NITROGEN AND PHOSPHORUS METABOLISM OF ANABAENA DOLIOLUM UNDER UV-B AND PESTICIDE STRESS

The effects of UV-B and pesticides (Butachlor and Carbofuran) on nitrogen and phosphorus metabolism have been studied on filamentous, nitrogen-fixing cyanobacterium, Anabaena doliolum. The study showed a decrease in the uptake of NH4+, PO4-3, activities of nitrogenase, glutamine synthetase, and alkaline phosphatase, when the cells were exposed to UV-B and pesticides. The interaction of two stresses showed the additive type of behavior for the studied parameters. In contrast, a significant increase in NO3- uptake and nitrate reductase activity was seen when Anabaena cells were exposed to different doses of UV-B.

Induction of Colon tumor and Intestinal tumor in Swiss Albino Mice by the DihydroMicrocystin –LR, [D‐Asp3] Microcystin‐WR and [D‐Asp3] Microcystin‐HtyR produced by the Cyanobacterial strains Isolated from water bodies in semi‐desert region of India

The crude extracts of two cyanobacterial strains, isolated from water bodiesof Shekhawati region of India, and identified as Anabaena doliolum andNostoc spongiaeforme, in‐vivo mouse bioassay model. A dose of 100μg of totalprotein/kg of body weight showed restlessness, spasmodic leaping, slowmovement and loss of co ‐ordination within 6hours of intraperitonial (i.p)administration in Swiss albino mice. Further purification of crude extractswith the help of thin layer chromatography using silica gel GF 60 plates,showed four spots for each of these strains. The chronic toxicity studies withsub lethal dose of spot ‐3 from A. doliolum have shown to cause colon tumors,whereas sub lethal dose of spot ‐3 from N. spongiaeforme induced theintestinal tumors. An increase in oxidative stress (MDA level), serum ALT,ALP, AST and LDH level was also found in both the cases. These spots werefurther analysis with HPLC and MALDI TOFF Ms and were identified as DihydroMicrocystin –LR and [D ‐Asp3] Microcystin‐WR in case of Ad spot‐3 andMicrocystin ‐LR and [D‐Asp3] microcystin‐HtyR in case of Ns spot‐3.showed high level of hepatotoxicity and tumor promotingactivity in