Preparation of L-aspartic acid by means of immobilized Alcaligenes metalcaligenes cells

Biotechnology and Bioengineering
V VojtsekJ Netnral

Abstract

Two types of biocatalysts based on immobilized cells of Alcaligenes metalcaligenes exhibiting aspartate ammonia-lyase activity (EC 4.3.1.1) were developed for the enzymic preparation of L-aspartic acid from ammonium fumarate. The first type of the biocatalyst consists in individual covalently crosslinked and permeabilized cells(I), while the second type is represented by cell aggregates (II). For the above preparation, biocatalyst I can be used only discontinuously in a mixed reactor. After termination of the reaction between individual cycles of its use, the biocatalyst is returned to the reactor in the form of a highly concentrated cell suspension or paste. Biocatalyst II can be used discontinuously or continuously in a fixed-bed column of the catalyst. The effects of pH, substrate concentration and temperature on the reaction velocity and effectivity of enzymic conversion was investigated. Optimal parameters of the reaction are as follows: pH 8.5, initial substrate concentration, 1.35 mol/L, temperature for discontinuous process, 37 degrees C, and temperature for continuous process, 25 degrees C. Under these conditions the enzymic conversion of substrate to product is quantitative. Under optimal toring conditions, the specif...Continue Reading

References

Jul 8, 1977·Biochimica Et Biophysica Acta·T TosaI Chibata
Jan 1, 1983·Folia Microbiologica·V Vojtísek, V Jirků
Jan 1, 1981·Annual Review of Biophysics and Bioengineering·I Chibata, T Tosa

Related Concepts

Acids
Aspartate Ammonia-Lyase
Aspartic Acid
Suspensions
Ammonium fumarate
Cells, Immobilized
Discontinuation (Procedure)
Type 1 Vestibular Sensory Cell

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