ABSTRACT
Previously isolated dissimilatory perchlorate-reducing bacteria (DPRB) have been primarily affiliated with the
Betaproteobacteria
. Enrichments from the cathodic chamber of a bioelectrical reactor (BER) inoculated from creek water in Berkeley, CA, yielded a novel organism most closely related to a previously described strain, WD (99% 16S rRNA gene identity). Strain VDY
T
has 96% 16S rRNA gene identity to both
Magnetospirillum gryphiswaldense
and
Magnetospirillum magnetotacticum
, and along with strain WD, distinguishes a clade of perchlorate-reducing
Magnetospirillum
species in the
Alphaproteobacteria
. In spite of the phylogenetic location of VDY
T
, attempted PCR for the key magnetosome formation genes
mamI
and
mamL
was negative. Strain VDY
T
was motile, non-spore forming, and, in addition to perchlorate, could use oxygen, chlorate, nitrate, nitrite, and nitrous oxide as alternative electron acceptors with acetate as the electron donor. Transient chlorate accumulation occurred during respiration of perchlorate. The organism made use of fermentation end products, such as acetate and ethanol, as carbon sources and electron donors for heterotrophic growth, and in addition, strain VDY
T
could grow chemolithotrophically with hydrogen serving as the electron donor. VDY
T
contains a copy of the RuBisCo
cbbM
gene, which was expressed under autotrophic but not heterotrophic conditions. DNA-DNA hybridization with strain WD confirmed VDY
T
as a separate species (46.2% identity), and the name
Magnetospirillum bellicus
sp. nov. (DSM 21662, ATCC BAA-1730) is proposed.