Engineering a celG Mutation in Vibrio fischeri Bacteria and its Effects on Cellobiose Metabolism and Cellobiose-Induced Gene Expression
Advisor(s)
Dr. Karen Visick, Loyola University Medical Center
Location
Room B115
Start Date
26-4-2019 10:45 AM
End Date
26-4-2019 11:00 AM
Abstract
Vibrio fischeri bacteria colonize the Euprymna scolopes bobtail squid, and are most commonly known for their unique ability to provide bioluminescence to the squid. However, motility and biofilm formation are two other traits known to be important for squid colonization. To conduct research on this type of bacterial behavior, it is useful to develop strains in which the natural regulatory control is replaced with an inducible system, such that biofilms or motility can be switched on or off with an inducer. One such inducible system uses the cellobiose-inducible promoter Pcel. Through this promoter, we can use flrA and fliQ to induce motility, and sypA to induce biofilms. Inducibility is lost, however, when the CelG protein is able to degrade cellobiose. Using PCR splicing with antibiotic-resistance cassettes, we generated an ES114 Vibrio fischeri mutant lacking celG, thus lacking the ability to degrade cellobiose. We then tested growth of Vibrio fischeri under various conditions: different nutrients, temperatures, gene deletions, and trimethoprim-resistant cassette insertion for complementation of a gene, using both biofilm and motility assays. Results can show how mutations and nutrient conditions affect Vibrio fischeri, which serves as a model for other symbiotic systems.
Engineering a celG Mutation in Vibrio fischeri Bacteria and its Effects on Cellobiose Metabolism and Cellobiose-Induced Gene Expression
Room B115
Vibrio fischeri bacteria colonize the Euprymna scolopes bobtail squid, and are most commonly known for their unique ability to provide bioluminescence to the squid. However, motility and biofilm formation are two other traits known to be important for squid colonization. To conduct research on this type of bacterial behavior, it is useful to develop strains in which the natural regulatory control is replaced with an inducible system, such that biofilms or motility can be switched on or off with an inducer. One such inducible system uses the cellobiose-inducible promoter Pcel. Through this promoter, we can use flrA and fliQ to induce motility, and sypA to induce biofilms. Inducibility is lost, however, when the CelG protein is able to degrade cellobiose. Using PCR splicing with antibiotic-resistance cassettes, we generated an ES114 Vibrio fischeri mutant lacking celG, thus lacking the ability to degrade cellobiose. We then tested growth of Vibrio fischeri under various conditions: different nutrients, temperatures, gene deletions, and trimethoprim-resistant cassette insertion for complementation of a gene, using both biofilm and motility assays. Results can show how mutations and nutrient conditions affect Vibrio fischeri, which serves as a model for other symbiotic systems.