Antimicrobial Activity of Sea Cucumber (Stichopus variegatus) Body Wall Extract in Chabahar Bay, Oman Sea

Abstract

Seas and oceans have been recognized as a rich source of metabolites and bioactive compounds with biodiversity and drug activity. These compounds have accumulated in various organisms. Bioactive compounds can be extracted from various animal groups, such as coral, crabs, moss animals, Echinodermata, case-bearers, fishes, and sponges. Objectives: Antimicrobial extracts of the sea cucumber body wall (Stichopus variegatus), collected from Chabahar Bay, were tested for four bacterial, fungal, and yeast species. Methods: The disk diffusion method was used in this study. The McFarland 0.5 standard was used in the preparation of suspensions of the mentioned microorganisms under a hood. Next, the species were cultured with a swab on a Mueller-Hinton agar for bacteria and on a Sabouraud dextrose agar for fungi. Subsequently, the disks, with appropriate concentrations, were placed on microbiological growth media. Results: The results of the study showed that the best effect belonged to the aqueous methanol extract of the sea cucumber body wall, with an 8 mg/mL concentration on E. coli, with an inhibition zone diameter of 12.26 mm. The lowest inhibition zone diameter belonged to the methanol extract of white strands, with a 2 mg/mL concentration on C. albicans and an inhibition zone diameter of 1.16 mm. The n-hexane and chloroform extracts had no effect. Conclusions: Comparison of these tests indicates that sea cucumbers have an innate immunity system, which can be considered a potential source for discovering antimicrobial peptides.