ABSTRACT
Microbial processing of coal and minerals has been suggested by several authors for many potentially economically favorable reasons. Because of the many advances in the field of biotechnology, these techniques are finding application in a number of novel areas. One of these "new" areas is that of coal bioprocessing. The major division in coal biotechnology is between the use of microorganisms for coal cleaning or coal beneficiation and their use in transforming coal into a liquid or gaseous product. A wide range of microorganisms is used, from simple autotrophic bacteria to the filamentous fungi. Coal cleaning relates directly to the early body of work on the role of bacteria in acid mine drainage, this area of microbial coal interaction has seen the most progress. Greater than 50 to 60% slurries are needed in order to improve the process economics of microbial desulfurization. Large cell concentrations are also needed at this high coal loading.
