ABSTRACT
I. Introduction 176
II. a-Glucans 176 A. Pullulan 176 B. Nigeran 180 c. Elsinan 181
III. p-Glucans 182 A. Pachyman 183 B. Schizophyllan 183 c. Scleroglucan 187 D. Other ~-(1---+3),~-(1---+6)-glucans 190
IV. Yeast Cell Wall Glycan 193
V. Chitin, Chitosan, and Other Polyhexosamines 195
VI. Conclusions 197
References 199
I. INTRODUCTION Polysaccharides, or gums, have been used by mankind for a number of purposes for many centuries. These traditionally used polysaccharides originated mainly from plant tissues, including seeds, trees, fruits, or seaweeds. Since the 1950s microbial polysaccharides have been investigated and soon afterward were commercially produced. Their technical application is based on their ability to drastically alter the rheological properties of aqueous solutions at low concentrations. Therefore, these biopolymers are used as thickeners and to stabilize emulsions, dispersions, and suspensions in aqueous systems.
