Spotlight 2002 Abstracts
ChemistryFATTY ACID ANALYSIS IN FALL LEAVES AROUND GREEN LAKE, NY
Yaron Aronowicz and Mark Teece, Faculty of Chemistry, Box 504, 1000 Irving Avenue Syracuse, NY 13210.
The leaves shed by trees in the fall are packed with complex organic molecules that reveal information about the environment that they are from. By analyzing and identifying the fatty acids in trees found around Green Lake, NY, this study will seek to provide a benchmark for the analysis of sediments from the bottom of the lake. These fatty acids will be compared to sediments dating back to 1000 years ago; indicating the changes in tree populations and leaf composition around the lake over the years. This information will be used to better understand the effects of natural climatic changes in the region as well as the impact of human activity, such as deforestation and the construction of the Erie Canal.
Armando Avallone, Karen Galvan, Rebecca Lonergan, Julie Heinz, and John Hassett, Faculty of Chemistry, 431 Jahn Lab, SUNY College of Environmental Science and Forestry, Syracuse, NY 13210.
With the popularity of jet skis and recreational motor boat activities rising each year, more communities throughout the country have become more concerned with the potential environmental impact of gasoline combustion products. Oddly enough, there has been little in the way of studies to determine the levels of pollutants, their duration in the environment, and whether or not they pose a potential risk to the general public. In this study, a sampling unit called PISCES(Passive In-Situ Concentration Extraction Sampler) was deployed at 11 different locations in Onondaga Lake before and after the Fishing Derby which occurred in 2001. Onondaga Lake is somewhat unique in the fact that it is not a lake that is normally used recreationally by a large number of people. By taking samples before the derby occurred, we were able to obtain a general background level of gasoline contaminants before high activity and compare those to the week of the derby. Preliminary results indicate that there was a marked increase in pollutant concentrations during the week of the derby which steadily declined two weeks afterwards. When comparing the gas chromatogram of the pollutants to a gasoline standard, the results indicated that the observed pollutants were indeed gasoline components. This data indicates that with an increase of motor boat activities, the levels of gasoline will undoubtedly increase.
Wei Deng, Andrew J. Davis, David R. Katz, Lei Zhang and Dr. Theodore S. Dibble, Faculty of Chemistry, 440 Jahn Lab, SUNY College of Environmental Science and Forestry, Syracuse, NY 13210.
Alkoxy radicals are important intermediates in the atmospheric degradation of volatile organic compounds (VOC) as well as fascinating targets of basic research. The atmospheric chemistry of large alkoxy radicals is dominated by three reactions: reaction with O2, decomposition, and isomerization. Each reaction pathway has different effects on the yield and spatial distribution of ozone formed during a smog episode. Therefore, understanding the alkoxy radical chemistry in the atmosphere is of crucial importance for modeling smog chemistry. However, the present understanding of large alkoxy radicals is primarily based on indirect studies or quantum calculations. To date, direct kinetic studies have only been carried for the unimolecular decomposition of tert-butoxy radicals, and its reactions with NO and NO2 by several other research groups. Direct kinetic studies of the reactions of 2-butoxy and 3-pentoxy radicals with NO and O2 are carried out for the first time by using Laser Induced Fluorescence (LIF) method in our research to directly monitor the disappearance of large alkoxy radicals. Arrhenius expressions were obtained for all the reactions for the first time.
Jacob D. Goodrich, Kevin R. Lambrych, Ivan Gitsov. Faculty of Chemistry, 231 Jahn Laboratory, SUNY College of Environmental Science and Forestry, Syracuse, NY 13210.
Micelles composed of poly(ethylene glycol), PEG, copolymers with linear dendritic architecture are especially promising systems for targeted drug delivery, gene transfection1 and encapsulation of polycyclic aromatic hydrocarbons. Poly(ethylene glycol) is chosen as the hydrophillic bolck [A] monomer because of its proven biocompatability, its solubility in a variety of media1, and its flexible linear nature. Coupled to each end of the PEG block through ester linkages are semi-rigid, hydrophobic tri-substituted benzyl acid chloride monomers [B]. A coupling of the monomers results in a first generation linear-dendritic block copolymer of BAB configuration.
