Reduction of selenite to elemental selenium by Enterobacter cloacae SLD1a-1  [1998]

Dungan, R.S. Frankenberger, W.T. Jr.

Access the full text:

The facultative anaerobic bacterium Enterobacter cloacae strain SLD1a-1 (ATCC-700258) was studied in washed cell suspensions to assess optimal conditions required for the reduction of selenite (SeO3(2-)) to elemental selenium (Se(0)). Enterobacter cloacae using glucose (1.4 mM) as an electron donor removed 79% of the added SeO3(2-) (7.9 micromolar) from solution in 2.5 h. Optimal SeO3(2-) reduction occurred at a pH of 6.5 and a temperature of 40 degrees C. Carbohydrate sources arabinose, xylose, and sorbose were found to significantly enhance SeO3(2-) reduction over that of glucose. The reduction of SeO3(2-) at 7.9 micromolar was inhibited by nitrate at levels 1 to 100 times greater, nitrite at levels 5 and 10 times greater, while sulfite at levels of two to four times greater was found to stimulate the reduction of SeO3(2-). Enterobacter cloacae grows on anaerobically incubated plates containing NO3(-) as the sole terminal electron acceptor and acetate as the electron donor. Use of SeO3(2-) as the terminal electron acceptor during anaerobic respiration did not support growth and could only be reduced to Se(0) when NO3(-) was present.

Other subjects

  • Enterobacter cloacae
  • selenium
  • biodegradation

From the journal

Journal of environmental quality

ISSN : 0047-2425