Application of an immobilized Escherichia coli cell tube in analysis of L-threonine.

Abstract

Acetone-dried cells of Escherichia coli with an enhanced level of biodegradative L-threonine deaminase (EC 4.2.1.16) were easily and tightly immobilized to the inner surface of glass tubes by use of an emulsion-type of photo-crosslinkable resin prepolymer. A continuous flow system equipped with the microbial cell tube thus prepared was proved to be applicable for assay of L-threonine or L-serine in fermentation broth with rapidity (each assay, less than 9min), excellent substrate specificity (specific for L-threonine and L-serine) and high stability over repeated assays (at least 60 assays).