A method for glycogen determination in whole yeast cells

✍ Scribed by Jörn Ullrich Becker

• Book ID: 102985258
• Publisher: Elsevier Science
• Year: 1978
• Tongue: English
• Weight: 560 KB
• Volume: 86
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1016/0003-2697(78)90318-4

✦ Synopsis

A method for enzymatic glycogen determination in yeast cells without need for prior disruption of the cell walls has been developed: After stopping cell metabolism with 5% trichloroacetic acid, the cells were digested with 0.25 M Na&O, for 90 min on a boiling water bath and pH was adjusted to 4.8. Glycogen was hydrolyzed by amyloglucosidase (E.C. 3.2.1.3) to glucose, then assayed enzymatically. Hydrolysis was quantitative by the following criteria: (i) Glucose production from the cell residues ceased despite the enzyme still being active, (ii) amyloglucosidaseincubated cell residues lost the iodine staining power, and (iii) no glycogen could be extracted after disruption of the cell walls. (iv) a-Amylase was unable to liberate reducing sugars from amyloglucosidase-incubated cell residues and vice versa. The method has been successfully tested with several strains of Saccharomyces cerevisiae and S. carlsbergensis.