Open Access. Powered by Scholars. Published by Universities.®
Environmental Microbiology and Microbial Ecology
Department of Food Science and Technology: Dissertations, Theses, and Student Research
Articles 1 - 5 of 5
Full-Text Articles in Entire DC Network
Dietary Fiber Utilization In The Gut: The Role Of Human Gut Microbes In The Degradation And Consumption Of Xylose-Based Carbohydrates, Elizabeth Drey
Dietary Fiber Utilization In The Gut: The Role Of Human Gut Microbes In The Degradation And Consumption Of Xylose-Based Carbohydrates, Elizabeth Drey
Department of Food Science and Technology: Dissertations, Theses, and Student Research
Xylans are a family of xylose-based polysaccharides naturally present in fruits, vegetables, and cereal grains. Resistant to digestion by host enzymes, xylans reach the large intestine intact, where they are utilized by members of the gut microbiome. They are initially hydrolyzed by primary degraders that utilize extracellular xylanases to cleave xylan into smaller oligomers. These xylooligosaccharides (XOS) can then either be further hydrolyzed by primary degraders or can cross-feed secondary consumers, including Bifidobacterium. While several Bifidobacterium species have metabolic systems for XOS, studies have shown these species grow poorly on longer XOS and xylan substrates. In this thesis, …
From Milpas To The Market: A Study On The Use Of Metal Silos For Safer And Better Storage Of Guatemalan Maize, José Rodrigo Mendoza
From Milpas To The Market: A Study On The Use Of Metal Silos For Safer And Better Storage Of Guatemalan Maize, José Rodrigo Mendoza
Department of Food Science and Technology: Dissertations, Theses, and Student Research
This project aimed to implement the use of metal silos to improve quality and safety of maize consumed by inhabitants of the highlands of Guatemala. This manuscript includes a literature review of the maize production chain in Guatemala, a survey about agricultural practices used in the region of study, as well as a characterization of the analyzed maize regarding its mycoflora, nutritional composition, and insect infestation. To better understand the current situation regarding agricultural practices and maize consumption, a survey was carried out. Sample consisted of 280 families representing 14 rural communities distributed in the townships of Todos Santos and …
Understanding The Factors Affecting Microbiological Quality Of Wheat Milled Products: From Wheat Fields To Milling Operations, Luis E. Sabillón Galeas
Understanding The Factors Affecting Microbiological Quality Of Wheat Milled Products: From Wheat Fields To Milling Operations, Luis E. Sabillón Galeas
Department of Food Science and Technology: Dissertations, Theses, and Student Research
Although regarded as a low-risk commodity, wheat flour-based mixes have been implicated in several food safety incidents. The present thesis is a compilation of five scientific manuscripts on the effect of weather variation, milling steps and implementation of pre-milling interventions on the microbiological quality and safety of wheat and milled products. The first manuscript is a review of the microbiological quality and safety of wheat-based products. Despite the low water activity, wheat flour may harbor dormant but viable microorganisms, which could lead to safety concerns when flour is used to produce refrigerated dough products. The second manuscript illustrates the effect …
The Evolution Of Host Specificity In The Vertebrate Gut Symbiont Lactobacillus Reuteri, Steven Frese
The Evolution Of Host Specificity In The Vertebrate Gut Symbiont Lactobacillus Reuteri, Steven Frese
Department of Food Science and Technology: Dissertations, Theses, and Student Research
The vertebrate gut is home to one of the densest populations of life on Earth. This microbial community has a profound effect on host health, nutrition, development, behavior, and evolution. However, very little is known about how these microbes have evolved with their vertebrate hosts, how and whether they select hosts or how they remain associated with their hosts. Recent work identified Lactobacillus reuteri as an organism that is composed of host-specific sub-populations, each population associated with a different host animal. Representatives from each host-associated population were tested for their ability to colonize gnotobiotic mice, which only rodent strains could …
Analysis Of Microbial Diversity By Amplicon Pyrosequencing, Ryan Legge
Analysis Of Microbial Diversity By Amplicon Pyrosequencing, Ryan Legge
Department of Food Science and Technology: Dissertations, Theses, and Student Research
Microorganisms numerically dominate terrestrial biodiversity, and play important biochemical and geochemical roles in the environments they inhabit. To understand structure and function of complex ecosystems, it is essential to identify primary drivers of microbial diversity and community structure. Historically, the study of microbial ecology was reductive, limited to microbes able to be cultured and enumerated. Microbes meeting this criterion were thought to comprise the dominating members of the environments they were isolated from, however, estimates suggesting up to 99% of the endogenous species are uncultivable with existing methodologies; a concept that reflects experimental failure, rather than a verifiable conclusion. Therefore …