Joshua Madu

Date of Award

Fall 2022

Document Type

Open Access Thesis


Chemistry and Biochemistry

First Advisor

Li Jie


Microbial resistance to therapeutic drugs is a global challenge and one of the biggest threats facing humanity. In keeping to a balance of defense and survival, microorganisms produce a plethora of secondary metabolites with wide spectrum of biological activity and structural variation that help them survive and out compete others hence can serve as sources of novel drugs to combat multi drug resistant (MDR) microbes. The current study explored the antimicrobial activity of a novel alkyl tetramate and its homologues produced by Streptomyces davawensis (DSM101723). To investigate this role, the molecule was isolated from the growth culture of Streptomyces davawensis and purified using a combination of open column chromatography and high-performance liquid chromatography. The antimicrobial activity of the purified molecule was evaluated in vitro against antibiotic resistant bacteria and fungi. The minimal inhibitory concentration (MIC) of the purified molecule against the test organisms were assessed using microdilution method. The results obtained indicates that the isolated molecules were active against Bacillus subtilis and Enterococcus faecium bacteria but not against Staphylococcus aureus and Pseudomonas aeruginosa and the tested fungi. The molecules exhibited a minimal inhibitory concentration of 6.25–12.50 µg/mL against Bacillus subtilis 168IAI and Enterococcus faecium. The molecules did not show synergistic effect when combined with commercial antibiotics. These results suggest a potential antimicrobial application of the molecule.


© 2022, Joshua Madu

Available for download on Sunday, December 15, 2024

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