title: Production of Non-Ribosomal Peptide Synthetase (NRPS)-Dependent Siderophore by Aeromonas Isolates.
abstract: BACKGROUND
  Aeromonas species are Gram-negative ubiquitous bacteria, facultative anaerobic rods that infect both invertebrates and vertebrates. Various fish species develop hemorrhagic disease and furunculosis due to Aeromonas spp. Aeromonas strains generate certain active compounds such as siderophores, which are the final products of non-ribosomal peptide synthetase (NRPS) activity. The present study attempted to investigate the prevalence of Aeromonas isolates in marketed fish sources. We also examined the siderophore production ability of these isolates.
  
  
  METHODS
  Among the molecular tools, 16S rRNA analysis was used to identify Aeromonas species and their epidemiological distributions. The hemolytic activity of the strains and biochemical assays were used to confirm the identity of the isolates. We also determined the chemical nature of siderophores in these strains.
  
  
  RESULTS
  A total of seven Aeromonas isolates obtained from fish were included to determine the siderophore production. Of 7 isolates, 4 produced siderophore, and their chemical nature was also determined. The siderophore produced by Aeromonas was invariably found to be of hydroxamate. Four Aeromonas isolates were selected for PCR identification of NRPS-encoding gene. The conserved sequence was present in all four selected isolates. Furthermore, siderophores were qualitatively tested for their antibacterial activity against pathogenic bacteria and a significant level of inhibitory activity was observed in siderophores from the four isolates.
  
  
  CONCLUSIONS
  Our results showed the ability of the isolated strains in production of siderophores with a high level of activity against Salmonella paratyphi. These siderophores could find applications in biomedical industries.
authors.affiliation: Department of Biotechnology, Kongunadu Arts and Science College, Coimbatore-641029, Tamilnadu, India.
authors.forename: Ramasamy
authors.initials: R
authors.lastname: Amsaveni
authors.affiliation: Department of Biotechnology, Kongunadu Arts and Science College, Coimbatore-641029, Tamilnadu, India.
authors.forename: Muthusamy
authors.initials: M
authors.lastname: Sureshkumar
authors.affiliation: K.S.R. College of Arts and Science, Tiruchengode-637215, Tamilnadu, India.
authors.forename: Arthanari
authors.initials: A
authors.lastname: Aravinth
authors.affiliation: Department of Biotechnology, Kongunadu Arts and Science College, Coimbatore-641029, Tamilnadu, India.
authors.forename: Joseph
authors.initials: J
authors.lastname: Reshma Mary
authors.affiliation: 3Farmer's Bio-Fertilizers and Organics, 461, Sri Ragavendra Gardens, G.N. Mills Post, Coimbatore-641029, Tamilnadu, India.
authors.forename: Govindasami
authors.initials: G
authors.lastname: Vivekanandhan
mesh_terms: D000333:Aeromonas / Q000145:classification / Q000302:isolation & purification / Q000378:metabolism*; D000818:Animals; D005399:Fishes / Q000382:microbiology*; D006877:Hydroxamic Acids / Q000378:metabolism*; D010453:Peptide Synthases / Q000235:genetics / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012482:Salmonella paratyphi A / Q000187:drug effects; D017262:Siderophores / Q000096:biosynthesis* / Q000494:pharmacology
chemical_list: D006877:Hydroxamic Acids; D012336:RNA, Ribosomal, 16S; D017262:Siderophores; D010453:Peptide Synthases; C104385:non-ribosomal peptide synthase
keywords: Aeromonas; Hydroxamate; Siderophores