Environmental Microbiology and Microbial Ecology Commons^™

Optimisation Of Biomass And Lipid Production Of A Tropical Thraustochytrid Aurantiochytrium Sp. Umacc-T023 In Submerged-Liquid Fermentation For Large-Scale Biodiesel Production, Sohedein Mohamad Nor Azzimi

Student Works (2020-2029)

A tropical thraustochytrid, Aurantiochytrium sp. UMACC-T023, was optimised for high biomass and lipid production in submerged-liquid fermentation (SLF). Biomass and lipid production were optimised based on glucose, polypeptone, and yeast extract concentration using response surface methodology (RSM). In RSM, the applied central composite design (CCD) showed that the optimisation model was significant for all variables studied. Yeast extract and polypeptone were associated with significant effects in UMACC-T023 biomass production with p < 0.05. The model was validated by employing the optimised media composition in shake flasks and in 1.4-L stirred-tank bioreactors. The optimised media composition for both biomass and lipid production was 10 g L-1 glucose, 15.08 g L-1 polypeptone, and 13.56 g L-1 yeast extract. Biomass production in the bioreactor increased 2.12-fold compared with the shake flask culture utilising the same optimised media composition. This result demonstrated that the optimized media composition can be utilised for large-scale lipid production of UMACC-T023 for potential biodiesel feedstock as it also fulfilled the international standards for biodiesel.

Meeting Report Of The Third Annual Tri-Service Microbiome Consortium Symposium, J Philip Karl, Robyn A. Barbato, Laurel A. Doherty, Aarti Gautam, Sarah M. Glaven, Robert J. Kokoska, Dagmar Leary, Rebecca Mickol, Matthew A. Perisin, Andrew J. Hoisington, Edward J. Van Opstal, Vanessa Varaljay, Nancy Kelley-Loughnane, Camilla A. Mauzy, Michael S. Goodson, Jason W. Soares

Faculty Publications

The Tri-Service Microbiome Consortium (TSMC) was founded to enhance collaboration, coordination, and communication of microbiome research among U.S. Department of Defense (DoD) organizations and to facilitate resource, material and information sharing among consortium members. The 2019 annual symposium was held 22–24 October 2019 at Wright-Patterson Air Force Base in Dayton, OH. Presentations and discussions centered on microbiome-related topics within five broad thematic areas: 1) human microbiomes; 2) transitioning products into Warfighter solutions; 3) environmental microbiomes; 4) engineering microbiomes; and 5) microbiome simulation and characterization. Collectively, the symposium provided an update on the scope of current DoD microbiome research efforts, highlighted …

Metabolic Network Analysis Of Filamentous Cyanobacteria, Daniel Alexis Norena-Caro

LSU Doctoral Dissertations

Cyanobacteria were the first organisms to use oxygenic photosynthesis, converting CO₂ into useful organic chemicals. However, the chemical industry has historically relied on fossil raw materials to produce organic precursors, which has contributed to global warming. Thus, cyanobacteria have emerged as sustainable stakeholders for biotechnological production. The filamentous cyanobacterium Anabaena sp. UTEX 2576 can metabolize multiple sources of Nitrogen and was studied as a platform for biotechnological production of high-value chemicals (i.e., pigments, antioxidants, vitamins and secondary metabolites). From a Chemical engineering perspective, the biomass generation in this organism was thoroughly studied by interpreting the cell as a microbial …

Analysis Of Biofilm Remediation Capacity For Octenyl Succinic Anhydride (Osa), A Bioactive Food Starch Modifier Compound, Matthew R. Borglin

Master's Theses

Matthew R. Borglin

This thesis demonstrates efficacy of Octenyl Succinic Anhydride (OSA), as a biofilm sanitizer. Biofilms allow bacteria to adhere to solid surfaces with the use of excreted polymeric compounds. For example, surfaces found in food production or processing facilities such as the interior of a raw milk holding tank, are some of the most susceptible to biofilm contamination. When present, biofilms can cause a variety of negative effects, which include; reduction of product shelf life, corrosion, and outbreaks of foodborne illnesses. The close association of biofilms with the majority of foodborne illness cases led the US Environmental Protection …

