In: Sydowia 77, (2025): 231-243; ISSN 0082-0598, DOI 10.12905/0380.sydowia77-2025-0231, Published online on December 12, 2024

In vitro characterization of fungal isolates from soil as a potential fungal-based biostimulant for suppressing the growth of Ganoderma boninense as well as enhancing oil palm growth

Muhammad Salahudin Kheirel Anuar, Amalia Mohd Hashim, Chai Ling Ho, Mui-Yun Wong, Shamala Sundram, Noor Baity Saidi & Mohd Termizi Yusof,*

1 Department of Microbiology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, UPM 43400
Serdang, Selangor, Malaysia
2 Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia,
UPM 43400 Serdang, Selangor, Malaysia
3 Department of Plant Protection, Faculty of Agriculture, Universiti Putra Malaysia, UPM 43400 Serdang, Selangor, Malaysia
4 Biology Research Division, Malaysian Palm Oil Board, 43000 Kajang, Selangor, Malaysia

* e-mail: mohdtermizi@upm.edu.my

Anuar M.S.K.A., Hashim A.M., Ho C.L., Wong M.Y., Sundram S., Saidi N.B. & Yusof M.T. (2025) In vitro characterization of
fungal isolates from soil as a potential fungal-based biostimulant for suppressing the growth of Ganoderma boninense as well as
enhancing oil palm growth. – Sydowia 77: 231–243.

Oil palm crops play a crucial role in economic growth and food security for many countries but are susceptible to Ganoderma
boninense (Gb), which causes basal stem rot (BSR). Despite the use of biological control, the diseases have not been limited. Biostimulants
are substances that promote plant growth, and some microbial-based biostimulants with biocontrol functions have
been shown to be useful in mitigating biotic stress. Through in vitro conditions, this study characterizes the ability of fungal
isolates to suppress Gb and exhibit plant growth-promoting traits. Among nineteen isolates, six exhibited significant antagonistic
activity against Gb PER71 in dual culture and Poison food agar assays. Molecular identification revealed that the six fungal
isolates belonged to the genus Mucor, Aspergillus, Xenomyrothecium, Acrophialophora and Trichoderma. All isolates were subjected
to determining plant growth-promotion (PGP), including indole acetic acid (IAA) and ammonia productions, phosphate
solubilization, hydrogen cyanide (HCN) and catalase activity. Overall, all isolates have shown at least three PGP traits. Through
API® ZYM analysis, the fungal isolates were revealed to have phosphoric hydrolase, ester hydrolase, peptide hydrolase and glycosidase
activities. This study suggests that fungal isolates are an excellent candidate for developing potential fungal-based biostimulants
against Gb and promote plant growth in oil palm.

Keywords: antagonistic activity, microbial-based biostimulant, soil fungi.