title: The Bacillus subtilis ydjL (bdhA) gene encodes acetoin reductase/2,3-butanediol dehydrogenase.
abstract: Bacillus subtilis is capable of producing 2,3-butanediol from acetoin by fermentation, but to date, the gene encoding the enzyme responsible, acetoin reductase/2,3-butanediol dehydrogenase (AR/BDH), has remained unknown. A search of the B. subtilis genome database with the amino acid sequences of functional AR/BDHs from Saccharomyces cerevisiae and Bacillus cereus resulted in the identification of a highly similar protein encoded by the B. subtilis ydjL gene. A knockout strain carrying a ydjL::cat insertion mutation was constructed, which (i) abolished 2,3-butanediol production in early stationary phase, (ii) produced no detectable AR or BDH activity in vitro, and (iii) accumulated the precursor acetoin in early stationary phase. The ydjL::cat mutation also affected the kinetics of lactate but not acetate production during stationary-phase cultivation with glucose under oxygen limitation. A very small amount of 2,3-butanediol was detected in very-late-stationary-phase (96-hour) cultures of the ydjL::cat mutant, suggesting the existence of a second gene encoding a minor AR activity. From the data, it is proposed that the major AR/BDH-encoding gene ydjL be renamed bdhA.
authors.affiliation: Department of Microbiology and Cell Science, University of Florida, Kennedy Space Center, Florida 32899, USA. WLN@ufl.edu
authors.forename: Wayne L
authors.initials: WL
authors.lastname: Nicholson
mesh_terms: D019342:Acetic Acid / Q000378:metabolism; D000093:Acetoin / Q000378:metabolism*; D000429:Alcohol Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D001409:Bacillus cereus / Q000235:genetics; D001412:Bacillus subtilis / Q000201:enzymology* / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002072:Butylene Glycols / Q000378:metabolism*; D017353:Gene Deletion; D005947:Glucose / Q000378:metabolism; D019344:Lactic Acid / Q000378:metabolism; D016254:Mutagenesis, Insertional; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D002072:Butylene Glycols; D019344:Lactic Acid; C026978:2,3-butylene glycol; D000093:Acetoin; D010088:Oxidoreductases; D000429:Alcohol Oxidoreductases; C019801:butanediol dehydrogenase; D005947:Glucose; D019342:Acetic Acid; D010100:Oxygen