Research Article

Enhanced Cellulase Production from Bacillus subtilis by Optimizing Physical Parameters for Bioethanol Production

Table 3

Result of Student’s t-test for alkaline CMCase activity and the cell growth in the optimization study.

TermCMCase activity (U/mL)Cell growth (g/L)

Constant 28.927 0.000 57.032 0.000
pH ( ) 4.229 0.002 3.518 0.006
Temperature (°C) ( ) 8.712 0.000 4.355 0.001
Agitation (rpm) ( )−4.3410.001 8.136 0.000
( )−0.1920.852−8.5110.000
( )−7.9380.000−13.0260.000
( )−0.7280.483−5.2720.000
−1.8480.094−0.2070.840
0.387 0.707 0.259 0.801
−3.3320.008 2.482 0.032

t statistic is the coefficient divided by its standard error, is probability of incorrectly rejecting the null hypothesis when it is actually true.