Food Science Commons^™

Native Cellular Architecture Of Treponema Denticola Revealed By Cryo-Electron Tomography, Jacques Izard, Chyong-Ere Hsieh, Ronald J. Limberger, Carmen A. Mannella, Michael Marko

Department of Food Science and Technology: Faculty Publications

Using cryo-electron tomography, we are developing a refined description of native cellular structures in the pathogenic spirochete Treponema denticola. Tightly organized bundles of periplasmic flagella were readily observed in intact plunge-frozen cells. The periplasmic space was measured in both wild-type and aflagellate strains, and found to widen by less than the diameter of flagella when the latter are present. This suggests that a structural change occurs in the peptidoglycan layer to accommodate the presence of the flagella. In dividing cells, the flagellar filaments were found to bridge the cytoplasmic cylinder constriction site. Cytoplasmic filaments, adjacent to the inner membrane, …

Processing Of The Phalloidin Proprotein By Prolyl Oligopeptidase From The Mushroom Conocybe Albipes, Hong Luo, Heather E. Hallen-Adams, Jonathan D. Walton

Department of Food Science and Technology: Faculty Publications

The peptide toxins of poisonous Amanita mushrooms are bicyclic octapeptides (amatoxins) or heptapeptides (phallotoxins). In Amanita bisporigera, α-amanitin and phallacidin are synthesized as 35- and 34-amino acid proproteins, respectively, in which the amino acid sequences found in the mature toxins are flanked by conserved amino acid sequences. The presence of invariant Pro residues immediately upstream of the toxin regions and as the last predicted amino acid in the toxin regions themselves suggests that a Pro-specific peptidase is responsible for the initial post-translational processing of the Amanita toxin proproteins. We purified an enzyme from the phalloidin-producing mushroom Conocybe albipes that …

Genomic Regions Conserved In Lineage Ii Escherichia Coli O157:H7 Strains, Marina Steele, Kim Ziebell, Yongxiang Zhang, Andrew K. Benson, Roger Johnson, Chad Laing, Eduardo Taboada, Victor Gannon

Department of Food Science and Technology: Faculty Publications

Populations of the food- and waterborne pathogen Escherichia coli O157:H7 are comprised of two major lineages. Recent studies have shown that specific genotypes within these lineages differ substantially in the frequencies with which they are associated with human clinical disease. While the nucleotide sequences of the genomes of lineage I strains E. coli O157 Sakai and EDL9333 have been determined, much less is known about the genomes of lineage II strains. In this study, suppression subtractive hybridization (SSH) was used to identify genomic features that define lineage II populations. Three SSH experiments were performed, yielding 1,085 genomic fragments consisting of …

Genomic Instability In Regions Adjacent To A Highly Conserved Pch Prophage In Escherichia Coli O157:H7 Generates Diversity In Expression Patterns Of The Lee Pathogenicity Island, Zhijie Yang, Jaehyoung Kim, Chaomei Zhang, Min Zhang, Joeseph Nietfeldt, Carolyn M. Southward, Michael G. Surette, Stephen D. Kachman, Andrew K. Benson

Department of Food Science and Technology: Faculty Publications

The LEE pathogenicity island has been acquired on multiple occasions within the different lineages of

enteropathogenic and enterohemorrhagic Escherichia coli. In each lineage, LEE expression is regulated by complex networks of pathways, including core pathways shared by all lineages and lineage-specific pathways. Within the O157:H7 lineage of enterohemorrhagic E. coli, strain-to-strain variation in LEE expression has been observed, implying that expression patterns can diversify even within highly related subpopulations. Using comparative genomics of E. coli O157:H7 subpopulations, we have identified one source of strain-level variation affecting LEE expression. The variation occurs in prophage-dense regions of the genome that …

Pyramidobacter Piscolens Gen. Nov., Sp. Nov., A Member Of The Phylum ‘Synergistetes’ Isolated From The Human Oral Cavity, Julia Downes, Sonia R. Vartoukian, Floyd E. Dewhirst, Jacques Izard, Tsute Chen, Wen-Han Yu, Iain C. Sutcliffe, William G. Wade

