The relationship between antibiotic compounds in wild plant extracts and environmental growing conditions – factors affecting the antimicrobial activity of Allium Ursinum L.

Abstract

In order to investigate how environmental factors affect plant antibiotic compounds, a literature review of plants with known antibiotic plant activity was carried out, and wild garlic (Allium ursinum L.) chosen as the model organism for the study. 168 individuals were collected from 7 sites across London and its suburban area alongside environmental variables measured for each. The samples were assayed against Bacillus subtilis to test antibacterial ability, and this data was compared to the environmental variables. LCMS of the samples was also performed to determine the amount of allicin and kaempferol in each sample, both of which are known to be active antimicrobial compounds. The study found that soil temperature had the strongest effect directly on bacteria concentration and both chemical compounds, affecting the enzymes involved with compound production. The sites’ proximity to roads, railways and public walkways also had a significant effect on antimicrobial activity, possibly caused by pollutants and heavy metals in the soil and atmosphere. The results of this project could be useful in the wider application of finding new natural antibiotics to be used in livestock feed, replacing environmentally-damaging medicines which are to be banned across Europe.