sentence: Under this condition , the concentration of acetylacetone in fermentation broth was 32.6 ± 1.0 mg / L. Furthermore , the production of acetylacetone was also performed in vitro in Tris buffer ( pH 7.5 ) containing purified Dke1 protein , methylglyoxal and ammonium acetate at 37 ° C , and 129.5 ± 8.9 mg / L acetylacetone was accumulated in 24 h. Compared with in vivo system , higher product titer was achieved with in vitro system , probably owing to a relatively simple pathway without side reactions [ 15 ] .