Biological Engineering Commons^™

Cationic Starch Synthesis, Development, And Evaluation For Harvesting Microalgae For Wastewater Treatment, Renil John Anthony

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Microalgae are the preferred crop for the production of biodiesel. Microalgae are microplants that have the ability to harness sunlight more efficiently than other plants and store 20-80% lipids per g of dry algae in their cells. Microalgae have the extraordinary ability to grow in brackish water or wastewater. Microalgae can be grown in municipal wastewater to uptake phosphorus and nitrogen and remediate the wastewater of these nutrients. Microalgae thus cultivated accomplishes a dual role of wastewater treatment and provides a sustainable feedstock for biofuels and other bioproducts.

This study focused on efficiently harvesting microalgae from water using modified starch. …

Optimization Of Polyhydroxybutyrate Production In Recombinant Escherichia Coli Through Metabolic Modeling And Simulation, Yoshitaro Heshiki

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The objective of this study is to optimize the growth media and genes to maximize PHB production computer simulations, and to evaluate the simulation results through experiments. In order to achieve this objective, the metabolism of E. coli that produces PHB was modeled using the existing E. coli genome-scale metabolic networks. To identify the best additional nutrient for PHB production, carbon sources, minerals, amiano acids, nitrogen sources, and sulfur sources were examined by production potential analysis. Strain design was conducted to find the unwanted reactions to overexpress PHB synthesis pathway.

Department Of Biological Systems Engineering Newsletter, Volume 7, Number 2, April 2013

BSE Department Magazine

No abstract provided.

Atypical Glycolysis In Clostridium Thermocellum, Jilai Zhou, Daniel G. Olson, D. Aaron Argyros, Yu Deng, Walter M. Van Gulik, Johannes P. Van Dijken, Lee R. Lynd

Dartmouth Scholarship

Cofactor specificities of glycolytic enzymes in Clostridium thermocellum were studied with cellobiose-grown cells from batch cultures. Intracellular glucose was phosphorylated by glucokinase using GTP rather than ATP. Although phosphofructokinase typically uses ATP as a phosphoryl donor, we found only pyrophosphate (PPi)-linked activity. Phosphoglycerate kinase used both GDP and ADP as phosphoryl acceptors. In agreement with the absence of a pyruvate kinase sequence in the C. thermocellum genome, no activity of this enzyme could be detected. Also, the annotated pyruvate phosphate dikinase (ppdk) is not crucial for the generation of pyruvate from phosphoenolpyruvate (PEP), as deletion of the ppdk gene did …

Surface- And Hydrogel-Mediated Delivery Of Nucleic Acid Nanoparticles, Angela K. Pannier, Tatiana Segura

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Gene expression within a cell population can be directly altered through gene delivery approaches. Traditionally for nonviral delivery, plasmids or siRNA molecules, encoding or targeting the gene of interest, are packaged within nanoparticles. These nanoparticles are then delivered to the media surrounding cells seeded onto tissue culture plastic; this technique is termed bolus delivery. Although bolus delivery is widely utilized to screen for efficient delivery vehicles and to study gene function in vitro, this delivery strategy may not result in efficient gene transfer for all cell types or may not identify those delivery vehicles that will be efficient in vivo. …

The Effects Of Hydrostatic Pressure On Early Endothelial Tubulogenic Processes, Ryan M. Underwood

Theses and Dissertations--Biomedical Engineering

The effects of mechanical forces on endothelial cell function and behavior are well documented, but have not been fully characterized. Specifically, fluid pressure has been shown to elicit physical and chemical responses known to be involved in the initiation and progression of endothelial cell-mediated vascularization. Central to the process of vascularization is the formation of tube-like structures. This process—tubulogenesis—is essential to both the physiological and pathological growth of tissues. Given the known effects of pressure on endothelial cells and its ubiquitous presence in the vasculature, we investigated pressure as a magnitude-dependent parameter for the regulation of endothelial tubulogenic activity. To …

Metacom: Automated Data Processing And Analysis Of Metagenomic Community Sequences, Cody A. Tramp, Charles D. Miller

Browse all Datasets

Advances in next generation sequencing technology have allowed metagenomic researchers to study the composition of bacterial communities through analysis of the vast numbers of sequence reads that these technologies generate. It is not feasible to analyze and interpret this large amount of data manually and individual research groups must create automated scripts and programs to analyze this data. Here, we present MetaCom, a program that offers a common set of analysis and organizational tools that can be used by research groups in the analysis of environmental samples. MetaCom is an open-source software tool that can process next generation sequencing output, …

Noninvasive Near-Infrared Diffuse Optical Monitoring Of Cerebral Hemodynamics And Autoregulation, Ran Cheng

