University of Idaho
“Microbial Metabolomics: From Manure to Bioplastics”
My research aims to characterize metabolomes within undefined mixed microbial consortia (MMC) to better understand what factors inhibit and/or enhance efficient conversion of volatile fatty acids (VFAs) into polyhydroxyalkanoate (PHA), a compound used in biodegradable plastics. I apply Liquid chromatography–mass spectrometry (LC/MS) metabolomics methods to uncover “feast” PHA metabolisms of MMC cultured on fermented dairy manure; “feast” metabolisms induced under aerobic dynamic feeding (ADF) remain poorly understood, with only limited molecular-level exploration.
These results will enhance understanding of MMC cultured on real wastewaters, MMC metabolome dynamics when synthesizing PHAs, better describe feast-famine response, and identify critical metabolites involved in PHA synthesis. Producing bioplastics from dairy manure utilizing MMC can provide a sustainable solution to help alleviate environmental challenges associated with manure nutrient runoff, and curb petroleum-based plastics pollution.
Maribel Alfaro is a student in Civil & Environmental Engineering studying under Dr. Erik Coats.
Boise State University
“Agricultural Workplace Compliance with the Environmental Protection Agency’s Worker Protection Standard: An Idaho Analysis ”
Farmworkers are at a high risk for occupational pesticide exposure and pesticide-related illness. The Environmental Protection Agency’s Worker Protection Standard (WPS) is the primary set of federal regulations aimed at reducing pesticide exposure among farmworkers, but available data is limited regarding the extent to which agricultural employers comply with the WPS.
The Idaho State Department of Agriculture (ISDA) is responsible for conducting WPS compliance inspections in Idaho, during which ISDA staff indicate whether an agricultural employer is in compliance with each component of the WPS.
We analyze and describe the results of 832 WPS compliance inspections conducted by the ISDA at agricultural establishments (farms, forests, nurseries, and greenhouses) between 2001-2019. In particular, we describe spatial and temporal compliance trends and those components of the WPS with which agricultural employers were least compliant.
Rachel Phinney is a master's student in Health Sciences studying under Dr. Cynnie Curl.
Boise State University
“Phantom Rivers: How Wildlife Respond to a Landscape-Scale Noise Playback Experiment”
The effects of human-made noise (e.g. traffic noise) on wildlife are thought to be widespread and negative. However, we know next to nothing about the evolutionary context of this disturbance. While human-made noise is a relatively new disturbance, animals have evolved in naturally noisy areas since the origins of hearing organs, making it likely to be an important niche axis that structures animal communities. Many birds, bats, and insects use sound to find mates, avoid predators, and find prey – thus are likely to be affected by river noise in various ways. I outline a multi-year, large-scale, noise playback experiment in the Rocky Mountains of Idaho aimed at understanding how natural sources of whitewater river noise affect these animal communities, and the interactions between predator and prey.
Dylan Gomes is a doctoral student in Ecology, Evolution and Behavior studying under Dr. Jesse Barber.
Averi L. McFarland
Idaho State University
“Manganese influences production of protective capsule in Pneumonia causing bacteria”
Many pathogenic bacteria, including the major upper respiratory pathogen Streptococcus pneumoniae, produce a protective capsular polysaccharide (CPS) essential for virulence. During initial colonization of S. pneumoniae, the CPS must be thin enough to allow adherence to mammalian host cells. As the bacteria progresses into the lungs and invades the circulatory system, the CPS must be thick enough to resist host defenses such as phagocytosis.
To date, the regulatory mechanism of CPS production is unclear. Given the need for pneumococcus to modulate CPS expression in various host niches, it has been postulated that environmental factors such as nutrient availability including metal ions may influence this regulation. We hypothesize that intracellular Mn homeostasis plays a critical role in modulating CPS production via activation of key Mn-requiring enzymes, such as the regulatory phosphotyrosine phosphatase CpsB and/or the phosphoglucomutase Pgm whose reaction provides a precursor sugar for CPS formation.
Our results show that increases in intracellular manganese (Mn) concentrations boost CPS production in S. pneumoniae, whereas Mn-limitation generates the opposite effect. Using a metal-free mag-fura-2 competition assay, we show that both apo-CpsB and apo-Pgm proteins can bind up to two Mn2+ ions, with the second binding event possibly dictating activation of the enzyme. Furthermore, we demonstrate that hyperactivation of CpsB during Mn-stress does not promote aberrant dephosphorylation of the kinase CpsD suggesting that other factors are involved in regulating CPS production. Additional studies show that Mn2+ enhances Pgm specific activity, but not other divalent metal cations tested. These results suggest a role for Mn homeostasis in the regulation of CPS biogenesis via hyperactivation of Pgm by Mn2+ thereby increasing sugar flux through the capsule biosynthesis pathway to increase capsule thickness. This reveals yet another important aspect for S. pneumoniae to maintain optimal intracellular Mn concentrations.
Averi McFarland is a student from Rexburg, ID in Microbiology studying under Dr. Julia Martin.