Abstract

Biniyam Yalemtesfa , Tesfaye Alemu and Amutha Santhanam

Orange waste consisting of both peel and pulp is highly susceptible to hydrolysis by mixtures of cellulolytic and pectinolytic enzymes which give it potential as feedstock for biological conversion to value added products. Whereas the pulp is relatively rich in carbohydrate, the peel consists of 16.9% soluble sugars, 9.21% cellulose, 10.5% hemicellulose and 42.5% pectin as the most important components. Thus, Aspergillus niger (KA-06) and Chaetomium spp (KC-06) isolated from municipal waste were investigated for their ability to degrade orange waste under solid substrate fermentation (SSF). This study evaluated the influence of various fermentation parameters such as substrate concentration, initial moisture content, Nitrogen source supplementation, inoculum concentration, temperature and pH on the biodegradation of orange waste into protein enriched biomass using A. niger (KA- 06) and Chaetomium spp (KC- 06). The production of protein enriched biomass from orange waste as a substrate for the fermentation process was found to be optimized by moisture content of 40% and substrate concentration of 10 g with inoculum of 106 to 108 spores/ml at 25??? C for both Chaetomium spp (KC-06) and A. niger (KA- 06). The maximum protein content of 39.64% was obtained with Chaetomium spp (KC-06) at inoculum load of 108 spores/ml. A. niger (KA-06) give a protein yield of 31.7% with inoculum load of 106 spores/ml. This research has demonstrated the potential for protein production from orange waste under solid substrate fermentation.