text: 2,3-Butanediol fermentation is anaerobic fermentation of glucose with 2,3-butanediol as one of the end products. The overall stoichiometry of the reaction is
  :2 pyruvate + NADH --> 2CO + 2,3-butanediol.
  Butanediol fermentation is typical for the facultative anaerobes Klebsiella and Enterobacter and is tested for using the Voges–Proskauer (VP) test. There are other alternative strains that can be used, talked about in details in the Alternative Bacteria Strains section below.
  The metabolic function of 2,3-butanediol is not known, although some have speculated that it was an evolutionary advantage for these microorganisms to produce a neutral product thats less inhibitory than other partial oxidation products and doesnt reduce the pH as much as mixed acids.
  There are many important industrial applications that butanediol can be used for, including antifreeze, food additives, antiseptic, and pharmaceuticals. It also is produced naturally in various places of the environment.