10.22376/ijpbs.2019.10.1.p1-12 Volume 6 Issue 4 2015 (October - December) Scytonemin is a naturally occurring UV screening pigment, found in extracellular sheaths of most of the Nostocales. Accumulation of scytonemin in extracellular sheath is regulated by many of the nutrients and physiochemical parameters. The purpose of this study was to evaluate BG 11 media component by using Plackett-Burman statistical design and study their effective concentrations on the production of scytonemin, by using four isolated Nostocales lessThan i greaterThan Scytonema sp., Plectonema sp., Spirulina sp., and Lyngbya sp. lessThan /i greaterThan All four fresh water cyanobacteria were adopted for 3% salinity and BG 11 media is then replaced with sea water, by adjusting evaluated components and providing optimum physiochemical conditions for scytonemin production. As per our results, NaNO lessThan sub greaterThan 3 lessThan /sub greaterThan (nitrate), K lessThan sub greaterThan 2 lessThan /sub greaterThan HPO lessThan sub greaterThan 4 lessThan /sub greaterThan (phosphate + potassium), CaCl lessThan sub greaterThan 2 lessThan /sub greaterThan (calcium) and MgSO lessThan sub greaterThan 4 lessThan /sub greaterThan (Magnesium) has a significant effect on scytonemin production. NaNO lessThan sub greaterThan 3 lessThan /sub greaterThan concentration varies from 0% to 0.015%. MgSO lessThan sub greaterThan 4 lessThan /sub greaterThan at 10 times more concentration increases scytonemin yield by 2 folds. CaCl lessThan sub greaterThan 2 lessThan /sub greaterThan presence decreases scytonemin yield, optimized concentration was 10 time less as that of original concentration. Optimized concentrations for pH, salinity and temperature were 7- 8, 2% and 28 – 30 lessThan sup greaterThan 0 lessThan /sup greaterThan C, respectively. Scytonemin produced by using sea water culture was about 2.5% of dry weight of all 4 cyanobacteria. PRANAY ABHANG AND GIRISH PATHADE Scytonemin, UV screening pigment, Nostocales, Plackett-Burman design. 296-305