Citric acid production by aspergillus niger repeat batch culture using a prickly pear cactus extract medium [electronic resource].

Includes reference.

The potential of prickly pear cactus extract as a fermentation medium for citric acid production by batch and repeat·batch cultures of Aspergillus niger isolated from three locations of Aseer, Saudi Arabia was investigated. Among the 23 isolated cultures of Aspergillus niger, the isolate J6 which obtained from Jazan was found to be enhance citric acid production. Maximum citric acid production (61.56 gIL) was obtained after 8 days of cultivation with an initial pH 4 and 20 % sugar concentration. Better results were achieved when applying repeat-batch culture than batch cultivation. The culture was retained their activity for 24 days of fermentation period and the concentration of citric acid was remained constant during recycle of biomass up to the third batch. A total amount of citric acid of 244.75 g was obtained after five repeated batch-cultivation. On the basis of the experimental results, it was suggested that the prickly pear cactus extract can serve as a low-cost fermentation medium for citric acid production using Aspergillus nigar repeat batch-culture.

Summary in Arabic.

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