title: Taxonomic study of a salt tolerant Streptomyces sp. strain C-2012 and the effect of salt and ectoine on lon expression level.
abstract: Streptomyces strain C-2012 is a salt tolerant biocontrol PGPR that has been isolated from Iranian soil. The main aim of current study was finding strain C-2012 taxonomic position and to find the genes which are potentially involved in salt tolerance phenotype. Strain C-2012 chemotaxonomic, morphological and molecular characteristics indicate that this strain is a member of the genus Streptomyces. Phylogenetic analyses based on an almost complete 16S rRNA gene sequence revealed that this strain is closely related to Streptomyces rimosus JCM 4667(T). Also, DNA-DNA hybridization test estimated 74% relatedness between two strains and confirmed that C-2012 is a strain of S. rimosus. In order to find novel genes that are differentially expressed in response to the salt treatment, cDNA-AFLP was carried out. One of the selected expressed sequence tags (TDF-1) was found to be homologous to lon gene which produces a bacterial ATP-dependent proteases (proteases LA). Lon gene expression was induced following 450 mM salt (NaCl) treatment and its expression level was further (5.2-fold) increased in response to salt when ectoine was added to the medium. These results suggest that two protein protection systems including ectoine and ATP-dependent proteases synergistically are related. NaCl stress also caused an enhancement in the activity of extracellular protease.
authors.affiliation: Genetics Department, Faculty of Biological Science, Tarbiat Modares University, Tehran, Iran.
authors.forename: Akram
authors.initials: A
authors.lastname: Sadeghi
authors.affiliation: Genetics Department, Faculty of Biological Science, Tarbiat Modares University, Tehran, Iran. Electronic address: soltanib@modares.ac.ir.
authors.forename: Bahram M
authors.initials: BM
authors.lastname: Soltani
authors.affiliation: Microbial Biotechnology and Biosafety Department, Agricultural Biotechnology Research Institute of Iran (ABRII), Karaj, Iran.
authors.forename: Gholamreza Salehi
authors.initials: GS
authors.lastname: Jouzani
authors.affiliation: Microbial Biotechnology and Biosafety Department, Agricultural Biotechnology Research Institute of Iran (ABRII), Karaj, Iran.
authors.forename: Ebrahim
authors.initials: E
authors.lastname: Karimi
authors.affiliation: Microbial Biotechnology and Biosafety Department, Agricultural Biotechnology Research Institute of Iran (ABRII), Karaj, Iran.
authors.forename: Mojtaba Khayam
authors.initials: MK
authors.lastname: Nekouei
authors.affiliation: Genetics Department, Faculty of Biological Science, Tarbiat Modares University, Tehran, Iran.
authors.forename: Majid
authors.initials: M
authors.lastname: Sadeghizadeh
mesh_terms: D000599:Amino Acids, Diamino / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D010641:Phenotype; D010802:Phylogeny; D049070:Protease La / Q000235:genetics* / Q000378:metabolism; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012965:Sodium Chloride / Q000378:metabolism*; D012988:Soil Microbiology; D013302:Streptomyces / Q000145:classification* / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism
chemical_list: D000599:Amino Acids, Diamino; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D012965:Sodium Chloride; C045628:ectoine; D049070:Protease La
keywords: ATP-dependent proteases; Lon gene; PGPR; Salt tolerance; Streptomyces; cDNA-AFLP