A biotechnological process for obtaining citric acid through paper cellulose aerobic bioreaction

Abstract

AbstractThe purpose of this study was to develop a biotechnological process to produce citric acid using paper residues from Urban Solid Waste (USW), like raw material. The selected microorganism to transform degraded cellulose from paper to produce citric acid was Aspergillus niger. The aerobic bioreaction was carried out in a heterogeneous bioreactor. The efficiency of the biotransformation in this study was measured under different operating conditions: 2 and 3 pH levels, 30 and 40 °C temperatures, and high and low concentrations of trace elements: Copper (Cu), Manganese (Mn) and Zinc (Zn). In optimized operation conditions from 20 g of waste paper the maximum citric acid amount obtained was 5.73 g l−1.