CRITICAL ANALYSIS OF THE EFFECT OF METAL-IONS ON GLUCONIC ACID PRODUCTION BY ASPERGILLUS-NIGER USING A TREATED INDIAN CANE MOLASSES

Gluconic acid fermentation by Aspergillus niger has been investigated using untreated and treated Indian cane molasses. The yield of gluconi c acid was found to be reduced using an untreated molasses medium comp ared to a defined medium. Hence, molasses was subjected to various pre treatment techniques. Pretreatment reduced the levels of various catio ns and anions. As the synthesis of gluconic acid has been observed to be influenced more by cations than anions, the effect of various metal ions, viz., copper, iron, zinc, manganese, calcium, and magnesium on the yield of gluconic acid has been critically examined in both untrea ted and treated cane molasses. These results have been compared with a defined medium. The yield of gluconic acid was influenced more by a c ombination of metal ions rather than individual ions. Potassium ferroc yanide treatment gave the most promising results compared to other tre atment techniques.