2. Academic Validation
  3. Oligomycins A and E, major bioactive secondary metabolites produced by Streptomyces sp. strain HG29 isolated from a Saharan soil

Oligomycins A and E, major bioactive secondary metabolites produced by Streptomyces sp. strain HG29 isolated from a Saharan soil

  • J Mycol Med. 2018 Mar;28(1):150-160. doi: 10.1016/j.mycmed.2017.10.007.
N Khebizi 1,  H Boudjella 2,  C Bijani 3,  N Bouras 4,  H-P Klenk 5,  F Pont 6,  F Mathieu 7,  N Sabaou 1
Affiliations

Affiliations

  • 1 Laboratoire de biologie des systèmes microbiens (LBSM), école normale supérieure de Kouba, Alger, Algeria.
  • 2 Laboratoire de biologie des systèmes microbiens (LBSM), école normale supérieure de Kouba, Alger, Algeria. Electronic address: h-boudjella@live.fr.
  • 3 Laboratoire de chimie de coordination (LCC), CNRS, université de Toulouse, UPS, INPT, LCC, 205, route de Narbonne, 31077 Toulouse, France.
  • 4 Laboratoire de biologie des systèmes microbiens (LBSM), école normale supérieure de Kouba, Alger, Algeria; Département de biologie, faculté des sciences de la nature et de la vie et sciences de la terre, université de Ghardaïa, BP 455, 47000 Ghardaïa, Algeria.
  • 5 School of biology, Newcastle university, Ridley building, NE1 7RU Newcastle upon Tyne, United Kingdom.
  • 6 Proteomics group, Inserm UMR1037, centre de recherches en cancérologie de Toulouse (CRCT), Toulouse, France.
  • 7 Laboratoire de génie chimique, CNRS, INPT, UPS, université de Toulouse, Toulouse, France.
PMID: 29158025 DOI: 10.1016/j.mycmed.2017.10.007
Abstract

An actinobacterial strain, HG29, with potent activity against pathogenic, toxigenic and phytopathogenic fungi was isolated from a Saharan soil sample of Algeria. On the basis of morphological and chemotaxonomic characteristics, the strain was classified in the genus Streptomyces. Analysis of the 16S rRNA gene sequence showed a similarity level of 99.3% with Streptomyces gancidicus NBRC 15412T. The comparison of its cultural and physiological characteristics with this species revealed significant differences. Moreover, the phylogenetic tree showed that strain HG29 forms a distinct phyletic line within the genus Streptomyces. Production of Antifungal activity was investigated by following kinetics in shake broth. The highest Antifungal activity was obtained after five days of fermentation, and in the dichloromethane extract. Two active compounds, NK1 and NK2, were purified by HPLC using a C18 column. Their chemical structures were identified through nuclear magnetic resonance experiments and mass spectrometry as oligomycins E and A, respectively, which have not been reported to be produced by S. gancidicus. The two bioactive compounds exhibited significant Antifungal activity in vitro, showing minimal inhibitory concentrations (MICs) values between 2 and 75μg/mL.

Keywords

Antifungal activity; Minimal inhibitory concentrations; Oligomycins; Streptomyces; Taxonomy.

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