Actinomycetes are virtually unlimited sources of novel compounds with many therapeutic applications
and hold a prominent position due to their diversity and proven ability to produce novel bioactive
compounds. There are more than 22,000 known microbial secondary metabolites, 70% of which are
produced by actinomycetes, 20% from fungi, 7% from Bacillus spp. and 1–2% by other bacteria. Among the
actinomycetes, streptomycetes group are considered economically important because out of the approximately
more than 10,000 known antibiotics, 50–55% are produced by this genus. The ecological role
of actinomycetes in the marine ecosystem is largely neglected and various assumptions meant there
was little incentive to isolate marine strains for search and discovery of new drugs. The search for and
discovery of rare and new actinomycetes is of significant interest to drug discovery due to a growing
need for the development of new and potent therapeutic agents. Modern molecular technologies are
adding strength to the target-directed search for detection and isolation of bioactive actinomycetes, and
continued development of improved cultivation methods and molecular technologies for accessing the
marine environment promises to provide access to this significant new source of chemical diversity with
novel/rare actinomycetes including new species of previously reported actinomycetes.