MECHANISM AND POTENTIAL APPLICATIONS OF BIO-LIGNINOLYTIC SYSTEMS IN ACELSS

A large amount of inedible plant material, generated as a result of pl ant growth in a Controlled Ecological Life Support System (CELSS), sho uld be pretreated and converted into forms that can be recycled on ear th as well as in space. The main portion of the inedible biomass is li gnocellulosic material. Enzymatic hydrolysis of this cellulose would p rovide sugars for many other uses by recycling carbon, hydrogen, oxyge n, and nitrogen through formation of carbon dioxide, heat, and sugars, which are potential foodstuffs. To obtain monosaccharides from cellul ose, the protective effect of lignin should be removed. White-rot fung i degrade lignin more extensively and rapidly than other microorganism s. Pleurotus ostreatus degrades lignin effectively, and produces edibl e and flavorful mushrooms that increase the quality and nutritional va lue of the diet. This mushroom is also capable of metabolizing hemicel lulose, thereby providing a food use of this pentose containing polysa ccharide. This study presents the current knowledge of physiology and biochemistry of primary and secondary metabolisms of basidiomycetes, a nd degradation mechanism of lignin. A better understanding of the lign inolytic activity of white-rot fungi will impact the CELSS Program by providing insights on how edible fungi might be used to recycle the in edible portions of the crops.