Mountain Scholar :: Browsing by Author "Prenni, Jessica, committee member"

Browsing by Author "Prenni, Jessica, committee member"

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Open Access
Addressing the threat of frost damage on peach floral buds through large-scale cold hardiness phenotyping, dynamic weather modeling and non-targeted metabolomic and proteomic analysis
(Colorado State University. Libraries, 2023) Sterle, David, author; Minas, Ioannis, advisor; Sharp, Julia, committee member; Prenni, Jessica, committee member; Caspari, Horst, committee member
Cold damage to reproductive tissues is the greatest threat to the profitability of peach (Prunus persica) growers worldwide. Cold hardiness is the extent to which peach floral buds super-freeze without suffering lethal damage. Although no changes are visible externally to floral buds for much of the dormant season, cold hardiness fluctuates as they acclimate, deacclimate and respond to abiotic stressors such as temperature or drought. A greater understanding of the mechanisms involved in these fluctuations involves accurate and frequent measurement of the extent to which cold hardiness is changing, and the ambient weather factors influencing the changes, at different stages of the dormant season. Warmer or more erratic temperature changes during the dormant season threatens peach floral buds to more frequently receive frost damage if cold hardiness becomes misaligned with the timing of lethally cold weather events. Statistical analysis of the trends and forces impacting the cold hardiness of floral buds can help identify significant patterns. These patterns can be used to better understand the physiological mechanisms affecting cold hardiness changes, and they can be used to help predict the impact of weather conditions on cold hardiness. In addition to their use in a practical sense by growers to aid in frost management decisions, accurate cold hardiness prediction models can be used to estimate what effects foreseeable climate effects can have on the outlook of future peach production. Metabolic changes are known to occur in dormant plants, although the effects of the metabolome in peaches on cold hardiness are unknown. Changes associated with cold hardiness likely follow several trends. One such trend is the fluctuations of metabolic abundances across the season, which are more associated with the endodormancy, and ecodormancy phases and the prebloom phase. These trends likely take place every dormant season as buds undergo a steady process of acclimating and deacclimating. Another trend is the response floral buds exhibit in response to acute cold events, in order to rapidly increase cold hardiness. The study of this response necessitates the monitoring of cold hardiness as well as the metabolic shift to the weather event. The response can be further elucidated by comparing cold hardiness and metabolic changes between genotypes that have different cold hardiness phenotypes. By exploring changes a cold hardy genotype undergoes, geneticists may be able to target certain metabolic expressions that may increase the frost tolerance of future cultivars. Since frost damage can be so destructive to peach production, it is necessary to understand the risks to the peach industry moving forward surrounding climate change, and it is also necessary to understand the extent to which frost tolerance can be improved in future cultivars. This study uses a multifaceted approach to cold hardiness which involves improved and large-scale cold hardiness phenotyping using differential thermal analysis, dynamic weather prediction models and associated metabolic regulation understanding.
Open Access
An evaluation of yield and quality characteristics for vegetable crops grown under organic management in Fort Collins, Colorado
(Colorado State University. Libraries, 2020) Mason, Tyler, author; Uchanski, Mark, advisor; Bartolo, Michael, committee member; Johnson, Sarah, committee member; Prenni, Jessica, committee member
To view the abstract, please see the full text of the document.
Open Access
Assessment of novel causes and investigation into the gut microbiome in cats with chronic kidney disease
(Colorado State University. Libraries, 2020) Summers, Stacie, author; Lappin, Michael, advisor; Quimby, Jessica, committee member; Dow, Steve, committee member; Prenni, Jessica, committee member
To view the abstract, please see the full text of the document.
Open Access
Assessment of rapid evaporative ionization mass spectrometry (REIMS) to characterize beef quality and the impact of oven temperature and relative humidity on beef
(Colorado State University. Libraries, 2018) Gredell, Devin, author; Woerner, Dale, advisor; Belk, Keith, committee member; Engle, Terry, committee member; Prenni, Jessica, committee member; Heuberger, Adam, committee member
The objective of experiment 1 was to evaluate the ability of rapid evaporative ionization mass spectrometry (REIMS) to predict beef eating quality characteristics. Striploin sections (5 cm in thickness; N = 292) from 7 beef carcass types (Select, Low Choice, Top Choice, Prime, Dark Cutter, Grass-fed, and Wagyu) were collected to achieve variation in fat content, sensory attributes, tenderness, and production background. Sections were aged for 14 d, fabricated into 2.54 cm thick steaks, and frozen until analysis. Trained descriptive panel rated tenderness, flavor, and juiciness attributes for sensory prediction models. Slice shear force (SSF) and Warner-Bratzler shear force (WBS) values were measured to predict tenderness classifications. A molecular fingerprint of each sample was collected via REIMS to build prediction models. Models were built using 80% of samples that were selected randomly for this purpose and tested for prediction accuracy using the remaining 20%. Partial least squares (PLS) discriminant analysis was used as a dimension reduction technique before building a linear discriminant analysis (LDA) model for classification. When Select and Low Choice samples, as well as Top Choice and Prime samples, were combined, balanced prediction accuracy reached 83.8%. Slice shear force and WBS tenderness classifications (tough vs tender) were predicted with 75.0% and 70.2% accuracy, respectively. Sensory models were built to assign samples into positive and negative classifications based on either all sensory attributes (i.e., tenderness, juiciness, and flavor) or only flavor attributes. Overall sensory class was predicted with 75.4% accuracy and flavor class with 70.3%. With future fine-tuning, these data suggest that REIMS produces a metabolic fingerprint to provide a method to meaningfully predict numerous beef quality attributes in an on-line application. The objective of the second study was to evaluate the roles of cooking rate and relative humidity on sensory development of beef strip steaks. Thirty USDA Choice beef strip loins were collected from a commercial packing facility. Each strip loin was cut into steaks and randomly assigned to 1 of 6 cooking methods utilizing 2 oven temperatures (80°C and 204°C) and 3 levels of relative humidity [zero (ZH), mid (MH), and high (HH)]. Cooked steaks were used to evaluate internal and external color, Warner-Bratzler and slice shear force, total collagen content, protein denaturation, and trained sensory ratings. Relative humidity greatly reduced cooking rate, especially at 80°C. Steaks cooked at 80°C-ZH had the greatest (P < 0.01) cook loss of all treatments, and cook loss was not affected (P > 0.05). Steaks cooked at 80C-ZH appeared the most (P < 0.01) well-done and had the darkest (P > 0.01) surface color. Total collagen was greatest (P < 0.01) in steaks cooked with ZH, regardless of oven temperature. Myosin denaturation was not affected (P > 0.05) by treatment. Increased (P = 0.02) sarcoplasmic protein denaturation was observed with ZH and MH, while increased (P = 0.02) actin denaturation was observed only with ZH. Oven temperature did not influence (P > 0.05) protein denaturation. Trained panelists rated steaks most tender (P < 0.01) when cooked at 80°C and with ZH and MH. Humidity did not affect (P > 0.05) juiciness at 204°C; however, MH and HH produced a juicier (P < 0.01) steak when cooked at 80°C. Humidity hindered (P < 0.01) the development of beefy/brothy and brown/grilled flavors but increased (P = 0.01) metallic/bloody intensity. Lower oven temperatures and moderate levels of humidity could be utilized to maximize tenderness, while minimally affecting flavor development.
