Fungal Endophytes: An Accessible Natural Repository for Discovery of Bioactive Compounds

Microorganisms are proficient synthesizers of natural product molecules that are often bioactive and a source of various antibiotics and other pharmaceutical agents. The demand for new bioactive molecules is ever-increasing due to the emergence of new diseases, novel pathogens, and drug-resistant microbes. It is imperative to extend our search for molecules with novel bioactivities from unique and unexplored niches. Since the discovery of microbial Taxol (1), from a fungus inhabiting the tissues of Taxus brevifolia, endophytes, the microbes living within the plant tissues in mutualistic associations, have become an important source for the discovery of bioactive molecules. Since the endophytic associations are plant-specific, each plant forms a unique niche for the accumulation of a specific set of microbial species. The endophytes also pass through various stages of evolution within the plant system to evolve their natural product arsenal. Consequently, numerous plants are being analysed for the isolation and characterization of their endophytes for bioactive molecules and enzymes. Here, we report the progress of research and the current status of endophyte biology and biochemistry for the production of bioactive natural products.