Updated BioCyc iOS App now
available in iTunes store
Updated BioCyc iOS App now
available in iTunes store
Updated BioCyc iOS App now
available in iTunes store
Updated BioCyc iOS App now
available in iTunes store
Updated BioCyc iOS App now
available in iTunes store

MetaCyc Pathway: (R)-acetoin biosynthesis I
Inferred from experiment

Enzyme View:

Pathway diagram: (R)-acetoin biosynthesis I

This view shows enzymes only for those organisms listed below, in the list of taxa known to possess the pathway. If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.

Synonyms: D-acetoin biosynthesis I

Superclasses: Generation of Precursor Metabolites and EnergyFermentationAcetoin Biosynthesis

Some taxa known to possess this pathway include : Aeromonas hydrophila, Bacillus subtilis, Brevibacillus brevis S1, Corynebacterium glutamicum, Enterobacter aerogenes, Klebsiella pneumoniae, Lactobacillus brevis, Lactobacillus casei, Lactobacillus helveticus, Lactobacillus plantarum, Lactococcus lactis, Lactococcus lactis lactis bv. diacetylactis, Leuconostoc lactis, Leuconostoc mesenteroides cremoris, Oenococcus oeni, Pediococcus pentosaceus, Raoultella terrigena, Saccharomyces cerevisiae, Serratia marcescens

Expected Taxonomic Range: Bacteria , Fungi

Many bacterial species can ferment pyruvate to acetoin and a 2,3-butanediol via (S)-2-acetolactate.

In lactic acid bacteria (LAB), pyruvate (which can be formed in large amounts from citrate) is converted into either lactate, by the enzymes L-lactate dehydrogenase or D-lactate dehydrogenase, or to (S)-2-acetolactate by the enzyme α-acetolactate synthase (α-ALS). The conversion of pyruvate to lactate requires NADH, so under conditions of low NADH, the majority of the pyruvate is converted to 2-acetolactate. The relative activities of α-ALS and α-ALD in specific strains determine the fluxes and concentrations of the different intermediates in these organisms.

2-acetolactate is an unstable intermediate. In the presence of oxygen it can undergo a spontaneous decarboxylation, producing diacetyl. Once diacetyl is formed, it can be converted to acetoin by the activity of the enzyme diacetyl reductase (also known as acetoin dehydrogenase).

Under anaerobic conditions 2-acetolactate is converted directly to acetoin by α-acetolactate decarboxylase (α-ALD) (see (R)-acetoin biosynthesis II).

(R)-acetoin is often converted to (R,R)-2,3-butanediol by the enzyme R-acetoin reductase (see (R,R)-butanediol biosynthesis).

There seems to be some confusion concerning the two enzyme activities acetoin reductase and diacetyl reductase. Initially, they were reported to be catalyzed by two different enzymes [Strecker54], and two different EC numbers were issued based on that observation (EC and EC However, later research indicated that at least in Enterobacter aerogenes both activities are catalyzed by the same enzyme, for which the name diacetyl(acetoin) reductase was suggested [Bryn71]. Subsequent work supported that finding [Larsen73, Carballo91, Aungpraphapornc99]. As a matter of fact, the enzyme appears to have a much wider substrate range than orignally believed, and it has been suggested to rename it L-glycol dehydrogenase [Carballo91].

This pathway includes multiple decarboxylation reactions, generating CO2. This CO2 is the source of the "eyes", or holes that certain cheeses, such as Swiss cheese, develop during maturation.

Superpathways: superpathway of (R,R)-butanediol biosynthesis

Variants: (R)-acetoin biosynthesis II, (S)-acetoin biosynthesis, acetoin biosynthesis III

Created 21-May-2008 by Caspi R, SRI International


Aungpraphapornc99: Aungpraphapornchai P, Griffin HG, Gasson MJ (1999). "Cloning, DNA sequence analysis, and deletion of a gene encoding diacetyl-acetoin reductase from Lactococcus lactis." DNA Seq 10(3);163-72. PMID: 10647818

Blomqvist93: Blomqvist K, Nikkola M, Lehtovaara P, Suihko ML, Airaksinen U, Straby KB, Knowles JK, Penttila ME (1993). "Characterization of the genes of the 2,3-butanediol operons from Klebsiella terrigena and Enterobacter aerogenes." J Bacteriol 175(5);1392-404. PMID: 8444801

