Citric acid production by Aspergillus niger using banana and plantain peels

Abstract

The production of citric acid by Aspergillus niger using plantain and banana peels were conducted using standard procedures The inoculated substrate was allowed to ferment for 7 days under appropriate temperature and conditions. Physicochemical results of the fermentation process showed that pH decreased from 6.5±0.91/ 6.5±0.54 to 2.5±0.66/ 2.4±0.33 for both banana and plantain peels respectively. Total titratable acidity (%), citric acid yield (%) and biomass content (mg/L) of the fermentation process increased from 0.074±0.49/ 0.06±0.81, 0.172±0.77/ 0.156±0.44, and 64±0.51/ 61±0.08 to 1.28±0.61/ 1.24±0.18, 1.304±0.14/ 1.273±0.32, and 330±0.22/ 298±0.39 for both banana and plantain peels respectively. Sugar content (%) and total solid content (%) for both banana and plantain peels decreased from 7.8±0.23/ 6.3±0.41 and 16.86±0.66/ 18.32±0.08 to 0.6±0.19/ 0.7±0.55 and 9.96±0.22/ 9.34±0.48 respectively. This work has shown that banana and plantain peels which were considered waste products and could not amount to any reasonable use had eventually served as potential substrates for the production of citric acid by Aspergillus niger and their utilization will facilitate both the large scale production of this commercially valuable organic acid and also aid in cleaning up of our messed environment, thereby reducing environmental pollution and improving on waste recycling.