title: Extracellular synthesis of zinc oxide nanoparticle using seaweeds of gulf of Mannar, India.
abstract: BACKGROUND
  The biosynthesis of metal nanoparticles by marine resources is thought to be clean, nontoxic, and environmentally acceptable "green procedures". Marine ecosystems are very important for the overall health of both marine and terrestrial environments. The use of natural sources like Marine biological resources essential for nanotechnology. Seaweeds constitute one of the commercially important marine living renewable resources. Seaweeds such as green Caulerpa peltata, red Hypnea Valencia and brown Sargassum myriocystum were used for synthesis of Zinc oxide nanoparticles.
  
  
  RESULTS
  The preliminary screening of physico-chemical parameters such as concentration of metals, concentration of seaweed extract, temperature, pH and reaction time revealed that one seaweed S. myriocystum were able to synthesize zinc oxide nanoparticles. It was confirmed through the, initial colour change of the reaction mixture and UV visible spectrophotometer. The extracellular biosynthesized clear zinc oxide nanoparticles size 36 nm through characterization technique such as DLS, AFM, SEM -EDX, TEM, XRD and FTIR. The biosynthesized ZnO nanoparticles are effective antibacterial agents against Gram-positive than the Gram-negative bacteria.
  
  
  CONCLUSIONS
  Based on the FTIR results, fucoidan water soluble pigments present in S. myriocystum leaf extract is responsible for reduction and stabilization of zinc oxide nanoparticles. by this approach are quite stable and no visible changes were observed even after 6 months. These soluble elements could have acted as both reduction and stabilizing agents preventing the aggregation of nanoparticles in solution, extracellular biological synthesis of zinc oxide nanoparticles of size 36 nm.
authors.affiliation: Department of Marine and Coastal Studies, Madurai Kamaraj University, Madurai, Tamil Nadu 21, India. sangeethaplasmodium@gmail.com.
authors.forename: Sangeetha
authors.initials: S
authors.lastname: Nagarajan
authors.forename: Kumaraguru
authors.initials: K
authors.lastname: Arumugam Kuppusamy
mesh_terms: D000900:Anti-Bacterial Agents / Q000096:biosynthesis* / Q000494:pharmacology; D000935:Antifungal Agents / Q000378:metabolism* / Q000494:pharmacology; D001234:Aspergillus niger / Q000187:drug effects / Q000254:growth & development; D002176:Candida albicans / Q000187:drug effects / Q000254:growth & development; D046068:Caulerpa / Q000737:chemistry / Q000378:metabolism; D006094:Gram-Positive Bacteria / Q000187:drug effects / Q000254:growth & development; D055772:Green Chemistry Technology; D006863:Hydrogen-Ion Concentration; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles / Q000737:chemistry*; D010084:Oxidation-Reduction; D011134:Polysaccharides / Q000737:chemistry / Q000378:metabolism; D000461:Rhodophyta / Q000737:chemistry / Q000378:metabolism; D044647:Sargassum / Q000737:chemistry / Q000378:metabolism; D012624:Seaweed / Q000737:chemistry / Q000378:metabolism*; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D011134:Polysaccharides; C007789:fucoidan; D015034:Zinc Oxide