TABLE 1.
Effect of growth under different osmotic conditions on in vivo and in vitro cyclic glucan synthesis
| Growth medium | Cell-associated cyclic glucana | Glucosyltransferase activityb |
|---|---|---|
| GMS | 30.8 | 1.38 |
| GMS + 0.4 M NaCl | 9.7 | 1.42 |
| GMS + 0.4 M NaCl + 10 mM betaine | 15.8 | 1.31 |
a
Cell-associated cyclic glucans were extracted from cell pellets with 70% ethanol, as described in the text. Glucan levels were determined by the phenol-sulfuric acid method after fractionation of the ethanolic extracts by Sephadex G-50 column chromatography. Results are expressed as micrograms of glucose equivalents per milligram of total cell protein.
b
Activity is expressed as nanomoles of UDP-glucose converted to neutral product in a standard in vitro reaction mixture containing 40 μg of membrane protein.