Open Access
Beet curly top virus-beet leafhopper dynamics in hemp in Colorado
(Colorado State University. Libraries, 2021) Chiginsky, Judith, author; Nachappa, Punya, advisor; Prenni, Jessica, committee member; Cranshaw, Whitney, committee member
Hemp (Cannabis sativa L.) production within North America has dramatically increased in recent years following legislative changes in the 2014 and 2018 Farm Bills that allowed legal paths for its production. However, due to previous restrictions on this crop it has been understudied in the U.S. since its production declined, and ultimately was eliminated. Restrictive laws largely prevented any research regarding management of this crop. Among the understudied issues were those associated with disease identification and management. One newly described disease of the crop in Colorado beet curly top virus (BCTV). This viral pathogen is transmitted by an insect vector, the beet leafhopper. To better understand the diversity and prevalence of BCTV strains infecting hemp in Colorado, beet curly top virus (BCTV) was detected at high incidence (81%) in leaf samples from 12 counties in 2019. Two different strains of BCTV, BCTV-Worland and BCTV-Colorado were found present in single or mixed infection in hemp leaf samples. Phylogenetic analysis revealed BCTV sequences from hemp formed a distinct group along with BCTV-Colorado and BCTV-Worland strains. To determine other potential viral and viroid pathogens in hemp, shotgun metagenomic analysis was performed. Virome analysis revealed the presence of seven viruses and one viroid. Of these, cannabis cryptic virus, cannabis sativa mitovirus, citrus yellow vein associated, opuntia-like virus and hop latent viroid sequences that had high sequence similarity with their corresponding sequences in GenBank. In contrast, tobacco streak virus sequence was highly variable compared to sequences in GenBank suggesting a new genotype of this virus. The data presented here has important implications for the epidemiology and management of the various diseases of hemp and will lead to the development of integrated pest management strategies designed to interrupt transmission cycles and facilitate efficient crop production. Beet leafhopper abundance was monitored throughout the hemp season to understand timing of emergence and flight patterns in the north and western regions of Colorado as well as identify timing of population peaks. Virus incidence in hemp and weed species were assessed using PCR analysis. Beet curly top virus was detected earlier in western field sites of Colorado before being detected in northern survey sites. Of the 41 different weed species surveyed, the weeds that most often tested positive for BCTV, contributing to transmission prevalence were Lactuca serriola (prickly lettuce), Taraxacum officinale (dandelion), and Cichorium intybus (chicory). Life history assays were conducted using viruliferous and non-viruliferous beet leafhoppers in both sugar beet and hemp plants to understand if there were any fitness advantages or costs associated with being a carrier of the virus. Viruliferous beet leafhoppers reared on sugar beet produced more offspring than non-viruliferous treatments. There was no difference between viruliferous, and non-viruliferous beet leafhoppers reared on hemp, suggesting that these virus mediated differences in life history are induced in host plant interactions with the vector. However, beet leafhoppers were able to survive 7-day periods and successfully oviposit and develop on hemp. Understanding migration timing and patterns will result in a more thorough understanding of the pest ecology of the beet leafhopper, which will lead to targeted control strategies to incorporate into integrated pest management tactics to interrupt BCTV transmission cycles, in turn improving yield and farming efficiency.
Open Access
Bridging the gap between biofortification and consumption: evaluating sorghum grain carotenoid degradation
(Colorado State University. Libraries, 2023) Lepard, Ariel, author; Rhodes, Davina, advisor; Van Buiten, Charlene, committee member; Prenni, Jessica, committee member; Scanlin, Laurie, committee member
Sorghum (Sorghum bicolor) is a major staple cereal crop consumed in sub-Saharan Africa and Southeast Asia, where some of the highest rates of vitamin A deficiency (VAD) are found. As with most cereals, sorghum has low concentrations of provitamin A carotenoids, which are converted to vitamin A in the body. Biofortification provides an opportunity to address VAD through the nutritional improvement of sorghum grain using a non-transgenic breeding approach to increase grain carotenoids. Though vitamin A biofortification in sorghum is possible, it is unknown if breeding for high carotenoids in the grain negatively affects carotenoid pathway functions in other tissues. Additionally, it is unknown if degradation during postharvest processing occurs to a significant degree in biofortified grain. To establish how breeding for high carotenoids in the grain affects the carotenoid pathway in other plant tissues, expression of ten genes in the carotenoid precursor, biosynthesis, or degradation pathways were evaluated in the grain, leaf, and root tissues. A correlation in the gene expression within the plant tissue, but not between the plant tissues, was found for most genes, which suggests that several of the carotenoid precursor, biosynthesis, and degradation genes are controlled by tissue-specific regulation. Correlation of carotenoid concentrations and gene expression was also found to be tissue specific, which further suggests tissue-specific regulation. The selection of genes with tissue-specific regulation for marker-assisted breeding reduces the chances of grain biofortification negatively affecting other tissues. Once carotenoids have been increased in the grain, it must be noted that vitamin A is not stable in most storage, processing, and cooking environments due to oxidative stress from light, heat, and oxygen. The degradation of the nutritional quality through post-harvest processing was evaluated by sampling carotenoid grain throughout harvest, drying, storage, processing, and cooking. Individual processing steps did not cause significant degradation but added up to significant degradation by the final cooking step, with ~39% of β-carotene loss. No significant difference between the loss in the different storage temperatures or cooking styles was seen. An increase in the target value from 4 μg β-carotene/g of sorghum to 5.6 μg/g will be needed to account for processing loss in order to provide 50% of the estimated average requirement (EAR) of vitamin A. Overall, both the information on tissue specific gene expression, and post-harvest degradation will further advance the development of carotenoid biofortified sorghum lines.
