title: Bioactive Potential of Actinomycetes from Less Explored Ecosystems against Mycobacterium tuberculosis and Other Nonmycobacterial Pathogens.
abstract: Bioactive potential of actinomycetes isolated from certain less explored Indian ecosystems against Mycobacterium tuberculosis and other nonmycobacterial pathogens was investigated. Actinomycetes were isolated from the soil samples collected from desert, coffee plantation, rubber forest, and hill area and their cultural and micromorphological characteristics were studied. Crude extracts were prepared by agar surface fermentation and tested against M. tuberculosis isolates by luciferase reporter phage (LRP) assay at 100 µg/mL. Activity against nonmycobacterial pathogens was studied by agar plug method. Totally 54 purified cultures of actinomycetes including 43 Streptomyces and 11 non-Streptomyces were isolated. While screening for antitubercular activity, extracts of 39 actinomycetes showed activity against one or more M. tuberculosis isolates whereas 27 isolates exhibited antagonistic activity against nonmycobacterial pathogens. In particular crude extracts from sixteen actinomycete isolates inhibited all the three M. tuberculosis isolates tested. Findings of the present study concluded that less explored ecosystems investigated in this study are the potential resource for bioactive actinomycetes. Further purification and characterization of active molecule from the potential extracts will pave the way for determination of MIC, toxicity, and specificity studies.
authors.affiliation: Centre for Drug Discovery and Development, Sathyabama University, Chennai, Tamil Nadu 600 119, India.
authors.forename: Radhakrishnan
authors.identifier: 0000-0002-2689-6832
authors.initials: R
authors.lastname: Manikkam
authors.affiliation: Department of Microbiology, Periyar University, Salem, Tamil Nadu 636 011, India.
authors.forename: Gopikrishnan
authors.initials: G
authors.lastname: Venugopal
authors.affiliation: Department of Bacteriology, National Institute for Research in Tuberculosis, Chennai, Tamil Nadu 600 031, India.
authors.forename: Balaji
authors.initials: B
authors.lastname: Subramaniam
authors.affiliation: Department of Microbiology, Periyar University, Salem, Tamil Nadu 636 011, India.
authors.forename: Balagurunathan
authors.initials: B
authors.lastname: Ramasamy
authors.affiliation: Centre for Drug Discovery and Development, Sathyabama University, Chennai, Tamil Nadu 600 119, India.
authors.forename: Vanaja
authors.identifier: 0000-0003-3862-6482
authors.initials: V
authors.lastname: Kumar