Salt tolerance in recombinant glycinebetaine synthesizing freshwater cyanobacteria Anabaena PCC7120 and Anabaena doliolum and a sodic soil cyanobacterium anabaena fertilissima

Abstract

Microbes, during their life cycle face multiple biotic and abiotic stresses that adversely affect their growth and developmental processes, diminish productivity and even intimidate their survival. Among the abiotic stresses, salinity is wide spread throughout the globe. Insufficient rainfall (inept to leach salts from the soil), high evapotranspiration, weathering of rocks, seawater intrusion and aerosol deposits have accumulated enormous amount of salt over time. Salinity not only affects the sustainability of productive agricultural land and obliterates ecosystems but also encompasses numerous social, economic and environmental consequences. Secondary salinization caused by deforestation, replacement of native vegetation with shallow-rooted crops, excessive use of irrigation water, inefficient drainage system and anthropogenic land-use practices have become another major problem and is expected to increase in near future. newlineCyanobacteria are a large group of oxygenic photosynthetic prokaryotes and occupy a unique position among organisms due to the transformation of the planet s reduced atmosphere to an oxidized one. They play a vital role in biogeochemical cycles of carbon and nitrogen, the most important nutrient for photosynthesis and growth. The group exhibits vast range of morphologies and mode of nutrition, and have acquired the capacity to grow in widely different extreme environments due to their adaptation to the extreme changes during their long evolutionary era. newline