Open Access
Capabilities of rapid evaporative ionization mass spectrometry to predict lamb flavor and overview of feeding genetically modified grain to livestock
(Colorado State University. Libraries, 2019) Gifford, Cody Lynn, author; Woerner, Dale, advisor; Belk, Keith, committee member; Engle, Terry, committee member; Prenni, Jessica, committee member; Heuberger, Adam, committee member
The objective of experiment 1 was to evaluate the ability of rapid evaporative ionization mass spectrometry (REIMS) to predict characteristics of cooked sheep meat flavor using metabolomic data from raw samples. Boneless leg samples were obtained from 150 carcasses of sheep representing three age classifications (n=50 per age classification), at three USDA inspected harvest facilities located in Colorado and California, between October 2017 to June 2018. A trained descriptive panel rated seven flavor attributes. Metabolomic data from fat, lean and ground patties from legs of sheep carcasses were captured through the REIMS platform. Principal component analysis factor scores were used in hierarchical cluster analysis to assess two-level and three-level sensory clusters. Partial least squares (PLS) was used to reduce dimensionality of data before the linear discriminant analysis (LDA) model was built. Eighty percent of the samples were randomly selected to train models and the remaining 20% were used to test prediction accuracy. Mutton carcasses were identified with 88.9% sensitivity and 80.0% precision using external fat of the leg and with 100% sensitivity and 90.9% precision using ground patties. Yearling carcasses were identified with 85.7% precision using lean and lambs were predicted with 70% precision using lean and fat tissue. Greater than 80% accuracy (overall and balanced), sensitivity and precision was achieved in models using lean and ground patties to identify production background (whether the live animal that produced the lean or ground patties was grain-finished or grass-finished). Prediction accuracies of age classification, production background and two-level flavor performance categories were 68% or higher with various machine learning algorithms coupled with data dimension reduction approaches. Further work is warranted to validate use of this technology in an on-line production setting and additional datasets could be used to further refine or create additional prediction models with better understanding of data processing characteristics. The review was conducted to assess the scientific literature for evidence of altered health effects in livestock species that have been fed genetically modified grain and any health effects discussed in reference to human consumption of meat products from those animals. Public concern still exists for feeding genetically modified (GM) or genetically engineered (GE) corn to animals that produce animal protein foods. In the U.S., 90% of all corn acres planted in 2013 were from single herbicide or insect resistance GE corn varieties. Regulation of GE crops is mandatory in the U.S. and consists of review and approval by three different Federal agencies. Substantial equivalence is a principle used in evaluating the safety of GE crops to establish that transgenic (GE or GM) varieties are nutritionally similar and as safe as non-transgenic crops. Animal feeding trials can provide further information to establish the safety of GE crops for human and animal consumption. No publications were found that had reported human metabolic effects from consuming beef cattle fed genetically modified grains. No consistent conclusions have been made that feeding GE corn to mice or rats, beef or dairy cattle, swine, or poultry causes any adverse effects to health. Parameters regarding sample size, diet treatments and specified controls exist to guide researchers in designing animal feeding trials with GE crops, but many criticisms of the scientific literature still exist. Additionally, published feeding trials conducted with transgenic corn grain and silage in beef cattle are limited.
Open Access
Characterization of protein-polyphenol interactions between novel plant proteins (pea and hemp) and blueberry polyphenols with respect to polyphenol binding and delivery
(Colorado State University. Libraries, 2022) Chima, Bianca, author; Van Buiten, Charlene, advisor; Johnson, Sarah, committee member; Prenni, Jessica, committee member
Despite the numerous health benefits associated with polyphenols, dietary intake of this class of compounds is low in the United States due to low intake of fruits and vegetables. It has been shown that dairy foods (i.e. milk, yogurt) increase polyphenol bioavailability due to polyphenols interacting with whey protein, enhancing polyphenol stability and uptake throughout digestion. However, increasing concerns for sustainability and health have introduced a variety of novel plant-based proteins as dairy alternatives. This study aimed to investigate the abilities of edible pea and hemp protein isolates to form complexes with blueberry polyphenol extract (BPE) and characterize the physical and biological functionalities of these complexes compared to whey proteins. Protein/polyphenol solutions were analyzed using UV-Vis spectroscopy to determine if complexation occurred. Secondary structures and binding affinities were analyzed by far-UV CD Spectroscopy and fluorimetry, respectively. In vitro digestion was performed to determine whether the protein profile changed in the presence of BPE via SDS-PAGE and determination of free amino acids using the ninhydrin method. Protein isolates from pea and hemp successfully formed complexes with BPE with binding affinities for the compound similar to whey protein. Relative helicity of the hemp protein was higher than the other protein sources and increased upon complexation with BPE. Furthermore, the SDS-PAGE profiles of all the proteins were the same whether BPE was present or not and the free amino acid content increased after digestion for the protein and protein/polyphenol solutions. Overall, complexation of BPE with plant proteins was successful. Fluorescence quenching and changes to the secondary structure of the proteins in the presence of BPE indicate that polyphenols were bound but the mechanisms and structures responsible for complexation seem to vary between proteins. More research is needed to determine the interactions that cause binding between the polyphenols and the proteins and whether the bioavailability of the compounds will increase when bound to the proteins in cell model and/or clinical study. This study provides a foundation for exploring the effects of plant-based proteins on phytochemical functionality in complex, "whole food" matrices.
