<div>Background: The marine organisms are well known to produce many bioactives molecules, which serve various functions. In the present paper, the sea urchin Sphaerechinus granularis was used as biological material for exploring the new bioactive molecules.&nbsp; 
 
Methods: The study was carried out in spring 2019 (April), sea urchins Sphaerechinus granularis were harvested from coastal areas of El-Kala. All the sea urchins collected were transported to the laboratory in sea water. The test were opened and gonads removed. The gonads were pooled for biochemical and microbiological analysis. 
 
Result: The screening revealed the presence of saponosides, mucilages, alkaloids, combined anthraquinones (C-heterosides), polyphenols and flavonoids. The biochemical analysis of the gonads has shown that they are rich in secondary metabolites. The antioxidant capacity indicated that the methanolic extract is better compared to the aqueous extract. The antibacterial effect were observed in the methanolic extract while the aqueous extract showed no antibacterial activity. The calculation of the ratio minimum inhibitory concentration/minimum bactericidal concentration had indicated a bactericidal effect with respect to Gram negative bacteria and bacteriostatic with respect to Gram positive bacteria for the methanolic extract. Aqueous extract reported no effect.</div>

The Sea Urchin Sphaerechinus granularis (Lamarck, 1816) from the Mediterranean Sea: A New Natural Source of Antibacterial and Antioxidant Molecules