Team:Caltech/Biosafety

General Concerns

Subproject Concerns

Oxidative Burst

• Short Term: There are no safety concerns beyond that of typical E. coli lab strains. Considering that 260 mM H₂O₂ is applied directly to the skin to disinfect cuts and scrapes, the 800 uM H₂O₂ produced by the engineered strain should not be a health concern to anyone working in the lab.
• Long Term: Production of hydrogen peroxide is not a normal occurance in the large instestine, and its effects would need to be investigated before the engineered strain could be used to fight infection. Some concerns of hydrogen peroxide production in the intestine would be if:
  • it irritates the bowel¹.
  • it kills off significant amounts of the native gut flora.
  • it significantly damages gut epithelial cells.
  • the ability to produce peroxide can be transmitted to other gut flora.

Phage Pathogen Defense

Lactose Intolerance

Vitamin Production

Population Variation

• The current constructs consist of GFP behind promoters. GFP is not known to be hazardous. However, in the simple fimE constructs, when the promoter starts in the configuration pointing upstream, DNA upstream of the constructs may be transcribed by the cell.
• In the final design, the terminator that sits in the population variation generator may not be 100% efficient. Thus, the efficiency of the terminator should be tested before genes that are hazardous when co-expressed are placed into the system.

References

1. Ackermann M, Stecher B, Freed NE, Songhet P, Hardt WD, and Doebeli M. Self-destructive cooperation mediated by phenotypic noise. Nature 2008 Aug 21; 454(7207) 987-90.