Process for the production of optically active 2-hydroxy acid esters using microbes to reduce the 2-oxo precursor

Abstract

An optically active 2-hydroxy acid derivative is produced by treating a 2-oxo acid derivative with a microorganism, which has been optionally treated, capable of asymmetrically reducing said 2-oxo acid derivative into an optically active (R)- or (S)-2-hydroxy acid derivative represented by the formula (II) and recovering the optically active (R)- or (S)-hydroxy acid derivative thus formed. Optically active 2-hydroxy acid derivatives are important intermediates in the synthesis of various drugs such as a remedy for hypertension.

Description

TECHNICAL FIELD

This invention relates to a process for the production of an optically active 2-hydroxy acid derivative, for example, an ester. More Particularly, it relates to a process for the production of an optically active 2-hydroxy acid derivative which comprises treating a 2-oxo acid derivative represented by the formula (I) with a microorganism, which has been optionally treated, capable of asymmetrically reducing said 2-oxo acid derivative of the formula (I) into an optically active (R)- or (S)-2-hydroxy acid derivative represented by the formula (II) and recovering the optically active (R)- or (S)-2-hydroxy acid derivative of the formula (II) thus formed.

Optically active 2-hydroxy acid derivatives represented by the formula (II) are important intermediates in the synthesis of various drugs, for example, a remedy for hypertension.

BACKGROUND ART

Known methods for the production of optically active ethyl 2-hydroxy-4-phenylbutyrate, which is one of 2-hydroxy acid derivatives represented by the formula (II), include chemical and asymmetric reduction of (R)-2-hydroxy-4-phenylbutyric acid (cf. Eur. Pat. EP 206993) and chemical synthesis comprising synthesizing (R)-2-hydroxy-4-phenylbutyric acid from benzylmagnesium chloride and optically active glycidic acid followed by ethyl-esterification (cf. Japanese Patent Laid-Open No. 212329/1987).

However the former method comprising the asymmetric chemical reduction cannot give a satisfactory optical purity of the product, while the latter one comprising the chemical synthesis is disadvantageous in that optically active serine, which is the starting material for the optically active glycidic acid, is expensive for industrial uses.

Furthermore, no process for the production of an optically active 2-hydroxy acid derivative represented by the formula (II) from a 2-oxo acid derivative represented by the formula (I) by taking advantage of the capability of asymmetric reduction of a microorganism has been reported so far.

DISCLOSURE OF INVENTION

The present inventors have paid attention to a process for conveniently producing an optically active 2-hydroxy acid derivative represented by the formula (II) having a high optical purity through asymmetric reduction with a microorganism and attempted to find out microorganisms suitable for the above purpose. As a result, they have found that microorganisms belonging to the genera Lactobacillus, Leuconostoc, Streptococcus, Pediococcus, Guilliermondella, Candida, Saccharomycopsis, Zygosaccharomyces, Sporidiobolus, Rhodosporidium, Saccharomyces, Shizosaccharomyces, Pichia, Issatchinkia, Rhodotorula, Kluyveromyces, Filobasidium, Torulaspora, Sporobolomyces, Hansenula, Lipomyces, Lodderomyces, Pachysolen, Saccharomycodes, Achromobacter, Brevibacterium, Erwinia, Klebsiella, Psudomonas, Bacillus and Xanthomonas could asymmetrically reduce a 2-oxo acid derivative represented by the formula (I) to thereby give an optically active (R)-2-hydroxy acid derivative represented by the formula (II); and that microorganisms belonging to the genera Lactobacillus, Leuconostoc, Streptococcus, Sporolactobacillus, Ambrosiozima, Botryoascus, Bretanomyces, Clavispora, Candida, Saccharomyces, Zygosaccharomyces, Schizosaccharomyces, Saccharomycopsis, Sporobolomyces, Rhodotorula, Pichia, Hansenula, Syringospora, Stephanoascus, Trigonopsis, Wickerhamiella, Winge, Schwanniomyces, Geotrichum, Ashybya, Endomyces, Alcaligenes, Escherichia, Serratia, Pseudomonas, Pimelobacter, Bacillus, Brevibacterium, Staphylococcus, Aureobacterium, Flavobacterium, Paracoccus, Citrobacter, Protaminobacter, Rhodococcus, Micrococcus, Agrobacterium, Corynebacterium, Mycobacterium and Proteus could asymmetrically reduce a 2-oxo acid derivative represented by the formula (I) to thereby give an optically active (S)-2-hydroxy acid derivative represented by the formula (II), thus completing the present invention.

The 2-oxo acid derivative to be used as the starting material in the present invention is represented by the formula (I). Examples thereof include methyl, ethyl, propyl and butyl esters of benzoylformic, phenylpyruvic, 2-oxo-4-phenylbutyric and 2-oxo-5-phenylvaleric acids.

In the present invention, any microorganism belonging to the genus Lactobacillus, Leuconostoc, Streptococcus, Pediococcus, Guilliermondella, Candida, Saccharomycopsis, Zygosaccharomyces, Sporidiobolus, Rhodosporidium, Saccharomyces, Schizosaccharomyces, Pichia, Issatchinkia, Rhodotorula, Kluyveromyces, Filobasidium, Torulaspora, Sporobolomyces, Hansenula, Lipomyces, Lodderomyces, Pachysolen, Saccharomycodes, Achromobacter, Brevibacterium, Torulopsis, Chromobacterium, Erwinia, Klebsiella, Pseudomonas, Bacillus or Xanthomonas and capable of asymmetrically reducing a 2-oxo acid derivative represented by the formula (I) into an optically active (R)-2-hydroxy acid derivative represented by the formula (II) or one belonging to the genus Lactobacillus, Leuconostoc, Streptococcus, Sporolactobacillus, Ambrosiozyma, Botryoascus, Bretanomyces, Clavispora, Candida, Saccharomyces, Zygosaccharomyces, Shizosaccharomyces, Saccharomycopsis, Sporobolomyces, Rhodotorula, Pichia, Hansenula, Syringospora, Stephanoascus, Trigonopsis, Wickerhamiella, Winge, Schwanniomyces, Geotrichum, Ashybya, Endomyces, Alcaligenes, Escherichia, Serratia, Pseudomonas, Pimelobacter, Bacillus, Bacterium, Brevibacterium, Staphylococcus, Aureobacterium, Flavobacterium, Paracoccus, Citrobacter, Protaminobacter, Rhodococcus, Micrococcus, Agrobacterium, Corynebacterium, Mycobacterium or Proteus and capable of asymmetrically reducing a 2-oxo acid derivative represented by the formula (I) into an optically active (S)-2-hydroxy acid derivative represented by the formula (I) may be used.

