Utilization of Fruit Waste for the Production of Citric Acid by using Aspergillus Niger

Abstract

The main organic acids in industrial used were citric, acetic, tartaric, malic, lactic and gluconic acid. The most utilized organic acid is citric acid or tricarboxylic acid. Chemical synthesis of citric acid is more costly than fermentation. The citrus processing industry generates tons of waste such as peel and segment membranes resulting from the extraction of citrus juice in industrial plants. About 6 isolates were obtained from the fruit waste dumped soil and they were subjected to screening for citric acid production. A. niger over other potential citric acid-producing organism towards efficient utilization of agroindustry residues and by-products for citric acid production. It was grown on PDA plates at a temperature of 28°C for 5 to 7 days. Fruit wastes like orange peel, sweet lime peel, banana peel and pineapple peel as a potential substrate for the production of citric acid using A. niger isolates. The nitrogen source of the fermentation medium will have a direct effect on the yield of citric acid. Among the four fruit wastes, citric acid production was maximum from orange peel followed by sweet lime peel, pineapple peel and banana peel respectively. Orange peel contains soluble sugars and pectin as the main components. Study the impact of different carbon sources on citric acid., the basal media were supplemented with glucose, sucrose, fructose, maltose and the fermentation were carried up to 5 days at 30°C. Nitrogen sources on the fermentation were studied by incorporating ammonium phosphate, potassium hydrogen phosphate and peptone. The effect of lower alcohol incorporation on the fermentation of citric acid was studied.