Enhancing the Discovery of Bioactive Secondary Metabolites From Fungal Endophytes Using Chemical Elicitation and Variation of Fermentation Media

• DOI: 10.3389/fmicb.2022.898976
• Publication Date: 2022-06-06T06:56:47Z
• Authors: Martin Muthee Gak...; Kuan Chieh Ching; Madhaiyan Munusamy; Mario Wibowo; Zhao-Xun Liang; Yoganathan Kanaga...; Siew Bee Ng
• Keywords: Chaetomium

Endophytic microorganisms are an important source of bioactive secondary metabolites. In this study, fungal endophytes obtained from A*STAR's Natural Product Library (NPL) and previously isolated different habitats Singapore were investigated for their diversity, antimicrobial, cytotoxic activities. A total 222 strains identified on the basis sequence analysis ITS region rDNA gene. The belong to 59 genera distributed in 20 orders. Majority (99%; 219 strains) phylum Ascomycota, while two belonged Basidiomycota, only one strain was Mucoromycota phylum. most dominant genus Colletotrichum accounting 27% all strains. Chemical elicitation using 5-azacytidine suberoylanilide hydroxamic acid (SAHA) variation fermentation media resulted discovery more Bioassay-guided isolation structure elucidation active constituents three prioritized strains: Lophiotrema sp. F6932, Muyocopron laterale F5912, tropicicola F10154, led a known compound; palmarumycin C8 five novel compounds; CP30, muyocopronol A-C tropicicolide. Tropicicolide displayed strongest antifungal activity against Aspergillus fumigatus with IC50 value 1.8 μg/ml but weaker Candida albicans presenting 7.1 μg/ml. Palmarumycin revealed best antiproliferative values 1.1 2.1 MIA PaCa-2 PANC-1 cells, respectively.