International Journal of Marine Science 2015, Vol.5, No.50: 1-5
4
Figure 4 Growth pattern of
C.bifermentans
in different
concentrations of copper
Figure 5 Heavy metal resistance of
Clostridium bifermentans
Clostridium bifermentans
. The resistant pattern of
Clostridium bifermentans
to lead, cadmium and
copper was Pb=Cd>Cu. Under metal stress, metal
resistant bacteria adapt rapidly by spread of R factors
than by mutation (Bhattacherjee, et al.
,
1988 and
Silver and Misra. 1988). Various studies have reported
that in heavymetal polluted ecosystem the microorganism
will develop some specific tolerance mechanism.
Hence bacteria which are resistant to heavy metal may
be used for bioremediation of metal polluted ecosystems
(Nies., 1999, Taniguchi et al., 2000).
Clostridium
species have important role in bioremediation of
metals and their metal precipitation may increase pH,
redox potential and their metabolite production will
favors SRB activity (Alexandrino et al., 2014).
4 Conclusions
Bioremediation of heavy metals by bacterial strains
was greatly accepted by scientific community. In this
study
Clostridium bifermentans
has exhibited tolerance to
all three heavy metals (Pb, Cd, and Cu). An MIC of 12
µg/mL was noticed in lead and cadmium and 10
µg/mL for copper. Growth pattern of
Clostridium
bifermentans
in different concentration of lead showed
significantly high compared with control. But cadmium
and copper caused for a decrease in the rate of growth
at different concentration (above 2 µg/mL). It is
concluded that
Clostridium bifermentans
have
significant potential in bioremediation of lead. Thus,
in future this bacterium could be used for the
detoxification of lead in contaminated environment.
Future studies are needed to understand the bacterial
mechanism against heavy metals.
Acknowledgement
The first author acknowledges the UGC-RGNF for financial
support. The authors acknowledge the facilities given by
DST-FIST and DST-PURSE, Government of India. The authors
also wish to acknowledge the suggestions by the anonymous
reviewers in improving the quality of the manuscript.
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