Effect of Extended Incubation Time on Natural Competence in Variovorax paradoxus MF295
Poster Number
38
Faculty Mentor Name
Paul Orwin
Research or Creativity Area
Natural Sciences
Abstract
Natural competence is an important part of the process of generating genetic diversity in microbial populations. This process is defined as the uptake of naked DNA molecules from the environment. Many bacteria are capable of this type of uptake, based on genome content. Variovorax paradoxus MF295 is predicted to have natural competence activity based on the presence of specific DNA uptake genes. Bacterial transformation efficiency can be influenced by the amount of time cells are exposed to extracellular DNA. In this study we examined how incubation time with plasmid DNA affects transformation competence in Variovorax. Bacterial cells were exposed to a constant concentration and volume of plasmid DNA and incubated for different time intervals (30 minutes, 1 hour, 3 hours, 6 hours, and 24 hours) at 30°C. After each incubation period, the cells were collected, diluted, and plated on non-selective YE agar to determine total viable cell counts and on antibiotic-containing YE agar for transformants. Transformation efficiency is calculated as the number of transformants per microgram of added DNA. A negative control was included to ensure successful transformation and antibiotic selection, and to account for spontaneous resistance evolving. It is expected that transformation frequency will increase with longer incubation times due to increased time for DNA uptake, but will eventually reach a saturation point where additional incubation time produces little or no further increase. This experiment aims to determine the optimal incubation time for plasmid DNA uptake and better understand the time dependence of transformation in Variovorax
Location
University of the Pacific, DeRosa University Center
Start Date
24-4-2026 11:00 AM
End Date
24-4-2026 2:00 PM
Effect of Extended Incubation Time on Natural Competence in Variovorax paradoxus MF295
University of the Pacific, DeRosa University Center
Natural competence is an important part of the process of generating genetic diversity in microbial populations. This process is defined as the uptake of naked DNA molecules from the environment. Many bacteria are capable of this type of uptake, based on genome content. Variovorax paradoxus MF295 is predicted to have natural competence activity based on the presence of specific DNA uptake genes. Bacterial transformation efficiency can be influenced by the amount of time cells are exposed to extracellular DNA. In this study we examined how incubation time with plasmid DNA affects transformation competence in Variovorax. Bacterial cells were exposed to a constant concentration and volume of plasmid DNA and incubated for different time intervals (30 minutes, 1 hour, 3 hours, 6 hours, and 24 hours) at 30°C. After each incubation period, the cells were collected, diluted, and plated on non-selective YE agar to determine total viable cell counts and on antibiotic-containing YE agar for transformants. Transformation efficiency is calculated as the number of transformants per microgram of added DNA. A negative control was included to ensure successful transformation and antibiotic selection, and to account for spontaneous resistance evolving. It is expected that transformation frequency will increase with longer incubation times due to increased time for DNA uptake, but will eventually reach a saturation point where additional incubation time produces little or no further increase. This experiment aims to determine the optimal incubation time for plasmid DNA uptake and better understand the time dependence of transformation in Variovorax
