Digital Commons Network^™

Drought Legacy Interacts With Wildfire To Alter Soil Microbial Communities In A Mediterranean Climate-Type Forest, Anna J. M. Hopkins, Aaron J. Brace, Jess L. Bruce, J. Hyde, J. B. Fontaine, L. Walden, W. Veber, K. X. Ruthrof

Research outputs 2022 to 2026

Mediterranean forest ecosystems will be increasingly affected by hotter drought and more frequent and severe wildfire events in the future. However, little is known about the longer-term responses of these forests to multiple disturbances and the forests' capacity to maintain ecosystem function. This is particularly so for below-ground organisms, which have received less attention than those above-ground, despite their essential contributions to forest function. We investigated rhizosphere microbial communities in a resprouting Eucalyptus marginata forest, southwestern Australia, that had experienced a severe wildfire four years previously, and a hotter drought eight years previously. Our aim was to understand how microbial …

Evaluating The Enzymatic Activity Of Transformed X. Cucurbitae, Emily Beger, Iris Lee, Sarah Hind

PRECS student projects

Introduction

• The United States’ pumpkin industry exceeds one billion dollars [1], with Illinois contributing to over 90% of processing pumpkin production.
• Pumpkin growers face a rising concern due to the increasing occurrence of Xanthomonas cucurbitae , the pathogen that causes bacterial spot disease in cucurbits, including pumpkins.
• X. cucurbitae infection leads to the appearance of small, sunken, beige spots on cucurbit fruits and leaves.
• Over time, the bacterium can compromise fruit integrity by breaking down the epidermis and cuticle. • Bacterial spot disease also creates opportunities for other bacteria and fungi to infiltrate the affected fruits, leading to fruit rot …

Characterization Of Landfill Leachate For Enhanced Metal Recovery, Hanna Fulford, Amisha Shah, Inez Hua, Nadezhda Zyaykina, Lori Hoagland, Alejandro Rodriguez Sanchez, Umut Bicim

Discovery Undergraduate Interdisciplinary Research Internship

Landfills contain a trove of valuable materials, such as critical, precious, and rare earth metals, that are integral to the United State’s economy and national security. The leachate that filters through landfills picks up these materials, which allows for the possibility of recovery. For this research, samples will be analyzed from landfills throughout the Midwestern United States to provide a baseline on water quality constituents, elements present, and microbial activity. Preliminary data for this study was acquired by analyzing samples of landfill leachate from a landfill in northern Indiana. pH readings indicate that the leachate is slightly basic. It also …

Microbial Assemblages In Relation To Host And Environmental Surroundings, Mark Fischer

Senior Honors Theses

The goal of this study was to determine if the microbiome between two crayfish microhabitats were different from one other, in addition to the surrounding water and sediment. This project was a field-based study in which all environmental samples and crayfish were collected from a central Virginian freshwater stream. Molecular techniques were employed to sequence bacterial DNA from the various sample types and Qiime 2 was used to analyze statistical differences. The results from this study aligned well with the initial hypothesis in that the alpha-diversities between all of the sample types were statistically different (P<0.05) except for the gill chamber and surrounding water microbial assemblages. In addition, the Beta-diversity was statistically different when the bacterial composition of one sample type was compared to the composition of the other samples (P<0.05). This data aids in our understanding of the significance of microbes within a freshwater ecosystem and how they are distributed among freshwater organisms, such as the crayfish.

Characterization Of Microbial Populations In Landfill Leachate, Umut M. Bicim, Hanna Fulford, Lori A. Hoagland, Alejandro R. Sanchez, Amisha D. Shah, Inez Hua

Discovery Undergraduate Interdisciplinary Research Internship

In the United States, municipal solid waste (MSW) landfills remain a potential mining source of recoverable materials, including but not limited to critical, precious, and rare earth metals found in electronic waste. This is possible due to collectible leachate that filters through MSW landfills, carrying metals, nutrients of value, and microbes—some of which may hold key metal bioleaching properties—within. The purpose of this study is to begin analyzing leachate from MSW landfills in the American Midwest to understand the composition of microbial communities within these landfills. Landfill leachate samples sourced in northern Indiana, representing the landfill process during unique times …

Research Of Sustainable Jet Fuel Production Using Microbes, Rajee Olaganathan

Publications

Global climate change, coupled with rapidly increasing oil prices and energy demand around the world, has paved a way for intense research in the biofuel sector. Stakeholders in the aviation industry have started to focus on bio-jet fuel. Bio-jet fuel is regarded as a sustainable solution to greenhouse gas emissions and energy demand. This paper provides a brief review of the biofuel production technologies, the role of bacteria in producing hydrocarbons and the recent advancements in microbial engineering to enhance the biofuel production. Finally, this paper concludes by highlighting the challenges and future research implications in bio-jet fuel production.

