National Dendrimer and Nanotechnology Center  The National Dendrimer and Nanotechnology Center is the catalyst for dendrimer-based research initiatives. The Center’s current research agenda focuses on several types of dendrimer and nanoscale sciences: Drug encapsulation, release and disease targeting protocols are being established and tested for cancer therapy and anti-flammatory drug systems using a range of dendrimer carrier structures; researching cytotoxicity of dendrimers and other nanoscale structures; the use of dendrimers as a catalyst in the production of carbon nanotubes at the lowest temperatures recorded; the attachment of oligonucleotides to dendrimers for targeting, amplification or detection in biological systems; development of nuclear magnetic reagents which allow higher resolution and site specific targeting to disease or inflammation; stabilization of nano-crystals or quantum dots with unique optical, electronic or other properties for use in bio-labeling, and flat panel display technologies; development of lower-cost synthetic routes to new proprietary dendrimers and dendritic polymers; development of dendrimers as in-vivo nano-diagnostic agents and devices. |
Development of Green Organic Catalysts This research program is focused on development of green organic catalysts based on an architecture of buckminsterfullerene (C60) molecules surrounding either a polymer resin bead or dendrimer. These catalysts are activated by light and can function in either organic or aqueous media. We hope to further develop the catalysts to the point where we can carry out stereoselective oxidations and/or decontaminate water. |
chemistry of free radical Species Produced by the Irradiation of Biomolecules  Of principal interest are the mechanisms for radiation damage to DNA. The principal biological effect of radiation on a cell is caused by the direct interaction of radiation with DNA or molecules immediately surrounding the DNA which transmit the radiation damage to the DNA. Professor Sevilla's lab has established that the initial effect of radiation is to produce ion radicals on the DNA bases and recently has found DNA radicals on the sugar phosphate backbone. These species directly lead to strand breaks and biologically relevant damage.
Recent efforts have looked into the production of sugar radicals in DNA by high energy irradiation. These species are of critical importance to the subsequent biological damage and as a consequence quantitation of the numbers of sugar radicals and their identity gives important mechanistic information. Work in this lab has found that about 10% of all radicals produced are on the sugar phosphate backbone for gamma rays but as much as 30% of radicals are on the sugar phosphate backbone for ion beam irradiated DNA. This lead to the hypothesis that excited states of the DNA base cation radicals may lead to damage to the sugar portion of DNA. A series of recent papers from this lab has shown this is indeed the case. These efforts have identified the C1’, C3’ and C5’ sites on the sugar as those that are most prone to damage by this mechanism. |
Examining Biomass Substrates in Ethanol Production as Source of Alternative Fuel Bio-fuel ethanol as an alternative fuel is gaining interests for environmental and economical reasons. To reach ethanol goals needed in the United States, it will be essential to take advantage of various biomass substrates for ethanol production (e.g. agricultural and industrial waste products). Recent work includes study of the growth inhibitor, furfural, which induces cellular stress signals in Saccharomyces cerevisiae. Using various fluorescent indicators and transmission electron microscopy techniques, it was determined that furfural causes an increase in reactive oxygen species accumulation, cellular membrane damage (vacuole and mitochondrial membranes), chromatin damage, and cytoskeletal damage in wild-type S. cerevisiae. Whether or not overexpressing any of the previously identified genes will reduce oxidative damage is being investigated. |
Elucidating and Manipulating the Role of Malate in the Maintenance of Stomatal Aperture  The purpose of this research project is to use genetic engineering to alter plant responses to growth under irrigation. Irrigation is widely used to prevent crop losses due to drought. In the United States, approximately 70% of the water diverted by humans is used to irrigate crops. Irrigation has dried up rivers and caused salinization of crop land, which reduces crop productivity. Genetically modified crops that use less water under irrigation conditions have the potential to save massive amounts of irrigation water and to reduce the destruction of farm land.
The majority of water used by plants is lost to the atmosphere through openings called stomata on leaf surfaces. Specialized guard cells that border the stomata control stomatal opening and closing through changes in the concentrations of certain ions in the guard cells. Prof. Laporte's research focuses on one of these ions, malate, which is maintained at high concentrations in guard cells when stomata are open. The metabolism of malate is linked to stomatal closure. Prof. Laporte will study the enzyme that metabolizes malate to look for ways of altering its activity, thereby modulating the size of the stomatal opening while maintaining the stomatal function critical to optimal plant growth.
