The Bioscan, 4(2): 247-250, 2009
An International Quarterly Journal of Life Sciences
web site: www.thebioscan.in 
CADMIUM INDUCED ALTERATIONS IN THE PHOTOCHEMICAL ACTIVITIES 
OF THE CYANOBACTERIUM, SPIRULINA PLATENSIS (NORDST.) GOM.
A. KARTIK1, SREEDHAR BHATTAR2 AND A. PHANINATHA SARMA1*
1Department of Biochemistry, S.V.University, Tirupati -517 502, A.P.
2Department of Biochemistry, Bharatiya Vidyabhavan P.G.College, Hyderabad - 500 029, A.P.
E-mail: sarmabiochem@gmail.com

KEY WORDS
Cd stress
Electron transport
Photosynthesis
Spirulina platensis
Received on: 17.12.2008 Accepted on: 23.03.2009 *Corresponding Author

ABSTRACT

Experimental evidence shows cadmium induces alterations in photochemical activities at multiple sites. The concentration of cadmium at 0.6 mM is able to cause 55% loss in whole chain as well as 66 % in photosystem II catalyzed electron transfer activities in the intact cells of Spirulina. Compared to photosystem II, the activities catalyzed by photosystem I are less sensitive to cadmium stress. The measurement of photosystem II activity at different irradiations indicated light harvesting complex of photosystem II (Phycobilisomes) are targets for Cadmium induced alterations. Thus cadmium exerts multiple effects on the photosynthetic electron transfer in the cyanobacterium, Spirulina platensis and PS II gets inhibited preferentially than PS I.