Onshore Wind Speed Modulates Microbial Aerosols Along An Urban Waterfront, M. Elias Drucker, Gregory D. O'Mullan, Joaquín Martínez Martínez, Andrew R. Juhl, Kathleen C. Weathers

Publications and Research

Wind blowing over aquatic and terrestrial surfaces produces aerosols, which include microbial aerosols. We studied the effect of onshore wind speeds on aerosol concentrations as well as total and culturable microbial aerosols (bacterial and viral) at an urban waterfront (New York, NY, USA). We used two distinct methods to characterize microbial aerosol responses to wind speed: A culture-based exposure-plate method measuring viable bacterial deposition near-shore (CFU accumulation rate); and a culture-independent aerosol sampler-based method measuring total bacterial and viral aerosols (cells m−3 air). While ambient coarse (>2 µm) and fine (0.3–2 µm) aerosol particle number concentrations (regulated indicators of …

Summary Report Of Enhanced Monitoring And Pollution Source Tracking Efforts In The Willard Beach Watershed, Maine, 2012-2016, M. Sims, K. Kaczor

Maine Sea Grant Publications

Willard Beach is a popular recreation area located in South Portland used primarily by families with young children. Routine monitoring at the beach revealed elevated bacteria levels, prompting the need for enhanced monitoring within the watershed to determine the nature and extent of potential bacteria inputs. Although the waste of domestic and wild animals can contribute to impaired water quality and pose a public health risk, efforts have focused primarily on identifying and removing human sources (e.g. malfunctioning septic systems, faulty sewer lines) of fecal pollution.

Maine Healthy Beaches Program 2016 Annual Report To U.S. Epa, K. Kaczor, M. Sims

Maine Sea Grant Publications

Maine Healthy Beaches (MHB) is managed by the Maine Department of Environmental Protection (ME DEP) and coordinated by the University of Maine Cooperative Extension (UMaine Extension). In 2016, this team worked with 28 local management entities to conduct routine monitoring, assessment, and public notification of water quality conditions for 60 beach management areas spanning Kittery to Mount Desert Island. MHB staff continued to build local capacity for well-informed beach management and to address pollution issues when they arose during the beach season.

Summary Report Of Enhanced Monitoring And Pollution Source Tracking Efforts In Goosefare Brook, Maine, 2012-2016, M. Sims, K. Kaczor

Maine Sea Grant Publications

The Goosefare Brook (GFB) forms the border between the City of Saco to the south and Town of Old Orchard Beach (OOB) to the north. In response to concerns over water quality in the mouth and adjacent beach water, the Maine Healthy Beaches (MHB) program has supported multi-year enhanced monitoring and pollution source tracking efforts, held Stakeholder Workshops, and more to address impaired water quality throughout the watershed. Over the past five years, the MHB program has focused primarily on paired enterococci and optical brightener samples in OOB’s New Salt Rd. Tributary (NSRT). This work identified widespread bacterial contamination throughout …

2016 Goosefare Brook Mst Summary And Next Steps, M. Sims, K. Kaczor

Maine Sea Grant Publications

No abstract provided.

Jordan River Monitoring Report, Ashley Taylor, Anna Farrell

Maine Sea Grant Publications

In congruence with the Maine Department of Marine Resources’ (DMR) efforts to monitor declining water quality in the Jordan River, Frenchman Bay, Maine, the Community Lab at MDI Biological Laboratory implemented regular water quality monitoring at additional sites in the watershed to supplement the work of the DMR. Water samples were collected weekly between June and August of 2017 by staff and students from the Community Lab. Samples were collected via boat and foot to reach additional intermittent streams and smaller tributaries that feed into the Jordan River. Samples were analyzed for Enterococcus bacteria, optical brighteners, and salinity. A goal …

Plant Diseases [2016], Kimberly Leonberger, Kelly Jackson, Robbie Smith, Nicole Ward Gauthier

Agriculture and Natural Resources Publications

Anyone who has ever planted a garden knows not only the rewards of beautiful flowers, fruit, and/ or vegetables, but also the disappointment when plants become diseased or damaged. Many factors cause plants to exhibit poor vigor, changes in appearance, or even death. Both abiotic (non-living) and biotic (living) factors can negatively impact plant heath. Disorders that result from non-living factors (such as nutrient deficiencies, over/under watering, temperature stress, and chemical damage) are discussed in subsequent chapters. This chapter focuses on those living organisms that cause disease: fungi, water molds, bacteria, viruses, nematodes, phytoplasmas, and parasitic plants.