The long-term goals of this project include not only a better understanding of the way in which malate metabolism in guard cells regulates the size of the stomatal opening, but also the actual molecular engineering of plants with conservative water use under irrigation. In order to accomplish this, Prof. Laporte will conduct genetic studies of the gene for the malate-metabolizing enzyme, identifying which form of the enzyme is made in guard cells. She will then evaluate the size of the stomatal opening and the use of water in plants that make more the metabolizing enzyme in guard cells than usual, plants that make no metabolizing enzyme in guard cells, and plants that make a mutant metabolizing enzyme in guard cells. These experiments will provide the information Prof. Laporte will use to engineer a plant that uses less irrigation water.
Through this research project, Prof. Laporte will also contribute to the training of undergraduate students. Eastern Michigan University has a diverse student body of high-quality undergraduates who are interested in one-on-one training with faculty members. Although many EMU students go on to graduate or professional school or join the scientific workforce; an even larger number become K-12 teachers. While pursuing the goals of this research, Prof. Laporte will train promising undergraduate students, including members of underrepresented minorities, who will become the next generation of scientists and teachers. The extensive connections between EMU and the local K-12 teaching community provide opportunities for high school students, as well as current and future teachers, to learn from and become involved in Prof. Laporte's research program. Many of the molecular, biochemical, and physiological techniques used in this project, along with the accompanying critical thinking skills, can be adapted for use in high school classrooms. |
Rhizosphere Influence on Hydrocarbon Metabolizing Microorganisms The goal of this project is to use cultivation and non-cultivation based methods to characterize the microbial populations associated with plant rhizospheres in hydrocarbon-impacted soils. A series of plots have been established in polynuclear aromatic hydrocarbon (PAH) impacted soils that have been planted with species native to Michigan. Preliminary results with these plots indicate that individual plant species have different effects on the extent of hydrocarbon removal. In this research project, experiments will be conducted to evaluate the different influences that unique plant species have on the microbial communities inhabiting the rhizospheres. This will be performed by analyzing soil samples collected from different plots at various time intervals. Microbial communities will be characterized by 1) sequencing a gene that will enable the identification of microorganisms present (16S rRNA genes) 2) sequencing genes involved in PAH-degradation (PAH dioxygenases), and 3) comparing carbon utilization profiles of rhizosphere samples. It is anticipated that these experiments will reveal microbiological factors that enable some plants to accelerate the removal of PAHs from contaminated soils, whereas others hinder their removal. The broader impacts include developing an ecological framework for understanding how an applied technology like phytoremediation can be optimized. Some aspects of this project will also be integrated into a semester long cooperative laboratory experience for a microbial ecology and plant physiology class taught during the same semester. Further, this support will be used to increase research opportunities for underrepresented populations through local outreach and through additional, formal NSF channels (e.g. REU and RET supplements). |
Biogeochemical Exploration of Acidic and Neutral Hypersaline Environments of Australia This is a collaborative project of Drs. Melanie R. Mormile, Francisca E. Oboh-Ikuenobe (University of Missouri-Rolla), and Kathleen C. Benison (Central Michigan University) to determine if evaporites truly trap a representative population of microorganisms from hypersaline environments. If this is found to be true, these findings can possibly be extrapolated to microorganisms entrapped in ancient or possibly extraterrestrial evaporites and used to describe previous microbial communities and therefore, make interpretations about past water chemistries and past climates. Microorganisms represent the basic life forms existing in most environmental settings. They are sensitive to climatic parameters, and can influence water chemistry, biological activity, and mineralization. Evaporite minerals are a wealth of paleoenvironmental data due to their sensitivity to climate, water chemistry, and hydrology. In addition, evaporites can form in extreme environmental conditions, such as extremely acid saline lakes in Western Australia. These lakes might serve as good analogs to Mars. Traditionally, studies of evaporite settings and their deposits have overlooked microorganisms largely because they are generally poorly preserved in the rock record. However, through this research, answers to the following questions will be found: What microorganisms are present in the lake waters, groundwaters, and sediments of acid and neutral saline lake environments? Are the microorganisms found living in the waters represented in the fluid inclusions of the evaporite minerals? Are the microorganisms specific acidophiles? What role did the microorganisms play in the evolution of the water chemistry? To answer these questions, a sampling trip will be made to Australia to collect a comprehensive set of lake water, groundwater, evaporite, and siliciclastic sediment samples. The following objectives will be achieved: 1. Identify and compare the biological remains in halite and gypsum with those in their parent waters and sediments. Both traditional culture methods and molecular biology techniques will be used to compare the microbial populations in the environments listed above. 2. Grow evaporite crystals under laboratory conditions to study selected environmental influences on crystal formation and the microorganisms that become entrapped. 3. Identify any differences in microorganisms (ranging from prokaryotes to freshwater dinoflagellates and algae) between neutral and moderately acidic saline lakes and groundwaters in Victoria and Western Australia, between neutral and extremely acidic saline lakes within a small region of Western Australia, as well as among extremely acidic saline lakes and groundwaters in Western Australia. The 16S rDNA from the bacteria isolated from these environments will be sequenced and compared. 4. Constrain depositional, environmental, and climatic conditions using basic sedimentology, petrography, fluid inclusion studies, and palynology. Sedimentary structures and grain characteristics will be used to trace depositional history.
