Abstract

Treated sugarcane bagasse supplemented with sucrose medium was found 1.7 fold (citric acid based on sugar consumption) better substrate than untreated bagasse carrier. The performance of packed bed reactor at aeration rate of 0.75 l/min and apparent packing density of 35.0 g/l was superior with citric acid yield of 55.90% (w/w), overall productivity of 0.087 g/100 g DS.h and specific growth rate of 0.055 h^-1. However, in flask fermentation citric acid yield of 41.56% (w/w) with overall productivity of 0.064 g/100 gDS.h and specific growth rate of 0.043 h^-1 was observed. The system confirmed that citric acid production was Type-II fermentation. Citric acid recovery of 90.39% (w/w) was achieved from fermented broth.

Key words: Aspergillus niger, kinetics, packed bed reactor, sugarcane bagasse.