Antimicrobial endophytic fungal assemblages inhabiting bark of Taxus baccata L. of Indo-Burma mega biodiversity hotspot

Abstract

Fungal endophytes were isolated from inner bark of Taxus baccata L., an important source of potent anticancer drug taxol. Bark samples were collected from two locations of Arunachal Pradesh, India, part of the IndoBurma mega biodiversity hotspot, during two seasons i.e. monsoon and winter. Altogether 77 fungal strains representing 18 genera were isolated from T. baccata bark during the present investigation. The colonizing frequency was recorded as 38.5% and the fungal community comprised of 78% of Hyphomycetes, 5.2% of Coelomycetes, 2.6% of Zygomycetes and Ascomycetes and 9.1% of sterile mycelia. Most common and frequently isolated genera were Fusarium, Penicillium and Aspergillus. Simpson and Shannon diversity indices indicated higher species diversity during monsoon than during winter seasons irrespective of the locations. The two locations harbored 5 to 37 endophyte species and the similarity index was low during winter and high during monsoon. Ethyl acetate extract of fermentation cultures of these fungi were tested for their antimicrobial activity against a panel of human pathogenic Gram-positive and Gram-negative bacteria and fungi. Fifteen fungal isolates out of the isolated strains displayed antimicrobial activity. An endophytic fungus, identifi ed as Fusarium sp. displayed signifi cant antimicrobial activity against all the test pathogens.

Endophytic fungi associated withTaxus fuana(West Himalayan Yew) of Pakistan: potential bio-resources for cancer chemopreventive agents

“…However, none of the previous studies report it as an endophyte associated with the Taxus plant species. Consistent with earlier reports from Taxus chinensis (Zhou et al 2009;Tayung & Jha 2010), we also identified the NFW6 isolate as a strain of Mucor hiemalis. NFW8 was identified as Chaetomium which resides within various plants such as Curcuma wenyujin, Viguiera robusta and Taxus globosa (Momesso et al 2008;Wang et al 2010;Soca-Chafre et al 2011).…”

“…It is well established that endophytes are capable of producing remarkable cancer chemotherapeutic agents (Tayung & Jha 2010;Cragg & Pezzuto 2015). This investigation of biological activities mediated by endophytic fungi isolated from Taxus fuana indicates their diverse potential for the generation of bioactive metabolites.…”

Annulohypoxylonsp. strainMUS1, an Endophyte isolated fromTaxus wallichianaZucc. produces Taxol and Other Bioactive Metabolites

“…Recently, it was reported that crude extracts obtained with ethyl acetate from a fermented broth of Fusarium sp. isolated from T. baccata showed significant antimicrobial activity against all pathogens tested (i.e., Bacillus subtilis, Staphylococcus epidermis, Staphylococcus aureus, Klebsiella pneumoniae, Shigella flexneri, Escherichia coli, Candida albicans , and Candida tropicalis ) [33]. Similarly, among the 16 endophytic fungi isolated during our study, Annulohypoxylon sp.…”

The first Taxus rhizosphere microbiome revealed by shotgun metagenomic sequencing

“…For example, a Taxol‐producing endophyte induces transcription of genes encoding a redundant fungicide pathway in its host Taxus , and prevents colonization of its fungal competitors at minimal metabolic cost. Fifteen fungal isolates from T. baccata displayed antimicrobial activity . Perenniporia tephropora , an endophytic fungus of T. mairei , had strong anti‐ Pyricularia oryzae activity and produced the cytotoxic metabolites .…”