Bacterial symbionts of reef invertebrates: screening for anti-pathogenic bacteria activity

Abstract

One of the most serious bottlenecks in developing natural products from coral reefs has been the availability of sufficient biomass to conduct preclinical and clinical studies. Commercial development of new discoveries is further complicated by the fact that most of the metabolites possess highly complex structures, making it difficult to produce them economically via chemical synthesis. There is, however, substantial emerging evidence demonstrating that many natural products extracted from marine invertebrates are in fact the products of associated microorganisms. The general neglect of this highly important field of research and development has led to this study, the intention of which was to isolate bacterial symbionts of reef invertebrates and to screen against clinically important pathogens. A group of invertebrates, namely sponge, soft coral, gorgonian, nudibranch and tunicate, were collected from the Karimunjawa Islands, in the Northern Java Sea, and successfully screened for their antibacterial activity against pathogenic bacteria Escherichia coli, Staphylococcus aureus and Salmonella typhi using an overlay method. Molecular analysis based on 16s rDNA revealed that the active isolates belonged to members of Staphylococcus, Bacillus, Vibrio and Enterobacter. This study highlights the potential of bacterial symbionts of reef invertebrates to serve as a sustainable source of bioactive marine compounds for medical research.