Department of Food Science and Technology: Faculty Publications

Four strains of anaerobic, gram-negative bacilli isolated from the human oral cavity were subjected to a comprehensive range of phenotypic and genotypic tests and were found to comprise a homogeneous group distinct from any species with validly published names. 16S rRNA and 23S rRNA gene sequence analyses and DNA–DNA reassociation data revealed that the strains constituted a novel group within the phylum ‘Synergistetes’ and were most closely related to Jonquetella anthropi. Two libraries of randomly cloned DNA were prepared from strain W5455T and were sequenced to provide a genome survey as a resource for metagenomic studies. A new genus …

Cryo-Electron Tomography Elucidates The Molecular Architecture Of Treponema Pallidum, The Syphilis Spirochete, Jacques Izard, Christian Renken, Chyong-Ere Hsieh, Daniel C. Desrosiers, Star Dunham-Ems, Carson La Vake, Linda L. Gebhardt, Ronald J. Limberger, David L. Cox, Michael Marko, Justin D. Radolf

Department of Food Science and Technology: Faculty Publications

Cryo-electron tomography (CET) was used to examine the native cellular organization of Treponema pallidum, the syphilis spirochete. T. pallidum cells appeared to form flat waves, did not contain an outer coat and, except for bulges over the basal bodies and widening in the vicinity of flagellar filaments, displayed a uniform periplasmic space. Although the outer membrane (OM) generally was smooth in contour, OM extrusions and blebs frequently were observed, highlighting the structure’s fluidity and lack of attachment to underlying periplasmic constituents. Cytoplasmic filaments converged from their attachment points opposite the basal bodies to form arrays that ran roughly …

Triacylglyceride Metabolism By Fusarium Graminearum During Colonization And Sexual Development On Wheat, John C. Guenther, Heather E. Hallen-Adams, Heike Bücking, Yair Shachar-Hill, Frances Trail

Department of Food Science and Technology: Faculty Publications

Fusarium graminearum, a devastating pathogen of small grains, overwinters on crop residues and produces ephemeral perithecia. Accumulation of lipids in overwintering hyphae would provide reserves for overwinter survival and perithecium development. Fatty acid composition of cultures during perithecium development indicated a drop in neutral lipid levels during development but little change in fatty acid composition across stages. Microscopic examination of cultures early in sexual development revealed hyphal cells engorged with lipid bodies. In comparison, vegetative hyphae contained few lipid bodies. Microarray analysis was performed on wheat stems at stages of colonization through perithecium development. Gene expression analysis during stages of …

Diet-Induced Metabolic Improvements In A Hamster Model Of Hypercholesterolemia Are Strongly Linked To Alterations Of The Gut Microbiota, Inés Martínez, Chaomei Zhang, Ryan Legge, Andrew K. Benson, Timothy P. Carr, Etsuko N. Moriyama, Jens Walter

Department of Food Science and Technology: Faculty Publications

The mammalian gastrointestinal microbiota exerts a strong influence on host lipid and cholesterol metabolism. In this study, we have characterized the interplay among diet, gut microbial ecology, and cholesterol metabolism in a hamster model of hypercholesterolemia. Previous work in this model had shown that grain sorghum lipid extract (GSL) included in the diet significantly improved the high-density lipoprotein (HDL)/ non-HDL cholesterol equilibrium (T. P. Carr, C. L. Weller, V. L. Schlegel, S. L. Cuppett, D. M. Guderian, Jr., and K. R. Johnson, J. Nutr. 135:2236-2240, 2005). Molecular analysis of the hamsters’ fecal bacterial populations by pyrosequencing of 16S rRNA tags, …

Clinical Relevance Of Sensitization To Lupine In Peanut-Sensitized Adults, K. A. B. M. Peeters, Stef J. Koppelman, A. H. Penninks, A. Lebens, C. A. F. M. Bruijnzeel-Koomen, S. L. Hefle, S. L. Taylor, E. Van Hoffen, A. C. Knulst

Department of Food Science and Technology: Faculty Publications

Background: The use of lupine in food has been increasing during the last decade and allergic reactions to lupine have been reported, especially in peanut-allergic patients. The frequency and the degree of cross-reactivity to other legumes are not known. The aim of the study was to investigate the frequency of sensitization to lupine, and in addition to pea and soy, and its clinical relevance, in peanutsensitized patients. Furthermore, to determine the eliciting dose (ED) for lupine using double-blind placebo-controlled food challenges (DBPCFC).