Particular examples of the microorganism capable of producing an optically active (R)-2-hydroxy acid derivative represented by the formula (II) from a 2-oxo acid derivative represented by the formula (I) include Lactobacillus acidophilus NRIC1027 and IFO3831, Lactobacillus buchneri NRIC1027 and ATCC4005, Lactobacillus brevis IFO3960, Lactobacillus casei subsp. casei IFO12004, Lactobacillus cellobiosus NRIC1047 and ATCC11739, Lactobacillus collinoides NRIC1049 and ATCC27611, Lactobacillus coryniformis NRIC1051 and ATCC25600, Lactobacillus curvatus NRIC1052 and ATCC25601, Lactobacillus frigidus NRIC1079 and ATCC11307, Lactobacillus hilgardii NRIC1060 and ATCC 8290, Lactobacillus lactis NRIC1061 and ATCC123315, Lactobacillus malefermentas NRIC1081, Lactobacillus parvus NRIC1082 and ATCC11305, Lactobacillus sake NRIC1071 and ATCC15521, Lactobacillus salivarius NRIC1072 and ATCC11742, Lactobacillus vaccinistercus NRIC1075 and ATCC33310, Leuconostoc citrovorum NRIC1089, Leuconostoc cremoris NRIC1083 and ATCC19254, Leuconostoc dextranicum NRIC1085 and ATCC19255, Leuconostoc mesenteroides subsp. dextranicum IFO3349, Leuconostoc mesenteroides NRIC1088 and ATCC27307, Leuconostoc mesenteroides subsp. mesenteroides IFO3426, Streptococcus alactosus NRIC1154 and ATCC8058, Streptococcus equinus NRIC1139 and ATCC9812, Streptococcus faecium NRIC1145 and ATCC19434, Streptococcus uberis NRIC1153 and ATCC19436, Pediococcus parvulus IFO12233, Pediococcus pentosaceus IFO3891, Pediococcus sacidilactici ATCC8081, Gullliermondella selenospora IFO1850, Candida guilliermondii IAM4412, Saccharomycopsis fibuligera IFO0103, Saccharomycopsis capsularis IFO0672, Zygosaccharomyces bailii IFO1047, Sporidiobolus pararoseus AHU3447, Rhodosporidium diobovatum IFO0682, Rhodosporidium toruloides IFO0559, Saccharomyces rouxii IAM4011, Saccharomyces dairensis IFO0285, Torulaspora delbrueckii IFO0955, Schizosaccharomuyces pombe IFO0363, Pichia heedil IFO10019, Pichia membranaefaciens IFO0577, Pichia opuntiae var. thermotolerans IFO10024, Issatchinkia scutulata var scutulata IFO10069, Rhodotorula rubra AHU3243, Rhodotorula glutinis AHU3454, Kluyveromyces lactis IFO1267, Kluyveromyces drosphilarum IFO1012, Filobasidium capsuligenum IFO1185, Torulaspora delbrueckii IFO0381, Sporobolomyces rosenus IFO1037, Hansenula holsttii IFO0980, Hansenula subpelliculosa IFO0808, Sporidiobolus johnsonii IFO6903, Lipomyces starkeyi IFO1289, Lodderomyces elongisporus IFO1676, Pachysolen tannophilus IFO1007, Saccharomycodes ludwigii IFO0798, Achromobacter pestifer ATCC23584, Brevibacterium iodinum IFO3558, Erwinia carotovora IFO3880, Klebsiella pneumoniae IAM1063, Pseudomonas dacunhae IFO12048, Bacillus licheniformis IFO12200, Bacillus cereus IFO3001 and Xanthomonas oryzae IAM1657.

Examples of the microorganism capable of producing an optically active (S)-2-hydroxy acid derivative represented by the formula (II) from a 2-oxo acid derivative represented by the formula (I) include Lactobacillus brevis NRIC1037 and ATCC4006, Lactobacillus bulgaricus NRIC1041 and IAM1120, Lactobacillus casei NRIC1044 and ATCC25598, Lactobacillus casei subsp. rhamnosus IFO3425, Lactobacillus fructosus NRIC1058 and ATCC12315, Lactobacillus delbrueckii AHU1056, Lactobacillus leichmannii AHU1681, Lactobacillus paintatum IFO3070, Lactobacillus viridescens NRIC1073 and ATCC12706, Lactobaciilus xylosus NRIC1074 and ATCC15577, Lactobacillus yamanashiensis NRIC1076 and ATCC27304, Leuconosotc mesenteroides AHU1067, Leuconostoc dextranicum AHU1080, Streptococcus agalactiae NRIC1137 and ATCC13813, Streptococcus lactis NRIC1149 and ATCC19435, Streptococcus faecalis IFO12964, Sporolactobacillus inulinus NRIC1133 and ATCC15538, Ambrosiozyma cicatricosa IFO1846, Botryoascus synnaedendrus IFO1604, Bretanomyces bruxellensis IFO0268, Clavispora lusitaniae IFO1019, Candida humicola IFO0760, Candida parasilosis IFO1396, Candida pseudotropicalis IAM4829, Candida utilis IAM4220, Candida rugosa IFO0750, Saccharomyces bayanus IFO0262, Saccharomyces cerevisiae ATCC9080, Saccharomyces kluyveri IFO1893, Saccharomyces uvarum IFO0565, Saccharomyces chevalieri IFO0222, Zygosaccharomyces fermentati IFO0021, Shizosaccharomyces octosporus IFO0353, Saccharomycopsis lipolytica IFO1551, Sporobolomyces salmonicolor AHU3982, Rhodotolura glutinis IFO0389, Rhodotorula minuta IFO0387, Pichia opuntiae var. thermotolerans IFO10025, Pichia burtonii IFO1986, Pichia farinosa IFO1163, Hansenula fabianii IFO1254, Syringospora albicans IFO1856, Stephanoascus ciferrii IFO1854, Trigonopsis variabilis IFO0755, Wickerhamiella domercqii IFO1857, Wingea robertsii IFO1277, Schwanniomyces occidentalis IFO1841, Geotrichum candidum IFO4601, Ashbya gossypii IFO1355, Endomyces decipiens IFO0102, Alcaligenes faecalis IAM1015, Esherichia coli IFO3544, Serratia marcescens IFO3046, Pseudomonas aureofaciens IFO3522, Pseudomonas fluorescens IFO3925, Pseudomonas riboflavina IFO13584, Pseudomonas chlororaphis IFO3904, Pimelobacter simplex IFO12069, Bacillus subtilis IFO3007, Brevibacterium ammoniagenes IAM1641, Staphylococcus aureus IFO 3060, Aureobacterium testaceu IFO12675, Flavobacterium suaveolens IFO3752, Paracoccus denitrificans IFO12442, Citrobacter freundii AHU1534, Protaminobacter ruber IAM1081, Rhodococcus equil IFO3730, Micrococcus luteus IFO12992, Agrobacterium radiobacter IFO12664, Corynebacterium glutamicum ATCC13032, Mycobacterium smegmatis IFO3153 and Proteus vulgaris IFO3851.

