Research Article

Optimization of Fermentation Conditions and Media for Production of Glucose Isomerase from Bacillus megaterium Using Response Surface Methodology

Table 2

Experimental variables at different levels and their impacts on glucose isomerase production in Plackett–Burman experimental design matrix.

FactorsLevelsImpact levels
SymbolsVariablesLow (−1)High (+1)ImpactProb > F value

X1D-xylose concentration (%)0.51.50.019b0.014
X2K2HPO4 concentration (%)0.10.3−0.004a0.194
X3MgSO4 concentration (%)0.050.150.002a0.382
X4Yeast extract concentration (%)0.751.250.02b0.012
X5Peptone concentration (%)0.51.50.005a0.157
X6pH6.57.5−0.002a0.536
X7Bacterial inoculum size (%)15250.002a0.501
X8Cultivation temperature (oC)3539−0.002b0.011
X9Rotation rate (rpm)1001400.008a0.071

The letter “a” indicates no significant impact with 95% confidence level; the letter “b” indicates significant impact with 95% confidence level.