Affiliations: Department of Environmental Engineering, Osaka
University, 2-1Yamadaoka, Suita, Osaka 565-0871, Japan.
Note: [] Corresponding Author: Microbial and Genetic Resources Research
Group, Research Institute of Biological Resources, National Institute of
Advanced Industrial Science and Technology, M.E.T.I.,1-1-1, Higashi, Tsukuba,
Ibaraki, 305-8566 Japan.E-mail: lee-th@aist.go.jp
Abstract: A laboratory sequential anaerobic-aerobic bioreactor system,which
consisted of an anaerobic fixed film reactor and two aerobic chemostats, was
set up to degrade tetrachloroethylene (PCE) without accumulating highly toxic
degradation intermediates. A soil (ca. 150 mg/liter) of PCE stoichiometrically
intocis-1,2-dichloroethylene (cis-DCE), was attached to ceramic media in the
anaerobic fixed film reactor. A phenol degrading strain, Alcaligenes sp. R5,
which can efficiently degrade cis-DCE byco-metabolic oxidation, was used as
inoculum for the aerobicchemostats consisted of a transformation reactor and a
growth reactor. The anaerobic fixed film bioreactor showed more than 99 %of PCE
transformation into cis-DCE in the range of influent PCE48h. On the other hand,
efficient degradation of the resultant cis-DCE by strain R5 in the following
aerobic system could not beachieved due to oxygen limitation. However, 54% of
the maximum (H_2O_2) was supplemented to the transformation reactor as an
additional oxygen source. Further studies are needed to achieve more efficient
co-metabolic degradation of cis-DCE in the aerobic reactor.