Each strain may be either a wild type, a variant or a recombinant obtained by genetic engineering such as cell fusion or gene recombination.

Microorganisms having IFO numbers assigned thereto are described in the List of Culture, 8th ed., vol. 1 (1988) published by the Institute for Fermentation, Osaka (IFO) and available therefrom. Those having AHU numbers are described in the Catalogue Culture, 4th ed. (1987) published by Japan Federation of Culture Collection (JFCC) and available from the Faculty of Agriculture, Hokkaido University. Those having ATCC numbers are described in the Catalogue of Bacteria phages rDNA Vectors, 16th ed. (1985) published by American Type Culture Collection (ATCC) and available therefrom. Those having NRIC numbers are described in the Culture Collection of NODAI No. 1 (1985) published by Tokyo University of Agriculture and available therefrom. Those having IAM numbers are available from the Institute of Applied Microbiology, the University of Tokyo.

The microorganism to be used in the present invention may be cultured in any medium so long as it can grow therein. Any carbon source may be used so long as said microorganism can utilize it. Examples thereof include sugars such as glucose, fructose, sucrose and dextrin, alcohols such as sorbitol, ethanol and glycerol, organic acids such as fumaric, citric, acetic and propionic acids and salts thereof, hydrocarbons such as paraffin and mixtures thereof. Examples of a nitrogen source include ammonium salts of inorganic acids, such as ammonium chloride, ammonium sulfate and ammonium phosphate, ammonium salts of organic acids, such as ammonium fumarate and ammoniumcitrate, nitrogenous materials such as meat extract, yeast extract, corn steep liquor, casein hydrolysate and urea and mixtures thereof. Furthermore various nutritional sources commonly used in the culture of microorganisms, such as inorganic salts, trace metal salts and vitamins, may be appropriately mixed and used in the present invention. In addition, materials effective in promoting the growth of the microorganism, in elevating the productivity of the target compound or in maintaining the pH value of the medium on the desired level may be added, if required.

The pH value of the medium may be adjusted to 3.0 to 9.5, preferably 5 to 8. The culture may be carried out at a temperature of 20.degree. to 45.degree. C., preferably 25.degree. to 37.degree. C., either aerobically or anaerobically under conditions suitable for the growth of the microorganism for 15 to 120 hours, preferably 12 to 72 hours.

The reduction may be effected by using the culture medium as such. Alternately, the cells may be separated by, for example, centrifugation, optionally washed and resuspended in a buffer solution or water. Then a 2-oxo acid derivative represented by the formula (I) may be added to the suspension thus obtained. In this reaction, it is sometimes preferable to add a carbon source such as glucose or sucrose to the medium to thereby supply energy. The cells may be used as such in the form of viable cells. Alternately, they may be ground, treated with acetone or lyophilized. These cells, which have been optionally treated, may be immobilized prior to the use by a conventional method such as the polyacrylamide gel, carrageenan gel, alginic acid gel or agar gel method. Furthermore, an enzyme obtained from said treated cells by combining known methods may be used in the present invention.

The 2-oxo acid derivative represented by the formula (I) may be added either at once at the initiation of the reaction or by portions either as such, dissolved in water or an inert organic solvent or dispersed in, for example, a surfactant.

The reaction may be conducted at a pH value of 3 to 9, preferably 5 to 8, at 10.degree. to 60.degree. C., preferably 20.degree. to 40.degree. C. for 1 to 120 hours with or without stirring. The concentration of the substrate may preferably range from 0.1 to 10%, though it is not restricted thereby.

The optically active (R)- or (S)-2-hydroxy acid derivative represented by the formula (II) thus produced may be readily collected by extracting the reaction mixture, from which the cells may be optionally separated, with an organic solvent and purifying the extract by, for example, column chromatography or recrystallization.

BEST MODE FOR CARRYING OUT THE INVENTION

To further illustrate the present invention, and not by way of limitation, the following Examples will be given.

In each Example, the absolute configuration and optical purity were determined by extracting the reaction product with ethyl acetate and subjecting the obtained extract to high performance liquid chromatography by using an optical resolution column Column: Chiral cell OB, mfd. by Daicel Chemical Industries, Ltd., 4.6 mm (i.d.).times.250 mm, solvent: n-hexane : 2-propanpol (19 : 1 v/v), flow rate: 0.5 ml/min, Detection: 254 nm]. The reaction yield was determined by gas chromatography [column: PEG20M, 10%, 2 m, 200.degree. C.].

EXAMPLE 1

100 ml of a medium comprising 2% of glucose, 0.5% of yeast extract, 0.3% of peptone, 0.3% of meat extract, 0.1% of monopotassium phospate, 0.2% of dipotassium phosphate and 0.5% of calcium carbonate was introduced into a 500-ml Erlenmeyer flask and sterilized. Next, each strain specified in Table 1 was inoculated thereto and cultured therein at 30.degree. C. for 30 hours under rotation and shaking.

After the completion of the culture, the cells were separated by centrifugation and washed once with a physiological saline solution to thereby give viable cells.

