The Olympic Delivery Authority (ODA) says the bacteria, together with fungi and other microbes, will clean the soil as part of the green, high-tech clean up of the site.
The soil has suffered decades of contamination from petrol and diesel.
David Higgins, chief executive of the ODA, described the cleaning up of the Olympic Park as “incredibly challenging”.
“By utilising the latest technology we are transforming land contaminated by decades of industrial use and neglect into an area fit for world class sporting venues, a new urban park and the development of new communities,” he added.
Warm air, nutrients and water vapour is pumped through the soil in special bioremediation beds to increase the numbers of micro-organisms to speed up the process, which the ODA claims will make the soil clean and ready for reuse after a few weeks.
The site of the new Olympic Park used to employ 7,500 people in the manufacture of chemicals where there were few restrictions on the dumping of substances, according to indymedia.org.