title: Biological Evaluation of Endophytic Fungus Chaetomium sp. NF15 of Justicia adhatoda L.: A Potential Candidate for Drug Discovery.
abstract: BACKGROUND
  The endophytes of medicinal plants, such as Justicia adhatoda L., represent a promising and largely underexplored domain that is considered as a repository of biologically active compounds.
  
  
  OBJECTIVE
  The aim of present study was isolation, identification, and biological evaluation of endophytic fungi associated with the J. adhatoda L. plant for the production of antimicrobial, antioxidant, and cytotoxic compounds.
  
  
  METHODS
  Endophytic fungi associated with the J. adhatoda L. plant were isolated from healthy plant parts and taxonomically characterized through morphological, microscopic, and 18S rDNA sequencing methods. The screening for bioactive metabolite production was achieved using ethyl acetate extracts, followed by the optimization of different parameters for maximum production of bioactive metabolites. Crude and partially purified extracts were used to determine the antimicrobial, antioxidant, and cytotoxic potential.
  
  
  RESULTS
  Out of six endophytic fungal isolates, Chaetomium sp. NF15 showed the most promising biological activity and was selected for detailed study. The crude ethyl acetate extract of NF15 isolate after cultivation under optimized culture conditions showed promising antimicrobial activity, with significant inhibition of the clinical isolates of Staphylococcus aureus (87%, n=42), Pseudomonas aeruginosa (> 85%, n = 41), and Candida albicans (62%, n = 24).
  
  
  CONCLUSIONS
  The present study confirms the notion of selecting endophytic fungi of medicinal plant Justicia for the bioassay-guided isolation of its bioactive compounds, and demonstrates that endophytic fungus Chaetomium sp. NF15 could be a potential source of bioactive metabolites.
authors.affiliation: Department of Microbiology, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan; Department of Biotechnology, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan.
authors.forename: Nighat
authors.initials: N
authors.lastname: Fatima
authors.affiliation: Department of Microbiology, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan.
authors.forename: Usman
authors.initials: U
authors.lastname: Mukhtar
authors.affiliation: Department of Pharmacy, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan.
authors.lastname: Ihsan-Ul-Haq
authors.affiliation: Department of Microbiology, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan.
authors.forename: Muneer
authors.initials: M
authors.lastname: Ahmed Qazi
authors.affiliation: Department of Microbiology, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan.
authors.forename: Muniba
authors.initials: M
authors.lastname: Jadoon
authors.affiliation: Department of Microbiology, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan.
authors.forename: Safia
authors.initials: S
authors.lastname: Ahmed
keywords: Antimicrobial; Antioxidant; Chaetomium sp.; Endophytes; Justicia adhatoda L.