1.1.1.B20 (2R,3R)-butane-2,3-diol + NAD+ - Bacillus thuringiensis serovar kurstaki (3R)-acetoin + NADH + H+ - r 436208 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Klebsiella pneumoniae (3R)-acetoin + NADH + H+ - r 440031 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Serratia marcescens (3R)-acetoin + NADH + H+ - r 440031 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Serratia sp. (3R)-acetoin + NADH + H+ - r 440031 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Paenibacillus brasilensis (3R)-acetoin + NADH + H+ - ? 440031 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Bacillus subtilis (3R)-acetoin + NADH + H+ - r 440031 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Bacillus thuringiensis serovar kurstaki (3R)-acetoin + NADH + H+ - ? 440031 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Corynebacterium glutamicum (3R)-acetoin + NADH + H+ - r 440031 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Klebsiella aerogenes (3R)-acetoin + NADH + H+ - r 440031 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Serratia sp. T241 (3R)-acetoin + NADH + H+ - ? 440031 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ preferred substrate Klebsiella pneumoniae (3R)-acetoin + NADH + H+ - r 440031 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ meso-butane-2,3-diol Pseudomonas aeruginosa (3R)-acetoin + NADH + H+ - ? 440031 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ slightly preferred substrate Bacillus thuringiensis serovar kurstaki (3R)-acetoin + NADH + H+ - ? 440031 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ stereoselective interconversion Pseudomonas aeruginosa (3R)-acetoin + NADH + H+ - ? 440031 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Corynebacterium glutamicum LMG 3730 (3R)-acetoin + NADH + H+ - r 440031 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Corynebacterium glutamicum BCRC 11384 (3R)-acetoin + NADH + H+ - r 440031 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Corynebacterium glutamicum ATCC 13032 (3R)-acetoin + NADH + H+ - r 440031 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Serratia marcescens CECT 977 (3R)-acetoin + NADH + H+ - r 440031 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Serratia marcescens DSMZ 14187 (3R)-acetoin + NADH + H+ - r 440031 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Corynebacterium glutamicum JCM 1318 (3R)-acetoin + NADH + H+ - r 440031 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Paenibacillus brasilensis PB24 (3R)-acetoin + NADH + H+ - ? 440031 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Klebsiella aerogenes KCTC 2190 (3R)-acetoin + NADH + H+ - r 440031 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Corynebacterium glutamicum NCIMB 10025 (3R)-acetoin + NADH + H+ - r 440031 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Bacillus subtilis BS168D (3R)-acetoin + NADH + H+ - r 440031 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Serratia marcescens 9C (3R)-acetoin + NADH + H+ - r 440031 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Corynebacterium glutamicum DSM 20300 (3R)-acetoin + NADH + H+ - r 440031 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Klebsiella pneumoniae acetoin + NADH + H+ - r 440032 