BIOAUGMENTATION WITH PSEUDOMONAS STUTZERI KC FOR CARBON TETRACHLORIDE REMEDIATION - Bioaugmentation for Groundwater Remediation - page 279

Ultimately, bioaugmentation with P. stutzeri KC may not be needed to obtain the benefits
accrued from PDTC production. PDTC is a small molecule capable of passing through an ultrafil-
tration membrane. It may thus be possible to produce PDTC aboveground in a membrane bioreactor
operated under ideal conditions for PDTC production or using strains genetically engineered to
overproduce PDTC. Circulation of the filtered supernatant through the subsurface could then be
used for remediation, especially if combined with biostimulation of indigenous microflora.
Tatara ( 1996 ) demonstrated that the CT-transformation activity secreted by strain KC
passed through a column of Schoolcraft aquifer solids without retardation. Thus, circulation
of PDTC through a region in which electron donor has been added for biostimulation could
presumably enable controlled CT dechlorination while avoiding the need for pH adjustment and
ecological issues associated with maintaining the activity of P. stutzeri KC in the subsurface
over long-time periods.
Finally, if cost-effective, even chemically synthesized PDTC (Table 9.6 ) conceivably could
be added as a biostimulation supplement. Such a strategy might be particularly valuable for
environments containing CT at levels above the growth limit of strain KC (~5 mg/L).
REFERENCES
Asmus K-D, Bahnemann D, Krischer K, Lal M, M¨nig G. 1985. One-electron induced degra-
dation of halogenated methanes and ethanes in oxygenated and anoxic aqueous solutions.
Life Chem Rep 3:1-15.
ATSDR (Agency for Toxic Substances and Disease Registry). 2005. US Department of Health
and Human Services. ToxFaqs for Carbon Tetrachloride. CAS#: 56-23-5. August.
Begley TP, Xi J, Kinsland C, Taylor SM, McLafferty FW. 1999. The enzymology of sulfur
activation during thiamin and biotin biosynthesis. Curr Opin Chem Biol 3:623-629.
Blickling S, Renner C, Laber B, Pohlenz HD, Holak TA, Huber R. 1997. Reaction mechanism of
Escherichia coli dihydrodipicolinate synthase investigated by X-ray crystallography and
NMR spectroscopy. Biochem 36:24-33.
Cortese M, Paszczynski A, Lewis TA, Sebat J, Crawford RL. 2002. Metal chelating properties
of pyridine-2,6-bis(thiocarboxylic acid) produced by Pseudomonas spp. and the biological
activities of the formed complexes. BioMetals 15:103-120.
Criddle CS, DeWitt JT, Grbic-Galic D, McCarty PL. 1990, Transformation of carbon tetrachlo-
ride by Pseudomonas sp. strain KC under denitrification conditions. Appl Environ Micro-
biol 56:3240-3246.
Dybas M, Tatara G, Criddle CS. 1995a. Localization and characterization of the carbon
tetrachloride transformation activity of Pseudomonas sp. strain KC. Appl Environ Micro-
biol 61:758-762.
Dybas M, Tatara G, Knoll W, Mayotte T, Criddle CS. 1995b. Niche adjustment for bioaug-
mentation with Pseudomonas sp. strain KC. In Hinchee RE, Frederickson J, Alleman BC,
eds, Bioaugmentation for Site Remediation. Bioremediation Series 3(3), Battelle Press,
Columbus, OH, USA, pp 77-84.
Dybas MJ, Barcelona M, Bezborodnikov S, Davies S, Forney L, Kawka O, Mayotte T,
Sepulveda-Torres L, Smalla K, Sneathen M, Tiedje J, Voice T, Wiggert D, Witt ME,
Criddle CS. 1998. Pilot-scale evaluation of bioaugmentation for in-situ remediation of a carbon
tetrachloride-contaminated aquifer. Environ Sci Technol 32:3598-3611.
Dybas MJ, Hyndman DW, Heine R, Linning K, Tiedje J, Voice T, Wallace R, Wiggert D, Zhao
X, Artuz R, Criddle CS. 2002. Development, operation, and long-term performance of a
full-scale biocurtain utilizing bioaugmentation. Environ Sci Technol 36:3635-3644.