Effect of Nutrient Availability on Natural Competence in Variovorax paradoxus MF295
Poster Number
35
Faculty Mentor Name
Paul Orwin
Research or Creativity Area
Natural Sciences
Abstract
Natural transformation is the process of bacterial uptake of DNA from their environment. This process is important in biofilm formation, bacterial nutrition, DNA repair, and horizontal gene transfer. The ability to take up environmental DNA is called competence, and can be influenced by environmental conditions such as nutrient availability. We investigated how nutrient limitation affects transformation competence in the bacterial strain Variovorax paradoxus strain. MF295. A bacterial culture was grown to log phase (OD ~0.3) in 0.5 g/L yeast extract (YE), then pelleted and resuspended in the same medium, 10 and 100 fold dilutions, or PBS to impose nutrient limitation prior to plasmid exposure. The bacteria were incubated with plasmid DNA for approximately 3 hours at 30°C to allow uptake, while no-DNA controls received water. Cultures were plated on selective (YE + kanamycin) and non-selective (YE agar) media to quantify transformants (T) and to detect spontaneously resistant mutants. Transformation frequency was then calculated as transformants per microgram of DNA. Our goal is to understand how changes in nutrient availability influence DNA uptake. We hypothesize that moderate nutrient limitation will increase transformation competence due to stress-induced DNA uptake, while extreme limitation (such as PBS) may reduce transformation because cells become too stressed to survive. Based on this, we predict the highest transformation frequency at 1/100 YE, with a possible decrease under PBS conditions. Overall, this study helps us better understand how environmental stress, such as nutrient availability, influences gene transfer and microbial adaptation.
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 Nutrient Availability on Natural Competence in Variovorax paradoxus MF295
University of the Pacific, DeRosa University Center
Natural transformation is the process of bacterial uptake of DNA from their environment. This process is important in biofilm formation, bacterial nutrition, DNA repair, and horizontal gene transfer. The ability to take up environmental DNA is called competence, and can be influenced by environmental conditions such as nutrient availability. We investigated how nutrient limitation affects transformation competence in the bacterial strain Variovorax paradoxus strain. MF295. A bacterial culture was grown to log phase (OD ~0.3) in 0.5 g/L yeast extract (YE), then pelleted and resuspended in the same medium, 10 and 100 fold dilutions, or PBS to impose nutrient limitation prior to plasmid exposure. The bacteria were incubated with plasmid DNA for approximately 3 hours at 30°C to allow uptake, while no-DNA controls received water. Cultures were plated on selective (YE + kanamycin) and non-selective (YE agar) media to quantify transformants (T) and to detect spontaneously resistant mutants. Transformation frequency was then calculated as transformants per microgram of DNA. Our goal is to understand how changes in nutrient availability influence DNA uptake. We hypothesize that moderate nutrient limitation will increase transformation competence due to stress-induced DNA uptake, while extreme limitation (such as PBS) may reduce transformation because cells become too stressed to survive. Based on this, we predict the highest transformation frequency at 1/100 YE, with a possible decrease under PBS conditions. Overall, this study helps us better understand how environmental stress, such as nutrient availability, influences gene transfer and microbial adaptation.