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Bacillus licheniformis acetoin + NADH + H+ - r 440032 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Bacillus licheniformis WX-02 acetoin + NADH + H+ - r 440032 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Klebsiella pneumoniae CICC10011 acetoin + NADH + H+ - r 440032 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Parageobacillus thermoglucosidasius (3S)-acetoin + NADH + H+ - r 458385 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Pyrococcus furiosus (3S)-acetoin + NADH + H+ - r 458385 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Corynebacterium glutamicum (3S)-acetoin + NADH + H+ - r 458385 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Corynebacterium glutamicum LMG 3730 (3S)-acetoin + NADH + H+ - r 458385 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Corynebacterium glutamicum BCRC 11384 (3S)-acetoin + NADH + H+ - r 458385 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Pyrococcus furiosus ATCC 43587 (3S)-acetoin + NADH + H+ - r 458385 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Corynebacterium glutamicum ATCC 13032 (3S)-acetoin + NADH + H+ - r 458385 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Pyrococcus furiosus Vc1 (3S)-acetoin + NADH + H+ - r 458385 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Corynebacterium glutamicum JCM 1318 (3S)-acetoin + NADH + H+ - r 458385 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Pyrococcus furiosus JCM 8422 (3S)-acetoin + NADH + H+ - r 458385 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Corynebacterium glutamicum NCIMB 10025 (3S)-acetoin + NADH + H+ - r 458385 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Corynebacterium glutamicum DSM 20300 (3S)-acetoin + NADH + H+ - r 458385 1.1.1.B20 (2R,3S)-butane-2,3-diol + NAD+ - Parageobacillus thermoglucosidasius DSM 2542 (3S)-acetoin + NADH + H+ - r 458385 1.1.1.B20 (2S,3S)-2,3-butanediol + NAD+ (2S,3S)-2,3-butanediol is a poor substrate Corynebacterium glutamicum (3S)-acetoin + NADH - ? 413701 1.1.1.B20 (2S,3S)-2,3-butanediol + NAD+ low activity Serratia marcescens (3S)-acetoin + NADH + H+ - r 413702 1.1.1.B20 (2S,3S)-2,3-butanediol + NAD+ low activity Serratia marcescens H30 (3S)-acetoin + NADH + H+ - r 413702 1.1.1.B20 (2S,3S)-butane-2,3-diol + NAD+ - Klebsiella pneumoniae (S)-acetoin + NADH + H+ - r 421734 1.1.1.B20 (2S,3S)-butane-2,3-diol + NAD+ - Serratia marcescens (S)-acetoin + NADH + H+ - r 421734 1.1.1.B20 (2S,3S)-butane-2,3-diol + NAD+ - Serratia marcescens 9C (S)-acetoin + NADH + H+ - r 421734 1.1.1.B20 (3R)-acetoin + NADH + H+ - Escherichia coli meso-2,3-butanediol + NAD+ - r 421736 1.1.1.B20 (3R)-acetoin + NADH + H+ - Saccharomyces cerevisiae meso-2,3-butanediol + NAD+ - r 421736 1.1.1.B20 (3R)-acetoin + NADH + H+ - Klebsiella pneumoniae meso-2,3-butanediol + NAD+ - r 421736 1.1.1.B20 (3R)-acetoin + NADH + H+ - Serratia marcescens meso-2,3-butanediol + NAD+ - r 421736 1.1.1.B20 (3R)-acetoin + NADH + H+ - Bacillus licheniformis meso-2,3-butanediol + NAD+ - r 421736 1.1.1.B20 (3R)-acetoin + NADH + H+ low activity in vivo Escherichia coli meso-2,3-butanediol + NAD+ - r 421736 1.1.1.B20 (3R)-acetoin + NADH + H+ - Serratia marcescens H30 meso-2,3-butanediol + NAD+ - r 421736 