highly significantp < 0.01
The regression equation for colony sporulation was: Y ( ln ( sporulation ) ) = 22.64 + 0.7365 × X 1 + 0.0313 × X 2 − − 0.4789 × X 4 + 0.0448 × X 5 − 0.4468 × X 7 Regression analysis showed that the Plackett-Burman model ( Table IV ) was highly significant ( p < 0.01), indicating that the model could be used to analyze significant factors of B. majiangensis MJ1015 sporulation.