Exopolysaccharides from lactic acid bacteria: Technological bottlenecks and practical solutions

Microbial exopolysaccharides are added to or occur in a wide variety of foo d products, where they serve as viscosifying or gelling agents. Exogolysacc harides with different composition, size and structure are synthesized by s everal strains of lactic acid bacteria. Structural analyses combined with r heological studies reveal that there is considerable variation among the di fferent exopolysaccharides; some of them exhibit remarkable thickening and shear-thinning properties and display high intrinsic viscosities. Hence, se veral slime-producing lactic acid bacterium strains and their biopolymers h ave interesting functional and technological properties, which may be explo ited towards different products. However, the production of exopolysacchari des from lactic acid bacteria is low and often unstable, and their downstre am processing is difficult. Strain improvement, enhanced productivities and advanced modification and production processes (both enzyme and fermentati on technology) may contribute to their economic soundness.