Marine <Emphasis Type="Italic">Streptomyces</Emphasis> as a novel source of bioactive substances

Marine actinobacteria are the most economically as well as biotechnologically valuable prokaryotes. Representative genera of marine actinobacteria include Actinomadura, Aeromicrobium, Dietzia, Gordonia, Marinophilus, Micromonospora, Nonomuraea, Rhodococcus, Saccharomonospora, Saccharopolyspora, Salinispora, Streptomyces, Solwaraspora, Williamsia, Verrucosispora and several others. Among the genera of marine actinobacteria, the genus Streptomyces is represented in nature by the largest number of species and varieties, which differ greatly in their morphology, physiology, and biochemical activities. Marine Streptomyces occur in different biological sources such as fishes, molluscs, sponges, seaweeds and mangroves, besides seawater and sediments. In this review an evaluation is made on the present state of research on marine Streptomyces and its perspectives. The highlights include the production of metabolites such as antibiotics, anticancer compounds, enzymes, enzyme inhibitors and pigments by marine Streptomyces and their application as single cell protein and as probiotics in aquaculture. The marine environment contains a wide range of distinct Streptomyces that are not present in the terrestrial environment. With increasing advancement in science and technology, there would be greater demands in future for new bioactive compounds synthesised by Streptomyces from various marine sources.