Isolation Of Plastic-Degrading Fungi From Landfill And Determining The Selected Plastics Biodegradation Capability, Mohan Priya

Student Works (2020-2029)

Polyethylene Terephthalate (PET), Low Density Polyethylene (LDPE) and High Density Polyethylene (HDPE) are the most important polymers used predominantly in present world. Since synthetic polymers hardly undergo degradation and remain in the environment for a very long time, up to 1000 years, these drawbacks increase the percentage of solid wastes in landfill and threaten the environment. To date, Municipal Solid Waste (MSW) landfill is the most favored disposal method especially among the developing countries. The aim of present study is to evaluate the potential of fungus isolated from landfilled plastics to degrade PET, LDPE and HDPE. Besides, effect of different …

Polyhydroxyalkanoates For Innovative Electrodes And Proton Exchange Membrane Modification In Microbial Fuel Cell, Abdul Azeez Olayiwola Sirajudeen

Student Works (2020-2029)

The increase in global energy demand due to increasing population and industrialization demands renewable and environmental-friendly alternatives. Energy from fossil fuel are non-renewable, depleting and detrimental from environmental perspectives. Alternative energy, green and renewable such as hydrogen fuel, biodiesel, bioethanol, microbial fuel cell and many more have been extensively investigated. One possible solution lies with non-combustion method such as microbial fuel cell. A microbial fuel cell is a sustainable and environmental-friendly device that combines electricity generation and wastewater treatment through metabolic activities of microorganisms. However, low power output from inadequate electron transfer to the anode electrode hampers its practical implementation. …

Abundance And Distribution Of Microplastics And Phthalic Acid Esters In Selected Mangrove Areas In Peninsular Malaysia, Anuar Norkhairah

Student Works (2020-2029)

Contamination of microplastics in mangrove has been receiving growing attention as experts reckon 30 billion tonnes of plastics will accumulate in 2050. The vast increase in plastic commodities will increase microplastics abundance in mangroves as mangroves are substantially sinks and traps for plastic debris. Due to persistent properties and high surface to volume ratio of microplastics, Phthalic Acid Esters (PAEs) can be taken up by microplastics, representing a grave threat to the ecosystems. This study investigated the abundance and distribution of microplastics and PAEs in selected mangrove areas in Peninsular Malaysia. The objectives of this study are to identify the …

Analysis And Exploration Of Novel Antibiotic-Producing Streptomyces Spp. In Spokane County, Washington, Kyle S. Kramer, Jenifer B. Walke Ph.D

2020 Symposium Posters

According to the Centers for Disease Control and Prevention, a US citizen is infected by an antibiotic-resistant pathogen every 11 seconds, and every 15 minutes, a patient dies as a result of these infections. Due to the increasing incidence of antibiotic-resistant pathogenic microbes, the study and exploration of novel antibiotics from novel environments are imperative as infectious diseases are the second leading cause of death in the United States. The purpose of this research is to investigate and analyze antibiotic-producing soil microbes in Spokane County, WA, with hopes of discovering novel antibiotic-producing microbes, specifically Streptomyces species, and explore some of …

Mathematical Modeling Of Gliding Motility And Its Regulation In Myxococcus Xanthus, Yirui Chen

Biology and Medicine Through Mathematics Conference

No abstract provided.

