GC-MS Analysis of Metabolites from Aspergillus tamarii and Trichoderma sp. Detected Promising Biological Compounds

Fifteen multicellula r fungi previously isola ted from rice paddies were evalua ted for their a ntibacterial activities aga inst test orga nisms using the aga r plug method. Only seven of the fungal isola tes showed activity aga inst the test orga nisms Escherichia coli, Bacillus cereus, a nd Staphylococcus aureus. These seven fungi were subsequently grown on yeast extract sucrose aga r (YES), pota to dextrose aga r (PDA), a nd Sa boura ud dextrose aga r (SDA) to determine their radial growth a nd time of sporula tion over a period of seven days. The fastest sporula tion was achieved by Penicillium funiculosum (three days), Aspergillus tamarii (five days), a nd Trichoderma sp. (six days). Spore suspensions (150 spores/mL) of these fungi were sepa ra tely inocula ted in 100 mL of Yeast Extract Broth (YEB), Pota to Dextrose Broth (PDB), a nd Sa boura ud Dextrose Broth (SDB), a nd cultured for 35 days in room tempera ture (24–27oC) a t sta tiona ry condition. Culture filtra tes were extracted with ethyl aceta te (1:1 v/v) a nd used for herbicidal assay using Vigna radiata a nd for gas chroma tography-mass spectrometry (GC-MS). No herbicidal activity was observed with wa ter as control. Compounds identified (>90% simila rity with Na tional Institute for Sta nda rds a nd Technology [NIST] libra ry) included bis (2-ethyl hexyl) phthala te (a ntifungal a nd a nti-infla mma tory), dehydromevalonic lactone (fragra nce production), benzene acetaldehyde (fragra nce production), a nd n-hexadeca noic acid (a nti-infla mma tory). Meta bolomics da ta provide the basis for future optimiza tion studies to genera te utiliza ble bioactive compounds.