Solid-state fermentation of new substrates for production of cellulase and other biopolymer-hydrolyzing enzymes

Abstract

With the realization that the use of leaded gasoline results in environmental pollution and can effect human health, interest in the use of ethanol either directly or as a gasohol is increasing. Production of ethanol from lignocellulosic biomass was commercially practiced during the world wars by acidic hydrolysis technique. However, these processes were found to be uneconomical after the war emergencies were over. An alternate route is the enzymatic hydrolysis of lignocellulosic biomass. However, the economics of the enzymatic hydrolysis process relies substantially on the cost associated with the production of cellulose enzyme. The liquid-state fermentation technique of cellulose enzyme production involves problems related to maintenance of cellulose concentration, inorganic nutrients, and pH. However, the authors feel that the solid-state fermentation (SF) technique may be more suitable for the large-scale production of cellulose enzyme. The cost of substrate and its potential for the induction and production of cellulose, along with other equally important enzymes, such as xylanase, {beta}-1,3-glucanase, chitinase, and cellobiase enzymes, should be studied by selecting different cheap substrates in the SF process. There are several latex- and resin-bearing plants that contain hydrocarbons and related compounds. These plants are called petrocrops, since these hydrocarbons and related compounds can bemore » extracted from these plants by simple heptane extraction. In the present work, the spent residue (SR) obtained after heptane or hexane extraction was used as a substrate for the production of cellulose and related enzymes by the wheat litter decomposing fungi. The results are reported.« less