Effect of osmotic pressure of salts on growth of Torula sp. and erythritol production
1999
Kim, K.A. | Noh, B.S. (Seoul Women's University, Seoul (Korea Republic). Department of Food and Microbial Technology) | Kim, S.Y. (Dong Cheon Consulting Company, Hwasung (Korea Republic).) | Oh, D.K. (Woosuk University, Wanju (Korea Republic). Department of Food Science and Technology)
To investigate the effect of salts on the production of erythritol by Torula sp., cells were grown on the media containing various concentrations of KCl or NaCl. Cell growth and glucose consumption rates decreased when KCl or NaCl concentration increased from 0.0 to 0.5M. The production of erythritol, however, was maximal at 0.3M NaCl or 0.4M KCl. The erythritol concentration of 54.3g/l in the medium containing 0.3M NaCl and 200 g/l glucose was obtained after 120 h. The production of erythritol decreased in cultures above 0.3M NaCl or 0.4M KCl due to the inhibition of cell growth. To elucidate the effect of salts more quantitatively, KCl and NaCl concentrations were converted to osmotic pressure. As the osmotic pressure increased, the yield of erythritol from glucose increased regardless of the kinds of salts and the yield of erythritol was approximately 49% at the osmolality of 2.4 Os/kg. When the osmotic pressure increased to 2.5 Os/kg, the specific growth rate of cells decreased but the production rate of erythritol increased. For the effective production of erythritol, osmotic pressure must be adjusted not to inhibit markedly the growth rate of cells and to stimulate the production rate of erythritol by supplementing salt.
显示更多 [+] 显示较少 [-]