Sodium transport in filamentous nitrogen fixing cyanobacteria

Apte, Shree Kumar ; Thomas, Joseph (1983) Sodium transport in filamentous nitrogen fixing cyanobacteria Journal of Biosciences, 5 (3). pp. 225-233. ISSN 0250-5991

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Two filamentous, nitrogen fixing cyanobacteria were examined for their salt tolerance and sodium (Na+) transport. Anabaena torulosa, a saline form, grew efficiently and fixed nitrogen even at 150 mM salt (NaCl) concentration while, Anabaena L-31, a fresh water cyanobacterium, failed to grow beyond 35 mM NaCl. Anabaena torulosa showed a rapidly saturating kinetics of Na+ transport with a high affinity for Na+ (Km, 0.3 mM). Anabaena L-31 had a much lower affinity for Na+ (Km, 2.8 mM) than Anabaena torulosa and the pattern of uptake was somewhat different. Both Anabaena spp. exhibited an active Na+ extrusion which seems to be mediated by a Na+-K+ ATPase and aided by oxidative phosphorylation. Anabaena L-31 was found to retain much more intracellular Na+ than Anabaena torulosa. The results suggest that the saline form tolerates high Na+ concentrations by curtailing its influx and also by an efficient Na+ extrusion, although these alone may not entirely account for its success in saline environment.

Item Type:Article
Source:Copyright of this article belongs to Indian Academy of Sciences.
Keywords:Nitrogen Fixation; Cyanobacteria; Sodium Transport; Salt Tolerance
ID Code:796
Deposited On:25 Sep 2010 04:41
Last Modified:16 May 2016 11:59

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