Microbiological Sciences

Permanent URI for this communityhdl:10365/32427

Research from the Department of Microbiological Sciences. The department website may be found at https://www.ndsu.edu/micro/

Browse

Browsing Microbiological Sciences by browse.metadata.program "Microbiological Sciences"

Filter results by typing the first few letters
Now showing 1 - 5 of 5
  • No Thumbnail Available
    Item
    Effects of Intensive Agricultural Management Practices on Soil Microbial Assembly and Recruitment
    (North Dakota State University, 2022) Sciences, Microbiological; Nath, Debdutta
    Soil microbial communities play an important role in ecosystems in various ways to promote healthy and fertile soil. However, intensive agricultural practices with excessive tillage and fertilizer applications can affect the abundance and community structure of microbial communities in soil as well as their assembly and recruitment by plant roots. Using amplicon sequencing and microscopy, we have examined bacterial and fungal communities under different tillage and fertilizer treatments in a 34-year-old field-trial at the Carrington Research Extension Center of NDSU. We observed that fertilizer application has a significantly stronger effect than tillage on soil properties, as well as the overall soil microbial abundance and community structure. Significantly higher mycorrhizal colonization was found under organic manure application. Overall, the results of this study can improve our understanding of the effects of fertilizer application on soil microbial communities and how management practices can be optimized to reduce the imprints of intensive agriculture.
  • No Thumbnail Available
    Item
    In the Pursuit of Poultry: β-Phenylethylamine and Ethyl Acetoacetate as Antimicrobials on Chicken
    (North Dakota State University, 2022) Bauer, Erika Shay Hedrick
    This research examines the effect of β-phenylethylamine (PEA), a natural trace amine commonly found in food, and ethyl acetoacetate (EAA), an FDA approved flavoring agent and food additive, as novel antimicrobials on store-bought chicken thighs in a 5-minute immersion. In the first part of this experiment, 5%, 7.5%, and 10% treatments of β-phenylethylamine and ethyl acetoacetate were compared to control H2O treatments utilized on chicken thighs. 10% treatments of PEA and EAA had significant reductions in counts of total aerobic bacteria and Pseudomonas spp. grown at 20°C by >1 log10 CFU/g of chicken meat. In the next experiments regarded 10% EAA as an antimicrobial on potential pathogens on chicken meat. The treatments of 10% EAA only succeeded in partial efficacy in the reduction of inoculated Salmonella spp. and Campylobacter spp. on chicken thighs.
  • No Thumbnail Available
    Item
    The Link Between Gut Microbiota Metabolism and Host Gluconeogenesis by Vasoactive Intestinal Peptide
    (North Dakota State University, 2022) Dawlaty, Razia
    The gut microbiota (GM) plays a beneficial role in host metabolism. In mammals, the GM ferments dietary fiber into short chain fatty acids (SCFA), like propionate, that improves glucose metabolism. Rats fed a propionate diet increased intestinal gluconeogenic (IGN) gene expression, which was blocked by treatment with the neurotoxin, capsaicin, suggesting a neuronal-dependent mechanism. We hypothesized that the gut neuropeptide, vasoactive intestinal peptide (VIP), links GM derived propionate to IGN expression. We fed VIP deficient mice a 5% propionate chow diet (n=60) for 2 weeks and measured mRNA levels for GN genes by dPCR. Basel intestinal and liver GN mRNA expression was dysregulated by the loss of VIP. GN mRNA levels in liver were differentially altered in males versus females fed a propionate diet in a VIP-dependent manner. We conclude that VIP regulates basal intestinal and hepatic GN mRNA expression and mediates propionate induced GN mRNA changes in liver.
  • No Thumbnail Available
    Item
    Rationally Reconstructed and Attenuated Vaccines for Epidemic Response
    (North Dakota State University, 2021) Rakibuzzaman, AGM
    Most of the recent viral outbreaks were caused by highly mutating RNA and single stranded DNA viruses. The availability of safe and effective rapid response vaccines early on in an epidemic situation, along with good vaccine delivery systems, is critical for pandemic response plans. Additionally, immunodominance patterns in the host response to epitopes in vaccine antigens can complicate immune responses to vaccines. In this thesis, using porcine circovirus type 2 (PCV2) as a model, we have focused on changing viral immunodominance patterns to rationally improve vaccine efficacy. We hypothesized that rational alteration of the immunodominant decoy epitope would remove nonprotective antibody response and improve the overall quality of neutralizing antibodies. As hypothesized, the antibody response to the target immunodominant epitopes were abrogated in the vaccinated pigs, and they were protected upon with the challenge of a heterologous strain PCV2d. To ensure the safety of the rationally restructured PCV2 vaccine, we have developed novel strategy to ensure suicidal replication of the vaccine virus in vivo. We hypothesized that recoding serine and leucine codons of the PCV2 capsid gene will increase the probability of accumulating stop mutations during viral replication. As expected, immunized pigs with the suicidal vaccine, protected them against PCV2d heterologous challenge. Furthermore, subjecting the suicidal vaccine construct to in vitro immune pressure with sub-neutralizing serum, resulted in an accumulation of stop mutations and abortive replication. Finally, using porcine epidemic diarrhea virus (PEDV) as a model, we have developed an effective oral delivery system for a rapid response vaccine. Treatment of PEDV with heat to denature the capsid, followed by RNase to fragment the RNA genome, resulted in a minimally replicative vaccine which was highly effective in weanling piglets. Here, we determined treatment conditions to either completely inactivate or rapidly attenuate PEDV. To improve oral delivery of the vaccine to sows, biodegradable niosome formulation composed of edible lipid, cholesterol, and charge stabilizer was optimized. The antigen loading capacity of the niosome was over 80% with minimal cellular cytotoxicity. In summary, the methods described in this thesis have addressed three major gaps in vaccinology and have broad applicability in the field.
  • No Thumbnail Available
    Item
    Sexual Dimorphisms in the Adipose Biology of Vasoactive Intestinal Peptide Deficient Mice
    (North Dakota State University, 2022) Hawley, Emma
    Both VIP and PACAP deficient mice display impaired fat storage, but only the molecular adipose characteristics of PACAP KO mice are known. While mice deficient in these peptides are lean, supplementation could promote weight gain in livestock after establishing tissue distribution. We investigated both sides of this 'metabolic coin' by measuring serum metabolites, adipocyte area, and pscWAT gene expression in VIP deficient mice and screening 15 ruminant tissues for VIP, PACAP, and their receptors using RT-qPCR. We found male VIP deficient mice displayed hypertrophic adipocytes, low serum FFAs, and suppressed relative mRNA expression of TMEM26. In ruminants, VIP and PACAP showed similar expression patterns, whereas their receptors had divergent tissue distributions. We conclude that VIP deficiency affects the investigated adipose characteristics in male but not female mice. Additionally, we predict that VIP supplementation in ruminants would promote weight gain since its mRNA distribution is similar to mice.