7.5 ml of distilled water was introduced into a 100-ml Erlenmeyer flask and the above viable cells were suspended therein. 1.2 g of glucose was added to the suspension thus obtained and the resulting mixture was shaken under rotation at 30.degree. C. for 10 minutes. Then 0.1 g of ethyl 2-oxo-4-phenylbutyrate and 0.3 g of calcium carbonate were added thereto and the resulting mixture was shaken under rotation at 30.degree. C. for 20 hours.

After the completion of the reaction, the optically active ethyl 2-hydroxy-4-phenylbutyrate thus formed was extracted with 20 ml of ethyl acerate.

The ethyl acetate phase was analyzed by gas chromatography and the reaction yield was determined. Next, a given amount of the ethyl acetate phase was dehydrated with anhydrous Glauber's salt and the solvent was removed therefrom. The oily product thus obtained was dissolved in ethanol and subjected to high performance liquid chromatography. The absolute configuration and optical purity of the optically active ethyl 2-hydroxy-4-phenylbutyrate thus obtained were determined.

Table 1 shows the results.

EXAMPLE 2

100 ml of a YM medium comprising 0.3% of yeast extract, 0.3% of malt extract, 0.5% of peptone and 2% of glucose (pH 6.0) was introduced into a 500-ml Sakaguchi flask and sterilized. Then each strain specified in Table 2 was inoculated thereto and cultured therein at 30.degree. C. for 48 hours under shaking.

After the completion of the culture, the cells were separated by centrifugation and washed once with a physiological saline solution to thereby give viable cells.

50 ml of distilled water was introduced into a 500-ml Sakaguchi flask and the abovementioned viable cells were suspended therein. Then 6 g of sucrose was added to the obtained suspension and the mixture was reciprocally shaken at 30.degree. C. for 10 minutes. Next, 0.5 g of ethyl 2-oxo-4-phenylbutyrate was added thereto and the resulting mixture was reciprocally shaken at 30.degree. C. for 20 hours.

After the completion of the reaction, the reaction yield, absolute configuration and optical purity of the optically active ethyl 2-hydroxy-4-phenylbutyrate thus obtained were determined in the same manner as the one described in Example 1.

Table 2 shows the results.

EXAMPLE 3

Each microorganism specified in Table 3 was subjected to the same treatment as that described in Example 1 except that the medium contained no calcium carbonate and had a pH value of 7 and that the culture was reciprocally conducted in a 500-ml Sakaguchi flask.

After the completion of the reaction, the reaction yield, absolute configuration and optical purity of the optically active ethyl 2-hydroxy-4-phenylbutyrate thus obtained were determined in the same manner as the one described in Example 1.

Table 3 shows the results.

EXAMPLE 4

Leuconostoc mesenteroides subsp. dextranicum IFO3349 was inoculated into 2-l of the same medium as the one described in Example 2 in a 5-l jar fermenter and cultured therein at 30.degree. C. under stirring at 100 rpm for 30 hours.

After the completion of the culture, the cells were collected by centrifugation and washed with 1-l of water. Then these cells were suspended in 200 ml of water and introduced into a 1-l Erlenmeyer flask. Next, 2 g of ethyl 2-oxo-4-phenylbutyrate, 20 g of glucose and 2 g of calcium carbonate were added thereto and the obtained mixture was allowed to react at 30.degree. C. under stirring for 48 hours.

After the completion of the reaction, the reaction mixture was extracted with 100-ml portions of ethyl acetate twice. The ethyl acetate phase was dehydrated with anhydrous Glauber's salt and the solvent was removed therefrom under reduced pressure. Then it was distilled in a conventional manner under reduced pressure of 0.5 mmHg (b.p.: 115.degree.-118.degree. C.). Thus 1.4 g of the aimed ethyl (R)-2-hydroxy-4-phenylbutyrate was obtained (yield: 70%, optical purity: 82% e.e.).

EXAMPLE 5

Pseudomonas aureofaciens IFO3522 was inoculated into 2-l of the same medium as the one described in Example 1 except containing no calcium carbonate in a 5-l jar fermenter and cultured therein at 30.degree. C. under stirring at 4.00 rpm and aerating at 1 vvm for 30 hours.

After the completion of the culture, the cells were collected by centrifugation and washed with 1-l of water. Then these cells were suspended in 200 ml of water and introduced into a 1-l Erlenmeyer flask. Twenty g of ethyl 2-oxo-4-phenylbutyrate, 20 g of glucose and 2 g of calcium carbonate were added thereto and the obtained mixture was allowed to react at 30.degree. C. under stirring for 48 hours.

After the completion of the reaction, the reaction mixture was extracted with 100-ml portions of ethyl acetate twice. The ethyl acetate phase was dehydrated with anhydrous Glauber's salt and the solvent was removed therefrom under reduced pressure. Then it was distilled in a conventional manner under reduced pressure of 0.5 mmHg (b.p.: 115.degree.-118.degree. C.). Thus 0.7 g of the aimed ethyl (S)-2-hydroxy-4-phenylbutyrate was obtained (yield: 35%, optical purity: 96% e.e.).

The process of the present invention for the production of an optically active 2-hydroxy acid derivative through asymmetric reduction by using a microorganism makes it possible to readily produce an optically active 2-hydroxy acid derivative having a high optical purity. Thus it is highly advantageous as an industrial process.