1.1.1.B20 (3R)-acetoin + NADH + H+ - Klebsiella pneumoniae XJ-Li meso-2,3-butanediol + NAD+ - r 421736 1.1.1.B20 (3R)-acetoin + NADH + H+ - Bacillus licheniformis 10-1-A meso-2,3-butanediol + NAD+ - r 421736 1.1.1.B20 (3R)-acetoin + NADH + H+ - Bacillus licheniformis (2R,3S)-butane-2,3-diol + NAD+ - r 458390 1.1.1.B20 (3R)-acetoin + NADH + H+ - Serratia marcescens (2R,3S)-butane-2,3-diol + NAD+ - r 458390 1.1.1.B20 (3R)-acetoin + NADH + H+ - Bacillus licheniformis MW3 (2R,3S)-butane-2,3-diol + NAD+ - r 458390 1.1.1.B20 (3R)-acetoin + NADH + H+ - Serratia marcescens CECT 977 (2R,3S)-butane-2,3-diol + NAD+ - r 458390 1.1.1.B20 (3S)-acetoin + NADH + H+ at pH 9.0 Serratia marcescens (2S,3S)-2,3-butanediol + NAD+ - r 422187 1.1.1.B20 (3S)-acetoin + NADH + H+ at pH 9.0 Serratia marcescens H30 (2S,3S)-2,3-butanediol + NAD+ - r 422187 1.1.1.B20 (R)-acetoin + NADH + H+ - Bacillus subtilis meso-2,3-butanediol + NAD+ - r 440044 1.1.1.B20 (R)-acetoin + NADH + H+ - Corynebacterium glutamicum meso-2,3-butanediol + NAD+ - r 440044 1.1.1.B20 (R)-acetoin + NADH + H+ - Klebsiella aerogenes meso-2,3-butanediol + NAD+ - r 440044 1.1.1.B20 (R)-acetoin + NADH + H+ preferred reaction direction Klebsiella aerogenes meso-2,3-butanediol + NAD+ - r 440044 1.1.1.B20 (R)-acetoin + NADH + H+ - Klebsiella aerogenes KCTC 2190 meso-2,3-butanediol + NAD+ - r 440044 1.1.1.B20 (R)-acetoin + NADH + H+ preferred reaction direction Klebsiella aerogenes KCTC 2190 meso-2,3-butanediol + NAD+ - r 440044 1.1.1.B20 (R)-acetoin + NADPH + H+ very low activity Klebsiella aerogenes meso-2,3-butanediol + NADP+ - r 440448 1.1.1.B20 (R)-acetoin + NADPH + H+ very low activity Klebsiella aerogenes KCTC 2190 meso-2,3-butanediol + NADP+ - r 440448 1.1.1.B20 (R,R)-butane-2,3-diol + NAD+ - Pseudomonas aeruginosa (R)-acetoin + NADH + H+ - r 394598 1.1.1.B20 (R,R)-butane-2,3-diol + NAD+ stereoselective interconversion Pseudomonas aeruginosa (3R)-acetoin + NADH + H+ - r 458789 1.1.1.B20 (S)-acetoin + NADH + H+ - Corynebacterium glutamicum meso-2,3-butanediol + NAD+ - r 440459 1.1.1.B20 1,2-cyclohexanedione + NADH + H+ - Serratia marcescens (S,S)-1,2-cyclohexanediol + NAD+ - ? 458801 1.1.1.B20 1,2-cyclohexanedione + NADH + H+ - Serratia marcescens CECT 977 (S,S)-1,2-cyclohexanediol + NAD+ - ? 458801 1.1.1.B20 1,2-pentanediol + NADH + H+ low activity Serratia marcescens ? - ? 422245 1.1.1.B20 1,2-pentanediol + NADH + H+ low activity Serratia marcescens H30 ? - ? 422245 1.1.1.B20 1,2-propandiol + NADH + H+ low activity Serratia marcescens ? - ? 422247 1.1.1.B20 1-hydroxy-2-butanone + NADH + H+ - Pseudomonas aeruginosa ? + NAD+ - ? 458836 1.1.1.B20 1-phenyl-1,2-propanedione + NADH + H+ - Serratia marcescens (S)-2-hydroxy-1-phenylpropan-1-one + NAD+ - ? 458850 1.1.1.B20 1-phenyl-1,2-propanedione + NADH + H+ - Serratia marcescens CECT 977 (S)-2-hydroxy-1-phenylpropan-1-one + NAD+ - ? 458850 1.1.1.B20 2 (R,S)-acetoin + 2 NADPH + 2 H+ - Saccharomyces cerevisiae (2S,3S)-2,3-butanediol + meso-2,3-butanediol + NADP+ Ara1p is selective toward the acetoin carbonyl group, leading to an S-alcohol r 413864 1.1.1.B20 2 acetoin + 2 NADH + 2 H+ racemic mixture of (3S/3R)-acetoin Corynebacterium glutamicum (2S,3S)-2,3-butanediol + meso-2,3-butanediol + 2 NAD+ - r 440534 1.1.1.B20 2,3-heptanedione + NADH + H+ - Serratia marcescens 3-hydroxy-2-heptanone + NAD+ - ? 