Accession Number : ADA332718

Title :   Diatom Attachment at Aquatic Interfaces: Molecular Interactions, Mechanisms, and Physiology of Adhesion

Descriptive Note : Final rept. 1 Dec 94-30 Nov 96

Corporate Author : MICHIGAN TECHNOLOGICAL UNIV HOUGHTON

Personal Author(s) : Gretz, Michael R. ; Hoagland, Kyle D.

PDF Url : ADA332718

Report Date : 26 NOV 1997

Pagination or Media Count : 5

Abstract : We have answered fundamental questions regarding the mechanisms of attachment and the nature of the biocomposite adhesives utilized by the marine biofouling diatom Achnanthes longipes and the freshwater Cymbella cistula. During the course of this grant we have: (1) delineated the sequence of events involved in attachment of the organisms to a variety of surfaces; (2) discovered that initial adhesion is mediated by different methods/polymers on hydrophilic surfaces vs. those more hydrophobic and that bacterial 'preconditioning' has variable effects on adhesion; (3) developed methodology for mass culture of fouling diatoms and isolation of adhesive components; (4) characterized the 'proteoglycan' bioadhesives using monosaccharide and methylation analysis, NMR and other analytical techniques; (5) localized specific carbohydrate moieties of the adhesive with lectins and produced monoclonal antibodies against the adhesives and applied them as probes of structure/function of the adhesives; (6) determined that adhesion is disrupted at several levels by dichlorobenzonitrile (DCB) and related specific inhibitors of plant extracellular polysaccharide synthesis; (7) ascertained that DCB and other potential anti-fouling chemicals act intracellularly on an 18 KD membrane associated protein and that DCB doped polyimide surfaces do not inhibit adhesion; (8) discovered that adhesive structures are not assembled in the presence of high concentrations of iodide and that bromide is a limiting requirement for adhesion; and (9) created an expression library to screen for a 50 kD polypeptide from the adhesive and a peroxidase involved in crosslinking the adhesive.

Descriptors :   *ADHESION, *FOULING, *PHYSIOLOGY, *ATTACHMENT, *MOLECULE MOLECULE INTERACTIONS, *ALGAE, INTERFACES, WATER, BACTERIA, POLYMERS, COMPOSITE MATERIALS, PROTEINS, ISOLATION, SURFACES, FRESH WATER, INHIBITORS, MONOCLONAL ANTIBODIES, CARBOHYDRATES, CULTURE, ADHESIVES, CONCENTRATION(CHEMISTRY), HYDROPHOBIC PROPERTIES, PEROXIDASES, METHYLATION, IODIDES, MONOSACCHARIDES.

Subject Categories : Biochemistry
      Biology
      Inorganic Chemistry
      Organic Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE