Impact of Mercuric Iodide on the Growth of Phormidium spp.

Abstract

Cyanobacteria are microalgae which are freely distributed in aquatic environment. They are photosynthetic organisms and can fix atmospheric nitrogen under anerobic condition. Such cyanobacteria have been applied as a nitrogen fertilizer in agriculture to improve the crop yield. Since the application of chemical fertilizers in crop fields created heavy metal pollution which could be neutralized by microalgae under aquatic environment. They have ability to tolerate the heavy metal concentrations under polluted environment. The present investigation analyzed the impact of mercuric iodide concentrations on the growth of Phormidium spp. which were initially isolated from the paddy field of Selugai, Sivagangai district, Tamil Nadu. They were mass cultured and treated with various concentrations of mercuric iodide (0.1–1 ppm) under laboratory condition. The present strategy enhanced the cyanobacterial populations under different heavy metal concentrations. Phormidium growth was measured and estimated the chlorophyll and phycobillins contents, nitrogen, protein contents and quantity of excreted ammonia. The present investigation has concluded that the selective cyanobacteria Phormidium spp. was well grown at the low concentrations of heavy metals, but higher concentrations affected the growth Phormidium when compared to control. This work confirmed that the mass distribution of cyanobacteria in paddy field preciously fixed atmospheric nitrogen and at the same time they were tolerated against multiple application of agrochemicals with heavy metals normally in crop field. Such organisms could neutralize the heavy metals at minimum level in crop field and improve the crop growth.