Enzymes and bacterial metabolites directly or indirectly are pathogenesis mediators. In many pathosystems, these mediators are identified and well characterized. Still, many of them remain to be discovered, representing a serious challenge to science. This problem is particularly difficult when the pathogens cannot be cultured in a laboratory setting. In those cases, the scientific approach should integrate a battery of scientific disciplines where genomics, proteomics, and bioinformatic predictions are central in pinpointing potential mechanisms to be studied. Our lab accepted this contest designing a set of strategies to work in this complex framework. Thus, we devote part of our research effort to identifying and blocking pathogenicity determinants of Ca. Liberibacter asiaticus, the causing agent of citrus greening disease. This unculturable bacteria is decimating citrus cultivars worldwide; the Florida citrus industry has already suffered consequences. Our laboratory contributed to the isolation and characterization of: 1) key transcription factors regulating the gene expression of this pathogen (Pagliei et al., 2014; Pan el at., 2021). 2) novel regulatory proteins controlling proteolytic activity at the posttranscriptional level (Loto el at., 2017; Merli et al., 2021), 3) small molecules affecting the biological activity of central pathways affecting Ca. L. asiaticus viability (Garner et al., 2016; Zuo et al., 2019; Coyle et al., 2018).

We have described a biological system by which a commensal bacterium, inhabitant of the gastrointestinal tract (GI), could change the fate of the GI tryptophan ingested. (Valladares et al; 2010). As a result, these commensals are linked to serotonergic neurostimulation diminishing GI inflammation. To us, this opens an important window of research directing our efforts to study the mechanisms of tolerogenesis. Our comprehensive approach involves research from both sides of the problem to understand the physiology of the bacteria (Valladares et al., 2015) and the physiological responses observed in the host (Kling et al., 2018; Teixeira et al., 2021).

Our next step is to identify the immunoreactive components of this strain to connect the events taking place in the GI organs with more systemic effects. The group of bioactive components to which we are directing our attention are the bacteria-biosynthesized lipids. Gut microbial-derived lipids are structurally unique and can modulate the host’s immunity. We recently reported that bacterial-purified lipids induce important transcriptional shifts in dendritic cells. We will use this fundamental knowledge to design future lipid-based therapeutics (Cuaycal et al., 2023).

Admissions and Application Information

The University of Florida Graduate School requires an undergraduate grade point average (GPA) of 3.0 to be eligible for admission. Fulfillment of the minimum requirement does not guarantee an applicant’s acceptance into the program. In evaluating each applicant, the department’s Graduate Committee members include in their consideration a thorough review of the transcript, letters of recommendation, statement of purpose, area of research interest, etc. Students are encouraged to complete undergraduate coursework in biochemistry and microbiology before they apply.

How to Apply

Admission into the UF Microbiology and Cell Science graduate program requires that an applicant be accepted both by the UF Graduate School and by the Microbiology and Cell Science Department. To complete the application process, apply online via the Graduate School admissions web site and select the “Graduate” option to create an account and begin your application. Visit the UF Graduate School web page for step-by-step instructions on how to apply. Select the “Apply Now” icon below to go directly to the Ph.D. Application.

Students are admitted to the PhD program each fall semester. Applications must be completed by December 15th to be considered for admission the following fall semester.

We are not currently accepting applications for the thesis master’s degree program.

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Required Application Materials

• Application fee of $30.
• Official Transcripts.
• CV or resume.
• Three letters of recommendation (LOR). We suggest that candidates request LOR from professional/academic mentors or colleagues that can comment on their academic/research experiences.
• Personal statement. The personal statement should consist of a brief essay describing your research experience, career goals, and area of research interest (limit 500 words)
• Supplemental information. Use this form to provide additional information that will be reviewed by the admissions committee
• International Applicants must also submit TOEFL scores (a score of 23 or higher on the speaking section is required to be considered for admission).
  • TOEFL Score Codes for UF: Institution Code is 5812, Department Code is 07
  • We do not accept the IELTS

Please contact Jacqueline Lee at jlee9@ufl.edu if you have any questions regarding the application process or deadline.