Methods: Thirty-nine unselected peanut-sensitized patients were evaluated by skin prick tests (SPT) and ImmunoCAP to lupine, pea, and …

Characterization Of Dna Sequences That Confer Complement Resistance In Leishmania Chagasi, Rebecca R. Dahlin-Laborde, Eric J. Scolaro, Nathan M. Romine, Amanda Ramer-Tait, Soi Meng Lei, Jeffrey K. Beetham

Department of Food Science and Technology: Faculty Publications

Serial passage of axenically cultured Leishmania chagasi promastigotes results in a progressive diminution in resistance to complement-mediated lysis (CML), whereas high CML resistance is seen in infectious metacyclic promastigotes from the sandfly vector as well as metacyclic-like promastigotes within low-passage cultures at stationary growth phase. As we previously reported, in a screen seeking to identify novel genes involved in CML resistance: (1) a genomic cosmid library derived from DNA of CML-resistant L. chagasi promastigotes was transfected into highpassage (constitutively CML-sensitive) L. chagasi promastigotes; (2) transformants were screened for acquisition of CML-resistance; (3) multiple cosmid-transfectants exhibited partial CML resistance; and (4) …

The Food Processing Center News, Fall 2008

Department of Food Science and Technology: Public Access Records

CONTENTS:
FDST Students Star at IFT
Membrane Filtration Opportunities for the Food Industry
Food Safety Conference a Shared Success
A Message From Dr. Flores
Dr. Hanna “Most Cited” Author of 10 Years
Alumnus Bob Bidrowski
MS Graduate Carolina Leguizamon
Graduates of the B.S. Program
Graduates of the M.S. Program
Graduates of the Ph.D. Program
UNL AWARDS
Undergraduate Interns in Home Country
Accomplishments
Graduate Student Spotlight: Tim Anderson
New M.S. Students
New Ph.D. Students
From Culture-based Methods to DNA Sequencing of Entire Ecostyems: A Major Shift in the Paradigm of Diagnostic Microbiology
Faculty/Staff
Professor of Mucosal Immunology Joins FDST
Visiting Faculty …

Disseminated Leishmania Infantum Infection In Two Sibling Foxhounds Due To Possible Vertical Transmission, Katherine N. Gibson-Corley, Jesse M. Hostetter, Shannon J. Hostetter, Kathleen Mullin, Amanda Ramer-Tait, Paola M. Boggiatto, Christine A. Petersen

Department of Food Science and Technology: Faculty Publications

Two sibling foxhounds born to a Leishmania seropositive bitch were presented after testing seropositive for Leishmania. Leishmania infantum infection was detected via histopathology, culture, and quantitative polymerase chain reaction (q-PCR). This is the first report of natural infection with Leishmania infantum with the possibility for vertical transmission in North America.

Infection disséminée à Leishmania infantum chez deux chiots Fox hound d’une même portée reliée possiblement à une transmission verticale. Deux chiots Fox hound d’une même portée nés d’une mère séropositive à Leishmania ont été présentés après un contrôle sérologique positif. Une infection à Leishmania infantum a été détectée par …

454 Applications: Just How Creative Can You Be?

Core for Applied Genomics and Ecology (CAGE)

CONTENTS:
Deep Sequencing and Variant analysis
Microbial Population Structures in the Deep Marine Biosphere
Direct Selection of Human Genomic Loci by Microarray Hybridization
Whole Genome Sequencing and Resequencing
Transcriptome mapping
Specialized methods for cDNA sequencing
Library Normalization by dsDNA nuclease digestion

Bioinformatics And Data Analysis

Core for Applied Genomics and Ecology (CAGE)

CONTENTS:
Run-time applications
Post-run applications
Image processing
Signal processing
de novo Assembly
Reference Mapper
Variant analysis

Next Generation Dna Sequencing And The Birth Of A Golden Era For Microbial Ecology

Core for Applied Genomics and Ecology (CAGE)

In 2005, a breakthrough technology was Announced that provided a quantum leap In DNA sequencing capacity.

