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Browsing by Author "Broeckling, Corey, committee member"

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    Characterizing smoke taint in hops (Humulus lupulus) and investigating the impact of defoliation stress on phytocannabinoid content in industrial hemp (Cannabis sativa)
    (Colorado State University. Libraries, 2024) Sandoval, Brandon, author; Prenni, Jessica, advisor; Rhodes, Davina, committee member; Broeckling, Corey, committee member
    The family Cannabaceae contains at least 10 genera, with Cannabis (hemp) and Humulus (hop) being two of the most economically important. Both genera have long been valued by humans for their chemical constituents and are used today for both medicinal and recreational purposes. However, adverse environmental factors may impact the chemical profile of these important crops, leading them away from a true-to-type quality. This thesis will explore the effects of an abiotic stress on the chemical profile of each crop: smoke-taint in hops and defoliative hail damage of hemp. The Pacific Northwest contains 97.5% of U.S. commercial hop acreage and has also seen an increase in the number and severity of wildfire events in recent years. While there is extensive research from the wine industry on the impact of smoke taint in grapes, our knowledge of smoke taint in hops is limited. Here, we aimed to characterize smoke taint in hops using laboratory simulated wildfires with distinct fuel types and non-targeted gas chromatography-mass spectrometry. Our results reveal an overall variation in the chemical profiles between smoked and control hops and across fuel types and the detection of known and novel smoke taint markers including guaiacol, 4-methylguaiacol, and xylopyranose. This research provides evidence to support the use of established smoke taint markers for hop analysis and lays the groundwork for future studies to investigate various fuel types and their impact on hop quality. The United States has seen an abrupt increase in commercial industrial hemp production since the Agricultural Improvement Act of 2018. However, the historical prohibition of this crop has resulted in a lack of basic physiological research to guide management practices. For example, abiotic stress can stimulate plants to increase production of secondary metabolites such as phytocannabinoids and this is of high importance to farmers as they as they must balance optimization of CBD yield (crop value) with regulatory requirements (THC < 0.3% by mass) that could lead to crop loss (mandated destruction). In this study we evaluated the impact of defoliation stress (to simulate hail damage) at three different growth stages. Our results indicate that defoliation stress during late flowering yielded no significant change in phytocannabinoid production. However, defoliation stress during vegetative and early flowering yielded a significant increase in phytocannabinoids, including total CBD and THC, at harvest.
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    Influence of barley genetics on beer chemistry, flavor, and flavor stability
    (Colorado State University. Libraries, 2017) Bettenhausen, Harmonie M., author; Bunning, Marisa, advisor; Heuberger, Adam, advisor; Avens, Jack, committee member; Broeckling, Corey, committee member; Stone, Martha, committee member
    In the brewing industry, identifying superior ingredients that provide distinct flavors is an important area of research. While the contribution of raw ingredients such as yeast and hops to flavor is well understood, it is currently unclear if different genotypes of barley provide unique flavor to beer. In brewing, barley is malted to provide saccharides and enzymes for fermentation, however the malt also contains thousands of metabolites that may influence flavor. The goals of this study were to determine (i) if there would be metabolite differences among six commercial barley genotypes, (ii) if differences in barley chemistry are reflected in the chemistry of the beer, (iii) if the differences in the beer chemistry impact sensory attributes of beer, through flavor and flavor stability, and (iv) if there are barley and/or malt metabolites that can be markers for beer flavor and/or flavor stability. Six distinct malts were brewed into six beers using a recipe designed to evaluate differences in flavor. The malts were derived from the barley genotypes: Copeland, Expedition, Full Pint, Meredith, Metcalfe and PolarStar were grown and malted in either Canada or the U.S. Metabolomics was used to characterize chemical variation among the six malts and beers using RP-UHPLC-MS, HILIC-MS (non-volatile metabolites), HS/SPME-GC-MS (volatiles), and ICP-MS (metals). The metabolomics analysis detected 5,042 compounds in malt, and 217 were annotated as known metabolites and included amines (20 metabolites), amino acids (36), fatty acids/lipids (40), sugars (11), phenols (30), and others (80). A total of 4,568 compounds were detected in beer and included 246 annotated metabolites and included amines (9), amino acids (37), fatty acids/lipids/fatty acyls (28), sugars (10), phenols (20), esters (89), aldehydes (21), others (31). The chemical profiles of the six malts and beers were evaluated for metabolite variation using principal component analysis (PCA) and analysis of variance (ANOVA). Principal component analysis was conducted on the annotated metabolites and demonstrated that each of the six malts and beers contained unique chemical profiles. ANOVA characterized 150/217 malt metabolites (69.1%) and 150/246 beer metabolites (60.9%) varied among genotype (ANOVA, FDR adjusted p < 0.05). The six beers were evaluated for flavor using a modified Quantitative Descriptive Analysis® (QDA) for 45 sensory traits at 0, 4, and 8 weeks of storage at 13 °C. PCA characterized flavor differences among the six beers at 8 weeks and Full Pint was described as fruity and Meredith as corn chip. The metabolite and sensory data were integrated using two approaches: Spearman's correlation and two-way orthogonal projection to latent structures (O2PLS). The analyses revealed associations between fruity or corn chip flavor in beer with beer purines/pyrimidines, volatile ketones, amines, and phenolics; and malt lipids, saccharides, phenols, amines, and alkaloids. Taken together, these data support a role of barley metabolites in beer flavor and flavor stability. As a raw ingredient, malted barley genotypes should be evaluated for a contribution to flavor, and this may be a future target for plant breeding efforts to selectively improve flavor and flavor stability quality in beer.
