COMPARATIVE-ANALYSIS OF DIFFERENT WHOLE-CELL IMMOBILIZED ASPERGILLUS-NIGER CATALYSTS FOR GLUCONIC ACID FERMENTATION USING PRETREATED CANE MOLASSES

To compare the efficiency of various whole cell immobilization techniq ues for the production of gluconic acid by Aspergillus niger were inve stigated using potassium ferrocyanide-treated cane molasses as the sub strate. The techniques followed were: (1) Calcium alginate entrapment, (2) cross-linking with glutaraldehyde after cell permeabilization wit h (a) acetone, (b) toluene and (c) isopropanol and (3) development of granular catalyst. A comparative analysis of yield has revealed that c alcium alginate entrapment was the most suitable technique as it had g iven the maximum product yield (0.40 g gluconic acid/g total reducing sugar supplied). The properties of immobilized A.niger in sodium algin ate gel have been thoroughly investigated and compared with those of f ree cells under most suitable conditions of fermentation.