{"648822":{"#nid":"648822","#data":{"type":"event","title":"PhD Defense by Hannah Lachmayr","body":[{"value":"\u003Cp\u003EIn partial fulfillment of the requirements for the degree of\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EMaster of Science in Biology\u003C\/p\u003E\r\n\r\n\u003Cp\u003Ein the\u003C\/p\u003E\r\n\r\n\u003Cp\u003ESchool of Biological Sciences\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EHannah Lachmayr\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EWill defend her thesis\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EAssay Development for and Evaluation of Sphingolipid Hydrolysis Activity in Isolated Soil Bacteria and Venoms from \u003Cem\u003ELoxosceles reclusa\u003C\/em\u003E and \u003Cem\u003EKukulcania hibernalis\u003C\/em\u003E\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EJuly 22\u003Csup\u003End\u003C\/sup\u003E, 2021\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003EAt 3:00 pm\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Ca href=\u0022https:\/\/bluejeans.com\/293947171\/9175\u0022\u003Ehttps:\/\/bluejeans.com\/293947171\/9175\u003C\/a\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EThesis Advisor:\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003EAlfred H. Merrill, Ph.D.\u003C\/p\u003E\r\n\r\n\u003Cp\u003ESchool of Biological Sciences\u003C\/p\u003E\r\n\r\n\u003Cp\u003EGeorgia Institute of Technology\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003ECommittee Members:\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003EKostas Konstantinidis, Ph.D.\u003C\/p\u003E\r\n\r\n\u003Cp\u003ESchool of Civil \u0026amp; Environmental Engineering\u003C\/p\u003E\r\n\r\n\u003Cp\u003ESchool of Biological Sciences\u003C\/p\u003E\r\n\r\n\u003Cp\u003EGeorgia Institute of Technology\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EThomas DiChristina, Ph.D.\u003C\/p\u003E\r\n\r\n\u003Cp\u003ESchool of Biological Sciences\u003C\/p\u003E\r\n\r\n\u003Cp\u003EGeorgia Institute of Technology\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EJanet Hatt, Ph.D.\u003C\/p\u003E\r\n\r\n\u003Cp\u003ESchool of Civil \u0026amp; Environmental Engineering\u003C\/p\u003E\r\n\r\n\u003Cp\u003EGeorgia Institute of Technology\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EAbstract: \u003C\/strong\u003ESeveral \u003Cem\u003ESicariidae\u003C\/em\u003E spiders, such as the brown recluse spider \u003Cem\u003ELoxosceles reclusa\u003C\/em\u003E, and some pathogenic bacteria contain phospholipase D (PLase D) enzymes that act on phospholipid substrates. PLases D that cleave sphingomyelin (SM) to release the headgroup choline are also called sphingomyelinases D (SMases D). Although the lipid product of the \u003Cem\u003EL. reclusa\u003C\/em\u003E SMase D was initially thought to be ceramide 1-phosphate (Cer1P), a transphosphatidylation mechanism has been shown to produce ceramide 1,3-cyclic phosphate (Cer(1,3)P). Since SMase D is presumably the major agent in the necrosis and toxicity of the brown recluse spider venom, a rigorous but simple assay would aid in detecting the presence of activities that convert SM to Cer(1,3)P. After synthesizing fluorescent products that are known to be made by various types of SMases (i.e., NBD-ceramide, -Cer1P and -Cer(1,3)P), a solvent was identified that fully resolves these compounds as well as the substrate NBD-SM using silica gel plates. When the assay was applied to venom from \u003Cem\u003EL. reclusa,\u003C\/em\u003E the product was the expected NBD-Cer(1,3)P. The assay was applied to venom from \u003Cem\u003EKukulcania hibernalis\u003C\/em\u003E, a spider that has been suggested to have SMase D but whose products have not yet been determined. NBD-Cer(1,3)P was found to be produced by \u003Cem\u003EK. hibernalis\u003C\/em\u003E venom. Since at least the venoms of \u003Cem\u003EL. reclusa\u003C\/em\u003E and \u003Cem\u003EK. hibernalis\u003C\/em\u003E hydrolyze SM to Cer(1,3)P, which is toxic to humans, we isolated bacteria from the soil with enzymatic activity to degrade this cyclic Cer(1,3)P product. Single isolates of soil microorganisms were selected based on their ability to grow on the restrictive carbon source SM or Cer(1,3)P and then examined for their cleavage of NBD-SM and\/or NBD-Cer(1,3)P. Genome sequencing of two isolates taxonomically matched to \u003Cem\u003EKlebsiella variicola\u003C\/em\u003E, a category of gram-negative bacterium that can be a human pathogen. Therefore, this work has resulted in a new methodology for analysis of the PLase D\/SMase D activities that produce Cer(1,3)P. The assay\u0026rsquo;s application has confirmed the nature of the SMase D in \u003Cem\u003EL. reclusa\u003C\/em\u003E venom and established that SMase D activity is also present in the venom of \u003Cem\u003EK. hibernalis\u003C\/em\u003E. Our findings have opened new lines of investigation into microorganisms that can metabolize sphingolipids and that could have potential clinical utility through cleaving Cer(1,3)P produced by necrotizing SMases D.\u003C\/p\u003E\r\n","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":"","field_summary_sentence":[{"value":"Assay Development for and Evaluation of Sphingolipid Hydrolysis Activity in Isolated Soil Bacteria and Venoms from Loxosceles reclusa and Kukulcania hibernalis"}],"uid":"27707","created_gmt":"2021-07-15 21:22:58","changed_gmt":"2021-07-15 21:22:58","author":"Tatianna Richardson","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2021-07-22T16:00:00-04:00","event_time_end":"2021-07-22T18:00:00-04:00","event_time_end_last":"2021-07-22T18:00:00-04:00","gmt_time_start":"2021-07-22 20:00:00","gmt_time_end":"2021-07-22 22:00:00","gmt_time_end_last":"2021-07-22 22:00:00","rrule":null,"timezone":"America\/New_York"},"extras":[],"groups":[{"id":"221981","name":"Graduate Studies"}],"categories":[],"keywords":[{"id":"100811","name":"Phd Defense"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[{"id":"1788","name":"Other\/Miscellaneous"}],"invited_audience":[{"id":"78761","name":"Faculty\/Staff"},{"id":"78771","name":"Public"},{"id":"174045","name":"Graduate students"},{"id":"78751","name":"Undergraduate students"}],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[],"email":[],"slides":[],"orientation":[],"userdata":""}}}