Biological treatment of solid wastes from the tobacco industry for enzyme production

Abstract

Aiming at the production of enzymes using solid wastes from the tobacco industry, the solid fermentation kinetics of Aspergillus niger and Aspergillus terreus using waste of dark tobacco and Virginia tobacco as substrate were characterized. The efficiency of the fermentation process was evaluated by determining the enzymatic activity of the three enzymes that constitute the cellulose enzymatic system (CMCase, PFase and Xylanase). The results obtained led to the establishment of the best initial conditions of fermentation and the selection of the most efficient microorganism for enzyme production. The best results were obtained with Aspergillus terreus for both tobacco residues. In the case of black tobacco, the best incubation temperature was 31 ºC for the enzymes CMCase and Xylanase and 36 ºC for the PFase and initial pH 5.5 for the three enzymes. For the Virginia tobacco, the best incubation temperature and initial pH are the same for the three enzymes, 36 ºC and 5.5 respectively. The biological activity of the fermented tobacco residues was evaluated being the highest rate of inhibition of microbial growth – 72% - obtained with the residue of Virginia tobacco treated with Aspergillus niger.