The fundamental building unit for the dendritic block is based on 3,5-dihydroxy benzoic acid (DHBA). DHBA is first protected with t-butyldimethylsilylchloride and then converted to the corresponding acid chloride for dendritic growth (see scheme). Coupling and deprotection steps can then be repeated to produce higher generation dendritic blocks. Polyester linkages in the dendritic polymers are required for effective drug delivery allowing for micellular degradation in bio-organisms. The work completed up to this point involves the synthesis only of the fundamental deprotected first generation dendrimer as a building block for multiple generation dendrimers, and ultimately micelle formation.
1. Gitsov, I.; Lambrych, K.R.; Remnant, V.A.; Pracitto, R.; J. Polymer Sci., Part A: Polym. Chem. 2000, 38, 2711
2. Frechet, J; Gitsov, I.; et. al. Chem. Mater. 1999, 11, 1267
Patrick J. Hennessy, Arthur J. Stipanovic and Francis X. Webster, Department of Chemistry, SUNY - College of Environmental Science and Forestry, 230 Jahn Laboratory, One Forestry Drive, Syracuse, NY 13210, USA. E-mail: email@example.com
Pheromones play a very important role in the world of insects. In most cases, females will emit pheromones to attract a male to mate. For many insects, the specific mating pheromone has been characterized and can now be synthesized in large quantities in the laboratory. This allows us to use these synthetic pheromones in monitoring pest population, mass trapping, and in mating disruption. The main focus of this project is to try and improve upon existing controlled release technology used for mating disruption. The current dispensers being used are relatively large, non-biodegradable, and require application by hand. In this project, micron-sized biodegradable pheromone dispensers have been fabricated and release rates studied using an “aeration” procedure as well as Thermogravimetric Analysis (TGA). The evaporation rate of the Codling and Gypsy moth sex pheromones can be modified through adsorption of these compounds onto a variety of substrates. The substrates range from cellulose derivatives to HPLC and GC column packing. To further control the evaporation rate, the substrates can be coated with biodegradable polymers, including cellulose derivatives.
Donald J. Hughes and John P. Hassett, Faculty of Chemistry, SUNY College of Environmental Science and Forestry, Syracuse, NY; and Simon Litten, Division of Water, NYS Dept. of Environmental Conservation, Albany, NY.
A popular system for measuring trace organic compounds in ambient waters uses glass-fiber filters, followed by XAD resin, a styrene-divinylbenzene copolymer. The Trace Organics Platform Sampler (TOPS), designed and fabricated by the New York State Department of Environmental Conservation, is such a system, although many similar systems exist. The filtered solids and resin-bound fractions are operationally defined as "particulate" and "soluble," respectively. We have evaluated XAD resin with respect to its ability to fully capture soluble trace organic compounds, including polycyclic aromatic hydrocarbons (PAHs), DDT, and polychlorinated biphenyls (PCBs). In field experiments using two XAD columns in series it was found that the "soluble" trace organics are incompletely captured. This data was used to estimate overall extraction efficiencies: the observed capture of individual PCB congeners by the first column ranged from nearly 100% to under 50%. It is likely that actual efficiencies are lower, due to the loss of compounds beyond the second column. The relationship of extraction efficiency with octanol-water partition coefficient was found to be complex. Efficiencies generally decreased with increasing hydrophobicity. A comparative study was conducted in which a PCB-contaminated lake was sampled on two separate occasions. Significant breakthrough occurred at a flow rate of 3.3 bed volumes per minute (BVM), while no breakthrough was found at a flow rate of 1.4 BVM. This supports the hypothesis that sorption of hydrophobic compounds is kinetically limited, and that dissolved organic matter is an interfering factor.
Frederick Johnson, Souding Li, Kai Su, Youxin Yuan, Israel Cabasso. Department of Chemistry, Polymer Research Institute, State University of New York College of Environmental Science and Forestry, Syracuse, NY 13210.
