This paper concentrates on the application of a biohydrometallurgical method for processing deep-sea mineral resources. Bioleaching technologies developed for terrestrial sulfide minerals now can be applied for metal extraction from deep-sea hydrothermal sulfides. However, little attention has been given to the bioleaching of terrestrial oxide minerals. A potentially attractive bioleaching system using the Fe(III)-reducing bacterium has recently been proposed for manganese crusts and nodules. Experimental results obtained from these systems demonstrate that bioleaching is an economical and environmentally friendly processing avenue to recover valuable metals from deep-sea mineral resources.