TABLE 1______________________________________ Optically active ethyl 2-hydroxy- 4-phenylbutyrate Absolute Optical Yield config- purityMicroorganism (%) uration (% e.e.)______________________________________Lactobacillus acidophilus 10 R 61NRIC1027Lactobacillus buchneri 12 R 54NRIC1040Lactobacillus brevis 8 R 100IFO3960Lactobacillus casei 16 R 100subsp. caseiIFO12004Lactobacillus cellobiosus 11 R 53NRIC1047Lactobacillus collinoides 12 R 60NRIC1049Lactobacillus coryniformis 13 R 33NRIC1051Lactobacillus curvatus 13 R 56NRIC1052Lactobacillus frigidus 12 R 57NRIC1079Lactobacillus hilgardii 13 R 39NRIC1060Lactobacillus lactis 96 R 49NRIC1061Lactobacillus malefermentans 13 R 61NRIC1081Lactobacillus parvus 73 R 22NRIC1082Lactobacillus sake 14 R 24NRIC1071Lactobacillus salivarius 13 R 58NRIC1072Lactobacillus vaccinistercus 13 R 45NRIC1075Leuconostoc citrovorum 77 R 35NRIC1089Leuconostoc cremoris 12 R 57NRIC1083Leuconostoc dextranicum 17 R 24NRIC1085Leuconostoc mesenteroides 45 R 74subsp. dextranicumIFO3349Leuconostoc mesenteroides 21 R 25NRIC1088Leuconostoc mesenteroides 27 R 20subsp. mesenteroidesIFO3426Streptococcus alactosus 10 R 25NRIC1154Streptococcus equinus 12 R 91NRIC1139Streptococcus faecium 93 R 53Streptococcus uberis 80 R 40NRIC1153Pediococcus parvulus 18 R 20IFO12233Pediococcus pentosaceus 39 R 22IFO3891Pediococcus acidilactici 56 R 37ATCC8081Lactobacillus brevis 59 S 65NRIC1037Lactobacillus bulgaricus 13 S 20NRIC1041Lactobacillus casei 36 S 20NRIC1044Lactobacillus casei 35 S 20subsp. rhamnosusIFO3425Lactobacillus fructosus 12 S 50NRIC1058Lactobacillus delbrueckii 37 S 20AHU1056Lactobacillus leichmannii 44 S 40AHU1681Lactobacillus plantarum 30 S 96IFO3070Lactobacillus viridescens 55 S 72NRIC1073Lactobacillus xylosus 59 S 20NRIC1074Lactobacillus yamanashiensis 13 S 33NRIC1076Leuconostoc mesenteroides 15 S 84AHU1067Leuconostoc dextranicum 19 S 20AHU1080Streptococcus agalactiae 95 S 68NRIC1137Streptococcus lactis 26 S 76NRIC1149Streptococcus faecalis 33 S 85IFO12964Sporolactobacillus inulinus 10 S 91NRIC1133______________________________________ TABLE 2______________________________________ Optically active ethyl 2-hydroxy- 4-phenylbutyrate Absolute Optical Yield config- purityMicroorganism (%) uration (% e.e.)______________________________________Guilliermondella selenospora 10 R 20IFO1850Candida guilliermondii 16 R 40IAM4412Saccharomycopsis fibuligera 10 R 22IFO0103Saccharomycopsis capsularis 10 R 20IFO0672Zygosaccharomyces bailii 23 R 20IFO1047Sporidiobolus pararoseus 25 R 99AHU3447Rhodosporidium diobovatum 42 R 72IFO0682Rhodosporidium toruloides 10 R 100IFO0559Saccharomyces rouxii 14 R 78IAM4011Saccharomyces dairensis 29 R 42IFO0285Torulaspora delbrueckii 58 R 20IFO0955Schizosaccharomyces pombe 34 R 20IFO0363Pichia heedii 21 R 69IFO10019Pichia membranaefaciens 47 R 33IFO0577Pichia opuntiae 35 R 20var. thermotoleransIFO10024Issatchinkia scutulata 26 R 56var. scutulataIFO10069Rhodotorula rubra 23 R 57AHU3243Rhodotorula glutinis 41 R 48AHU3454Kluyveromyces lactis 43 R 32IFO1267Kluyveromyces drosophilarum 45 R 20IFO1012Filobasidium capsuligenum 8 R 46IFO1185Torulaspora delbrueckii 70 R 45IFO0381Sporobolomyces roseus 11 R 62IFO1037Hansenula holsttii 27 R 32IFO0980Hansenula subpelliculosa 32 R 34IFO0808Sporidiobolus johnsonii 51 R 22IFO6903Lipomyces starkeyi 10 R 24IFO1289Lodderomyces elongisporus 52 R 26IFO1676Pachysolen tannophilus 26 R 20IFO1007Saccharomycodes ludwigii 10 R 21IFO0798Ambrosiozyma cicatricosa 11 S 46IFO1846Botryoascus synnaedendrus 16 S 19IFO1604Bretanomyces bruxellensis 19 S 20IFO0628Clavispora lusitaniae 31 S 30IFO1019Candida humicola 10 S 26IFO0760Candida parapsilosis 50 S 20IFO1396Candida pseudotropicalis 10 S 62IAM4829Candida utilis 35 S 53IAM4220Candida rugosa 21 S 71IFO0750Saccharomyces bayanus 96 S 43IFO0262Saccharomyces cerevisiae 15 S 32ATCC9080Saccharomyces kluyveri 35 S 65IFO1893Saccharomyces uvarum 20 S 33IFO0565Saccharomyces chevalieri 96 S 40IFO0222Zygosaccharomyces fermentati 32 S 20IFO0021Schizosaccharomyces octosporus 26 S 40IFO0353Saccharomycopsis lipolytica 10 S 61IFO1551Sporobolomyces salmonicolor 45 S 20AHU3982Rhodotorula glutinis 10 S 37IFO0389Rhodotolura minuta 10 S 20IFO0387Pichia opuntiae 10 S 34var. thermotoleransIFO10025Pichia burtonii 12 S 71IFO1986Pichia farinosa 20 S 67IFO1163Hansenula fabianii 43 S 36IFO1254Syringospora albicans 58 S 32IFO1856Stephanoascus ciferrii 12 S 48IFO1854Trigonopsis variabilis 25 S 69IFO0755Wickerhamiella domercqii 63 S 41IFO1857Wingea robertsii 19 S 42IFO1277Schwanniomyces occidentalis 17 S 31IFO1841Geotrichum candidum 34 S 28IFO4601Ashbya gossypii 37 S 100IFO1355Endomyces decipiens 32 S 100IFO0102______________________________________ TABLE 3______________________________________ Optically active ethyl 2-hydroxy- 4-phenylbutyrate Absolute Optical Yield config- purityMicroorganism (%) uration (% e.e.)______________________________________Achromobacter pestifer 14 R 100ATCC23584Brevibacterium iodinum 30 R 62IFO3558Erwinia carotovora 11 R 100IFO3830Klebsiella pneumoniae 12 R 100IAM1063Pseudomonas dacunhae 13 R 100IFO12048Bacillus licheniformis 11 R 100IFO12200Bacillus cereus 12 R 21IFO3001Xanthomonas oryzae 37 R 20IAM1657Alcaligenes faecalis 24 S 97IAM1015Esherichia coli 34 S 94IFO3544Serratia marcescens 40 S 89IFO3046Pseudomonas aureofaciens 36 S 95IFO3522Pseudomonas fluorescens 49 S 54IFO3925Pseudomonas riboflavina 12 S 56IFO13584Pseudomonas chlororaphis 46 S 76IFO3904Pimelobacter simplex 11 S 100IFO12069Bacillus subtilis 15 S 71IFO3007Brevibacterium ammoniagenes 18 S 80IAM1641Staphylococcus aureus 23 S 85IFO3060Aureobacterium testaceum 41 S 62IFO12675Flavobacterium suaveolens 23 S 85IFO3752Paracoccus denitrificans 11 S 74IFO12442Citrobacter freundii 18 S 56AHU1534 Protaminobacter ruber 21 S 43IAM1081Rhodococcus equii 11 S 100IFO3730Micrococcus luteus 10 S 24IFO12992Agrobacterium radiobacter 16 S 35IFO12664Corynebacterium glutamicum 54 S 20ATCC13032Mycobacterium smegmatis 15 S 21IFO3153Proteus vulgaris 12 S 30IFO3851______________________________________

