Enzymatic hydrolysis of celluloses obtained via the hydrothermal processing of Miscanthus and oat hulls

Abstract

The enzymatic hydrolysis of celluloses obtained via the refinement of fibrous products after the hydro-thermobaric processing (with an explosion) of two types of feedstocks (Miscanthus and oat hulls) in a high-pressure reactor is studied. A multi-enzyme composition of such enzyme preparations as CelloLux-A, BrewZyme BGX, and Rapidase CR, is used as a catalyst. The celluloses obtained by refining fibrous products from the mentioned feedstocks at a pressure of 1.5 MPa are found to have close reactivities: the yield of reducing substances (RS) was 81% (relative to the substrate weight) and 87–91% (relative to the weight of hydrolyzable compounds). When the pressure of the hydro-thermobaric treatment processing of the feedstocks (Miscanthus) is raised from 1.5 to 2.5 MPa, the fermentability of celluloses diminishes: the RS yield was 53–57% (relative to the substrate weight) or 56–60% (relative to the weight of hydrolyzable compounds). The universality of the hydro-thermobaric processing of different non-wood feedstocks for the subsequent successive fermentolysis of substrates into RS solutions that predominantly contain cellulose is shown. The obtained glucose hydrolyzates are high-quality feedstocks for the biosynthesis not only of fuel alcohols, but also a wide spectrum of such microbiosynthesis products as aminoacids, organic acids, bacterial cellulose jelly films, and protein-vitamin concentrates.