PhD Defense by Karen Moll
- Tuesday, April 20, 2021 from 11:00am to 12:00pm
Karen Moll, candidate in Microbiology & Immunology will present her dissertation defense “ALKALINE MICROALGAE FROM YELLOWSTONE NATIONAL PARK: PHYSIOLOGICAL AND GENOMIC CHARACTERIZATION” on Tuesday, April 20 at 11AM via Webex.
Meeting number: 1204200518 Meeting Password: WJd6MCraq64
Diatoms are known for atmospheric CO2 remediation and decreasing ocean acidification but they also have the potential for photosynthetic biodiesel production. With changes in global temperatures, it is important to characterize diatom genomes as they are integral to understanding global carbon fixation. Isolated from an alkaline stream (pH 9.3) in Yellowstone National Park (YNP), diatom strain RGd-1 has been shown in previous work to yield lipid concentrations up to 30-40% (w/w) triacylglycerol (TAG) and 70-80% (w/w) fatty acid methyl esters (FAMEs) that can be transesterified into biodiesel for biofuel applications. Here we report the 24 Mb draft genome for RGd-1, an extremophilic, freshwater, pennate diatom. RGd-1 was found to align best to the centric diatom, Thalassiosira pseudonana and Phaeodactylum tricornutum on a nucleotide and protein level, respectively. A de novo transcriptome assembly was used to annotate the RGd-1 genome assembly. RGd-1 was shown to have a nearly complete glyoxylate pathway that could be used as a carbon conservation strategy to accumulate high concentrations of neutral lipids. As part of the RGd-1 whole-genome sequencing project, we assembled an associated, novel 3.1 Mb Brevundimonas sp. genome. Nine major bacterial OTUs were found in the RGd-1 culture through 16S amplification and sequencing. Of those strains, seven may produce iron chelating siderophores, which could make iron biologically available to RGd-1 in an alkaline environment.
- Department of Microbiology & Immunology