title: Optimization of antifungal production by an alkaliphilic and halotolerant actinomycete, Streptomyces sp. SY-BS5, using response surface methodology.
abstract: OBJECTIVE
  Optimization of medium components and physicochemical parameters for antifungal production by an alkaliphilic and salt-tolerant actinomycete designated Streptomyces sp. SY-BS5; isolated from an arid region in south of Algeria.
  
  
  METHODS
  The strain showed broad-spectrum activity against pathogenic and toxinogenic fungi. Identification of the actinomycete strain was realized on the basis of 16S rRNA gene sequencing. Antifungal production was optimized following one-factor-at-a-time (OFAT) and response surface methodology (RSM) approaches. The most suitable medium for growth and antifungal production was found using one-factor-at-a-time methodology. The individual and interaction effects of three nutritional variables, carbon source (glucose), nitrogen source (yeast extract) and sodium chloride (NaCl) were optimized by Box-Behnken design. Finally, culture conditions for the antifungal production, pH and temperature were studied and determined.
  
  
  RESULTS
  Analysis of the 16S rRNA gene sequence (1454 nucleotides) assigned this strain to Streptomyces genus with 99% similarity with Streptomyces cyaneofuscatus JCM4364(T), the most closely related. The results of the optimization study show that concentrations 3.476g/L of glucose, 3.876g/L of yeast extract and 41.140g/L of NaCl are responsible for the enhancement of antifungal production by Streptomyces sp. SY-BS5. The preferable culture conditions for antifungal production were pH 10, temperature 30°C for 09 days.
  
  
  CONCLUSIONS
  This study proved that RSM is usual and powerful tool for the optimization of antifungal production from actinomycetes.
authors.affiliation: Laboratoire de Microbiologie Appliquée, Faculté des Sciences de la Nature et de la Vie, Université Abderrahmane MIRA de Bejaia, Targa Ouzemmour, 06000 Bejaia, Algeria.
authors.forename: Y
authors.initials: Y
authors.lastname: Souagui
authors.affiliation: Laboratoire de Chimie et Biochimie des Microorganismes, Université de Strasbourg/CNRS-UMR 7177, Institut Le Bel, 4, rue Blaise-Pascal, 67081 Strasbourg, France.
authors.forename: D
authors.initials: D
authors.lastname: Tritsch
authors.affiliation: Laboratoire de Chimie et Biochimie des Microorganismes, Université de Strasbourg/CNRS-UMR 7177, Institut Le Bel, 4, rue Blaise-Pascal, 67081 Strasbourg, France.
authors.forename: C
authors.initials: C
authors.lastname: Grosdemange-Billiard
authors.affiliation: Laboratoire de Microbiologie Appliquée, Faculté des Sciences de la Nature et de la Vie, Université Abderrahmane MIRA de Bejaia, Targa Ouzemmour, 06000 Bejaia, Algeria. Electronic address: mouloudkecha@yahoo.fr.
authors.forename: M
authors.initials: M
authors.lastname: Kecha
mesh_terms: D039903:Actinobacteria / Q000145:classification / Q000378:metabolism; D000935:Antifungal Agents / Q000378:metabolism*; D019149:Bioreactors / Q000592:standards; D002138:Calibration; D003470:Culture Media / Q000737:chemistry / Q000494:pharmacology; D006216:Halobacteriaceae / Q000145:classification / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008828:Microbiological Techniques / Q000592:standards*; D055049:Salt Tolerance; D013302:Streptomyces / Q000145:classification / Q000378:metabolism*; D013696:Temperature
chemical_list: D000935:Antifungal Agents; D003470:Culture Media
keywords: Actinomycète alcalophile; Alkaliphilic actinomycete; Antifungal production; Aspergillus; Méthodologie des surfaces de réponses; Optimisation; Optimization; Production d’antifongiques; Response surface methodology