroscopy (FTIR), which revealed that metabolic activities of denitrifying bacteria were enhanced with the increase of C/N. The morphology and structure of bacteria immobilized by fungal pellets explored by scanning electron microscope (SEM) showed the filamentous porous fungal pellets loaded with bacteria. Community structure analysis by high-throughput sequencing demonstrated that strain GF3 might was the dominant strain in bioreactor.

Keywords: Denitrification; Fungal pellet; High throughput sequencing; Immobilized bioreactor; Low C/N.

MeSH terms

  • Bacteria
  • Bioreactors
  • Denitrification
  • Nitrates*
  • Nitrogen
  • Wastewater*

Substances

  • Nitrates
  • Waste Water
  • Nitrogen