Claims

1. A process for the production of an optically active 2-hydroxy acid derivative represented by the formula (II): ##STR1## wherein X.sub.1 and X.sub.2 represent each a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group or an alkyl group, R represents an alkyl or a phenyl group, and n is an integer ranging from 0 to 3,

which comprises treating a 2-oxo acid derivative represented by the formula (I): ##STR2## wherein X.sub.1, X.sub.2, R and n are as previously defined, with a microorganism capable of asymmetrically reducing said 2-oxo acid derivative of the formula (I) into an optically active (R)-form of said 2-hydroxy acid derivative of the formula (II) , wherein said microorganism is selected from the group consisting of:

Sporidiobolus pararoseus;

Rhodosporidium toruloides;

Lactobacillus casei;

Leuconostoc mesenteroides subsp. dextranicum; and

Streptococcus equinus;

and recovering the optically active (R)-2-hydroxy acid derivative of the formula (II) so produced.

2. A process for the production of an optically active 2-hydroxy acid derivative represented by the formula (II): ##STR3## wherein X.sub.1 and X.sub.2 represent each a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group or an alkyl group, R represents an alkyl or a phenyl group, and n is an integer ranging from 0 to 3,

which comprises treating a 2-oxo acid derivative represented by the formula (I): ##STR4## wherein X.sub.1, X.sub.2, R and n are as previously defined, with a microorganism capable of asymmetrically reducing said 2-oxo acid derivative of the formula (I) into an optically active (S)-form of said 2-hydroxy acid derivative of the formula (II), wherein said microorganism is selected from the group consisting of:

Lactobacillus plantarum;

Ashbya gossypii;

Serratia marcescens;

Esherichia coli;

Pseudomonas aureofaciens;

Leuconostoc mesenteroides;

Streptococcus faecalis;

Sporolactobacillus inulinus;

Candida rugosa;

Pichia burtonii;

Trigonopsis variabilis;

Flavobacterium suaveolens; and

Paracoccus denitrificans;

and recovering the optically active (S)-2-hydroxy acid derivative of the formula (II) so produced.

3. A process for the production of an optically active 2-hydroxy acid derivative represented by the formula (II): ##STR5## wherein X.sub.1 and X.sub.2 represent each a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group or an alkyl group, R represents an alkyl or a phenyl group, and n is an integer ranging from 0 to 3, which comprises treating a 2-oxo acid derivative represented by the formula (I): ##STR6## wherein [X.sub.1 and X.sub.2 represent each a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group or an alkyl group, R represents an alkyl or a phenyl group, and n is an integer ranging from 0 to 3,]X.sub.1, X.sub.2, R and n are as previously defined,

with a microorganism capable of asymmetrically reducing said 2-oxo acid derivative of the formula (I) into an optically active (R) form of said 2-hydroxy acid derivative of the formula (II) , wherein said microorganism is selected from the group consisting of:

______________________________________Lactobacillus casei [IF012004] IFO 12004Leuconostoc mesenteroides [IF03349] IFO 3349subsp. dextranicumRhodosporidium toruloides [IF00559] IFO 0559[Saccharomyces rouxii IAM4011]______________________________________

and recovering the optically active (R)-2-hydroxy acid derivative of the formula (II) so produced.

4. A process as in claim 3, wherein said 2-oxo acid derivative to be used as the starting material is selected from the group consisting of methyl, ethyl, propyl, and butyl esters of benzoylformic, phenylpyruvic, 2-oxo-4-phenylbutyric and 2-oxo-5-phenylvaleric acids.

5. A process as in claim 3, wherein said 2-oxo acid derivative used as the starting material is the ethyl ester of 2-oxo-4-phenylbutyric acid.

6. The process of claim 3, wherein said microorganism has been collected from the culture and resuspended in an aqueous medium prior to treating the said 2-oxo acid.

7. The process of claim 3, wherein said microorganism has been collected from the culture and the cells are ground, treated with acetone, or lyophilized prior to treating the said 2-oxo acid.

8. A process for the production of an optically active 2-hydroxy acid derivative represented by the formula (II): ##STR7## wherein X.sub.1 and X.sub.2 represent each a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group or an alkyl group, R represents an alkyl or a phenyl group, and n is an integer ranging from 0 to 3,

which comprises treating a 2-oxo acid derivative represented by the formula ( I ): ##STR8## wherein X.sub.1, X.sub.2, R and n are as previously defined, with a microorganism capable of asymmetrically reducing said 2-oxo acid derivative of the formula (I) into an optically active (S)-form of said 2-hydroxy acid derivative of the formula (II), wherein said microorganism is selected from the group consisting of:

______________________________________Lactobacillus plantarum [IF03070] IFO 3070Leuconostoc mesenteroides [AHU1067] AHU 1067Streptococcus faecalis [IF012964] IFO 12964Sporolactobacillus inulinus [NRIC1133] NRIC 1133[Candida pseudotropicalis IAM4829]Candida rugosa [IF00750] IFO 0750Pichia burtonii [IF01986] IFO 1986Trigonopsis variabilis [IF00755] IFO 0755Ashbya gossypii [IF01355] IFO 1355[Endomyces decipiens IF00102]Esherichia coli [IF03544] IFO 3544Serratia marcescens [IF03046] IFO 3046Pseudomonas aureofaciens [IF03522] IFO 3522 and[Brevibacterium ammoniagenes JAM1641]______________________________________

and recovering the optically active (S)-2-hydroxy acid derivative of the formula (II) so produced.