The Trichoplusia Ni Gut Microbiome And Its Derivation From The Phyllosphere Of Its Food Plants, Josemaria Garcia, Marisol Escanuela, Swapna Bhat, Evan Lampert

Georgia Journal of Science

Insects are the most abundant and diverse animals on planet Earth and rely on their diverse microbiomes to be so. The insect gut microbiome is vital in the growth and development of many insect species. Trichoplusia ni, the cabbage looper, is a generalist herbivore, but little is known about its microbiome. In this study, a metagenomic analysis of fecal samples was used to determine the effect of diet on the microbiome of T. ni larvae. Larvae were reared on six plant species, the microbiome was sampled from fecal material, and the phyllosphere was sampled from leaves the larvae ate. …

The Physiology And Evolution Of Selenite Respiration In Bacteria, Michael Wells

Electronic Theses and Dissertations

The selenium oxyanions selenate (Se(VI)) and selenite (Se(IV)) can be utilized by some bacteria and archaea as terminal electron acceptors in anaerobic respiration. Se(VI) and Se(IV) respiration is mediated by a phylogenetically and ecologically diverse array of organisms, suggesting that selenium respiration is ubiquitous in natural environments. Several respiratory Se(VI) reductases have been characterized in bacteria, revealing that Se(VI) respiration has evolved independently several times in this domain. Se(IV) respiration, in contrast, has yet to be characterized. I have purified and characterized the first respiratory Se(IV) reductase from Bacillus selenitireducens MLS10. The Se(IV) reductase appeared to purify as a single …

Effects Of Warming On Decomposition Of Submerged Plant Litter And Associated Microorganisms In Streamside Channels, Kaity Ackerman

Electronic Theses and Dissertations

Surface air temperatures are predicted to increase in the near future, which will likely affect microbial activity and carbon flow in stream ecosystems. I performed an experiment in streamside channels at Coweeta Hydrological Laboratory, NC to assess responses of litter-associated microorganisms to moderate increases in water temperature (5 levels, ambient to +4°C). The objectives of the experiment were to determine: (1) if there are differences in the magnitude of responses to temperature among various microbial parameters and (2) whether microbial responses to temperature vary among plant litter of different carbon quality. Thus, I measured litter decomposition rate, fungal biomass (ergosterol), …

Possible Role Of N-Acetylglucosamine For Induction Of Polyhydroxybutyrate Depolymerase In Streptomyces Sp. Sfb5a, Morgan Todd

Honors Projects

Streptomyces sp. SFB5A is a filamentous, Gram-positive bacterium that makes a polyhydroxybutyrate (PHB) depolymerase to degrade PHB for energy usage. Its life cycle begins as spores germinate to form vegetative mycelia. Starvation prompts formation of aerial mycelia and ultimately spores after 5-7 days. During starvation, Streptomyces may use peptidoglycan hydrolases to degrade its own cell walls, releasing N-Acetylglucosamine (NAG). PHA depolymerase activity is detected during growth of strain SFB5A on NAG as the sole carbon source, suggesting that NAG induces PHA depolymerase synthesis. To test this hypothesis, strain SFB5A was grown for 4 days on PHB, and a colorimetric assay …

Glycogen Accumulation By Wild Type And Bald Mutant Strains Of Streptomyces Sp. Sfb5a During Growth On 3-Hydroxybutyrate, Mackenzie Francis

Honors Projects

Previous research has shown that Streptomyces sp. SFB5A produces PHA depolymerase and forms aerial hyphae, while the bld4 mutant of this species forms aerial hyphae very poorly and does not produce PHA depolymerase. This effect may be due to the mutant’s inability to sense starvation. Therefore, we hypothesized that the bld4 may also be deficient in formation of glycogen and spores, which are both associated with starvation. To test this hypothesis, we grew the wild type (WT) Streptomyces sp. SFB5A and bld4 in broth cultures containing 3HB. We compared 3HB consumption, glycogen accumulation, PHA depolymerase synthesis, protein accumulation, and spore …

The Release, Transport, And Utilization Of Phosphorus From Bed-Sediments: A Study Of A Eutrophic Littoral Cove On Beaver Lake In Northwest Arkansas, James A. Mccarty

Graduate Theses and Dissertations

Eutrophication of surface waters not only impacts the environment but also water treatment processes, the most significant of which is from the effects of algae. During peak algal growth in many southern U.S. reservoirs, inflows that bring nutrients are at an annual minimum, and phosphorus released from bed-sediments is trapped in the hypolimnion. Littoral areas, described as the most productive zone of the lake, may be a possible source of phosphorus that fuels algal growth in the reservoir. I studied an isolated shallow cove in the War Eagle Creek arm of Beaver Lake in Northwest Arkansas to measure, quantify, and …