Booth83: Booth IR, Kroll RG (1983). "Regulation of cytoplasmic pH (pH1) in bacteria and its relationship to metabolism." Biochem Soc Trans 11(1);70-2. PMID: 6298028

Bryn71: Bryn K, Hetland O, Stormer FC (1971). "The reduction of diacetyl and acetoin in Aerobacter aerogenes. Evidence for one enzyme catalyzing both reactions." Eur J Biochem 18(1);116-9. PMID: 5540507

Carballo91: Carballo J, Martin R, Bernardo A, Gonzalez J (1991). "Purification, characterization and some properties of diacetyl(acetoin) reductase from Enterobacter aerogenes." Eur J Biochem 198(2);327-32. PMID: 2040298

Gonzalez00: Gonzalez E, Fernandez MR, Larroy C, Sola L, Pericas MA, Pares X, Biosca JA (2000). "Characterization of a (2R,3R)-2,3-butanediol dehydrogenase as the Saccharomyces cerevisiae YAL060W gene product. Disruption and induction of the gene." J Biol Chem 275(46);35876-85. PMID: 10938079

Larsen73: Larsen SH, Johansen L, Stormer FC, Storesund HJ (1973). "Formation of 2,3-pentanediol from 2,3-pentanedione and acetylethylcarbinol by diacetyl(acetoin)reductase from Aerobacter aerogenes. A possible new pathway." FEBS Lett 31(1);39-41. PMID: 4350968

Magee87: Magee, R.J., Kosaric, N. (1987). "The microbial production of 2,3-butanediol." Adv. Appl. Microbiol. 32: 89-161.

Oppermann94: Oppermann FB, Steinbuchel A (1994). "Identification and molecular characterization of the aco genes encoding the Pelobacter carbinolicus acetoin dehydrogenase enzyme system." J Bacteriol 176(2);469-85. PMID: 8110297

Strecker54: Strecker, H.J., Harary, I. (1954). "Bacterial butylene glycol dehydrogenase and diacetyl reductase." J Biol Chem 211(1);263-70. PMID: 13211662

Syu01: Syu MJ (2001). "Biological production of 2,3-butanediol." Appl Microbiol Biotechnol 55(1);10-8. PMID: 11234948

Takusagawa01: Takusagawa Y, Otagiri M, Ui S, Ohtsuki T, Mimura A, Ohkuma M, Kudo T (2001). "Purification and characterization of L-2,3-butanediol dehydrogenase of Brevibacterium saccharolyticum C-1012 expressed in Escherichia coli." Biosci Biotechnol Biochem 65(8);1876-8. PMID: 11577733

Wardwell01: Wardwell SA, Yang YT, Chang HY, San KY, Rudolph FB, Bennett GN (2001). "Expression of the Klebsiella pneumoniae CG21 acetoin reductase gene in Clostridium acetobutylicum ATCC 824." J Ind Microbiol Biotechnol 27(4);220-7. PMID: 11687934

Other References Related to Enzymes, Genes, Subpathways, and Substrates of this Pathway

Aymes99: Aymes, F., Monnet, C., Corrieu, G. (1999). "Effect of α-acetolactate decarboxylase inactivation on α-acetolactate and diacetyl production by Lactococcus lactis subsp. lactisdiacetylactis." J. Biosci. Bioeng. 87:87-92. PMID: 16232430

Barak88: Barak Z, Calvo JM, Schloss JV (1988). "Acetolactate synthase isozyme III from Escherichia coli." Methods Enzymol 1988;166;455-8. PMID: 3071721

Bartowsky04: Bartowsky EJ, Henschke PA (2004). "The 'buttery' attribute of wine--diacetyl--desirability, spoilage and beyond." Int J Food Microbiol 96(3);235-52. PMID: 15454314

De78: De Felice M, Squires C, Levinthal M (1978). "A comparative study of the acetohydroxy acid synthase isoenzymes of Escherichia coli K-12." Biochim. Biophys. Acta 541;9-17.

deFelice78: de Felice M, Squires C, Levinthal M "A comparative study of the acetohydroxy acid synthase isoenzymes of Escherichia coli K-12." BBA 1978;541:9-17.