Theses and Dissertations--Biomedical Engineering

Many cerebral diseases are associated with abnormal cerebral hemodynamics and impaired cerebral autoregulation (CA). CA is a mechanism to maintain cerebral blood flow (CBF) stable when mean arterial pressure (MAP) fluctuates. Evaluating these abnormalities requires direct measurements of cerebral hemodynamics and MAP. Several near-infrared diffuse optical instruments have been developed in our laboratory for hemodynamic measurements including near-infrared spectroscopy (NIRS), diffuse correlation spectroscopy (DCS), hybrid NIRS/DCS, and dual-wavelength DCS flow-oximeter. We utilized these noninvasive technologies to quantify CBF and cerebral oxygenation in different populations under different physiological conditions/manipulations. A commercial finger plethysmograph was used to continuously monitor MAP. For investigating …

Bacillus Thuringiensis: Transgenic Crops, Julie A. Peterson, John J. Obrycki, James D. Harwood

Department of Entomology: Faculty Publications

Bacillus thuringiensis (Bt) crops, genetically modified to express insecticidal toxins that target key pests of corn, cotton, rice, potato, and other crops, have been rapidly adopted and have become dominant fixtures in agroecosystems throughout the world. Due to the constitutive nature of Bt toxin expression, insecticidal proteins may be found in nearly all plant tissues, presenting multiple sources for Bt toxins to enter the environment, thus creating complex direct and indirect pathways for non-target organisms to be exposed to insecticidal proteins. The environmental impacts of Bt crops have been widely debated, although both benefits and risks do exist. Benefits of …

A Watershed Scale Evaluation Of Selected Second Generation Biofeedstocks On Water Quality, Gurdeep Singh

Graduate Theses and Dissertations

This study compares a novel simulation approach to the conventional Soil and Water Assessment Tool (SWAT) modeler's approach for targeting biofuel crop production on marginal lands. In conventional SWAT modeling approach, non-spatial definition of hydrological response units (HRUs) results in the simulation of biofuel crops on both marginal and non-marginal land. This study provides an alternative approach in which a marginal-land raster was integrated into the land use and land cover (LULC) raster in such a way that the land uses were divided into marginal and non-marginal components. This modified LULC was used for model setup which resulted in marginal …

Morphometric, Biochemical, And Raman Spctral Analyses Of Muscle Damage In Patients With Peripheral Arterial Disease: Provising Objective Criteria For Diagnosis And Treatment Monitoring, Kim Cluff

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Peripheral arterial disease (PAD), which affects approximately 10 million Americans, is characterized by atherosclerosis of the non-coronary arteries. PAD produces a progressive accumulation of ischemic injury to the limbs that is reflected in a gradual worsening in the myofiber morphology and oxidative damage in the gastrocnemius muscle. In this study, we evaluated the hypothesis that quantitative morphological and biochemical parameters of gastrocnemius myofibers change in a consistent manner during the progression of PAD, provide an objective grading of muscle degeneration in the ischemic limb, and correlate to clinical stage of PAD. Myofiber morphometrics were determined precisely with mathematical equations that …

Design Of A Pretreatment And Enzymatic Saccharification Scheme Of Understory From Managed Pine Forest For A Biochemical-Refinery Platform: The Example Of The Sweetgum Tree, Angele Djioleu

Graduate Theses and Dissertations

The possibility of using sweetgum from southern pine dominated forests as a biobased refinery feedstock was investigated. First, a baseline hydrolysis scheme for sweetgum wood and bark was designed. Sweetgum wood and bark were pretreated with 0.98% (v/v) sulfuric acid at 140°C for 30, 40, 50, 60 or 70 min and at 160°C for 30, 40, 50 or 60 min. The water insoluble solid (WIS) fraction was hydrolyzed with a cellulase enzyme cocktail. Results showed that maximum xylose and glucose yields from the wood were 82 and 86%, respectively. Similarly, the respective maximum yields of xylose and glucose from the …

Biodiesel Production From Mixed Culture Algae Via A Wet Lipid Extraction Procedure, Ashik Sathish

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Development of renewable sources of energy has received significant interest due to the rising costs of energy and the environmental impact of using fossil fuels. Biodiesel production from renewable sources of oil has shown promise of helping to replace or reduce dependence on petroleum based diesel thereby reducing demand for crude oil. Microalgae have been considered as a strong candidate for the production of large quantities of renewable oil for biodiesel production.

