Abstract
This chapter discusses microbial secondary metabolism. Of the prodigious number of carbon compounds, many are materials produced by living organisms. They are termed “natural products” Natural products constitute a very large and diverse group of compounds that are hard to characterize. This chapter focuses on “secondary metabolites.” The chapter explored what secondary metabolites are; origin of this term; and the use of secondary metabolites in biological sciences. Modern organic chemistry began with the isolation and characterization of certain compounds from human body fluids and from plant and animal tissues. In the second half of the nineteenth century, the number of known metabolites increased almost exponentially. To organic chemists, these strange metabolites were simply “natural products” providing never ending challenges of structure determination and total synthesis. With the exception of pigments, the chemical diversity expressed in secondary metabolism is less obvious and therefore, more mysterious. This represents the beguiling and beautiful manifestations of genotypic differentiation that species have perfected during their evolutionary history.