Microbial Communities Of The Providence River, Jacqueline Kratch

Honors Projects in Science and Technology

The Providence River has been industrialized for over one-hundred years. Industries such as oil storage and metal recycling facilities have left high levels of pollutant metals, including lead (Pb), in the soil and water. The elevated Pb concentrations in these environments influence the selection of Pb resistance mechanisms in the bacterial community1. One mechanism of heavy metal resistance is the Pb efflux pump, consisting of proteins in the cell membrane that aid in the transport of Pb out of the cell2. In this study we investigated the co-occurrence of Pb efflux pumps and antibiotic efflux pumps in bacteria from Pb …

Effects Of Urban Stream Burial On Organic Matter Dynamics And Reach Scale Nitrate Retention, Jake J. Beaulieu, Paul M. Mayer, Sujay S. Kaushal, Michael J. Pennino, Clay P. Arango, David A. Balz, Timothy J. Canfield, Colleen M. Elonen, Ken M. Fritz, Brian H. Hill, Hodon Ryu, Jorge W. Santo Domingo

All Faculty Scholarship for the College of the Sciences

Nitrogen (N) retention in streams is an important ecosystem service that may be affected by the widespread burial of streams in stormwater pipes in urban watersheds. We predicted that stream burial suppresses the capacity of streams to retain nitrate (NO₃ ⁻) by eliminating primary production, reducing respiration rates and organic matter availability, and increasing specific discharge. We tested these predictions by measuring whole-stream NO₃ ⁻ removal rates using ¹⁵NO₃ ⁻ isotope tracer releases in paired buried and open reaches in three streams in Cincinnati, Ohio (USA) during four seasons. Nitrate uptake lengths were 29 times …

The Effects Of Flooding On The Microbial Communities Of Sparrow Eggs In A Temperate Maine Salt Marsh, Mattie Paradise

Honors College

Microbial infection has been shown to reduce hatching success for the eggs of tropical birds. In these ecosystems, humidity and temperature encourage bacterial growth and the transport of microbes through the pores of the egg shell. A single study in a temperate ecosystem found no noticeable change of microbial communities during the length of the incubation cycle, and thus no increased risk of microbial infection by the time of hatching. This study, however, took place in the arid Mediterranean type climate of California, a locale that likely diminishes the abilities of microbial communities to colonize and grow on egg surfaces. …

Biochemical, Nutrient And Inhibitory Characteristics Of Streptomyces Cultured From A Hypersaline Estuary, The Laguna Madre (Texas), Luis E. Espinoza, Anita L. Davelos Baines, Kristine L. Lowe

Biology Faculty Publications and Presentations

Streptomyces are common soil bacteria that produce secondary metabolites, including several antibiotics; however, the characteristics of marine Streptomyces are largely unknown. Sediment samples were taken from 3 sites in the Laguna Madre to isolate marine Streptomyces. Sediment was diluted, spread onto synthetic seawater media to estimate the total bacterial density of the samples and spread onto starch casein agar to isolate Streptomyces. Isolated Streptomyces were tested for salinity tolerance and optimal growth pH. Isolates were assayed using API 20E® test strips and BIOLOG™ plates to construct biochemical profiles and assess nutrient utilization abilities of the bacteria, respectively. Individual Streptomyces were …

The Role Of Attached And Free-Living Bacteria In Biodegradation In Karst Aquifers, Roger Painter, Tom Byl, Lonnie Sharpe, Ahmad Kheder, Justin Harris

Civil and Architectural Engineering Faculty Research

Natural attenuation of groundwater contamination occurs at some level for all aquifers impacted with organic contaminants. The issues regarding natural attenuation are whether it takes place at a sufficient rate to be protective of human health and the environment. Implementation of a Monitored Natural Attenuation (MNA) remedial alternative for groundwater requires parties responsible for the contamination to demonstrate to regulators and the public that MNA is protective at a given site. Analysis of MNA for remediation of karst aquifers is hampered by a lack of understanding of biodegradation in karst environments. The lack of studies examining biodegradation in karst aquifers …

