Dr. Weiner' Photograph
Ronald M. Weiner

Ph.D. - Iowa State University, 1970.
Professor
Department of Cell Biology and Molecular Genetics
University of Maryland
College Park, MD 20742
Microbiology, Campus 4451
Telephone: (301)-405-1605
FAX: (301)-405-5446
E-mail: rw19@umail.umd.edu
Research Interests:Microbial Ecology; Bioremediation; Molecular Mechanisms of Microbial Adhesion and Biofouling.

The researchers in my laboratory are learning how procaryotes adhere to, and colonize, marine surfaces. We are focusing on capsular exopolysaccharide (EPS) which may be a primary adhesion and which is a dominant component of marine biofilms. We most commonly study the model organism, Hyphomonas which has species isolated from deep sea hydrothermal vents. It has a biphasic life cycle with a pelagic and adherent stage. It tolerates a strikingly wide range of environmental conditions and has both autotrophic and heterotrophic capability. We are examining the molecular mechanisms and developmental cell biology that confer a potent survival advantage upon this organism.

Other investigations include the way that periphytic bacteria signal invertebrates to colonize surfaces. We have shown that some Shewanella and Hyphomonas species synthesize enzymes involved in tyrosine degradation and oxidation and that a primary product, L-dihydroxyphenyl alanine (L-Dopa), can cue invertebrate set. We have cloned the parahydroxy-phenyl-pyruvate oxidase (PHPPO) operon and isolated its product, homogentisic acid. The function and expression of PHPPO among diverse marine species has been determined.

We are also studying degradative exoenzymes, synthesized by marine bacteria, that foster heterotrophic growth in marine biofilms. Three of these are chitinase, agarases and proteases. We are learning about their expression mode of action and role in inanamate surface or algal colonization.

We apply these theoretical findings as appropriate and over a dozen patents have been issued as a result of this work.

Selected Publications:

Weiner, R., S. Langille, E. Geesey, E. Quintero. 1997. Adhesive extracellular polymers of Hyphomonas in advances in marine technology. N. Saxena Ed. Univ. Press.

Walch, M., M.E. Ewell, E. Chang, and R. Weiner. 1997. Concentration of metal pollutants in bacterial biofilms and inhibition of oyster settlement and metamorphosis (Reviewed Monograph) Md. DNR Pub. 39p.

Zerfas, P., M. Kessel, E. Quintero and R. Weiner. 1997. Fine structure evidence for cell membrane partitioning of the nucleoid and cytoplasm during bud formation in Hyphomonas. J. Bacteriol. 179:148-156.

Baty, A., Frolund, B., G. Geesey, S. Langille, E. Quintero, P. Suci and R. Weiner. 1996. Adhesion of biofilms to inert surfaces: a molecular level approach directed at the marine environment. Biofouling 10:111-121.

Chang, Y, S. Coon, M. Walch, and R. Weiner. 1996. Effects of Hyphomonas biofilms on the toxicity of copper and zinc to Crassostrea gigas and C. virginica larval set. J. Shellfish Res. 15:589-595.

Elyem, C., E. Quintero, and R. Weiner. 1996. Upstream sequence of the arahydroxyphenylpyruvate dioxygenase (melA) coding region leading to enhanced expression in Shewanella colwelliana. Microbios 86:163-174.

Frolund, B., Suci, P., S. Langille, R. Weiner and G. Geesey. 1996. Influence of protein conditioning films on binding of a bacterial polysaccharide adhesion from Hypomonas MHS-3. Biofouling 10:17-30.

Beveridge, T., M. Powell, L. Graham and R. Weiner. 1996. The Postdoctoral Dilemma. Amer. Soc. For Microbiol. News 62:189-193.

Quintero, E. and R. Weiner. 1995. Evidence for the adhesive function of the exopolysaccharide of Hyphomonas MHS-3 in its attachment to surfaces. Appl. and Environ. Microbiol. 61:1897-1903.

Weiner, R., S. Langille and E. Quintero. 1995. Structure, function and immunochemistry of bacterial capsular exopolysaccharides. J. Ind. Microbiol. 15:339-346

Quintero, E. and R. Weiner. 1995. Physical and chemical characterization of the polysaccharide capsule of the marine bacterium, Hyphomonas strain MHS-3. J. Ind. Microbiol. 15:347-351

Kotob, S., S. Coon, E. Quintero and R. Weiner. 1995. Homogentisic acid is the primary precursor of melanin synthesis in Vibrio cholerae Hyphomonas sp. and Shewanellacolwelliana. Appl. Env. Microbiol. 61, 1620-1622.

Coon, S., S. Kotob, B. Jarvis, S. Wang, W. Fuqua and R. Weiner. 1994. Homogentisic acid is the product of MelA which mediates melanogenesis in the marine bacterium Shewanella colwelliana D. Appl. Environ. Microbiol. 60:3006-3010.

Abu, G., R. Weiner and R. Colwell. 1994. Glucose metabolism and polysaccharide accumulation in the marine bacterium Shewanella colwelliana. World J. Microbiol. Biotechnol. 10:543-546.

Weiner, R., D. Sledjeski, E. Quintero, S. Coon and M. Walch. 1993. Periphytic bacteria cue oyster larvae to set on fertile benthic biofilms. p. 217-220. In Proc. 6th Int. Symp. on Microbiol. Ecol. R. Guerrero & C. Pedros Alio, Eds. Sp. Soc. for Microbiol., Barcelona.

Sledjeski, D. and R. Weiner. 1993. Production and characterization of monoclonal antibodies specific for Shewanella colwelliana exopolysacchrides. Appl. Environ. Microbiol. 59:1565-1572.

Fuqua, C. and R. Weiner. 1993. The mel A gene is essential for melanin biosynthesis in Shewanella colwelliana. J. Gen. Microbiol. 139:1105-1114.

Weiner, R.M., C. Fuqua, S. Coon, D. Sledjeski and R.R. Colwell. 1992. Tyrosinases, biofilms and oyster set. 542-548 In: Developments in Marine Biotechnology. C. Nash, Ed. W.C. Brown.

Weiner, R., E. Quintero and D. Sledjeski. 1992. Regulation of synthesis of novel complex marine polysaccharides. pp 459-470. In: Developments in Marine Biotechnology. C. Nash, Ed. W.C. Brown.

Weiner, R., D. Sledjeski, E. Quintero, S. Coon and M. Walch. 1992. Periphytic bacteria cue oyster larvae to set on fertile benthic biofilms. Trends in Microbial Ecol. 8: 217-220.

Tritar, S., D. Prieur and R. Weiner. 1992. Effects of bacterial films on the settlement of the oysters Crassostrea gigas and Ostrea edulis and the scallop, Pecten maximus. J. Shellfish Res. 11:325-330.

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