Effects Of Light, Nutrients, And Salts On Microbial Biofilm Productivity And Detrital Processing In Aquatic Mesocosms, Bethanie Brooke Howard-Parker

Graduate Theses and Dissertations

Anthropogenic activities associated with urbanization, agriculture, and resource extraction continue to increase to support increasing needs of the growing population. These activities increase the amounts of pollutants entering freshwater streams and put aquatic ecosystems at structural and functional risk. Aquatic microbes play an important role in detrital processing in streams as a key linkage in moving carbon from detrital stocks into aquatic food webs. My research investigates the effects of light, nutrients, and salts on detrital microbes and decomposition in freshwaters using a mesocosm approach. In chapter one, I modified a current priming effect (PE) hypothesis model to include light …

A Comparative Taxonomic And Diversity Study Of Litter-Associated Fungi In Northwest Arkansas Forests, Rajaa Abdulrazzaq Abbas Al Aanbagi

Graduate Theses and Dissertations

Fungi are taxonomically the most species-rich group of organisms on the earth, ecologically occupy distinctive niches and interact with diverse other organisms throughout their biogeographic distributions and functionally play key roles through their various lifestyles. Plant litter, in particular, is a keystone component in ecosystems and provides heterogeneous microhabitats for the often overlooked litter-decomposing fungi and other organisms on the floor of temperate deciduous forests. Litter fungi involve indirect interactions with the plant, soil and whole food web network. However, the community structure and functions of litter-associated fungi as well as patterns of species richness distributed across various litter microhabitats …

Elucidating The Molecular Pathways Involved In The Fitness And Water Stress Response Of Pseudomonas Synxantha 2-79 In The Plant Rhizosphere, Clint Henry D. Pablo

Master's Theses

Pseudomonas synxantha 2-79 is a biocontrol agent that represents beneficial indigenous rhizobacteria that are broadly distributed in the Pacific Northwest, USA and flourish in the rhizosphere of commercially grown wheat under surprisingly arid conditions. The molecular adaptation of 2-79-like bacteria to plants growing in dry soils is poorly understood. We hypothesized that the ability of 2-79 to colonize and persist in the rhizosphere of water-stressed plants is underpinned by the formation of hydrating biofilms and the utilization of root exudates that contain plant-derived osmoprotectants called quaternary ammonium compounds (QACs). We tested this hypothesis by identifying waters stress response pathways in …

The Effects Of Light On The Bacterial Biomass Of Decomposing Leaf Litter In Freshwater, Savannah L. Underwood

Honors Theses

Recent evidence has suggested that the presence of light (and in conjuction, periphytic algae) stimulates the growth and production of bacteria on decaying plant litter. However, the current method of measuring bacterial biomass, flow cytometry, drastically underestimates the bacterial biomass levels associated with litter samples. To determine and correct for this underestimation, the present study determined conversion factors using direct counting methods via epifluorescence microscopy. These conversion factors were then applied to flow cytometry counts for seven different studies. The studies analyzed the effects of light and other covarying factors on the bacterial biomass associated with various samples of leaf …

Soil Microbial Diversity And Litter Decomposition Increase With Time Since Land Use Disturbance In Tropical Montane Forests Of Malaysian Borneo, Renee Sniegocki

Graduate Theses and Dissertations

Logging and forest conversion are occurring at alarming rates in the tropical forests of Southeast Asia. These disturbances alter soil chemistry, microbial diversity, and disrupt carbon cycling through shifts in litter decomposition. Direct links between microbial diversity and soil properties such as pH are well established; however, the indirect impacts of logging and forest conversion on microbial diversity and litter decomposition are poorly understood. We used surface (5 cm) soil to assess soil physicochemical properties, next-generation DNA sequencing to assess soil microbial diversity, and standardized litterbags to assess litter decomposition stabilization at five sites along a land use disturbance gradient …

