Differentiation between Bacillus amyloliquefaciens and Bacillus subtilis isolated from a South African sugarcane processing factory using ARDRA and rpoB gene sequencing.

A total of 104 exopolysaccharide (gum)-producing bacteria were isolated from the juice screen and juice tank in a sugarcane processing factory at times of low- and high dextran concentrations in the produced sugar. Dextran is an indicator of cane deterioration and sucrose loss after harvesting of the cane. The isolates were identified as Bacillus amyloliquefaciens (96 isolates) and Bacillus subtilis (eight isolates) based on restriction enzyme banding patterns of amplified 16S rRNA genes and rpoB gene sequence analysis. Exopolysaccharide production in sugarcane is normally associated with dextran produced by Leuconostoc mesenteroides. B. amyloliquefaciens, and to a lesser extent B. subtilis, could, however, also be responsible for exopolysaccharide (slime or gum) production in cane processing factories.