Bioautography of Nudibranch (Phyllidia varicosa) Associated Microbe Ethyl Acetate Metabolite Extract as Antibacterial Agent

Abstract

Antimicrobial resistance is a threat that can be combated by discovering new antimicrobials. Previous screening attempts by Badan Riset dan Inovasi Negara (BRIN)/ national research and innovation agency resulted in the discovery of a mold specimen with a broad-spectrum antimicrobial activity. Morphological observation of the specimen shows similarity to some species of mold belonging to Aspergillus and Penicillium genera which both contribute to more than half of all marine fungal isolate derived antibacterial. The mold itself is obtained during the screening process of Phyllidia varicosa, a nudibranch species that is an understudied screening target for antibacterial compounds. Additionally, there have been no previous studies conducted on the antibacterial effect of Phyllidia varicosa or any nudibranch mold symbiont nor information of media type used to grown the mold being able to induce antimicrobial production in mold sample, which becomes a point of novelty in this research. It is the aim of this proposal to gather data from ethyl acetate extraction and subsequent bioautography of the extract for identification of compound(s) responsible for eliciting this antibacterial activity. This thesis finds that antimicrobial activity of the specimen is a polar compound. However, the validity of the result is compromised with the coelution of several compounds in the active fraction and it is recommended for future assays to separate the methods used to fractionate the crude extract and antibacterial assay.