In: Sydowia 79, (2027): 43-57; ISSN 0082-0598, DOI 10.12905/0380.sydowia79-2027-0043, Published online on July 13th, 2026

Bioprospecting the biocontrol potential of fungal endophytes of Acorus calamus: a focus on siderophore and enzymatic activity

Prabha Parki, Himani Verma & Kapil Khulbe

Department of Botany, D.S.B. Campus, Kumaun University, Nainital-263001, Uttarakhand, India

* e-mail: kapilkhulbe@gmail.com

Parki P., Verma H. & Khulbe K. (2025) Bioprospecting the biocontrol potential of fungal endophytes of Acorus calamus: a focus on siderophore and enzymatic activity. – Sydowia 79: 43–57.

The leaves and rhizomes of Acorus calamus were studied for endophytic fungi. Microscopic and molecular techniques identified the fungi as Cladosporium sphaerospermum (CS) and Plectosphaerella sp. (Ps). Ps demonstrated enzymatic activity for cellulase, pectinase, protease, laccase, and tyrosinase, whereas CS for cellulase, pectinase, and tyrosinase. Both isolates showed the potential to produce siderophores. Dual culture and well diffusion tests of crude extracts were performed against Fusarium oxysporum and Botrytis cinerea. CS exhibited maximum percent inhibition of 40.2±0.76 against F. oxysporum in the dual culture assay and 72.6±1.7 in the well diffusion assay. Ps showed a maximum inhibition of 25.9±1.7 against F. oxysporum in dual culture and 54.1±2.4 against B. cinerea in the well diffusion assay. Antibacterial activity was assessed against four phytopathogenic bacteria, i.e., Xanthomonas phaseoli, Xanthomonas campestris, Ralstonia solanacearum, and Agrobacterium tumefaciens. In the well
diffusion assay, CS exhibited the highest inhibition zone against X. phaseoli and A. tumefaciens, while Ps was most effective against X. campestris. The crude extracts of CS had a maximum inhibitory power of 6 mm against A. tumefaciens with a MIC value of 125 µg l-1. In the disk diffusion method, CS also showed the greatest inhibition against X. phaseoli and A. tumefaciens, while Ps excelled against X. campestris.

Keywords: Endophytic fungi, extracellular enzymes, antimicrobial, siderophore