Glucose preparation from potatoes

The fact that glycogen phosphorylase can be used to polymerize amylose was first demonstrated by Schaffner and Specht [110] in 1938 using yeast phosphorylase. Shortly after, the same behavior was also observed for other phosphorylases from yeast by Kiessling [111, 112], muscles by Cori et al. [113], pea seeds [114] and potatoes by Hanes [115], and preparations from liver by Ostern and Holmes [116], Cori et al. [117] and Ostern et al. [118]. These results opened up the field of enzymatic polymerizations of amylose using glucose-1-phosphate as monomer, and can be considered the first experiments ever to synthesize biological macromolecules in vitro. 

Results obtained by Leloir and Cardini indicated that two separate enzymes are involved in the biosynthesis, in plants, of sucrose and sucrose phosphate from D-fructose and D-fructose 6-phosphate, respectively in the presence of UDP-D-glucose these enzymes have been partially separated. Slabnik and coworkers succeeded in isolating sucrose synthetase and sucrose 6-phosphate synthetase from potato tubers, and determined some of the properties of the partially purified preparations. The sucrose synthetase showed an optimum activity at 45 and was inhibited completely by ADP and some phenolic D-glucosides, whereas these had no effect on sucrose 6-phosphate synthetase. 

Synthetic amyloses have been prepared from maltopentaose and D-glucose 1-phosphate by the action of potato phosphorylase. The products were characterized by the analysis of the products of /3-amylolysis and were used as standards in the determination of the molecular weight of starches by gel chromatography. 

Glucose is produced from potato starch within 10 h instead of 100 h. It has been produced in the Argonne National Laboratory. The extracted glucose is fermented to lactic acid and purified. The lactic acid from the potato was sufficient to prepare PLLA. These polymers were utilized in the preparation of packing items such as grocery, diaper backing, and food containers. 

A number of polysaccharides can also be prepared using non-Leloir glycosyl transferases. Maltooligomers could be polymerized by potato phosphorylase (PPh, E.C. 2.4.1.1). The activated glucose 1-phosphate in this scheme was generated in situ from sucrose and inorganic phosphate by the action of sucrose phosphorylase (SPh, E.C. 2.4.1.7, Scheme 21) (49). 

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