Vol. 7, Issue 6 (2018)

Author(s):
Vidya P, Annapoorani AM and Jalalugeen H

Abstract:
Citric acid is one among the most adaptable organic acid and generally used in different industries including food, cosmetics, pharmacy, beverages and many others. Apart from its consumption as a food additive, citric acid is also considered as a vital component of various pharmaceuticals, synthetic detergents, cosmetics, and many other value-added products. It is predominantly produced by microbial fermentation of Aspergillus niger. The study was conduct to explore the potential of Aspergillus niger AsnO and AsnC (isolated from Orange and Carrot) for citric acid production. These two isolates were screened for citric acid production in Czapekdox agar incorporated with 1% Bromocerol green indicator and were subjected to citric acid production in Czapekdox broth. The effect of different pH, temperature, carbon source, nitrogen source, stimulators and incubation time on citric acid production by the isolate AsnO was analysed. The maximum amount of citric acid production was recorded in carbon source-Sucrose (21.43g/l) at10% concentration (22.78g/l), pH-5.0 (31.64g/l), temperature-30°C (20.33g/l), Nitrogen source-ammonium chloride-(21.83g /l) at 0.3% (28.32 g/l), stimulator- methanol at 1% concentration (22.81g/l) and incubation time 96 hours (45.37g/l). While processing various fruit peel as a substrate for citric acid production, maximum production (11.36 g / l) was obtained from orange peel media followed by pine apple peel media (11.06 g/l), lemon peel media (9.6 g / l) and sweet lime peel media (8.7 g / l).