Bangladesh are vulnerable to growing climate change impacts because of their geographical location, high population density, high levels of poverty, high burden of infectious diseases, and the reliance of many livelihoods on climate-sensitive sectors, particularly rural agriculture and fisheries. In Bangladesh, tidal flooding during monsoon, direct inundation by brackish water, and horizontal movement of brackish ground water during dry season aggravate the salinity level on terrestrial and aquatic ecosystems. The whole ecosystems are therefore sensitive to changes in salinity level and the plant communities are continuously struggling to adjust with the new conditions.
This study attempts to isolate, identify and characterize agriculturally-important microorganisms (AIMOs), Azotobacter spp which play a predominant role in maintaining soil arability by fixing atmospheric nitrogen. They are Gram-negative and aerobic soil bacteria which meet about 70 % nitrogen demand in soil. Further, these bacteria are able to solubilize phosphates, produce plant growth hormones and vitamins, and increases the rate of seed germination once inoculated with seeds. Overall, they are renewable, yet a cost-effective source of contributing major plant nutrients
to supplement the nitrogen-containing chemical fertilizer.
In order to cope with the ever-increasing pressures of different abiotic stresses in soil, a good number of Azotobacter spp have been isolated from soil and sediment samples, collected from rice fields of the coastal areas of Bangladesh. Their wide-range tolerances to different abiotic stresses, viz. pH, temperature and salinity revealed that they have the potential of being used as bio-fertilizers without compromising their nitrogen-fixing abilities. This data will be utilized to generate a model forecasting the time-bound arability of the coastal areas to remain productive as the salinity level increases. Further, the isolates exhibited shear resistance to drugs- and heavy metals. The underlying molecular mechanism of this tolerance is now being investigated. Overall, the characterized bacteria could be used as biomarker to assess the productivity of the agricultural lands in one hand, and to produce and apply the potential salt-tolerant strains as bio-fertilizer to increase the soil productivity on the other.