Production of acetoin by Bacillus subtilis TH-49

Acetoin (3-hydroxy-2-butanone) is an important flavor compound, widely existing in dairy products and some fruits. An study has been performed on acetoin production Bacillus subtilis TH-49. The mutant was obtained by treating B. subtilis NT-50-44 with compound mutation and subjecting it to a shake flask fermentation selection procedure. It was proved that the main metabolite produced by mutant strain TH-49 was acetoin and there were almost no 2,3-butanediol and 2,3-butanedione by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) analysis. The acetoin production rate reached the highest value of 56.9 g/l in 100-1 fermenter fermentations from glucose.