Use of Bacillus subtilis starter cultures during red sorghum malting

Bacillus subtilis was used to inhibit mould growth during red sorghum malting. Improved conditions for achieving good malt properties were studied and mathematical models are proposed for the induction and the repression phases of α- and β-amylase synthesis. The problems associated with the hydrolysis of β-glucans and the biocontrol steeping effect on β-glucanase activities are discussed. The effect of the biocontrol treatment and that of phytohormones produced by the bacterial strain used on the synthesis of specific red sorghum enzymes are elucidated. Gibberellic acid and abscisic acid diffusion and cross-talk as factors affecting the synthesis of red sorghum malt α- and β-amylase activities are also discussed. The production of 3-indole acetic acid (IAA) by B. subtilis S499 was also a focus in this study and the determination of the conditions for improving the production of indole-3-acetic acid are determined.