Comparative Assessment of Factors Involved in Acetoin Synthesis by Bacillus subtilis 168

Table 4

Comparison of acetoin yield, specific acetoin production, and maximum possible change in acetoin accumulation by variation of glucose, pyruvate, temperature, pH, aeration, and acetoin synthesis enzyme.

Physiological parameters	Acetoin yield (mole of acetoin produced/mole of glucose used)	% maximum possible change in acetoin accumulation
Glucose (g/L)
2.5	0.004	32.0
5	0.02
10	0.081
Temperature
25	0.020	30.1
37	0.101
42	0.024
pH
5.5	0.071	38.5
7.5	0.108
9.5	0.051
Aeration (rpm)
50	0.040	49.8
100	0.143
250	0.102
ALS and ALDC
168	0.107	80.3
BS7432	0.245

∗Percentage of the highest acetoin accumulation is calculated as {highest acetoin titre (g/L) − lowest acetoin titre (g/L)/highest acetoin titre (g/L)}∗100.