We anticipate that novel microorganisms will be found. These organisms can possibly be used for the bioremediation of contaminated sites that are impacted by extremes in saline and acidic conditions. In addition, our findings will have implications for future Mars research and the possibility that life can occur on planetary bodies besides Earth. Of all the planetary bodies explored, Mars most closely resemble Earth. In particular, terrestrial acid sedimentary systems are similar in general mineralogy, geochemistry, and geomorphology to the Martian surface. Furthermore, this project will be responsible for the training of students ranging from undergraduate level to Post-Doctoral students. There is also a significant outreach component that includes a partnership with the St. Louis Science Center as well as a course on the geology and microbiology of extreme environments targeted towards K-12 educators. |
Using Maize as a Model System to Study a Novel Family of Helitron Related Transposable Elements Transposable elements have played an integral role in evolution and they constitute the most abundant entities in the eukaryotic genome. Helitrons are a recently-discovered family of transposable elements that apparently transpose through replication and strand replacement. Despite their abundance, there is no direct genetic evidence or proof for the existence of an autonomous Helitron. The investigators recently described two maize mutants that were caused by Helitron insertion and provided the first evidence that an active Helitron may reside in the present-day maize genome. This Small Grant for Exploratory Research will establish the direct genetic evidence of an active Helitron. This is high-risk project because the assertion that these maize mutants are caused by relatively recent insertion of Helitrons is based on the assumption that these were isolated in the 1900s. However, there remains a remote possibility that these mutants may represent remnants of ancient alleles that were not discovered earlier. The approach is potentially high pay-off because understanding the mode of transposition of this novel family of transposable elements may yield tools for crop improvement and provide novel insights into genome structure and organization. The objective of the project is to genetically identify the autonomous Helitron by monitoring various maize lines for somatic and heritable reversion events. This is essential in order to definitely identify an autonomous element and establish maize as a system to study the transposition of Helitrons. Broader Impact: The proposed research will provide interdisciplinary training opportunities for both undergraduate and graduate students in Genetics, Molecular Biology and Bioinformatics and reach out to high school students involved in the field experiments. A new course has been developed specifically to integrate Bioinformatics into the mainstream undergraduate and graduate curricula at Oakland University. The students will gain hands-on experience in gene discovery and annotation of sequence data generated by the proposed research. |
Biochemical Characterization of Carbofuran Hydroxylase This project supports collaborative research between Dr. Rasul Chaudhry, Department of Biological Sciences, Oakland University, Oakland, Michigan and Dr. Narayan Roy, Department of Biochemistry and Molecular Biology, University of Rajshahi, Bangladesh. They plan to study certain enzymes that degrade pesticides. The PIs have studied microbial degradation of carbamates and isolated microorganisms that can degrade these chemicals. Microorganisms either hydrolyze or oxidize the chemicals. Hydrolytic processes are less efficient and partially degrade pesticides, whereas oxidation reactions involved in degradation of carbamates are efficient, but more complex. The goal of the study is to determine the molecular mechanism of microbial oxidation of carbofuran. Using a variety of biochemical and molecular biology techniques, the PIs will test the following hypotheses: 1. A mixed function oxygenase, carbofuran hydroxylase, catalyzes the reaction of carbofuran to 4-hydroxycarbofuran. 2. A cytochrome P-450 or another unknown cofactor is involved in the electron transport circuit from NADPH to molecular oxygen. The following four specific aims will be pursued: 1. Purify the enzyme complex responsible for hydroxylation of carbofuran, 2. Characterize the purified enzyme, 3. Determine the components of the hydroxylase and their interactions responsible for catalyzing the reaction, and 4. Investigate the diversity of pesticide-degrading microorganisms. A combined expertise of the collaborating investigators, a biochemist and a molecular biologist will help solve the novel mechanism of induction and functioning of the hydroxylase complex that is key to the effective inactivation of carbofuran in the environment.
Pesticides such as carbofuran are the major group of chemicals that are used in large amounts for improving productivity and quality of crops. While these chemicals are vital to agriculture, human exposure to these pesticides through consumption of foods or drinking water has been suggested to play a key role in the early onset of neurological diseases, old age diseases such as Alzheimer's disease, immunological and reproductive disorders as well as an increase in the risk of non-Hodgkin lymphoma. This study will substantiate and extend our understanding of microbial metabolic diversity. It will also help develop new strategies for their safe and effective use as well as disposal. |
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