Bioconvertion of spent cellulose sausage casings

Cellulose sausage cellulose casings are used extensively in the manufacture of sausages in meat packaging. After stripping the meat, spent casings mainly contain cellulose and residual meat juice with salt, nitrate and nitrite. Disposal of spent sausage casings has serious economic and environmental concerns for the sausage industry. This work describes bioconversion of spent cellulose casings (SCC) into enzymes, lactic acid and ethanol by using cellulolytic fungi, lactobacillus and yeasts. The solid substrate cultivation (SSC) of Trichoderma reesei RUT C-30 on SCC and blends gave a maximum of 152 filter paper cellulase (FPase) activity and about 100 carboxymethylcellulase activity (CMCase)/g dry weight substrate. The SSC produced enzyme-rich casing with 50 FPase when directly mixed as such with 10% fresh SCC produced over 70 g/l lactic acid using Lactobacillus plantarum sp. 14431, and also produced 30 g/l ethanol with Kluveromyces marxianus IMB-3 under simultaneous saccharification and fermentation (SSF) conditions.