Developing a Method for Determining
the Mass Balance of Selenium Bioprocessed by a Selenium-Resistant
Bacterium Grown in the Presence
J. Bius and T. G.
Department of Chemistry
Sam Houston State University
Huntsville, Texas 77341-2117
Bioreactor experiments of 2.7 L volume were carried out
using a selenium-resistant bacterium, Pseudomonas fluorescens K27
amended with 10 mM selenite as the sodium salt. After growing the culture
into the stationary phase (anaerobically at 30 degrees C), samples were
harvested from the bioreactor and separated into solid and liquid phases.
Selenium was determined in each phase following their separation by centrifugation
and decantation. The method to detect selenium was hydride generation atomic
absorption spectrometry. Seven samples taken from 4 different bioreactor
cultures show an average of 7.9% (±2.8) conversion of added Se to
the precipitated form, that is, elemental Se or on/in harvested cells.
The balance remained in the supernatant.