458913 1.1.1.B20 2,3-hexanedione + NADH + H+ - Serratia marcescens (S)-3-hydroxy-2-hexanone + NAD+ - ? 458914 1.1.1.B20 2,3-pentandione + NADH + H+ - Pseudomonas aeruginosa ? + NAD+ - ? 458915 1.1.1.B20 2,3-pentanedione + NADH + H+ - Serratia marcescens (3S)-3-hydroxy-2-pentanone + NAD+ - ? 458916 1.1.1.B20 3,4-hexanedione + NADH + H+ - Serratia marcescens (3S,4S)-3,4-hexanediol + NAD+ - ? 459012 1.1.1.B20 4-methyl-2-pentanone + NADH + H+ low activity Klebsiella pneumoniae 4-methyl-2-pentanol + NAD+ - r 422608 1.1.1.B20 4-methyl-2-pentanone + NADH + H+ low activity Klebsiella pneumoniae XJ-Li 4-methyl-2-pentanol + NAD+ - r 422608 1.1.1.B20 acetoin + NADH + H+ - Klebsiella pneumoniae (2R,3S)-butane-2,3-diol + NAD+ - r 440136 1.1.1.B20 acetoin + NADH + H+ - Bacillus licheniformis (2R,3S)-butane-2,3-diol + NAD+ - r 440136 1.1.1.B20 acetoin + NADH + H+ - Bacillus licheniformis WX-02 (2R,3S)-butane-2,3-diol + NAD+ - r 440136 1.1.1.B20 acetoin + NADH + H+ - Klebsiella pneumoniae CICC10011 (2R,3S)-butane-2,3-diol + NAD+ - r 440136 1.1.1.B20 acetoin + NADH + H+ racemic mixture of (3S/3R)-acetoin Bacillus licheniformis meso-2,3-butanediol + NAD+ - r 440137 1.1.1.B20 acetoin + NADH + H+ racemic mixture of (3S/3R)-acetoin Bacillus licheniformis 10-1-A meso-2,3-butanediol + NAD+ - r 440137 1.1.1.B20 butane-1,2-diol + NAD+ - Pseudomonas aeruginosa ? + NADH + H+ - ? 459500 1.1.1.B20 diacetyl + 2 NADH + 2 H+ - Pseudomonas aeruginosa (2R,3R)-butane-2,3-diol + 2 NAD+ - r 459616 1.1.1.B20 diacetyl + NADH + H+ - Serratia marcescens (3S)-acetoin + NAD+ - ? 423306 1.1.1.B20 diacetyl + NADH + H+ - Pseudomonas aeruginosa (3R)-acetoin + NAD+ - r 459617 1.1.1.B20 glycerol + NADH + H+ low activity Serratia marcescens ? - ? 423633 1.1.1.B20 L-acetoin + NADH - Klebsiella pneumoniae L-2,3-butanediol + NAD+ - ? 165096 1.1.1.B20 meso-2,3-butanediol + NAD+ - Corynebacterium glutamicum acetoin + NADH - ? 414842 1.1.1.B20 meso-2,3-butanediol + NAD+ - Klebsiella pneumoniae acetoin + NADH + H+ - ? 414843 1.1.1.B20 meso-2,3-butanediol + NAD+ - Serratia marcescens (3R)-acetoin + NADH + H+ - r 423830 1.1.1.B20 meso-2,3-butanediol + NAD+ - Bacillus subtilis (R)-acetoin + NADH + H+ - r 440319 1.1.1.B20 meso-2,3-butanediol + NAD+ - Klebsiella aerogenes (R)-acetoin + NADH + H+ - r 440319 1.1.1.B20 meso-2,3-butanediol + NAD+ the (S)-specific ADH-9 produces (R)-acetoin by an oxidative route starting from meso-2,3-butanediol uncultured bacterium (R)-acetoin + NADH + H+ - r 440319 1.1.1.B20 meso-2,3-butanediol + NAD+ enantioselective enzymatic synthesis of the alpha-hydroxy ketone(R)-acetoin from meso-2,3-butanediol uncultured bacterium (R)-acetoin + NADH + H+ - r 440319 1.1.1.B20 meso-2,3-butanediol + NAD+ - Klebsiella aerogenes KCTC 2190 (R)-acetoin + NADH + H+ - r 440319 1.1.1.B20 meso-2,3-butanediol + NADP+ very low activity Klebsiella aerogenes (R)-acetoin + NADPH + H+ - r 441605 1.1.1.B20 additional information (2R,3R)-2,3-butanediol is no substrate for the enzyme Serratia marcescens ? - ? 89 1.1.1.B20 additional information the enzyme is highly stereospecific, and shows no significant activities towards 2R,3R-2,3-butanediol, 1,4-butanediol, and 2S,3S-2,3-butanediol Klebsiella pneumoniae ? - ? 