Association for Biology Laboratory Education

Antibiotic Properties of Spices
 

Sasha Balcazar, Maria Burnatowska-Hledin, Kathy Winnett-Murray, & Lori Hertel

Tested Studies in Laboratory Teaching, 2016, Volume 37

Abstract

Spices have been used for centuries to make food taste better, add nutrients, and retard spoilage. Scientists have recently proposed that spices may also kill micro-organisms, inhibit their growth, or suppress their production of toxins, implying that the development of spice use in ethnic cuisines may have been used historically to protect consumers from illness caused by pathogens (Sherman and Flaxman 2001). A variety of laboratory exercises designed to test spices for antimicrobial effects have been developed. Few of these emphasize evolutionary themes, and even fewer capitalize on the rich potential that a multitude of unique combinations of spices, microbes, solvents, and preparations can provide for an array of student-directed hypothesis-testing. Worldwide, there is tremendous variability in the use of different spices. This suggests that, if there is a relationship between spice use and antimicrobial benefits, this relationship has been realized multiple times in different cultures in the development of ethnic cuisines. This theme is inherently intriguing to many undergraduates, who may be curious about “who” uses what types of spices, and why. In this lab, we allow students to construct an investigation, including submission of a group research proposal, arising from their own personal interest in certain spices. We equip students with a standard protocol (the diffusion disk assay) to test their own unique hypotheses; the shared protocol facilitates lab management, resource use, and interpretation of outcomes, while allowing for a significant range of student-generated experiments. Students are also encouraged to compare the effectiveness of their spice extracts with other antibiotics (e.g. penicillin, erythromycin) on a target microbe (either Escherichia coli or Staphylococcus epidermidis). An extension allows students to document evidence of the microbial response through mutations – evidence of the evolution of antimicrobial resistance.

Keywords:  microbiology, student-designed laboratory, antibiotic, antimicrobial, spices, diffusion disk assay, evolutionary response, microbial inhibition

Boston University (2015)