Isolation and molecular identification of endophytic fungi associated with Ziziphora tenuior L. and their biological potential

Abstract

Endophytic fungi are microorganisms found in the inter- or intracellular compartments of plant tissue and can improve plant performance through a variety of mechanisms. They are considered a potential source of biological compounds such as terpenoids, phenols, alkaloids, and fatty acids, which are extensively used in various industries. The present study was conducted to investigate the molecular identification, fatty acid profile analysis, and antibacterial properties of endophytic fungi isolated from the aerial parts of Ziziphora tenuior (L.). Phylogenetic analysis was performed based on the Internal Transcribed Spacer (ITS) region and seven fungal isolates were classified into six genera as follows: Acremonium, Aspergillus, Cladosporium, Neocamarosporium, Alternaria, and Stemphylium. The analysis of fatty acids in the n-hexane extracts of Z. tenuior and mycelia of endophytic fungi with GC device showed that the amount of fatty acids is between 32.7-55.5%. A. infectoria (55.5%) and A. ochraceus (54.3%) had the highest amount of fatty acids among studied isolated. γ–Linolenic acid (C18:3), linoleic acid (C18:2), palmitic acid (C16:0), stearic acid (C18:0), and oleic acid (C18:1) were the main fatty acids. Also, the n-hexane extract of A. ochraceus showed antibacterial activity against Bacillus cereus, B. subtilis, Escherichia coli, and Pseudomonas aeruginosa. The results reveal that endophytic fungi are a source of natural bioactive metabolites, which could be applied in different industries. This is the first report of endophytic fungi diversity in Z. tenuior, which provides knowledge on their future use on biotechnological processes.