9. A process as in claim 8, wherein said 2-oxo acid derivative to be used as the starting material is selected from the group consisting of methyl, ethyl, propyl, and butyl esters of benzoylformic, phenylpyruvic, 2-oxo-4-phenylbutyric and 2-oxo-5-phenylvaleric acids.

10. A process as in claim 8, wherein said 2-oxo acid derivative used as the starting material is the ethyl ester of 2-oxo-4-phenyl butyric acid.

11. The process of claim 8, wherein said microorganism has been collected from the culture and resuspended in an aqueous medium prior to treating the said 2-oxo acid.

12. The process of claim 8, wherein said microorganism has been collected from the culture and the cells ground, treated with acetone, or lyophilized prior to treating the said 2-oxo acid.

13. A process for the production of an optically active 2-hydroxy acid derivative represented by the formula (II): ##STR9## wherein X.sub.1 and X.sub.2 represent each a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group or an alkyl group, R represents an alkyl or a phenyl group, and n is an integer ranging from 0 to 3,

which comprises treating a 2-oxo acid derivative represented by the formula (I): ##STR10## wherein X.sub.1, X.sub.2, R and n are as previously defined, with a microorganism capable of asymmetrically reducing said 2-oxo acid derivative of the formula (I) into an optically active (R)- form of said 2-hydroxy acid derivative of the formula (II), wherein said microorganism is selected from the group consisting of:

______________________________________Streptococcus equinus [NRIC1139] NRIC 1139Sporidiobolus pararoseus [AHU3447] AHU 3447Rhodosporidium toruloides [IF00559] IFO 0559 and[Saccharomyces rouxii IAM4011]______________________________________

and recovering the optically active (R)-2-hydroxy acid derivative of the formula (II) so produced.

14. A process for the production of an optically active 2-hydroxy acid derivative represented by the formula (II): ##STR11## wherein X.sub.1 and X.sub.2 represent each a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group or an alkyl group, R represents an alkyl or a phenyl group, and n is an integer ranging from 0 to 3,

which comprises treating a 2-oxo acid derivative represented by the formula (I): ##STR12## wherein X.sub.1, X.sub.2 , R and n are as previously defined, with a microorganism capable of asymmetrically reducing said 2-oxo acid derivative of the formula (I) into an optically active (S)-form of said 2-hydroxy acid derivative of the formula (II), wherein said microorganism is selected from the group consisting of:

______________________________________Streptococcus faecalis [IF012964] IFO 12964Sporolactobacillus inulinus [NRIC1133] NRIC 1133[Candida pseudotropicalis IAM4829]Candida rugosa [IF00750] IFO 0750Pichia burtonii [IF01986] IFO 1986Trigonopsis variabilis [IF00755] IFO 0755Ashbya gossypii [IF01355] lFO 1355[Endomyces decipiens IF00102]Esherichia coli [IF03544] IFO 3544Serratia marcescens [IF03046] IFO 3046Pseudomonas aureofaciens [IF03522] IFO 3522[Pseudomonas fluorescens IF03925][Brevibacterium ammoniagenes IAM1641]Flavobacterium suaveolens [IF03752] IFO 3752 andParacoccus denitrificans [IF012442] IFO 12442______________________________________

and recovering the optically active (S)-2-hydroxy acid derivative of the formula (II) so produced.

15. A process for the production of an optically active 2-hydroxy acid derivative represented by the formula (II): ##STR13## wherein X.sub.1 and X.sub.2 represent each a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group or an alkyl group, R represents an alkyl or a phenyl group, and n is an integer ranging from 0 to 3,

which comprises treating a 2-oxo acid derivative represented by the formula (I): ##STR14## wherein X.sub.1, X.sub.2, R and n are as previously defined, with a microorganism capable of asymmetrically reducing said 2-oxo acid derivative of the formula (I) into an optically active (R)-form of said 2-hydroxy acid derivative of the formula (II), wherein said microorganism is selected from the group consisting of:

______________________________________Lactobacillus casei [IF012004] IFO 12004subsp. caseiLeuconostoc mesenteroides [IF03349] IFO 3349subsp. dextranicumStreptococcus equinus [NRIC1139] NRIC 1139Sporidiobolus pararoseus [AHU3447] AHU 3447Rhodosporidium toruloides [IF00559] IFO 0559 and[Saccharomyces rouxii IAM4011]______________________________________

and recovering the optically active (R)-2-hydroxy acid derivative of the formula (II) so produced.

16. The process of claim 15, wherein said microorganism has been collected from the culture and resuspended in an aqueous medium prior to treating the said 2-oxo acid.

17. The process of claim 15, wherein said microorganism has been collected from the culture and the cells ground, treated with acetone, or lyophilized prior to treating the said 2-oxo acid.

18. A process for the production of an optically active 2-hydroxy acid derivative represented by the formula (II): ##STR15## wherein X.sub.1 and X.sub.2 represent each a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group or an alkyl group, R represents an alkyl or a phenyl group, and n is an integer ranging from 0 to 3,

which comprises treating a 2-oxo acid derivative represented by the formula (I): ##STR16## wherein X.sub.1, X.sub.2, R and n are as previously defined, with a microorganism capable of asymmetrically reducing said 2-oxo acid derivative of the formula (I) into an optically active (S)-form of said 2-hydroxy acid derivative of the formula (II), wherein said microorganism is selected from the group consisting of:

______________________________________Lactobacillus plantarum [IF03070] IFO 3070Streptococcus faecalis [IF012964] IFO 12964Sporolactobacillus inulinus [NRIC1133] NRIC 1133Candida rugosa [IF00750] IFO 0750Pichia burtonii [IF01986] IFO 1986Ashbya gossypii [IF01355] IFO 1355[Endomyces decipiens IF00102]Esherichia coli [IF03544] IFO 3544Serratia marcescens [IF03046] IFO 3046Pseudomonas aureofaciens [IF03522] IFO 3522[Bacillus subtilis IF03007][Brevibacterium ammoniagenes [IAM1641]Flavobacterium suaveolens [IF03752] IFO 3572 andParacoccus denitrificans [IF012442] IFO 12442______________________________________

and recovering the optically active (S)-2-hydroxy acid derivative of the formula (II) so produced.

