APPLIED ASPECTS OF COMPOSTING AND BIOCONVERSION OF LIGNOCELLULOSIC MATERIALS - AN OVERVIEW

Huge quantities of lignocellulose containing wastes such as sewage slu dge, refuse, straw, wood and bark are produced worldwide annually. In many instances they pose a significant pollution threat to the environ ment. However, they are also a potentially valuable, virtually untappe d energy source, with endless possibilities as a feedstock for biotech nological upgrading. The varied chemical and physical properties of li gnocelluloses put severe constraints on simple microbiological treatme nt of these materials. The processes outlined in this review have been selected from many as being amongst those most likely to be successfu l. Bioconversion processes which are discussed include landfill gas pr oduction by anaerobic digestion, biopulping and wood utilization, indu strial production and uses of cellulases and production of animal feed s from lignocellulosic wastes. Composting of sewage sludge and municip al wastes are reviewed together with the development of horticultural composts from tree bark. Mushrooms remain the only economically viable product produced from lignocellulosic residues on a world scale, and the cultivation of a variety of edible species is described.