Back to Contents

FREE FULL TEXT PDF

BIOLOGICAL ACTIVITY AND ELEMENTOLOGY OF BENTHIC ALGAE FROM KARACHI COAST

MUHAMMAD AFZAL RIZVI AND MUSTAFA SHAMEEL*

Abstract: Forty species of seaweeds were collected from Karachi coast and several biological tests conducted on them inorder to investigate their antibacterial, antifungal, phytotoxic and insecticidal activities. Brown seaweeds showed greater antibacterial activity than the green and red ones. Chaetomorpha antennina, Gracilaria foliifera, Jolyna laminarioides exhibited greatest antifungal activity and Codium shameelii the poorest. The highest phytotoxic activity (100 %) was displayed by Asparagopsis taxiformis at 1000 µg/mL concentration, while Osmundea pinnatifida showed the low insecticidal activity as compared to the other investigated species. Certain elements e.g. Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Na, Pb, Zn were determined quantitatively. Among them Ca, Cr and Pb were found to occur in largest amount in green seaweeds, Co, Cu, Fe and Zn in greatest quantity in brown seaweeds, while Cd, K, Mg and Na in highest proportion in the investigated red seaweeds, indicating that various phyla of algae behaved differently in their elemental composition.

Hamdard Institute of Advanced Studies and Research, Hamdard University, Karachi-74600, Pakistan.
Department of Botany, University of Karachi, Karachi-75270, Pakistan.