Chemicals and Drugs Commons^™

Enzymatic Hydrolysis Of Biomass At High-Solids Loadings – A Review, Alicia A. Modenbach, Sue E. Nokes

Biosystems and Agricultural Engineering Faculty Publications

Enzymatic hydrolysis is the unit operation in the lignocellulose conversion process that utilizes enzymes to depolymerize lignocellulosic biomass. The saccharide components released are the feedstock for fermentation. When performed at high-solids loadings (≥ 15% solids, w/w), enzymatic hydrolysis potentially offers many advantages over conversions performed at low- or moderate-solids loadings, including increased sugar and ethanol concentrations and decreased capital and operating costs.

The goal of this review is to provide a consolidated source of information on studies using high-solids loadings in enzymatic hydrolysis. Included in this review is a brief discussion of the limitations, such as a lack of available …

Effects Of Intranasally Administered Dnsp-11 On The Central Dopamine System Of Normal And Parkinsonian Fischer 344 Rats, James H. Sonne

Theses and Dissertations--Neuroscience

Due to the blood-brain barrier, delivery of many drugs to the brain has required intracranial surgery which is prone to complication. Here we show that Dopamine Neuron Stimulating Peptide 11 (DNSP-11), following non-invasive intranasal administration, protects dopaminergic neurons from a lesion model of Parkinson’s disease in the rat. A significant and dose-dependent increase in an index of dopamine turnover (the ratio of DOPAC to dopamine) was observed in the striatum of normal young adult Fischer 344 rats by whole-tissue neurochemistry compared to vehicle administered controls.

Among animals challenged with a moderate, unilateral 6-hydroxy-dopamine (6-OHDA) lesion of the substantia nigra, those …

Synthesis And Stability Studies Of Prodrugs And Codrugs Of Naltrexone And 6-Β-Naltrexol, Joshua A. Eldridge

Theses and Dissertations--Pharmacy

The present study was divided between two different drug delivery goals, each involving naltrexone (NTX) or its active metabolite, 6-β-naltrexol (NTXOL). First, amino acid esters of NTX and NTXOL were prepared in order to test their candidacy for microneedle-enhanced transdermal delivery. Second, a 3-O-(-)-cytisine-naltrexone (CYT-NTX) codrug was prepared for screening as a potential oral delivery form of NTX and (-)-cytisine (CYT). The amino acid prodrugs were intended for the treatment of alcohol abuse, while the codrug was designed as a single agent for the treatment of alcoholism and tobacco-dependency co-morbidities. One hypothesis of this work was that prodrugs …

Biosynthetic Pathway Of The Aminoribosyl Component Of Lipopeptidyl Nucleoside Antibiotics, Xiuling Chi

Theses and Dissertations--Pharmacy

Several lipopeptidyl nucleoside antibiotics that inhibit bacterial translocase I (MraY) involved in peptidoglycan cell wall biosynthesis contain an aminoribosyl moiety, an unusual sugar appendage in natural products. A-90289 and muraminomicin are the two representative antibiotics that belong to this family. Bioinformatic analysis of the biosynthetic A-90289 gene clusters revealed that five enzymes are likely involved in the assembly and attachment of the aminoribosyl unit. These enzymes of A-90289 are functionally assigned by in vitro characterization. The results reveal a unique ribosylation pathway that highlighted by uridine-5′-monophosphate as the source of the sugar, a phosphorylase strategy to generate a sugar-1-phosphate, and …

A Novel Selective Lipid Uptake Pathway Contributing To Ldl-Induced Macrophage Foam Cell Formation, Jason M. Meyer

Theses and Dissertations--Molecular and Cellular Biochemistry

Atherosclerosis is a disease characterized by cholesterol-rich plaques within the intima of medium and large arteries. Cholesterol deposition is thought to occur by infiltration of low-density lipoprotein (LDL) into lesions followed by uptake into macrophages, generating lipid-loaded “foam cells.” Foam cells can also be generated in vitro by treatment of macrophages with LDL or oxidized LDL (oxLDL). The purpose of the current investigation was to determine the contribution of selective cholesteryl ester (CE) uptake versus whole-particle uptake during LDL-induced foam cell formation in cultured macrophages. Murine bone marrow-derived macrophages (BMMs) exhibited significant cholesterol accumulation when treated with LDL as indicated …

The Mesocorticolimbic Dopamine Pathway Reconstituted In Vitro: Glutamate Receptors And Corticosteroid-Methamphetamine Neurotoxicity, Jennifer N. Berry

Theses and Dissertations--Psychology

Stress promotes the use of methamphetamine and other recreational substances and is often implicated in relapse to stimulant use. Thus, it is of critical importance to examine the consequences of the co-occurance of stress and methamphetamine use. Activity of the glutamatergic N-methyl D-aspartate (NMDA) receptor system appears to be involved in the neurotoxic effects of both chronic stress and methamphetamine exposure. The current studies investigated the hypothesis that chronic pre-exposure to the stress hormone corticosterone (CORT) results in an increase of NMDA receptor activity and that this will potentiate the neurotoxic effects of methamphetamine (METH). Co-cultures of the …

