Cold-Shock Stress Induces Formation of a Biopolymer Flocculant by Bacillus alvei NRC-14 under Static Incubation Conditions
Bacillus alvei NRC-14, a soil bacterial isolate, was found to exhibit multiple-adaptive response when exposed to abiotic stress factors. In the present study, chemical and flocculation properties of a viscous biopolymer flocculant produced by the strain under cold-shock stress are investigated. Addition of sucrose or starch at a 1% concentration increased the growth and viscosity. The biopolymer flocculant is a polysaccharide as indicated by the sugars content. Maximum values of viscosity and flocculating activity were obtained at a pH range from 5–9.