89 1.1.1.B20 additional information stereoisomeric composition analysis of 2,3-butanediol produced by strain 10-1-A using gas chromatography. Strain 10-1-A produces a mixture of (2R,3R)-2,3-butanediol and meso-2,3-butanediol with a ratio of nearly 1:1. As (3R)-acetoin is the major source of (2R,3R)-2,3-butanediol and meso-2,3-butanediol, a meso-butanediol dehydrogenase and a (2R,3R)-2,3-butanediol dehydrogenase are co-present in strain 10-1-A Bacillus licheniformis ? - ? 89 1.1.1.B20 additional information meso-2,3-butanediol dehydrogenase (BDH) catalyzes the redox reaction between (R)-acetoin and meso-2,3-butanediol Bacillus subtilis ? - ? 89 1.1.1.B20 additional information NMR identification and quantification of reaction products. Meso-2,3-butanediol is the major form (over 95% of the 2,3-butanediol pool, depending on oxygen availability) produced in fermentations using a strain that overexpresses ALS/ALDC of Lactobacillus lactis and BDH of Corynebacterium glutamicum, i.e., strain DELTAaceEDELTApqoDELTAldhA(pEKEx2als,aldB,butACg) Corynebacterium glutamicum ? - ? 89 1.1.1.B20 additional information reaction component identification and quantification by GC-MS. No or very poor activity with isopropanol 2-methyl-1-butanol, 2-methyl-2-butanol, 2,5-hexanediol, 1,4-butanediol uncultured bacterium ? - ? 89 1.1.1.B20 additional information the enzyme is also active with diacetyl and NADH Klebsiella aerogenes ? - ? 89 1.1.1.B20 additional information most of the Bacillus strains produce 2,3-butanediol but not acetoin as their major product Bacillus licheniformis ? - - 89 1.1.1.B20 additional information 2,3-butanediol dehydrogenase (BudC) catalyses the selective asymmetric reductions of prochiral alpha-diketones to the corresponding alpha-hydroxy ketones and diols. BudC is highly active towards structurally diverse diketones in combination with nicotinamide cofactor regeneration systems. Aliphatic diketones, cyclic diketones, and alkyl phenyl diketones are well accepted, whereas their derivatives possessing two bulky groups are not converted. In the reverse reaction vicinal diols are preferred over other substrates with hydroxy/keto groups in non-vicinal positions. Substrate specificity and stereoselectivity, overview. In the reductive reaction diacetyl is the preferred substrate of BudC over acetoin, while only meso-2,3-butanediol oxidation is catalysed by the enzyme under the conditions assessed. No activity with (2S,3S)-butane-2,3-diol and (2R,3R)-butane-2,3-diol. BudC is S-selective for the reduction of diacetyl yielding (S,S)-2,3-butanediol ((S,S)-2,3-BDO), rac-acetoin is reduced to both meso-2,3-BDO and (S,S)-2,3-BDO. Here (R)-acetoin is the preferred substrate and 15% (S)-acetoin remains unconverted after 24 h. Thus, BudC shows a stereo-preference consistent with meso-2,3-butanediol dehydrogenases with respect to acetoin. No activity with R-benzoin, rac-benzoin, benzil, acetone, 2,4-pentanediol, 1,3-butanediol, ethanol, and 2-propanol Serratia marcescens ? - - 89 1.1.1.B20 additional information enzyme BtBDH is active with meso-2,3-butanediol and (2R,3R)-2,3-butanediol, whereas no activity is observed with (2S,3S)-2,3-butanediol. BtBDH shows similar oxidative activity toward meso-2,3-butanediol