Life Sciences Commons^™

Comparative Characteristics During Wilting For Forage Harvested By Maceration Vs. A Conventional Roller-Conditioner, Suwarno, K M. Wittenberg, W P. Mccaughey

IGC Proceedings (1993-2023)

Two studies were conducted to monitor forage nutrient and microbial changes during wilting of alfalfa (Medicago sativa L.) forage in response to varying degrees of maceration at harvest. Early bloom alfalfa forage was harvested with either a roller conditioner (Control) or a macerator, with four degrees of maceration (Light, Light plus, Moderate and Severe) imposed. Macerated forage reached an 80% dry matter 10-27 hours sooner than roller-conditioned forage, the most rapid drying rates being associated with the more severely macerated treatments. Total bacteria and lactic acid bacteria populations tended (P < 0.07 and P < 0.08, respectively) to increase with maceration. Macerated forage, when exposed to precipitation, had lower (P < 0.05) crude protein and higher (P < 0.05) fiber concentration than roller-conditioned forage. Macerated forage, exposed to 2 cm precipitation during wilting without precipitation reached 80% DM sooner than conventionally cut alfalfa exposed to no precipitation.

The Addition And Cessation Of Inorganic Fertiliser Amendments In Long-Term Managed Grasslands: Impacts On Above And Below-Ground Communities, C. D. Clegg, P. J. Murray, R. Cook, T. Tallec

IGC Proceedings (1993-2023)

In recent times, land use in the United Kingdom has undergone considerable changes because of social and economic pressures, leading to a fine balance between the demands of highly productive intensive systems and practices which are perceived to be more environmentally acceptable. Plant productivity is governed by the supply of nutrients from the soil, which in turn is dependent on the dynamics of organic matter decomposition driven by soil micro-, meso- and macro fauna. Considerable information is available concerning the impact of inorganic fertiliser additions on communities of macro-fauna and flora, but the effects on specific microbial communities in soils …

Exploring The Use Of Covellite As A Proxy For Corrosion Of Native Copper By Sulphur Reducing Bacteria, Manan K. Joshi

Undergraduate Student Research Internships Conference

We are analyzing the effect of sulphate reducing bacteria on native copper, and using that evidence to further support the initiative of having a deep geological repository to store nuclear material. Sulphate reducing bacteria are a concern for the deep geological repository as they cause the corrosion of regular copper. However native copper has gone billions of years without corrosion, which could either mean that it had not been exposed to sulphate reducing bacteria over the billions of years, or native copper is able to withstand corrosion despite the contact of sulphate reducing bacteria. We can find out by trying …

Effect Of Prompt-Delayed Packaging And Ensiling Time On Fermentation And Aerobic Stability Of Soybean Curd Residue, Ajmal Wali, Takeshi Tsuruta, Naoki Nishino

IGC Proceedings (1993-2023)

Wet soybean curd residue (SCR) obtained from two tofu factories (F1 and F2) was anaerobically stored with or without added beet pulp (BP). Sealing was performed on the day of tofu production (prompt sealing [PS]) or 2 days after SCR was piled and unprocessed (delayed sealing [DS]). Predominant lactic acid fermentation was observed regardless of the sealing time and BP addition. Acinetobacter spp. were the most abundant (> 67%) bacteria in pre-ensiled SCR, regardless of the factory and sealing time. In PS silage, the abundances of typical lactic acid-producing bacteria, such as Lactobacillus, Pediococcus, and Streptococcus spp. reached …

Soil Biodiversity, Root Herbivory And Carbon And Nitrogen Cycling In Grassland Soils, R. Cook, L. A. Dawson, A. C. Gange, S. J. Grayston, P. J. Murray, A. M. Treonis

IGC Proceedings (1993-2023)

This paper describes research on the relationships between grassland management practices and the diversity of biological communities in soil. Observations are being made in field trials with applications of nitrogen and lime and of insecticide to an original diverse sward and to a single species grass re-seed. The treatments are designed to produce different degrees of diversity in communities of soil animals and microbes. Assessments are being made over three years of the effects on the populations, activity and diversity of root-feeding animals, arbuscular mycorrhizal fungi, soil bacteria, fungi and micro fauna, including nonplant feeding nematodes. Associated laboratory experiments assess …

Translating -Omics Big Data: Comprehensive Understanding Of Host-Pathogen Interactions To Control Bacterial Blight In Alfalfa Using Computational Approaches, Raghav Kataria

