ABSTRACT
Coal is a major energy source, surpassed only by crude oil. Nevertheless, the use of coal is a real and potential threat to the environment since undesirable by-products generated by combustion are likely to be released into the atmosphere, water, and soil. Microbial oxidation of coal has been strongly supported by early laboratory works in which biodegradation of coal was performed. Despite early and recent efforts, bioliquefaction of coal is still incipient. In most environments and processing conditions, resistence of coal to biodegradation can be attributed to its stable molecular structure. Taking into account the points raised here; the present research consists of three parts that were executed as a preliminary effort designed to optimize of the biodegradation of lignite. Biodegradation of low-rank coal such as lignite is not easy. Nevertheless, based on evidence obtained from chemical degradation of lignites and proposed features for its structure, it is speculated that biodegradation of lignite is feasible.