Borrelia Burgdorferi Cp32 Bpab Modulates Expression Of The Prophage Nucp Nuclease And Ssbp Single-Stranded Dna-Binding Protein, Alicia M. Chenail, Brandon L. Jutras, Claire A. Adams, Logan H. Burns, Amy Bowman, Ashutosh Verma, Brian Stevenson

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The Borrelia burgdorferi BpaB proteins of the spirochete's ubiquitous cp32 prophages are DNA-binding proteins, required both for maintenance of the bacteriophage episomes and for transcriptional regulation of the cp32 erp operons. Through use of DNase I footprinting, we demonstrate that BpaB binds the erp operator initially at the sequence 5′-TTATA-3′. Electrophoretic mobility shift assays indicated that BpaB also binds with high affinity to sites located in the 5′ noncoding regions of two additional cp32 genes. Characterization of the proteins encoded by those genes indicated that they are a single-stranded DNA-binding protein and a nuclease, which we named SsbP and NucP, …

Effects Of Methoprene On The Survivorship Of Adult Aedes Mosquitoes: A Strategy Or Inactivating Released Mosquitoes, Peter J. Brabant Iii

Theses and Dissertations--Entomology

Methoprene is a Juvenile Hormone (JH) analogue commonly used for the control of mosquito larvae. When applied to a mosquito breeding site, methoprene enters the haemolymph, where it mimics the function of JH and interferes with normal metamorphosis, resulting in larval mortality. Methoprene is commonly used for the control of larvae and has not been used as an adulticide, due to an absence of acute effects. This study evaluated possible chronic effects caused by the exposure of adult Aedes mosquitoes to methoprene. Methoprene was applied, in both technical grade and the commercially available Altosid®, topically to adults through droplet application …

Enantioselective Demethylation: The Key To The Nornicotine Enantiomeric Composition In Tobacco Leaf, Bin Cai

Theses and Dissertations--Plant and Soil Sciences

Nicotine and nornicotine are the two main alkaloids that accumulate in Nicotiana tabacum L. (tobacco), and nornicotine is the N-demethylation metabolite of nicotine. Nicotine is synthesized in the root, and probably primarily in the root tip. Both nicotine and nornicotine exist as two isomers that differ from each other by the orientation of H atom at the C-2' position on the pyrrolidine ring. (S)-nicotine is the dominant form in tobacco leaf and the enantiomer fraction of nicotine (EF_nic), the fraction of (R)-enantiomer over the total nicotine, is approximately 0.002. Despite considerable efforts to elucidate nicotine and nornicotine …

Multimeric Hemicellulases Facilitate Biomass Conversion, Zhanmin Fan, Kurt Wagschal, Wei Chen, Michael D. Montross, Charles C. Lee, Ling Yuan

Plant and Soil Sciences Faculty Publications

Two highly active trifunctional hemicellulases were constructed by linking the catalytic portion of a xylanase with an arabinofuranosidase and a xylosidase, using either flexible peptide linkers or linkers containing a cellulose-binding domain. The multifunctional enzymes retain the parental enzyme properties and exhibit synergistic effects in hydrolysis of natural xylans and corn stover.

A Case-Control Study Of Farming And Prostate Cancer In African-American And Caucasian Men, Tamra E. Meyer, Ann L. Coker, Maureen Sanderson, Elaine Symanski

CRVAW Faculty Journal Articles

Objective: To determine the risk of prostate cancer associated with farming by duration, recency and specific activities among African-Americans and Caucasians.

Methods: This population-based case–control study had information on farming-related activities for 405 incident prostate cancer cases and 392 controls matched for age, race and region in South Carolina, USA, from 1999 to 2001. Cases with histologically confirmed, primary invasive prostate cancer who were aged between 65 and 79 years were ascertained through the South Carolina Central Cancer Registry. Appropriately matched controls were identified from the Health Care Financing Administration Medicare Beneficiary File. Data were collected using computer-assisted telephone interviewing, …

Optimization Of Solid-State Fermentation Parameters For The Production Of Xylanase By Trichoderma Longibrachiatum On Wheat Bran In A Forced Aeration System, Elizabeth R. Ridder, Sue E. Nokes, Barbara L. Knutson

Biosystems and Agricultural Engineering Faculty Publications

The effect of aeration on the production of xylanase by Trichoderma longibrachiatum on wheat bran in a solid-state fermentation (SSF) system has not been investigated. This study was conducted to investigate the interactive effects of aeration, initial moisture content of the substrate, and depth of the substrate on xylanase activity produced in a tray fermenter. The experiment was conducted as a split plot experiment with factorial treatments and three replications of each treatment combination. The whole plot treatment was aeration rate (0, 2.9, 5.7 L/min/kg bran). Initial moisture content (45, 55, 65% w.b.) and depth of substrate (1.0 and 2.5 …

