, Volume 5, Issue 1, pp 55–62 | Cite as

Comparison of coal solubilization by bacteria and fungi

  • Albert P. Torzilli
  • Jenefir D. Isbister


Coal-solubilizing agents produced byTrametes versicolor, Phanerochaete chrysosporium, Aspergillus sp., a bacterial consortium, and a bacterial isolate,Arthrobacter sp., from that consortium were compared in terms of pH dependence, thermostability, molecular mass, mechanism of action, and product diversity. The thermostability and low molecular weights exhibited by the coal-solubilizing agents indicated a non-enzymatic mechanism of action. Competition studies using cupric copper indicated that coal solubilization by these agents involved metal chelation. Results demonstrated that oxalate could account for some but not all of the coal solubilization observed forT.versicolor andP.chrysosporium. The very low levels of oxalate detected inAspergillus sp. and the bacterial cultures indicated that oxalate is not an important factor in coal solubilization by these microbes. When subjected to gel permeation chromatography, the soluble coal products generated by each microbial coal-solubilizing agent yielded unique molecular mass profiles suggesting substantial product diversity. Such diversity increases the possibility of identifying potentially valuable compounds and extending the commercial utilization of coal.

Key words

ammonia bacteria chelation coal solubilization fungi oxalate 


A450, A260

absorbances respectively at 450 nm and 260 nm


coal-solubilizing agent


coal-solubilizing unit


gel permeation chromatography


malt extract agar


potato dextrose agar


Sabouraud dextrose agar


Sabouraud dextrose broth


standard error of the mean




trypticase soy agar


trypticase soy broth


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Copyright information

© Kluwer Academic Publishers 1994

Authors and Affiliations

  • Albert P. Torzilli
    • 1
  • Jenefir D. Isbister
    • 1
  1. 1.Biology DepartmentGeorge Mason UniversityFairfaxUSA

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