What’s next:

• Other possible driving forces for DNA translocation into a cell and other mechanisms by which transformation may occur in E. coli must be explored.
• The reason why transformation is more frequent at the optimal pH must be determined.
• Proteins spanning the membrane that are required for DNA translocation function best when entirely immersed entirely in their ideal pH. This ideal pH is likely the intracellular pH of about 7.5. An extracellular pH of just over 7.4 (which was found to be optimum for transformation) would thus allow the proteins to function best.
• This hypothesis could be tested by tracing radioactively marked DNA to membrane proteins as cells are transformed. These proteins could possibly be isolated and tested at different pH levels.
• Testing smaller pH increments around optimum pH levels could better define optimal pH and suggest other mechanisms of transformation.
• This experiment should be repeated with more trials in the acidic range, to determine if the observed transformation increase from pH 7.31 to pH 5.95, in the third experiment, is a result of error.
• The extracellular pH at various stages of competence development and transformation should be altered to determine in which way and to what extent extracellular pH influences each stage.
• For natural transformation, competency only increases with an increase in PMF in the later stages of competence development. Furthermore, naturally competent bacteria can retain competence at a lower pH than DNA can be acquired at.
• Further testing should be done on the correlation between population density and transformation frequency in E. coli, to determine if population density has an impact on transformation frequency before plating.
• This experiment should be repeated using naturally transformable bacteria and chromosomal DNA in soil microcosms, to determine at what soil pH the risk of natural transformation from transgenes is greatest. pH levels particularly around pH 7.4 should be investigated.