Open Access
Comprehensive characterization of Mycobacterium tuberculosis strains after acquisition of isoniazid resistance
(Colorado State University. Libraries, 2016) Nieto Ramirez, Luisa Maria, author; Dobos, Karen M., advisor; Lenaerts, Anne, committee member; Prenni, Jessica, committee member; Slayden, Richard, committee member
Despite the global efforts to reduce tuberculosis (TB) rates, the emergence of drug resistant TB has not allowed effective control of this disease. In the last decade, there were roughly 10 million new TB cases per year and isoniazid resistant (INHr) TB accounted for 9.5% of these cases around the world. In 2012, United States had an interruption in the supply of isoniazid (INH), which increased the likelihood of INH resistance rates. Although INH resistance in Mycobacterium tuberculosis (Mtb) is multigenic, mutations in the catalase-peroxidase (katG) gene predominate amongst INHr Mtb strains. The characterization of the Mtb proteome before and after acquiring INH resistance remains understudied. Additionally, the effect of these drug-resistance-conferring mutations on Mtb fitness and virulence is variable. The purpose of this work is to describe a complete biochemical and immunological characterization of the INHr acquisition in Mtb. In this way, a global exploration of the protein and mycolic acids differences in Mtb cultures, as well as differences in the immune response and bacterial virulence in the mouse model comparing clonal susceptible and INHr pairs of Mtb were evaluated. After this, common trends were analyzed and the findings were interpreted in the context of bacterial metabolism and host-interaction. For this work, two clonal clinical Mtb strains and one laboratory clonal pair of the H37Rv strain with different susceptibility profiles to INH were studied. The H37Rv INHr strain was isolated from a mouse that was exposed to INH in the lab and developed the same katG mutation that one of the clinical INHr strain has (V1A). In all cases, the first strain was susceptible to all tested drugs (mostly known as the INHs strain in this dissertation) while the second strain was resistant only to INH (named INHr throughout this work). The clinical pairs were confirmed as clonal pairs of the Beijing and T genotype respectively by spoligotyping and restriction fragment polymorphism analysis that uses the patterns given by the distribution of the insertion sequence (IS)-6110. Previous whole genome sequencing analysis of the clinical clonal pairs showed a katG mutation and the presence of some additional non-synonymous polymorphisms in the INHr strains. After the proteomic analysis, a katG PCR sequencing confirmed two mutations in katG for the T INHr pair (V1A and E3V) while the L101R mutation previously identified for the Beijing INHr was not confirmed. This mutation was highly unstable and the Beijing INHr might have reversed its phenotype after the absence of INH during in vitro growth. Therefore, the analysis with the Beijing clonal pair is only presented in chapter II. Protein comparison of secreted and cellular fractions (membrane, cytosol and cell wall) between clinical and lab clonal pairs of Mtb before and after acquisition of INH resistance revealed at least 25 commonly altered proteins looking at the same cellular fractions. These proteins were involved in ATP synthase machinery, lipid metabolism, regulatory events, virulence, detoxification and adaptation processes. Western blot analysis supported some of our findings, particularly the lower level of bacterial enzyme KatG in the INHr strains. Mycolic acid (MA) analysis in these clonal pairs did not reveal a common trend in these molecules for INHr strains but generated supporting information about an alternative fatty acid biosynthetic pathway in the clinical INHr strain. These analyses are further described in chapter III. Additionally, differences in bacterial growth, immune response and pathology induced by Mtb strains harboring mutations at the N-terminus of KatG were evaluated in the C57BL/6 mouse model. The results in the mouse study support the idea of the individual effect of specific located mutations in the katG gene together with the associated changes in the bacterial proteome induce differences in the Mtb virulence and pathogenicity. In addition, the in vivo results also suggest the contribution of innate immune response via TLR-2 in the clearance of the INHr-attenuated Mtb strains. Further details of this work are described in chapter IV. This work provides a better understanding of new compensatory mechanisms in Mtb after INH resistance acquisition providing novel information that could be used to address alternative combined therapies as well as the identification of new drug targets in INHr strains. The results presented here also contribute to the generation of new hypothesis regarding RNA decay in Mtb and the need to evaluate if the observed biochemical differences are also associated with the bacterial exposure to the first line drug therapy that occurred in the patient. After the results obtained in this study, a subsequent biochemical analysis of Mtb strains obtained from patients before and after drug treatment is proposed to improve the description of the evolution of the acquired drug resistant phenomena observed in TB cases that limit the global disease control and hence its eradication (chapter V).
Open Access
Developing integrated pest management (IPM) strategies for hemp russet mite (Aculops cannabicola Farkas) on hemp (Cannabis sativa L.)
(Colorado State University. Libraries, 2022) Hayes, Christopher, author; Nachappa, Punya, advisor; Cranshaw, Whitney, advisor; Prenni, Jessica, committee member
Cannabis sativa L. is a plant that is rapidly becoming a crop of global agricultural importance. However, because of the historical peculiar regulatory status of this crop little has been developed on the pests and pest management needs of the crop. Among the more serious pests that have become established with this plant is hemp russet mite (HRM) Aculops cannabicola Farkas (Acari: Eriophyidae). In order to assess the efficacy of various IPM approaches to mitigating HRM infestations, a series of field and lab experiments were conducted including: 1) evaluation of the effects of sprays of sulfur on control of hemp russet mite, yield, and cannabinoid produduction; 2) evaluation of the efficacy of field release of the phytoseiid mites Amblyseius andersoni, A. swirskii, Neoseiulus fallacis, and N. californicus on HRM-infested hemp plants; and 3) evaluation of hot water immersion as a potential disinfestation method for HRM-infested cuttings used in propagation. The results of the sulfur sprays in field trials showed excellent ability to suppress HRM by up to 98%. Yields of treated plants improved by up to 33% and there was a further increase in the percentage of phytocannabinoids by up to 45% relative to untreated plants. Greatest effects were seen in all trials with plants receiving two applications, one during the vegetative period in July and the second at the initiation of flower production in August. Mass releases of N. fallacis and A. swirskii, but not N. californicus and A. amblysieus, did produce a significant reduction in HRM populations, but no treatments significantly affected yield or percentage of phytocannabinoids, relative to untreated plants. No reproduction was observed of any of the released mites on HRM-infested plants. Immersion treatments to disinfest cuttings included use of a water bath at temperatures of 106°F or 109°F for 10 or 15 minutes, and dips in room temperature surfactant solution of Dr. Bonner's Pure-Castile lavender soap at 1.0% and 0.1% concentrations. All treatments were able to cause significant reduction of HRM on infested hemp cuttings, although none caused complete elimination. No phytotoxicity, as evidenced by effects on subsequent rooting, were observed with any treatment. This study provides novel effective approaches to mitigating HRM at multiple stages in hemp production operations. Outcomes of this research may provide hemp producers and other stakeholders with key pest management strategies needed to produce hemp plants that are free of HRM.
