Background: Integrated statistical experimental designs were applied to
optimize the medium constituents for the production of a dimethyl
phthalate (DMP)-degrading strain Bacillus sp. QD14 in shake-flask
cultures. A Plackett\u2013Burman design (PBD) was applied to screen
for significant factors, followed by the Steepest Ascent Method (SAM)
to find the nearest region of maximum response. A Box\u2013Behnken
design (BBD) of the Response Surface Methodology (RSM) was conducted to
optimize the final levels of the medium components. Results: After the
regression equation and response surface contour plots were analyzed,
the concentrations of glucose, corn meal and NaCl were found to
significantly influence the biomass of DMP-degrading bacteria. A
combination of 22.88 g/L of glucose, 11.74 g/L of corn meal, and 10.34
g/L of NaCl was optimum for maximum biomass production of Bacillus sp.
QD14. A 57.11% enhancement of the biomass production was gained after
optimization in shake-flask cultivation. The biomass production of
Bacillus sp. QD14 reached 9.13 \ub1 0.29
7 108 CFU/mL, which was
an excellent match for the predicted value, and the mean value of the
match degree was as high as 99.30%. Conclusion: In this work, the key
factors affected by the fermentation of DMP-degrading strain Bacillus
sp. QD14 were optimized by PBD, SAM and BBD (RSM); the yield was
increased by 57,11% in the conditions in our study. We propose that the
conditions optimized in the study can be applied to the fermentation
for commercialization production