Date of Award


Document Type


Degree Name

Master of Science (MS)


College of Science and Mathematics



Thesis Sponsor/Dissertation Chair/Project Chair

Lee H. Lee

Committee Member

Sandra Adams

Committee Member

Ann Marie DiLorenzo


In a world where microorganisms outnumber humans, the need for novel antimicrobial agents is crucial to human health. Multi-drug resistant strains of microorganisms have caused a worldwide crisis. Recent research studies on antimicrobials are centered on natural compounds. Natural resources such as green tea have been studied for the past several decades for their antimicrobial, anti-cancerous, anti-inflammatory and numerous other beneficial properties. This particular study focuses on the effects of green tea polyphenols (GTP) and their derivatives, Lipophilic Tea Polyphenol (LTP), Epigallocatechin gallate (EGCG), and Epigallocatechin gallate Stearate (EGCG-Stearate) as antimicrobial agents, antibiotic synergism agents, inhibitors of spore formation and biofilm formation. From initial studies of viable count, staining techniques, to growth curves and disk diffusion studies, the green tea polyphenols are applied to select microorganisms. The selected bacteria separated into Gram negative bacteria: Escherichia coli, Pseudomonas aeroginosa, Serratia marcescens, ampicillin resistant Escherichia coli and Enterobacter aerogenes; Gram positive bacteria: Bacillus megaterium, Staphylococcus aureus, and Staphylococcus epidermidis, and acid-fast bacteria: Mycobacterium smegmatis were used in these experiments. Kirby Bauer disk diffusion experiments revealed all polyphenols synergistically work with more than three antibiotics for E.coli, E. aerogenes and S. epidermidis. 1% GTP and 1% EGCG have no synergistic effect on S. marcescens but 1% EGCG-Stearate and 1% LTP do have a synergistic inhibition. Only 1% EGCG-Stearate had a synergistic effect with B. megaterium. For growth inhibition 1% EGCG and 1% EGCG-Stearate were able to inhibit the growth of a majority of the microorganisms alone without ampicillin to a certain extent. In the presence of ampicillin most of the growths are completely inhibited. Spore study revealed 10% LTP treatment had a 91% inhibition of sporulation compared to control spores. 10% GTP treatment resulted in an average of 64.1% inhibition. 10% EGCG resulted in a 100% inhibition compared to 10% EGCG-Stearate, which showed 79% inhibition. These broad studies of the endless benefits of green tea polyphenols give rise to many medicinal implications. From these results, it can be concluded that LTP, GTP, EGCG and EGCG-Stearate are antimicrobial agents with EGCG and EGCGStearate being the most effective agent.

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