Patrick Larkin, Ph.D. - US grants

A grant has been awarded to Dr. Patrick Larkin, Dr. Kirk Cammarata, Dr. Eugene Billiot, Dr. Feri Billiot, Dr. Patrick Louchouarn and Dr. Mark Morvant at Texas A&M University-Corpus Christi to
Acquire instrumentation to study the environmental factors affecting the distribution of seagrasses along the south Texas Gulf coast. The instruments to be acquired include (1) a genetic analyzer for DNA sequencing and molecular marker analysis, (2) an ultracentrifuge for the preparation of subcellular fractions, organelle DNA, proteins and peptides (3) a capillary electrophoresis system for the analysis of environmental pollutants such as herbicides, organometallic compounds and inorganic ions and (4) a freeze dryer for the preparation of sediment and plant tissues for analysis.

The goals and scope of this research will be to 1) assess the distribution, heterogeneity and flow of genes among seagrass meadows along the south Texas gulf coast; 2) advance our understanding of the significance of organic and metal pollutants in our unique environment; and 3) develop plant-based systems (or microcosms) which can specifically detoxify contaminants in soil or water. Studies will include the analysis of seagrass species (Halodule beaudetteii, Halophila engelmannii, Cymodocea filiformis, Thalassia testudinum, and Ruppia maritima) for genetic diversity and gene flow among populations highly impacted by agricultural, recreational and industrial activity. Analysis of genetic diversity will be undertaken by the development of molecular markers, direct DNA sequencing and statistical analysis. Seagrasses and associated aquatic plants will be studied to assess their ability for the bioaccumulation and/or detoxification of environmental contaminants. In particular, mechanistic studies will utilize capillary electrophoresis technology to characterize the occurrence of relevant chelators in study plants. Parameters to be identified and quantified include metal concentrations, organic acids, amino acids, phytochelatins, and transport proteins. We also wish to study how plants and seagrasses in particular, respond to/remove organic pollutants, since a number of such contaminants exist along the Texas gulf coast's unique environment. We would like to: 1) quantify hydrophobic organic carbons (HOC's) in aquatic/wetland plant tissues to determine partitioning and biological fate, and 2) compare HOCs in rhizosphere vs. non-rhizosphere sediments for various plants.

Our research proposes to answer many questions concerning habitat requirements, potential mechanisms of pollutant phytoremediation and the importance of genetics for conservation, propagation and establishment of seagrass and associated aquatic plant beds.

Acquisition of a Digital Imaging System to Support Research and Research Training in Applications of Molecular Biology

A grant has been awarded to Dr. Kirk Cammarata and colleagues at Texas A&M University-Corpus Christi (TAMU-CC) to acquire a digital imaging system for sensitive detection of multicolor fluorescence, radioactivity and chemiluminescence data generated by a variety of DNA- and protein-based research techniques. The imaging package includes blue, green and red fluorescence excitation capabilities, bandpass emission filters, 10 um-resolution optics and microarray slide holder, storage phosphor cassettes and phosphor image eraser, and data analysis software. The instrumentation will support molecular biological studies on the health of the Gulf of Mexico coastal environment. The research will explore the mechanisms by which aquatic organisms respond to environmental contaminants such as endocrine disruptors and toxic heavy metals, and how DNA- and protein-based molecular techniques can be used to monitor environmental impacts. The Gulf coast hosts a diversity of uses including fisheries, wildlife, industry and recreation. But it is also a sensitive collection point for environmental contaminants originating from approximately two-thirds of the continental United States. Knowledge of how aquatic organisms respond to pollutants, in conjunction with molecular assay methods to measure these responses, will result in a cause and effect understanding that may support risk-based environmental assessment and regulation.

The research facilitated by the imaging system will support the empowerment of regulatory agencies to make rational, fact-based decisions regarding environmental impacts of pollution. Moreover, the mission of the College of Science and Technology at TAMU-CC is, in part, to increase minority participation in the sciences. The research training and teaching needs of Hispanic-Serving Institutions (HSI) in South Texas will be enhanced because the instrumentation will enable research projects not previously possible in the region.

With this award from the Major Research Instrumentation (MRI) Program, the Department of Chemistry at Texas A&M University in Corpus Christi will acquire a gas chromatograph mass spectrometer (GC/MS). This equipment will enhance research in a number of areas including a) the semiquantitative analysis of pesticides and other suspected endocrine disruptors; b) analysis of climate patterns based on sedimentary lipid components; c) mechanistic studies on aquatic organisms' response to encironmental contaminants; and d) development of a novel air sampling technique that uses solid cyclodextrins to trap unstable volatile polycyclic aromatic hydrocarbons.

Gas chromatograph with mass spectrometric detection (GCMS) is an extremely powerful technique used for the separation and analysis of complex mixtures. This instrument will substantially strengthen scientific research in environmental chemistry at Texas A&M University-Corpus Christi, a primarily undergraduate institution.

With support from the Major Research Instrumentation (MRI) Program, the Department of Physical and Life Science at Texas A&M University in Corpus Christi will acquire an atomic absorption (AA) graphite furnace and microwave digestor. This equipment will enhance research in a number of areas including studies on a) metal-stress response mechanisms in plants; b) the distribution and fate of endocrine disrupting compounds in the environment; and c) contaminant measurements in former uranium mines.

Atomic absorption spectroscopy allows chemists to determine the concentration of metals at environmental sensitive levels. Thus these studies will have a significant impact in environmentally chemistry. The instrument will also be used in undergraduate and graduate laboratory courses.