ABSTRACT
Polysaccharides derived from Gram-positive and Gram-negative bacteria are divided into two groups; capsular polysaccharides (CPS) and exopolysaccharides (EPS). CPS is permanently attached to the outer surface of the cells and EPS is secreted into the growth medium. These polysaccharides are either homopolysaccharides containing a single type of monosaccharide or heteropolysaccharides containing several types of monosaccharides. Many strain Acetic acid bacteria synthesize high amounts of exopolysaccharides. Some strains of Acetobacter and Komagataeibacter produce extracellular homopolysaccharides, such as cellulose or heteropolysaccharides like acetan. Cellulose is produced in two forms by Komagataeibacter species as cellulose I and cellulose II. B. E. Rangaswamy aimed to isolate cellulose-producing bacteria from rotten fruits and rotten vegetables and isolated thirty different cellulose producers from natural sources. Some bacterial strains also produce cellulose with the same chemical structure of linear ß-1, 4 glucan chains as plant-derived cellulose. Molecular weight of levan is highly dependent on the microorganism and the fermentation parameters used for its production.
