The present paper studies anaerobic bio-leaching of manganese nodules by Thiobacillus ferrooxidans separated from mining water. With the addition of suitable nutrient and reductant, the metals existing in the nodules, such as Cu, Co, Ni and Mn can be leached effectively in an acidic and anaerobic system under ambient temperature in 3 days. Manganese oxide, and nickel sulfide participate in the respiration of the microbe as electron acceptor and donor respectively. Meanwhile, the ferric/ferro ions act as electron shuttles to accelerate the process. (c) 2005 Elsevier Ltd. All rights reserved.