Bacterial bioremediation of selenium oxyanions using a dynamic flow bioreactor and headspace analysis
- Sam Houston State Univ., Huntsville, TX (United States). Dept. of Chemistry
- Univ. of Zuerich (Switzerland). Inst. of Plant Biology
The volatile products of the biological reduction and methylation of selenium`s most common oxyanions, selenate and selenite, were determined using capillary gas chromatography and fluorine-induced chemiluminescence detection. Dimethyl selenide and dimethyl diselenide were detected in the headspace above cultures of bacteria resistant to this metalloid using static and dynamic headspace sampling techniques. Fluorine-induced chemiluminescence detection was applied to determine the relative concentrations of the organosulfur and organoselenium species released over many days of culture growth at a controlled temperature and purge rate. A selenium-resistant bacterium, Pseudomonas fluorescens K27, and a phototrophic bacterium Rhodobacter sphaeroides 2.4.1 were exposed to SeO{sub 4}{sup 2{minus}}, and the cultures` headspaces were examined over a period of several days for volatile selenium-containing products. The results show that the relative production of the volatile species over time depicts a pattern generally independent of the growth phase in the case of the phototrophic bacterium; the concentrations of metabolic dimethyl sulfide and dimethyl selenide determined in static headspace were highest after the microbe had been in stationary phase for 4 days.
- OSTI ID:
- 477271
- Report Number(s):
- CONF-950483--; ISBN 1-57477-011-X
- Country of Publication:
- United States
- Language:
- English
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