Marine Actinomycetes Associated with Stony Corals: A Potential Hotspot for Specialized Metabolites

Abstract

Microbial secondary metabolites are an important source of antibiotics currently available for combating drug-resistant pathogens. These important secondary metabolites are produced by various microorganisms, including Actinobacteria. Actinobacteria have a colossal genome with a wide array of genes that code for several bioactive metabolites and enzymes. Numerous studies have reported the isolation and screening of millions of strains of actinomycetes from various habitats for specialized metabolites worldwide. Looking at the extent of the importance of actinomycetes in various fields, corals are highlighted as a potential hotspot for untapped secondary metabolites and new bioactive metabolites. Unfortunately, knowledge about the diversity, distribution and biochemistry of marine actinomycetes compared to hard corals is limited. In this review, we aim to summarize the recent knowledge on the isolation, diversity, distribution and discovery of natural compounds from marine actinomycetes associated with hard corals. A total of 11 new species of actinomycetes, representing nine different families of actinomycetes, were recovered from hard corals during the period from 2007 to 2022. In addition, this study examined a total of 13 new compounds produced by five genera of actinomycetes reported from 2017 to 2022 with antibacterial, antifungal and cytotoxic activities. Coral-derived actinomycetes have different mechanisms of action against their competitors.

Prioritization of Microorganisms Isolated from the Indian Ocean Sponge Scopalina hapalia Based on Metabolomic Diversity and Biological Activity for the Discovery of Natural Products

“…Within these hosts, there are microbiota that can consist of hundreds of bacteria belonging to different genera [ 22 , 23 , 24 ]. These bacteria may be responsible for the production of specialized metabolites in holobionts and exhibit a great potential for the discovery of new molecules with diverse biological activities [ 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ]. However, the large number of microorganisms isolated from these complex systems makes their exploration fastidious, time-consuming and expensive for research.…”

“…This microbiome can be composed of different microbial populations such as fungi, bacteria or microalgae [ 24 , 25 , 26 , 27 , 28 ]. Amongst these communities, actinobacteria are widely known to produce bioactive molecules of interest [ 26 , 27 , 28 , 29 , 30 ].…”

“…This microbiome can be composed of different microbial populations such as fungi, bacteria or microalgae [ 24 , 25 , 26 , 27 , 28 ]. Amongst these communities, actinobacteria are widely known to produce bioactive molecules of interest [ 26 , 27 , 28 , 29 , 30 ]. Unlike their host, microorganisms have the advantage of being easily cultivable, and thus, a sustainable production of bioactive compounds can be achieved.…”

“…For this study, 9 microbial strains were pre-selected among 124 isolated from this sponge based on their potential to produce anti-aging compounds in previous biological tests [ 24 ]. The selected strains also belong to families already known in the literature for their production of metabolites of interest, such as Bacillus [ 43 ] or actinobacteria [ 25 , 26 , 27 , 28 , 29 , 30 ]. Microbial compounds such as salinosporamide, staurosporine or erythromycin have proven their biological interest [ 44 , 45 , 46 ].…”

Saccharopolyspora sp. NFXS83 in Marine Biotechnological Applications: From Microalgae Growth Promotion to the Production of Secondary Metabolites

“…For example, some actinobacteria have been shown to produce compounds that inhibit the growth of harmful algae, potentially affecting their abundance and distribution in the ocean [11]. On the other hand, some actinobacteria producing antimicrobial compounds may have a mutualistic relationship with marine organisms such as corals, protecting these organisms from pathogens and other predators [12].…”