Antimicrobial Screening of Phytochemicals Produced by Albertan Invasive Weeds

Abstract

Antibiotic resistance has rendered many clinically-used antibiotics ineffective, creating an urgent need for new antimicrobial agents. Phytochemicals (secondary metabolites produced by plants) are produced in response to environmental stressors, and can inhibit the growth of bacteria, fungi and surrounding plants. Therefore, these phytochemicals offer an alternative source of antimicrobial compounds. The diversity and abundance of phytochemicals produced by plants can increase during the invasion of new habitats, making invasive weeds strong candidates for antimicrobial discovery. Despite this increase in phytochemical production, invasive plant species are often overlooked in favour of medicinal and edible plants, and few studies have characterized their antimicrobial activity. In this research, we used successive Soxhlet extractions with hexane, ethyl acetate, and methanol to extract the phytochemicals from Albertan invasive weed species collected from the Edmonton area. Using Kirby-Bauer disk diffusion assays, extracts were assessed for their ability to inhibit the growth of tester bacterial species including Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, and Staphylococcus aureus, which represent a range of common pathogens and bacterial types. Preliminary characterizations of extracts from multiple plant species, including common tansy (Tanacetum vulgare) and woolly burdock (Arctium tomentosum), showed promising inhibitory activity against several bacterial species, warranting further investigation. This study provides a starting point for further bioactivity and chemical characterizations of Albertan invasive weeds and highlights these invasive plant species as potential leads for the development of new antimicrobial treatments.

Department: Biological Sciences

Faculty Mentors: Dr. Kimberley Harcombe and Dr. Tina Bott