The advantage of operating PEM fuel cell units at high temperature has been recognized and proven by theoretical and practical studies. While operating at high temperature provides high-energy efficiency, it also reduces the external cooling load required by a fuel cell stack and preserves the catalytic activity of noble metal alloys.
Several new polymer electrolyte membranes have been synthesized, including: polymer blend membranes consisting of higher density, homogeneously, sulfonated poly(phenylene oxide) SPPO and Poly(vinylidene fluoride) PVF2, and high temperature proton transfer membranes of phosphonated poly(benzimidazole) PBI. The membranes have been extensively studied by impedance spectroscopy, DSC, NMR, FTIR and atomic force microscopy (AFM).
Membranes, including high temperature proton transfer membranes, show good PEM fuel cell performance with 2A/cm2 (at 0.5 V) at operating temperature 100oC. These PEM fuel cells show particularly good performance with air as the cathode feed . Durability testing of the blend membranes, with daily start-ups and shutdown has been conducted for greater than 30 days without a significant PEM fuel cell performance reduction. Membrane materials possess good mechanical strength and durability.
Mark J. Jordan, Ray C. VanOrden, David J. Kieber and Gregory L. Boyer. State University of New York College of Environmental Science and Forestry, Department of Chemistry, Syracuse, NY 13210
The hallucinogenic compounds psilocin and psilocybin occur naturally in several species of mushrooms. One example is the psilocybe genus. Because of their hallucinogenic effects, the United States controls these compounds, and possession of mushrooms of that genus is illegal. Currently, there is no useful method available for forensic scientists to quantify both psilocin and psilocybin in mushroom material. Therefore, we developed a reversed-phase high-performance liquid chromatography (RP-HPLC) technique with absorbance detection to quantify trace levels of these compounds in mushroom extracts. The first phase of this method development focused on the optimization of the chromatographic separation of psilocin and psilocybin. The chromatographic method was optimized comparing the separation of psilocin, psilocybin, and tryptamine (internal standard) using a variety of inorganic and organic pH buffers in the HPLC mobile phase, and examining the effect of buffer type, concentration and pH on the relative retention times of these compounds. When comparing the different buffers, it was observed that citric acid and trichloroacetic acid buffers gave the best peak shapes and separation, while formate yielded poor peak shapes and efficiencies. As then pH mobile phase increased, retention times decreased up to pH 6.0 and then increased at higher pHs except for psilocybin whose retention times continued to decrease. Retention times also decreased with an increase in buffer concentration, but with no change in selectivity. We also tested the affect of methanol and acetonitrile as an organic solvent in our mobile phase. A 10% acetonitrile/90% citric acid buffer mobile phase provided the best separation with a short analysis time. HPLC coupled with electrospray mass spectrometry was used for confirmation of peak identification. This optimized HPLC technique is sensitive and simple, and therefore it should allow for the routine analysis of extracted mushrooms for these compounds.
David R. Katz, and David J. Kieber. State University of New York College of Environmental Science and Forestry, Department of Chemistry, Syracuse, NY 13210
Nitrate is a limiting nutrient to algae in the marine photic zone. Loss of nitrate is not only limited to biological uptake, as some nitrate will undergo photochemical decomposition. Quantification of the production of nitrite from nitrate is important in understanding the nitrogen cycle in the ocean. Nitrate photolyzes in the UV (290-400 nm) with the maximum solar photolysis rate at 315 nm. Its photolysis partially results in the formation of nitrite ions. Typical quantum yields for nitrite formation fall in the range of 0.01 between 290 and 350 nm. This indicates that about 1 % of the photons absorbed by nitrate in solution produce nitrite. The quantum yield of nitrite production was monitored for changes influenced by temperature, initial nitrate concentration, and photon exposure. With the knowledge of how the quantum yield of nitrite changes under these conditions, fluctuations in nitrate and nitrite concentrations can be modeled throughout the marine photic zone.
