Optimization of culture conditions and nitrogen sources for production of erythritol by Candida magnoliae

摘要

Culture conditions and nitrogen sources were optimized for production of erythritol, a natural sweetener, by Candida magnoliae M26. The optimal culture conditions were found to be culture temperature of 28 deg C, initial pH of 7, aeration of 1 vvm and agitation speed of 500 rpm in a 2.5 1 jar-fermentor. Glucose was chosen as the best carbon source based on cell growth and erythritol productivity. Light steep water (LSW) and corn steep liquor (CSL) which are by-products in starch processing from corn were tested as a nitrogen source substitute for yeast extract. The use of either LSW or CSL did not change the fermentation performance. The experimental results using LSW and CSL showed 1.5 times higher in cell growth and almost the same value in erythritol productivity compared with the control fermentation using yeast extract as a nitrogen source. These results suggested that either LSW or CSL could be used as a nitrogen source in a large-scale fermentation for erythritol production.