Open Access
Development of a high-throughput phenotyping method for measuring sorghum carotenoids
(Colorado State University. Libraries, 2024) Zapata Carvajal, Nelson David, author; Rhodes, Davina, advisor; Prenni, Jessica, committee member; Weir, Tiffany, committee member
Vitamin A deficiency is the leading cause of preventable blindness in young children, and also leads to infertility and decreased immune function. Humans cannot synthesize vitamin A, so it must be consumed in the diet, either as preformed vitamin A or as provitamin carotenoid (PVACs) in plant foods. Access to PVACs is limited in sub-Saharan Africa where many diets are less diverse and primarily consist of cereals, such as sorghum, with intrinsically low concentrations of PVACs. Therefore, biofortification breeding efforts aim to increase PVACs to biologically relevant levels to reduce global vitamin A deficiency. In order to select and breed high carotenoid varieties, thousands of progeny in a breeding program must be phenotyped. High-performance liquid chromatography (HPLC) is the gold standard carotenoid phenotyping method; however, it is expensive and time-consuming, making it impractical for large-scale screening. We hypothesized that a high-throughput phenotyping (HTP) method using UV-VIS spectrophotometry can identify high carotenoid sorghum lines for selection during breeding. In this study, a simple and rapid method for carotenoid extraction and UV-VIS spectrophotometric detection in a 96-well plate format was developed and validated. To develop the HTP method, we measured 60 samples using both HPLC and UV-VIS, identifying a strong correlation (R2=0.62, p-value<4.51x10-14) between total carotenoid concentrations measured with the HTP method and the gold standard HPLC method. To validate the HTP method, we measured carotenoids in 249 lines in a biparental breeding family, using both HPLC and UV-VIS, and again identified a strong correlation (R2=0.61, p-value<2.2x10-16). We also compared the predictability of the UV-VIS method to that of a simple visual inspection of grain color and found that the UV-VIS method performed significantly better. This promising HTP method will enable rapid screening of a large number of samples, helping breeders more efficiently make selections for carotenoid biofortification.
Open Access
Development of molecular breeding resources for increased pro-vitamin A carotenoids in sorghum grain
(Colorado State University. Libraries, 2022) Cruet-Burgos, Clara María, author; Rhodes, Davina, advisor; Mason, Esten, committee member; Prenni, Jessica, committee member; Pressoir, Gael, committee member
Vitamin A deficiency (VAD) affects millions of people in countries in Africa and South-East Asia, contributing to decreased immune response and increased morbidity and mortality from common infections. Sorghum [Sorghum bicolor L. (Moench)] is a staple cereal crop in these regions, thus, sorghum carotenoid biofortification is a potential method to improve the vitamin A status of these communities. The overall aim of this research was to determine the feasibility of biofortification breeding for sorghum grain carotenoids, and to develop genomic tools to assist in molecular breeding. Global sorghum germplasm collections were evaluated for pro-vitamin A carotenoids, and concentrations were found to be below target values. Due to the low number of accessions with above average pro-vitamin A content, the genetic diversity of the high carotenoid lines in the global germplasm was assessed. High carotenoid accessions were found to be highly related, hence, to increase genetic diversity for breeding, a genomic prediction model was used to identify additional germplasm with potentially high concentrations of pro-vitamin A carotenoids. Through a genome-wide association study, it was confirmed that carotenoid variation in sorghum grain is oligogenic, but there was also evidence of a polygenic component. Therefore both marker-assisted selection (MAS) and genomic selection (GS) may be effective in accelerating breeding efforts. KASP markers in linkage with genomic regions associated with carotenoid concentrations were developed and validated in six F2:3 populations. Two markers in the intronic region of the carotenoid pathway β-OH gene were identified as good candidates to use for MAS due to their predictive ability. A marker inside the coding sequence of the carotenoid pathway ZEP gene was also identified as a good marker for MAS. An RNA-seq experiment identified additional genes in the MEP, carotenoid biosynthesis and carotenoid degradation pathways that could be used for MAS. The results of these studies provide a foundation for vitamin A biofortification through genomics-assisted breeding.
Open Access
Effects of Lubabegron supplementation on carcass traits, muscle fiber type, proteome profile and meat quality attributes of finished feedlot steers
(Colorado State University. Libraries, 2020) Corona, Ashley, author; Nair, Mahesh N., advisor; Belk, Keith E., committee member; Scanga, John A., committee member; Prenni, Jessica, committee member
Two thousand one hundred and sixty (2,160) British and Continental crossbred steers were supplemented (1, 4, 3.2 or 5.0 g/ton (DM basis) Lubabegron and a control diet (Experior; EX, Elanco Animal Health) for the last 28, 56, or 84 d of the finishing period resulting in twelve treatment combinations. Fifteen pens (12 hd/pen) were allocated to each treatment combination consisting of a dose and feeding duration. A total of five harvest cycles were conducted, consisting of 432 head per cycle. Each harvest cycle consisted of 3 blocks, each block contained all dosages and each block was associated with a specific feeding duration. Hot carcass weights (HCW), marbling scores (MS), adjusted fat thickness (aFT), longissimus muscle area (LMA), kidney pelvic and heart fat percentage (KPH), and USDA calculated yield grade (YG) were evaluated for all carcasses (N = 2160). No dose x feeding duration (FD) interaction (P > 0.05) was present for any of the characteristics measured. Supplemented cattle produced heavier (P < 0.05) carcass weights, larger (P < 0.05) LMAs and decreased (P < 0.05) YGs. As feeding duration was extended from 28 to 56 and 84 d, carcass weights were increased (P < 0.05). Control cattle produced MS that were significantly higher than those that were supplemented EX at the highest dose; nonetheless MS remained within USDA Premium Choice (MT00-99). Whereas, EX supplementation did not affect aFT and KPH. A subset of carcasses (N= 540) (3 carcasses/pen) that graded USDA Low Choice (SM00-99) were selected for the purpose of objective color, muscle fiber typing, proteome analysis, and the evaluation of the effect of postmortem aging on tenderness and palatability. As dose increased (P < 0.05) to 3.2 and 5.0 g/ton steaks became less (P < 0.05) red (a*), less (P < 0.05) yellow (b*), and less (P < 0.05) saturated than the controls. Striploin steaks collected during fabrication (before aging) were analyzed for muscle fiber typing (N = 96, n = 8). No detrimental shifts (P > 0.05) were observed for muscle fiber type as it relates to meat quality. The muscle fiber type IIX cross sectional area remained similar across the majority of treatment groups, except for decrease in CSA seen in cattle fed 5.0 g/ton for the final 56 and 84 d of feed. Meat quality attributes were measured using trained sensory panels, slice shear force (SSF) and Warner-Bratlzer shear force (WBSF). Striploins from the right side of each carcass were collected, fabricated into 2.54-cm steaks, and aged for 0, 7, 14, 21, and 28 d postmortem. Steaks for all postmortem aging periods were evaluated using SSF and WBSF, whereas, only those aged for 14 d were evaluated by trained panelists. Non- supplemented cattle produced striploin steaks that were juicier and more tender (P < 0.05) than those from EX supplemented cattle regardless of dose, and no differences (P > 0.05) were observed as a consequence of FD. All steaks (supplemented and non-supplemented) subjected to a minimum 7 d of PM aging produced WBSF that were less than 3.9 kg, and therefore eligible to be labeled as "Certified Very Tender." Once 21 d of postmortem aging was reached, no differences (P > 0.05) in tenderness were observed between the treatments. Based on meat quality attributes, six samples each (N = 24, n = 6) from four treatments (control, low dose for 28 days, high dose for 28 days, and high dose for 84 days) were selected for proteome analysis using a chemical labelling approach know as tandem mass tag (TMT). Experior supplementation influenced expression of proteins involved in muscle contraction, calcium signaling, transport, growth factor, and proteasome activation. Myosin light chain 3 (MYL3) was associated with an improved tenderness and carcass grading, which could be reflective of the increased intramuscular fat content. The proteins identified such as hemoglobin subunit α (HBA), hemoglobin subunit β (HBB), and alpha-1-acid glycoprotein (ORM1) were suggestive of increased vascularization in muscles as a response to EX supplementation.
