Investigation of Antimicrobial Activity and Identification of Bioactive Volatile Metabolites of Jute Endophytic Fungus Aspergillus flavus
Farhana Tasnim Chowdhury1, Mrinmoy Sarker1, Muhammad Saiful Islam2, Husna Parvin Nur2, Mohammad Riazul Islam1, Haseena Khan1*
1Molecular Biology Laboratory, Department of Biochemistry and Molecular Biology, University of Dhaka, Dhaka-1000; 2Fibre and Polymer Research Division, Bangladesh Council of Scientific and Industrial Research (BCSIR), Dhaka-1205.
ABSTRACT: Jute, a well-known tropical plant with high fibre quality and medicinal importance, is extensively used in south Asian region.
The present study was intended to isolate, identify, and evaluate the biological properties of an endophytic fungus of jute and also to decipher
the plethora of volatile organic compounds it produces. The target endophyte Aspergillus flavus was identified by morphological analysis and by
sequencing the internal transcribed spacer (ITS) region. Both extracellular and intracellular fungal extract exhibited broad spectrum antibacterial
activity against six opportunistic human pathogenic bacteria (Lactococcus lactis NCTC 497, Bacillus subtilis168, Staphylococcus aureus SG511,
Staphylococcus carnosusTM300, Bacillus pseudomycoides DSM 12442 and Escherichia coli BL21 (DE3)). The ethyl acetate extract displayed greater
antimicrobial activity against all the tested pathogens than the methanolic extract. Further, profiling of total volatile organic compounds of
the fermented extract using Gas Chromatograph-Mass Spectrometry (GC-MS) confirmed the presence of a variety of bioactive components. The major
compounds identified in GC-MS analysis included 4-nitrobenzoic acid, 3-chlorophenyl ester (27.23%) and (+)-salsolidine (21.82%) which are nitrobenzoate
and alkaloid class of compounds respectively and are known to have antimicrobial potential. In conclusion, the endophytic A. flavus isolated from
jute can be seen as a commercial and potential natural resource with varied therapeutic and biological activities. However, the features of these
compounds and the mechanisms of action should be further studied to understand their specific activity.
KEYWORDS: Jute, endophyte, Aspergillus flavus, antimicrobial activity, GC-MS.