# Bioprospecting of Marine Organisms: Exploring Antibacterial Activities in Aqueous and Organic Extracts

## TL;DR

This study explores antibacterial compounds in marine organisms from Brazil's coast, finding that organic extracts from certain sponges and seaweeds show promise against bacteria.

## Contribution

The study identifies specific marine species with antibacterial potential, emphasizing organic extracts and Gram-positive bacteria susceptibility.

## Key findings

- 30.7% of marine organism extracts showed antibacterial activity, with organic extracts being more effective.
- Sponge species like Aplysina and Mycale, and seaweed Amansia multifida, showed notable antibacterial effects.
- Gram-positive bacteria were more susceptible to the extracts than Gram-negative bacteria.

## Abstract

This study evaluated the antibacterial activity of aqueous and organic extracts from 78 marine organisms, including seaweeds and sponges, collected along the coast of Ceará, Brazil. Extracts were obtained by maceration using distilled water and 50% acetonitrile and tested against Staphylococcus aureus, Staphylococcus epidermidis (Gram-positive), and Escherichia coli (Gram-negative) using the disk diffusion method, and inhibition zone diameters were measured. Antibacterial activity was observed in 30.7% of the extracts, with organic extracts showing higher efficacy. Several sponge species, particularly those from the genus Aplysina, as well as Amphimedon compressa, Amphimedon viridis, Mycale sp., and Pseudosuberites sp., demonstrated notable inhibitory effects. While seaweed aqueous extracts showed no activity, some organic extracts—especially from Amansia multifida—were effective against Gram-positive strains. In general, Gram-positive bacteria were more susceptible than Gram-negative bacteria. These findings underscore the biotechnological potential of marine organisms from the Brazilian coast as promising sources of antibacterial compounds and support future efforts focused on the isolation, characterization, and toxicological evaluation of active metabolites for pharmaceutical and industrial applications.