INFLUENCE OF SALINITY STRESS ON GROWTH AND SOME METABOLIC ACTIVITIES OF ANABAENA SUBCYLINDRICA AND NOSTOC LINCKIA

Abstract

The objective of this study was to investigate the effect of two different concentrations ofCaC]z (0.03, 0.05 M) on growth and some metabolic activities of salinized cultures of Anabaena subcylindrica and Nostoe linckia. The obtained results could be summarized in the following points:- 1) Addition of 0.3 M NaCI in the culture media of both tested algae caused significant inhibition in the measured growth parameters (optical denisty, cell number, dry weight) and caused increase in the cell volume of both organisms all over the cultivation period. However, Addition of CaCh ( 0.03, 0.05 M) to NaCl treated culture induced a considerable stimulation in all growth parameters, except the cell volume which showed no significant change of both organisms in response to CaC]z-additions. 2) Inclusion of 0.3 M NaCI in the culture media of both organisms caused remarkable reduction in the biosynthesis of the different pigment fractions (chlorophyll a, carotenoids, phycocyanin, phycoerythrin and allophycocyanin). However, addition of different concentrations (0.03 or 0.05 M ) of CaC]z in the salinized medium caused significant rise in the different pigment fractions. 3) The results revealed that addition of 0.3 M NaCI in the culture media of .both organisms (Nostoc linckia and Anabeana