Hsien Kung and Dr. Greg Boyer. Department of Chemistry, 337 Jahn Lab, SUNY College of Environmental Science and Forestry, Syracuse, NY 13210
Siderophores are low molecular weight compounds produced by many microorganisms as a means for obtaining iron from their surrounding environment. Ferricrocin (FCR) is a hydroxamate siderophore produced by the mycorrhizal fungus Aspergillus fumigatus as well as some Wilcoxina species. It forms part of a high affinity uptake mechanism for iron. The details of this mechanism are poorly understood. The purpose of this research was to prepare a radioactive siderophore analog that can be used to study siderophore-mediated uptake of metals. The first step was to design a protocol for the high-yield synthesis of such an analog. FCR was isolated by benzyl alcohol extractions from cultures of Aspergillus fumigatus grown under iron-limiting conditions. It was then purified by P2 size exclusion column chromatography, preparative HPLC, and characterized by high resolution nmr. Steglich esterification was used to prepare the acetate ester of FCR as a possible approach for labeling the siderophore. FCR was combined with acetic acid in dimethyl formamide (DMF). The addition of dimethyl aminopyridine (DMAP) and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) initiates the reaction. Thin layer chromatography was used to monitor the progress of the reaction. The reaction mixture was purified by C18 solid phase extraction, followed by prep HPLC. The product was characterized by UV-Vis spectroscopy, HPLC, mass spectroscopy and 1H NMR. To determine the optimum conditions for the reaction, the relative molar ratios of reactants were changed, and yields calculated. Ratios of 1:40, 1:400, and 1:4000 FCR:acetic acid were used giving yields of 86%, 55%, and <1%, respectively. The 1:40 ratio was also used to incorporate unlabeled 12C-sodium acetate into the siderophore. This ratio will be used to prepare radio-labeled FCR using 14C-labeled sodium acetate as a starting material. Future research will include degradation studies on the stability of this ester and using this labeled FCR to elucidate its role in fungal iron uptake.
Cynthia J. Lawniczak and Mark A. Teece, Faculty of Chemistry, 437 Jahn Lab, SUNY College of Environmental Science and Forestry, Syracuse, NY 13210.
All of the nutrients needed for the successful development of a turtle hatchling are contained in the egg. The majority of these nutrients, including protein, lipids, and metals, are found in the yolk. This study provided much needed information on the embryogenesis of the turtle. A complete understanding of the important nutrients needed and their metabolism during embryonic development becomes especially important in determining the possible causes of mortality in the nest. The metabolism of these essential nutrients was investigated throughout embryonic development. The concentration of amino acids was measured by HPLC. Lipids were separated by solid phase extraction and quantified by GC. Metals were analyzed after acid digestions by ICP. During the first part of growth, there was slow utilization of nutrients. The latter part of development, characterized by maximal growth of the embryo, showed rapid utilization of the protein, lipids, and metals. Also at this time, various changes were seen within the lipid classes. At the end of development, a residual yolk remained. Analysis of this hatchling yolk revealed a large percentage of energy in the form of triglycerides and free fatty acids which can be used to sustain the hatchling during the first few weeks of life as it emerged from the nest.
Kelly A. Lowe and John P. Hassett, Faculty of Chemistry, 435 Jahn Lab, SUNY College of Environmental Science and Forestry, Syracuse, NY 13210.
Mirex is a pollutant in Lake Ontario which indirectly photolyzes to photomirex. The residence time of mirex and photomirex in the water column can be estimated by combining the photolysis rate and the photomirex to mirex concentration ratio in the sediments. To determine the photolysis rate, grab samples of Lake Ontario water are fortified with mirex and irradiated in the laboratory. From these experiments, a “response function” is calculated, which describes the wavelength-dependent, intensity-normalized rate of the mirex photoreaction in Lake Ontario. This response function is combined with solar irradiation data and light attenuation data to calculate the rate of the reaction in the lake. Response functions for grab samples collected from June through October 2001 are similar throughout the season and are consistent with results for water collected in July 1998. The annual average whole lake rate constant is 0.6 yr-1. If the mirex to photomirex concentration ratio in the sediments represents the extent of reaction on an annual average basis, then the average residence time for mirex and photomirex is 0.2 year.