Optimization Of Solid-State Fermentation Parameters For The Production Of Xylanase By Trichoderma Longibrachiatum On Wheat Bran, Elizabeth R. Ridder, Sue E. Nokes, Barbara L. Knutson

Biosystems and Agricultural Engineering Faculty Publications

Solid-state fermentation has the potential to produce inexpensive enzymes for use in high-volume industrial applications. Process parameters such as substrate moisture content and length of fermentation can have a significant effect on the amount and timing of enzyme production. This study was conducted in two stages, a screening stage and an optimization stage, to determine the effects of moisture content of the substrate, surfactant addition upon inoculation, depth of the substrate, and duration of fermentation on xylanase activity produced by Trichoderma longibrachiatum. Screening fermentations were conducted at 25°C, 50 and 75% wet basis moisture content (w.b.), 0.0 and 0.2% …

The Aquatic Toxicity Of Organic Compounds To Embryo-Larval Stages Of Fish And Amphibians, Jeffrey A. Black, Wesley J. Birge, Willaim E. Mcdonnell, Albert G. Westerman, Barbara A. Ramey, Donald M. Bruser

KWRRI Research Reports

Aquatic toxicity tests were conducted on 11 organic compounds considered hazardous to water resources. The toxicity of each compound was evaluated using embryo-larval stages of two to eight fish and amphibian species. Exposure was initiated at fertilization and maintained through 4 days posthatching. The animal test species exhibited varying degrees of sensitivity to the selected toxicants. Combined frequencies for mortality and teratogenesis at 4 days posthatching gave LC₅₀ ranges of 3.66 to 8.25 mg/L for benzene, 1.16 to 22.42 mg/L for carbon tetrachloride, 0.11 to 1.20 mg/L for chlorobenzene, 2.03 to > 68 mg/L for chloroform, 3.01 to 5.56 mg/L …

Low Pressure Membrane Separation Process To Remove Heavy Metal Complexes, Dibakar Bhattacharyya, Chin-Shun Cheng

KWRRI Research Reports

The overall objective of this investigation is to establish the rejection behavior of heavy metals in the presence of complexing agents, utilizing negatively charged ultrafiltration membranes. An extensive experimental investigation is conducted with Zn²⁺, Cd²⁺, Cu²⁺, and Cu¹⁺ in the presence of cyanide, ethylenediamine tetraacetic acid, and oxalates, under insignificant concentration polarization condition. The rejection dependence of the heavy metals is found to be a function of feed metal concentration, metal types, complexing agent to metal feed molar ratio, pH and ionic strength. The dependence of rejection behavior of heavy metals and complexing …

An Avoidance Response Bioassay For Aquatic Pollutants, Jeffrey A. Black, Wesley J. Birge

KWRRI Research Reports

Avoidance response bioassays were conducted with eight aquatic contaminants, including cadmium, copper, mercury, zinc, chloroform, dioctyl phthalate (DOP), trisodium nitrilotriacetic acid (NTA), and phenol. Tests were performed in a dual-channel fluviarium system, and the toxicant injection procedure used provided good regulation of exposure concentrations. Juvenile stages of largemouth bass (Micropterus salmoides), bluegill sunfish (Lepomis macrochirus), and rainbow trout (Salmo gairdneri), and tadpoles of the American toad (Bufo americanus) proved to be suitable animals for evaluating avoidance or attraction responses. The trout was the most sensitive species tested.

Avoidance was significant in tests …

Effects Of Organic Compounds On Amphibian Reproduction, Wesley J. Birge, Jeffrey A. Black, Robert A. Kuehne

KWRRI Research Reports

Aquatic toxicity tests were conducted with atrazine, carbon tetrachloride, chloroform, methylene chloride, trisodium nitrilotriacetic acid (NTA), and phenol. Each compound was administered to developmental stages of three to five amphibian species. Exposure was initiated at fertilization and maintained through 4 days posthatching. Test responses included lethality and teratogenesis. Different amphibian species exhibited varying degrees of tolerance to the selected compounds. Greatest tolerance usually was observed for the more broadly adapted semi-aquatic and terrestrial species (e.g., Bufo americanus, Bufo fowleri). The more sensitive amphibians usually included those species which normally are restricted to aquatic or moist habitats (e.g., Rana …

Procedures For Trace Analysis Of Dissolved Inorganic And Organic Constituents In Water, Gary D. Christian, Charles E. Matkovich, W. Lynn Schertz

KWRRI Research Reports

A study of different solvent systems for the atomic absorption determination of cobalt revealed that acetone results in best sensitivity. Acetone is the solvent of choice for the sensitive measurement of several metals. Hence, methods were investigated for the separation of acetone from water by salting out so that possible solvent extraction of metal chelates into this solvent could be performed. About two-thirds saturated calcium chloride proved to be the best system for salting out of the acetone. It is essentially a neutral salt and is in general a weakly complexing salt, resulting in minimum interference in solvent extractions. Solvent …