Identification of Endophytic Natural Products with Antibacterial and Antinematodal Activity

Jasmine Gonzalez, Yuting Wang, Rebecca A. Butcher

University of Florida-Gainesville, Florida

Endophytic fungi are microorganisms that can be found on the living tissue of nearly every plant on earth. These microbes are exceptional sources of bioactive natural products that hold potential for exploitation in modern medicine, agriculture, and industry. Identification of novel natural products with antibacterial activity or nematode activity is the objective of this project. A collection of 150 different plants and 245 endophytic fungi were gathered for the experiment. Pure cultures of the endophytes were isolated and then cultured in liquid media. Subsequently, organic solvent extractions were performed to generate crude extracts of the natural products from the endophytes. To determine which extracts contained bioactive compounds, they were examined with two bioassays. The antibiotic screening bioassay used the gram-negative bacteria E. coli BAS849 strain, which has increased outer membrane permeability. Of the 165 extracts tested for antibacterial activity, 28 demonstrated inhibition of bacteria growth. Meanwhile, the crude extracts were also tested through a nematode assay. The nematodes, C. elegans, were used as a model organism for the analysis of this bioassay. The worms were incubated for 3 days and then observed under a microscope to examine their state. 20 of the 165 extracts evaluated, showed a positive bioactivity. The active compounds were purified via high performance liquid chromatography (HPLC) and other analytical methods. Through the identification of possible bioactive compounds from this project, our findings may provide novel natural products which might serve as potential antibiotics and/or antinematode drugs in the future.