Open Access
Evaluating the effects of fire on carbon and nitrogen biogeochemistry in forested ecosystems
(Colorado State University. Libraries, 2023) Roth, Holly, author; Borch, Thomas, advisor; Henry, Chuck, committee member; Reynolds, Melissa, committee member; Prenni, Jessica, committee member; Wilkins, Mike, committee member
Forests provide ecosystem services (e.g., carbon storage, nutrient processing, and water filtration) valued at ~$5 trillion per year which are vulnerable to disturbances such as wildfire. Although fires are a natural component of healthy forests, climate change has begun to increase the size, frequency, and severity of wildfires outside of their historic range. Expected increases in burn severity have implications for carbon (C) and nitrogen (N) cycling, with the potential to shift forests from C sinks to C sources due to long delays in tree re-establishment. There is great interest in resolving changes to soil organic matter (SOM) composition, especially organic nitrogen, to predict how forests respond to wildfires. Therefore, the purpose of the work included in this dissertation was to improve nitrogen analysis in fire-impacted forest systems and apply these methods to soil and water samples. In the following work, a suite of advanced analytical approaches were used to determine the molecular composition of SOM, which was evaluated for the impacts of severe wildfires on microbially-mediated SOM processing and water quality in fire-impacted watersheds. Field-based soil and water samples were collected from subalpine forests in the Colorado Rocky Mountains and investigated for shifts in the water-soluble and solid fractions of SOM in lodgepole pine-dominated forests and their influence on microbial processing and water quality was determined. The objectives of this study were to leverage ultrahigh mass spectrometry to improve N analysis in fire-impacted systems (Objective 1), determine the post-fire changes to surface water C and N chemistry in reducing conditions (Objective 2) and to characterize how fire severity influences SOM composition along soil burn severity gradients (Objective 3). Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) currently achieves the highest mass resolving power in the world, which allows for the study of complex mixtures with tens of thousands of compounds that are separated by the mass of an electron across a wide molecular weight range. The most widely used FT-ICR MS analytical approach uses negative-ion mode electrospray ionization (-ESI) to selectively ionize highly abundant carboxylic acids in SOM. The application of this approach has allowed for rigorous analysis of C composition; however, -ESI FT-ICR MS vastly underestimates N-dense species which are formed during combustion. The biases associated with ionization are propagated in chemical property calculations that are determined by elemental compositions and which must be fully understood for proper use in C and N cycling models. We compared traditional -ESI with positive-ion mode electrospray ionization (+ESI) of burned soil extracts and found that +ESI increased compositional coverage by 87%, including nearly 10,000 additional N species (Objective 1). We applied our +ESI FT-ICR MS findings on a burn severity gradient (low, moderate, and high severity) to evaluate the compositional changes to SOM with increasing severity, with a specific focus on organic nitrogen. We collected soils from burned lodgepole pine forests along the Colorado-Wyoming border from two depths to characterize changes to organic N chemistry. Since organic N is the most abundant form of soil N in conifer forests, a better understanding of post-fire organic N will help address a critical gap in our understanding of fire severity-induced changes in the molecular composition of soil organic nitrogen. Nuclear magnetic resonance spectroscopy and FT-ICR MS analysis showed that N content and aromaticity of water-extractable SOM (0-5 cm depth) increased with burn severity, while minimal changes to the 5-10 cm depth were observed. Heterocyclic N species are generally higher in toxicity compared to their non-nitrogenated counterparts, which prompted soil toxicity measurements. We used Microtox ® to determine that soil toxicity increased with increasing burn severity, which may be partly attributed to newly formed N-species (Objective 2). In conjunction with increased fire activity, North American beaver (C. canadensis) populations have steadily increased since the early 1900s. The ponds that beavers create slow or impound hydrologic and elemental fluxes, increase soil saturation, and have a high potential to transform redox active elements (e.g., oxygen, nitrogen, sulfur, and metals). While surface water runoff composition has been studied in many environments, the effects of reducing conditions (i.e., beaver ponds) on these products are not well known. We collected surface water and sediment samples to investigate the impact of beaver ponds on the chemical properties and molecular composition of dissolved forms of C and N, and the microbial functional potential encoded within these environments from a combination of FT-ICR MS and metagenomics. We found that N-containing compounds and aromaticity increased in the surface water of burned beaver ponds, and that C/N and O/C ratios decreased. Microbial communities within the ponds did not have the capacity to process aromatic species, but they did have the potential for anaerobic metabolism and the potential to respire on microbial necromass (Objective 3). Fires burn heterogeneously across the landscape, and overstory vegetation likely plays a large role both in the way fires burn and how soils recover post-fire. Site factors such as soil type affect the interactions of SOM with abiotic soil components and can have cascading effects on soil C storage, including SOM partitioning between particulate organic matter (POM) and mineral associated organic matter (MAOM). POM is generally considered to have a faster turnover time than MAOM, which is physically protected from microbial degradation. Soil under two common trees in Colorado (lodgepole pine and aspen) are known to differ in SOM quantity and composition, including their relative proportions of POM and MAOM but post-fire products in these soils are relatively uncharacterized. To determine the differences in post-fire SOM between aspen and pine soils, we collected soils from under aspen and pine stands and burned them in open-air pyrocosms to minimize environmental variables which confound field-based studies. We concluded that fire influenced the dissolved fraction of the soils, with higher concentrations of dissolved organic carbon, dissolved total nitrogen, ammonium-N, and nitrate-N in burned aspen soil extracts. To determine the implications for less bioavailable carbon fractions, we will determine %C and %N in soils that have only been dried and sieved, as well as separated into POM and MAOM. We will also characterize the dissolved fractions using FT-ICR MS and NMR to evaluate differences in soil functional groups. Complementary microbiome analyses will be performed to determine the implications of shifts in soil functionality for microbial processing and C and N sequestration. The novel application of +ESI in this dissertation allowed for the identification of increasingly N-dense species at high burn severities which were not previously observed in field samples. N-dense species are enriched under reducing conditions as they are unable to be processed by local microbial communities. In total, these findings contribute to our understanding of newly formed organic C and N species in soils, with implications for microbial activity in fire-affected watersheds.