Identification And Analysis Of Feather Degrading Bacteria: A Search For Keratinase Genes, Nehal Navali

Honors Scholar Theses

Over two million tons of feather waste is generated annually by the poultry industry, the majority of which goes into landfills due to the difficulty of degrading its major component keratin. Although a portion of feather waste is eliminated via incineration or chemical treatment, the use of Feather Degrading Bacteria (FDB) has been proposed as a cheap and eco-friendly alternative. FDBs have been consistently isolated from the feather microbiome of birds and contain genes coding for the specialized protein keratinase which is able to degrade feathers. By doing so, feather waste, which is rich in nutrients, can be repurposed as …

Antibiotic Resistant Bacteria, Antibiotic Resistance Genes And Potential Drivers In The Aquatic Environments, Shuo Shen

Dissertations

As antibiotic resistance genes in aquatic environment have been increasing across the world, affecting water quality and public health, many studies documented concentrations of antibiotic resistance genes and some studies discussed their potential drivers. However, systematic and quantitative reviews that link antibiotic resistance genes (ARGs) to anthropogenic and environmental factors are limited. Nevertheless, this information will be important for developing regulation policy on controlling antibiotic use and therefore reducing potential risks to antibiotic resistance. I conducted meta-analysis of ARGs concentration at a global scale using Bayesian inference to explore climatic and socio-economic factors as drivers. I found local-scale climatic variables …

Comparison Of Three Analytical Techniques For General Characterisation Of Selected Algae And Cyanobacteria, Mohamed Iqbal Suhaina Nashath

Student Works (2020-2029)

Algae and cyanobacteria maintain the oxygenation of earth, and are utilised as biofuels, biofertilizers and nutrition feed. The characterisation of algae and cyanobacteria through conventional methods require technical expertise, laborious sample preparation, and moderately expensive instruments and reagents. Hence, in this study, selected bioanalytical techniques with minimal sample preparation were incorporated, to simplify the characterisation of algae and cyanobacteria. The objectives of this research were to study the phylogenetic relationship of the selected algae and cyanobacteria via the 23S plastid ribosomal ribonucleic acid (rRNA) and 18S rRNA biomarkers; to validate the presence of the microcystin synthetase (mcy) gene cluster encoding …

Effect Of Zinc On Microcystis Aeruginosa And Its Toxin Production, Jose L. Perez

Seton Hall University Dissertations and Theses (ETDs)

Cyanobacteria harmful algal blooms (CHABs) are globally increasing biomasses of detrimental cyanobacteria due to anthropogenic water phosphorous and nitrogen loading and climate change. CHABs often produce secondary metabolites, cyanotoxins, that cause harmful effects to organisms, most water systems, and socioeconomic infrastructures. Additionally, the presence of heavy metal pollutant runoff in CHAB affected environments may result in CHAB population changes – aggravating toxigenicity. Zinc metal resistance and stress response were studied in microcystin (MC) cyanotoxin-producing Microcystis aeruginosa UTEX LB 2385 (M. aeruginosa UTEX LB 2385) and non-MC producing Microcystis aeruginosa UTEX LB 2386 (M. aeruginosa UTEX LB 2386) cyanobacteria. Molecular analysis …

Investigation Of An Elevational Gradient Reveals Strong Differences Between Bacterial And Eukaryotic Communities Coinhabiting Nepenthes Phytotelmata, Kadeem J. Gilbert, Leonora S. Bittleston, Mark Arcebal K. Naive, Anthony E. Kiszewski, Perry Archival C. Buenavente, David J. Lohman, Naomi E. Pierce

Publications and Research

Elevation is an important determinant of ecological community composition. It integrates several abiotic features and leads to strong, repeatable patterns of community structure, including changes in the abundance and richness of numerous taxa. However, the influence of elevational gradients on microbes is understudied relative to plants and animals. To compare the influence of elevation on multiple taxa simultaneously, we sampled phytotelm communities within a tropical pitcher plant (Nepenthes mindanaoensis) along a gradient from 400 to 1200 m a.s.l. We use a combination of metabarcoding and physical counts to assess diversity and richness of bacteria, micro-eukaryotes, and arthropods, and compare the …

