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Full-Text Articles in Organismal Biological Physiology

Novel Microbial Guilds Implicated In N2o Reduction, Guang He Dec 2023

Novel Microbial Guilds Implicated In N2o Reduction, Guang He

Doctoral Dissertations

N2O is a long-recognized greenhouse gas (GHG) with potential in global warming and ozone depletion. Terrestrial ecosystems are a major source of N2O due to imbalanced N2O production and consumption. Soil pH is a chief modulating factor controlling net N2O emissions, and N2O consumption has been considered negligible under acidic conditions (pH <6). In this dissertation, we obtained solids-free cultures reducing N2O at pH 4.5. Furthermore, a co-culture (designated culture EV) comprising two interacting bacterial population was acquired via consecutive transfer in mineral salt medium. Integrated phenotypic, metagenomic and metabolomic analysis dictated that the Serratia population excreted certain …

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Discovering Novel Polyextremotolerant Fungi, And Determining Their Ecological Role Within The Biological Soil Crust Consortium, Erin Carr Jul 2022

Discovering Novel Polyextremotolerant Fungi, And Determining Their Ecological Role Within The Biological Soil Crust Consortium, Erin Carr

School of Biological Sciences: Dissertations, Theses, and Student Research

The ecological niche of polyextremotolerant fungi within oligotrophic ecosystems such as biological soil crusts has not yet been determined. These fungi persist in locations where nutrients are depleted while simultaneously surrounded by autotrophic microbes such as algae and cyanobacteria. Yet it has not been shown that they are engaging in any exchange of nutrients the way lichens do. However, there is seemingly no other way for these fungi to obtain vital nutrients, such as carbon or nitrogen, other than from these microbes. Here we have isolated polyextremotolerant fungi from cold desert biological soil crusts which are a microbial biofilm that …

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Screening The Cultivable Cave Microbial Mats For The Production Of Antimicrobial Compounds And Antibiotic Resistance, Jerneja Ambrožič Avguštin, Patricia Petrič, Lejla Pašić Dec 2019

Screening The Cultivable Cave Microbial Mats For The Production Of Antimicrobial Compounds And Antibiotic Resistance, Jerneja Ambrožič Avguštin, Patricia Petrič, Lejla Pašić

International Journal of Speleology

The current work extends the phenotypic characterization of a bacterial culture collection obtained from white, yellow, grey or pink microbial cave wall colonies that are common in the caves of Slovenian Karst. We have determined antibiotic resistance to 22 natural and synthetic antibiotics in 69 isolates from the microbial mats. Thirty-eight isolates (52%) were resistant to 1-5 antibiotics; another 27 isolates (37%) were resistant to 6-10 antibiotics; and 7 isolates (0.1%) were resistant to 11-17 antibiotics. We screened for production of antimicrobial compounds by growing cave isolates on five different media and overlaying individual cultures with ten Gram-positive and Gram …

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Drivers And Consequences Of Carbon Use Efficiency - And Its Measurement In Soil, Grace Pold Oct 2019

Drivers And Consequences Of Carbon Use Efficiency - And Its Measurement In Soil, Grace Pold

Doctoral Dissertations

Soils serve as massive carbon sinks, but their ability to continue this ecological service is contingent on how the resident soil microbial community will respond to the ongoing climate crisis. One key dimension of the microbial response to warming is its carbon use efficiency (CUE), or the fraction of carbon taken up by an organism which is allocated to growth rather than respiration. However, the scientific community is still in the early stages of understanding the drivers, consequences - and even accurate measurements of - CUE. In this dissertation, I first quantified the variability of CUE and its responsiveness to …

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Expansion Of And Reclassification Within The Family Lachnospiraceae, Kelly N. Haas Nov 2016

Expansion Of And Reclassification Within The Family Lachnospiraceae, Kelly N. Haas

Doctoral Dissertations

Many of the taxa in the family Lachnospiraceae are currently misclassified as Clostridium spp. Here attempt to rectify many of these issues, beginning with an in-depth genomic and physiologic analysis of Clostridium methoxybenzovorans, culminating in the assertion that is a heterotype of Clostridium indolis, followed by reclassification of the broader group in which this organism resides. We propose two novel genera, Lacriformis and Enterocloster, to reclassify this clade, this includes reclassification of Clostridium sphenoides, Clostridium indolis, Clostridium saccharolyticum, Clostridium celerecrescens, Clostridium xylanolyticum, Clostridium algidixylanolyticum, Clostridium aerotolerans, Clostridium amygdalinum, and …

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Isolation And Identification Of Bacterial Endosymbionts In The Brooding Brittle Star Amphipholis Squamata, Abbey Rose Tedford Jan 2016

Isolation And Identification Of Bacterial Endosymbionts In The Brooding Brittle Star Amphipholis Squamata, Abbey Rose Tedford

Honors Theses and Capstones

Symbiotic associations with subcuticular bacteria (SCB) have been identified and studied in numerous echinoderms, including the SCB of the brooding brittle star, Amphipholis squamata. These SCB, however, have not been studied using current next generation sequencing technologies. Previous studies on the SCB of A. squamata placed these bacteria in the genus Vibrio (γ-Proteobacteria), but subsequent studies suggested that the SCB are primarily composed of α-Proteobacteria. The present study examines the taxonomic composition of SCB associated with A. squamata from the Northwest Atlantic. DNA was extracted using a CTAB protocol and 16S rRNA sequences were amplified …

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Generation And Assessment Of Muscular Mutations In Caenorhabditis Elegans, Katie N. Reget May 2015

Generation And Assessment Of Muscular Mutations In Caenorhabditis Elegans, Katie N. Reget

DePaul Discoveries

A study of egg laying muscular mutations in C. elegans was conducted over a span of ten weeks. Parent (EGL-19) and wild type (N2) were exposed to mutagenesis and integration mutation techniques to generate genetic and physical different mutants. Overall, four genetic, physical and phenotypically unique worms were generated for the process of mutagenesis. The worms used in the process of integration were found to have shortened life spans, reduced size and decrease numbers of progeny.

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Karyotype Of Geomys Pinetis (Mammalia: Geomyidae), With A Discussion Of The Chromosomal Relationships Within The Genus, S. L. Williams, Hugh H. Genoways Jan 1975

Karyotype Of Geomys Pinetis (Mammalia: Geomyidae), With A Discussion Of The Chromosomal Relationships Within The Genus, S. L. Williams, Hugh H. Genoways

University of Nebraska State Museum: Mammalogy Papers

Summary. Four of the five subspecies of Geomys pinetis were karyotyped. All specimens examined had a diploid number of 42 and a fundamental number of 80. This karyotype was compared with the described karyotypes of other species of Geomys and was considered to be derived from an ancestoral form having a karyotype of about 70 acrocentric elements.

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