ASSESSMENT OF THE EFFECT OF THE TOXICITY OF A TEXTILE DYE ON NOSTOC-MUSCORUM ISU, A DIAZOTROPHIC CYANOBACTERIUM

The impact of graded concentrations (5, 10, 15 and 20 mg dm(-3)) of ac id mordant Metomega Chrome Orange GL, a common dye used in woollen, ca rpet and textile industries, was studied an protein and pigment conten t and photosynthetic oxygen evolution in a diazotrophic cyanobacterium Nostoc muscorum. The lower concentration of 5 mg dm(-3) showed a negl igible effect on protein and pigment content and photosynthetic oxygen evolution, whereas at higher concentrations a drastic decrease in the above parameters was observed. The highest concentration of 20 mg dm( -3) resulted in a decrease of protein, chlorophyll a, phycocyanin and carotenoid content by 72, 76, 54 and 17% of the control, respectively. Photosynthetic oxygen evolution also decreased by 92% of the control at this concentration of the dye.