and (2R,3R)-2,3-butanediol, and it exhibits a 3fold higher reduction activity toward acetoin compared to diacetyl Bacillus thuringiensis serovar kurstaki ? - - 89 1.1.1.B20 additional information meso-2,3-BDH from Serratia sp. T241 exhibits higher catalytic efficiency compared with the meso-2,3-BDHs from Klebsiella pneumoniae strain XJ-Li and Serratia marcescens strain H30. No activity is detected for (2R,3R)-2,3-BD as substrate by meso-2,3-BDH, but meso-2,3-BDH from Serratia sp. T241 can efficiently convert (2S,3S)-2,3-BD and meso-2,3-BD into (3S)-acetoin and (3R)-acetoin, respectively, cf. EC 1.1.1.76 Serratia sp. T241 ? - - 89 1.1.1.B20 additional information production of S,S- and/or R,R- and meso-2,3-BDO by Paenibacillus brasilensis strain PB24 grown in the modified YEPD medium, pH 6.3, 32°C, up to 72 h Paenibacillus brasilensis ? - - 89 1.1.1.B20 additional information substrate promiscuity of the SmBdh enzyme, SmBdh has been reported to be able to reduce both (3R)- and (3S)-acetoin to 2,3-BDO, although (3R)-acetoin is more readily converted than (3S)-acetoin. On the other hand, SmBdh is able to oxidize meso-2,3-BDO and (2S,3S)-BDO, while oxidation of (2R,3R)-BDO is not detectable. Moreover, its activity towards (2S,3S)-BDO is only 11% of that towards meso-2,3-BDO. The enzyme is classified as an S-acting Bdh based on production of meso-2,3-BDO and (2S,3S)-BDO from a racemic mixture of acetoin Serratia marcescens ? - - 89 1.1.1.B20 additional information the (2R,3R)-2,3-butanediol dehydrogenase is active with (R,R)-butane-2,3-diol, but also with meso-butane-2,3-diol, but not with with (2S,3S)-2,3-butane-2,3-diol. No activity with 2-butanol, 1,3-butanediol, 1,2-pentanediol, 1,3-propanediol, and glycerol in the oxidation reaction. And no activity with 2,4-pentanedione, butanone, 2,5-hexanedione, n-butanal and 1,3-dihydroxypropanone in the reduction reaction. Substrate specificity, overview. (2R,3R)-2,3-BDH reduces diacetyl into (3R)-acetoin and (2R,3R)-2,3-BD, while racemic acetoin is reduced into (2R,3R)-2,3-BD and meso-2,3-BD Pseudomonas aeruginosa ? - - 89 1.1.1.B20 additional information the meso-2,3-butanediol dehydrogenase from Klebsiella pneumoniae is active with meso-2,3-butanediol, but also with (2S,3S)-butane-2,3-diol (EC 1.1.1.76) converting them to (3R)-acetoin and (3S)-acetoin, respectively. Additionally the enzyme also has diacetyl reductase [(S)-acetoin forming] activity (EC 1.1.1.304) Klebsiella pneumoniae ? - - 89 1.1.1.B20 additional information most of the Bacillus strains produce 2,3-butanediol but not acetoin as their major product Bacillus licheniformis MW3 ? - - 89 1.1.1.B20 additional information (2R,3R)-2,3-butanediol is no substrate for the enzyme Serratia marcescens H30 ? - ? 89 1.1.1.B20 additional information 2,3-butanediol dehydrogenase (BudC) catalyses the selective asymmetric reductions of prochiral alpha-diketones to the corresponding alpha-hydroxy ketones and diols. BudC is highly active towards structurally diverse diketones in combination with nicotinamide cofactor regeneration systems. Aliphatic diketones, cyclic diketones, and alkyl phenyl diketones are well accepted, whereas their derivatives possessing two bulky groups are not converted. In the reverse reaction