Microbial Modification of Extracellular Polysaccharides

Some trials to alter the structure of extracellular polysaccharides by means of biotransformation and microbial modification have been reported. Seaweed alginate was acetylated by intact and resting cells of Pseudomonas syringae ATCC 19304. Glucose analogs such as 3-O-methyl-D-glucose used as sole carbon sources was directly incorporated into curdlan by agrobacterium sp. ATCC 31749. The 2-amino-2-deoxy-D-glucose (glucosamine)and 2-acetamido-2-deoxy-D-glucose (N-acetylglucosamine) were incorporated into microbial cellulose by Acetobacter xylinum ATCC 10245. The changed monomeric composition in pullulan by Aureobasidium pullulans ATCC 42023 as well as zooglan by Zoogoea ramigera ATCC 25935 was another effect of glucose analogs used a carbon source. There was no effect of glucose analogs found in polysacharide-7 (PS-7) produced by Beijerinckia indica. ATCC 21423.