User:Jonathan Cline/Notebook/Melaminometer/Brainstorming

Designing the plasmid

Which enzymes should we produce?

Per the second bullet point at User:Jonathan_Cline/Notebook/Melaminometer/Toxicology_Details, it sounds like melamine and cyanuric acid aren't that harmful in isolation, but when combined they produce renal toxicity by forming the melamine cyanurate salt. Should we think about developing multiple strains of test bacteria, one which reports the presence of melamine and one which reports the presence of cyanuric acid? Or should we develop a plasmid which carries reporters for both melamine and cyanuric acid (with different colours, e.g. yellow and blue?)

Pros:

• More realistic determination of risk
• Single strain has a simple detection protocol -- if the sample turns yellow there's melamine, if it turns blue there's cyanuric acid, if it turns green, there's both!

Cons:

• Two strains of bacteria = more complicated process
• Cyanuric acid is a product of melamine degradation, so if the test organism contains the full melamine degradation pathway, the whole sample will start out yellow, shift to green, and finally turn blue as melamine is deaminated into cyanuric acid.
  • Could solve this problem by only including melamine deaminase and cyanurate amidohydrolase, i.e., the first step of each pathway. Melamine deaminase will deaminate the melamine twice, but the third deamination never takes place if there's no ammelide aminohydrolase. Thus, the sample will only turn green if both melamine and cyanuric acid are present.