The hydrolysis of grass hemicelluloses during ensilage

Abstract

The production of reducing sugars, resulting from the incubation of a hemicellulose prepared from Lolium perenne (perennial ryegrass), with enzymes extracted from Lolium perenne, Lolium italicum (Italian ryegrass) and Dactylis glomerata (cocksfoot) was measured over a range of temperature, pH and time. Each of the three enzymes had an optimum pH of 6 but the optimum temperature ranged from 30° to 43°. There was a significant interaction between high temperature and low pH, both tending to suppress enzyme activity. Appreciable amounts of reducing sugars were also produced from hemicelluloses by acid hydrolysis (pH 4) over a 90‐day period. Attempts to grow a number of strains of lactic acid bacteria using hemicellulose as an energy source were unsuccessful. The importance of these findings on the ensilage process is discussed.