Metabolism of Alkanes and Degradation of Chlorinated Ethenes by the Bacterium Pseudomonas butanovora Kate Bateman Mentors: Dr. Daniel Arp David Doughty Department of Botany and Plant Pathology

BIOREMEDIATION: P. butanovora is capable of removing harmful chemicals (chlorinated ethenes) from the environment

Uses: Industrial cleaners and creation of plastics Extensive groundwater pollution Drinking water pollutants: Toxic to the liver, kidneys, and nervous system Linked to cancer and birth defects EPA goal for complete removal not yet reached Trichloroethylene (TCE) Plume

BMO enzyme: Butane monooxygenase -Oxidizes alkanes (ethane, propane, butane) -Cooxidizes variety of chlorinated ethenes

Example of a bioreactor Goal: Understand relationship between metabolism of their food source and cometabolism of toxic compound Pump organisms and their food (alkane) into the contaminated ground water

Objective: Determine the relative affinity of the BMO enzyme’s active site for a range of alkanes

Propane Butane

1 2 3 Nothing competes with propane Ethane competes with propane Butane competes with propane

 (Decreasing alkane concentration)  (Increasing affinity for BMO active site)

Goal: Examine relationship between metabolism of the alkane and cometabolism of the chlorinated ethene while the culture is growing

72% 87%

76% of TCE degraded 94% of TCE degraded

BMO’s active site has a higher affinity for butane than ethane Butane-grown cultures degrade more TCE and at a faster rate than ethane or propane-grown cultures

Howard Hughes Medical Institute Dr. Daniel Arp Dave Doughty