Abstract

Gluconic acid production under varying fermentation conditions by Aspergillus spp.

Author(s): S.A.Shaikh, Ratna Trivedi

The production of gluconic acid with respect to varying substrate concentrations in submerged (SmF), surface (SF) fermentations was analyzed. Under the various fermentation conditions the biomass and specific growth rate varied with different concentrations of glucose. The effects of pH, temperature, incubation time and concentrations of carbon were tested in submerged fermentation process in production of gluconic acid by Aspergillus spp. The highest level of gluconic acid was obtained under SmF conditions. In all cases the maximum degree of gluconic acid conversion was observed at on initial substrate concentration of 10gm/100ml. The rate of glucose uptake increased on increasing the initial glucose concentration and glucose utilization was observed to be highest in the SmF process and was comparable with the SSF and SF processes. Themaximumrate of cell growth was obtained in all processes at an initial glucose concentration of 10gm. But in comparison to glucose, sucrose ismore effective than glucose. The gluconic acid production and change in pH were analyzed at varying time intervals and it was observed that the SmF and SF processes were completed within 5 days of incubation whereas the highest yield was observed after 3rd day of incubation and continued thereafter in the SmF process. The increase in production of gluconic acid corresponds to the increase in cell growth instead of Glucose Oxidase (GOD) activity.