Hydrolysis is usually the rate-limited step for methane production from lignocellulosic substrate. Two bioaugmentation strategies, using the cellulolytic anaerobic bacteria Clostridium cellulolyticum, were adopted to enhance the hydrolysis of wheat straw with the purpose of improving the biochemical methane potential (BMP). Namely, the 24-h-incubated seed (C24S) with cellobiose as carbon source and the 60-h-incubated seed (WS60S) with wheat straw as carbon source were respectively used as the bioaugmentation agents. As a result, the BMPs were respectively 342.5 and 326.3 ml g (1) VS of wheat straw, with an increase of 13.0% and 7.6% comparing to the no-bioaugmentation BMP of 303.3 ml g (1) VS. The result indicates that the anaerobic digestion efficiency can be improved by bioaugmentation, which therefore may be a promising method for improving methane production from lignocellulosic substrate. (C) 2013 Elsevier Ltd. All rights reserved.