Abstract

Emerging resistance to available antibiotics is one of the biggest problems of mankind. This problem brings a serious question to the researcher’s mind: What will be the next promising source of novel antimicrobial compounds to overcome drug resistance? Although many synthetic or modified chemical compounds can be used as a new source of the drug, nature is the richest and most versatile source of new antibiotics. Natural products and their derivatives are far more important in the discovery of new reliable sources of pharmaceuticals. We can use natural compounds and their derivatives to treat cancer, diabetes, and inflammatory and infectious diseases. Other reasons why natural compounds are a good choice for new drug discovery are their lesser side effects, skill to control the existence and development of diseases and potential to act against resistant strains of disease-forming microorganisms. A huge number of diversified chemical components of marine microorganisms, provide us with a rich and versatile source of biologically active components. But among this enormous microbial diversity, very few amounts have been explored till now. Marine microorganisms and their metabolites are reported as an effective and promising sources of new antibiotics or drugs that can act against various antibiotic-resistant strains of pathogenic microorganisms. Marine bacteria, fungi, and cyanobacteria provide numerous industrially useful bioactive components which further possess antibacterial, antifungal and antimycobacterial activities. There are many biotechnological methods and machines like biosensors which is used to detect and isolate useful target components from marine microorganisms. A slight modification in the chemical groups of marine microbes-derive bioactive compounds generates their new derivatives, mimetic and structural analogs that can serve as a novel drug against pathogenic microorganisms. Every structurally different molecule acts functionally with numerous biological activities against various pathogenic microorganisms. This criterion makes marine-derived products more valuable to us in this contemplative time of drug resistance. In this chapter, we discuss various metabolites of marine microorganisms (bacteria, fungi, actinomycetes, and cyanobacteria) having promising antimicrobial properties which could act as a potential natural source of drugs against pathogenic microorganisms.