Exploring Marine Rare Actinomycetes: Untapped Resources of Bioactive Compounds in Clinical Development

Abstract

Marine Actinomycetes represent a rich and valuable source of distinct and promising substances. The genus Streptomyces in particular, has been extensively studied due to its ability to produce bioactive compounds and its abundance of biosynthetic gene clusters (BGCs). However, the exclusive focus on Streptomyces has resulted in the rediscovery of known compounds. On the other hand, marine rare Actinomycetes (MRA), comprising Actinomycetes species beyond Streptomyces, also harbor a significant number of BGCs. In this article, we summarize the chemical composition, biological activity, and biosynthetic pathways of compounds sourced from MRA that have been tested in clinical trials for their potential in infection, pain relief, and anticancer treatments. Our particular emphasis lies on compounds derived from MRA associated with marine invertebrates, an area that has been comparatively underexplored when compared to MRA isolated from marine sediment and water. Some notable compounds include rifamycin SV, staurosporine, and tetrodotoxin, which are produced by actinomycetes from the genera Salinospora, Micromonospora, and Nocardiopsis. The findings of this overview shed light on the potential of MRA associated with marine invertebrates to yield intriguing compounds that could be developed into drugs. Exploring the natural products from these bacteria holds the promise of discovering novel compounds with remarkable bioactivities.