Xylitol production by liquid emulsion membrane encapsulated yeast cells

BACKGROUND: Liquid emulsion membrane (LEM)‐encapsulated live cells can be used to produce various products. This work reports on LEM‐encapsulated cells for producing xylitol and models the production process. RESULTS: Encapsulated cells of Candida mogii ATCC 18364 were used to produce xylitol from xylose. Soybean oil LEM consisting of 5% (w/v) lanolin and microwaxes was found most suitable for this process. The LEM‐encapsulated cells were immobilized in a tubular biocatalytic loop. Xylitol was produced under oxygen‐limited and aerobic conditions. Xylitol productivity and yield were 0.005 g L −1 h −1 and 0.52 g g −1 , respectively, for oxygen‐limited operation. Under aerobic conditions, xylitol productivity increased greatly to 0.022 g L −1 h −1 , but yield on xylose declined to 0.49 g g −1 . A mathematical model successfully described substrate consumption and product formation in the LEM‐immobilized cell system. CONCLUSION: Potentially, immobilized cell LEM systems are useful for certain fermentations and they can be successfully modeled, as shown by the example of xylitol from xylose process. Copyright © 2009 Society of Chemical Industry