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Reduction of Selenite to Elemental Selenium by Enterobacter cloacae SLD1a‐1
Author(s) -
Dungan R. S.,
Frankenberger W. T.
Publication year - 1998
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq1998.00472425002700060005x
Subject(s) - enterobacter cloacae , selenium , electron acceptor , enterobacter , chemistry , electron donor , nitrite , thiosulfate , nuclear chemistry , sulfite , xylose , anaerobic exercise , fermentation , food science , biochemistry , nitrate , biology , enterobacteriaceae , organic chemistry , catalysis , escherichia coli , sulfur , gene , physiology
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 (SeO 3 2− ) to elemental selenium (Se 0 ). Enterobacter cloacae using glucose (1.4 m M ) as an electron donor removed 79% of the added SeO 3 2− (7.9 m M ) from solution in 2.5 h. Optimal SeO 3 2− reduction occurred at a pH of 6.5 and a temperature of 40°C. Carbohydrate sources arabinose, xylose, and sorbose were found to significantly enhance SeO 3 2− reduction over that of glucose. The reduction of SeO 3 2− at 7.9 m M 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 SeO 3 2− . Enterobacter cloacae grows on anaerobically incubated plates containing NO 3 − as the sole terminal electron acceptor and acetate as the electron donor. Use of SeO 3 2− as the terminal electron acceptor during anaerobic respiration did not support growth and could only be reduced to Se 0 when NO 3 − was present.