African Journal of
Microbiology Research

  • Abbreviation: Afr. J. Microbiol. Res.
  • Language: English
  • ISSN: 1996-0808
  • DOI: 10.5897/AJMR
  • Start Year: 2007
  • Published Articles: 5056

Full Length Research Paper

Interplay between calcium influx and nitrate assimilation in Spirulina platensis

Pradeep Kumar Logeswaran, Vinky Kohli and B Vani*
Centre for Biotechnology, Department of Biological Sciences, Birla Institute of Technology and Science, Pilani - 333031, Rajasthan, India.
Email: [email protected]

  •  Accepted: 22 November 2011
  •  Published: 16 December 2011

Abstract

 

Nitrate assimilation and its interplay with Ca2+ ion transport has been studied in Spirulina platensis PCC 7345, an alkaliphilic filamentous cyanobacterium. We have usedverapamil, a calcium-channel blocker and sodium orthovanadate, a calcium efflux blocker, to study the effect of nitrate assimilatory setupNitrate uptake (NU) increased significantly with verapamil but was inhibited by sodium orthovanadate. Nitrate reductase and nitrite reductase activities were stimulated with verapamil as well as sodium orthovanadate. Glutamine synthetase activity was not significantly altered by both the inhibitors. Our results suggest that the steady state levels of NU, NR and NiR activities are inter linked with Ca2+ influx into the cells from the external medium.

 

Key words: Spirulina, nitrate uptake (NU), nitrate reductase (NR), nitrite reductase, glutamine synthetase.