Meriah Neissel, Michael Satchwell, and Gregory Boyer, Chemistry Department, 341 Jahn Laboratory, SUNY College of Environmental Science and Forestry, Syracuse, NY 13210.
Industrial pollution, mining wastes, tailings and smelters can contaminate soils with high concentrations of heavy metals. This may inhibit the growth of vegetation in these areas. We are interested in promoting the successful colonization of ectomycorrhizal red pine on such spoils . To investigate the sensitivity of red pine seedlings to heavy metal toxicity, plants were grown without fungal or bacterial symbionts in a hydroponics system. Heavy metals (Cu, Zn, Cr, and Al) were added at concentrations ranging from 0.1 µM to 100µM (Cr), 1 µM to 1000 µM (Zn, Cu) and 0.01 mM to 10 mM (Al). Tolerance of non-mycorrhizal red pine was determined by measurements of root growth over a 36-day period and by the increase in dry weight at the end of the experiment. Localization of metals within the plant will be determined by ICP. The best growth was seen in plants grown at low concentrations (< 10 µM) of Cu and Zn. Red pine seedlings were moderately tolerant of Al up to 100 µM. They were very sensitive to Cr, even at the lowest concentration tested (0.1 µM). These results suggest that non-mycorrhizal red pine seedlings are sensitive to heavy metals in hydroponic cultures. The reported tolerance of red pine seedlings to heavy metals in field sites  suggest that other factors, such as mycorrhizal colonization and/or the metal speciation in the soil may play an important role in determining metal toxicity. Future research to investigate the effect of the production of metal chelating peptides by mycorrhizal fungi (siderophores) on the growth of red pines in situ and in plastico is in progress.
 Medve RJ, Sayre WG (1994) Heavy metals in red pines, basidiomycete sporocarps and soils on bituminous stripmine spoils. J Penn Acad Sci 68: 131-135
Jonathan Nuwer and Mark Teece, Chemistry Department, 437 Jahn Lab, SUNY College of Environmental Science and Forestry, Syracuse, NY 13210.
Biomarkers are organic compounds emitted to the environment that can be traced back to the specific type of organism from which they were originally synthesized. After being deposited as sediments, these compounds are well-preserved in the anoxic bottom waters of meromictic lakes. Environmental changes can have a dramatic effect on both terrestrial and aquatic species. Temporal changes in the relative abundance of organic biomarkers can indicate either natural or anthropogenic induced changes to the ecosystem. In this study the distribution of organic biomarkers over the past 1000 years is determined using a sediment core from Fayetteville Green Lake. The information collected will be used to determine whether small-scale climate oscillations such as the Little Ice Age affected the primary producers of the local watershed. In addition, the consequences of anthropogenic activities, such as deforestation and the construction of the Erie Canal, will be assessed.
Elizabeth A. Patchett and Gregory L. Boyer, Faculty of Chemistry, 341 Jahn Lab, SUNY-College of Environmental Science and Forestry, Syracuse, NY 13210.
The red tide alga, Alexandrium tamarense is a toxin-producing marine dinoflagellate that produces a series of potent neurotoxins. The toxins accumulate in shellfish feeding on the algae. Consumption of these toxic shellfish causes a condition known as paralytic shellfish poisoning or PSP, which can be fatal to humans and marine life. Very little is known about the environmental factors that cause a red tide, or their effect on PSP toxin formation. We are determining the role of trace metals, specifically iron, on the growth and toxicity of this organism. Alexandrium tamarense was grown under trace metal clean conditions in polycarbonate flasks containing artificial seawater with iron added at concentrations ranging between 0 and 1000nM. Growth was measured by in vivo fluorescence and cell counts. HPLC coupled with a post column reactor and fluorescent detection (HPLC-PCRS) was used to measure total toxin content and to quantify the amounts and types of individual PSP toxin isomers. Preliminary data indicates that Alexandrium grows best in seawater containing 100-1000 nM iron-EDTA. Large amounts of neosaxitoxin and gonyautoxins have been detected in these cultures. Determination of the changes in the toxin profile with iron limitation is presently in progress. Cultures in 10nM iron-EDTA have formed resting cysts and did not show a marked increase in fluorescence. Examination of the complex relationship between growth, toxicity, and environmental nutrient conditions are still currently in progress.
