ABSTRACT
Since the energy crisis in the 1970s, interest in coal as an energy source for production of electric power has increased. However, the feasibility of coal use for electric energy purposes has decreased because of recent stringent environmental regulations. The microorganisms involved in sulfur removal from coal are generally characterized by their unique capability to obtain metabolic energy from reactions involving sulfur. Bacteria such as Thiobacilli, Beggiatoa, and Sulfolobus are sulfur-oxidizing organisms that use aerobic-respiratory oxidation of sulfur and sulfide to sulfate as a source of energy. Sulfur-oxidizing bacteria were inoculated to flasks containing their respective mineral media containing 10% coal pulp density. For the inoculation with B. alba, the culture medium was centrifuged and 1.5 g wet weight of cells was used for 300 mL of medium. Control flasks were used to determine nonbiological sulfur removal from lignite.
