Abstract: An economical and expedient method is disclosed for the preparation of &agr;-hydroxy-carboxylic acids or salts thereof in very high enantiomeric purity which comprises oxidizing a corresponding &agr;-amino-carboxylic acid or salt thereof using an amino acid deaminase followed by reducing the corresponding &agr;-keto-carboxylic acid or salt produced using a D- or L-lactate dehydrogenase in the combination with an electron donor and an enzyme/substrate system for recycling the electron donor. The resulting &agr;-hydroxy-carboxylic acids, hydrates, and salts thereof are valuable components and intermediates in the preparation of chiral compounds, especially pharmaceuticals. This invention also relates to the use of &agr;-amino-carboxylic acids, hydrates, and salts thereof and a coupled enzyme system in the production of &agr;-hydroxy-carboxylic acids, hydrates, and salts thereof.

Abstract: The regioselective and chemoselective hydrolysis of an .alpha.-ester group of an amino acid diester using pig liver esterase enzyme (PLE) is disclosed. The amino acid diesters may be either N-protected or unprotected and the diester groups may be the same or different. In particular, the preparation of a number of .gamma.-ester glutamates and .beta.-ester aspartates are provided.

Abstract: A process and composition for preparing D-aspartic acid and .beta.-alanine from D,L-aspartic acid, wherein a solution of D,L-aspartic acid or a salt thereof is contacted with a composition having an L-aspartate-.alpha.-decarboxylase activity of greater than 100 .mu.mol L-aspartate used per hour per gram of cells, under appropriate conditions to produce D-aspartic acid and .beta.-alanine.

Abstract: The regioselective and chemoselective hydrolysis of an .alpha.-ester group of an amino acid diester using pig liver esterase enzyme (PLE) is disclosed. The amino acid diesters may be either N-protected or unprotected and the diester groups may be the same or different. In particular, the preparation of a number of .gamma.-ester glutamates and .beta.-ester aspartates are provided.

Abstract: A novel method for the production of natural aromatic ester compounds such as methyl anthranilate, ethyl anthranilate butyl anthranilate methyl cinnamate and methyl salicylate comprises the esterification of their corresponding acids using microbially derived enzymes in the presence of a C.sub.1 -C.sub.4 alcohol such as methanol, ethanol or butanol. A biphasic reaction medium may optionally be utilized to generate maximum yields through the addition of a non-polar organic solvent such as hexane, ethyl acetate, heptane and the like.

Abstract: A modified hemicellulose A, hemicellulose B, modified hemicellulose A, modified hemicellulose B, or mixtures thereof are employed as water soluble bulking agents to replace the functional properties of carbohydrates or fats.