Endophytic microorganisms of the tropical savannah: A promising source of bioactive molecules

Abstract

The Brazilian tropical savannah, known as the "Cerrado", is comprised of rich and characteristic flora, which makes it one of the 25 most important terrestrial biodiversity hotspots on the planet. This ecosystem is characterized by seasonal weather with annual precipitation that varies between 1200 and 1800 mm and a dry season that occurs during 5-6 months a year. This Brazilian savannah is a typical mosaic biome characterized by plants that can be endemic to this niche and several plant species that have medicinal properties and great pharmaceutical relevance. Although interest has increased in the microbial biodiversity associated with medicinal plants, the diversity, taxonomic composition, and biotechnological potential of endophytic microorganisms associated with these tropical plants from the savannah remain unclear. Plant-associated microorganisms such as endophytes are subjected to constant metabolic and environmental interactions, and these organisms should produce more secondary metabolites. These molecules are characterized by their diverse chemical structures and may be of use due to the wide range of their bioactivity against pathogens. The native plants of the Brazilian savannah are commonly used to treat skin diseases, ulcers, anemia, diabetes, malaria, inflammatory reactions, and hepatic diseases, and this medicinal flora has been used as folk medicine by different people as an alternative to high-priced pharmaceutical drugs. However, only a few of the medicinal Brazilian plants have been studied as a source of bioactive endophytic microbial communities. Several endophytes are important for microbial activities such as antibiotic capability against Gram-positive and Gram-negative bacteria, antifungal, antibiotic resistance, enzyme production, antitumor activity, and anti-Leishimania activity. The exploration of endophytes from new host hosts is important for assessing the potential of these microorganisms in different application areas and for emphasizing the potential of natural compounds that can be used in clinics and the pharmaceutical industry.