This technology differed from the Sanger method In many ways:
1. Eliminates cloning—completely circumvents cloning bias
2. Uses bead technology—DNA templates are attached to sepharose beads
3. Relies on pyrosequencing chemistry—synthesis is sequential not partial
4. Parallelizes the sequencing process—hundreds of thousands of beads can be sequenced in parallel

The bottom line: it makes production-scale sequencing available to the common man.

Guide To Floor Malting Of Sorghum And Millets, John R.N. Taylor

INTSORMIL Scientific Publications

Malt (dried, sprouted cereal grain) is the major ingredient in most beers and in certain hot and cold beverages. It is also a useful ingredient in some cereal food products such as bread and infant porridges. In terms of nutrients, malt contains mainly complex carbohydrates (starch and dietary fiber), but also protein of reasonable quality and availability, B vitamins and minerals. Malt is a source of hydrolytic enzymes, especially amylases. In brewing, the malt amylases produce the sugars which the yeast ferments to alcohol and carbon dioxide The amylases also increase the sweetness and improve the texture of food products …

Food Science & Technology Alumni News, Spring 2008

Department of Food Science and Technology: Public Access Records

CONTENTS:
A message from the Department Head . . .
Graduates of the B.S. Program
Graduates of the M.S. Program
Graduates of the Ph.D. Program
Steve Beckman, Baccalaureate and Future Ph.D.
Help Us Find New Students
Recent Graduate Wee Chin Low
Dr. Taylor at Work in the Netherlands
New B.S. Students
New M.S. Graduate Students
Visiting Faculty and New Opportunities from Costa Rica
Busy Autumn for the Food Science Club
Graduate Student Spotlight: Inés Martínez
FSC Roster
Undergraduate Spotlight: Melanie Downs
New and Improved Sensory Analysis Lab
Selected Grants
New Faces
Departures
Visiting Faculty
Food Science Alumna Wins Folsom Award …

Repression Of Proinflammatory Gene Expression By Lipid Extract Of Nostoc Commune Var Sphaeroides Kützing, A Blue-Green Alga, Via Inhibition Of Nuclear Factor-Κb In Raw 264.7 Macrophages, Young-Ki Park, Heather E. Rasmussen, Sarah J. Ehlers, Kara R. Blobaum, Fan Lu, Vicki L. Schlegel, Timothy P. Carr, Ji-Young Lee

Department of Food Science and Technology: Faculty Publications

We investigated whether lipid extract from a blue-green alga, N. commune, modulates proinflammatory gene expression in RAW 264.7 macrophages. The cells were incubated with N. commune lipid extract (0–100 μg/mL) and subsequently activated by LPS (100 ng/mL). Quantitative real-time PCR analysis showed that mRNA abundance of proinflammatory mediators, including TNF-α, COX-2, IL-1β, IL-6, and iNOS, was significantly reduced by N. commune lipid extract in a dose-dependent manner. Secretion of TNF-α and IL-1β into cell culture medium was also significantly decreased by N. commune lipid extract. Thin-layer chromatography-densitometry analysis showed that N. commune …

Modeling Residence Time Distribution In A Twin-Screw Extruder As A Series Of Ideal Steady-State Flow Reactors, Ajay Kumar, Girish M. Ganjyal, David D. Jones, Milford Hanna

Department of Food Science and Technology: Faculty Publications

Knowledge about and control of residence time distribution (RTD) is critical for determining optimal conditions in an extrusion process. In this paper, previously proposed models for RTD have been summarized and compared with the experimental data. The best-fit model was found to be a plug flow in series with a finite number of constantly stirred tank reactors having dead volume fractions. Parameters of the best-fit model were predicted from input variables (moisture content, screw speed, nozzle diameter and barrel temperature). Predicted RTD from the input variables had a r ²> 0.96. Experiments were conducted using a full factorial design with …

Unl Announces Opening Of Core For Applied Genomics And Ecology (Cage), Andy Benson

Core for Applied Genomics and Ecology (CAGE)

