Part:BBa_K4656013

pRha-mazE

Yogurt is one of the carriers of the engineered bacteria we have formulated as people generally prefer yogurt rather than capsules and yogurt itself has laxative properties. Although the product positioning is yet to be further confirmed due to policy constraints, we still designed a kill-switch circuit specialized for it. This part interplayed with part BBa_K4656010 to make up our yogurt-customized kill-switch circuit. During the transportation, consumption, and excretion of yogurt, we postulate the following three scenarios:

Scenario 1: the transportation scenario

The temperature is lower than 30 degrees, CI⁸⁵⁷ inhibits the promotor Pr, mazE is not expressed, while mazF is expressed. However, the yogurt with added rhamnose makes the engineered bacteria keep mazE expression at the same time, so the engineered bacteria can still survive.

Scenario 2: the in vivo scenario

The temperature is approximately 37 degrees, CI⁸⁵⁷ de-inhibits the promotor Pr, phif is expressed, and inhibits the promotor Pphif and downstream mazF expression, while mazE is expressed. The bacteria can survive regardless of whether there is sufficient concentration of rhamnose to induce mazE.

Scenario 3: the Ex vivo scenario

In the sewer system at temperatures below 30 degrees when engineered bacteria are excreted in feces, mazE is not expressed and mazF is expressed as mentioned before. At the same time, rhamnose is diluted and not enough to induce mazE， so the bacteria cannot survive anymore in the external environment.

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  COMPATIBLE WITH RFC[12]
• 21
  INCOMPATIBLE WITH RFC[21]

  Illegal BamHI site found at 196
  
• 23
  COMPATIBLE WITH RFC[23]
• 25
  COMPATIBLE WITH RFC[25]
• 1000
  COMPATIBLE WITH RFC[1000]