vicinal diols are preferred over other substrates with hydroxy/keto groups in non-vicinal positions. Substrate specificity and stereoselectivity, overview. In the reductive reaction diacetyl is the preferred substrate of BudC over acetoin, while only meso-2,3-butanediol oxidation is catalysed by the enzyme under the conditions assessed. No activity with (2S,3S)-butane-2,3-diol and (2R,3R)-butane-2,3-diol. BudC is S-selective for the reduction of diacetyl yielding (S,S)-2,3-butanediol ((S,S)-2,3-BDO), rac-acetoin is reduced to both meso-2,3-BDO and (S,S)-2,3-BDO. Here (R)-acetoin is the preferred substrate and 15% (S)-acetoin remains unconverted after 24 h. Thus, BudC shows a stereo-preference consistent with meso-2,3-butanediol dehydrogenases with respect to acetoin. No activity with R-benzoin, rac-benzoin, benzil, acetone, 2,4-pentanediol, 1,3-butanediol, ethanol, and 2-propanol Serratia marcescens CECT 977 ? - - 89 1.1.1.B20 additional information the enzyme is highly stereospecific, and shows no significant activities towards 2R,3R-2,3-butanediol, 1,4-butanediol, and 2S,3S-2,3-butanediol Klebsiella pneumoniae XJ-Li ? - ? 89 1.1.1.B20 additional information production of S,S- and/or R,R- and meso-2,3-BDO by Paenibacillus brasilensis strain PB24 grown in the modified YEPD medium, pH 6.3, 32°C, up to 72 h Paenibacillus brasilensis PB24 ? - - 89 1.1.1.B20 additional information stereoisomeric composition analysis of 2,3-butanediol produced by strain 10-1-A using gas chromatography. Strain 10-1-A produces a mixture of (2R,3R)-2,3-butanediol and meso-2,3-butanediol with a ratio of nearly 1:1. As (3R)-acetoin is the major source of (2R,3R)-2,3-butanediol and meso-2,3-butanediol, a meso-butanediol dehydrogenase and a (2R,3R)-2,3-butanediol dehydrogenase are co-present in strain 10-1-A Bacillus licheniformis 10-1-A ? - ? 89 1.1.1.B20 additional information the enzyme is also active with diacetyl and NADH Klebsiella aerogenes KCTC 2190 ? - ? 89 1.1.1.B20 additional information substrate promiscuity of the SmBdh enzyme, SmBdh has been reported to be able to reduce both (3R)- and (3S)-acetoin to 2,3-BDO, although (3R)-acetoin is more readily converted than (3S)-acetoin. On the other hand, SmBdh is able to oxidize meso-2,3-BDO and (2S,3S)-BDO, while oxidation of (2R,3R)-BDO is not detectable. Moreover, its activity towards (2S,3S)-BDO is only 11% of that towards meso-2,3-BDO. The enzyme is classified as an S-acting Bdh based on production of meso-2,3-BDO and (2S,3S)-BDO from a racemic mixture of acetoin Serratia marcescens 9C ? - - 89 1.1.1.B20 additional information enzyme BtBDH is active with meso-2,3-butanediol and (2R,3R)-2,3-butanediol, whereas no activity is observed with (2S,3S)-2,3-butanediol. BtBDH shows similar oxidative activity toward meso-2,3-butanediol and (2R,3R)-2,3-butanediol, and it exhibits a 3fold higher reduction activity toward acetoin compared to diacetyl Bacillus thuringiensis serovar kurstaki ACCC 10066 ? - - 89 1.1.1.B20 propane-1,2-diol + NAD+ - Pseudomonas aeruginosa ? + NADH + H+ - ? 459875 1.1.1.B20 rac acetoin + NADH + H+ - Pseudomonas aeruginosa (2R,3R)-butane-2,3-diol + NAD+ - ? 459884 1.1.1.B20 rac acetoin + NADH + H+ - Pseudomonas aeruginosa (2R,3S)-butane-2,3-diol + NAD+ - ? 459885