The UNL Core for Applied Genomics and Ecology (CAGE) announces that it is now offering a new suite of services to UNL investigators and outside entities. Formerly known as the UNL Printed Microarray Core Facility, CAGE now offers Next Gen sequencing on its newly installed Roche-454 GS FLX. In support of the UNL Gut Function Initiative, CAGE specializes in application of the GS-FLX platform for analysis of complex microbial communities by massively parallel sequencing of 16S rRNA amplicons. CAGE also has expertise in shotgun sequencing applications on the instrument, including whole genome sequencing and analysis of BACs and metagenome libraries. …

Next Gen Sequencing: An Alternative To Culture-Based Microbiological Testing

Core for Applied Genomics and Ecology (CAGE)

Next Gen DNA Sequencing Enables You...
• to analyze microbial communities and ecosystems in food products
• perform food safety testing
• address spoilage and other non-safety issues
• optimize food processing
• create databases of “good” microbial profiles associated with target product characteristics

Quantitative Trait Locus Mapping For Seed Mineral Concentrations In Two Arabidopsis Thaliana Recombinant Inbred Populations, Brian M. Waters, Michael A. Grusak

Department of Agronomy and Horticulture: Faculty Publications

Biofortification of foods, achieved by increasing the concentrations of minerals such as iron (Fe) and zinc (Zn), is a goal of plant scientists. Understanding genes that influence seed mineral concentration in a model plant such as Arabidopsis could help in the development of nutritionally enhanced crop cultivars. Quantitative trait locus (QTL) mapping for seed concentrations of calcium (Ca), copper (Cu), Fe, potassium (K), magnesium (Mg), manganese (Mn), phosphorus (P), sulfur (S), and Zn was performed using two recombinant inbred line (RIL) populations, Columbia (Col) × Landsberg erecta (Ler) and Cape Verde Islands (Cvi) × Ler, grown …

Comparison Of Amylose Determination Methods And The Development Of A Dual Wavelength Iodine Binding Technique, Thianming Zhu, David S. Jackson, Randy L. Wehling, Bhima Geera

Department of Food Science and Technology: Faculty Publications

It has long been recognized that limitations exist in the analytical methodology for amylose determination. This study was conducted to evaluate various amylose determination methods. Purified amylose and amylopectin fractions were obtained from com, rice, wheat, and potato and then mixed in proportion to make 10, 20, 30, 50, and 80% amylose content starch samples for each source. These samples, considered amylose standards, were analyzed using differential scanning calorimetry (DSC), high-performance size-exclusion chromatography (HPSEC), and iodine binding procedures to generate standard curves for each of the methods. A single DSC standard equation for cereal starches was developed. The standard curve …

Genotypic Characterization And Prevalence Of Virulence Factors Among Canadian Escherichia Coli O157:H7 Strains, Kim Ziebell, Marina Steele, Yongxiang Zhang, Andrew K. Benson, Eduardo N. Taboada, Chad Laing, Scott Mcewen, Bruce Ciebin, Roger Johnson, Victor Gannon

Department of Food Science and Technology: Faculty Publications

In this study, the association between genotypic and selected phenotypic characteristics was examined in a collection of Canadian Escherichia coli O157:H7 strains isolated from humans and cattle in the provinces of Alberta, Ontario, Saskatchewan, and Quebec. In a subset of 69 strains selected on the basis of specific phage types (PTs), a strong correlation between the lineage-specific polymorphism assay (LSPA6) genotype and PT was observed with all strains of PTs 4, 14, 21, 31, 33, and 87 belonging to the LSPA6 lineage I (LSPA6-LI) genotype, while those of PTs 23, 45, 67, and 74 belonged to LSPA6 lineage II (LSPA6-LII) …

The L-Type Calcium Ion Channel Cch1 Affects Ascospore Discharge And Mycelial Growth In The Filamentous Fungus Gibberella Zeae (Anamorph Fusarium Graminearum), Heather E. Hallen-Adams, Frances Trail

Department of Food Science and Technology: Faculty Publications

Cch1, a putative voltage-gated calcium ion channel, was investigated for its role in ascus development in Gibberella zeae. Gene replacement mutants of CCH1 were generated and found to have asci which did not forcibly discharge spores, although morphologically ascus and ascospore development in the majority of asci appeared normal. Additionally, mycelial growth was significantly slower, and sexual development was slightly delayed in the mutant; mutant mycelia showed a distinctive fluffy morphology, and no cirrhi were produced. Wheat infected with Δcch1 mutants developed symptoms comparable to wheat infected with the wild type; however, the mutants showed a reduced ability …