Plant Diseases, Jay W. Pscheidt, John R. Hartman

Agriculture and Natural Resources Publications

Every gardener has put in plants with hopes for wonderful flowers, fruits, or vegetables, only to have those hopes dashed as the plants get sick and die. Plants that die are considered diseased. Many things can cause plants to become diseased, including living agents, other factors (nonliving), or a combination of the two. This chapter focuses only on living agents—fungi, bacteria, viruses, nematodes, and parasitic plants. Nonliving factors, such as nutrient deficiencies, lack of water, temperature stress, and these problems in combination as they relate to specific types of plants, are discussed elsewhere.

Cellulose- And Xylan-Degrading Thermophilic Anaerobic Bacteria From Biocompost, M. V. Sizova, J. A. Izquierdo, N. S. Panikov, L. R. Lynd

Dartmouth Scholarship

Nine thermophilic cellulolytic clostridial isolates and four other noncellulolytic bacterial isolates were isolated from self-heated biocompost via preliminary enrichment culture on microcrystalline cellulose. All cellulolytic isolates grew vigorously on cellulose, with the formation of either ethanol and acetate or acetate and formate as principal fermentation products as well as lactate and glycerol as minor products. In addition, two out of nine cellulolytic strains were able to utilize xylan and pretreated wood with roughly the same efficiency as for cellulose. The major products of xylan fermentation were acetate and formate, with minor contributions of lactate and ethanol. Phylogenetic analyses of 16S …

Slides: The Use Of Terrestrial Cyanobacteria For The Rehabilitation Of Arid Soils: Not Just Another Good Idea, Timothy Flynn

Best Practices for Community and Environmental Protection (October 14)

Presenter: Dr. Timothy Flynn, Primordial Solutions Inc.

42 slides

Fish Nutrient Cycling, Aquatic Respiration, And Terrestrial Insect Nutrient Subsidies To Lakes, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

Mehner et al. (2005) reported that fish feeding on terrestrial insects could be important for nutrient budgets and cycling in lakes. They studied bleak (Alburnus alburnus) that fed largely on terrestrial insects, and they suggested that this contributed 2.1% of the lake's nutrient budget and that the subsequent excretion by the fish was equivalent to 11% of epilimnetic dissolved phosphorus concentrations. They concluded that nutrients delivered to lakes via terrestrial insects and recycled by fish would be most important for small lakes because of the large perimeter-to-area ratio between donor and recipient habitats. Fish may have important impacts …

Environmental Controls On The Landscape-Scale Biogeography Of Stream Bacterial Communities, Noah Fierer, Jennifer L. Morse, Sean T. Berthrong, Emily S. Bernhardt, Robert B. Jackson

Environmental Science and Management Faculty Publications and Presentations

We determined the biogeographical distributions of stream bacteria and the biogeochemical factors that best explained heterogeneity for 23 locations within the Hubbard Brook watershed, a 3000-ha forested watershed in New Hampshire, USA. Our goal was to assess the factor, or set of factors, responsible for generating the biogeographical patterns exhibited by microorganisms at the landscape scale. We used DNA fingerprinting to characterize bacteria inhabiting fine benthic organic matter (FBOM) because of their important influence on stream nutrient dynamics. Across the watershed, streams of similar pH had similar FBOM bacterial communities. Streamwater pH was the single variable most strongly correlated with …

Comparison Of Individual And Pooled Sampling Methods For Detecting Bacterial Pathogens Of Fish, Sonia Mumford, Chris Patterson, Joy Evered, Ray Brunson, Jay Levine, Jim Winton

United States Geological Survey: Staff Publications

Examination of finfish populations for viral and bacterial pathogens is an important component of fish disease control programs worldwide. Two methods are commonly used for collecting tissue samples for bacteriological culture, the currently accepted standards for detection of bacterial fish pathogens. The method specified in the Office International des Epizooties Manual of Diagnostic Tests for Aquatic Animals permits combining renal and splenic tissues from as many as 5 fish into pooled samples. The American Fisheries Society (AFS) Blue Book/US Fish and Wildlife Service (USFWS) Inspection Manual specifies the use of a bacteriological loop for collecting samples from the kidney of …

