Production, Comparative and Quantitative Analysis of Citric acid by Aspergillusniger using Food Waste as a Substrate

摘要

In this study the main emphasis is given on the techniques by which citric acid can be produced at low cost. The potential of agricultural waste (Apple pomace, carrot waste and pineapple peel) as a substrate was examined for citric acid production by Aspergillus niger using Solid State Fermentation technique. The citric acid concentration and biomass was determined during fermentation period. The amount of citric acid was determined by titration using 0.1 N NaOH and biomass was determined by oven drying method. The optimization of three parameters (temperature, Low molecular weight alcohol and nitrogen source) was carried out. The study revealed that these parameters effect citric acid production extremely. The maximum yield was obtained in case of apple pomace followed by pineapple peel and then the carrot waste. In case of alcohol, 4% methanol gives the maximum yield as compared to isopropyl alcohol. In case of carbon and nitrogen source, sucrose 5% and NH4NO3 0.25% give more citric acid yield as compared with the glucose 5% and NH4NO3 1% respectively. When fermentation media was kept at different temperature the maximum yield was obtained at temperature 30°C as compared with the 4°C. The study has revealed that food waste material can be used for citric acid production by SSF using Aspergillus niger. The use of these wastes might represent an efficient method of reducing the environmental problem due to their disposal and also help in the reduction of the substrate cost.