Allergenicity Assessment Of Genetically Modified Crops—What Makes Sense?, Richard E. Goodman, Stefan Vieths, Hugh A. Sampson, David Hill, Motohiro Ebisawa, Ronald Van Ree

Department of Food Science and Technology: Faculty Publications

GM crops have great potential to improve food quality, increase harvest yields and decrease dependency on certain chemical pesticides. Before entering the market their safety needs to be scrutinized. This includes a detailed analysis of allergenic risks, as the safety of allergic consumers has high priority. However, not all tests currently being applied to assessing allergenicity have a sound scientific basis. Recent events with transgenic crops reveal the fallacy of applying such tests to GM crops.

Use Of Near-Infrared Spectroscopy For Qualitative And Quantitative Analyses Of Grains And Cereal Products, Panjama Cheewapramong

Department of Food Science and Technology: Dissertations, Theses, and Student Research

The purpose of the first part of the study was to develop a simplified near-infrared reflectance (NIR) spectroscopy method for detecting insect larvae in individual wheat kernels. Discriminant analysis, based on Mahalanobis distances calculated from log 1/R data at only four discrete wavelengths, yielded better results for classification of sound and insect infested wheat kernels than principal component analysis (PCA) using the spectral region from 1100 to 1900 nm. This simplified technique was then used to detect 3- and 4-week-old larvae of granary and maize weevils in wheat kernels. A model developed from a calibration set containing sound kernels and …

Food Science & Technology Alumni News, Fall 2007

Department of Food Science and Technology: Public Access Records

CONTENTS:
A message from the Department Head . . .
Graduates of the B.S. Program
Graduates of the M.S. Program
New M.S. Graduate Students
New Ph.D. Graduate Students
Graduate Follow-up
Food Science Club
Sophomore Food Science Major Wins Candy Scholarship
New Faces
Departures
Visiting Faculty
Let us Know how you’re doing!
Hyperspectral Imaging to Predict Beef Tenderness
Food Technology for Companion Animals: Research Grants
2007: The 90th Anniversary of the Dairy Store
Products Available at the Dairy Store
IICA Visits UNL
Fortenberry Holds Educational Conference on Local Foods
Laboratory Services
Meet the Faculty
Conferences and Workshops

Functional Analysis Of The Fructooligosaccharide Utilization Operon In Lactobacillus Paracasei 1195, Yong Jun Goh, Jong-Hwa Lee, Robert W. Hutkins

Department of Food Science and Technology: Faculty Publications

The fosABCDXE operon encodes components of a putative fructose/mannose phosphoenolpyruvate-dependent phosphotransferase system (PTS) and a β- fructosidase precursor (FosE) that are involved in the fructooligosaccharide (FOS) utilization pathway of Lactobacillus paracasei 1195. The presence of an N-terminal signal peptide sequence and a LPQAG cell wall anchor motif at the C-terminal region of the deduced FosE precursor amino acid sequence predicted that the enzyme is cell wall-associated, indicating that FOS may be hydrolyzed extracellularly. In this study, cell fractionation experiments demonstrated that the FOS hydrolysis activity was contained exclusively in the cell wall extract of L. paracasei previously grown on FOS. …

Food Science & Technology Alumni News, Spring 2007

Department of Food Science and Technology: Public Access Records

CONTENTS:
A message from the Department Head...
FPC Workshop Overview
Whole Foods Conference News¬
Graduates of the B.S. Program
Graduates of the M.S. Program
Graduates of the Ph.D. Program
New M.S. Graduate Students
Help Us Find New Students
Let us Know where you are now!
Development of Functional Foods and Nutraceuticals at the University of Nebraska-Lincoln
Food Science Extension Program
2006 Japan Trade Mission
New Staff
New Faculty
2007: The 90th Anniversary of the Dairy Store
Products Available at the Dairy Store
Research Grants
Printed Microarray Core Facility
New Aflatoxin Test at FPC Laboratory Servic¬es
Conferences and Workshops