Simultaneous cobalt(III)-histidine reduction and aerobic denitrification by Paracoccus versutus LYM

Bioresour Technol. 2020 Aug:310:123404. doi: 10.1016/j.biortech.2020.123404. Epub 2020 Apr 18.

Abstract

Cobalt(II)-histidine [Co(II)His] is potentially a better alternative to ferrous complexes in the chemical absorption-biological reduction (CABR) flue gas denitrification process in view of its higher oxygenation reversibility. Though with excellent O2-resistant ability, Co(II)His was still gradually oxidized into Co(III)His, losing NO binding capacity. Thus, Co(III)His biological reduction is an indispensable step in CABR process. Co(III)His reduction by Paracoccus versutus LYM under aerobic condition in the presence of nitrate or nitrite was investigated. Results indicated that simultaneous Co(III)His reduction and aerobic denitrification were achieved by strain LYM. Co(III)His reduction was significantly promoted by denitrification process, but dramatically inhibited by 5-15 mM sulfite. Co(II)His absorbent regeneration could be facilitated by adjusting O2 supply properly or adding nitrogen and carbon source regularly. These findings provide a basis for the application of Co(II)His as the absorbent in the CABR process and qualify P. versutus LYM as an applicable and competitive strain for this process.

Keywords: Aerobic denitrification; Cobalt(III)-histidine reduction; Paracoccus versutus; Sulfite.

MeSH terms

  • Cobalt
  • Denitrification*
  • Histidine
  • Nitrates
  • Nitrites
  • Nitrogen
  • Paracoccus*

Substances

  • Nitrates
  • Nitrites
  • Cobalt
  • Histidine
  • Nitrogen

Supplementary concepts

  • Paracoccus versutus