The Effect of Incubation Time on Variovorax paradoxus MF295 Natural Competence
Poster Number
36
Faculty Mentor Name
Paul Orwin
Research or Creativity Area
Natural Sciences
Abstract
Variovorax paradoxus ability is a soil betaproteobacterium that plays key roles in plant growth promotion and biodegradation. Its ubiquity in nature has allowed it to gain importance in environmental microbiology, and its experimental tractability makes it appealing for studying these complex interactions. Natural competence is the capacity for bacteria to take up environmental DNA, and plays an important role in horizontal gene transfer in the environment. Our research on strain MF295 concerns the ability of Variovorax to uptake the pBBR8k-GFPuv plasmid, which carries a kanamycin resistance element. Our primary aim was to observe how time affects the ability of Variovorax to take up this plasmid from its environment. Initial experiments were also conducted to test Variovorax resistance to the antibiotic kanamycin at different concentrations. The plasmid was incubated with MF295 and was sampled at multiple time points after incubation. Cells were then plated onto media containing kanamycin to select for plasmid uptake. Our results showed that there was no positive correlation between incubation time and pBBR8k-GFPuv plasmid transformation. All plates showed negative microbial growth, indicating the bacteria were not transformed under all time conditions. Extended time in incubation did not improve nor inhibit transformation in Variovorax. Further experiments can be performed to determine if plasmid uptake occurs shortly after exposure to plasmid. Kanamycin resistant mutants appeared on select plates after plasmid exposure, but were tested using plasmid extraction and gel electrophoresis revealed that it could have been megaplasmid or chromosomal DNA. These findings suggest that other environmental or physiological factors, must be controlled in order to successfully induce natural competence in this organism.
Location
University of the Pacific, DeRosa University Center
Start Date
24-4-2026 11:00 AM
End Date
24-4-2026 2:00 PM
The Effect of Incubation Time on Variovorax paradoxus MF295 Natural Competence
University of the Pacific, DeRosa University Center
Variovorax paradoxus ability is a soil betaproteobacterium that plays key roles in plant growth promotion and biodegradation. Its ubiquity in nature has allowed it to gain importance in environmental microbiology, and its experimental tractability makes it appealing for studying these complex interactions. Natural competence is the capacity for bacteria to take up environmental DNA, and plays an important role in horizontal gene transfer in the environment. Our research on strain MF295 concerns the ability of Variovorax to uptake the pBBR8k-GFPuv plasmid, which carries a kanamycin resistance element. Our primary aim was to observe how time affects the ability of Variovorax to take up this plasmid from its environment. Initial experiments were also conducted to test Variovorax resistance to the antibiotic kanamycin at different concentrations. The plasmid was incubated with MF295 and was sampled at multiple time points after incubation. Cells were then plated onto media containing kanamycin to select for plasmid uptake. Our results showed that there was no positive correlation between incubation time and pBBR8k-GFPuv plasmid transformation. All plates showed negative microbial growth, indicating the bacteria were not transformed under all time conditions. Extended time in incubation did not improve nor inhibit transformation in Variovorax. Further experiments can be performed to determine if plasmid uptake occurs shortly after exposure to plasmid. Kanamycin resistant mutants appeared on select plates after plasmid exposure, but were tested using plasmid extraction and gel electrophoresis revealed that it could have been megaplasmid or chromosomal DNA. These findings suggest that other environmental or physiological factors, must be controlled in order to successfully induce natural competence in this organism.
