Bahaa Talaat Shawky
National Research Centre, Egypt
Title: Biodegradation of cotton stalks for protein-rich feed production by co-cultivation of Pleurotus ostreatus and Azospirillum brasilense grown on solid state fermentation
Biography
Biography: Bahaa Talaat Shawky
Abstract
The alarming rate of population growth has increased the demand for food production leading to a yawning gap in demand and supply. Th e rapid growth, high protein of microbes and their ability to utilize waste feed stocks have made micro-organisms prime candidates for use as animal feed protein supplement. Crop residues are generated in huge quantities, creating disposal problems. Th e potential of co-cultivation of Pleurotus ostreatus and Azospirellum brasilense and evaluation of cotton stalks waste were studied. Solid state fermentation (SSF) off ers advantages for production of protein-rich feed. P. ostreatus, and A. brasilense were assessed for the degradation of chopped cotton stalks. SSF was carried out for 5, 10 and 15 days at 30 °C. Crude protein, cellulose, hemicellulose, lignin, and in vitro dry matter digestibility were analyzed. Activities of ligninolytic enzymes were determined. Th e lignin, hemicellulose, and cellulose in untreated substrate were 23, 27, and 40 %, respectively. Co-cultivation resulted in the degradation of 20 % lignin, 15 % hemicellulose and 17 % cellulose. P. ostreatus degrades lignocellulose with obvious selectivity for lignin. Th e degradation by-products of P. ostreatus was metabolized by A. brasilense, leading to more extensive synergistic use of lignocellulosics, which refl ects on the enhancement of both lignin degradation and in vitro digestibility as well as increased laccase and peroxidase activities. Th e crude protein content of the fermented cotton stalks was 15 %. Extensive studies of single cell protein production for bridging the gap between demand and supply are a major step in this direction.