Table 2 Independent variables and their coded levels chosen for BBD

From: Levan from Leuconostoc citreum BD1707: production optimization and changes in molecular weight distribution during cultivation

Variable code Variable Level
−1 0 + 1
A Cultivation time (h) 72 96 120
B Cultivation temperature (°C) 20 25 30
C Initial pH 5.5 6.5 7.5
D Sucrose concentration (g/L) 100 150 200