Bacterial oxidation, previously known as bacterial leaching or bio-leaching, has been applied at laboratory and pilot plant scale to many refractory ores and concentrates around the world. The most common bacterial culture used in this process has been Thiobacillus sp. This organism is limited in commercial application, especially in Australia for several reasons. The optimum operating temperature range for this culture is 30C to 40C and high levels of some metals such as arsenic, silver, and copper have toxic effects on the culture thus reducing its effectiveness._x000D_
The culture employed by BacTech (Australia) Pty lid is a moderately thermophilic culture which operates in a temperature range of 40C to 55C (which is more amenable to the Australian climate) and with higher resistance levels to metals often found to be toxic to Thiobacillus sp..