corroborated that at temperatures between 24 and 31°C, temperature of 30-31°C was optimum [35, 36]. Temperatures lower than 27°C slowed down growth and production substantially. When the temperature of medium was low, the enzyme activity was also low, giving
Fig. 5: Effect of temperature on citric acid production
Fig. 6: Effect of incubation time on citric acid production
Fig. 7: Effect of cheaper sources on citric acid production
no impact on the citric acid production. However when the temperature of medium was increased above 30°C, the biosynthesis of citric acid was decreased. It might be due to the accumulation of by-products such as oxalic acid [37, 38].
Effect of Incubation Time on Citric Acid Production:
In the present observation 7th day was the optimum incubation time for the production (Fig. 6). In stationary culture, the production starts after a lag phase of approximately after 2 to3 days and reaches maximum at the stationery phase [37].
Effect of Cheaper Sources on Citric Acid Production:
In order to minimize cost of the production cheaper sources were used for the production of citric acid.