Na(+)-stimulated nitrate uptake with increased activity under osmotic upshift in Synechocystis sp strain PCC 6803
2011 (English)In: World Journal of Microbiology & Biotechnology, ISSN 0959-3993, E-ISSN 1573-0972, Vol. 27, no 10, 2467-2473 p.Article in journal (Refereed) Published
In the non-diazotrophic cyanobacterium Synechocystis sp. strain PCC 6803, an osmolality of 30 and 40 mosmol/kg sorbitol and NaCl resulted in 3.5- and 4.5-fold increase of nitrate uptake, respectively. The NaCl-stimulated uptake was abolished by treatment with chloramphenicol. At 25 mosmol/kg or higher, NaCl induced higher nitrate uptake than sorbitol suggesting an ionic effect of Na(+). The nitrate uptake in Synechocystis showed K (s) and V (max) values of 46 mu M and 1.37 mu mol/min/mg Chl, respectively. Mutants disrupted in nitrate and nitrite reductase exhibited a decreased nitrate uptake. Ammonium, chlorate, and dl-glyceraldehyde caused a reduction of nitrate uptake. Dark treatment caused a drastic reduction of uptake by 70% suggesting an energy-dependent system. Nitrate transport was sensitive to various metabolic inhibitors including those dissipating proton gradients and membrane potential. The results suggest that nitrate uptake in Synechocystis is stimulated by Na(+) ions and requires energy provided by the functioning electron transport chain.
Place, publisher, year, edition, pages
2011. Vol. 27, no 10, 2467-2473 p.
Cyanobacteria, Nitrate uptake, Osmotic upshift, Synechocystis
IdentifiersURN: urn:nbn:se:uu:diva-159780DOI: 10.1007/s11274-011-0706-6ISI: 000294966900028OAI: oai:DiVA.org:uu-159780DiVA: diva2:447726