Light Dependence Of Selenium Uptake By Phytoplankton And Implications For Predicting Selenium Incorporation Into Food Webs, Stephen B. Baines, Nicholas S. Fisher, Martina A. Doblin, Gregory A. Cutter, Lynda S. Cutter, Brian Cole

OES Faculty Publications

The potentially toxic element selenium is first concentrated from solution to a large but highly variable degree by algae and bacteria before being passed on to consumers. The large loads of abiotic and detrital suspended particles often present in rivers and estuaries may obscure spatial and temporal patterns in Se concentrations at the base of the food web. We used radiotracers to estimate uptake of both selenite (Se(IV)) and C by intact plankton communities at two sites in the Sacramento/San Joaquin River Delta. Our goals were to determine (1) whether C and Se(IV) uptake were coupled, (2) the role of …

Bacteriological Water Quality Of Forested And Pastured Streams Receiving Land-Applied Poultry Litter, Matthew W. Mcbroom, Chang Mingteh, Charles Wells

Faculty Publications

Poultry production is a growing industry in East Texas, generating about 360,000 m tons of broiler litter each year as a by-product for application on pasturelands. Grab samples of fecal coliform (FC) and fecal streptococcus (FS) were collected monthly between March and December 1996 and FC and E-coli samples were collected weekly between July and October 2001 at six sites on the Waffelo and Terrapin Creeks in Nacogdoches County, Texas to assess possible impacts of poultry litter application on bacterial water quality. Sites were grouped by three pairs with each pair consisting of one upstream site in predominantly forested area …

A Review Of Pathogens Of Agricultural And Human Health Interest Found In Canada Geese, Larry Clark

United States Department of Agriculture Wildlife Services: Staff Publications

The roles that waterfowl in general, and Canada geese in particular, have in the dissemination and transmission of viral and bacterial diseases of human or agricultural importance are covered in this review. In addition to the biological information about the etiology of the disease, economic impacts and zoonotic potential of viral and bacterial pathogens are considered. In most cases existing evidence suggests the importance of waterfowl in disease dissemination and transmission, however, definitive data are often lacking, indicating the need for more directed studies before quantitative risk assessments can be made. Finally, a brief assessment of management options is considered.

Importance Of Bacterial Decomposition And Carrion Substrate To Foraging Brown Treesnakes, S.M. Jojola-Elverum, J.A. Shivik, L. Clark

United States Department of Agriculture Wildlife Services: Staff Publications

Brown treesnakes are an invasive species to the island of Guam that have caused extensive ecological and economic damage. Efforts to control the snake population have included trapping using live mouse lures, but for logistical and economic reasons a synthetic lure is needed. When searching for live food, brown treesnakes use both visual and odor cues. However, when searching for carrion, odor cues are sufficient. Attempts to develop synthetic lures based on chemical reconstruction of the complex carrion odor have not succeeded. We provide evidence that a microbial–substrate interaction is important for bait take by brown treesnakes. Microbial cultures taken …

Metal-Resistance Genetically Engineered Bacteria, Sylvia Daunert, Donna Scott, Sridhar Ramanathan

KWRRI Research Reports

Bacterial-based electrochemical and optical sensing systems that respond in a highly selective and sensitive manner to antimonite and arsenite have been developed. This was accomplished by using genetically engineered bacteria bearing one of two plasmids constructed for our studies. The first plasmid, pBGD23, contains the operator/promoter region (O/P) and the gene of the ArsR protein from the ars operon upstream from the β-galactosidase gene. In the absence of antimonite/arsenite, ArsR binds to the 0/P site and prevents the transcription of the genes for ArsR and β-galactosidase, thus blocking expression of these proteins. When antimonite or arsenite is present in the …

Development And Lipid Composition Of The Harpacticoid Copepod Nitocra Spinipes Reared On Different Diets, Gregory M. Weiss, George B. Mcmanus, H. Rodger Harvey

OES Faculty Publications

We reared the harpacticoid copepod Nitocra spinipes on diets of bacteria, a diatom, or a macroalga, evaluating survivorship and growth in short-term (≤ 1 generation) experiments. Lipid content of the copepods and their diets was measured and used as an index of nutrition. Although growth, survivorship and lipid content of N. spinipes were significantly greater when fed the diatom, which had the highest lipid content of the 3 diets, the copepod was able to develop from egg to adult when fed a lipid- poor bacterial diet. Furthermore, this species was able to go through developmental molts without the addition of …