Abstract
A novel process was developed to simultaneously produce invertase and yeast extract from baker's yeast using ultrafiltration (UF) and microfiltration (MF) membrane processing. After the extraction of invertase under the optimal condition obtained in this study, invertase was separated from yeast cells using a hollow fiber membrane with a pore size of 0.1 $\mu\textrm{m}$. The resulting permeate containing invertase was concentrated using a hollow fiber membrane with a nominal molecular weight cut-off of 30 kDa. The yeast cell and permeate solutions, which were obtained after MF and UF membrane processing, respectively, were mixed together, and the autolysis was performed at 50$^{\circ}C$ in the presence of 5% (w/v) ethanol and 1% (w/v) NaCl. As a result, the yeast extract and invertase could be simultaneously produced from baker's yeast by this novel process.
