Evaluation of Pomegranate Peel as a Substrate for Citric Acid Production by Aspergillus Niger

Abstract

Objective: The present study aimed to evaluate dried pomegranate peels as a substrate for citric acid production by Aspergillus niger.
 Methods: The morphological study of Aspergillus niger was carried out by wet mount with lactophenol cotton blue and slide culture method. A preliminary qualitative screening of citric acid-producing ability of this fungal strain was also performed by using the Czapek-Dox agar medium containing Bromocresol green. Dried and finely powdered Pomegranate peel was used as a principal substrate for the production of citric acid by submerged fermentation. Classical method of citric acid recovery involved a precipitation technique using calcium hydroxide followed by filtration and subsequent treatment with sulphuric acid. The citric acid produced was also chemically detected and titrimetrically estimated by 0.1 N NaOH.
 Results: The present experiment demonstrated that pomegranate peels may serve as an inexpensive medium for the production of citric acid with a yield of 19.39 g/l by using Aspergillus niger.
 Conclusion: This study provided an alternative basis to recycle the fruit peel waste of pomegranate in order to achieve industrially feasible and environmentally sustainable bio-production of pharmaceutically significant citric acid.

Isolation of citric acid-producing Aspergillus niger from soil and organic wastes

“…A. niger isolate NSA05 recorded the largest colour zone diameter at 5.50±0.12 cm while the smallest was seen in isolate NSA13. The colour zone diameter exhibited by NSA05 in the present study was much wider than as reported by Sutradhar et al [25] who recorded much lower diameter at 15 mm or 1.5 cm. However, the study conducted by Sutradhar et al [25] which collected only a single strain of A. niger from laboratory collection, therefore, the observation on citric acid production capacity potentially limited.…”