To evaluate the microbial removal of organically bound sulphur from coal suitable micro-organisms, known to desulphurize model compounds such as dibenzothiophene, will be investigated concerning the determination of degradation mechanisms and the isolation and characterization of responsible enzymes. A test system will be developed to prove and determine the desulphurization of model compounds.
Asea Brown Boveri (ABB) will isolate microorganisms in screening experiments with aromatic sulphides and thiols as sulphur source. The subsequent characterization of the organisms, concerning the ability to attack the organic sulphur, will include the application of several other model compounds and special coal qualities. Pure cultures will be characterized morphologically and physiologically.
The investigation of the degradation mechanisms of organic sulphur compounds will provide useful indications on the type of microorganism suitable for the organic sulphur bio-removal process. The metabolic reaction steps will be investigated by isolation and identification of metabolites of the bio-desulphurization. To identify metabolites biological test procedures will be evaluated. Additionally the degradation mechanisms of several different strains should be characterized and compared with respect to an application. This aspect should lead to the identification of ways of enhancing organic sulphur bio-removal.
The isolation and characterization of desulphurizing enzymes will be carried out exemplarily with different organisms known to desulphurize model compounds and will comprise following investigations: (1) Mass cultivation and cell disintegration; (2) development of an assay system; (3) enzyme purification; (4) enzyme classification; (5) substrate specificity; (6) further characterization.
The results of enzyme characterization will be closely linked to the investigation of the degradation mechanisms of organic sulphur compounds with respect to bioassay development and evaluation.
This will contribute to evaluate enzymes of different biological origin for their ability to attack various sulphur bonding types. Thus it will be possible to assess the chance of developing a microbial/enzymatic process to remove organic sulphur from coal.
Funding SchemeCSC - Cost-sharing contracts