Open Access
Impact of inoculum source and primary carbon source on biotransformation of pharmaceuticals and personal care products
(Colorado State University. Libraries, 2017) Kim, Sunah, author; De Long, Susan, advisor; Sharvelle, Sybil, committee member; Omur-Ozbek, Pinar, committee member; Prenni, Jessica, committee member
To view the abstract, please see the full text of the document.
Open Access
Impacts of operating conditions on aerobic removal of emerging contaminants from animal waste: composting post anaerobic digestion
(Colorado State University. Libraries, 2019) Larson, Victoria J., author; De Long, Susan, advisor; Sharvelle, Sybil, committee member; Prenni, Jessica, committee member
To view the abstract, please see the full text of the document.
Open Access
Influence of preharvest factors on peach fruit quality and metabolism
(Colorado State University. Libraries, 2021) Anthony, Brendon, author; Minas, Ioannis, advisor; Musacchi, Stefano, committee member; Prenni, Jessica, committee member; Bunning, Marisa, committee member
Worldwide peach consumption has been in steady decline throughout the past few decades due to poor fruit quality and consumer experiences. Fruit quality is developed in the orchard by optimizing preharvest factors and orchard practices. Several studies have been conducted to understand how these factors influence peach internal quality, but fail to control for confounding variables. One particular confounding variable that is influenced by preharvest factors and directly impacts fruit quality is maturation. Pomological experiments investigating the impact of preharvest factors on internal fruit quality must control for maturity. Historically, maturity control through destructive and subjective methods was not feasible nor efficient. The development of new technologies, such as visual radiation and near-infrared spectroscopy allowed the development of novel maturity indices (index of absorbance difference) that can be used for maturity control and quality assessment simultaneously in a single scan. The following literature review and experiments investigate three critical preharvest factors: training systems, canopy position and crop load (i.e., carbon supply), for their true impact on peach fruit quality development and metabolism, while controlling for maturity. The training system review demonstrates the progression of orchard design from three-dimensional, low-planting densities to planar, high-density plantings through the application of size-controlling rootstocks and vigor diffusion architecture. The canopy position trial revealed that the fruit's light environment is more influential in quality development and metabolic shifts than genotype or position alone. Canopies with uniform light distribution generate fruit of uniform quality and metabolite profiles across distinct positions. Fruit under sufficient carbon supply (i.e., thinned fruit) will exhibit superior quality and phenotype when compared to carbon-starved fruits at harvest, even when assessed at equal maturity. Primary metabolite profile differences between distinct carbon supply conditions are minimal at harvest due to experimental maturity control and metabolic processes being heavily regulated by development and maturation. While differences in secondary metabolite profiles are more distinct at harvest between carbon supply treatments. Although, both the primary and secondary metabolism demonstrate vast profile differences between carbon supply treatments early, and may prime the quality phenotype at harvest. Flavonoids are consistently elevated in carbon sufficient fruit throughout development. Phenylpropanoids, such as catechin, along with benzenoids, sucrose and sorbitol demonstrate strong relationships with high-quality fruit throughout experiments, while lipids, amino acids, monosaccharides and organic acids showcase relationships with inferior quality fruit. Overall, maturity control is necessary in pomological experiments assessing the true impact of preharvest factors on fruit quality and metabolism.
Open Access
Integrating p300 functions in HTLV-1 transcription initiation
(Colorado State University. Libraries, 2014) Luebben, Whitney R., author; Nyborg, Jennifer K., advisor; Stargell, Laurie, committee member; Laybourn, Paul, committee member; Prenni, Jessica, committee member; Quackenbush, Sandra, committee member
The HTLV-1 provirus overcomes a repressive chromatin environment for efficient transcription of its genome. This is accomplished by the robust recruitment of the coactivator protein, p300, to the viral enhancer sites through interactions with DNA bound pCREB and the viral transactivating protein, Tax. Recruitment of p300 to the HTLV-1 promoter results in histone acetylation and nucleosome depletion from the promoter region in the presence of the histone chaperone, Nap1. To study the histone acetylation requirements for Nap1-dependent nucleosome disassembly, we utilized immobilized in vitro assembled chromatin templates containing site specific K→R mutations within the N-terminal tails of the histones. Through these studies, we identified histone H3, lysine 14 as the functionally relevant acetylation site for Nap1-dependent nucleosome disassembly. Additionally, we found a significant correlation between nucleosome disassembly from the HTLV-1 promoter and acetylation-dependent transcription activation. These studies suggest that nucleosome disassembly is a prerequisite for transcription activation, as nucleosome disassembly creates a nucleosome free region within the HTLV-1 promoter, allowing for the subsequent recruitment of Pol II and general transcription machinery for activation of transcription. The identification of a single and specific acetyl-lysine residue led us to the hypothesis that the p300 acetyl-lysine binding domain (bromodomain) was involved in HTLV-1 transcription activation through recognition of H3K14ac. To test this hypothesis, we utilized a p300 bromodomain deletion mutant and a CBP/p300 specific bromodomain inhibitor, (SGC-CBP30), to investigate the involvement of the p300 bromodomain in HTLV-1 transcription activation. Importantly, we found that the p300 bromodomain is not involved in the initial recruitment of the coactivator to the chromatin template as previously proposed, rather the bromodomain functions after recruitment to the promoter and following acetylation of the histone tails. These findings are consistent with a role for the p300 bromodomain in nucleosome disassembly and uncover a novel function for the bromodomain in gene activation.