19. The process of claim 16, wherein said microorganism has been collected from the culture and resuspended in an aqueous medium prior to treating the said 2-oxo acid.

20. The process of claim 18, wherein said microorganism has been collected from the culture and the cells ground, treated with acetone, or lyophilized prior to treating the said 2-oxo acid.

21. A process for the production of an optically active 2 -hydroxy acid derivative represented by the formula (II): ##STR17## wherein X.sub.1 and X.sub.2 represent each a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group or an alkyl group, R represents an alkyl or a phenyl group, and n is an integer ranging from 0 to 3,

which comprises treating a 2-oxo acid derivative represented by the formula (I): ##STR18## wherein X.sub.1, X.sub.2, R and n are as previously defined, with a microorganism capable of asymmetrically reducing said 2-oxo acid derivative of the formula (I) into an optically active (R)-form of said 2-hydroxy acid derivative of the formula (II), wherein said microorganism is selected from the group consisting of:

______________________________________Sporidiobolus pararoseus [AHU3447] AHU 3447Rhodosporidium toruloides [IF00559] IFO 0559[Saccharomyces rouxii IAM4011]Lactobacillus casei [IF012004] lFO 12004Leuconostoc mesenteroides [IF03349] IFO 3349 andsubsp. dextranicumStreptococcus equinus [NRIC1139] NRIC 1139and recovering the optically active (R)-2-hydroxy acidderivative of the formula (II) so produced.______________________________________

and recovering the optically active (R)-2-hydroxy acid derivative of the formula (II) so produced.

22. The process of claim 21, wherein said microorganism has been collected from the culture and resuspended in an aqueous medium prior to treating the said 2-oxo acid.

23. The process of claim 21, wherein said microorganism has been collected from the culture and the cells ground, treated with acetone, or lyophilized prior to treating the said 2-oxo acid.

24. A process for the production of an optically active 2-hydroxy acid derivative represented by the formula (II): ##STR19## wherein X.sub.1 and X.sub.2 represent each a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group or an alkyl group, R represents an alkyl or a phenyl group, and n is an integer ranging from 0 to 3,

which comprises treating a 2-oxo acid derivative represented by the formula (I): ##STR20## wherein X.sub.1, X.sub.2, R and n are as previously defined, with a microorganism capable of asymmetrically reducing said 2-oxo acid derivative of the formula (I) into an optically active (S)-form of said 2-hydroxy acid derivative of the formula (II), wherein said microorganism is selected from the group consisting of:

______________________________________Lactobacillus plantarum [IF03070] IFO 3070Ashbya gossypii [IF01355] IFO 1355[Endomyces decipiens IF00102]Serratia marcescens [IF03046] IFO 3046Esherichia coli [IF03544] IFO 3544Pseudomonas aureofaciens [IF03522] IFO 3522Leuconostoc mesenteroides [AHU1067] AHU 1067Streptococcus faecalis [IF012964] IFO 12964Sporolactobacillus inulinus [NRIC1133] NRIC 1133[Candida pseudotropicalis IAM4829]Candida rugosa [IF00750] IFO 0750Pichia burtonii [IF01986] IFO 1986Trigonopsis variabilis [IF00755] IFO 0755[Bacillus subtilis IF03007][Brevibacterium ammoniagenes IAM1641]Flavobacterium suaveolens [IF03752] IFO 3752 andParacoccus denitrificans [IF012442] IFO 12442______________________________________

and recovering the optically active (S)-2-hydroxy acid derivative of the formula (II) so produced.

25. The process of claim 24, wherein said microorganism has been collected from the culture and resuspended in an aqueous medium prior to treating the said 2-oxo acid.

26. The process of claim 24, wherein said microorganism has been collected from the culture and the cells ground, treated with acetone, or lyophilized prior to treating the said 2-oxo acid.

27. A process for the production of an optically active 2-hydroxy acid derivative represented by the formula (II): ##STR21## wherein X.sub.1 and X.sub.2 represent each a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group or an alkyl group, R represents an alkyl or a phenyl group, and n is an integer ranging from 0 to 3,

which comprises treating a 2-oxo acid derivative represented by the formula (I): ##STR22## wherein X.sub.1, X.sub.2, R and n are as previously defined, with a microorganism capable of asymmetrically reducing said 2-oxo acid derivative of the formula (I) into an optically active (R)-form of said 2-hydroxy acid derivative of the formula (II), wherein said microorganism has all of the identifying characteristics of a microorganism selected from the group consisting of:

______________________________________Lactobacillus casei IFO 12004;subsp. caseiLeuconostoc mesenteroides IFO 3349;subsp. dextranicumStreptococcus equinus NRIC 1139;Sporidiobolus pararoseus AHU 3447; andRhodosporidium toruloides IFO 0559;______________________________________

and recovering the optically active (R)-2-hydroxy acid derivative of the formula (II) so produced.

28. A process for the production of an optically active 2-hydroxy acid derivative represented by the formula (II): ##STR23## wherein X.sub.1 and X.sub.2 represent each a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group or an alkyl group, R represents an alkyl or a phenyl group, and n is an integer ranging from 0 to 3,

which comprises treating a 2-oxo acid derivative represented by the formula (I): ##STR24## wherein X.sub.1, X.sub.2, R and n are as previously defined, with a microorganism capable of asymmetrically reducing said 2-oxo acid derivative of the formula (I) into an optically active (S)-form of said 2-hydroxy acid derivative of the formula (II), wherein said microorganism has all of the identifying characteristics of a microorganism selected from the group consisting of:

______________________________________Trigonopsis variabilis IFO 0755Lactobacillus plantarum IFO 3070;Streptococcus faecalis IFO 12964;Sporolactobacillus inulinus NRIC 1133;Candida rugosa IFO 0750;Pichia burtonii IFO 1986;Ashbya gossypii IFO 1355;Eserichia coli IFO 3544;Serratia marcescens IFO 3046;Pseudomonas aureofaciens IFO 3522;Leuconostoc mesenteroides AHU 1067Flavobacterium suaveolens IFO 3572; andParacoccus denitrificans IFO 12442;______________________________________

and recovering the optically active (S)-2-hydroxy acid derivative of the formula (II) so produced.