Response of Westiellopsis prolifica and Anabaena sp. to salt stress

Abstract

The response of a salt-tolerantWestiellopsis prolifica ARM 366 and a sensitiveAnabaena C-10 to NaCl was studied. While the former could tolerate up to 400mm NaCl, the latter was highly sensitive to concentrations above 50mm NaCl. Under salt stress, the tolerantW. prolifica showed an increased nitrogen demand as exemplified by high nitrogenase activity, and growth inhibition at higher concentrations of NaCl did not appear to be a direct consequence of inhibition of nitrogen fixation. One of the striking responses to Na⁺ challenge by the tolerantW. prolifica was the excess production of extracellular polysaccharides which adsorbed the bulk of the Na⁺. The influx of Na⁺ into the cell was comparatively small.