The Institute of Enzyme and Metabolism Engineering (IEME) :



The Institute of Enzyme and Metabolism Engineering (IEME) was established in 2007 to study the new methods of using enzymes in nonconventional media for developing completely new processes. Now, it is focused on a national project with the subject of
Achieve the technical science and method of 'Enzymatic Gas Phase Reactions' to produce high added-value and fine chemicals

An overlook to the project:
'Enzymatic gas-phase reaction' involves conversion of gaseous substrate to gaseous product using dry enzyme as catalyst. By this technology, enzyme is more stable than other conventional aqueous or organic media and there are no solvent interaction problems. Volatile organic compounds (VOC) are the best substrates both for producing petrochemicals and fine products such as flavors. Esterification reactions and producing many kinds of esters (such as ethyl acetate) without severe operating condition (reactive distillation and ...), alcohol and pharmaceutical fine products (penicillin, etc) are other achievable reactions. This method offers many advantages compared to conventional biocatalysis, which includes;
1.Substrate and product are in the gaseous phase and the biocatalyst is in the dry state; therefore the immobilization of the enzyme and its cofactor is much simplified. Recovery and recycling of the immobilized enzyme preparation is possible.

2.The enzyme and its cofactor in a dry state with controlled water content are more resistant to thermo-inactivation; therefore reactions can be performed at elevated temperature. In addition, the reaction can be performed for longer duration.

3.The substrates employed are pure and the addition of solvent can be avoided. Hence, the toxicity of solvent towards the catalyst or the final consumer of the product can be avoided. The amount of by-product is limited.

4.Downstream processing is simplified due to the absence of solvent. The gas-phase products and unreacted substrate can be separated and recovered with high purity by fractional condensation.

5.Diffusion coefficients of the substrate and the product in the gas-phase are more than 103 times higher than in the liquid-phase.

6.Volatile, toxic or inhibitory substances can be continuously removed.

7.Independent variation of thermodynamic activities of the different reaction species is possible. Therefore, the effect of each compound on the activity and the thermo-stability of the catalyst can be evaluated.

8.Since the bioreactors are operated at high temperatures, there is no danger of microbial contamination.