Adam Penque and Dr Mark Teece, Department of Chemistry, 437 Jahn Laboratory, SUNY College of Environmental Science and Forestry, Syracuse NY 13210.
The Red Knot Calidris canutus is a shore bird indigenous to Chile, annually migrating to the Arctic Circle to breed. Along this migration the Red Knot stops once in North America’s Delaware Bay, a stop that coincides with the bay’s mass spawning of horseshoe crabs (Limulus polyphemus). Arriving emaciated the birds gorge themselves exclusively on these crab eggs, storing the valuable nutrients for continued migration and the breeding season.
Current research is focused on elucidating the metabolism of the Red Knot, with particular emphasis on the metabolism these horseshoe crab eggs. GC/FTIR comparison of the phospholipid, monoglyceride, diglyceride, and free fatty acid concentrations per tissue between birds arriving and leaving the bay confirms the importance of the crab eggs as a source of nutrients for the migration and breeding. Furthermore, changes in percent protein concentration per tissue type shows specifically how the bird delegates these proteins for use in migration and breeding. These preliminary results Further support the importance of Delaware Bay as a staging area for Red Knot migration by identifying the horseshoe crab as a vital food source.
Jocelyn M. Polito, John P. Hassett, SUNY Environmental Science and Forestry, Syracuse, NY
Many hydrophobic pollutants of environmental concern are found in low concentrations in natural waters, so conventional grab samples can not detect them. PISCES is a passive in-situ concentration extraction sampler. It provides a time averaged sample of the water of interest and allows lower detection limits than grab samples, since a larger volume of water is effectively sampled. PISCES concentrates hydrophobic organic compounds by diffusion from the water, across a polymer membrane and into a reservoir of organic solvent. The sampling rate of PISCES can vary by compound and also depends on the temperature and degree of turbulence of the water sampled. The higher the temperature the faster compounds enter the PISCES. Temperature calibrations were performed for the rate that PISCES samples polycyclic aromatic hydrocarbons (PAH): naphthalene, acenaphthene, acenaphthylene, anthracene, benzo [a] anthracene, benzo [a] pyrene, benzo [b] flouranthene, benzo [k] fluoranthene, chrysene, fluoranthene, fluorene, naphthalene, phenanthrene and pyrene. Sampling rates are approximately 1 L per day for field samplers with 57 cm2 membrane areas. Preliminary work to study the effects turbulence on sampling rate has also been performed. Increasing of turbulence has been shown to increase sampling rate at least an order of magnitude.
Joseph W. Ryan*, Kevin Lambrych*, Ivan Gitsov*, Stewart Tanenbaum*, James Nakas** *Faculty of Chemistry, 117 Jahn Laboratory, SUNY College of Environmental Science and Forestry, Syracuse, NY 13210. **Faculty of Biology, 201 Illick Hall, SUNY College of Environmental Science and Forestry, Syracuse, NY 13210.
The appearance of polycyclic aromatic hydrocarbons (PAH’s) like benzo-a-pyrene in drinking water has led to a demand for an efficient way of removal. If benzo-a-pyrene is oxidized to its dione form, bacteria could potentially consume it thus removing it from the system.
The enzyme Laccase has been proven to posses very sufficient oxidative capabilities toward phenolic compounds . In the presence of a redox mediator, laccase has also shown the ability to oxidize some non phenolics. The very low solubility of benzo-a-pyrene causes problems for this oxidation reaction by the water soluble enzyme. Previous studies have shown that a linear dendritic copolymer of polyethylene glycol (5000 g/mol) and polyhydroxy benzyl ether has the capability of coating carbohydrate surfaces such as the ones in the enzyme  and encapsulating PAH’s in aqueous media . UV-vis spectroscopy has shown that combination of the enzyme and substrate by the copolymer and the addition of a redox mediator allow for sufficient oxidation to occur.
