Actinomycetes as Continued Source of New Antibacterial Leads

Abstract

Early antibiotic discovery program has witnessed significant role of mainly Streptomyces in antibiotic/drug discovery program. Due to various constraints, both academic and industry levels, the discovery of new antibiotics with novel mode of action is drastically slowed down in the last three decades. Rapid development and spread of multidrug-resistant bacteria globally have reduced the utility and effectiveness of old antibiotics. Therefore, the discovery of novel antibacterial compounds is urgently needed to combat antimicrobial resistance. However, natural product-based academic research could prove to be a sustained mine of novel antimicrobial leads. According to an estimate among the bioactive compounds that have been obtained so far from microbes, 45% are produced by actinomycetes, 38% by fungi, and 17% by unicellular eubacteria. This has become possible because of great diversity of actinomycetes in different habitat and their extraordinary capacity to synthesize new antibiotics. The development in the screening strategies and the use of modern biochemical and molecular approaches have made possible to detect new compounds. In this chapter, we have focused on general characteristics of soil and marine actinomycetes and improved screening strategies adapted by various workers. A recent update is also provided to highlight the role of actinomycetes as the continued source of novel antibacterial lead compound and their future prospects.