Screening & Purification of Antimicrobial Compounds from Australian Marine & Freshwater Fungi

Author: Nishansala Madhumali Fernando Mahamalage

  • Thesis download: available for open access on 10 Jan 2026.

Mahamalage, Nishansala Madhumali Fernando, 2023 Screening & Purification of Antimicrobial Compounds from Australian Marine & Freshwater Fungi, Flinders University, College of Medicine and Public Health

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Abstract

Antibiotics are the most common medical approach in infectious disease treatments. The discovery of antibiotics reduced the mobility and mortality rates of the world and increased the life expectancy of humans. However, due to the inappropriate use of antibiotics over time, antibiotic resistance emerged among pathogenic bacteria leading to a loss of antibiotic effectiveness. Immediate actions are required for novel antibiotics against the antibiotic resistance crisis. Among the different possible sources, fungi are considered one of the potential sources of novel antibiotic compounds. Freshwater and marine fungi are recorded as the developing study area on novel bioactive compounds. This study aimed to screen the antimicrobial compounds from Australian freshwater and marine fungi.

Twenty-eight freshwater fungi and eight marine fungi which were isolated from four locations in Australia were screened for their antimicrobial activity on four agar medium as primary screening and solid-state fermentation using jasmine rice, mung bean, and chickpea as secondary screening and in liquid culture fermentation. One marine fungus GIB19A, and six freshwater fungi MR33A, SCC31A, SCC45A, FRB29A, FRB17A, and FRW2A were selected for their significant antimicrobial activity. All seven strains exhibited the narrow-spectrum activity against Gram-positive bacteria and GIB19A and FRB29A showed broad-spectrum activity against Gram (-) bacteria. Three strains SCC31A, SCC45A, and GIB19A were grown on a large scale, and the resulting crude extracts were purified using column chromatography and preparative thin-layer chromatography. Three purified antimicrobial compounds were obtained as one from each strain. Compounds will be subjected to structure elucidation as the future direction of the study.

Keywords: Antimicrobial compounds, Marine fungi, Freshwater fungi

Subject: Biotechnology thesis

Thesis type: Masters
Completed: 2023
School: College of Medicine and Public Health
Supervisor: Chris Franco