Open Access
Mining the Mycobacterium tuberculosis cellular envelope for diagnostic and drug targets
(Colorado State University. Libraries, 2013) Wolfe, Lisa Marie, author; Dobos, Karen M., advisor; Belisle, John T., committee member; Dow, Steven, committee member; Lewinsohn, David, committee member; Prenni, Jessica, committee member
The cellular envelope of Mycobacterium tuberculosis is a highly complex structure containing many lipids, carbohydrates and proteins. Together these components maintain cellular homeostasis and play an active role in the establishment and maintenance of intracellular infection. The World Health Organization estimates that upon exposure, 90% of infected persons will not succumb to active disease and likely remain a potential source of M. tuberculosis transmission upon the emergence of clinical symptoms. Throughout this complex disease course, physiological and structural changes occur within the cell envelope of the bacillus and facilitate its survival within an infected host. These physiological changes also influence the immunological interplay between bacteria and host cell, further contributing to the success of the pathogen. To understand these changes we must have a comprehensive knowledge of the cell wall proteins that contribute to the overall makeup of the mycobacterial envelope, understand the unique antigens that reside in or that are secreted from the bacillus and monitor these proteins under different physiological disease profiles. In the last decade many large-scale descriptive studies focusing on gene transcript profiles and proteomic composition of subcellular fractions have pioneered efforts in the understanding of M. tuberculosis physiology, immunology and pathogenesis at the level of systems biology. These studies have shown that M. tuberculosis is capable of retaining essential gene products for respiration, nutrient uptake and energy metabolism both in vitro and in vivo and that the proteins within the cell wall are highly immunogenic for M. tuberculosisspecific T lymphocytes. Our first objective established a comprehensive description of the cell wall proteome of M. tuberculosisusing traditional two-dimensional gel-based techniques and liquid-chromatogoraphy mass spectrometry (LC-MS). From this work, over 500 proteins were identified using a combination of differential detergent extraction and multi-dimensional-LC. A highly lipoprotein enriched fraction revealed that the majority of cell wall associated proteins were functionally annotated to mechanisms of intermediary metabolism (35%) and macromolecular synthesis and degradation (25%) building upon evidence that the M. tuberculosis cell wall is actively engaged in cellular homeostasis and remodeling events. Secondly, we investigated the role of the cell envelope proteins in the search for novel immunodiagnostic epitopes. It is well known that the cell wall of M. tuberculosis is highly immunogenic and contains both non-protein and protein antigens. Specifically, the proteins associated with the cell wall were shown to be uniquely responsible for the activation of human CD8 T cell clones generated from both actively and latently infected individuals. The immunological response to CD8 T cell antigens may be an effective means of distinguishing between latent TB infection (LTBI) and active disease. To broadly define the repertoire of CD8 T cell antigens, 56 proteins from the cell wall proteome study were included in the design of a synthetic peptide library. Exhaustive screening of the peptide library for novel antigens and epitopes that elicit an immunological response in TB patients, resulted in the identification of eight cell wall antigens that are currently being investigated for their clinical utility. In addition, the cell wall proteome was also mined in the identification of an HLA-E restricted CD8 T cell epitope. HLA-E has low polymorphism in the human population and seems to be enriched in M. tuberculosis - containing phagosomes, therefore identification of this antigen could be used as a novel diagnostic or vaccine candidate. Using a MS-based proteomics approach, we discovered the HLA-E antigen to be the post-translationally modified glycoprotein Mpt32 (45kDa/Apa). Glycosylated proteins and lipids within the mycobacterial cell envelope are dominant and the role of this modification in the host immune response can now be elucidated. Lastly, the composition and integrity of the M. tuberculosiscell envelope facilitates its adaptation and survival within various microenvironments. These physiological functions are influenced by the presence or absence of functionally linked genes and proteins whose relative abundance may change over time or within altered metabolic states. Our final efforts used nucleotide analog probes, to specifically bind and enrich proteins with an ATP-binding function and measure their relative abundance between altered states of growth (i.e. between active disease and hypoxia-induced dormancy). With these efforts we classified 122 ATP-binding proteins in either metabolic state and demonstrated differential abundance patterns between actively growing and hypoxic cells within the functionally linked protein networks of energy metabolism, cell wall and lipid biosynthesis. These protein families represented in the M. tuberculosis ATPome are a subset of essential (60% of the Mtb-ATPome) gene products and may be relevant therapeutic targets for the future development of novel small molecule inhibitors against M. tuberculosis. The spectrum of studies undertaken to mine the cellular envelope for diagnostic and drug targets demonstrates a natural evolution of MS-based proteomics in the study of biologically relevant questions. From a purely descriptive characterization of the cell wall proteome, this data was utilized in a practical approach in the design of a high-throughput antigen/epitope-screening library and finally these studies culminate in a functionally relevant profile of the ATP-binding proteins of M. tuberculosis. Future work will continue to focus on developing hypothesis-driven proteomic studies for the identification of novel diagnostic antigens and drug targets.
Embargo
Molecular and sociocultural exploration of sourdough: impacts on gluten sensitivity and bread characteristics
(Colorado State University. Libraries, 2023) Clark, Caitlin, author; Van Buiten, Charlene, advisor; Stone, Martha, committee member; Weir, Tiffany, committee member; Gentile, Chris, committee member; Prenni, Jessica, committee member
Sourdough is a bread product fermented by communities of wild bacteria and fungi known as a starter culture. Previous work has examined the effects of specific starter organisms on bread quality, but the relationships between whole microbiomes and dough/bread physicochemical properties are currently unknown. The objective of this study was to investigate the relationship between physicochemical properties of sourdough breads and the microbiomes of their starter cultures. Twenty sourdough starters with characterized microbiomes were used to produce wheat-based dough and bread. The chemical properties (pH, titratable acidity, free amino acids, Aw) of dough and physical properties (loaf volume, crust color, texture) of the breads were compared to a control fermented with baker's yeast. The degradation and toxicity of gliadin resulting from fermentation with the sourdough samples was also studied in vitro. Results indicate that sourdough-fermented breads produced under real-world conditions are distinct from yeast-fermented bread in terms of physicochemical parameters and proteolysis, which may exert downstream effects on the inflammatory capacity of gluten. We also investigated the beliefs and behaviors of gluten-sensitive sourdough consumers and professional sourdough bakers. We found that commercial sourdough is not reported to relieve gluten-mediated symptoms for consumers diagnosed with celiac disease (CD) or non-celiac gluten sensitivity (NCGS), but undiagnosed (UD) gluten-sensitive consumers may benefit from it. We also determined that sourdough bakers act as brokers of health advice in the gluten-sensitive community.