After 5 weeks of testing by progressively diluting the bacteria sample in SSM (Sulfur selective media) and CSM (Carbon Selective media) in both Methyl Parathion and Paraoxon condition it was determined what type organophosphatase activity is found in this bacteria sample after growth in a media rich dish. SSM consistently had more turbidity than the CSM (Carbon selective media) , but only the PX (paraoxon) samples ever had a breakdown to form the yellow color p-nitrophenol product in both, turbidity or no; MP, or Methyl Parathion media NEVER had yellow coloration. This trend stayed throughout, but eventually only the CSM had a yellow color in the 5th week trial with almost no turbidity in any sample. The final trial's SSM PX should still have had a yellow color, but it may have been due to a too great dilution of the soil bacteria by this point that it could not break down the Paraoxon, whereas the CSM-PX had just enough to break down the Paraoxon. However, my bacteria in particular grew best on an SSM based on turbidity consistently staying higher in the SSM tubes. This means that it is a bacteria that breaks down Paraoxon in order to obtain its sulfur or carbon products; the slightly higher level of turbidity in the SSM media throughout the 5 weeks may indicate the bacteria prefers sulfur for growth.
Date of Collection