Sunday, March 21, 2010
Writing at FireDogLake, Jim White discusses the role of silicon in the anthrax spores. Apparently, the mechanism for 2 liter cultures of anthrax available to Bruce Ivins did not require an antifoaming agent, and he did not use one. OTOH, large volume fermenters with compressed air (or a gaseous mixture) pumped into the culture medium do need the addition of an antifoaming agent. Silicon-containing agents are popular, although agents are available without silicon. Simethicone (a possibly effective medicinal treatment for "gas" pains that acts by reducing surface tension on gas bubbles) is one such agent. Its inclusion in a fermentation might have led to a concentration of silicon compounds similar to what was found in the anthrax letters. Much good technical information here.
Posted by Meryl Nass, M.D. at 12:25 AM