DEHALOCOCCOIDES AND REDUCTIVE DECHLORINATION OF CHLORINATED SOLVENTS - Bioaugmentation for Groundwater Remediation - page 44

Table 2.3. Examples of Bacterial Isolates That Partially Dechlorinate PCE to TCE or cis-DCE
PCE Dechlorinating Isolate Dechlorination Activity Reference

Dehalobacter restrictus PCE to cis-DCE Holliger et al., 1998 ;

Wild et al., 1996

Desulfuromonas chloroethenica PCE to cis-DCE Krumholz et al., 1996 ;

Krumholz, 1997

Desulfuromonas michiganensis PCE to cis-DCE Sung et al., 2003

Sulfurospirillum multivorans PCE to cis-DCE Luijten et al., 2003 ;

Neumann et al., 1994

Sulfurospirillum halorespirans PCE to cis-DCE Luijten et al., 2003

Geobacter lovleyi PCE to cis-DCE Sung et al., 2006a

Desulfitobacterium sp. strain
PCE-S

PCE to cis-DCE Miller et al., 1997

Desulfitobacterium hafniense
strain TCE1

PCE to cis-DCE Gerritse et al., 1999

Desulfitobacterium hafniense
strain Y51

PCE to cis-DCE Suyama et al., 2001

Desulfitobacterium hafniense
strain JH1

PCE to cis-DCE Fletcher et al., 2008

Desulfitobacterium sp. strain
PCE1

PCE to TCE Gerritse et al., 1996

Desulfitobacterium sp. strain
Viet1

PCE to TCE L¨ ffler et al., 1997b ;

Tront et al., 2006

Compared with Dehalobacter , these isolates exhibited more versatile metabolisms and
used a greater variety of electron acceptors and electron donors for growth. In contrast to
Dehalobacter strains, PCE-dechlorinating Desulfuromonas isolates cannot use hydrogen but
use several reduced organic compounds, including acetate as electron donors (Krumholz et al.,
1996 ; Sung et al., 2003 ). Geobacter lovleyi strain SZ uses both acetate and hydrogen as electron
donors and was the first PCE-dechlorinating isolate within the Geobacter group. Several
members of this bacterial group are well known for their ability to reduce metals and radio-
nuclides and Geobacter lovleyi reduces PCE and hexavalent uranium simultaneously, suggest-
ing that organisms of this type are promising for remediation of radionuclides and PCE at
mixed waste sites (Sung et al., 2006a ). Sulfurospirillum multivorans (formerly Dehalospirillum
multivorans ) is a well-studied PCE dechlorinator because this organism is easy to culture and
high biomass yields facilitate biochemical studies (John et al., 2009 ; Luijten et al., 2003 ;
Neumann et al., 1996 ; Scholz-Muramatsu et al., 1995 ). Several Desulfitobacterium isolates
were described to dechlorinate PCE, typically to cis -DCE as the dechlorination end product, but
Desulfitobacterium sp. strains PCE1 and Viet1 reduce PCE to TCE. This is an interesting
observation because the characterized PCE reductive dehalogenases (RDases) from Sulfuros-
pirillum , Dehalobacter and Desulfitobacterium reduce PCE to cis -DCE (Maillard et al., 2003 ;
Miller et al., 1998 ; Neumann et al., 1996 ; Suyama et al., 2002 ), suggesting that strain PCE1 and
strain Viet1 possess unique PCE-to-TCE reductive dehalogenase enzyme systems. In any case, a
diverse bacterial group contributes to PCE-to- cis -DCE dechlorination but the microbes con-
tributing to dechlorination past cis -DCE remained elusive.