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    Phenotypic plasticity in the response of sorghum to water stress and recovery indicates pre-flowering drought tolerance
    (Colorado State University. Libraries, 2018) Miller, Sarah Bethany, author; Jahn, Courtney, advisor; Argueso, Cris, committee member; Broeckling, Corey, committee member; Leach, Jan, committee member
    To view the abstract, please see the full text of the document.
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    Probing the metabolic secrets of Anopheles stephensi mosquitoes to enhance cryopreservation techniques
    (Colorado State University. Libraries, 2024) Ramirez, Gabriela, author; Dobos, Karen, advisor; Ebel, Greg, committee member; Barfield, Jennifer, committee member; Broeckling, Corey, committee member
    The lipid profile and cryopreservation methods of Anopheles stephensi mosquitoes have significant implications for mosquito management and research. The intricate life cycle of mosquitoes is governed by lipid metabolism, involving lipogenesis, lipolysis, and fatty acid metabolism, which are critical for transitioning between life stages. Despite the importance of these processes, mosquito cryopreservation has faced challenges, mainly due to the impenetrable nature of mosquito eggs to traditional cryoprotective agents. While other insects like honeybees and fruit flies have seen some success in cryopreservation, mosquitoes have posed unique difficulties. Initial attempts to cryopreserve mosquito eggs were unsuccessful, and there remains a need for effective cryopreservation protocols that maintain the viability and normal development of mosquitoes post-thaw. This study investigates lipid metabolism across mosquito life stages and advances cryopreservation techniques. The lipid profile analysis focused on major lipids such as phosphatidylcholine (PC), phosphatidylethanolamine (PE), sphingomyelins (SM), and triacylglycerides (TGs), as well as non-bilayer lipids like diacylglycerol (DG) and lysophospholipids (LysoPC, LysoPE). For cryopreservation, a new protocol using methylformamide (MF) with trehalose was developed for first-instar larvae (L1s) older than 1.5 hours post-hatching. The hypotheses were that 1) Lipid metabolism plays a crucial role in the successful development and reproduction of mosquitoes, and 2) Inducing diapause and using suitable cryoprotectants can improve the recovery rates of cryopreserved mosquitoes. The lipid profile analysis revealed that PE is vital for protein anchoring required for embryogenesis and immune responses and that steroids like 20-hydroxyecdysone (20E) are crucial for molting and development. The cryopreservation study showed that supercooling larvae for up to 60 minutes resulted in normal development to adulthood, although longer durations inhibited adult emergence. Supercooled larvae and their offspring exhibited typical sex ratios and developmental patterns, indicating genetic and phenotypic stability. This research underscores the well-orchestrated metabolic strategies in mosquitoes. It suggests that understanding these biochemical processes is essential for effective cryopreservation, potentially paralleling natural cold survival strategies seen in other insects.
