{"629645":{"#nid":"629645","#data":{"type":"event","title":"Phd Defense by   Luz Karime Medina Cordoba","body":[{"value":"\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EIn partial fulfillment of the requirements for the degree of\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EDoctor of Philosophy in Biology\u003C\/p\u003E\r\n\r\n\u003Cp\u003Ein the\u0026nbsp;\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\u003ELuz Karime Medina Cordoba\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003Ewill defend her dissertation\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EBiofertilizers for Sustainable Agriculture: Isolation and Genomic Characterization of Nitrogen-Fixing Bacteria from Sugarcane\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003ETuesday, December 10, 2019\u003C\/p\u003E\r\n\r\n\u003Cp\u003E1:00 PM\u003C\/p\u003E\r\n\r\n\u003Cp\u003EKlaus\u0026nbsp;Advanced Computing Building\u003C\/p\u003E\r\n\r\n\u003Cp\u003EConference Room\u0026nbsp;1116 East\u0026nbsp;\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\u003EDr. Joel E. Kostka\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\u003ECo-Advisor:\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003EDr. I. King Jordan\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\u003EDr. Frank Stewart\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\u003EDr. Jung H. Choi\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\u003EDr. Leonard W. Mayer\u003C\/p\u003E\r\n\r\n\u003Cp\u003ESchool of Medicine\u003C\/p\u003E\r\n\r\n\u003Cp\u003EEmory University\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EAbstract\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003EThe goal of my thesis research was to explore the use of bacterial biofertilizers, as an alternative or complementary approach to chemical fertilizers, in support of more sustainable agricultural practices.\u0026nbsp; To this end, I worked to discover and characterize native nitrogen-fixing bacteria that are associated with sugarcane crops cultivated in the Cauca Valley of Colombia.\u0026nbsp; I hypothesized that native nitrogen-fixing bacteria, found in association with local sugarcane crops could serve as potent biofertilizers with the potential to simultaneously increase crop yield while reducing the reliance on chemical fertilizers.\u0026nbsp; I evaluated this hypothesis by isolating nitrogen-fixing bacteria isolated from Colombian sugarcane fields and characterizing their plant growth-promoting (PGP) potential using an integrated computational genomics and experimental approach.\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EA high-throughput cultivation approach was developed and applied for the enrichment and isolation of nitrogen-fixing bacteria from environmental samples.\u0026nbsp; Pure cultures of nitrogen-fixing bacteria were isolated and tested for diazotrophic potential by PCR amplification of \u003Cem\u003EnifH\u003C\/em\u003E genes, a common molecular marker for nitrogen-fixing capacity, and twenty-two distinct \u003Cem\u003EnifH\u003C\/em\u003E positive isolates were selected for genome sequencing and analysis.\u0026nbsp; Genome sequence analysis confirmed the presence of intact \u003Cem\u003EnifH\u0026nbsp;\u003C\/em\u003Egenes and operons in the genomes of 18 of the isolates, and isolate genomes were found to encode operons for phosphate solubilization, siderophore production, and other PGP phenotypes.\u0026nbsp; I characterized 14 of the 22 nitrogen-fixing isolates as distinct strains of \u003Cem\u003EKlebsiella pneumoniae\u003C\/em\u003E, and four others were members of genera that are closely related to \u003Cem\u003EKlebsiella\u003C\/em\u003E.\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EComputational phenotype predictions for PGP traits were validated with a series of experimental laboratory assays for nitrogen fixation and phosphate solubilization as well as the production of siderophores, gibberellic acid, and indole acetic acid.\u0026nbsp; Results from the biochemical assays were consistent with the bioinformatic predictions for these isolates, in support of their PGP potential.\u0026nbsp; The quantitative approach to computational phenotyping that I developed and applied to sugarcane bacterial isolates facilitates the screening for strains that have a high potential for nitrogen fixation and other PGP phenotypes while showing minimal risk for virulence and antibiotic resistance.\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EFinally, I developed and validated an automated method to curate and continuously update a \u003Cem\u003EnifH \u003C\/em\u003Ereference sequence database, which can be used to support the characterization of metagenomic or environmental amplicon sequences.\u0026nbsp; This process yields a far smaller, but much more reliable, set of \u0026lsquo;gold-standard\u0026rsquo; \u003Cem\u003EnifH\u003C\/em\u003E sequences, against which users can compare their metagenomic or amplicon sequence data for accurate functional prediction and taxonomic characterization of environmental samples.\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":"","field_summary_sentence":[{"value":"Biofertilizers for Sustainable Agriculture: Isolation and Genomic Characterization of Nitrogen-Fixing Bacteria from Sugarcane"}],"uid":"27707","created_gmt":"2019-12-03 18:22:28","changed_gmt":"2019-12-03 18:22:28","author":"Tatianna Richardson","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2019-12-10T13:00:00-05:00","event_time_end":"2019-12-10T15:00:00-05:00","event_time_end_last":"2019-12-10T15:00:00-05:00","gmt_time_start":"2019-12-10 18:00:00","gmt_time_end":"2019-12-10 20:00:00","gmt_time_end_last":"2019-12-10 20:00:00","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":""}}}