Diderichsen90: Diderichsen B, Wedsted U, Hedegaard L, Jensen BR, Sjoholm C (1990). "Cloning of aldB, which encodes alpha-acetolactate decarboxylase, an exoenzyme from Bacillus brevis." J Bacteriol 172(8);4315-21. PMID: 2198252

Ehsani09: Ehsani M, Fernandez MR, Biosca JA, Julien A, Dequin S (2009). "Engineering of 2,3-butanediol dehydrogenase to reduce acetoin formation by glycerol-overproducing, low-alcohol Saccharomyces cerevisiae." Appl Environ Microbiol 75(10);3196-205. PMID: 19329666

Ehsani09a: Ehsani M, Fernandez MR, Biosca JA, Dequin S (2009). "Reversal of coenzyme specificity of 2,3-butanediol dehydrogenase from Saccharomyces cerevisae and in vivo functional analysis." Biotechnol Bioeng 104(2);381-9. PMID: 19507198

Gollop82: Gollop N, Tavori H, Barak Z (1982). "Acetohydroxy acid synthase is a target for leucine containing peptide toxicity in Escherichia coli." J Bacteriol 149(1);387-90. PMID: 7033214

Gollop83: Gollop N, Chipman DM, Barak Z (1983). "Inhibition of acetohydroxy acid synthase by leucine." Biochim Biophys Acta 1983;748(1);34-9. PMID: 6351926

Gollop89: Gollop N, Damri B, Barak Z, Chipman DM (1989). "Kinetics and mechanism of acetohydroxy acid synthase isozyme III from Escherichia coli." Biochemistry 28(15);6310-7. PMID: 2675968

Grimminger79: Grimminger H, Umbarger HE (1979). "Acetohydroxy acid synthase I of Escherichia coli: purification and properties." J Bacteriol 1979;137(2);846-53. PMID: 370104

Heidlas90: Heidlas J, Tressl R (1990). "Purification and characterization of a (R)-2,3-butanediol dehydrogenase from Saccharomyces cerevisiae." Arch Microbiol 154(3);267-73. PMID: 2222122

Hill97: Hill CM, Pang SS, Duggleby RG (1997). "Purification of Escherichia coli acetohydroxyacid synthase isoenzyme II and reconstitution of active enzyme from its individual pure subunits." Biochem J 327 ( Pt 3);891-8. PMID: 9581571

LaRossa84: LaRossa RA, Schloss JV (1984). "The sulfonylurea herbicide sulfometuron methyl is an extremely potent and selective inhibitor of acetolactate synthase in Salmonella typhimurium." J Biol Chem 1984;259(14);8753-7. PMID: 6378902

Latendresse13: Latendresse M. (2013). "Computing Gibbs Free Energy of Compounds and Reactions in MetaCyc."

Lu14a: Lu J, Brigham CJ, Plassmeier JK, Sinskey AJ (2014). "Characterization and modification of enzymes in the 2-ketoisovalerate biosynthesis pathway of Ralstonia eutropha H16." Appl Microbiol Biotechnol. PMID: 25081555

Marugg94: Marugg JD, Goelling D, Stahl U, Ledeboer AM, Toonen MY, Verhue WM, Verrips CT (1994). "Identification and characterization of the alpha-acetolactate synthase gene from Lactococcus lactis subsp. lactis biovar diacetylactis." Appl Environ Microbiol 60(4);1390-4. PMID: 8017926

OSullivan01: O'Sullivan SM, Condon S, Cogan TM, Sheehan D (2001). "Purification and characterisation of acetolactate decarboxylase from Leuconostoc lactis NCW1." FEMS Microbiol Lett 194(2);245-9. PMID: 11164316

Pang04: Pang SS, Duggleby RG, Schowen RL, Guddat LW (2004). "The crystal structures of Klebsiella pneumoniae acetolactate synthase with enzyme-bound cofactor and with an unusual intermediate." J Biol Chem 279(3);2242-53. PMID: 14557277

Showing only 20 references. To show more, press the button "Show all references".

Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by Pathway Tools version 19.5 (software by SRI International) on Wed Feb 10, 2016, biocyc13.