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    Supplementing powdered high-fiber foods to alter gut microbial metabolism for colorectal cancer prevention
    (Colorado State University. Libraries, 2016) Sheflin, Amy Marie, author; Weir, Tiffany, advisor; Broeckling, Corey, committee member; Melby, Chris, committee member; Pagliassotti, Michael, committee member
    Trillions of microorganisms populate the human digestive tract and enhance immunity, improve digestion and inhibit pathogens when in healthy balance. However, a disruption of gut community balance is associated with a number of diseases including colorectal cancer (CRC). The purpose of this research was to investigate supplementation with two high-fiber foods, heat stabilized rice bran (SRB) and cooked navy bean powder (NBP), for potential to favorably alter the intestinal environment for CRC prevention. Study 1 aimed to assess differences in stool microbiota and associated metabolites in healthy individuals versus those diagnosed with CRC. Next, two pilot dietary interventions were undertaken (Study 2 and 3), one in healthy individuals and another in CRC survivors. Both pilot studies provided diets supplemented with SRB or NBP or macronutrient matched control foods and changes in stool microbiota and associated metabolites were assessed at baseline and after 2 and 4 weeks. The collective body of this research supports the hypothesis that gut microbiota and their metabolites differ with respect to CRC and that intervention with SRB or NBP can alter this profile. Despite similar increases in dietary fiber intake, SRB induced more significant change to gut microbiota and metabolites possibly due to differing chemical composition of plant fibers. Relative to NBP, SRB is rich in arabinoxylans, which structurally mimic the protective mucins lining the intestinal surface. Changes in both microbiota and metabolites observed with SRB supplementation are consistent with enrichment of glycan-foraging bacteria able to switch between dietary glycans (arabinoxylans in this case) and host glycans for energy. Acetate and propionate, potentially beneficial byproducts of microbial fermentation of glycans and other fiber components, increased at 2 weeks in CRC survivors. However, some of the observed changes did not persist at 4 weeks and further research is necessary to determine if more lasting changes are possible with these dietary interventions, as well as whether these altered microbial/metabolite profiles are associated with reduced risk of CRC incidence and recurrence.
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    Understanding the molecular basis of insect pest resistance in Triticum aestivum using mass spectrometry
    (Colorado State University. Libraries, 2018) Lavergne, Florent D., author; Heuberger, Adam, advisor; Broeckling, Corey, committee member; Pearce, Stephen, committee member; Jahn, Courtney, committee member
    Bread wheat (Triticum aestivum L.) is a global staple crop and controlling for environmental stress that impacts grain yield is critical. Recently, Wheat Stem Sawfly (Cephus cinctus, hereafter WSS) has emerged as a new pest of wheat and is expanding across the Great Plains and southern United States. WSS is difficult to control using chemical, cultural or biological pest management methods. Currently, wheat breeders utilize a solid-stem trait to inhibit larval feeding and reduce lodging, however this trait only confers partial resistance and is thought to reduce grain yield. Models of metabolic-based resistance with demonstrated impact on reduction of insect pest fitness have been documented. Here, I investigate the broader hypothesis that wheat resistance to WSS is mediated by shifts in metabolism that promote avoidance and toxicity towards WSS. Four cultivars with contrasting phenotypes are used in our studies: Hatcher (resistant to WSS, hollow-stem, winter wheat); Conan (resistant, semi-solid-stem, spring); Denali (susceptible, hollow-stem, winter); and Reeder (susceptible, hollow-stem, spring). The first part of this work involved gas chromatography-mass spectrometry (GC-MS) metabolomics methods to provide a comprehensive characterization of the chemical composition of wheat cuticular waxes. A total of 263 putative compounds were detected among the four abovementioned wheat cultivars and comprised 58 wax compounds including alkanes and fatty acids. Many of the detected wax metabolites have known associations to important biological functions such as insect pest and drought resistance. Uni- and multivariate statistics were used to evaluate metabolite distribution between tissue types (leaf, stem) and cultivars. Leaves contained more primary alcohols than stems such as 6-methylheptacosan-1-ol and octacosan-1-ol. The metabolite data were complemented using scanning electron microscopy of epicuticular wax crystals which detected wax tubules and platelets. Conan (resistant to WSS) was the only cultivar to display alcohol-associated platelet-shaped crystals on its abaxial leaf surface. The second part of this study aimed at evaluating a selection of wheat cultivars in a WSS-infested field. Cultivars with increased yield and reduced WSS infestation values were found. The molecular basis of this resistance was evaluated in a greenhouse study that characterized proteomic and metabolomic signatures of wheat stems associated with WSS infestation. Stem proteins (1832) and metabolites (1823) were detected in the same four wheat cultivars using liquid chromatography-mass spectrometry. During infestation with WSS, 62 proteins and 29 metabolites were differentially regulated in the hollow-stem resistant cultivar Hatcher. Metabolic processes that were associated with resistance included enzymatic detoxification, proteinase inhibition, and anti-herbivory compound production, specifically the benzoxazinoids, neolignans, and phenolics. Compared to the semi-solid and resistant cultivar Conan, hollow-stem Hatcher had increased abundance of proteins and metabolites with known roles in plant defense against insects. These results will be invaluable to plant breeders as they contribute to the understanding of wax composition and metabolic regulation associated with important phenotypic traits in a major crop, including passive and active defense mechanisms to WSS.