Title An in vitro study of the antifungal activity of Trichoderma virens 7b and a profile of its non-polar antifungal components released against Ganoderma boninense
Author Lee Pei Lee Angel1,2, Mohd Termizi Yusof1, Intan Safinar Ismail3,4, Bonnie Tay Yen Ping5, Intan Nur Ainni Mohamed Azni2, Norman Hj Kamarudin2, and Shamala Sundram2*
Address 1Department of Microbiology, Faculty of Biotechnology and Biomolecular Sciences University Putra Malaysia, 43400 Serdang, Selangor, Malaysia, 2Biology Research Division, Malaysian Palm Oil Board, 43000 Kajang, Selangor, Malaysia, 3Department of Chemistry, Faculty of Science; Laboratory of Natural Products, University Putra Malaysia, 43400 Serdang, Selangor, Malaysia, 4Institute of Bioscience, University Putra Malaysia, 43400 Serdang, Selangor, Malaysia , 5Advanced Oleochemical Technology Division, Malaysian Palm Oil Board, 43000 Kajang, Selangor, Malaysia
Bibliography Journal of Microbiology, 54(11),732-744, 2016,
DOI 10.1007/s12275-016-6304-4
Key Words Ganoderma boninense, endophytic Trichoderma, non-polar, antifungal activities, siderophore
Abstract Ganoderma boninense is the causal agent of a devastating disease affecting oil palm in Southeast Asian countries. Basal stem rot (BSR) disease slowly rots the base of palms, which radically reduces productive lifespan of this lucrative crop. Previous reports have indicated the successful use of Trichoderma as biological control agent (BCA) against G. boninense and isolate T. virens 7b was selected based on its initial screening. This study attempts to decipher the mechanisms responsible for the inhibition of G. boninense by identifying and characterizing the chemical compounds as well as the physical mechanisms by T. virens 7b. Hexane extract of the isolate gave 62.60% ± 6.41 inhibition against G. boninense and observation under scanning electron microscope (SEM) detected severe mycelial deformation of the pathogen at the region of inhibition. Similar mycelia deformation of G. boninense was observed with a fungicide treatment, Benlate® indicating comparable fungicidal effect by T. virens 7b. Fraction 4 and 5 of hexane active fractions through preparative thin layer chromatography (P-TLC) was identified giving the best inhibition of the pathogen. These fractions comprised of ketones, alcohols, aldehydes, lactones, sesquiterpenes, monoterpenes, sulphides, and free fatty acids profiled through gas chromatography mass spectrometry detector (GC/MSD). A novel antifungal compound discovery of phenylethyl alcohol (PEA) by T. virens 7b is reported through this study. T. virens 7b also proved to be an active siderophore producer through chrome azurol S (CAS) agar assay. The study demonstrated the possible mechanisms involved and responsible in the successful inhibition of G. boninense.