Microalgae are single cell photosynthetic organisms that posses the capability to produce renewable oil at rates much faster than land based plants and crops. In addition, microalgae can …

Characterization Of Xylan Utilization And Discovery Of A New Endoxylanase In Thermoanaerobacterium Saccharolyticum Through Targeted Gene Deletions, Kara K. Podkaminer, Adam M. Guss, Heather L. Trajano, David A. Hogsett, Lee R. Lynd

Dartmouth Scholarship

The economical production of fuels and commodity chemicals from lignocellulose requires the utilization of both the cellulose and hemicellulose fractions. Xylanase enzymes allow greater utilization of hemicellulose while also increasing cellulose hydrolysis. Recent metabolic engineering efforts have resulted in a strain of Thermoanaerobacterium saccharolyticum that can convert C5 and C6 sugars, as well as insoluble xylan, into ethanol at high yield. To better understand the process of xylan solubilization in this organism, a series of targeted deletions were constructed in the homoethanologenic T. saccharolyticum strain M0355 to characterize xylan hydrolysis and xylose utilization in this organism. While the deletion of …

Analysis Of The Effect Of Feeding Regimen On Gh/Igf Axis In Channel Catfish (Ictalurus Punctatus), Samantha Puckett

Biological and Agricultural Engineering Undergraduate Honors Theses

Channel catfish (Ictalurus punctatus) are the most widely farmed aquatic animal in the United States. Assessing the effect of feeding regimens on their overall growth requires grow-out trials and a subsequent inefficient use of time and money. The growth hormone (GH)/insulin-like growth factor-1 (IGF-1) axis regulates growth based upon environmental factors such as feed intake in many teleost fish species. In order to increase the efficiency of aquaculture, the components of the GH/IGF-1 axis might be used as endocrine biomarkers to evaluate instantaneous growth rate. The goal of this study was to better understand the effects of feeding regimen on …

Two-Dimensional Blood Flow Velocity Estimation Using Ultrasound Speckle Pattern Dependence On Scan Direction And Velocity, Tiantian Xu

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Cardiovascular disease is the leading cause death in the United States. Although emergency surgery and medicine can be used for cardiovascular disease treatment, the survivors will suffer for it afterwards. Ultrasound blood flow measurement provides a noninvasive way for cardiovascular diseases diagnosis. In this dissertation, three algorithms for blood flow velocity measurements were investigated and optimized. Feature tracking has been previously proposed for vector velocity measurement. In Chapter 3, the optimal amplitude and time thresholds for feature extraction were investigated to minimize flow estimate variance while providing sufficient spatial and temporal coverage of flow area. A new method of lateral …

Dynamics Of Depression Storage During Sprinkler Irrigation And Precipitation Events, Michael B. Mckinney

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Surface depression storage (D_s) is the volume of precipitation excess which is stored by surface microrelief features of soils. The volume of water stored in surface depressions when precipitation rate exceeds infiltration rate reduces the amount of runoff generated. Because Ds is dependent on soil microrelief, land slope, and crop residue, tillage and management practices can have a considerable impact on the magnitude of this value.

When modeling irrigation systems and surface hydrology, depression storage is often treated as a static abstraction, meaning that maximum storage volume must be filled before runoff occurs. However, several researchers have documented …

Ethanol And Anaerobic Conditions Reversibly Inhibit Commercial Cellulase Activity In Thermophilic Simultaneous Saccharification And Fermentation (Tssf), Kara K. Podkaminer, William R. Kenealy, Christopher D. Herring, David A. Hogsett, Lee R. Lynd

Dartmouth Scholarship

A previously developed mathematical model of low solids thermophilic simultaneous saccharification and fermentation (tSSF) with Avicel was unable to predict performance at high solids using a commercial cellulase preparation (Spezyme CP) and the high ethanol yield Thermoanaerobacterium saccharolyticum strain ALK2. The observed hydrolysis proceeded more slowly than predicted at solids concentrations greater than 50 g/L Avicel. Factors responsible for this inaccuracy were investigated in this study.

Enhanced Hydrocarbon Biodegradation Using Bioaugmentation With Biowish™-Aqua Fog, Michael Robert Lehrer

Master's Theses

This study was done to determine the effectiveness of a commercially available bioaugmentation product, BiOWiSH^TM-Aqua FOG, for remediating petroleum-contaminated sandy soil. Biodegradation enhancement by BiOWiSH^TM-Aqua FOG was evaluated in laboratory microcosms by directly measuring total petroleum hydrocarbon (TPH) and indirectly using respirometry. Attempts were made to enrich hydrocarbon-degrading bacteria in BiOWiSH^TM-Aqua FOG, and the resulting enrichment cultures were screened using respirometry as well. Potential hydrocarbon-degrading bacteria in BiOWiSH^TM-Aqua FOG were isolated. Experiments were performed at bench-scale using microcosm bottles containing sand contaminated with either motor oil or No. 2 diesel fuel. The …

The Characterization Of Biofilm Attachment To Metal Interfaces: Effects Of Substratum Properties, Marcel D. Mendes

Master's Theses

Bacteria are among the most abundant microorganisms on earth, and can be found in essentially every environment. When a clean surface is exposed to media containing planktonic bacteria, the bacterial cells will attach to the surface and aggregate to form what is known as a biofilm. Biofilms have been shown to negatively affect many industries including medical, industrial, and food science applications. While biofilms have been well characterized from a microbiology perspective, there has been much less research from a materials science standpoint. It is hypothesized that the material properties of the substratum (such as the micro-structure) have a significant …