S. Das et al. / Open Journal of Ecology 1 (2011) 35-40 39
Mic r obial growth of 3 so il segment in anaerobic c on dit ion
0
1
2
3
4
5
0 20406080
I ncubation Period (hour)
CFU X10
6
gm
-1
dry w e ight of soil
TopSoil
Midd leSoil
B ottomSoil
Figure 4. Growth rate of microbes from 3 soil segments in
anaerobic condition.
rounding environment than the aerobic microbes present
in the top soil segment. This observation can be ex-
plained from the study by Lowe et al. [26]. According to
their report it can be predicted that anaerobic bacteria
can grow at environmental extremes of temperature, pH,
salinity, substrate toxicity, or available free energy and
anaerobes, unlike aerobes, appear to have evolved more
energy-conserving mechanisms for physiological adapta-
tion to environmental stresses such as novel enzyme ac-
tivities and stabilities and novel membrane lipid compo-
sitions and functions. Sea level rising due to global
warming may cause fluctuation of water as well as soil
salinity which may ultimately hamper the activity of
aerobic bacteria a little more than that of anaerobic bac-
teria. Soil salinity is a stress factor relating to microbial
selection process and can reduce bacterial diversity and
control microbial abundance, composition and functions
[27]. Thus oxidation of the reduced trace gas like meth-
ane by aerobic bacteria like methanotrops could be hin-
dered more than that of in present. In such condition
mangrove sediment may emit more methane to the at-
mosphere.
4. CONCLUSIONS
This bacterial growth profile study reveals that a per-
fect stratification exists between the depths of soil in the
mangrove ecosystem and salt tolerance nature of the
bacteria. This stratification may be responsible for a
perfect nutritive management of the mangrove forests.
Thus they provide unique ecological niche to variety of
microorganisms. More anoxic and salty nature of the
Sundarban Mangrove Forest may play a crucial role to
reflect on the microbial activity regarding biogeochemi-
cal cycles.
5. ACKNOWLEDGEMENTS
We would like to acknowledge UGC, New Delhi for providing fel-
lowship to Sudhajit Das and department of forest, Govt. of West Ben-
gal for permitting us to do this study in Sundarban mangrove forest.
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