Factors affecting decreasing viscosity of the culture medium during the stationary growth phase of exopolysaccharide-producing MTCC 25067.

MTCC 25067 produces a hetero-exopolysaccharide (HePS) when cultured which forms supramolecular networks in the culture medium, increasing the viscosity. In the present study, the viscosity of the bacterial culture reached its maximum at 48 hr of cultivation and then decreased during a stationary growth phase lasting for up to 144 hr. The monosaccharide composition did not change during the stationary growth phase, whereas degradation of HePS molecules was noticeable, leading to partial disintegration of their supramolecular networks.