Figure 5
From: Accelerated green process of tetramethylpyrazine production from glucose and diammonium phosphate
Relationship between the concentration of the precursor acetoin and the yield of 2,3,5,6-tetramethylpyrazine (TMP). Up: the control experiments were performed in pure water solutions of acetoin and diammonium phosphate (DAP) with the molar ratio of acetoin/ammonium = 1/3.0; down: the reactions took place in different kinds of acetoin fermentation broths (points A to E). A, the fermentation broth of S. marcescens CICC 10187 (containing 1.6 g L-1 of acetoin) supplemented with 3.6 g L-1 of DAP; B, P. polymyxa CICC 23617 (containing 12.7 g L-1 of acetoin) supplemented with 28.6 g L-1 of DAP; C, B. subtilis CICC 10211 (containing 30.1 g L-1 of acetoin) supplemented with 67.7 g L-1 of DAP; D, P. polymyxa CICC 23617 (containing 12.7 g L-1 of acetoin) supplemented with 42.6 g L-1 of acetoin and 124.4 g L-1 of DAP; E, S. marcescens CICC 10187 (containing 1.6 g L-1 of acetoin) supplemented with 73.6 g L-1 of acetoin and 169.2 g L-1 of DAP. All the experiments were performed in triplicates at 95°C for 3 h.