|
KMID : 0545119940040030204
|
|
Journal of Microbiology and Biotechnology
1994 Volume.4 No. 3 p.204 ~ p.209
|
|
|
Syntheis of an Aspartame Precursor Using Immobilized Thermolysin in an Organic Solvent
|
|
Ahn, Kyung Seop
Lee, In Young/Kim, Ik Hwan/Park, Young Hoon/Lee, Sun Bok
|
|
|
Abstract
|
|
|
|
The synthesis of N-(benzyloxycarbonyl)-L-aspartyl-L-phenylalanine methylester (Z-APM), a precursor of aspartame, from N-(benzyloxycarbonyl)-L-aspartic acid (Z-Asp) and L-phenylalanine methylester hydrochloride(L-PM·HCl) was investigated in a saturated-ethylacetate single phase system using immobilized thermolysin. Among the various supports tested, glyceryl-CPG was found to be most efficient for retaining enzyme activity. The enzyme immobilized onto glyceryl-CPG also showed the highest activity for Z-APM synthesis in saturated ethyl acetate. Z-APM conversion yield in saturated ethylacetate was half of that obtained in an ethylacetatebuffer two-phase system under the same reaction conditions. However, as the mole ratio of L-PM·HCl to Z-Asp was increased to 4.0, the conversion yield reached 95 %. When continuous synthesis of Z-APM was carried out in a plug flow reactor (PFR) with 80mM of L-PM·HCl and 20mM of Z-Asp in saturated ethylacetate (pH 5.5), more than 95 % of Z-Asp was converted to Z-APM with a space velocity of 1.16 hr^-1 at 40℃. Although the operational stability in PFR was reduced rapidly, more than 80% of initial activity was maintained in CSTR even after a week of operation.
|
|
|
KEYWORD
|
|
|
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
  
|
|