THE USE OF IMMOBILIZED YARROWIA-LIPOLYTICA CELLS IN CA-ALGINATE FOR CITRIC-ACID PRODUCTION

Citric acid was produced by yeast strain Yarrowia lipolytica A-101 imm obilized in Ca--alginate beads in repeated shaking cultures and a cont inuous process. The best results were obtained for 2% alginate beads c ontaining 10% of biomass. In the continuous process with these gel bea ds, volumetric citric acid productivity was 350 mg/1h. Two methods wer e developed for preparing stable alginate gels in citrate containing m edium. The use of gels treated with chitosan or glutaraldehyde gave th e highest level of citric acid during the third 7-day batch. The gels treated with polyethyleneimine or chitosan and subsequently cross-link ed with glutaraldehyde had about 1.3-fold lower citric acid efficiency than not treated alginate.