. Miller J, Olejnik D (2000) Photolysis of Polycyclic Aromatic Hydrocarbons in Water. WAT RES 35 (1): 233-243
2. Collins P, Kotterman M, et al. (1996) Oxidation of Anthracene and Benzo-a-pyrene by Laccases from Trametes versicolor. APPL ENVIRON MICROBIOL 62 (12): 4563-4567
3. Frechet J, Gitsov I, et al (1999) Modification of Surfaces and Interfaces by Non-covalent Assembly of Hybrid Linear-Dendritic Block Copolymers: Poly(benzyl ether) Dendrons as Anchors for Poly(ethylene glycol) Chains on Cellulose or Polyester. CHEM MATER 11: 1267
4. Gitsov I, Lambrych K, et al. (2000) Micelles with Highly Branched Nanoporous Interior: Solution Properties and Binding Capabilities of Amphiphilic Copolymers with Linear Dendritic Architecture.
Tariq Shaheed, Dr. Greg Boyer, and Mike Satchwell, Department of Chemistry, 341 Jahn Lab, SUNY College of Environmental Science and Forestry, Syracuse, NY 13210
The ectendomycorrhizal fungus Wilcoxina mikolae produces the siderophore ferricrocin under iron-limited conditions. Siderophores are bioactive peptides that are highly specific for ferric iron, but can also bind other heavy metals. In nature W. mikolae grows symbiotically with red pine (Pinus resinosa). We hope to use mycorrhizal red pine to remediate soils contaminated by heavy metals. An obstacle to this research is that siderophore production in W. mikolae is inhibited at an iron concentration below 100ppb. For remediation purposes, we need a W. mikolae mutant where siderophore biosynthesis is constitutively expressed. Towards that goal, we have been developing an in situ agar assay that can be used to detect constitutive siderophore production. A blue iron-containing dye, Chrome Azurol S was incorporated into MMN agar plates without added iron and inoculated with W. mikolae. After 7 days, the growing colonies were surrounded by a yellow halo where fungal siderophore production removed the iron(III) from the dye complex. The second part of this project will involve mutating W. mikolae with N’-methyl-N’-nitro-N-nitrosoguanidine (NTG) and screening these mutants for siderophore production under iron replete conditions using this CAS assay. The putative target of the mutation is a region of genomic DNA similar to that identified in the smut fungus, Ustilago maydis. This gene, urbs1, regulates siderophore biosynthesis; it has an intronless open reading frame that specifies a protein of 950 amino acids containing two zinc finger motifs similar to the GATA family of transcription factors . This family of transcription factors has zinc finger motifs that are associated with iron metabolism in vertebrates and can be related to iron regulation in other organisms.
1. C. Voisard, J. Wang, J.L. McEvoy, P. Xu, and S.A. Leong (1993) Mol. Cell. Biol. 13:7091-7100
Peter Smyntek and Mark Teece. Department of Chemistry, 437 Jahn Lab, SUNY-College of Environmental Science and Forestry, Syracuse, NY 13210.
Stable isotopes, particularly 13C and 15N, are becoming increasingly utilized in ecological and environmental studies that focus on assessing animal diet and food web dynamics. Their utility stems from the fact that the 13C value of an organism’s tissue reflects the carbon source of its diet, while the organism’s tissue 15N value indicates the trophic position of the organism within a given food web. Therefore, measurements of the 13C and 15N isotope values of a group of organisms can provide a practical way of evaluating the structure of food webs, especially those that may be very difficult to assess by conventional methods such as gut contents analysis. Researchers have applied stable isotope techniques to demonstrate diet shifts in native fish populations due to the proliferation of invasive fish species. Due to their far-reaching potential, stable isotope approaches should become more prevalent in future food web studies.
Xiaoling Wang and Avik P. Chatterjee, Department of Chemistry, 121 Edwin C. Jahn Laboratory, SUNY-ESF, Syracuse, NY 13210.