Student Research Symposium

Plant infectious diseases are a major threat to the crops, owing to economic losses to the agriculture industry worldwide. Molecular interactions between the host and pathogen play a critical role in understanding the basis of pathogenesis. Majority of the Pseudomonas syringae strains are known to cause frost injury in plants, amongst which, P. syringae pv. syringae ALF3 is asserted to be a causal organism of bacterial stem blight in Medicago sativa (alfalfa). We elucidated the genome-scale host-pathogen interactions (HPIs) between alfalfa and P. syringae using two intense computational approaches: interolog (homology-based) and the domain-based method (based on 3D structure of …

The Effect Of Different Types Of Inoculants On The Characteristics Of Alfalfa, Ryegrass And Red Clover-Ryegrass-Timothy Silage, Vilma Vrotniakiene, Jonas Jatkauskas

IGC Proceedings (1993-2023)

Silage inoculants based on lactic acid bacteria (LAB) have demonstrated improvements in energy and nutrient recovery from grass and legume silages by lowering the pH and shifting the fermentation towards lactic acid production, by reducing storage losses due to spoilage and by increasing the aerobic stability during feed-out. There are different mixtures of strains currently on the market.

The present study was conducted according to the Deutsche Landwirtschafts-Gesellschaft Guidelines for the testing of silage additives in order to assess which mixtures of lactic acid bacteria would have a greater potential to improve fermentation profile of alfalfa, perennial ryegrass and red …

Reproduction And Dispersal Of Biological Soil Crust Organisms, Steven D. Warren, Larry L. St. Clair, Lloyd R. Stark, Louise A. Lewis, Nuttapon Pombubpa, Tania Kurbessoian, Jason E. Stajich, Zachary T. Aanderud

Life Sciences Faculty Research

Biological soil crusts (BSCs) consist of a diverse and highly integrated community of organisms that effectively colonize and collectively stabilize soil surfaces. BSCs vary in terms of soil chemistry and texture as well as the environmental parameters that combine to support unique combinations of organisms—including cyanobacteria dominated, lichen-dominated, and bryophyte-dominated crusts. The list of organismal groups that make up BSC communities in various and unique combinations include—free living, lichenized, and mycorrhizal fungi, chemoheterotrophic bacteria, cyanobacteria, diazotrophic bacteria and archaea, eukaryotic algae, and bryophytes. The various BSC organismal groups demonstrate several common characteristics including—desiccation and extreme temperature tolerance, production of various …

The Effect Of Root Exudate 7,4'-Dihydroxyflavone And Naringenin On Soil Bacterial Community Structure, Márton Szoboszlay, Alison White-Monsant, Luke A. Moe

Plant and Soil Sciences Faculty Publications

Our goal was to investigate how root exudate flavonoids influence the soil bacterial community structure and to identify members of the community that change their relative abundance in response to flavonoid exudation. Using a model system that approximates flavonoid exudation of Medicago sativa roots, we treated a soil with 7,4′-dihydroxyflavone and naringenin in two separate experiments using three different rates: medium (equivalent to the exudation rate of 7,4′-dihydroxyflavone from M. sativa seedlings), high (10× the medium rate), and low (0.1× the medium rate). Controls received no flavonoid. Soil samples were subjected to ATP assays and 16S rRNA gene amplicon …

Bacterial Diversity And Function Within An Epigenic Cave System And Implications For Other Limestone Cave Systems, Kathleen Merritt Brannen-Donnelly

Doctoral Dissertations

There are approximately 48,000 known cave systems in the United States of America, with caves formed in carbonate karst terrains being the most common. Epigenic systems develop from the downward flow of meteoric water through carbonate bedrock and the solutional enlargement of interconnected subsurface conduits. Despite carbonate karst aquifers being globally extensive and important drinking water sources, microbial diversity and function are poorly understood compared to other Earth environments. After several decades of research, studies have shown that microorganisms in caves affect water quality, rates of carbonate dissolution and precipitation, and ecosystem nutrition through organic matter cycling. However, limited prior …

Rare Occurrences Of Free-Living Bacteria Belonging To Sedimenticola From Subtidal Seagrass Beds Associated With The Lucinid Clam, Stewartia Floridana, Aaron M. Goemann

Masters Theses

Lucinid clams and their sulfur-oxidizing endosymbionts comprise two compartments of a three-stage, biogeochemical relationship among the clams, seagrasses, and microbial communities in marine sediments. A population of the lucinid clam, Stewartia floridana, was sampled from a subtidal seagrass bed at Bokeelia Island Seaport in Florida to test the hypotheses: (1) S. floridana, like other lucinids, are more abundant in seagrass beds than bare sediments; (2) S. floridana gill microbiomes are dominated by one bacterial operational taxonomic unit (OTU) at a sequence similarity threshold level of 97% (a common cutoff for species level taxonomy) from 16S rRNA genes; …

