Isolation of Bioactive Proteins from the Marine Sponge Spongosorites halichondriodes (Dendy, 1905)

The marine sponge Spongosorites halichondriodes, collected from Mumbai coastal area, was studied for presence of bioactive proteins. Sponge species was identified based on Spicules morphology. Crude protein from the sponge was extracted at the concentration of 5.3 mg/mL in methanol and 3.4 mg/mL in aqueous extract. Six bacterial species (Klebsiella pneumonia, Salmonella typhi, Staphylococcus aureus, Bacillus subtilis, Proteus vulgaris and Escherichia coli) were tested against crude protein extract of the sponge. The antimicrobial activity of crude extract against six bacterial species showed the clear inhibition zone against Klebsiella pneumoniae, Salmonella typhi and Escherichia coli in methanol extract and aqueous extracts. Both the extracts exhibited hemolytic activity which was estimated as 1.50 ht/mg for methanol and 2.35 ht/mg for aqueous extract. The methanol and aqueous extract were checked for presence of cytotoxic activity, using Brine Shrimp assay and showed enough cytotoxicity against Artemia salina. The LC doses were calculated as 1000 50 and 10 mcg/ ml for Methanol and Aqueous extracts respectively, which showed higher toxicity in aqueous fraction. The purification of protein was done by using DEAE cellulose and sephadex coloumn. On SDS-PAGE the crude protein yielded 6 well-defined bands of 20 kDa, 26 kDa, 40 kDa, 50 kDa, 80 kDa and 120 kDa in methanol as well as aqueous extracts.