| The basic chiral units forming the protein is L-amino acid. People have made very profound and detailed research on L-amino acid, but know very little about its enantiomer D-amino acid. In fact, due to its significant features, D-amino acid has been extensively used to make antibiotics and physiological active peptide, and is playing an increasingly important role in medicine, foodstuff and agricultural chemicals. Up to now, most reports on the preparation method of D-amino acid are related to a specific variety, and there has been no special works about D-amino acid to give an overall description of its general development, nor have people performed systematic study on the preparation method of D-amino acid.In this connection, this paper contains a fairly complete description of the existence, application, preparation and development of D-amino acid, and on this basis, systematic research has been made on the optimum preparation method of D-amino acid ?chemical-enzyme method with regard to its versatility and high effectiveness, with overall description and actual application.This article describes the technical innovations as follows:The invention of internationally pioneering new process of synthesizing hydantoin under atmospheric pressure, with a mole yield of hydantoin (with respect to hydroxyl acetonitrile) of 86.2%, higher than that achieved using high pressure process (83%) as reported in foreign literature, and the hydantoin is in good quality. The technical parameters of the commercial plant sized 300 t/a have reached and surpassed the best levels reported both at home and overseas, and this process has been granted with intelligent property right.For the condensation-hydrogenation process to prepare 5-substituted hydantoin for use in the production of D-amino acid, exploitation has been made respectively to the condensation and hydrogenation reactions, and the optimum reaction conditions determined. The product yield is respectively 98.3% for 5-benzalhydantoin (as compared with 94% in literature), 92.6% for 5-(4-hydroxyl)benzalhydantoin (as compared with 86.28% in literature), and 83.8% for indolmethylenehydantoin (as compared with 84.9% in literature). The yield for hydrogenation is respectively 90.1% for 5-benzylhydantoin for 2 hours, 80.3% for 5-(4-hydroxyl)benzlhydantoin for 2 hours, and 70% for 5-indolymethyhydantoin for 5 hours. Among them, industrial production has been realized for the first time at home for 5-benzylhydantoin.For L or D, I-amino acid (such as Z,-Val, Z-Ala and D,L-Met), which is cheap and readily available, the annulation of amino acid is adopted to prepare the 5-substituted hydantoin, to produce 5-isopropylhydantoin, 5-methhylhydantoin and 5-methylthioemylhydantoin, with a yield of 94.5%, 93.0% and 96.2% respectively.For Burkholderia cepecia JS-01 strain, UV and 5-fluouracil combinedmutagenesis and laser mutagenesis have been made, with the product yield of D-phenylalanine converted from 5-benzylhydantoin as the sieve, to eventually obtain the single-stem strain Burkholderia cepecia 1003 at high conversion rate and stable characteristics, with a high conversion yield of D-phenylalanine of 85.5%. After a series of optimising experiments of fermentation, enzyme production and enzyme conversion, the optimum formulation for the strain fermentation culture medium and revellent and the most suitable conditions for enzyme conversion were determined.On this basis, six types of D-amino acid with optical pure: D-Phe, D-Tyr , D-Trp, D-Ala , D-Val and D-Met, have been synthesized using the racemic 5-substituted hydantoin, with the strain and synthesizing method described in this article. Among them, industrial production has been realized for Z)-Phe and pilot test completed for D-Trp, fully demonstrating the innovativeness, feasibility, versatility and advancement of the .methods described this article..The theoretical results of this article include:Research has been conducted on the enzyme system, enzyme chemical reaction principles and ch...
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