Reduction Of Iron (Iii) And Humic Substances Plays A Major Role In Anaerobic Respiration In An Arctic Peat Soil, David A. Lipson, Mony Jha, Ted K. Raab, Walter C. Oechel

Ted K. Raab

Arctic peat soils contain vast reserves of organic C and are largely anaerobic. However, anaerobic respiration, particularly the role of Fe(III) and humic substances as electron acceptors, is not well understood in such ecosystems. We investigated these processes in a drained thaw lake basin on the Arctic coastal plain near Barrow, Alaska. We measured concentrations of soluble Fe and other potential electron acceptors, described the microbial community, and performed experiments in the laboratory and field to measure net rates of Fe(III) reduction and the relationship of this process to C cycling. In most areas within the basin, aerobic conditions existed …

Copper Isotope Fractionation During Surface Adsorption And Intracellular Incorporation By Bacteria, Jesica Urbina Navarrete

Open Access Theses & Dissertations

Copper isotopes may prove to be a useful tool for investigating bacteria-metal interactions recorded in natural waters, soils, and rocks. However, experimental data that constrain Cu isotope fractionation in biologic systems are limited and unclear. In this study we utilized Cu isotopes (65Cu) as a tool to investigate Cu-bacteria interactions, including surface adsorption and intracellular incorporation. Experiments were conducted with individual Gram-positive (Bacillus subtilis) and Gram-negative (Escherichia coli) bacterial species as well as with bacterial consortia from several natural environments. Adsorption experiments were conducted with live or dead cells over the pH range 2.5 to 6. Surface adsorption of Cu …

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

U.S.-Korea Cooperative Research: Carbon Monoxide As A Substrate For Microbial Maintenance, Gary M. King

University of Maine Office of Research Administration: Grant Reports

Bacteria play an important role in the global budget of carbon monoxide (CO). Largely unknown bacterial populations in soils and the water column of aquatic systems oxidize hundreds of teragrams per year, or about 10%-20% of the estimated annual flux to the atmosphere. In spite of their biogeochemical significance, relatively little is known about the identity of CO-oxidizing populations active in situ, their phylogenic and physiological diversity or the importance of CO as substrate for their basic metabolic needs. of CO oxidizers. It is clear that CO at high concentrations (> 1000 ppm) can serve as a sole source of …

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 …

Microbial Growth And Biofilm Formation In Geologic Media Is Detected With Complex Conductivity Measurements, Caroline A. Davis, Estella A. Atekwana, Eliot A. Atekwana, Lee D. Slater, Silvia Rossbach, Melanie R. Mormile

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Complex conductivity measurements (0.1-1000 Hz) were obtained from biostimulated sand-packed columns to investigate the effect of microbial growth and biofilm formation on the electrical properties of porous media. Microbial growth was verified by direct microbial counts, pH measurements, and environmental scanning electron microscope imaging. Peaks in imaginary (interfacial) conductivity in the biostimulated columns were coincident with peaks in the microbial cell concentrations extracted from sands. However, the real conductivity component showed no discernible relationship to microbial cell concentration. We suggest that the observed dynamic changes in the imaginary conductivity (σ″) arise from the growth and attachment of microbial cells and …

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 …

Final Report - Lake Mead Monitoring Program, James E. Deacon

Publications (WR)

The Lake Mead monitoring program has developed a substantial body of information on the physical, chemical and biological limnology of Lake Mead since 1972. This report summarizes pertinent aspects of that data, with emphasis on studies completed in 1975 -76. It is our continuing hope that the data developed by us will be useful to an ever broader group of users of the water resource represented by Lake Mead. We have been privileged to see our data have a significant influence in some very important water resource decisions over the past four years. There is every reason to expect that …

Some Impurities In Drinking Water, George Weitbrecht

Journal of the Minnesota Academy of Science

The more we know about the causes of disease the more we are convinced that many of the ills that flesh is heir to come to us through germs that are transmitted through the air we breath, the water we drink and the food we eat. You are all familiar with the westward march of cholera among men and epizooty among animals. In surgical operations the danger is not from the operation, but from germs which are in the air and which get into the body through the wound, producing surgical fever, etc. Since Lester used the carbolic acid spray …