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  3. Rare actinomycetes Nocardia caishijiensis and Pseudonocardia carboxydivorans as endophytes, their bioactivity and metabolites evaluation

Rare actinomycetes Nocardia caishijiensis and Pseudonocardia carboxydivorans as endophytes, their bioactivity and metabolites evaluation

  • Microbiol Res. 2016 Apr;185:22-35. doi: 10.1016/j.micres.2016.01.003.
Rabia Tanvir 1,  Imran Sajid 2,  Shahida Hasnain 3,  Andreas Kulik 4,  Stephanie Grond 5
Affiliations

Affiliations

  • 1 Department of Microbiology and Molecular Genetics, University of the Punjab, Quaid-e-Azam Campus, 54590, Lahore, Punjab, Pakistan; Institut fur Organische Chemie, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18A, 72076, Tübingen, Germany. Electronic address: [email protected].
  • 2 Department of Microbiology and Molecular Genetics, University of the Punjab, Quaid-e-Azam Campus, 54590, Lahore, Punjab, Pakistan.
  • 3 Department of Microbiology and Molecular Genetics, University of the Punjab, Quaid-e-Azam Campus, 54590, Lahore, Punjab, Pakistan; Department of Microbiology and Molecular Genetics, The Women University, Multan, Punjab, Pakistan.
  • 4 Mikrobiologie/Biotechnologie, Interfakultäres Institut für Mikrobiologie und Infektionsmedizin, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 28, 72076, Tübingen, Germany.
  • 5 Institut fur Organische Chemie, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18A, 72076, Tübingen, Germany.
PMID: 26946375 DOI: 10.1016/j.micres.2016.01.003
Abstract

Two strains identified as Nocardia caishijiensis (SORS 64b) and Pseudonocardia carboxydivorans (AGLS 2) were isolated as endophytes from Sonchus oleraceus and Ageratum conyzoides respectively. The analysis of their extracts revealed them to be strongly bioactive. The N. caishijiensis extract gave an LC50 of 570 μg/ml(-1) in the brine shrimp cytotoxicity assay and an EC50 of 0.552 μg/ml(-1) in the DPPH antioxidant assay. Antimicrobial activity was observed against Methicillin resistant Staphlococcus aureus (MRSA) and Escherichia coli ATCC 25922 (14 mm), Klebsiella pneumoniae ATCC 706003 (13 mm), S. aureus ATCC 25923 (11 mm) and Candida tropicalis (20 mm). For the extract of P. carboxydivorans the EC50 was 0.670 μg/ml(-1) and it was observed to be more bioactive against Bacillus subtilis DSM 10 ATCC 6051 (21 mm), C. tropicalis (20 mm), S. aureus ATCC 25923 (17 mm), MRSA (17 mm), E. coli K12 (W1130) (16 mm) and Chlorella vulgaris (10 mm). The genotoxicity testing revealed a 20 mm zone of inhibition against the polA mutant strain E. coli K-12 AB 3027 suggesting damage to the DNA and polA genes. The TLC and bioautography screening revealed a diversity of active bands of medium polar and nonpolar compounds. Metabolite analysis by HPLC-DAD via UV/vis spectral screening suggested the possibility of stenothricin and bagremycin A in the mycelium extract of N. caishijiensis respectively. In the broth and mycelium extract of P. carboxydivorans borrelidin was suggested along with α-pyrone. The HPLC-MS revealed bioactive long chained amide derivatives such as 7-Octadecenamide, 9, 12 octadecandienamide. This study reports the rare actinomycetes N. caishijiensis and P. carboxydivorans as endophytes and evaluates their bioactive metabolites.

Keywords

Actinomycetes; Ageratum; Endophytes; Nocardia; Pseudonocardia; Sonchus.

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