We investigate geometrical percolation in (i) one-component systems of linear macromolecules with different degrees of flexibility, as well as (ii) athermal mixtures of semiflexible and rod-like polymers. The volume fraction at the percolation threshold depends strongly on macromolecular architecture and size. Attractive inter-segmental interactions are included in our treatment of flexible polymers, and are shown to have a pronounced effect on the threshold volume fraction in the vicinity of the theta temperature. The percolation threshold for rod-like particles dispersed in a medium of flexible polymers is investigated as a function of the particle aspect ratio. The dependence of critical volume fraction on rod aspect ratio is strikingly similar to that found for the analogous one component model. The primary effect of explicitly including the flexible matrix polymer molecules is a reduction of the critical volume fraction by a factor which depends only weakly on the particle aspect ratio.
Xingye Yang, Michael F. Satchwell, and Gregory L. Boyer, Faculty of Chemistry, 337 Jahn Lab, SUNY College of Environmental Science and Forestry, Syracuse NY 13210
Anatoxin-a is a potent cyanobacterial neurotoxin and can cause great environmental and human health risk. Anabaena sp. is the most common anatoxin-a producer and is widely distributed in New York State waters. In this research, several Anabaena sp. have been cultured and analyzed to determine whether they produce anatoxin-a. Anabaena species were grown in 8 L cultures in BG-11 media with aeration. After two-week incubation, the cells were harvested by centrifugation and freeze-dried. After extraction in 50% methanol and derivatization by NBD-F, HPLC with fluorescence detector (HPLC-FD) was used for detection of anatoxin-a. LCMS was also used for confirmation of anatoxin-a presence. It was found that under experimental conditions, Anabaena flos-aquae (Lyng.) Breb. (UTEX LB2383) produces anatoxin-a while no anatoxin-a production was detected in the other Anabaena sp., indicating potential toxin threat.
James, K. J., Sherlock, I.R., Stack, M. A. 1997. Toxicon, 35:963-971
Harada, K., Kimura, Y., Ogawa, K., etc. 1989. Toxicon, 27:1289-1296
Shengbin Zhang, Arthur Stipanovic and William T. Winter, Department of Chemistry and the Cellulose Research Institute, SUNY-College of Environmental Science and Forestry, Syracuse, NY 13210.
Electrorheological and magnetorheological fluids (ERFs and MRFs) are “smart materials” which can reversibly transform from liquid to quasi-solid state on a millisecond scale under the stimuli of electric or magnetic fields. Their response to input stimuli in real time enable them to be applied in the mechanical devices.
The basic compositions of fluids are electrically or magnetically polarizable particles and base fluids. Cellulose is one of the most abundant natural materials in the world. Topochemical modified cellulose sulfate (CS) and diethylaminoethyl (DEAE) cellulose particles with different degree of substitution can be polarized in the electric fields. The rheological and electrical properties of fluids based on CS and DEAE cellulose particles in the various electric fields were studied. They have potential to be used in ERFs.
The composites of pulp and ferrite were synthesized via in-situ method. The potential of the application of this composite in the magnetorheological fluids was discussed.
Guozhang Zou and Gregory L. Boyer
Ferricrocin is a cyclic peptide ferric siderophore. It contains three hydroxamate groups coordinated with ferric iron. Aqueous and solid phase chemistry have measured binding interactions between desferriferricrocin, iron-free ferricrocin, and Fe(III). This interaction is based on the complex formed between the three hydroxamate groups of desferriferricrocin and ferric iron. Very few studies have been done to measure interactions between ferricrocin and metal ions. By using LCMS, we discovered complexes formed between ferricrocin and both Cu(II) and Zn(II). Cu(II) and Zn(II) complexes were detected as singly positively charged MH+ ions. Cu(II) and Zn(II) were able to displace amide protons from ferricrocin and form complexes with the deprotonated ferricrocin. Cu(II) complex was produced more efficiently from Electrospray ionization (ESI) than Zn(II) complex. ESI provided a unique method to study the intrinsic intermolecular interaction between siderophores and metal ions.