4.1.2.48	biotechnology	a continuous bioconversion system for L-threo-3,4-dihydroxyphenylserine production is developed that uses whole-cell biocatalyst of recombinant Escherichia coli expressing L-TA genes cloned from Streptomyces avelmitilis MA-4680. Maximum conversion rates are observed at 2 M glycine, 145 mM 3,4-dihydroxybenzaldehyde, 0.75% Triton-X, 5 g Escherichia coli cells/l, pH 6.5 and 10°C. In the optimized condition, overall productivity is 8 g/l	
4.1.2.48	pharmacology	biotechnological potential for the syntheses of pharmaceutically relevant drug molecules because of the stereospecificity	
4.1.2.48	synthesis	production of L-threo-3,4-dihydroxyphenylserine. At the optimized conditions, a mixture of L-threo-3,4-dihydroxyphenylserine and L-erythro-3,4-dihydroxyphenylserine is synthesized by diastereoselectivity-enhanced L-threonine aldolase expressed in Escherichia coli in a continuous process for 100 h, yielding an average of 4.0 mg/ml of L-threo-3,4-dihydroxyphenylserine and 60% diastereoselectivity	
4.1.2.48	synthesis	synthesis of optically active beta-hydroxy-alpha-amino acids by immobilized Escherichia coli cells expressing the enzyme. The immobilized cells can be continuously used 10 times, yielding an average conversion rate of 60.4%	
4.1.2.48	synthesis	the enzyme may be exploited for bioorganic synthesis of L-3-hydroxyamino acids that are biologically active or constitute building blocks for pharmaceutical molecules