title: Biotechnological potential of endophytic actinomycetes associated with Asteraceae plants: isolation, biodiversity and bioactivities.
abstract: Endophytic actinomycetes from five Asteraceae plants were isolated and evaluated for their bioactivities. From Parthenium hysterophorus, Ageratum conyzoides, Sonchus oleraceus, Sonchus asper and Hieracium canadense, 42, 45, 90, 3, and 2 isolates, respectively, were obtained. Of the isolates, 86 (47.2 %) showed antimicrobial activity. Majority of the isolates were recovered from the roots (n = 127, 69.7 %). The dominant genus was Streptomyces (n = 96, 52.7 %), while Amycolatopsis, Pseudonocardia, Nocardia and Micromonospora were also recovered. Overall, 36 of the 86 isolates were significantly bioactivity while 18 (20.9 %) showed strong bioactivity. In total, 52.1 and 66.6 % showed potent cytotoxicity and antioxidant activities. The LC50 for 15 strains was <20 μg/ml. Compared to the ascorbate standard (EC50 0.34 μg/ml), all isolates gave impressive results with notable EC50 values of 0.65, 0.67, 0.74 and 0.79 μg/ml.
authors.affiliation: Department of Microbiology and Molecular Genetics, University of the Punjab, Quaid-e-Azam Campus, Lahore, 54590, Punjab, Pakistan, rabiatanvir@hotmail.com.
authors.forename: Rabia
authors.initials: R
authors.lastname: Tanvir
authors.forename: Imran
authors.initials: I
authors.lastname: Sajid
authors.forename: Shahida
authors.initials: S
authors.lastname: Hasnain
mesh_terms: D039903:Actinobacteria / Q000145:classification / Q000302:isolation & purification* / Q000502:physiology; D000898:Antibiosis; D019659:Asteraceae / Q000382:microbiology*; D044822:Biodiversity; D001709:Biotechnology / Q000379:methods*; D060026:Endophytes / Q000145:classification / Q000302:isolation & purification* / Q000502:physiology