Sulfide removal and elemental sulfur recycling from a sulfide-polluted medium by Allochromatium vinosum strain 21D

Authors

  • Clemens G. Borkenstein Department of Marine Microbiology, Center for Environmental Research & Technology, University of Bremen, Germany
  • Ulrich Fischer Department of Marine Microbiology, Center for Environmental Research & Technology, University of Bremen, Germany

Keywords:

Allochromatium vinosum, biological sulfide removal, biological sulfur production

Abstract

Phototrophic purple sulfur bacteria oxidize sulfide to elemental sulfur, which is stored as intracellular sulfur globules. The mutant Allochromatium vinosum strain 21D, containing an inactivated dsrB gene, is unable to further oxidize intracellularly stored sulfur to sulfate. This mutant was used as a biocatalyst in a biotechnological process to eliminate sulfide from synthetic wastewater and to recycle elemental sulfur as a raw material. For this purpose, the mutant was grown in an illuminated 5-liter bioreactor (30 μE/m2/s PAR) at 30°C for 61 days in anoxic phototrophic medium. The process of sulfide removal was semi-continuous and consisted of three consecutive fed-batch sections. Sulfide was repeatedly added into the bioreactor and oxidized by the cells to sulfur. In the presence of the mutant, no unwanted sulfate was produced during sulfide removal. A maximum sulfide removal rate of 49.3 μM/h, a maximum sulfide removal efficiency of 98.7%, and 60.4% sulfur recycling were achieved. [Int Microbiol 2006; 9(4):253-258]

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Published

2010-02-23

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Section

Research Articles