Microbiota Accessible Carbohydrates And Susceptibility To Clostridioides Difficile Infection, Keegan Schuchart, Jennifer Auchtung, Thomas Auchtung

UCARE: Research Products

This experiment looked into the effects of dietary microbiota accessible carbohydrates (MACs)on the composition of human GI microbe colonies and their susceptibility to pathogen infection. Three different concentrations of MAC ingrained media were tested in mini bioreactor arrays, treated with antibiotics, infected with Clostridioides difficile, then allowed to recover. Microbe community was examined for strain composition and diversity before and after the antibiotic treatment and Clostridioides difficile infection. After the initial mini bioreactor run, individual isolates were investigated in their ability to respond to specific MACs Arabinoglactina, Inulin, and Soluble starch at experimental concentrations.

Diatom Voucher Flora And Comparison Of Collection Methods For Biodiversity Hotspot Upper Three Runs Creek, Katie M. Johnson

Biology Theses

Surface freshwater is a scarce resource. Due to the scarcity and necessity of this resource, it is imperative that its quality is routinely monitored. One way of monitoring water quality is through biological assessments, which include examining algal assemblages. Regionally, little remains known of algal taxa in the southeastern United States. In the past, the Academy of Natural Sciences of Philadelphia (ANSP) conducted biological assessments along the Savannah River finding Gomphonema parvulum (Kützing) Kützing 1849 to be a dominant taxon rendering assessments inconclusive. Recent studies have provided evidence that species complexes and semi-cryptic taxa have been identified within the Gomphonema …

Quantifying Nutrient Throughput And Dom Production By Algae In Continuous Culture, Anne Willem Omta

Faculty Scholarship

Freshwater and marine algae can balance nutrient demand and availability by regulating uptake, accumulation and exudation. To obtain insight into these processes under nitrogen (N) and phosphorus (P) limitation, we reanalyze published data from continuous cultures of the chlorophyte Selenastrum minutum . Based on mass budgets, we argue that much of the non-limiting N and P had passed through the organisms and was present as dissolved organic phosphorus or nitrogen (DOP or DON). We construct a model that describes the production of biomass and dissolved organic matter (DOM) as a function of the growth rate. A fit of this model …

Hydrolysis Of Palm Oil Mill Effluent Using Enzymes From Spent Mushroom Substrate Of Pleurotus Pulmonarius (Fr.) Quel, Mat Yunan Nurul Anisa

Student Works (2020-2029)

Mushroom cultivation and palm oil industry in Malaysia have contributed to the large volumes of lignocellulosic residues. Lignocellulolytic enzymes profiles (lignin peroxidase, laccase, xylanase, endoglucanase, and β-glucosidase) of Pleurotus pulmonarius (parents strains UMP001 and UMP 002, and the hybrid UMH004) during growth in sawdust substrate bags were investigated. The enzymes extracted from the spent mushroom substrate (SMS) of the strain with the highest enzymes productivity was used to hydrolyse palm oil mill effluent (POME). Optimization of parameters for POME hydrolysis to release reducing sugar was conducted using central composite design (CCD) of response surface methodology (RSM). The potential of hydrolysed …

Abundance And Distribution Of Microplastics And Persistent Organic Pollutants In Selected Rivers Of Peninsular Malaysia, Anuar Norkhairiyah

Student Works (2020-2029)

Nearly 70 to 80 percent of microplastics are believed to be transported to the sea through rivers. Yet, less attention has been given to the accumulation of microplastics in the freshwater environment. They are emerging anthropogenic contaminants on account of their potential to adsorb and/or release POPs from and/or to the surrounding environment, and become the vector transferring these pollutants from water to the food web. This study is aimed to explore the abundance and distribution of microplastics and POPs in six rivers of Peninsular Malaysia, which comprised of three rivers from the West Coast (Sepetang River, Serkam River, and …